Meaning
International technical standards establish the designation system, classification parameters and property characterization bases for polyethylene moulding and extrusion materials. The standard ISO 17855 defines a standardized data-block coding structure that categorizes polyethylene resins based on density, melt mass-flow rate and intended processing application. It provides the global framework used on technical datasheets and procurement contracts to specify prime, recycled and modified ethylene-based polymers.
The standard governs raw resin classification and stops applying once the polymer is processed into finished moulded parts or extruded structural shapes.
Designation Structure
Material classification follows a systematic alphanumeric data-block architecture that communicates primary resin attributes without ambiguity. Under ISO 17855, the designation records polymer type, specific chemical modifications, presence of additives, density range and melt mass-flow rate measured under standard temperature and load conditions. Data Block 1 identifies the chemical nature of the polymer, distinguishing homopolymers from ethylene-hexene or ethylene-octene copolymers.
Subsequent data blocks specify processing methods, such as injection moulding, film blowing or blow moulding, alongside targeted performance additives like slip agents, antioxidants and UV stabilizers.
Property Categorization
Precise property ranges define the resin classification codes used by polymer chemists and procurement engineers globally. The framework of ISO 17855 classifies polyethylene density into specific cell ranges determined in accordance with ISO 1183, separating low-density materials below 0.918 grams per cubic centimeter from high-density grades exceeding 0.940 grams per cubic centimeter. The melt mass-flow rate is coded according to standard testing parameters at one hundred and ninety degrees Celsius under a two point one six kilogram load.
These standardized property brackets ensure that resin buyers can cross-reference equivalent polymer grades across international resin producers with complete technical precision.
Procurement Execution
Material specifications on engineering drawings and purchasing orders utilize this standardized designation system to eliminate ambiguity in raw material sourcing. Citing ISO 17855 ensures that compounding facilities and contract injection moulders procure resin grades with identical rheological and mechanical properties across different global manufacturing sites. A change in the resin designation code alerts moulders to potential variations in mould shrinkage, cycle times and mechanical part performance.
The standard provides the international baseline for quality assurance, material compliance testing and commercial technical agreements across the plastics processing sector.
