VTR-9217 is a developmental precompound based on a recently developed 69% fluorine ‘B' type fluoroelastomer. This precompound incorporates a bishpenol cure system that can be optionally compounded with peroxide and coagent for ‘dual curing.' Superior thin extrusions for fuel and filler neck hose can be achieved. VTR-9217 has a unique combination of processing and cure characteristics including:

• high quality, smooth extrudate surface and appearance at thickness below .040" or 1.0 mm

• excellent ‘green' strength that helps maintain extrudate shape as well as enables draw down to a thickness of .008" or 0.2 mm.

• lower viscosity, lower hardness, and better compression set than VTR-9209, the first generation precompound based on the same gum polymer

• good fuel permeation resistance for a ‘B' type FKM

• compounds show good adhesion and physical properties

Automotive and small engine applications utilizing low permeation fuel and filler neck hose and tubing are expected to find this product most attractive as an affordable material. This product is superior in extrusion processability compared to Viton® B202 and B600 blends and VTR-7419 hose precompound.

Carnauba wax or VPA2 at a 1 to 1.5 phr level are the most common process aids used with VTR-9217 to create a smooth finish and good metal release. Combinations of these process aids with Struktol® WS280 can enhance release to some compounds.