Faith Engineering

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2009-12-01T12:03:00.000+07:00

Heating and Cooling from The Ground Up

2009-04-20T00:08:00.004+07:00

As the earliest cave dwellers knew, a good way to stay warm in the winter and cool in the summer is to go underground. Now scientists and engineers are using the same premise—and using existing technology in a new, more efficient way—to heat and cool aboveground homes for a fraction of the cost of conventional systems.

"At any given occasion, the earth temperature is the seasonal average temperature," said Gunnar Walmet, of the New York State Energy Research and Development Authority (NYSERDA). "In New York state, that's typically about 50°F all year long."

Although the average specific heat capacity of earth has a smaller value than the specific heat capacity of air, the earth has a greater density. That means there are more kilograms of earth than there are of air near a house and that a 1°C change in temperature involves transferring more energy to or from the ground than to or from the air. Thus, in the wintertime, the ground will probably have a higher temperature than the air above it, while in the summer, the ground will likely have a lower temperature than the air. An earth-coupled heat pump enables homeowners to tap the earth's belowground temperature to heat their homes in the winter or cool them during the summer. The system includes a network of plastic pipes placed in trenches or inserted in holes drilled 2 to 3 m F to 10 ft) beneath the ground's surface. To heat a home, a fluid circulates through the pipe, absorbs energy from the surrounding earth, and transfers this energy to a heat pump inside the house. The heat pump uses a compressor, tubing, and refrigerant to transfer the energy from the liquid to the air inside the house. A blower- and-duct system distributes the warm air through the home. According to NYSERDA, the system can deliver up to four times as much energy into the house as the electrical energy needed to drive it. Like other heat pumps, the system is reversible.

In the summer, it can transfer energy from the air in the house to the system of pipes belowground. There are currently tens of thousands of earth-coupled heat pumps installed throughout the United States.

Although the system can function anywhere on Earth's surface, it is most appropriate in severe climates, where dramatic temperature swings may not be ideal for air- based systems.

Climatic Warming

2009-04-19T23:40:00.006+07:00

Scientists typically devise solutions to problems and then test the solution to determine if it indeed solves the problem. But sometimes the problem is only suggested by the evidence, and there are no chances to test the solutions. A current example of such a problem is climatic warming.

Data recorded from various locations around the world over the past century indicate that the average atmospheric temperature is 0.5°C higher now than it was 100 years ago. Although this sounds like a small amount, such an increase can have pronounced effects. Increased temperatures may eventually cause the ice in polar regions to melt, causing ocean levels to increase, which in turn may flood some coastal areas.

Small changes in temperature can also affect living organisms. Most trees can tolerate only about a 1°C increase in average temperature. If a tree does not reproduce often or easily enough to "migrate" through successive generations to a cooler location, it can become extinct in that region. Any organisms dependent on that type of tree also will suffer.

But such disasters depend on whether global temperatures continue to increase. Historical studies indicate that some short-term fluctuations in climate are natural, like the "little ice age" of the seventeenth century. If the current warming trend is part of a natural cycle, the dire predictions may be overstated or wrong.

Even if the warming is continuous, climatic systems are very complex and involve many unexpected factors. For example, if polar ice melts, a sudden increase in humidity may result in snow in polar areas. This could counter the melting, thus causing ocean levels to remain stable.

Greenhouse Gases

Most of the current attention and concern about climatic warming has been focused on the increase in the amount of "greenhouse gases," primarily carbon dioxide and methane, in the atmosphere. Molecules of these gases absorb energy that is radiated from Earth's surface, causing their temperature to rise. These molecules then release energy as heat, causing the atmosphere to be warmer than it would bo without these gases.

While carbon dioxide and methane are natural components of the air, their levels have increased rapidly during the last hundred years. This has been determined by analyzing air trapped in the ice layers of Greenland. Deeper sections of the ice contain air from earlier times. During the last ice age, there were about 185 ppm of carbon dioxide, CO2, in the air, but the concentration from 130 years ago was slightly below 300 ppm. Today, the levels are 350 ppm, an increase that can be accounted for by the increase in combustion reactions, primarily from coal and petroleum burning, and by the decrease in CO2- consuming trees through deforestation.

But does the well -documented increase in greenhouse gas concentrations enable detailed predictions? Atmospheric physicists have greatly improved their models in recent years, and they are able to correctly predict past ice ages and account for the energy-absorbing qualities of oceans. But such models remain oversimplified, partly because of a lack of detailed long-term data. In addition, the impact of many variables, such as fluctuations in solar energy output and volcanic processes, are poorly understood and cannot be factored into predictions. To take all factors into account would require more-complex models and more-sophisticated supercomputers than are currently available. As a result, many question whether meaningful decisions and planning can occur.

Risk of Action and Inaction

The evidence for climatic warming is suggestive but not conclusive. What should be done? Basically, there are two choices: either do something or do nothing. The risks of doing nothing are that the situation may worsen. But it is also possible that waiting for better evidence will allow for a greater consensus among the world's nations about how to solve the problem efficiently. Convincing the world's population that action taken now will have the desired benefit decades from now will not be easy.

Acting now also involves risks. Gas and coal could be rationed or taxed to limit consumption. The development of existing energy-efficient technologies, such as low-power electric lights and more efficient motors and engines, could cut use of coal and gasoline in half. However, the economic effects could be as severe as those resulting from climatic warming. But none of these options can guarantee results. Even if the trend toward climatic warming stops, it will be hard to prove whether this was due to human reduction in greenhouse gases, to natural cyclic patterns, or to other causes.

In this formula below (you can have this formula in excel format) we can see, machine tool can be source of air pollute. How many machine tool in the world? As an Engineer we must think this issue for people around us off course for ourself too. Consider it.

Solar Thermal Power Systems

2009-04-18T00:17:00.002+07:00

Because the fossil fuels used to run our generators are being rapidly depleted, we must find new methods of producing electricity. While water and wind power are already in use, the most promising source of electricity may be something Earth has more than enough of— sunlight.

At Sandia National Laboratories, in Albuquerque, New Mexico, engineers are working to harness the sun's energy to generate electricity. One of their projects involves the Stirling engine, a machine that was invented by Robert Stirling in 1816. A large, dish-shaped mirror is used to reflect sunlight onto an absorber, which collects the energy and uses it to increase the internal energy of helium inside the engine. At that point, the engine works much like an automobile engine. The heated helium gas is used to move a piston, but instead of spinning a set of wheels, this piston turns an electric generator.

The Stirling engine operates very efficiently; it holds a world record for converting solar energy into electricity. It is ideal for remote locations, where normal power lines cannot be run, or for power-specific devices, such as water pumps for agricultural purposes.

Sandia is also developing a solar power plant that uses the sun's energy to melt large quantities of salt. The energy transferred as heat from the salt is then used to generate steam, which can turn a turbine to make electricity.

Turbine Rotor

In this rotor you can find many turbine blade that circulate on the body.

Turbine Blade in The Row.

Single Turbine Blade

Once ago we manufactur about 1000 turbine blade for steam turbine. For detail manufacturing you can contact me at +62 818 436 859. We offer you to make that part with good price.

Also, the hot salt can be kept in insulated tanks, which enables the salt's high internal energy to be stored. Previous solar power systems simply heated water to the boiling point, but the water boiled only while the sun was shining. Sandia's salt-heated device stores energy more efficiently than water and maintains the higher temperature long enough to produce electricity even at night.

Greg Kolb, an engineer at Sandia, envisions such a power source replacing the central power stations we have today. "Imagine a tower about the size of the Washington Monument surrounded by a field of mirrors on the ground approximately one square mile in area," Kolb says. "The mirrors are reflecting the sunlight to the top of the tower, where all the light is focused and the energy is absorbed in a large heat exchanger." The engineer estimates that about 10.000 such setups spread throughout the nation could provide as much energy as the United States consumes annually.

Material Development

2009-04-17T10:56:00.007+07:00

Impervium? Eternium? What do you call a nearly unbreakable metal? Dr. Richard Waterstrat has been pondering that question ever since he invented an alloy that is nearly impervious to wear. Several years ago at the National Institute for Standards and Technology, Dr. Waterstrat was developing a metal for use in artificial hips and knees. Because the alloy would be implanted into the human body, it needed to be both nontoxic and crack-resistant. He made one alloy by mixing three metals— zirconium, palladium, and ruthenium. The alloy seemed promising, so Dr. Waterstrat sent it down to the machine shop to prepare a sample for testing. Soon after, Dr. Waterstrat received a call from a worker in the shop who reported that he was unable to cut the alloy in a lathe, using conventional meth- methods. At first, Dr. Waterstrat thought that the metal might simply be too hard to cut. But closer examination revealed that a very thin fibrous layer had formed wherever force had been applied to the metal. The crystalline structure of the alloy's surface had changed in response to the force to prevent new damage. The metal had actually "healed itself." "The new crystals are harder and stronger than the original crystals," Dr. Waterstrat explained, "and that reinforces or 'heals' the defects that form as a result of the applied stress, making the material, in fact, stronger than it was to begin with. So the unusual wear-resistance is due to the fact that the metal is continually forming crystals under stress to resist further wear." Dr. Waterstrat's alloy not only was resistant to cracking but also was found to be nearly impervious to wear. He submitted the alloy to a test to measure its wear-resistance, its ability to withstand intense wear over a long period of time. After a pin was rubbed against the metal for 5 million cycles, the alloy showed practically no wear. Artificial joints are constantly subjected to wear, so it seemed that Dr. Waterstrat had finally found his ideal metal. While the alloy is still being perfected for use in joint replacements, there are other applications for which it might be used. Any piece of metal that is subject to extreme wear, such as drill bits, bearings in machinery, or needles in sewing machines, could be coated with the wonder metal. The alloy also seems to be corrosion-resistant, suggesting that it could be used as the metal contact in an electric circuit, a part that is constantly subjected to high wear and corrosion.

As engineer we know high wear resistant contradict with high toughness. Research for this characteristic also demand. SS400 is a material from steel grade that have tensile strength 41kg/mm2 and carbon contain below standard of hardenability. But recently my instructor develop some technic to improve SS400 because is cheap yet we can get the benefit for it strength.

After some experiment SS400 can achieve surface hardness 70HRc and the core still have toughness characteristic. That can be apply for spring steel or even cutting tool material. He use carbon from animal bone for medium for carburizing process.

As can see on the part below, all are made from low carbon steel SS400. Cutting Tool, spring part and machinery gear application.

Die & Mould Sector

2009-04-14T10:57:00.008+07:00

Moulding To Changing Time
The business of producing dies and moulds is a highly integrative effort involving machines, tools, software, and people.
Making moulds and dies is not just about cutting tools and scraping metal from work-blocks, but a careful combination of the process drivers. It is a team effort on the part of everybody that has enabled the die/mould making sector to face up to the challenge of demands of diverse natures from a slew of manufacturing sectors, and come out trumps. However, there are some loose ends still to be tied.Apart from integrated effort, individual initiatives in changing process setups in
mould shops, opting for high-performance tools etc, have also been instrumental in the success of the die/mould makers the world over.

If the diversities of demand across different end-user sectors is studied, the plastics sector stands out for obvious reasons - large variety of products, smaller product lives, and most importantly, the competition in the marketplace, where a new entrant in a particular category, needs to introduce new features into his product, to get an edge over the others already operating in the market.

Market Growth Scenarios
Many die/mould makers are keen on expanding their markets to other parts of the world, such as Southeast Asia and China. One reason is the burgeoning automotive sector, which consumes a hefty amount of dies/moulds for the fabrication of automotive parts. That is good news for die/mould makers in Asia and Australasia, as well as those in the West who have a market in Asia.

While on Asia, one cannot miss India. The ever-burgeoning auto components sector, whose exports rely a lot on good quality moulds and dies (zinc and aluminium alloy die-casting units are doing big business selling carburettors, automotive door locks, etc), on the one hand, and the cash-rich stainless steel utensils sector on the other hand, are driving the growth in the domestic die/mould industry. The dies used by the utensil manufacturers are typically those employed for bending, drawing and deep drawing operations. Considering the volumes of stainless steel kitchenware which emerge out of shops in the country, and also keeping in mind the tremendous export potential that these products have, this sector is certain to be a sustained area of
demand for die makers. A look at the variety of utensils – shapes and sizes – would set the mind racing to the innumerable dies that may have been employed to fashion them.
The small-scale Indian entrepreneurs who specialise in die-making, are now no longer plagued by the lack of finances.
Low-interest loans are there for the asking; for investments in technological upgrading at the die-making shops.
CAD/CAM software and CNC machines are now affordable, and the quality of these dies and the life thereof will also be improving, resulting in timely fulfillment of export orders.

Material Developments
For the plastics sector, it has been a case of ‘aluminium to the rescue’. Steel moulds are still common, when there is not much pressure on delivery times on the mould maker, and when the end-user is a small-scale manufacturer, whose output is limited by a modest demand for his products. However, when the demand in the marketplace increases, the moulds will have to be overworked.
Cost and functional superiority would be the guiding criteria that the mould maker would base his decisions on. The result: the steel may have to go, making way for aluminium alloys. The addition of magnesium, copper, zinc and silicon in varying proportions to aluminium, enhances its functional properties (while being machined, as well as while being used to mould the end products). The trigger here is the demand for a mould which will increase the number of products moulded every day.

Aluminium Economics
There have been total transitions of late, from steel-mould-making setups to aluminium-mould-making ones. Toolcraft Plastics of the UK is one of the latest to be bowled over by the advantages of aluminium. The said company incidentally, has an in-house mould-making unit, the moulds from which are employed not just for its own plastics production, but also sold in the market to other plastics producers. Early this year, TPSL managed to bring down its production time considerably, while cutting down the cost by 30 percent.
This tallies with Alcan’s (the leading aluminium producer in the world) economic analysis of the mould construction and utilisation phases, for aluminium (the Certal brand) and steel (Ck45 steel). Aluminium is costlier than steel by approximately 60 percent, but the machining and energy costs are less than half of those for steel. This more than offsets the extra costs incurred while purchasing the material. For a given weight of material, for every steel mould, 2-3
similar aluminium moulds can be made.

Tool Concepts For Die & Mould
HITACHI is one company that has been focusing developing new tool geometries, inserts and cutting tool materials for high performance cutting (HPC) of dies and moulds. These developments aim to improve performance, productivity and profitability. The introduction of the tools for very high feed, plungers for high productivity in machining deep cavities, and
drills for high efficiency in drilling are some examples.
Optimisation of the insert and chipformer geometry in milling, drilling, and profiling improves accuracy of the machined surface, provides more tool life, reduces cutting forces and vibration and makes fast metal removal (FMR) possible. For roughing applications on dies and moulds, new tooling technologies such as plunging tools, ramp-down tools or milling cutters with helical cutting edge inserts like are used.

• Helical Inserts

ATC and ATB from Hitachi Tool
Helical inserts have been developed for shouldering, facing, slotting and profiling This type of tool solves the main
geometrical disadvantages which are the lack of workpiece side wall straightness, flatness, and perpendicularity of a
straight cutting edge insert positioned with a positive axial angle. Inserts are made of submicron substrate with improved toughness and hardness, better resistance to chipping, and high wear resistance.
The TiCN coated tools are recommended for most of the standard applications in machining alloy steel and tool steel materials. The TiAlN coated tool is an excellent grade for hard machining, dry cutting, and on high-temp alloys. The machining of dies and moulds made of alloy-steel in the soft and hardened state with the new PVD-TiAlN coated tools improves tool life significantly.

• Facing With Very High Feed

ASR Type EndMill can withstand the maximum 20m/min or more, cutting feed rate of the latest machining equipment. Compare with Bull Mill from Taegutec is not efficient for Indonesian workshop because need high tech machine and price too expensive.
For facing with very high feed rates HITACHI has developed a special super radius-shaped positive insert having a cutting-edge configuration with a very large radius. In this unique FEEDMILL geometry the relative small insert design with positive rake angles is recommended for small depth of cuts and very high feeds providing easy chip flow, lower cutting forces and a stable operation. The tools can be used for fast metal removal in machining dies and moulds with deep cavities with large overhangs at very high feeds, up to 3.5 mm per tooth.

• Profile Shaping With Very High Feed

ETM EndMill is the best endmill i ever use.

Moves In Machining
Just as one material has replaced another in moulds for certain applications, there are numerous instances of one machining process being replaced by another, superior to the former in certain respects. One such is trochoidal milling, which has proved to be a more efficient and quicker (by some 30 percent) method of machining fillets, pockets, slots and grooves in moulds, as compared to conventional milling.

In conventional milling, the cutting tool moves along straight-line paths, and the machining of a curved contour, involves the formation of a series of steps at right angles to each other, which are then progressively flattened out to form a continuous curve. This calls for a series of finishing operations. Besides, manual polishing is required as a final step to even out the inevitable aberrations.

In trochoidal milling, however, the cutting tool moves about along a curved path, which in geometry could be termed as a ‘trochoid’ ie: the curve traced by a point within a rolling circle, which is not its centre, between the end-points specified in the CNC program. The ‘step formation’ typical of the conventional milling method, is not characteristic of trochoidal milling,
and manual polishing which accounts for a significant portion of machining time in conventional milling, is almost entirely dispensable.

Software Solutions
Software is now a major component in the mould and die process. There are many CAD/CAM software suppliers in the market today, distinguished from one another by the features they provide, as well as by the nature of the after-sales service that is extended to the clients in the global market.
Vero International, NC Graphics and Delcam all have a strong presence in the die/mould sector; in fact, a majority of their clients belongs to this sector. Vero International Software’s VISI-series CAD/CAM software has recently been upgraded to include applications for 3D component design, plastic mould tool design, sheet metal tool design, progressive die design, 2D CAM, 3D CAM, continuous 5-axis machining, wire EDM and high speed milling. The 5-axis machining module enables the spindle (and a short tool) to be inclined to reach otherwise inaccessible nooks and crannies inside the mould – deep cavities and small radii. This spindle-adjustability obviates the need for tool extensions or longer tools, which would involve problems of deflection and poor surface finish.

The Message: Get Integrated
Early this year, a pan-European team working on a two-year, EU-sponsored project, emould@work, which attempted to find out what ailed the die/mould makers in the EU, published its findings, after studying the operations at several units.
Stuart Watson of Delcam, the Project Leader summarised the findings of the team for MEN:

• Communication/collaboration problems: Almost half the lead-time for a mould is spent on waiting for data, changing poor data, discussing such changes, etc. Basically, integration between the design stage and the machining/assembly stage leaves a lot to be desired.

• Poor process flow: Nearly 50 percent of the mould makers around the world are working in two parallel streams with the core/cavity done using a 3D surface modeller and the mould assembly done in 2D using a 2D drafting system. The others have replaced 2D drafting by solid modelling, but still have two departments because the solid modeller in vogue cannot do the core/cavity work, while surface modeller cannot accomplish the solid assembly modeling. This, inevitably,
creates a lot of idle time.

In a nutshell, it is not enough if the mould machining department is well equipped with the best CNC machines and highspeed
cutting tools. The design stage has to be seamlessly integrated into the manufacturing stage.
The suggestions of the emould@work project team can be extended to the other parts of the world. If there is a difference, it would just be a matter of degree.

High Technology = High Risk for Mankind

2009-04-14T10:34:00.007+07:00

What Can We Do With Nuclear Waste ?

For about the past 40 years, people have been arguing about what to do with radioactive waste. Since the waste is harmful to humans—as well as to the environment— deciding where to put it is a serious problem.

Protection for 10 000 years

As radioactive isotopes decay, nuclear waste emits all common forms of radioactivity-alpha-particles, beta-particles, gamma-radiation, and X rays. When this radiation penetrates living cells, it knocks electrons away from atoms, causing them to become electrically charged ions. As a result, vital biological molecules break apart or form abnormal chemical bonds with other molecules. Often, a cell can repair this damage, but if too many molecules are disrupted, the cell will die. This ionizing radiation can also damage a cell's genetic material (DNA and RNA), causing the cell to divide again and again, out of control. This condition is called cancer. Because of these hazards, nuclear waste must be sealed and stored until the radioactive isotopes in the waste decay to the point at which radiation reaches a safe level. Some kinds of radioactive waste will require safe storage for at least 10 000 years.

Questions of disposal

Low-level waste includes materials from the nuclear medicine departments at hospitals, where radioactive isotopes are used to diagnose and treat diseases. The greatest disposal problem involves high- 892 level waste, or HLW. Nearly all HLW consists of used fuel rods from reactors at nuclear power plants; about a third of these rods are replaced every year or two because their supply of fissionable uranium-235 becomes depleted, or spent. When nuclear power plants in the United States began operating in 1957, engineers had planned to reprocess spent fuel to reclaim fissionable isotopes of uranium and plutonium to make new fuel rods. But people feared that the plutonium made available by reprocessing might be used to build bombs, so that plan was abandoned. Since that time, HLW has continued to accumulate at power plant sites in "temporary" storage facilities that are now nearly full. When there is no more storage space, plants will have to cease operation. Consequently, states and utility companies are demanding that the federal government honor the Nuclear Policy Act of 1982 in which the federal government agreed to provide permanent storage sites.

Disposal possibilities

Any site used for disposal of HLW must be far away from population centers and likely to remain geologically stable for thousands of years. One possibility lies at certain deep spots of the oceans, where, some scientists claim, the seabed is geologically stable as well as devoid of life. Sealed stainless-steel canisters of waste could be packed into rocket-shaped carriers which would bury themselves deep into sediments when they hit the ocean bottom. Opponents say that the canisters have not been proven safe and that, if released, the radioactivity could kill off photosynthetic marine algae that replenish much of the world's oxygen. Proponents claim that the ocean bottom already contains many radioactive minerals and that the radioactivity from all HLWs in existence would not harm marine algae. Scientists in the United States have considered other proposals as well, but since the Nuclear Policy Act of 1982, most of the attention has focused on the development of a disposal site beneath Yucca Mountain in Nevada. The design of this site includes sloping shafts that lead to a 570 hectare A400 acre) storage area 300 m deep in the mountain's interior. The U.S. Department of Energy is committed to developing Yucca Mountain. Engineers believe that it will be 2010 before the site is ready to receive waste. Until that time, there is a plan to begin moving HLW from power plants to a remote interim site in a western state. HLW would be transported to the storage site by truck or rail in sealed, steel canisters placed inside reinforced shipping casks.

Objections to Yucca Mountain

There are two main sources of opposition to the Yucca Mountain plan. One source maintains that Yucca Mountain has not been proven to be geologically secure, citing evidence that gases emitted at the lowest depth were able to reach the outside air. In addition, the group is concerned about the possibility of collisions or other accidents that might break the casks open while in transport. The Department of Energy claims it has proven the casks safe. Several tests have been performed, including one in which a cask was loaded onto a flatbed trailer and crashed into a concrete wall at 135 km/h. In another test, a cask was struck by a locomotive at 130 km/h. No leakage occurred in these tests. The other source of opposition to Yucca Mountain are people who maintain that the costs of overcoming legal challenges will ultimately make the plan financially infeasible. These people believe that the government should stop spending money on the Yucca Mountain project and resume the plan to reprocess waste to make new nuclear fuel.

Conclusion
Like I said on previous page. The bad thing we can't throw away as easy as we can imagine. We must face it and try to build a good thing for next.

Perspectivity of Nuclear Reaction

2009-04-14T09:22:00.011+07:00

FISSION AND FUSION

Any process that involves a change in the nucleus of an atom is called a nuclear reaction. Nuclear reactions include fission, in which a nucleus splits into two or more nuclei, and fusion, in which one or more nuclei combine.

Stable nuclei can be made unstable

When a nucleus is bombarded with energetic particles, it may capture a particle, such as a neutron. As a result, the nucleus will no longer be stable and will disintegrate. For example, protons can be released when alpha particles collide with nitrogen atoms, as follows:

According to this expression, an alpha particle (4He) strikes a nitrogen nucleus ( 14N) and produces an unknown product nucleus (X) and a proton (1H). By balancing atomic numbers and mass numbers, we can conclude that the unknown product has a mass number of 17 and an atomic number of 8. Because the element with an atomic number of 8 is oxygen, the product can be written symbolically as 170, and the reaction can be written as follows:

This nuclear reaction starts with two stable isotopes—helium and nitrogen— that form an unstable intermediate nucleus (18F). The intermediate nucleus then disintegrates into two different stable isotopes, hydrogen and oxygen. This reaction, which was the first nuclear reaction to be observed, was detected by Rutherford in 1919.

Heavy nuclei can undergo nuclear fission

Nuclear fission occurs when a heavy nucleus splits into two lighter nuclei. For fission to occur naturally, the nucleus must release energy. This means that the nucleons in the daughter nuclei must be more tightly bound and therefore have less mass than the nucleons in the parent nucleus. This decrease in mass per nucleon appears as released energy when fission occurs, often in forms such as photons or kinetic energy of the fission products. Because fission produces lighter nuclei, the binding energy per nucleon must increase with decreasing atomic number. Figure 25-8 shows that this is possible only for atoms in which A > 58. Thus, fission occurs naturally only for heavy atoms.

One example of this process is the fission of uranium-235. First, the nucleus is bombarded with neutrons. When the nucleus absorbs a neutron, it becomes unstable and decays. The fission of 235U can be represented as follows:

The isotope 236U* is an intermediate state that lasts only for about 10 -12 s before splitting into X and Y. Many combinations of X and Y are possible. In the fission of uranium, about 90 different daughter nuclei can be formed. The process also results in the production of about two or three neutrons per fission event. A typical reaction of this type is as follows:

To estimate the energy released in a typical fission process, note that the binding energy per nucleon is about 7.6 MeV for heavy nuclei (those having a mass number of approximately 240) and about 8.5 MeV for nuclei of intermediate mass (see Figure 25-8 ). The amount of energy released in a fission event is the difference in these binding energies (8.5 MeV - 7.6 MeV, or about 0.9 MeV per nucleon). Assuming a total of 240 nucleons, this is about 220 MeV. This is a very large amount of energy relative to the energy released in typical chemical reactions. For example, the energy released in burning one molecule of the octane used in gasoline engines is about one hundred-millionth the energy released in a single fission event.

Neutrons released in fission can trigger a chain reaction

When 235U undergoes fission, an average of about 2.5 neutrons are emitted per event. The released neutrons can be cap- captured by other nuclei, making these nuclei unstable. This triggers additional fission events, which lead to the possibility of a chain reaction, as shown in Figure 25-9. Calculations show that if the chain reaction is not controlled—that is, if it does not proceed slowly—it could result in the release of an enormous amount of energy and a violent explosion. If the energy in 1 kg of 235U were released, it would equal the energy released by the detonation of about 20 000 tons of TNT. This is the principle behind the first nuclear bomb.The first nuclear fission bomb, often called the atomic bomb, was tested in New Mexico in 1945.

A nuclear reactor is a system designed to maintain a controlled, self- sustained chain reaction. Such a system was first achieved with uranium as the fuel in 1942 by Enrico Fermi, at the University of Chicago. Primarily, it is the uranium-235 isotope that releases energy through nuclear fission. Uranium from ore typically contains only about 0.7 percent of 235U, with the remaining 99.3 percent being the 238U isotope. Because uranium-238 tends to absorb neutrons instead of undergoing fission, reactor fuels must be processed to increase the proportion of 235U so the reaction can sustain itself. This process is called enrichment. At this time, all nuclear reactors operate through fission. One difficulty associated with fission reactors is the safe disposal of radioactive materials when the core is replaced. Transportation of reactor fuel and reactor wastes poses safety risks. As with all energy sources, the risks must be weighed against the benefits and the availability of the energy source.

Light nuclei can undergo nuclear fusion

Nuclear fusion, the opposite of nuclear fission, occurs when two light nuclei combine to form a heavier nucleus. As with fission, the product of a fusion event must have a greater binding energy than the original nuclei for energy to be released in the reaction. Because fusion reactions produce heavier nuclei, the binding energy per nucleon must increase as atomic number increases. As shown in Figure 25-8 , this is possible only for atoms with A less than 58. Hence, fusion occurs naturally only for light atoms. One example of this process is the fusion reactions that occur in stars. All stars generate energy through fusion. About 90 percent of the stars, including our sun, fuse hydrogen and possibly helium. Some other stars fuse helium or other heavier elements. The proton-proton cycle is a series of three nuclear- fusion reactions that are believed to be stages in the liberation of energy in our sun and other stars rich in hydrogen. In the proton-proton cycle, four protons combine to form an alpha particle and two positrons, releasing 25 MeV of energy in the process. The first two steps in this cycle are as follows:

This is followed by either of the following processes:

The released energy is carried primarily by gamma rays, positrons, and neutrinos. These energy-liberating fusion reactions are called thermonuclear fusion reactions. The hydrogen (fusion) bomb, first detonated in 1952, is an example of an uncontrolled thermonuclear fusion reaction.

Fusion reactors are being developed

The enormous amount of energy released in fusion reactions suggests the possibility of harnessing this energy for useful purposes on Earth. Efforts are under way to create controlled thermonuclear reactions in the form of a fusion reactor. Because of the ready availability of its fuel source—water—controlled fusion is often called the ultimate energy source.

For example, if deuterium (2H) were used as the fuel, 0.16 g of deuterium could be extracted from just 1 L of water at a cost of about one cent. Such rates would make the fuel costs of even an inefficient reactor almost insignificant. An additional advantage of fusion reactors is that few radioactive byproducts are formed. The proton-proton cycle shows that the end product of the fusion of hydrogen nuclei is safe, nonradioactive helium. Unfortunately, a thermonuclear reactor that can deliver a net power output for an extended time is not yet a reality. Many difficulties must be resolved before a successful device is constructed. For example, the energy released in a gas undergoing nuclear fusion depends on the number of fusion reactions that can occur in a given amount of time. This varies with the density of the gas because collisions are more frequent in a denser gas. It also depends on the amount of time the gas is confined. In addition, the Coulomb repulsion force between two charged nuclei must be overcome before they can fuse. The fundamental challenge is to give the nuclei enough kinetic energy to overcome this repulsive force. This can be accomplished by heating the fuel to extremely high temperatures (about 108 K, or about 10 times greater than the interior temperature of the sun). Such high temperatures are difficult and expensive to obtain in a laboratory or a power plant.

Perspectivity

Sometimes fission reaction in business strategy can make explosive growing for us but more explosive growing if we can develop fusion reaction in our business. Many years past, I am making partnership with some friend. Its good. But you must have the right motivation then you can get experiences in it. All of that good for build our character.

CAMCAD WorkNC

2009-04-01T22:22:00.001+07:00

The biggest change happening in the CAM industry isn’t in the software products themselves, but in the way CAM companies must now do business. Their customers are moving away from controlling everything within the four walls of a single plant and toward a global supply chain.
In this scenario, tasks are distributed to wherever they provide the most value to the manufacturer, which means that departments within the same company may be hundreds or even thousands of miles apart. In this type of distributed work environment, manufacturers expect software companies to provide solutions that work regardless of where their employees, subcontractors or manufacturing plants are located.
New advances in machine tool technology have also kept the CAM industry on its toes. The complexity of these machines requires advanced technology to program them efficiently and simulate all aspects of the machine motion.

In 2005 I work at PT PrimaTigon. We are agent of Software CAMCAD WORKNC.

Advanced algorithms are used to calculate the shape of the toolpath for high-speed machining. This smooth, flowing, tool engagement-controlled motion can run at much higher feedrates, spindle speeds, depths-of-cut and stepovers while producing a superior finish. Image courtesy of Surfware, Inc.
Global Manufacturing Is Changing the Way CAM Software Is DevelopedNew manufacturing requirements are forcing CAM companies to take a closer look at their software development processes and sales distribution networks in order to deliver their products and software support to all countries where manufacturing plants are located.

Traditionally, American software developers would release the English version of their product and then translated versions would follow a few months later, but that luxury is no longer possible. Global manufacturers are demanding a simultaneous release that includes all languages so that non-U.S. plants don’t lag behind their U.S. counterparts in software technology. In addition, customers want support in every country where they run manufacturing plants. No one wants to deal with multiple time zones and language barriers to get a question answered.
For smaller CAM companies, these harsh new realities have forced some to recognize that they simply cannot afford to provide this type of global support. For larger companies with already hefty marketing and distribution budgets, it may not be feasible to increase development costs to gain access to niche markets in specific countries. This has led to increased CAM industry consolidation, where a larger company with a well-established global network acquires a smaller company that produces an excellent product in a specific niche.
The popularity of multi-task machines is due in large part to their ability to fully machine a variety of parts in a single setup. The complexity of programming these machines is easily handled in the latest CAM systems.

More Emphasis on Reliability and SpeedCAM customers fall into two broad groups: those who need to produce CNC programs as quickly as possible and those who need to produce CNC code that machines as efficiently as possible. In either case, users are increasing their demand for more reliable code. CAM developers are putting more consideration into making their systems easier to use, but the real emphasis has been on generating more efficient code that shaves seconds and minutes from every machining cycle.
CAM developers realize that a slick interface makes their system easier to sell, but the real bread and butter for any shop is producing parts as quickly and reliably as possible. To improve profitability for their customers, CAM companies have decided to allocate the majority of their development resources to improving cycle speeds and software quality while taking into consideration the overall user experience as an added bonus.
As the complexity of machine tools continues to increase, the ability to accurately simulate all machine motion has gained critical importance to avoid costly mistakes on the shop floor.

Hard Milling and High-Speed MachiningTraditional CAM toolpaths are the bane of high-speed machining because they allow sharp changes in tool direction, which require sharp reductions in the feedrate to avoid tool breakage. To eliminate this problem, CAM companies have developed specialized toolpaths that use mathematical algorithms to calculate the shape of cutter paths based on maintaining a constant cutter load. This is accomplished by analyzing the amount of material in contact with the tool at any given time and adjusting the cutting path to prevent the tool from ever becoming overengaged. These new toolpaths are particularly well-suited to machining hardened materials, parts with thin walls where tool pressure becomes a factor, and for utilizing the full capabilities of high-speed machining centers.
Although these advanced algorithms were developed for high-speed machines, they’ve proven very beneficial to all machine shops regardless of the type of CNC machines they currently have on the floor. A constant cutter load produces less pressure and vibration from the tool, which not only supports faster feedrates and faster spindle speeds—at greater depths-of-cut than traditional toolpaths—but also extends tool life and machine life as well.
Hard milling presents unique challenges to tool- and diemakers. The majority of this mold was milled using a short tool and three-axis strategies. The CAM system identified all areas of the toolpath where the tool couldn’t reach and easily converted those sections to five-axis toolpath.
For hard milling applications, companies are using shorter tools to improve rigidity. The problem is that these tools cannot reach into deep cavities. Some CAM companies have resolved this issue by allowing the user to cut as much of the toolpath as possible with three-axis milling strategies. When the software senses a tool or holder collision, the toolpath can be split and converted to a five-axis cutter path.
Programming for Multi-Task MachinesMulti-task machines that combine milling and turning on multiple spindles and multiple turrets with live tooling have become far too complex to program manually. Advanced CAM technology now offers better support for multi-axis, multi-spindle and multi-turret machines to get the most out of these investments. This is largely due to the partnerships that CAM developers have forged with machine tool builders so that CAM technology can be developed in step with machine tool advancements.
Realistic Machine SimulationWith so many moving components on new machine tools, particularly multi-task machines, it has become critically important to simulate every aspect of a machining operation to ensure that machine components, tools and parts don’t collide.
Many CAM systems now support the simulation of all machine movement, not just the part, tool and toolholder. Solid models are used for any machine component the user wants to simulate, with each assigned a type of movement: fixed, linear (X, Y, Z), or rotary motion (A, B, C). Motion for each component also can be defined in relation to other components. For example, it’s possible to define a turret with the B-axis mounted on an X-axis mounted on a Y-axis mounted on a Z-axis.
Industry Consolidation Will ContinueAs the CAM industry continues to mature, more consolidation will take place. Only companies with a worldwide distribution and support network will be able to survive. CAM companies will continue to focus their development efforts in specific niche markets where they can outshine the competition and increase collaboration with other software developers to reduce development costs.
It’s a more effective business strategy to license or purchase specific technology that’s already been developed by experts than it is to develop everything in-house. That way, a customer can pick and choose the right solutions for their manufacturing environment and purchase them all from the same vendor.
The result of this consolidation and collaboration is a better focus on specific industries such as molds, progressive dies and others. This provides a single point of contact for software support. Stronger partnerships with CAD companies, machine tool builders, cutting tool manufacturers, and machine controllers help everything work together as new technology is developed.

Thinwall Molding Plastic

2009-03-30T19:25:00.004+07:00

Molding parts with thinner wall sections has been prevalent in the packaging industry for many years, but the know how developed in packaging items is limited to the polyolefins and styrenics used in that product area.The benefits of thinwall molding are now sought in technical applications such as cellular phones and notebook computer housings.

When I was a worker at PT Nagai Plastic Indonesia, we produce printer part for PT Epson Indonesia. We are specialize in big part such as housing, coverprinter, paper support and stacker paper. Our facility has 80 Ton till 960 Ton injection machine and as a Maintenance Supervisor, I have to keep that facility work well everytime.
These parts has thinner wall section almost every section. Especially on the rib. Many rib for wall part support. Off course many problem appear. But many merit too. Lighter, smaller parts molded with less resin and fastercycle times are being produced which translate into lower unit costs for themolder. However, these products require higher viscosity engineering polymers such as PC, ABS, and PC/ABS blends, which raises new challenges. Part design,resins, processing, and molding equipment are all impactedand there is a need for boosting performance requirements to meet the high speeds and pressuresdemanded. New hot runner designs play a key role.
Thinwall molding can be defined as either wall sections of less than 1.5 mmor flow length over wall thickness ratios (L/T) of greater than 100. By eithermeasure, thinwall molding pushes conventional molding equipment to the limitby its effect on the flow area as shown in the following example.

Flow path for thinwall molding is 1/10th that of conventional molding

The nominal wall thickness of conventional vs. a thinnwall design are 3.0 mm and 0.75 mm, respectively.In both cases as the molten resin travels throughthe mold, a skin layer is formed approximately 0.25 mm thick immediately atthe mold wall. The resulting flow paths are cut to 2.5 mm for the conventionalmolding and 0.25 mm for thinwall. Reducing the thinwall flow area to just one-tenth that of conventional molding can push standard molding equipment beyond its limits.
The high injection speeds and pressures employed in thin wall molding to overcome this reduced flow path narrow the process window, but higher performance equipment widens the window sufficiantly to produce precision parts. In order to produce thinwall parts, an injection molding must be able to meet these three requirements :

High injection speeds and pressures;
Rugged large clamp/small injection unit combination;
High performance controls and hydraulics.

Fill times of less than 0.5 s are typical in thinwall molding in order to fillthe mold before the skin layer builds up and blocks the flow channel.An injection unit equipped with an accumulator can achieve such rapid fill times. The accumulator allows for near instantaneous delivery of a largevolume of oil to the injection cylinder during fill. The accumulator shouldbe located as close as possible to the injection cylinder in order to minimize pressure drop and maximize responsiveness. This also reduces the amount of fittings and hoses which are a potential source of leakage.

Filled resins are used in some thinwall applications to impart necessary performance characteristics. Glass and graphite fillers of up to 20% by weight are used which results in excessive wear to the runner system, particularlyat the gate area where the resin experiences high shear rates and often makes a 90 deg. turn to enter the cavity. Standard beryllium copper tips should be replaced with more wear resistant materials that also provide high conductivity, easy access, and replaceability.Thinwall molding with engineering resins places new demands on injection molding equipment. High pressure, precision molding requires higher performance machines and hot runners that are specially suited to meet these rquirements.

Machine Tool

2009-03-28T15:59:00.008+07:00

First month after graduation in 1995, I am a Sales Engineer of Machine Tool at PT. Super Adi Teknik. We sell many brand of machine tool such as Kitamura for CNC Milling Machine

A machine tool is a powered mechanical device, typically used to fabricate metal components of machines by the selective removal of metal. The term machine tool is usually reserved for tools that used a power source other than human movement, but they can be powered by people if appropriately set up. Many historians of technology consider that the true machine tools were born when direct human involvement was removed from the shaping or stamping process of the different kinds of tools. For instance, they consider that lathe machine tools were invented around 1751 by Jacques de Vaucanson because he was the first to mount the cutting instrument on a mechanically adjustable head, taking it out of the hands of the operator.
Machine tools can be powered from a variety of sources. Human and animal power are options, as is energy captured through the use of waterwheels. However, machine tools really began to develop after the development of the steam engine, leading to the Industrial Revolution. Today, most are powered by electricity.
Machine tools can be operated manually, or under automatic control. Early machines used flywheels to stabilize their motion and had complex systems of gears and levers to control the machine and the piece being worked on. Soon after World War II, the NC, or numerical control, machine was developed. NC machines used a series of numbers punched on paper tape or punch cards to control their motion. In the 1960s, computers were added to give even more flexibility to the process. Such machines became known as CNC, or computer numerical control, machines. NC and CNC machines could precisely repeat sequences over and over, and could produce much more complex pieces than even the most skilled tool operators.
Before long, the machines could automatically change the specific cutting and shaping tools that were being used.

For example, a drill machine might contain a magazine with a variety of drill bits for producing holes of various sizes. Previously, either machine operators would usually have to manually change the bit or move the work piece to another station to perform these different operations. The next logical step was to combine several different machine tools together, all under computer control. These are known as machine centers, and have dramatically changed the way parts are made.

Today, it is possible to design a complex part on a computer, put a bar or rod into a machine center, and have a finished part within a matter of minutes.

Examples of machine tools are:

- Broach

- Drill (like mill, but optimized to make holes)
- Gear shaper
- Hobbing machine
- Lathe (work rotates, single-edge cutter is fixed)
- Milling machine (work is fixed, multi-edge cutter rotates)
- Shaper Stewart platform mills
- Grinders

When fabricating or shaping parts, several techniques are used to remove unwanted metal. Among these are:

EDM (electrical discharge machining)
Grinding
Multiple edge cutting tools
Single edge cutting tools

Other techniques are used to add desired material. Devices that fabricate components by selective addition of material are called rapid prototyping machines.

Workshop with various Machine Tool

High Tech 5 Axis Machine

Bench Work Practice

2009-03-20T01:53:00.004+07:00

When i am accepted as a student on Swiss Project on Politechnic for Mechanic ITB, in first year we are trained how to use manual tool such as handsaw, chisel and file. We have to make some shape as drawing to make sure the dimension tolerance is not run out. Whatever the shape is we don't allow to use machine tool. For example my name is Patrisisus Iwan, so i have to make first letter of my name that is 'P' letter. From unshape raw material must be shaped like P with tight dimension tolerance. For some student is a boring practice. You imagine that from 7 am till 2 pm frommonday to thursday in one year. On friday and saturday we study theoritical matter. Actually that practice build your sense of benchwork and machine tool. Because we are dealing with very tight tolerance you can say 50micron till 10micron so we must have enough skill for that job.

One case my customer Ishikawa corp want their mold to be modified. Their customerwant a 0,4mm round shape in their part. I make a electrode from copper.I cut it using lathe machine then i am finishing with file to shape it about 0,4mm. Because i think maybe is just for aesthetic matter,i just use manual tool. A file.The electrode i make then put it in EDM (Electro Discharge Machine) as cutting tool to cut the mold.

Using High Technology such as CNC EDM we just simply choose the parameter we want speed, surface finish and dimension tolerance etc.

With this machine you do not have to finishing like polishing this machine can achieve 0,1micron surface finish.

After finish i send the mold already modified for trial in plastic injection machine.

That surprise me is they cut the injection part in four section then they check it with Visual Projector. The result is good with plus minus 0,05mm. Wow... close enough.

Thanks to the 1 year practice.

Leak Test Machine

2009-03-15T19:08:00.008+07:00

Leak Test Machine is used for showing any leaking on the component or sub assy component.Leakage is a process in which material is lost, intentionally or accidentally, gradually through the holes or defects of their containers. The material lost is usually fluid, usually liquid or powder and sometimes gas, from an imperfectly sealed container Many industries use this equipment for their component;
1. Chemical plant

2. Petrochemical plant: hydrocracker, vapocracker, catalytic reforming, steam reforming are all Hydrogen based processes were Hydrogen leak testing will be very appropriate,

3. Semiconductor industry; all processes taking place in a process chamber at atmospheric pressure or under vacuum; Diffusion, Oxidation, LPCVD, PECVD, PVD, Etch, Ion Implant, typically the later that implies vacuum will require Helium leak testing, while the other will make good use of Hydrogen leak testing,

4. Automotive: with airbag being the most demanding leak testing application (small gas tank, very high pressure, long shelf life) and air conditioning system (for best efficiency), fuel system (for low emission), exhaust system (for lowest pollution), engine and transmission (for no oil dripage), rims to keep tyre safe,

5. Medical: to ensure safe and long life implant (pacemaker) or a safe catheter

6. Airplane: to quickly and safely locate fuel leaks , to check oxygen distribution devices and cabin pressurization systems

7. Refrigeration and air conditioning systems-residential, commercial or industrial- in order to deliver best efficiency at the lowest loss rate of refrigerant gases (ozone depletion)

8. Power distribution for high voltage circuit breaker using SF6 as a dielectric

9. Drinking water distribution grid as today average leakage rate or efficiency is above 25%, wasting precious resources, water and power.

10.Sewage water collecting network as leaks can contaminate drinking water collection process;

Once ago we build a Leak Test Machine for Suzuki Motor Corp, for testing leakageon theirs part Cylinder Head Motor (combustion chamber and exhaust system).We make machine base,jig and mechanic parts.

For electric parts we use branded part as Fuji,Mitsubishi for PLC, Cosmo for Leakage Main Control,etc.

For pneumatic parts we use Festo Indonesia's parts. After we assemble all together, the system doesn't work. We doing check the control system or the cylinder head part is not good. Finally we find error in the control system. We change the pneumatic parts from Festo to SMC especially the micro valve then the system work well. But this cut US$ 3000 my profit.

Knuckle Washing Machine

2009-03-12T03:15:00.007+07:00

I'm not realize how important cascade method to solve pneumatic problem untill i have a case . While ago i'm just ordinary student on Swiss Project in Politechnic for Mechanicin Bandung. I like technic but for study theoritically that a part i'm too lazy for. When i follow pneumatic lesson i like it but theoritically i don't catch it too much.

Eleven years later i must open my pneumatic book again.

My customer Tsuzuki Asama need a washing machine to wash off the car's component name is knuckle.After pass several cnc machine process that part must be washed through water contain anti rust agent. The part put in tray and that tray is moving up and down actionmoved by pneumatic cylinder.They want that machine is fully pneumatic without electric component.

Here is the challenge.

The action can be controlled, timing, how many times up and down action how deep is down level and other thing without use PLC.That is easy for professional but for me..feuwww.I try to design pneumatical scheme for that and try and try again. But stillcan not work. Then i open my lesson book about automation. I read again because already 11 years ago that i never read it well. And then i found about cascade method but still i can't understand it. After read well in a hour i found usage of motion diagram and control diagram are solve my problem.

Ceramic Component

2009-03-11T03:01:00.002+07:00

Ceramic is made of clay then expose to heat reach up to 1300 degree C

or about 4000 degree F. Before heating process must lay on open air to

drop offwater contain from mold part.
My friend need component made by ceramic, because he try many

component made by many material like steel, alloy steel, carbide, etc.

The component use for carry something that must through heating

process by conveyor system.

He found that Ceramic more useful.

Ceramic mold is simple has three part body, top plate and bottom plate.

Material is put on the body part assy with bottom plate then put on top

plate then press it by press machine.

Thats it.

3D Design Interior and Animate It

2009-03-07T23:56:00.004+07:00

Build a house or a construction site need good planning if not after finish it

we realize that is not our want.And if we want some modification or rebuilt

is not as simple as we make something like make castle from sand in the

beach.It need high investment. We can build it first in 3D design so we can

look around observe our design then we can make some modification or

redesign again if we don't want it.We can try various texture for our wall,

roof or furniture inside it.After we satisfy with our design , then the

construction company do the rest.

This design request by Indofood Corp to make meeting room in their office.

We can explore every detail of our room's design.

With 3D design software we can build everything in virtual dimension.

Try it!Its fun.

Palm Oil Processing Machine

2009-03-06T09:03:00.010+07:00

Research and development work in many disciplines -biochemistry, chemical and mechanical engineering - and the establishment of plantations, which provided the opportunity for large-scale fully mechanised processing, resulted in the evolution of a sequence of processing steps designed to extract, from a harvested oil palm bunch, a high yield of a product of acceptable quality for the international edible oil trade. The oil winning process, in summary, involves the reception of fresh fruit bunches from the plantations, sterilizing and threshing of the bunches to free the palm fruit, mashing the fruit and pressing out the crude palm oil. The crude oil is further treated to purify and dry it for storage and export.
Large-scale plants, featuring all stages required to produce palm oil to international standards, are generally handling from 3 to 60 tonnes of FFB/hr. The large installations have mechanical handling systems (bucket and screw conveyers, pumps and pipelines) and operate continuously, depending on the availability of FFB. Boilers, fuelled by fibre and shell, produce superheated steam, used to generate electricity through turbine generators. The lower pressure steam from the turbine is used for heating purposes throughout the factory. Most processing operations are

automatically controlled and routine sampling and analysis by process control laboratories ensure smooth, efficient operation. Although such large installations are capital intensive, extraction rates of 23 - 24 percent palm oil per bunch can be achieved from good quality Tenera.
Conversion of crude palm oil to refined oil involves removal of the products of hydrolysis and oxidation, colour and flavour. After refining, the oil may be separated (fractionated) into liquid and solid phases by thermo-mechanical means (controlled cooling, crystallization, and filtering), and the liquid fraction (olein) is used extensively as a liquid cooking oil in tropical climates, competing successfully with the more expensive groundnut, corn, and sunflower oils.
Extraction of oil from the palm kernels is generally separate from palm oil extraction, and will often be carried out in mills that process other oilseeds (such as groundnuts, rapeseed, cottonseed, shea nuts or copra).

The stages in this process comprise grinding the kernels into small particles, heating (cooking), and extracting the oil using an oilseed expeller or petroleum-derived solvent. The oil then requires clarification in a filter press or by sedimentation. Extraction is a well-established industry, with large numbers of international manufacturers able to offer equipment that can process from 10 kg to several tonnes per hour.

Alongside the development of these large-scale fully mechanised oil palm mills and their installation in plantations supplying the international edible oil refining industry, small-scale village and artisanal processing has continued in Africa and Indonesia. Ventures range in throughput from a few hundred kilograms up to 8 tonnes FFB per day and supply crude oil to the domestic market.
Efforts to mechanise and improve traditional manual procedures have been undertaken by research bodies, development agencies, and private sector engineering companies, but these activities have been piecemeal and uncoordinated. They have generally concentrated on removing the tedium and drudgery from the mashing or pounding stage (digestion), and improving the efficiency of oil extraction. Small mechanical, motorised digesters (mainly scaled-down but unheated versions of the large-scale units described above), have been developed in most oil palm cultivating African and Asian countries.
Palm oil processors of all sizes go through these unit operational stages.

They differ in the level of mechanisation of each unit operation and the interconnecting materials transfer mechanisms that make the system batch or continuous. The scale of operations differs at the level of process and product quality control that may be achieved by the method of

mechanisation adopted.

The general flow diagram is as follows:

PALM OIL PROCESSING UNIT OPERATIONS

Harvesting technique and handling effects
In the early stages of fruit formation, the oil content of the fruit is very low.

As the fruit approaches maturity the formation of oil increases rapidly to about 50 percent of mesocarp weigh.

In a fresh ripe, un-bruised fruit the free fatty acid (FFA) content of the oil is below 0.3 percent.

However, in the ripe fruit the exocarp becomes soft and is more easily attacked by lipolytic enzymes, especially at the

base when the fruit becomes detached from the bunch. The enzymatic attack results in an increase in the FFA of the

oil through hydrolysis. Research has shown that if the fruit is bruised, the FFA in the damaged part of the fruit increases rapidly to 60 percent in an hour. There is therefore great variation in the composition and quality

within the bunch, depending on how much the bunch has been bruised.

Harvesting involves the cutting of the bunch from the tree and allowing it to fall to the ground by gravity. Fruits may be damaged in the process of pruning palm fronds to expose the bunch base to facilitate bunch cutting.

As the bunch (weighing about 25 kg) falls to the ground the impact bruises the fruit. During loading and unloading of bunches into and out of transport containers there are further opportunities for the fruit to be bruised.

In Africa most bunches are conveyed to the processing site in baskets carried on the head. In Indonesia some do that but now mostly by truck bring bunches. To dismount the load, the tendency is to dump contents of the basket onto the ground. This results in more bruises. Sometimes trucks and push carts, unable to set bunches down gently, convey the cargo from

the villages to the processing site. Again, tumbling the fruit bunches from the carriers is rough, resulting in bruising of the soft exocarp. In any case care should be exercised in handling the fruit to avoid excessive bruising.

One answer to the many ways in which harvesting, transportation and handling of bunches can cause fruit to be damaged is to process the fruit as early as possible after harvest, say within 48 hours. However the author believes it is better to leave the fruit to ferment for a few days before

processing. Connoisseurs of good edible palm oil know that the increased FFA only adds ‘bite’ to the oil flavour. At worst, the high FFA content oil has good laxative effects. The free fatty acid content is not a quality issue for those who consume the crude oil directly, although it is for oil

refiners, who have a problem with neutralization of high FFA content palm oil.

The main point of clarification is to separate the oil from its entrained impurities. The fluid coming out of the press is a mixture of palm oil, water, cell debris, fibrous material and ‘non-oily solids’. Because of the non-oily solids the mixture is very thick (viscous). Hot water is therefore added to the press output mixture to thin it. The dilution (addition of water) provides a barrier causing the heavy solids to fall to the bottom of the container while the lighter oil droplets flow through the watery mixture to the top when heat is applied to break the emulsion (oil suspended in water with the aid of gums and resins). Water is added in a ratio of 3:1.
The diluted mixture is passed through a screen to remove coarse fibre.

The screened mixture is boiled from one or two hours and then allowed to settle by gravity in the large tank so that the palm oil, being lighter than water, will separate and rise to the top. The clear oil is decanted into a reception tank. This clarified oil still contains traces of water and dirt.

To prevent increasing FFA through autocatalytic hydrolysis of the oil, the moisture content of the oil must be reduced to 0.15 to 0.25 percent.

Re-heating the decanted oil in a cooking pot and carefully skimming off the dried oil from any engrained dirt removes any residual moisture. Continuous clarifiers consist of three compartments to treat the crude mixture, dry decanted oil and hold finished oil in an outer shell as a heat exchanger.

In next year our team will plan to build small scale CPO (5 tonnes FFB/day) processing for remotes area of Indonesia especially Sumatra island for first priority.

We make machine processing from FFB to CPO and CPO to cooking oil and bar soap. For oil that are produced from kernel is used for medical industry.

Many farmer could not process their bunches because of CPO price is too low or already decompose on the way to the factory. With this small scale machine process, they can process by themself for their welfare.

So we prepare for all technic manufacturing and make improvement on machine so can used by unskill man(the farmer itself).

Food Processing Plastic Component

2009-03-05T23:51:00.002+07:00

Indofood Corp has conveyor system is used for carry away wheat flour

from bottom site to hopper on top of food processing machine.Conveyor

has some bucket rotate on railway system. Material made of plastic

PA6 (nylon) or PP.

They need bucket replacement and they give me sample.Before that they

already search the available plastic maker to make it.Many maker give a

quotation US$ 10,000.00-20,000.00 for 400x700x350mm mold size

with 1 cavity investment and US$ 8.00 for production cost of that part.

I just give price 40% from that above price for mold and US$ 7.00 for

production cost. Because they just need only 200pcs of bucket. So the

mold doesn't have to use mold steel and the tolerance isn't too precisely.

Deal!

I take the sample to reverse engineering it just with ruler and

pocket caliper. Go to mold design process within many consideration,

machine ability, dead line,cost and handling.Our machine ability only

400x600mm process stroke.Whoala! design ok get ready to machine

process. To speed up i divide the process one part on our machine one

part to subcontractor.

Subcon A(Stalion)give a quotation US$ 600.

Subcon B(Coppal) give US$ 2000.

I give it to Stalion.

After mold is finish we deliver to AA Plastic Corp to make plastic part

using injection machine 550Ton.And then i send that part to Indofood.

They happy we are happy too.

How to Think Design then Create

2009-03-04T01:00:00.004+07:00

How to think design and create something stage by stage :

First of all of course think about something and create it in mind.
Then make a sketch about it.

For make it more realistic design it by 3D software like UG,ProE,Catia
or SolidWorks

If that request from second party must has approval or next discuss
about it.
We can share it with face to face and if this is far distance bussiness we
can share by mail. We can save the design as application file or
presentation file like eDrawings format. So the second party can see
our design even they don't have 3D software. The file can be eDrw ,
exe or html file that still the second party can use the file as 3D format
when they receive it. They can rotate it or display manipulate it as 3D.

If there is modification they can put a mark or information on the
design then send it back to us. If they approve after that we can use
the design for marketing purpose like advertise it, we can use software
rendering like 3DMax atau Vray SketchUp.

For create it we can use several method by machining, mold or hand
making.
By machining example are used by CNC router or CNC milling for
precision reason.

3D Design and 3D Machining

2009-03-03T02:29:00.011+07:00

WHAT YOU THINK IN YOUR MIND
WE CAN DESIGN IT FOR YOU
WHAT YOU HAVE IN YOUR HAND
WE CAN REVERSE ENGINEERING FOR YOU
WHAT YOU NEED IN YOUR LIFE
WE CAN CREATE IT FOR YOU

With CNC Mill HURCO VMX24 (GERFA Trading Company)we can
create 2D and 3D part/component/equipment/souvenir with
dimension 400x600x400mm. For dimension bigger than that
using 'split technology'. Using cutting tool like Hitachi
(PrimaTigon Trading Company) ASR HighFeed Mill with
insert EPNW and ETM Solid Carbide EndMill will speed up
our process. The price are cheaper than Taegutec Tool or
Sandvick but result higher.

Die Making Optimizing

2009-03-02T02:22:00.007+07:00

Die Making Optimization Methodology
1. Identify the best process and flow
2. Implement 3-D design and manufacturing
3. Implement High Performance Machine and Tool

1. Identify the best process and flow

Analyzing the formability of the material early in the development

cycle to allow for product design optimization.

Predicting metal flow during the stamping process.
Determining the final dimensions of the stamped part.
Preventing flow induced defects such as excessive thinning of

material and wrinkling.

Reducing amount of scrap material.
Increasing die life.
Use software for optimize design like DIESTAMP, FAST BLANK,

FASTFORM etc.

2. Implement 3-D design and manufacturing

With Curvature radius analysis we can determine cutting tool we used
in machining process so all surfaces can be cut perfectly.

Press Part Example

Modification on dies is needed as drawing
specification. Dies must have additional radii for material spring in.

3. Implement high performance machine and tool

As we can see this graphic, "Processing costs" have highest initial cost

that need cost down.
Usage of machine and tool effectively can achive with the formula below :

After that we can create some simulation from machining software with

various cutting strategy to get quality and machining time as fast as

possible relate to the machining cost effeciency.

Machining time can be observed everytime we run a simulation.
Conclusion :

There are some problem that may appear in case doing the machining
process from a design part.

1. Process translate or converte from customer's drawing file to another
CAD software or CAM software, it can happened format distortion or
interference format on surface part.
CAM software read all surface contour into G-code/cutting movement
on machine, hence many case the result from process machining did not
macth with the original drawing or design.
2. So that all surface can be machined all surface contour must known
by CAM operator to determine tool usage.

If surface contour can not known than surface contour is not cut perfectly
that in conventional technnic depend mostly in die spotting/die setting
machine to cu manually by portable grinding tool or files or another
equipment.
Today mostly CAD/CAM software already adopted all above features.
The difference only in display and familiar icon to access that features.

Plastic Recycle

2009-03-01T19:35:00.003+07:00

IT'S PLASTIC!
Americans seem to have a love–hate affair with plastic. We look down

on plastic imitations of natural products and fibers. They are cheap, we

say. We all want real leather, for example, rather than imitation plastic.
Yet we are using plastic products more than ever before. We cover our

food in plastic wrap, drink coffee from Styrofoam® cups, wear clothes

made from man-made fibers like nylon, polyester, and rayon, and even

buy our plastic things with plastic credit cards! We use plastic hundreds

of times every day.
Plastic is a versatile product. Plastic can be flexible or rigid; transparent

or opaque. It can look like leather, wood, or silk. It can be made into toys

or heart valves. Altogether there are more than 10,000 different kinds

of plastics. The basic raw materials for plastic are petroleum and/or

natural gas. These fossil fuels are sometimes combined with other

elements, such as oxygen or chlorine, to make different types of plastic.
Plastics are not the waste and energy culprits that some people think

they are. Plastics are really very energy efficient. It takes 20-40

percent less energy to manufacture plastic grocery bags than paper

ones. And, since plastics are lightweight and take up so little space,

it is much more efficient to transport them. It takes seven trucks to

deliver the same number of paper bags as can be carried in one

truckload of plastic bags.

DECODING PLASTICS

PET Polyethylene Terephthalate Two-liter beverage bottles,

mouthwash bottles, boil-in-bag pouches.
HDPE High Density Polyethylene Milk jugs, trash bags, detergent bottles.
PVC Polyvinyl Chloride Cooking oil bottles, packaging around meat.
LDPE Low Density Polyethylene Grocery bags, produce bags, food

wrap, bread bags.
PP Polypropylene Yogurt containers, shampoo bottles, straws,

margarine tubs, diapers.
PS Polystyrene Hot beverage cups, take-home boxes, egg cartons, meat

trays, cd cases.
OTHER All other types of plastics or packaging made from more than

one type of plastic.

DISPOSING OF PLASTIC ANOTHER look PLASTICS RECYCLING IN

AMERICA

Today, Americans recycle only 5 percent of all the plastics produced in

this country. Why aren’t we recycling more? There is no simple answer.
Part of the issue in recycling plastics is the cost. To remain competitive

in the global marketplace, manufacturers usually choose the cheapest

option for making products. New plastic resin, or virgin resin, often costs

less than recycled plastic. Until recently, when the U.S, experienced

massive hurricanes, virgin resin was cheaper than recycled plastic.

After the hurricanes in 2005, supplies of oil and natural gas--the building

blocks of virgin resins--became limited and more expensive. Prices for

virgin resin soared, and the demand for recycled plastics increased.
Another important consideration is human behavior. Surveys conducted

by Proctor & Gamble and other companies show that while most people

expect their plastic to be recycled, they won't go out of their way or pay

a few cents more to buy products made of recycled plastic.
There are success stories in plastics recycling, nonetheless. Soft-drink

bottles made of polyethylene terephthalate (PET) can be melted down

and made into carpet, t-shirts, stuffing for ski jackets, or molded into

bottles again. In 1999, Ford Motor Company used more than 60 million

2-liter plastic soda bottles (7.5 million pounds) to make grille

reinforcements, window frames, engine covers and trunk carpets for

its new vehicles.

In recent years, several plastics recycling companies have closed their

doors. They claimed they could not sell their products at a price that

would allow them to stay in business. Thanks to the relatively low cost

of petroleum today, the price of virgin plastic is so inexpensive that

recycled plastic cannot compete. The price of virgin resin is about 40

percent lower than that of recycled resin.
Because recycled plastic is more expensive, people aren’t exactly lining

up to buy it. Surveys conducted by Procter & Gamble and others show

that while most people expect their plastic to be recycled, they won’t go

out of their way or pay a few cents more to buy a bottle made of recycled

plastic. Recyclers say plastics recycling won’t be profitable until we close

the loop by creating more demand for recycled plastics.
Soft-drink bottles, however, are one success story in plastics recycling.

Made of polyethylene terephthalate (PETE), they can be melted down

and made into carpet, t-shirts, stuffing for ski jackets, or molded into

bottles again. When a soft-drink bottle is recycled into another soft-drink

bottle, the loop is closed.
Is plastic trash choking the Earth with Styrofoam® cups and fast-food

plates? Not really. That’s just another misconception. By weight, plastics

make up about 11 percent of America’s municipal solid waste.

In comparison, paper makes up about 35 percent.
Of course, plastics are generally very lightweight. When plastics are

buried in a landfill, they occupy about 25 percent of the space. Putting

plastics into landfills is not always the best disposal method. There are

two other alternatives: recycling and incineration.
These methods recover some of the value from the plastic. Recycling

recovers the raw material, which can then be used to make new plastic

products. Incineration recovers the chemical energy, which can be used

to produce steam and electricity. Landfilling plastics does neither of

these things. The value of landfilled plastic is buried forever.
RECYCLING PLASTICS
Recycling plastics is easy. First, you should learn what types of plastics

can be recycled and only give your collector those types of plastics.
Resist the temptation to slip plastics that recyclers don’t want into the

recycling bin. Plastics have different formulations and should be sorted

before they are recycled to make new products. Mixed plastics can be

recycled, but they are not as valuable as sorted plastics because the

recycled plastic’s physical properties, such as strength, may vary with

each batch.
Once you know what kinds of plastics your recycler wants, you should

follow the wash and squash rule—rinse the container and squash it.

You may leave the paper labels on the container, but throw away the

plastic caps. Plastic caps are usually made from a different type of plastic

than the container and cannot be easily recycled.

HOW PLASTIC IS RECYCLED
A recycling plant uses seven steps to turn plastic trash into recycled

plastic:
1. Inspection Workers inspect the plastic trash for contaminants like rock

and glass, and for plastics that the plant cannot recycle.
2. Chopping and Washing The plastic is washed and chopped into flakes.
3. Flotation Tank If mixed plastics are being recycled, they are sorted in

a flotation tank, where some types of plastic sink and others float.
4. Drying The plastic flakes are dried in a tumble dryer.
5. Melting The dried flakes are fed into an extruder, where heat and

pressure melt the plastic. Different types of plastics melt at different

temperatures.
6. Filtering The molten plastic is forced through a fine screen to remove

any contaminants that slipped through the washing process. The molten

plastic is then formed into strands.
7. Pelletizing The strands are cooled in water, then chopped into uniform

pellets. Manufacturing companies buy the plastic pellets from recyclers

to make new products. Recycled plastics also can be made into flowerpots,

lumber, and carpeting.

ENERGY FROM PLASTIC
Because plastics are made from fossil fuels, you can think of them as

another form of stored energy. Pound for pound, plastics contain as much

energy as petroleum or natural gas, and much more energy than other

types of garbage. This makes plastic an ideal fuel for waste-to-energy

plants.
Waste-to-energy plants burn garbage and use the heat energy released

during combustion to make steam or electricity. They turn garbage into

useful energy. So, should we burn plastics or recycle them? It depends.

Sometimes it takes more energy to make a product from recycled plastics

than it does to make it from all-new materials. If that’s the case, it makes

more sense to burn the plastics at a waste-to-energy plant than to recycle

them. Burning plastics can supply an abundant amount of energy, while

reducing the cost of waste disposal and saving landfill space.
PAPER OR PLASTIC?
A paper cup or a plastic cup? Should you choose paper cups over plastic

cups since the paper cups are made from natural wood products and will

degrade? Not if the plastic cup is polystyrene (another name for Styrofoam®).
A study by Canadian scientist Martin Hocking shows that making a paper cup

uses as much petroleum or natural gas as a polystyrene cup. Plus, the paper

cup uses wood pulp. The Canadian study said, “The paper cup consumes

12 times as much steam, 36 times as much electricity, and twice as much

cooling water as the plastic cup.” And because the paper cup uses more

raw materials and energy, it also costs 2.5 times more than the plastic

cup. But the paper cup will degrade, right? Probably not. Modern landfills

are designed to inhibit degradation so that toxic wastes do not seep into

the surrounding soil and groundwater. The paper cup will still be a paper

cup 20 years from now.

Learn more about how long it takes buried trash to disappear.
DEGRADABLE plastic
Degrade is another word for rot. It’s nature’s way of getting rid of dead

plants and animals or the things made from them. Of course, plastics

are man-made materials, but scientists have figured out two ways to

make plastics degrade: biodegradation and photodegradation.
Biodegradable plastics are made with five percent cornstarch or vegetable

oil. The idea is that hungry bacteria will devour the starch or oil in the

plastic, causing the plastic to disintegrate into a fine dust. That is the idea,

but does it really work? No, say both environmentalists and plastics

manufacturers. Nothing degrades quickly in a modern landfill, not even

organic wastes like paper and food scraps, so there is no reason to think

that the corn starch in biodegradable plastics will disappear overnight

either. Modern landfills are designed to inhibit degradation, not promote

it. The idea is to keep wastes in, so landfill contaminants do not seep into

the surrounding environment. In addition, biodegradable plastics cannot

be recycled because the starch or oil additive compromises the quality

of recycled plastics.
Photodegradable plastics are a different matter. They use no organic

additives. They are made with a special type of plastic that breaks down

and becomes brittle in the presence of sunlight. Of course, that means

photodegradable plastics do not break down when they are covered by

leaves or snow, or when they are buried in a landfill.
The maker of the plastic six-ring carrier that is used to attach six cans of

soda, beer, and other beverages, says its photodegradable carrier loses

75 percent of its strength when exposed to sunlight after just a few days,

and totally disintegrates within a matter of weeks. This means if an animal

were to become entangled in the six-ring carrier, it could rip through the

weakened pack to free itself. Since photodegradable plastics contain no

organic additives, they can also be recycled, unlike their biodegradable cousins.

Last Revised: September 2006Source: National Energy Education

Development Project, Museum of Solid Waste , 2006

D40D Die Project

2009-02-28T23:54:00.004+07:00

Grand Max is minibus vehicle launch
at 2007 by Daihatsu Corp. in Indonesia.
Inside this car you can find a component
named is Oil Pan beside the engine.
For maintenance reason old oil came
out from that component before new
oil fill in to the engine tank.

And that is our first project. I quit in
2006 from my ex company KBU Corp
maker of car chassis part,car seat and
body shop for minibus and bus.
Oil Pan Assy contain of several part and must be assembly together by
welding process and mechanic joint. Daihatsu Corp point to Asno Horie
Corp to handle the assembly production and Asno Horie point to SJM
Corp for tooling (stamping die) manufactur and production that part
(Oil Pan Component). But after long negotiation between our team
and Asno Horie(of course we make impress them by show them our
partner facilities Politechnic Manufacturing ITB or my ex academy
that have such a high tech facility like PAMSTAMP and
CNC PlanoMill Mitsubishi), they decide to give the contract for die
manufacturing to us.

The progress it seem is like smoothly way but we realize many internal
affair involve in this project. You know money sometimes make people
side out the professionalism. First problem is the drawing doesn’t perfectly
convert to simple drawing that ready for machining. You know as
technician or engineer you want your design can transport to machining
process as simply as you can make so that will minimize human error
especially for precision part. And second is SJM refuse to trial the tooling
on their factory although the agreement mention that.. But thanks to
our partner Stalion Corp and Mr. Lily’s team we can accomplish this project.
My point is even in technical industry that suppose to be give high
priority on professionalism isnot like “politics” you know what I meant,
people is trapped in their esteem and of course belly’s problem.

If you want 3D this part , 3D stamping die for this part, checking fixture,
welding jig, schedule program or document quality system of this part
just feel free to contact me.
Thank you for reading this.

Lubricating Media

2009-02-20T05:17:00.002+07:00

Solid Film Lubricants: A Practical Guide
Mike Johnson, Noria Corporation

It is widely believed that extreme conditions are uncommon; however
nearly every
manufacturing plant has at least one application in which the operating
conditions could be characterized as extreme from a lubrication perspective.
Common extremes could include high and low shaft speeds, high and low
temperatures, high pressures, concentrated atmospheric and process
contaminants, and inaccessibility.
Mineral oil-based fluid lubricants (oil and grease materials) function properly
where the designed surface areas and shaft speeds allow for the effective
formation of an oil film, as long
as the machine operating temperature envelope falls between -20°C and
100°C
(-4°F to 212°F). The only absolute limits that apply for fluid lubricants,
regardless of the base oil type, are conditions that cause a change in the
state of the fluid that prohibits fluid film formation. Fortunately, that is
not the end of the story.
Various materials that protect interacting surfaces after the fluid film is
lost have been either
discovered or created. These materials may be applied to a surface in the
form of an additive to a fluid lubricant, or in a pure form, and may also be
added or alloyed into the surface when the component is being manufactured.

The more common types of materials include the following:

Molybdenum disulfide (MoS2) –also known as moly
Polytetrafluoroethylene (PTFE) – also known as Teflon®
Graphite
Boron nitride
Talc
Calcium fluoride
Cerium fluoride
Tungsten disulfide

These materials are characterized as dry film or solid film lubricants.
Moly, graphite and Teflon are the most commonly recognized by
practitioners of machinery lubrication. Molybdenum
and graphite are agents that are extracted from mined ore. Teflon
was created by DuPont Chemical Company and is manufactured by
various companies for many purposes.

Dry Film Lubrication
Dry film lubricants are solid materials that provide low frictional

resistance between surfaces when applied directly to interacting surfaces.
Each material has different properties. Crystalline lattice (lamella)

structure materials, such as molybdenum disulfide, tungsten disulfide

and graphite, are widely used as agents in lubricants and as stand-alone

lubricants. These materials are used independently or in combination with
other agents and metals (lead, copper) to achieve the desired results.
Lamella lubricating powders have low shear forces between their

crystalline
lattice layers that minimize resistance between sliding surfaces.

Figure 1. Crystal Structure of MoS2
(Reference: Dynamic Coating, Inc.)

As seen in Figure 1, these materials have structured layers that form

and interact against other structure layers.
Most dry lubrication film materials work well in dry environments and

are
excellent supplemental or boundary layer materials in fluid systems.

The long chain fluorocarbon molecules, such as polytetrafluoroethylene,

tend to have wetting angles that promote release and prevent sticking,

as well as a variety of other attractive
characteristics for high-temperature operation. This article addresses the
most frequently used dry film lubricating agents.

General Dry Lubricant Properties
Each dry lubricating material has different properties.
Molybdenum disulfide, graphite and tungsten disulfide are oilioscopic.

Their structure is unable to tolerate detergents. These layer lattice

lamella structures are analogous to stacks
of nonadherent plates which, with slight tangential loading, slip out of

place. It is comparable to walking across a room full of flat slippery plates.

The lamella materials have good load-bearing capacity in sliding and

rolling mode. Graphite has high-temperature capability and functions
well in radiation atmospheres. MoS2 and WS2 function well in hard

vacuum and tolerate higher
loads better than graphite.

Molybdenum Disulfide (MoS2)
Molybdenum was not discovered until the latter part of the 18th century,

and does not occur in the metallic form in nature. Despite this, its

predominant mineral - molybdenite - was used in ancient times

(a 14th-century Japanese sword has been found to contain molybdenum)

but would have been indistinguishable from other similar materials such

as lead, galena and graphite. Collectively, these substances were known

by the Greek word “molybdos”, which means lead-like.
Molybdenum was first positively identified in 1778 by a Swedish scientist,

Carl Wilhelm Scheele. Shortly thereafter, in 1782, Peter Jacob Hjelm

reduced molybdenite oxide with carbon to obtain a dark metallic powder

which he named “molybdenum”.
Molybdenum remained a laboratory curiosity throughout most of the 19th

century until the technology for the extraction of commercial quantities

became practical. In 1891, the French
company Schneider and Co. first used molybdenum as an alloying element

in the production of armor plates. It was quickly noted that molybdenum

was an effective replacement for tungsten in numerous steel alloying

applications because its density is only slightly more than half that of

tungsten.
MoS2 occurs naturally in the form of thin solid veins within granite. It

is mined and highly refined to achieve purity suitable for lubricants.

MoS2 has a hexagonal crystalline structure
as shown in Figure 1. The intrinsic property of easy shear occurs at the

interface between the sulfur molecules. The interaction between layers

provides an effect similar to what a person may experience if trying to

maneuver across a floor completely covered with brand new playing cards.
Each playing card slides easily with respect to each individual layer.

As the total surface resistance is reduced or redistributed among many

other interacting surfaces, the net effect is reduced total surface friction

and resistance.
Because there is no vapor present between lattice plates, MoS2 is

effective in high-vacuum conditions, where graphite will not work.

The particle size and film thickness are important
parameters that should be matched to the surface roughness of the

lubricated component. Particle size selection is much larger for rough

cut surfaces, such as hobbed open gears, than for highly finished surfaces,

such as those found on bearings. Improperly matched particle sizes may

result in excessive wear by abrasion caused by impurities in the MoS2.
The temperature limitation of MoS2 at 400°C (752°F) is imposed by

oxidation. MoS2 oxidizes slowly in atmospheres up to 600°F. In a dry,

oxygen-free atmosphere it can function as a lubricant up to 1300°F.

The oxidation products of MoS2 are molybdenum trioxide (MoO3)

and sulfur dioxide. MoS3 is hydroscopic and causes many of the friction

problems in standard atmosphere. MoO3 is a preferred form of the

metal used as an additive for various other metals, which is its primary

use.
The issue of where molybdenum disulfide should be used, versus graphite

or tungsten disulfide, is generally best addressed by a lubrication

engineer. For most commercial applications,
these are relatively simple judgments. In aerospace applications

where unique environments and exotic materials are employed,

these questions often take substantial research to provide the best answers.
The low friction coefficients of MoS2 often exceed that of graphite.

Graphite
Graphite as a lubricant dates to antiquity. It was first referenced in the

mid-1500s as being used as pencils. Graphite is a soft, crystalline form

of carbon. It is gray to black, opaque, has a metallic luster, and is flexible

but not elastic. Graphite occurs naturally in metamorphic rocks such as
marble, schist and gneiss. It exhibits the properties of a metal and a

nonmetal, which makes it suitable for many industrial applications.

The metallic properties include thermal and electrical conductivity.

The nonmetallic properties include inertness, high thermal resistance and
lubricity. Some of the major end uses of graphite are in high-temperature

lubricants, brushes for electrical motors, friction materials, and battery

and fuel cells.4
Graphite is a layer lattice lamella crystal structure where the bonds

between the carbon atoms in the crystal structure of the layer are stronger

than the carbon bonds between layers.
Graphite is comprised of carbon and water vapor. Each carbon atom is

bonded to three other surrounding carbon atoms. The flat rings of carbon

atoms are bonded into hexagonal structures, as shown in Figure 2.

The hexagonal carbon structure is referred to as a benzene ring.

These plates exist in layers, which are not covalently connected to the

surrounding layers.

Figure 2. Graphite
Lamella Lattice Structure
(Reference: Dynamic Coating, Inc.)

Graphite has excellent lubricating properties, as long as moisture vapor

is available, and will function as a lubricant up to approximately 1450°F,

and as a release and antiseize up to about 2400°F. The oxidation product

is CO2. Due to the requirement for entrained moisture vapor, graphite

does not function well as a lubricant in a hard vacuum and is therefore

seldom used in deep-space applications.
Graphite blends and pure graphite dry film lubricant systems are commonly

used in applications such as hot and cold forming, wire drawing and billet

coatings; on high-speed cutting tools; as a mold release for die cast, plastic

and rubber mold applications; cylinder head and exhaust bolts; ammunition

and armament applications; automotive engine and many common

industrial applications.

Figure 3. Graphite Ore

Figure 4. Teflon Molecular Structure

Long Chain Fluorocarbon - Teflon®
The linear long chain molecule “polytetrafluoroethylene”, was accidentally

discovered by Dr. Roy Plunkett on April 6, 1938, at DuPont’s Jackson

Laboratory in New Jersey. Plunkett was working with gases related to

Freon® refrigerants (also known as chlorofluorocarbons), another

DuPont product.
Upon checking a frozen, compressed sample of tetrafluoroethylene, he

discovered that the sample had polymerized spontaneously into a white,

waxy solid to form polytetrafluoroethylene (PTFE). The chemical formula

is [C2F4] N. PTFE is a saturated aliphatic fluorocarbon.

Figure 5

Figure 6

PTFE does not have mechanical occlusion characteristics similar to

graphite or molybdenum. In fact, Teflon itself resists wetting, and the

surfaces coated with these materials likewise resist wetting.

For surfaces to bond with PTFE and the variety of other long chain

fluorocarbons, it is necessary for them to be properly prepared through

surface roughing or pickling.
PTFE is inert to virtually all chemicals and is considered the most slippery

material in existence. The coefficient of static and dynamic friction is

nearly equal to the level of wet ice on wet ice. As DuPont registered

trademark Teflon®, it has become a household name associated with

its use as a coating on cookware and as a soil and stain repellant for

fabrics and textile products. It does not absorb water, and is unaffected

by acids, bases and solvents normal to industry at temperatures less

than 500°F.

Figure 7

Various fillers can be added to PTFE to enhance certain characteristics,

such as glass fiber (high wear resistance, good electrical, low friction),

graphite (low friction, excellent chemical resistance, high creep resistance),

carbon fiber (high wear resistance, high load resistance,

high bend resistance), glass fiber and molybdenum disulfide

(high wear resistance, low friction, high creep resistance), and bronze

(high wear resistance, heat dissipation). In some industries, such
as the bearing pad industry, filled PTFE has become the standard, where

various percentages of glass fiber are added to the base PTFE resin to

create an extremely tough, weatherproof, interface material that can be

cut or stamped into configurations to match the dimensions of the opposing

surfaces.7 PTFE is licensed to many manufacturing firms for a variety of

material types.
Solid film lubricants offer protection beyond the normal properties of

most mineral and synthetic oil-based fluid lubricants. Conditions that

warrant the use of these agents in a pure form,
or as an additive, include extremes of temperature, pressure, chemical

and environmental contamination. Some agents have a strong affinity

for metallic surfaces, and will adhere to those surfaces through loose

covalent forces. These may be applied directly as a topical coating or

indirectly in the form of an additive to a fluid lubricant. Some agents have

no natural attractiveness to metallic surfaces, and therefore must be

bonded to the surface through specialized treatment.
The solid lubricating materials tend to have upper temperature ranges

well above the surface-protecting capabilities of mineral and most

synthetic base stocks. Fluorinated hydrocarbons are stable in liquid or

solid form to roughly 600°F, but will begin to degrade and may produce

noxious fumes at that temperature.
Graphite and molybdenum can operate in a similar temperature range,

and molybdenum disulfide can also function in a vacuum without losing its

slippery property.