ISO 6916-2:2024

Overview

ISO 6916-2:2024 is the International Standard that specifies classification and requirements for flexible cellular polymeric materials described as sponge and expanded cellular rubber products manufactured as mouldings and extrusions. It covers vulcanized cellular rubber made from natural, reclaimed or synthetic rubber (thermoplastic rubbers, latex foam rubbers and shoe soling are excluded). Manufacturing processes covered include moulding and continuous vulcanization methods such as hot‑air, microwave, infra‑red, liquid curing medium (LCM) and shearing‑head vulcanization.

Key topics and technical requirements

• Classification system: products are classified by Type (Type 1 open‑cell, Type 2 closed‑cell, Type 3 self‑skinned), Class (A–D based on base polymer and oil/temperature resistance), Grade (0–6 based on firmness) and optional suffixes indicating additional properties or test conditions.
• Firmness (grades): grades are defined by compression deflection ranges (e.g., Grade 0: 2.5–15.0 kPa; Grade 1: 15.1–35.0 kPa; up to Grade 6: 200.1–300.0 kPa).
• Physical property requirements: tables specify baseline requirements for different type/class/grade combinations, including density, compression behavior and other performance limits.
• Test methods and annexes: normative test procedures are provided (Annexes A–G) covering temperature resistance, compression deflection, oil resistance, compression set, water absorption, fluid resistance and low‑temperature resistance.
• Quality controls: rules for sampling, inspection and rejection, storage before testing, dimensional tolerances for mouldings/extrusions, and packaging/marking.
• Priority rule: specific product test methods or detailed specifications take precedence if conflicts arise.

Practical applications and users

ISO 6916-2 is used by:

• Manufacturers and compounders of sponge and expanded rubber mouldings/extrusions for consistent product specification and quality control.
• Design engineers and specifiers selecting seals, gaskets, cushioning, vibration‑damping and weather‑sealing components requiring defined firmness, oil or temperature resistance.
• Test laboratories and quality inspectors performing compression, oil resistance, low‑temperature and dimensional tests in accordance with the standard.
• Procurement professionals and certifiers who require standardized material performance for industrial, automotive, construction and other applications.

Related standards

• ISO 6916-1 (sheeting materials)
• Referenced test standards used in ISO 6916-2: ISO 188, ISO 815-1, ISO 1431-1, ISO 1817, ISO 1923, ISO 3865, ISO 5893

Keywords: ISO 6916-2, sponge rubber, expanded cellular rubber, mouldings and extrusions, compression deflection, oil resistance, dimensional tolerances, vulcanized cellular rubber, continuous vulcanization.