Overview
ISO/TR 19032:2019 - Plastics - Use of polyethylene reference specimens (PERS) for monitoring laboratory and outdoor weathering conditions - describes a method to use polyethylene reference specimens (PERS) to monitor and quantify the combined effects of ultraviolet (UV) radiation and temperature in both laboratory-accelerated and outdoor weathering tests. The technical report explains specimen preparation, measurement of the carbonyl index by infrared spectroscopy, round‑robin testing (RRT) of laboratory light‑source exposure devices, and comparisons between laboratory and outdoor exposures.
Key topics and requirements
- Scope: Demonstrates use of PERS for monitoring laboratory and outdoor weathering conditions for plastics.
- PERS material characteristics (reported example): high‑density polyethylene polymerized with molybdenum dioxide catalyst, contains trans‑vinylene groups; typical density ~950–965 kg/m3, thickness ~0.2 mm, melt flow rate ~0.2–0.4 g/10 min.
- Specimen preparation: roll‑kneading and compression moulding steps with specified temperatures and timings to produce consistent film thickness.
- Carbonyl index measurement:
- Use an IR spectrophotometer to record absorbance 2 200–1 600 cm−1.
- Use the absorbance near 1 715 cm−1 (carbonyl peak) and an internal standard near 2 020 cm−1 to calculate a carbonyl index (absorbance ratio) that reflects photo‑oxidation.
- Laboratory light‑source RRT: Procedures and exposure conditions are aligned with ISO 4892 series:
- Xenon‑arc exposure (according to ISO 4892‑2): specified irradiance/BST or BPT and water spray cycles; sampling at set periods (e.g., 24, 48, 72, 96 h).
- Open‑flame carbon‑arc (ISO 4892‑4) and fluorescent (UVA340, ISO 4892‑3) exposures with defined modes and periods.
- Outdoor exposure: PERS exposed at multiple global sites to characterize combined UV and temperature effects; moisture influence was not determined in the study.
- Limitations: The particular PERS material used in the referenced tests is no longer available; no replacement material was qualified in the report.
Applications
- Monitor and validate laboratory accelerated weathering chambers and light sources for consistency and reproducibility.
- Correlate laboratory exposures to real‑world outdoor weathering by comparing carbonyl index progression.
- Support quality control, inter‑laboratory comparisons (RRT), and method development for plastics weathering studies.
- Useful for material testing of plastics, components intended for outdoor service, and research into photo‑oxidation behavior.
Who uses this standard
- Plastics testing laboratories and technicians
- Material scientists and polymer researchers
- Manufacturers of outdoor plastic products and coatings
- Accreditation bodies and standards committees conducting inter‑laboratory comparisons
Related standards
Keywords: ISO/TR 19032:2019, PERS, polyethylene reference specimens, carbonyl index, weathering tests, accelerated exposure, xenon‑arc, carbon‑arc, fluorescent lamp, outdoor exposure, plastics testing.