Improved Processibility, Higher Quality Products

Viton® FreeFlow™ is a unique family of additives that can solve many of the processing problems inherent in today's thermoplastics, especially polyolefins. Problems that result in poor product appearance and reduced throughput are solved by adding Viton® FreeFlow™. Processors also gain flexibility in operating parameters, enabling the use of new materials and new uses of existing equipment. By solving processing problems and providing operating flexibility, Viton® FreeFlow™ improves profitability and product quality.

During processing, many resins drag along the die surface. This drag is the source of many processing problems, including sharkskin melt fractures. Viton® FreeFlow™ coats the inner surface of the die with a fluoropolymer layer. The resin now slides on the fluoropolymer instead of dragging. Without drag at the die wall, the resin processes more easily. The primary benefit for any resin is increased flexibility of processing conditions. Instead of having machine conditions dictated by processing concerns, the processor now has more control. One can modify the temperature profile or other extrusion parameters to better optimize a specific process.

Viton® FreeFlow™ shifts the processing point at which sharkskin melt fracture begins. This allows production of smooth, clear fracture-free film at higher production rates in all types of equipment. Viton® will reduce or eliminate die build-up and unlike some other processing additives, Viton® FreeFlow™ will not affect the extruder pumping efficiency or the surface properties of film, such as seal strength and printability.

Below, sharkskin melt fracture causes the blown film to appear translucent in the photograph on the left. The same resin containing a fluoropolymer processing additive is shown on the right. With melt fracture eliminated, the film is now transparent.

Without Viton® FreeFlow™ film is melt-fractured. With Viton® FreeFlow™ film is fracture-free.

This same fluoropolymer type additive can be used to reduce die build-up. As the resin is extruded, the fluoropolymer will build a coating around the die exit. This coating will prevent other material from adhering to form die build-up. The pictures below show a tubing line running with and without a fluoropolymer additive. In the picture on the left, die build-up can be seen as dark thread-like material extending from the die. In the other picture, a properly chosen fluoropolymer has been used to reduce the die build-up. Both pictures were taken after approximately one hour of extrusion.

Without Viton® FreeFlow™ die build-up is excessive. With Viton® FreeFlow™ die build-up is reduced.