TPU-Covestro Desmopan 385S
Combining the extreme mechanical strength of polyester-based polyurethanes with the outstanding hydrolytic stability of polyethers requires a specialized molecular architecture, which Covestro’s Desmopan 385S (belonging to the premium 300 Series) delivers. Boasting a density of 1.20 g/cm³ and a hardness of 85 Shore A, this hydrolysis-stabilized ester grade provides an ultimate tensile strength of 50.5 MPa and extreme DIN abrasion resistance (30 mm³ loss). Jucheng Precision, operating under ISO 9001 and IATF 16949 certified quality systems, specializes in precision molding of Desmopan 385S. Using S136 stainless steel molds polished on 5-axis CNCs, we control its complex 1.0% to 2.0% elastic shrinkage, ensuring zero-defect dynamic seal components verified by Zeiss CMM.
Desmopan 385S Structural Performance & Mechanical Resistance Profile
Desmopan® 385S belongs to the elite 300 Series of thermoplastic polyurethanes engineered by Covestro, certified to deliver maximum tensile strength, hydrolysis stabilization, and superior rebound resilience under ISO standards:
| Physical & Strength Parameter | Desmopan 385S Spec Values | Molding & End-Use Advantage |
|---|---|---|
| Tensile Ultimate Strength | Ultimate Tensile Strength 50.5 MPa | Exhibits extremely high mechanical tensile limit compared to standard TPU (typically 30-35 MPa), preventing structural deformation under extreme tension. |
| Abrasion & Tear Resistance | DIN Loss 30 mm³ / Tear 70 kN/m | Delivers outstanding mechanical wear protection and tear resistance, preventing crack propagation in dynamic structural parts and screenpacks. |
| Dynamic Recovery | Rebound Resilience 42% | High dynamic elastomeric spring-back properties prevent deformation, securing long-term sealing repeatability in dynamic industrial gaskets. |
Technical & Fluidic Process Configurations for Hydrolysis-Stabilized Desmopan 385S
With its high-strength block copolymer matrix and hydrolysis stabilization, Desmopan 385S processes reliably inside high-heat systems:
| Molding Technology Class | Process Compatibility & Operational Details |
|---|---|
| Hydrolysis-Stabilized Technical Parts | Excellent. Fully optimized for high-temperature water mixer valves, fuel caps, water meter connectors, and municipal hot-water plumbing pipes. |
| High-Strength Screenpacks & Hoses | Excellent. Low chemical swelling under high humidity. Ideal for heavy-duty industrial hoses, screenpacks, and fluidic gaskets. |
| Dynamic Low-Wear Industrial Seals | Excellent. Low compression set (30% at 23°C) and outstanding DIN wear resistance are perfect for hydraulic gaskets and dynamic seals. |
TPU-Covestro Desmopan 385S Tooling & High-Strength Molding Blueprint
Molding an amorphous high-strength polymer like Desmopan 385S requires strict thermal boundaries and low-stress mold setups to prevent flashing:
Micron-Level Flash Control (Tooling Precision)
Because Desmopan 385S exhibits exceptional fluidity under high shear, the molten resin can seep easily into minor mold gaps, causing parting line flash. Jucheng’s tooling division uses 5-axis CNC machines to achieve micro-tolerances, keeping mold parting clearances strictly within 0.005mm on premium S136 stainless steel mold cavity blocks hardened to 48-52 HRC.
Rigorous Pre-Drying Protocol
Wet polyester-based TPU experiences severe hydrolytic chain cleavage at high melt temperatures, destroying its high impact strength and causing surface splay. We pre-dry the raw resin in desiccant hopper dryers at 70°C–110°C (158°F to 230°F) for 1–2 hours, keeping moisture strictly below 0.05% before molding.
Key Application Fields for TPU-Covestro Desmopan 385S
- Industrial Infrastructure & Machinery: High-pressure industrial hydraulic gaskets, screenpacks, dynamic oil seals, dynamic expansion plugs, and protective sleeves.
- Automotive Powertrains & Chassis (IATF 16949): High-temperature dust bellows, steering rack protective sleeves, vibration-damping grommets, and chassis seals.
- Potable Water & Food Contact Systems: Faucet mixing valve seals, water meter connection rings, domestic water piping gaskets, chemical-resistant hoses, and couplers.
Properties
| Density | 1.2 g/cm³ |
| Hardness (Shore A, 15s) | 85 - 86 - |
| Hardness (Shore D, 15s) | 32 - |
| Ultimate Tensile Strength | 50.5 MPa |
| Tensile Elongation at Break (DAM) | 583 % |
| Tensile Stress at 100% Elongation | 5.7 MPa |
| Tensile Stress at 300% Elongation | 15 MPa |
| Tear Strength (Propagation, ISO 34-1) | 70 kN/m |
| DIN Abrasion Resistance (Loss) | 30 mm³ |
| Rebound Resilience | 43 % |
| Compression Set (23°C, 72h) | 30 % |
| Compression Set (70°C, 24h, Method C) | 25 % |
| Linear Mold Shrinkage | 1.0 - 2.0 % |
| Maximum Part Size | 800 x 600 mm |
| Minimum Part Size | 1 x 1 mm |