TPV-ExxonMobil Santoprene 101-55
Substituting vulcanized EPDM rubber in demanding automotive and industrial sealing environments without the processing limits of thermosets requires a specialized elastomer, which ExxonMobil’s Santoprene 101-55 (now Celanese) delivers through its chemically cross-linked EPDM rubber phases dispersed inside a continuous polypropylene matrix. Boasting a density of 0.97 g/cm³ and a soft hardness of 55 Shore A, this thermoplastic vulcanizate (TPV) provides outstanding compression set, ozone resistance, and low-temperature flexibility down to -60°C. Jucheng Precision, operating under strict ISO 9001 and IATF 16949 standards, specializes in precision injection molding of Santoprene 101-55. Utilizing in-house 5-axis CNC-machined S136 tool cavities, we optimize gate geometry to mitigate shear-induced flow lines, delivering dynamic seals verified by Zeiss CMM.
Santoprene 101-55 Chemical & Mechanical Resilience
Santoprene™ 101-55 is a fully vulcanized, black thermoplastic elastomer (TPV) compound engineered by ExxonMobil (now Celanese), designed to deliver exceptional rubber-like sealing performance under strict ASTM standards:
| Structural/Physical Parameter | Tested ASTM Spec Value | Dynamic Sealing Benefit |
|---|---|---|
| Shore Hardness | 55 Shore A (ISO 868) | Provides vulcanized-rubber flexibility and soft tactile feel, ensuring absolute sealing compliance and dynamic energy absorption. |
| Compression Set | Compression Set 38% (at 125°C, 70h) | Delivers outstanding elastic recovery under long-term thermal compression, ensuring zero leak in high-heat engine couplings. |
| Subzero Brittleness | Brittleness Temperature -60°C | Maintains exceptional mechanical toughness and elastic flexibility in extreme-freeze environments, avoiding brittle cracking. |
Severe Weathering Process Configurations for Santoprene 101-55
With its high-toughness elastomer matrix and non-halogen stability, Santoprene 101-55 processes reliably under advanced molding profiles:
| Molding Technology Class | Process Compatibility & Operational Details |
|---|---|
| Automotive Sealing Gaskets | Excellent. Fully optimized for automotive window seals, glass run channels, engine air intake gaskets, and low-temperature sealing boots. |
| Heavy-Duty Dust Bellows | Excellent. High tear resistance and dynamic fatigue life are perfect for molding steering rack boots, CV joint bellows, and expansion joints. |
| Overmolding & Co-Injection | Excellent. Co-injects with rigid Polypropylene (PP) substrates in 2K setups, ensuring a permanent chemical weld line without peeling. |
Molding Analysis: Santoprene 101-55 Tooling & Volumetric Shrinkage Guide
Molding a highly shear-thinning thermoplastic vulcanizate like Santoprene 101-55 requires precise gate planning to manage high shrinkage and prevent flow lines:
Shear-Thinning Gate Design (Anti-Flow Line)
TPVs are non-Newtonian; melt viscosity drops drastically under high shear rates. Jucheng’s tooling division uses 5-axis CNC machines to cut generous gate channels and wide runners (minimum 60% of part thickness). This reduces gate shear and prevents visible flow line and splay defects on matte surfaces.
Managing High Anisotropic Shrinkage
Santoprene 101-55 exhibits high and anisotropic shrinkage (typically 1.50% to 2.50%). We employ Moldflow simulation during our free DFM review to balance gate locations, aligning EPDM rubber particles uniformly to prevent component warping and out-of-tolerance dimensions.
Mold Temperature Matrix (Cooling Control)
We maintain mold temperatures at 20°C–50°C (68°F to 122°F) using pressurized water chillers. Keeping tools cold is critical to freeze the soft EPDM phase quickly, allowing for automatic, warp-free ejection. Melt temperatures are controlled at 180°C–220°C (356°F–428°F).
Desiccant Drying & Volatiles Exhaust
We dry raw resin in desiccant hopper dryers at 80°C (176°F) for 3 hours. This eliminates surface splay and prevents weld-line micro-voids, keeping internal moisture strictly below 0.08%. Precise venting slots (0.015mm depth) are cut along parting lines to exhaust gas during high-melt runs.
Key Application Fields for TPV-ExxonMobil Santoprene 101-55
- Automotive Under-the-Hood & Seals (IATF 16949): High-pressure engine air ducts, windshield wiper seal profiles, window guide run channels, rack-and-pinion boots, and suspension bellows.
- Industrial plumbing & Fluid Systems: Potable water mixing valve seals, dynamic chemical pump diaphragms, flexible water seals, and high-pressure pipe gaskets.
- Medical Diagnostics & Food Contact (ISO 13485 Compliant): FDA-approved medical-grade peristaltic pump tubing connector seals, cosmetic container caps, and hospital sterilizer door gaskets.
Properties
| Density | 0.97 g/cm³ |
| Hardness (Shore A, 15s) | 55 - |
| Tensile Strength (Ultimate, Break) | 4.4 MPa |
| Tensile Elongation at Break | 380 % |
| Tear Strength | 16 kN/m |
| Compression Set (125°C, 70h) | 38 % |
| Compression Set (70°C, 24h) | 27 % |
| Compression Set (23°C, 168h) | 22 % |
| Flammability Rating | UL 94 HB Class |
| Drying Temperature | 80 °C |
| Drying Time | 3 hr |
| Rear / Middle / Front Barrel Temperature | 180 / 200 / 220 °C |
| Mold Temperature Range | 20 - 50 °C |
| Low Temperature Brittleness | -60.0 °C |
| Linear Mold Shrinkage | 1.5 - 2.5 % |
| Maximum Part Size | 800 x 600 mm |
| Minimum Part Size | 1 x 1 mm |