Rubber-like elastic recovery, gasket-and-seal hardness, printable from CAD without moulding tooling · cross-checked against the manufacturer's TPU95 TDS V5.1, written by the team that prints it.
TPU flexible 3D printing service · UK · quoted in 6 hours.
Stretches 330% and springs back. Different mechanical regime to rigid filaments.
Four quick visuals. Start with which material to pick and where TPU works; the engineering detail is at the end if you want it.
Rigid urethane "hard" segments crystallise into physical cross-links at room temperature; flexible polyol "soft" segments contribute elasticity. The two phases phase-separate at the nanometre scale · this is what makes TPU both 3D-printable (melt the hard segments at 200°C) and elastomeric (springs back from large strains).
TPU95 elongation at break is 330% (ISO 37 · rubber tensile) · two orders of magnitude more than rigid filaments. The 100% modulus is 9.4 MPa (stress required to stretch the specimen to 2× its length). Rigid filaments like PETG (8.4%) and PLA (6.3%) break before they stretch a tenth as far. Different mechanical regime, not a softer version of the same family.
"James handled the 3D printing for a functional heat resistant component we needed in batch production. He helped dial in the prototype first with their design service, then produced the final batch with really consistent results. Super fast 3D print turnaround and great quality across all the 3D printed parts. Will 100% be coming back."
"We needed a sit-in F1-car for an exhibition to showcase our new racing game. 3D Printing Express took our CAD, optimised it for strength and weight as we had no idea how it all worked! Turned out beautifully. They colour matched the finish and was looking like the real deal. On show day the cockpit ran non-stop, adults and kids jumped in. Multiple visitors asked who built it."
"We ordered a batch of 100 PA-12 parts from 3D Printing Express and could not be happier. Every part arrived consistent, dimensionally accurate, and ready for use straight from the box. The PA-12 gave us the strength and stability we needed for functional testing, with minimal post-processing required. Delivery was on time, communication was excellent, and their QC clearly made a difference."
Industrial-standard flexible-service hardness · same as commercial moulded gaskets and phone-case inserts. Firm-but-compliant feel. Shore 90A on request for softer, more rubber-band-like service.
The stress required to stretch the specimen to 2× its length · the rubber-tensile counterpart to "tensile strength" for rigid plastics. Two orders of magnitude lower than rigid filaments · TPU deflects under load that rigid plastics shrug off.
Stretches 3× its original length before failure · the headline TPU metric. Rigid filaments break at 3-10% (PETG 8.4%, PLA 6.3%). Different mechanical regime, not a softer version.
Hygroscopic · higher than rigid filaments because the segmented urethane matrix absorbs more. We dry every spool at 65-70°C for 4-6 hours before printing. Wet TPU prints with surface bubbles, stringy extrusion, and reduced layer adhesion.
TPU earns its place when a part needs to deflect by tens or hundreds of percent and spring back · the flexible engineering polymer for gaskets, seals, shock absorbers, and soft-touch surfaces. Shore 95A hardness, 330% elongation at break, no moulding tooling cost.
TPU's superpower is elastic recovery from large strains · its weaknesses are sustained-load creep, viscoelastic hysteresis at high cycle rate, broad chemical sensitivity, and a service ceiling around 80°C. Pick a different filament if any of these apply.
Shore 95A is the same hardness as the majority of commercial moulded gaskets. The flexible matrix compresses 20% and recovers · prints from CAD without injection-mould tooling. Oil and grease resistant. Right pick for short-run or one-off seals where moulding cost can't be justified.
The rubber-like matrix absorbs impact energy by deflecting rather than cracking. Drone landing gear cushions, robotic-arm impact pads, fixture end-stops, drop-test foot cushions · TPU bends and recovers where rigid filaments fracture. Direct CAD-to-part, no tooling lead time.
TPU's viscoelastic matrix damps vibration that would otherwise transmit through rigid filaments. Machine-foot mounts, panel-mount sensor isolators, drum-and-fan vibration dampers, instrument-rack feet · prints in any geometry needed to fit the panel cutout or chassis pocket.
Shore 95A matches commercial phone-case and ergonomic-grip hardness · soft to hold, grippy on glass and painted surfaces, won't damage delicate parts. Used for custom phone cases for odd or discontinued devices, ergonomic tool overgrips, robotic gripper jaws that hold without crushing.
TPU is the flexible engineering polymer · rigid filaments and silicone are the two adjacent options engineers compare when picking it. TPU wins for low-volume flexible parts where moulding cost is not justified. Rigid filaments win for load-bearing structure. Silicone wins for extreme-temperature or chemical-service flexible parts (but needs injection-mould tooling).
TPU95 values from TDS V5.1 EN (ISO 37 rubber tensile, ISO 7619-1 Shore hardness). TPU90 values from TPU90 TDS. Silicone values from industry literature for general moulded silicone. Each material wins on one axis · TPU95 on cost/lead-time (no tooling, days not weeks), TPU90 on elongation (softer, more rubber-band-like), silicone on temperature range and chemical resistance. Pick TPU when the volume doesn't justify silicone tooling.
| Property | TPU95 (here) | TPU90 (softer) | Silicone (moulded) | Rigid filament (PETG / PA12-CF) |
|---|---|---|---|---|
| Shore hardness | 95A · industrial-standard gasket hardness | 90A · softer, more rubber-band-like | 20A-80A typical | Shore D · rigid (different regime) |
| 100% modulus | 9.4 MPa | 6.2 MPa | 2-5 MPa typical | N/A · rigid plastics don't strain to 100% |
| Elongation at break | 330% | 600%+ | 200-700% | ~3-10% (rigid) |
| Service temperature | -20 to +80°C | -20 to +80°C | -60 to +250°C | varies · PA12-CF 131°C HDT |
| Chemical resistance | Poor · oils OK, acids/alkalis no | Poor · same as TPU95 | Excellent · broadly resistant | varies · PPS-CF excellent |
| Tooling cost | £0 · prints from CAD | £0 · prints from CAD | £1k-50k · injection mould needed | £0 · prints from CAD |
| Lead time · 50-unit batch | 6-9 working days | 7-10 working days | 4-8 weeks (tooling) + 1 week (parts) | 3-5 working days |
| Creep under sustained load | 3-8% over 1,000h at 20°C | 5-10% over 1,000h at 20°C | Near zero · best in class | Negligible · rigid |
| Cost per kg (filament) | £40-60 | £50-70 | £15-30 raw material + tooling | £20-50 (varies) |
| Best for | Gaskets, seals, shock absorbers, soft-touch grips, vibration isolators | Ultra-flex hinges, wearable contact, watch straps | High-volume + extreme-temperature + chemical-service | Load-bearing structural parts, fixtures, brackets |
This is 3DPE's standard process for TPU · the equipment and the dried-filament discipline are included, no surcharge. Slicer profile and orientation are tuned per part at quote stage.
File or sketch in. Tell us Shore hardness needed (90A / 95A), service load (static vs dynamic), temperature range, colour.
Reviewed inside 24 hours · per-unit cost + Shore hardness confirmation. Print time is the cost driver (TPU is slow).
Seal face orientation in XY for layer cohesion, infill ≥100% on sealing surfaces, creep allowance for sustained-load parts, wall thickness for flex features.
Filament dried at 65-70°C for 4-6 hours (TPU is hygroscopic · surface bubbles if not dried) · direct-drive extruder · 210-230°C nozzle, 25-60°C bed, 20-40 mm/s.
Matt rubber finish off the printer · flexible primer + automotive flexible paint where colour matters. Sanding impractical (TPU clogs sandpaper).
Tracked UK courier, tracking number sent the moment it leaves.
Lead times start when CAD is signed off and Shore hardness + colour are confirmed. Shore 90A (TPU90) is stocked on request · adds 1-2 days for filament procurement if not already in. Direct-drive extruder is required · all our TPU prints run on direct-drive printers.
Low-volume batch of custom-geometry flange gaskets printed in Shore 95A TPU · 100% infill on sealing surfaces, oriented with the seal face in XY for layer cohesion, matt rubber finish out of process. Replaces an injection-moulded gasket where the client could not justify tooling cost for a 50-unit run. Shore 95A is the industrial-standard flexible-service hardness for compression seals.
TPU (Shore 95A) is thermoplastic polyurethane · a segmented block copolymer of rigid urethane "hard" segments and flexible polyol "soft" segments chemically bonded along one chain. The hard segments are formed from a diisocyanate (MDI in this grade) reacted with a short-chain diol; they crystallise into physical cross-links at room temperature, melt at ~200°C, and re-form on cooling · this is what makes TPU thermoplastic. The soft segments (polyester or polyether polyols) have Tg around -50 to -70°C and contribute elasticity. Shore 95A is mid-hardness · firm-but-compliant, the same hardness as commercial moulded gaskets. 100% modulus 9.4 MPa, Young's modulus 29 MPa, elongation at break 330% (ISO 37 · rubber tensile · two orders of magnitude lower stiffness than rigid filaments). Density 1.20-1.24 g/cm³, equilibrium water absorption 0.82%. NOT chemically resistant to acids or alkalis · good for oils and greases. Practical service envelope -20°C to ~80°C.
"TPU is the material I reach for when the part needs to flex and recover · gaskets, shock absorbers, soft-touch grips, vibration dampers. Shore 95A is the same hardness as commercial moulded rubber gaskets, but we print it from CAD without injection-mould tooling. Two things engineers underestimate: TPU creeps under sustained static load (a compressed seal won't fully spring back after weeks), and TPU is broadly NOT chemically resistant · oils and greases are fine, but acids and alkalis degrade it. For sustained chemical or high-temperature elastomer service the right call is silicone (which we don't print but can advise on). For the rest, TPU does the job direct from your CAD."
Three questions worth answering before specifying TPU · what the block-copolymer microstructure does, why it creeps under load, and where the 80°C service ceiling really matters.
A diisocyanate (MDI in this grade · aromatic) reacts with a long-chain polyol to form alternating hard and soft segments along the polymer chain. The hard segments crystallise into physical cross-links at room temperature, melt at ~200°C, then re-form on cooling · this is what makes TPU thermoplastic. Print at 210-230°C, get rubber-like behaviour.
TPU's stress-strain curve is the elastomer signature · gentle initial slope, plateau through hundreds-of-percent strain, recovery on unload. Rigid filaments break at low strain (~7% for PETG, ~6% for PLA). TPU95 reaches the same stress level (~9 MPa) at 100% strain that rigid filaments hit at break · then keeps going.
Under sustained static load, TPU's soft-segment chains slowly slide past the hard-segment cross-links · the compressed shape becomes the new shape. A Shore 95A seal compressed 20% creeps 3-8% over 1,000 hours at 20°C, 10-15% at 60°C. Dynamic / cyclic loads spring back fully · creep only affects sustained-static loads. Design for the deformed state, or step to silicone for zero-creep service.
TPU is thermoplastic polyurethane · a segmented block copolymer of rigid urethane "hard" segments and flexible polyol "soft" segments chemically bonded along one chain. Hard segments are formed by reacting a diisocyanate (typically MDI · methylene diphenyl diisocyanate, aromatic, used in this grade · or HDI · hexamethylene diisocyanate, aliphatic, used in UV-stable grades) with a short-chain diol (1,4-butanediol typical). The hard segments crystallise into physical cross-links at room temperature, melt at approximately 200°C, and re-form on cooling.
Soft segments are long-chain polyols, typically polyester (poly-butylene adipate for abrasion resistance) or polyether (poly-tetramethylene glycol for hydrolysis resistance). They have Tg well below room temperature (-50 to -70°C) and contribute the elastic behaviour. The two segment types phase-separate at the nanometre scale (domain size 10-100 nm), producing a two-phase morphology that gives TPU its defining property: rubber-like elastic recovery from large strains, combined with melt-processability you can extrude through an FDM hot end. Shore hardness is controlled by the hard-segment / soft-segment ratio · TPU95 sits at approximately 40% hard content.
Under sustained static load, soft-segment Brownian motion lets chain segments slide past the hard-segment physical cross-links, producing permanent deformation. A Shore 95A TPU gasket compressed 20% at room temperature creeps approximately 3-8% over 1,000 hours · meaning when you release the load the seal recovers most but not all of the original compression. At 60°C the same gasket creeps 10-15% over the same period, because the soft-segment motion accelerates with temperature.
Design implication: for sustained-load service, oversize the initial compression interference to account for expected creep. For zero-creep flexible service, specify silicone (chemical cross-linking eliminates the slip mechanism · but requires injection-mould tooling). For cyclic / dynamic loads, TPU springs back fully on each unload cycle · creep only accumulates under sustained static stress.
The hard segments soften progressively as temperature rises. The hard segments are what hold the TPU network in place at room temperature · once they begin to flow, the soft-segment elasticity has nothing to spring against. The practical service ceiling is approximately 80°C continuous · above this, TPU stretches further under the same load and recovers less. By approximately 200°C the hard segments fully melt and the polymer flows as a thermoplastic (which is what makes it 3D-printable in the first place).
Steam autoclave at 121°C is well above the service ceiling · parts soften, lose elastic recovery, and the polyester polyol backbone is also vulnerable to steam hydrolysis. For sterilisation use EtO, gamma, or IPA wipe-down · all work at room temperature. For repeated steam autoclave service in flexible parts, specify medical-grade silicone (requires moulding tooling). For sustained outdoor service in direct sun, specify aliphatic HDI-based TPU (on request · UV-stable, separate SKU).
Values measured to the ISO standards cited in the right-hand column, on the manufacturer's own injection-moulded test specimens · directly comparable to other engineering thermoplastics.
| Property | XY · print plane | Z · build axis | Unit | Standard |
|---|---|---|---|---|
| Mechanical · rubber tensile (ISO 37) | ||||
| 100% modulus (stress at 100% strain) | 9.4 ± 0.3 | N/A | MPa | ISO 37 |
| Young's modulus | 29 ± 2.8 | N/A | MPa | ISO 37 |
| Elongation at break | 330.1 ± 14 | N/A | % | ISO 37 |
| Shore hardness | 95A | Shore A | ISO 7619-1 | |
| Tensile/flex Z-axis values | N/A · TDS V5.1 publishes XY only | · | · | |
| Charpy / Izod impact | N/A · ISO 179 not standard for elastomers | · | · | |
| Thermal · rubber elastomer · HDT-style tests do not apply | ||||
| Heat deflection (HDT) | N/A · rubber elastomer · rigid-plastic HDT does not apply | · | ISO 75 | |
| Glass transition (Tg) | N/A · TDS does not publish · TPU literature soft-segment Tg approx -50 to -70°C | · | DSC | |
| Vicat softening | N/A · TDS does not publish | · | ISO 306 | |
| Practical service temperature range | -20 to +80 | °C | TPU literature | |
| Physical | ||||
| Density | 1.20 to 1.24 | g/cm³ @ 23°C | ISO 1183 | |
| Equilibrium water absorption | 0.82 | % | TDS V5.1 | |
| Melt flow rate | 3 to 6 | g/10 min | 210°C, 1.2 kg | |
| Chemical resistance · manufacturer-rated · broadly NOT resistant | ||||
| Weak acids | Not resistant | · | TDS V5.1 | |
| Strong acids | Not resistant | · | TDS V5.1 | |
| Weak alkalis | Not resistant | · | TDS V5.1 | |
| Strong alkalis | Not resistant | · | TDS V5.1 | |
| Oils and greases | Good · TPU literature | · | TDS gap | |
| Alcohols (IPA, ethanol) | Good · TPU literature | · | TDS gap | |
| Petrol / aromatic hydrocarbons | Poor · swells polyester TPU | · | TPU literature | |
| Cosmetic / supply | ||||
| Stock colour range | 20+ colours (incl. translucent + clear grades) | · | workshop stock | |
| Custom RAL match | Yes (1-2 day procurement) | · | on request | |
| Finish grades available | Matt rubber as-printed · sanding impractical (TPU smears); flexible 2K coatings only | · | workshop stock | |
| Food-contact rating | Not food-contact certified · printed FDM grade not certifiable in this form | · | supplier disclaimer | |
For TPU gaskets and seals, orient the seal face in XY so layer lines run parallel to the sealing direction · this maximises layer cohesion at the wet-out interface. Loading across layer lines (Z direction) introduces leak paths between layers. TPU TDS V5.1 publishes XY values only · Z anisotropy is present but secondary to layer-orientation strategy.
TPU's compliance means thin walls deflect under finger pressure · for gaskets and structural seals, 1.2 mm structural / 2.0 mm for compression-loaded surfaces. For thin flex features (membrane keypads, sensor diaphragms), 0.8 mm is the floor before tearing. Hubs / Protolabs Network FDM minimums apply. We DFM-check wall thickness against the part's load case at quote stage.
45° is the slicer-default support threshold across every major FDM tool · TPU's flexible melt sags more under gravity than rigid filaments, so the practical bridging limit is shorter (typically 3-4 mm before support is needed vs 5 mm+ for rigid). The cooling fan helps but TPU can't be cooled aggressively without surface defects. We DFM-check overhangs at quote stage and recommend orientation.
TPU dimensional tolerance is wider than rigid filaments because the part itself deflects under calliper pressure. Standard FDM ± 0.5% / ± 0.5 mm envelope applies but for tight-fit features (seal interferences, snap-fits) we use no-touch optical measurement. Exact tolerance depends on part size, geometry, and load case · we confirm achievable tolerance against your CAD at quote stage.
The flexible matrix balls up on sandpaper grit · sanding doesn't work as standard finishing. For smooth surfaces, plan for low layer height (0.1 mm) in the print and live with the matt rubber finish. The natural texture is usually acceptable for gaskets, grips, and shock absorbers.
Wet TPU (the spool has been in humid air more than ~3 days) prints with surface bubbles, stringy extrusion, and reduced layer adhesion · TPU absorbs 0.82% water at equilibrium, higher than rigid filaments. We run this on every spool before the bed.
Rigid 2K spray paints crack as TPU flexes · use flexible (rubber-bonding) primer + automotive flexible paint instead. Adds 0.05-0.10 mm per surface. Stock-coloured filament is the easier route · matt rubber finish off the printer is usually fine for industrial parts.
Off-the-printer TPU has a slightly tacky matt rubber surface that picks up workshop dust. A light talc or PTFE-dust treatment (industrial standard for moulded elastomers) reduces tack and makes parts easier to install and inventory. Optional · most gaskets/seals don't need it but cosmetic and consumer-facing parts often benefit.
Every value on this page traces to an ISO test method · the manufacturer's TPU95 TDS V5.1 EN, cross-checked against the PDF in-session. ISO 37 (rubber tensile) replaces ISO 527 for elastomers · we don't quote derived numbers without naming the standard.
No offshore subcontracting. Files, prints, and couriers all stay in the UK · TPU runs on direct-drive extruders (Bowden tubes let TPU buckle and tangle) and every spool is dried at 65-70°C for 4-6 hours before the bed.
Send three things: Shore hardness needed (90A vs 95A), load type (sustained-static / dynamic-cyclic / impact), and service temperature + chemistry. our team come back inside 24 hours · if silicone or a rigid material is a better fit, we say so.
our team review every brief before quote. No ticket queue, no account managers.
According to the PolyFlex TPU95 TDS, TPU95 delivers Shore 95A hardness (ISO 7619-1) with 551 ± 24% elongation at break and stress @300% of 21.0 ± 0.7 MPa · flexible elastomer, no Tg/Tm/HDT published.
TPU is our flexible 3D printing material. We print Shore 95A TPU at 210–230°C on a direct-drive extruder, slowly · flexible filament buckles in a Bowden path · with the spool dried at 65–70°C for 4–6h first or you get surface bubbles. The real lever on a flexible part is design, not just the material: wall count, infill density and pattern set how stiff or rubbery the finished part actually feels, and we tune those per part at quote stage.
Shore 95A. That is firm-but-compliant · squishy under a thumb, recovers instantly, similar feel to a hard rubber wheel or a tyre tread. Most commercial moulded gaskets and phone-case inserts sit at Shore 93-95A. For softer parts, 3DPE stocks Shore 90A on request (softer, more rubber-band-like, elongation 600%+). Shore A is the rubber hardness scale · rigid filaments (PLA, PETG, ABS) all sit at Shore D · a different mechanical regime.
Both give elastomer behaviour. TPU wins on: no moulding tooling cost (FDM from CAD directly), geometry freedom (internal channels, lattices, complex shapes), fast lead time (no mould lead time), oil and grease compatibility. Silicone wins on: temperature range (-60°C to +250°C vs TPU's -20°C to ~80°C), chemical resistance (broadly resistant vs TPU broadly not), biocompatibility for medical, and lower creep under sustained load. For small-batch + custom geometry + room-temperature service, TPU. For mass-production + extreme-temperature + chemical service, silicone (we don't print silicone but can advise).
Yes · this is TPU's Achilles heel. Sustained static load causes slow permanent deformation. A Shore 95A TPU seal compressed 20% at room temperature creeps approximately 3-8% over 1,000 hours. At 60°C the same seal creeps 10-15%. The cause is the segmented block-copolymer microstructure · soft-segment Brownian motion lets chain segments slide past the hard-segment physical cross-links under sustained load. Design for the deformed state (over-size the initial interference), or step to silicone for true zero-creep service. For dynamic / cyclic loads TPU springs back fully · creep is only an issue for sustained static loads.
This grade · MDI-based aromatic TPU · yellows and embrittles over months of direct sun. Aliphatic HDI-based TPU is UV-stable but is a different SKU (on request, longer lead time). For short-term outdoor service (under 6 months) the aromatic TPU we stock holds up reasonably. For multi-year outdoor flexible parts, specify the aliphatic TPU on request, or UV-overcoat the part with a flexible primer.
Per the manufacturer TDS · NOT resistant to weak acids, strong acids, weak alkalis, or strong alkalis. Good for oils, greases, alcohols (IPA, ethanol). Poor for petrol, aromatic hydrocarbons, ketones. For sustained chemical service in flexible elastomers, specify silicone or fluoroelastomer (FKM) · we'll advise the right spec.
| Chemical / family | Resistance | Notes |
|---|---|---|
| Weak acids (acetic, citric, dilute organic) | Not resistant | Manufacturer TDS rating · degrades polyester TPU backbone |
| Strong acids (sulphuric, HCl, nitric) | Not resistant | Manufacturer TDS rating · rapid attack |
| Weak alkalis (dilute soap, mild bleach) | Not resistant | Manufacturer TDS rating · hydrolyses ester bonds |
| Strong alkalis (caustic soda, ammonia) | Not resistant | Manufacturer TDS rating · rapid hydrolysis |
| Oils, greases (mineral, motor, hydraulic) | Good | TPU literature · why TPU is used for automotive seals |
| Alcohols (IPA, ethanol wipe-down) | Good | Surface cleaning · sustained immersion limited |
| Cold water, sea water (cold) | Limited | TPU absorbs 0.82% water · polyester TPU slowly hydrolyses in sustained water |
| Hot water (sustained > 60°C) | Poor | Approaches service ceiling · hydrolysis accelerates |
| Steam autoclave (121°C) | Fails | Well above ~80°C ceiling · parts soften and deform |
| Petrol, diesel | Poor | Swells polyester TPU · loses strength |
| Aromatic hydrocarbons (toluene, xylene) | Poor | Swells and degrades |
| Ketones (acetone, MEK) | Limited | Brief OK · sustained attacks the polymer |
| Ozone (outdoor + electrical service) | Good | TPU literature · resistant to ambient ozone |
| UV exposure (UK outdoor, aromatic MDI grade) | Limited | Yellows in months · multi-year requires aliphatic TPU SKU |
| Skin contact (short-duration) | Good | OK for tool grips, watch straps · medical-grade requires certified TPU SKU |
First five rows are direct manufacturer TDS ratings (TDS V5.1 EN). Remaining rows reflect industry TPU behaviour and 3DPE workshop experience · brief contact is always more forgiving than sustained exposure. For sustained chemical-service flexible parts the right call is silicone or FKM (which we don't print but can advise on).
No · the flexible matrix absorbs internal stress rather than locking it in. Bed adhesion on PVA glue, Magigoo, BuildTak, glass, or blue tape is generally good. The bigger print issue is wet filament producing surface bubbles, stringy extrusion, and reduced layer adhesion · TPU is hygroscopic (0.82% equilibrium water absorption) so every spool is dried at 65-70°C for 4-6 hours pre-print. The second print issue is filament buckling in Bowden tubes · TPU prints best on direct-drive extruders (we run direct-drive on every TPU job).
TPU is hygroscopic · equilibrium water absorption is 0.82% (per TDS V5.1). The segmented urethane matrix absorbs more water than rigid filaments. Water in the filament flashes to steam at the nozzle, producing visible surface bubbles, stringy extrusion, and reduced layer adhesion. Pre-print drying at 65-70°C for 4-6 hours is essential for production work · every TPU spool runs through a drier before the bed.
Usually yes, for short-term or room-temperature service. 3DPE prints with at least 100% infill on gasket sealing surfaces, oriented with the seal face in XY for best layer-cohesion. For sustained immersion, high pressure, or autoclave-cycle service, silicone is the right call. TPU's strengths over silicone: no tooling cost, geometry freedom, faster lead time, better oil/grease compatibility. TPU's weaknesses: lower service temperature, higher creep, broader chemical sensitivity.
TPU bonds with TPU-specific cyanoacrylate (rubber-bonding grade) and with 2-part urethane adhesives. Acetone and most common solvents do not dissolve or fuse TPU. For elastomer-to-rigid bonds, primer-based urethane adhesives are the strongest joint. Heat-set inserts work but the flexible matrix tends to grip-and-relax over time · for permanent threaded inserts in TPU, consider overmoulding around rigid fasteners. Ultrasonic welding works but requires equipment that can accommodate TPU's compliance.
No. Steam autoclave at 121°C is well above TPU's ~80°C continuous-service ceiling · parts soften and deform, and the polyester backbone hydrolyses in steam. EtO sterilisation, gamma irradiation, and IPA wipe-down all work for TPU. For repeated steam-autoclave service in flexible parts, specify medical-grade silicone (requires moulding tooling).
TPU has no formal HDT, Tg, Tm, or Vicat published in the TDS · rubber elastomers don't deform under load the same way rigid plastics do. Practical service envelope per TPU literature: -20°C to ~80°C continuous. Below -20°C, TPU stiffens significantly toward glassy. Above 80°C the hard segments soften and TPU loses elastic recovery. Engine-bay heat, direct summer sun on dark surfaces, and near-radiator service all push TPU past its envelope. For wider temperature elastomer service, silicone (-60°C to +250°C) is the step-up.
Filament cost is roughly £40-60/kg for stock-colour TPU95 · above PETG and PLA, similar to ASA, well below PA12-CF (£90-130/kg). Print time is the bigger cost driver · TPU prints at 20-40 mm/s vs 50-100 mm/s for rigid filaments. For a typical gasket or shock-absorber prototype, material is 10-20% of the unit cost and print time is the rest. Send the brief and we'll quote the actual job.
You'll hear back from our team within 24 hours · with material-fit check (TPU90 vs TPU95 vs silicone-step-up advice), creep allowance for sustained-load parts, lead-time confirmation, and Shore-hardness coupon if it'd help confirm the feel before printing.