EN ISO 899-1:2017 PDF

Overview

EN ISO 899-1:2017 - Plastics: Determination of creep behaviour - Part 1: Tensile creep specifies a standardized method to measure the tensile creep of plastics using dumb-bell-shaped test specimens under controlled conditions (pretreatment, temperature, humidity). It applies to rigid and semi-rigid plastics - non-reinforced, filled or fibre‑reinforced - either moulded directly or machined from sheets. The standard is intended to produce reproducible data for engineering design, research and quality control.

Key topics and technical requirements

• Scope of testing: Tensile creep measured on standard specimens; suitable for engineering-design, R&D and quality-control purposes.
• Specimen types: Dumb‑bell-shaped specimens moulded or machined from articles or sheets; dimensions and preparation significantly affect results.
• Conditioning and environment: Conditioning to standard atmospheres (temperature and relative humidity) is required; thermal history and humidity control critically influence creep behaviour (see informative Annex A on physical ageing effects).
• Measurement methods:
  • For engineering‑grade data, use extensometers to measure gauge‑length strain precisely.
  • For research or QC, nominal extension (grip separation change) may be used.
• Test procedure elements:
  • Apparatus, specimen measurement and mounting
  • Selection of initial stress and loading / preloading procedures
  • Extension‑measurement schedule and time measurement
  • Optional measurement of recovery after unloading
• Results and calculations:
  • Tensile‑creep strain and nominal tensile‑creep strain
  • Tensile‑creep modulus (E_t) and nominal tensile‑creep modulus (E*_t)
  • Presentation formats: creep curves, creep‑modulus/time curves, isochronous stress‑strain curves, 3‑D representations and creep‑to‑rupture curves
• Reporting and precision: Test report requirements and precision guidance are included; when precise comparisons are required, specimen prep, thermal history and environment must be tightly controlled.
• Normative references: ISO 291, ISO 472, ISO 527 series.

Applications and who uses it

• Product designers and engineers use EN ISO 899-1:2017 to assess long‑term deformation (creep) for load‑bearing plastic components, to inform safety factors and lifetime predictions.
• Materials researchers and R&D labs employ the method to compare formulations, additives, fillers and reinforcement effects on creep behaviour.
• Quality‑control and testing laboratories use the procedure for batch verification where nominal extension measurement is acceptable.
• Regulatory bodies and standards committees reference the standard when specifying mechanical performance requirements for plastics.

Related standards

• ISO 527 (tensile properties)
• ISO 291 (conditioning)
• ISO 472 (plastics vocabulary)

Keywords: EN ISO 899-1:2017, tensile creep, plastics creep behaviour, tensile‑creep testing, extensometer, creep modulus, isochronous curves, creep‑to‑rupture.