Overview
ISO/TS 16095:2021 specifies an evaluation procedure for reclaimed rubber derived from products containing mainly natural rubber. It defines the physical and chemical tests on raw reclaimed natural rubber, and the standard materials, test formulations, equipment, and processing methods used to evaluate vulcanization characteristics and mechanical properties of reclaimed natural rubber. The technical specification is intended for laboratories, reclaimers, compounders and quality teams working with recycled natural rubber.
Key topics and technical requirements
- Sampling and sample preparation: laboratory sample (~1.5 kg) and preparation per ISO 1795 procedures.
- Physical and chemical tests:
- Mooney viscosity (recorded as ML(1+4) at 100 °C) using ISO 289-1.
- Acetone extract (ISO 1407, method A or B).
- Ash content (ISO 247-1, method A).
- Carbon black content (ISO 1408, method A).
- Rubber content calculated per ASTM D297 clauses cited (R = 100 – (carbon black + ash + acetone extract)).
- Standard test formulation: detailed formulation (base reclaimed rubber plus stearic acid, zinc oxide, sulfur, MBT, DPG) and explicit handling of reclaimed-specific constituents (x = carbon black parts, y = acetone extract parts, z = ash parts).
- Mixing and processing: laboratory mill mixing procedure with roll temperature control (40 °C ± 5 °C), specified timing and passes, batching, sheeting thicknesses and conditioning (2–24 h) prior to molding.
- Vulcanization and cure assessment: curemeter testing using oscillating-disc (ISO 6502-2) or rotorless curemeter (ISO 6502-3) with defined die temperature (140 °C ± 0.3 °C), oscillation frequency (1.7 Hz), and amplitude guidance.
- Physical property tests on vulcanizates: Mooney viscosity of test mixes (ISO 289-1), tensile stress–strain (ISO 37) after vulcanization at 140 °C for 20 min, and Shore A hardness (ISO 48-4).
- Test reporting: mandatory items include reference to ISO/TS 16095:2021, sample ID, methods used for ash/acetone extract/carbon black, reference materials, ambient conditions, curemeter type and settings, results and units, and test date.
Applications and users
Who benefits:
- Rubber reclaim businesses verifying reclaimed natural rubber quality for resale.
- Compounders and formulators assessing compatibility and adjusting recipes for recycled content.
- Quality control and test laboratories performing acceptance testing, supplier qualification, and batch verification.
- R&D teams and material scientists evaluating performance of reclaimed natural rubber in new products.
Practical uses include supplier acceptance criteria, comparative benchmarking, recycling process optimization, and ensuring consistent vulcanization and mechanical performance when reclaimed rubber is blended into new formulations.
Related standards
Key referenced standards: ISO 37, ISO 48-4, ISO 1795, ISO 1407, ISO 1408, ISO 247-1, ISO 289-1, ISO 6502-2, ISO 6502-3, ASTM D297. These provide the referenced test methods and conditioning procedures used throughout ISO/TS 16095:2021.
Keywords: ISO/TS 16095, reclaimed rubber, reclaimed natural rubber, evaluation procedure, Mooney viscosity, curemeter, vulcanization characteristics, carbon black, acetone extract, ash content, rubber testing.