Overview
EN ISO 3673-1:1999 (ISO 3673-1:1996) defines a standardized method of designation for epoxy resins. Its purpose is to assign each commercial epoxy resin a concise coded name that conveys essential information - chemical base, main property ranges and the nature of modifiers, solvents or additives. The designation helps users compare products and choose appropriate materials when manufacturers include the code on technical data sheets.
Key topics and requirements
- Designation format: Resins are identified by the symbol EP followed by a group of five digits (principal properties), a space and three digits (secondary properties).
- The first two digits (taken together) indicate the chemical base (e.g., bisphenol A glycidyl ethers, aliphatic glycidyl ethers, novolac, halogenated epoxides, etc.).
- Subsequent single digits encode viscosity, epoxy equivalent, density, and additives/modifiers classes according to defined ranges.
- A lowercase x may be used if a property is not specified.
- Property references and test methods: The standard refers to established ISO test methods for property classification, notably:
- Classification principle: Each digit denotes a class (1, 2, 3, …) corresponding to a range of values for that property. The designation represents mean manufacturing values normally reported on data sheets; tolerances and exact measurement procedures must be supplied by the manufacturer.
- Example: EP 03361 3xx (from the standard) decodes to an aliphatic glycidyl ether base, viscosity 1–5 Pa·s, epoxy equivalent 291–525 g·mol⁻¹, density 1.15–1.19 g·cm⁻³, no modifiers specified, with unspecified secondary digits.
Applications and users
- Who uses it: resin manufacturers, formulators, material specifiers, procurement teams, testing laboratories and standards committees benefit from a uniform, searchable designation for product comparison and specification.
- Practical value:
- Speeds selection of epoxy resins for adhesives, coatings, laminates, composites and electrical applications by grouping similar materials.
- Improves clarity in datasheets and procurement documents.
- Facilitates regulatory reporting and cross-referencing between suppliers.
Related standards
Keywords: EN ISO 3673-1:1999, ISO 3673-1:1996, epoxy resin designation, EP designation, epoxy equivalent, viscosity, density, epoxy additives, thermosetting materials.
