TPU Injection Molding
We mold TPU (and compatible grades) for functional, structural and aesthetic parts — from low-volume bridge production to high-volume runs.
Broad Hardness Range
TPU from 60 Shore A to 75 Shore D — soft-touch overmolds, flexible gaskets and stiff structural carriers from the same material family.
Abrasion & Tear Resistance
Polyurethane’s signature toughness — parts that survive flexing, scraping and impact where standard elastomers wear out.
Overmolding & Insert Molding
TPU bonded over rigid plastics or metal inserts on vertical and horizontal presses for soft-touch handles, bumpers and sealed assemblies.
Controlled Drying & Processing
TPU is hygroscopic — we dry and process per grade spec so voids, streaks and property loss never reach the part.
Consistent Durometer Verification
Hardness and dimensions verified on first articles and in-process, with reports per batch.
What TPU Brings to a Molded Part
Thermoplastic polyurethane (TPU) sits between rubber and rigid plastic: it flexes and absorbs impact like an elastomer, but processes on standard injection machines like a thermoplastic. That combination buys three things in a part — abrasion resistance (wheels, rollers, cable jackets), flex fatigue life (bellows, straps, hinges) and soft-touch feel (grips, handles, wearable housings). Hardness spans roughly 60 Shore A to 75 Shore D, so one material family covers everything from a gasket to a structural carrier.
TPU also pairs well with rigid substrates. We overmold TPU onto PC, ABS, nylon and PBT carriers, and insert-mold around metal, which is how phone cases, power-tool grips, caster wheels and sealed connectors are made. For a full process walkthrough, see our TPU material page and the TPU injection molding guide.
Applications & Material Selection
- Industrial & automotive: seals, bumpers, bellows, cable glands, wear pads and anti-vibration mounts that face oil, weather and abrasion.
- Consumer & wearable: soft-touch overmolds, watch straps, phone cases, footwear components and appliance feet.
- Medical-adjacent: tubing fittings, grips and flexible components — processable under our ISO 13485-aligned systems with documented material certs.
- Grade selection: ester-based TPU for toughness and oil resistance, ether-based for hydrolysis and low-temperature flex — we confirm the right base chemistry in DFM rather than guessing.
Material choice drives both performance and moldability. Polyester TPU is tougher but hydrolyzes in hot humid environments; polyether TPU survives moisture and cold flex but costs more. Fillers, flame retardants and food-contact grades shift the balance again. Our engineers lay out the trade-offs in writing before tooling, and every lot is verified against its material certificate.
Processing TPU Right
TPU is hygroscopic — it absorbs moisture from the air, and moisture is what turns a good part into a bad one: splay, voids and lost mechanical properties. We dry TPU per grade spec before molding, control melt temperature tightly (TPU degrades close to its processing window), and tune gate and vent design because TPU is viscous when cold and thin when hot. Durometer and dimensions are verified on first articles and sampled in-process, with batch reports on request.
For a market benchmark, First Mold advertises 100+ supported materials and ±0.01 mm injection molding tolerance (firstmold.com); our own tolerance commitments are written into the DFM and confirmed on the first article — quote us the same part and compare.
Frequently Asked Questions
What hardness range can you mold in TPU?
Roughly 60 Shore A to 75 Shore D, depending on grade. We confirm the target durometer in DFM and verify it on first articles.
Can TPU be overmolded onto rigid plastic?
Yes — TPU over PC, ABS, nylon and PBT is a standard soft-touch application for us, with adhesion validated per material pairing before production.
Is TPU suitable for outdoor or wet environments?
Ether-based TPU resists hydrolysis and low-temperature flex, making it the usual choice for wet or outdoor service; we select the base chemistry per application.
What are typical TPU lead times?
Soft-tooled low-volume runs ship in 7–12 days; production programs in 25–30 days once the tool is released.
What tolerances can you hold on TPU parts?
Molded tolerances follow the drawing and are verified on CMM/vision equipment; soft, thin-wall features are assessed in DFM since elastomers relax differently than rigid plastics.