TPU-Caprolactone 55D
Hardness band
ISO 18064 TPU-C
55D = shore 55D
Semi-rigid grade for ski boots, gears, couplings and structural wear parts needing stiffness plus toughness.
Values for the 55D condition
Other TPU-Caprolactone grades and fills
TPU-Caprolactone is listed in 7 conditions; see the grade overview at TPU-Caprolactone.
Compare all 7 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Flame retardant, halogen-free | Pick for cable jackets, industrial connectors and rail/E&E parts requiring UL 94 V-0 at 1.5–3 mm. | — | 30 | 380 | 37 Shore D |
Antistatic / ESD conductive | Carbon-black or ionic-antistat compound for fuel-line covers, mining belts and ESD-safe hoses and rollers. | — | 35 | 400 | 38 Shore D |
Solution / adhesive & coating grade | Linear, solvent-soluble (MEK/DMF/THF) high-molecular-weight TPU-C for shoe adhesives, laminating films and textile coatings. | — | 35 | 650 | 28 Shore D |
Shore 80A | Choose for flexible tubing, soft films and adhesive/laminating layers needing high elongation. | — | 38 | 620 | 29 Shore D |
Shore 90A | Best all-round abrasion/oil grade for rollers, seals, conveyor components and shoe soles. | — | 50 | 500 | 38 Shore D |
Shore 95A | For high-load wear parts, wheels, hydraulic seals and stiff jacketing where creep resistance matters. | — | 55 | 450 | 46 Shore D |
55DThis page Shore 55D | Semi-rigid grade for ski boots, gears, couplings and structural wear parts needing stiffness plus toughness. | — | 55 | 380 | 55 Shore D |
What is TPU-Caprolactone 55D?
TPU-Caprolactone 55D is TPU-Caprolactone heat treated to 55D — semi-rigid grade for ski boots, gears, couplings and structural wear parts needing stiffness plus toughness. TPU-Caprolactone 55D has a tensile strength of 55 MPa (7.98 ksi), stronger than 61% of polymer grades. Elongation at break is 380% and the elastic modulus is 0.2 GPa (0.029 Msi). TPU-Caprolactone 55D has a density of 1.23 g/cm³ (0.0444 lb/in³), heavier than 62% of polymer grades. Its glass-transition temperature is -50°C (-58 °F).
Advantages
- Forms and bends easily — 90/100, better than 91% of polymer grades
- Readily welded — 85/100, better than 89% of polymer grades
- Ductile — tolerates forming and impact — 380%, better than 85% of polymer grades
Limitations
- Absorbs moisture — dry before molding — 0.6%, worse than 75% of polymer grades
TPU-Caprolactone 55D properties
Typical room-temperature values for TPU-Caprolactone 55D; 11 are specific to this condition. Other listed values are TPU-Caprolactone reference data and may not represent this condition. Bars are the position among polymer grades.
Physical5
TPU-Caprolactone 55D has a density of 1.23 g/cm³ (0.0444 lb/in³), heavier than 62% of polymer grades. Its glass-transition temperature is -50°C (-58 °F).
Mechanical8
TPU-Caprolactone 55D has a tensile strength of 55 MPa (7.98 ksi), stronger than 61% of polymer grades. Elongation at break is 380% and the elastic modulus is 0.2 GPa (0.029 Msi).
Thermal9
TPU-Caprolactone 55D is rated for continuous service to 95°C (203 °F). It conducts heat at 0.2 W/m·K (0.116 BTU/hr·ft·°F), worse than 56% of polymer grades. Thermal expansion is 175 µm/m·K (97.2 µin/in·°F).
Electrical6
TPU-Caprolactone 55D is an electrical insulator with a dielectric strength of 25 kV/mm (635 V/mil) and a resistivity of 1×10⁹ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (78/100), worse than 61% of polymer grades. UV resistance is fair.
Sustainability4
Producing a kilogram of TPU-Caprolactone 55D takes about 125 MJ of energy and emits 6 kg of CO₂ — more than 75% of polymer grades. Typical recycled content is 0%.
Manufacturability8
TPU-Caprolactone 55D's machinability is fair (50/100, worse than 73% of polymer grades); weldability excellent (85/100); formability excellent (90/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with TPU-Caprolactone 55D
Is TPU-Caprolactone easy to machine?
Machinable only on rigid (55D+) grades with sharp, high-rake tools, high speed and low feed; soft grades smear and need freezing or water-jet/die cutting.
Can TPU-Caprolactone be welded?
Excellent HF (dielectric), ultrasonic, hot-plate and hot-air welding; solvent bonding with DMF/THF blends and polyurethane adhesives works well.
Can TPU-Caprolactone be formed, bent or molded?
Dry 2–3 h at 100–110 °C to <0.02 % moisture, inject at 190–225 °C melt / 20–50 °C mold, avoid shear-degradation and long residence times; extrudable into film, tube and profile.
What surface finishes work on TPU-Caprolactone?
Takes PU-based paints, flock and printing after corona/flame or primer treatment; can be textured directly in the mold, but polishing to a high gloss is limited by its elastomeric surface.
TPU-Caprolactone chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| polycaprolactone diol (soft segment)PCL polyol, typ. Mn 1000–2000 g/mol; source of hydrolysis/microbial resistance | 50 – 70 | 60 |
| 4,4'-MDI (diisocyanate)aromatic; TDI/HDI/H12MDI used for light-stable variants | 22 – 35 | 29 |
| 1,4-butanediol (chain extender)forms hard segment with MDI | 5 – 12 | 9 |
| additives (waxes, antioxidant, UV, FR, pprocess aids and stabilizers | 0.2 – 3 | 1 |
TPU-Caprolactone 55D — frequently asked
What is TPU-Caprolactone 55D used for?
TPU-Caprolactone 55D is typically used for hot-melt adhesives, coatings, specialty films and cable insulation. In short: balanced ester/ether TPU; highest TPU service temperature; adhesive and coating grade.
What is the tensile strength of TPU-Caprolactone 55D?
TPU-Caprolactone 55D has a typical tensile strength of 55 MPa (7.98 ksi) — stronger than 61% of polymer grades. Strength varies by condition: see the 7 listed tempers.
Is TPU-Caprolactone 55D easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 73% of polymer grades). Machinable only on rigid (55D+) grades with sharp, high-rake tools, high speed and low feed; soft grades smear and need freezing or water-jet/die cutting.
Can TPU-Caprolactone 55D be welded?
Yes — weldability is rated excellent (85/100). Excellent HF (dielectric), ultrasonic, hot-plate and hot-air welding; solvent bonding with DMF/THF blends and polyurethane adhesives works well.
What surface finishes work on TPU-Caprolactone 55D?
Takes PU-based paints, flock and printing after corona/flame or primer treatment; can be textured directly in the mold, but polishing to a high gloss is limited by its elastomeric surface.
Can TPU-Caprolactone 55D be formed, bent or molded?
Dry 2–3 h at 100–110 °C to <0.02 % moisture, inject at 190–225 °C melt / 20–50 °C mold, avoid shear-degradation and long residence times; extrudable into film, tube and profile.
What is the maximum service temperature of TPU-Caprolactone 55D?
TPU-Caprolactone 55D is rated for continuous use to about 95°C (203 °F), and briefly to 120°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ISO 18064 — Thermoplastic elastomers, nomenclature and abbreviated terms — ISO (2014)
- ISO 37 / ISO 868 / ISO 34-1 / ISO 815 — rubber test methods — ISO (2019)
- Elastollan C-series (polycaprolactone TPU) product range and processing guide — BASF Polyurethanes (2023)
- Desmopan / Texin TPU selection and processing data — Covestro (2023)
- CAPA polycaprolactone polyols for TPU technical brochure — Perstorp (2022)
- Engineered Materials Handbook, Vol. 2: Engineering Plastics — ASM International (1988)
- CAMPUS plastics database — TPU (ester) property sets — CWFG / CAMPUS consortium (2024)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.