Extruding Santoprene™ TPVs

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Santoprene TPVs extrude easily into single and complex profiles. They have very good melt strength and exhibit low die swell.

Santoprene TPVs can be co-extruded to yield a part with both rigid and soft components. ExxonMobil has also developed both chemical and patented water-foaming technology to improve profile flexibility and reduce part weight.

Download our extrusion guidelines and discover how easy Santoprene TPV is to extrude into single and complex profiles to yield rigid and soft components.

Tips for extruding Santoprene TPVs

  1. Pre-dry ALL material for 3 to 4 hours at 82°C (180°F).
  2. To reduce viscosity in the extrusion process, it is more effective to increase RPM than to increase temperature.
  3. Extruder/screw recommendations:
    1. Minimum L/D of 24:1
    2. Screw compression ratio of 2.5 to 3.1
    3. Use Barrier or Maddock mixer screw.
    4. Contact the AnswerPersonSM for foamed extrusion applications.
  4. Size extruder depending on cross-sectional area. Extruder range 30-80 RPM to optimize extrudate quality.
  5. Die design recommendations:
    1. Keep land length to a minimum (never exceed 16 mm [0.625 in]).
    2. Streamline flow channels in the head and die.
    3. Oversize die opening by 7 to 10% for length and width depending on material hardness.
    4. Oversize die opening by 3 to 5% for thickness depending on material hardness.
  6. Do not exceed 15% drawdown.
  7. Run with lowest melt-temperature possible (do NOT exceed 215°C [420°F]).
  8. Use consistent regrind ratio (recommend 20% regrind to 80% virgin).
  9. Use PP- or PE-based carrier for color concentrates.
  10. Do NOT use PVC or acetal in the extruder before or after running Santoprene TPVs.

Innovative robotic extrusion technology developed by ExxonMobil and GEPOC Verfahrenstechnik GmbH in Germany is an effective solution for producing multifunctional rigid/soft part combinations with Santoprene TPV as the soft sealing component.

While the injection molding process is widely used for the production of hard/soft material combinations, it is difficult to produce large, complex or hollow soft profiles, especially on larger parts. Robotic extrusion technology is one option to overcome these difficulties, enabling soft profiles to be extruded onto or around rigid substrates. Adhesion to the substrate is achieved using mechanical fixation, a bonding agent or, in the case of a polypropylene substrate, heat welding.