TPE & TPU Injection Molding Materials (Elastomers)
Thermoplastic Elastomers (TPE) and Thermoplastic Polyurethanes (TPU) are unique materials that combine the processing ease of plastics with the flexibility and durability of rubber. Unlike thermoset rubber (which takes minutes to cure), these materials can be molded in seconds, making them ideal for high-volume production. At JUCHENG, we are experts in processing elastomeric resins. We specialize in Two-Shot (2K) Molding and Insert Overmolding, bonding soft TPE/TPU layers onto rigid substrates to create ergonomic grips, watertight seals, and impact-resistant bumpers for the power tool, medical, and consumer electronics industries.
TPE & TPU Injection Molding Materials (Elastomers)
JUCHENG's Elastomer Molding Capabilities
Molding soft plastics requires precise control over pressure and temperature to prevent flash and ensure adhesion. JUCHENG delivers:
- Overmolding Expertise: We master the art of chemical bonding between soft and hard plastics. We help you select the right TPE grade to bond naturally with your specific ABS, PC, or PP substrate without primers.
- Hardness Customization: We stock elastomers ranging from ultra-soft Shore 30A (gel-like) to semi-rigid Shore 90A (hard rubber heel), allowing for precise tactile tuning.
- Two-Shot Molding: For high-volume projects, we utilize rotary platen machines to mold the hard substrate and soft skin in a single cycle, ensuring perfect alignment and cycle time reduction.
- Surface Texturing: We apply specialized mold textures (VDI/Etching) to TPE parts to enhance grip and eliminate the "sticky" feel often associated with glossy soft plastics.
Detailed Material Profiles
We offer two primary families of thermoplastic elastomers:
1、TPU (Thermoplastic Polyurethane)
- Description: A tough, durable elastomer known for its outstanding abrasion resistance and mechanical strength. It bridges the gap between rubber and hard engineering plastics.
- Key Advantages: Excellent wear/scratch resistance, high load-bearing capacity, good resistance to oils and greases, high transparency grades available.
- Applications idéales: Industrial casters/wheels, heavy-duty phone cases, footwear outsoles, drive belts, seals exposed to oil.
- Description: A broad family of materials (often Styrenic block copolymers like TPS). It offers a softer, more rubber-like feel than TPU and is easier to process.
- Key Advantages: Superior "Soft-Touch" tactile feel, excellent colorability, lower cost, good elongation. Food-safe and medical grades widely available.
- Applications idéales: Toothbrush grips, power tool handles, buttons, sealing gaskets, baby products, medical syringe plungers.
Overmolding Compatibility Chart
Selecting the right elastomer is critical for chemical bonding. Not all soft plastics stick to all hard plastics:
| Substrate (Hard Plastic) | Recommended Elastomer | Bonding Quality |
| PP (Polypropylene) | TPE (Olefin-based) | Excellent (Chemical Bond) |
| PE (Polyethylene) | TPE (Olefin-based) | Good |
| ABS / PC / PC-ABS | TPU or Specialized TPE-S | Excellent (Chemical Bond) |
| PA (Nylon) | Specialized Modified TPE/TPU | Difficult (Requires mechanical interlock or specialized grades) |
| Metal (Steel/Al) | TPU / TPE | Mechanical Bond Only (Requires holes/undercuts in metal) |
Design Guidelines for TPE/TPU
- Mechanical Interlocks: Even with chemical bonding, we recommend designing holes, grooves, or undercuts in the hard substrate to mechanically lock the soft material in place.
- Wall Thickness: TPE cools slowly. Keep walls uniform. Thin sections of TPE over a hard substrate should be at least 0.8mm - 1.0mm to prevent flow lines or tearing.
- Shut-Offs: Design clear shut-off boundaries where the soft material meets the hard material to prevent flash (thin leakage) on the cosmetic surface.
- Shrinkage: Elastomers have high and variable shrinkage (1.0% - 3.0%). Tooling must be tuned to the specific grade used.
Application Scenarios
- Consumer Goods: Soft-grip handles for toothbrushes, razors, and kitchen utensils (TPE over PP).
- Electronics: Rugged protective cases for tablets/phones (TPU over PC), waterproof gaskets.
- Automobile: Interior mats, cup holder liners, window seals, HVAC vibration dampers.
- Industrial: Power tool grips (vibration damping), flexible bellows, wire strain reliefs.
Comprehensive Comparison Table
Physical properties comparison of TPU vs. TPE:
| Property | TPU (Polyurethane) | TPE (Styrenic/Olefinic) | Unit |
| Hardness Range | 60A - 80D (Harder) | 0A - 90A (Softer) | Shore |
| Abrasion Resistance | Excellent | Moderate | - |
| Tactile Feel | smooth, plastic-like | Rubbery, grippy | - |
| Chemical Resistance | Good (Oils/Fuels) | Moderate (Acids/Bases) | - |
| Compression Set | Good | Fair | - |
| Cost | Medium/High | Low/Medium | - |
FAQ: Elastomers
- Q: Can TPE be painted?
- Q: What is the difference between Silicone and TPE?
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ㆍConfidentialité : Nous respectons votre vie privée. Vous trouverez ici un exemple d' accord de non-divulgation. En soumettant ce formulaire, vous acceptez nos conditions générales et notre politique de confidentialité.

