Polymer Processing Aids deliver clear benefits
By Leah Mulcahey, Global Product Manager, Viton® FreeFlow™
DuPont™ Viton® FreeFlow™ polymer processing aids offers users a win/win scenario. They help improve the visual appeal of plastic films and also aid processing by reducing friction and shear stresses, thus eliminating melt fracture and reducing polymer build-up at the die exit.
With the use of polyethylene film growing year over year—especially in the food industry due to increased demand coupled with population migration patterns—aesthetics and processing efficiency are becoming more vital. Leading food brands have to ensure that their products are presented as visually appealing as possible, while striving for more efficient manufacturing operations.
Viton® FreeFlow™ from DuPont was developed predominantly to improve the processing of polyolefin polymers, such as linear low-density polyethylene (LLDPE) and high-density polyethylene (HDPE), including single-site technology polyethylene type polymers. However, it can perform well in a variety of other non-polar type polymers and blends. In addition to eliminating melt fracture and improving processability, Viton® FreeFlow™ polymer processing aids may also help lower operating costs, increase output, improve gauge control, increase melt strength, improve bubble stability and reduce the need for blending.
Viton® FreeFlow™ can also be used in conjunction with single-site technology type polymers (i.e., metallocene PE resins) yielding significant performance improvements during processing. Based on research laboratory results conducted by DuPont, resins incorporating Viton® FreeFlow™ polymer processing aids were processed with a 25°C lower melt temperature with the same die pressure. This translates to higher melt strength and faster cooling for optimal processing conditions.
Viton® FreeFlow™ polymer processing aids work on the basis of improving extrusion processes by coating the inside of the extruder barrel and die with a microscopically thin, non-stick film. The coating reduces friction between the processing polymer and metal surface within the extruder barrel/die, allowing the extrusion to flow freely and more rapidly through the die opening. These non-stick properties also prevent the accumulation of polymer build-up during extrusion at the die exit, referred to in the industry as die build-up (DBU).
Viton® FreeFlow™ polymer processing aids have undergone constant development since their launch, with products in the most recently launched Z Technology™ family significantly outperforming conventional polymer processing aids. Our latest Z Technology™ family, which takes advantage of proprietary technology developed within DuPont, offers greater performance and outstanding efficiency at a much lower usage level—typically 30%-50% less versus other competing polymer processing aids. As well as a more aesthetically appealing end product, less die build-up leads to lower scrap levels, which ultimately translates to greater cost savings.
DuPont will continue to develop and grow the Viton® FreeFlow™ polymer processing aid family of products by researching improved rheology using Viton® fluoroelastomers, effective interfacial agents and the delivery of optimal particle size to the die wall. This will provide new opportunities for multiple benefits to the end-users through further improvements in performance and greater flexibility in processing over a broader range of extrusion conditions.
Viton® FreeFlow™ polymer processing aids are supplied in granular powder form packaged in standard 20 kg bags/sacks. Contact your DuPont representative if your feeding systems require pellets or other packaging options.