Injection molding Santoprene™TPVs
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When injection molding Santoprene™ TPVs , the polymer is first introduced into a heated barrel and screw. Once sufficiently softened, the melted polymer is injected into a closed mold under high pressure. After allowing sufficient time for the molten polymer to cool, the finished part can be removed from the mold. Since Santoprene TPVs combine the processability of a thermoplastic with the performance characteristics of thermoset rubber, they allow efficient processing of any grade using thermoplastic injection-molding equipment.
Injection mold processing tips for Santoprene TPV
- Completely purge all PVC or acetal resin from the machine before or after running Santoprene TPVs.
- Cooling time depends on wall thickness, grade and tool design. Cushion size is typically 3 to 6 mm (0.125" to 0.250").
- Hold time is typically 3 to 4 seconds, and hold pressure is approximately 50% of injection pressure.
- It is far more effective to increase shear rate than to raise melt temperature for filling a mold.
- Injection rate should be 10 to 50 g/sec.
- Injection speed should be medium (50%) to maximum (100%) of machine capacity.
- Injection times range from 0.5 to 2.5 seconds in order to optimize shear.
- Regrind can be used. Consistent regrind ratios are recommended to minimize process variations.
- Pre-drying the material is recommended at 82°C (180°F) – 3 hours for virgin material and 4 hours for reground material.