Overview
ISO 20568-1:2017 - Plastics - Fluoropolymer dispersions and moulding and extrusion materials - Part 1: Designation system and basis for specifications - defines a standardized system to identify and classify fluoropolymer materials. The standard establishes a clear, machine- and human-readable designation pattern that can be used as the basis for material specifications across supply chains, quality control and procurement for PTFE and other fluoropolymers.
Key topics and technical requirements
- Designation structure: A standardized pattern comprising an identity block (standard number) and an individual-item block subdivided into five data blocks (1–5). Data blocks are separated by commas; unused blocks are indicated by empty entries.
- Data block 1 - Polymer identification: Uses ISO 1043-1 abbreviations plus additional codes (e.g., PTFE, FEP, PFA, PVDF, ETFE, PCTFE, VDF/TFE) and modifiers (homopolymer, copolymer, dispersion, presintered, reprocessed, etc.).
- Data block 2 - Fillers/reinforcing materials: Codes for filler type and form (e.g., glass fibres, carbon, mica) and nominal mass fraction (two-figure percentage).
- Data block 3 - Intended application / processing / additives: Position 1 indicates processing or application (injection moulding, extrusion, tape manufacture, cable coating, etc.); positions 2–8 capture properties/additives (colour, stabilizers, flame retardance, food contact suitability, etc.).
- Data block 4 - Designatory properties: Fluoropolymer-specific properties (varies by polymer). Examples specified in the standard:
- For PTFE granular and resin: standard specific gravity (SSG), bulk density, particle size
- For PTFE dispersions: PTFE % in dispersion, surfactant % and tolerance
- For melt-processable resins (FEP, PFA, PVDF, ETFE, etc.): melting-peak temperature, melt mass‑flow rate (MFR)
- For PCTFE: zero-strength time (ZST); for TFE/PDD: glass transition temperature (Tg)
- Data block 5 - Specification details: For formal specifications, this block contains required tolerances, test methods and extra performance criteria.
- Scope limitations: The standard defines designation and basis for specifications but does not provide engineering performance data or processing conditions; test methods and specimen preparation are referenced in ISO 20568-2 and other normative documents.
Applications and practical value
- Enables consistent material identification across manufacturers, compounders and end-users.
- Supports procurement, material traceability, regulatory declarations (e.g., food contact, high-purity grades) and quality control.
- Useful when specifying grades for injection moulding, extrusion, coating, tapes, tubing, or sintering applications.
- Facilitates communication about blends, filled compounds and recycled content.
Who uses this standard
- Material suppliers and compounders, OEMs specifying fluoropolymer parts, quality and compliance engineers, test laboratories, and standards writers.
Related standards
Keywords: ISO 20568-1:2017, fluoropolymer dispersions, PTFE designation, melt-processable fluoropolymers, material specification, fluoropolymer moulding and extrusion.