ISO 16365-2:2014

Overview

ISO 16365-2:2014 defines standardized methods for the preparation of test specimens and the determination of properties of thermoplastic polyurethanes (TPU) intended for moulding and extrusion. The standard covers specimen preparation, handling and conditioning of test material, injection‑moulding practice for test specimens, and the environmental/test conditions required to obtain reproducible, comparable TPU property data.

Key topics and technical requirements

• Material handling and moisture control

  • Granules must reach room temperature and have a moisture content ≤ 0.02 % (m/m).
  • Drying: dehumidified air dryer recommended (e.g., 3 h at 100 °C may be sufficient); circulating‑air ovens require ~+20 °C. Longer drying (up to 1 day at 110 °C) is permitted if proven.
  • Use of premixes is recommended when adding masterbatches or pigments. Store granules in moisture‑proof containers and minimize exposure to air; blanketing in the feed hopper with dry gas (dry air, N2, Ar) or using a dehumidifier hopper drier is advised.

• Specimen preparation and injection moulding

  • Specimens shall be prepared by injection moulding in accordance with ISO 294-1 and related parts.
  • Recommended processing temperature ranges vary by Shore D hardness (examples):
    • Soft (D < 25): heating zone ~200–220 °C; nozzle ~210–230 °C; melt ~205–225 °C.
    • Medium (25 ≤ D < 65) and Rigid (D ≥ 65) have higher ranges accordingly.
  • Typical pressures: injection 10–100 MPa; holding 10–100 MPa; back pressure 0.5–2 MPa.
  • Melt flow guidance: target MFR/MVR in the range 5–100 cm3/10 min, preferably 10–40 cm3/10 min (see ISO 1133-2).

• Conditioning

  • TPUs may need annealing to reach full mechanical properties; recommended annealing 20 h at 100 °C.
  • After annealing, specimens can be tested following 24 h storage at 23 °C and 50 % RH.
  • Standard testing atmosphere: 23 ± 2 °C and 50 ± 10 % RH unless otherwise stated.

• Test reproducibility

  • To ensure comparable data use the specified preparation, specimen dimensions and test procedures. Differences in mechanical properties due to flow direction should be reported if > 5 %.

Applications and users

• Intended for materials and process engineers, QA/test laboratories, compounders, TPU manufacturers, and OEMs who need reliable, comparable property data for:
  • Material specification and certification
  • Comparative evaluation of TPU grades (polyether and polyester TPUs)
  • Quality control of moulding and extrusion batches
  • Data for design decisions where TPU mechanical, thermal, electrical or biological resistance properties matter

Related standards

Normative references include: ISO 16365-1, ISO 10350-1, ISO 294 (parts 1,3,4), ISO 1133-2, ISO 291, ISO 868, ISO 527, ISO 1183, ISO 15512, and several IEC methods for electrical and flammability testing. These referenced standards should be consulted for detailed test methods and specimen geometries.

Keywords: ISO 16365-2, TPU, thermoplastic polyurethane, test specimens, injection moulding, conditioning, annealing, moisture content, MFR, MVR, Shore D hardness.