Overview
ISO 12418-2:2012 - Plastics - Post-consumer poly(ethylene terephthalate) (PET) bottle recyclates - Part 2: Preparation of test specimens and determination of properties - defines the test methods and sample preparation procedures used to determine the physical and chemical properties of post-consumer PET recyclates (flakes, pellets or powder). It is Part 2 of the ISO 12418 series and is intended to support consistent quality assessment, reporting and acceptance of recycled PET for further processing.
Key topics and technical requirements
- Scope and purpose: Specifies which test methods to use when characterizing post-consumer PET bottle recyclates and the information suppliers should provide (e.g., certificate of analysis, sampling method, number of replicates).
- Mandatory characteristics: Includes form, colour, maximum flake/pellet size, intrinsic viscosity (IV) (ISO 1628-5 with specified solvent), contamination levels (labels, PVC, polyolefins) determined by the Annex A procedure, water content (ISO 15512:2008 Method B) and bulk density (Annex B).
- Impurity determination (Annex A): Visual separation and heat-treatment at 220 °C for 1 h to identify labels, PVC (carbonized), and polyolefins/adhesives (yellowish), with results reported in mg/kg.
- Bulk density (Annex B): Fill a container of known volume, level and weigh to calculate kg/m3 from three determinations.
- Melt volume‑flow rate (MVR) (Annex C, informative): Follows ISO 1133 guidance - drying PET at 160 °C for 4 h, test temperature 280 °C, specified die sizes, preforming and charging procedures; includes a log(MVR) ↔ IV conversion note (specific correlations recommended for each recyclate source).
- Residual alkalinity (Annex D, informative): Potentiometric method by stirring 100 g sample in 500 ml distilled water for 10 min and measuring pH.
- Reporting and traceability: Test reports must reference ISO 12418-2, include sample identification, test conditions, results and date.
Applications
- Quality control and acceptance testing of post-consumer PET for mechanical recycling and reprocessing.
- Supplier–purchaser specifications and batch certification (certificate of analysis).
- Laboratory standard operating procedures for materials testing.
- Regulatory compliance and recycling program validation where consistent characterization of PET recyclates is required.
Who should use this standard
- PET recyclers and material suppliers
- Plastics processors and converters using recycled PET
- Quality assurance and testing laboratories
- Procurement/specification engineers and standards writers
- Regulatory bodies and sustainability auditors
Related standards
Keywords: ISO 12418-2, PET recyclates, post-consumer PET, intrinsic viscosity, MVR, bulk density, contamination testing, test methods, plastic recycling.
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