ISO 17855-2:2024

Overview

ISO 17855-2:2024 - Plastics - Polyethylene (PE) moulding and extrusion materials - Part 2 - defines the procedures for preparing test specimens and determining the properties of polyethylene (PE) moulding and extrusion materials. The standard sets out handling, conditioning and specimen-preparation requirements (injection moulding or compression moulding) and lists the test methods essential to characterise PE materials. Its purpose is to ensure reproducible and comparable test results for material specification, quality control and product development.

Key topics and technical requirements

• Specimen preparation methods: mandates consistent use of either injection moulding or compression moulding for a given material and test series.
  • Injection moulding is specified for materials with MFR ≥ 1 g/10 min (ISO 1133-1). Example conditions given include a melt temperature of 210 °C and controlled injection velocities and holding times to produce blemish‑free specimens.
  • Compression moulding is used for MFR < 1 g/10 min, thin specimens (≤ 2 mm) or when specified. Typical moulding temperature example: 180 °C with controlled preheating and full-pressure cycles.
• Treatment and conditioning: no routine pre‑treatment before moulding is normally required. Unfilled PE specimens are conditioned for at least 16 h at 23 °C ± 2 °C; materials sensitive to moisture require conditioning at 23 °C ± 2 °C and (50 ± 10) % RH unless otherwise justified.
• Test methods and properties: lists properties selected from ISO 10350-1 and other widely used methods - tensile, flexural, impact, thermal analysis (DSC/TMA), density, melt flow (MFR/MVR) and specific resistance tests for slow crack growth and environmental stress cracking (referenced standards apply).
• Reproducibility note: results are comparable when specimens, dimensions and procedures conform to this part; values may differ if other specimen dimensions or preparation methods are used.

Practical applications and users

Who uses ISO 17855-2:

• PE resin manufacturers and compounders - to specify and certify material data sheets.
• Test laboratories and quality control teams - to prepare specimens and run standardised tests for acceptance testing.
• Product designers and R&D - to compare materials and assess suitability for moulding and extrusion applications.
• Specification writers, procurement and regulators - to reference reproducible test data in contracts and standards.

Practical benefits:

• Ensures consistent test specimen preparation for accurate comparison of PE grades.
• Supports reliable evaluation of mechanical, thermal and durability properties (including guidance to link to piping-specific slow crack growth tests).
• Facilitates material selection, supplier comparison and regulatory compliance.

Related standards

Relevant references include ISO 17855-1 (designation system), ISO 10350-1, ISO 1133-1 (MFR/MVR), ISO 294 series (injection moulding), ISO 293 (compression moulding), ISO 2818 (machining specimens), ISO 16241 / ISO 16770 / ISO 18488 / ISO 18489 and ISO 22088-2 (slow crack growth / ESC methods), and ISO 20753 (test specimen types).