PARC Events

Filament Extension Atomizer: Novel Aerosol Generation from Polymer Melts and Applications in Additive Manufacturing

Sun, 28 Oct 2018 00:00:00 -0700

October 28, 2018 |

PARC, A Xerox Company is developing a novel approach to aerosol generation called Filament Extension Atomization (FEA). FEA is a method that can generate droplets from highly viscoelastic, strain hardening fluids such as molten thermoplastics. FEA-generated droplets from these molten polymers can be narrowly-dispersed and could enable multiple disruptive advances in additive manufacturing. PARC aims to develop this key platform technology into multiple use cases in view of additive manufacturing including 1. particle creation for selective laser sintering; 2. direct ionographic printing of 3D objects and 3. digital deposition of coatings. In particular, since FEA can generate droplets from virtually any thermoplastic regardless of resin type or material grade, PARC FEA has the potential to disrupt polymer-based additive manufacturing by increasing the range of materials that can be used in either existing or new methods. Preliminary data on our research efforts on these use cases will be discussed in this contribution.

Filament Extension Atomizer: Novel Aerosol Generation from Viscous Fluids and Applications in Biotechnology

Sun, 28 Oct 2018 00:00:00 -0700

October 28, 2018 |

PARC, A Xerox Company is developing a novel approach to aerosol generation from high viscosity fluids called Filament Extension Atomization (FEA). The method is specifically suited for spraying highly viscoelastic, strain hardening fluids such polymers and biomacromolecules which are often difficult to spray using conventional methods that are viscosity-limited. The FEA approach employs the intrinsic elastocapillary instability in these strain hardening fluids to generate narrowly-dispersed micron-sized droplets of the fluid that can used for various applications. FEA can generate spray from a wide range of fluids with viscosities ranging from 1mPa-s up to 600 Pa-s and higher. In this contribution, we will highlight its potential applications in biotechnology, specifically in the controlled aerosol delivery of bioactives and in particle creation from viscous formulations.

The Role of End-Plate Wetting in the Filament Formation and Break-up of High Surface Tension, Strain Hardening Fluids

Sun, 28 Oct 2018 00:00:00 -0700

October 28, 2018 |

We investigated the effects of end-plate wetting on the filament formation and thinning leading to break-up of a high surface tension, strain hardening polymer solution – a 30% hydrolyzed poly(acrylamide-co-acrylate) in water. For the low aspect ratios and small volumes of fluid that we investigated, we found a dramatic effect of different end-plate combinations ranging from strongly wetting to strongly non-wetting on various aspects of filament formation and break-up. For some end-plate combinations, the final volume transfer to the top plate is strongly affected by both fluid volume and the imposed rate of plate displacement which we rationalize based on the work of adhesion. For cases where the top end-plate is non-wetting, we observed highly shortened filament thinning profiles accompanied by significantly lower apparent relaxation times. We fit the time evolution of the filament diameter with an empirical expression with a time-dependent effective relaxation time, much different from the classic single exponential expression from Entov and Hinch. We will discuss the implications of our findings in the context of roll-to-roll processes on viscoelastic solutions involving rollers with different materials.

Next-Generation Aerosol Technology for Viscoelastic Fluids: Filament Extension Atomization

Sun, 14 Oct 2018 00:00:00 -0700

October 14, 2018 |

PARC is developing a next-generation aerosol technology that can generate droplets (mist) from viscoelastic fluids based on a roll-to-roll process that heavily involves fluid extension. While conventional spray methods tend to be viscosity-limited and do not perform reliably for strain hardening fluids, PARC’s technology called Filament Extension Atomization TM (FEA) can generate high-quality narrowly-dispersed micron-sized droplets exactly from these strain hardening fluids. These could range from polymer solutions, polymer melts and other systems that exhibit extensional hardening. In this contribution, we will present a systematic mapping of the spray quality (particle size distribution, particle velocity distribution) generated by FEA as determined by processing parameters from a series of strain hardening polymer solutions with concentrations spanning the dilute, semi-dilute and concentrated regimes. We will discuss the role of strain hardening and fluid extensional behavior on spray processing through FEA and in the resulting spray quality. Some compelling use cases in additive manufacturing and in biomedical and biotechnological applications will also be discussed.

Multi-material Printing for 3D Electronics

Tue, 28 Aug 2018 00:00:00 -0700

August 28, 2018 |

The abstract is the paper. This is an invited talk.