Volatile Extraction and Titration Frameworks for Recycled Polyolefin Pellets
Coupling thermal desorption solvent extraction with non aqueous potentiometric titration quantifies volatile contaminants and acid values in recycled polyolefins.
Lot Acceptance Criteria
Meaning
Quality assurance clauses located in procurement contracts establish mandatory performance limits for inbound raw material batches. Technical evaluation relies on lot acceptance criteria to determine whether delivered resin lots are accepted into production inventory or quarantined for supplier return. The protocol governs incoming inspection parameters, including melt flow index ranges, moisture percentages, ash content values, and tensile yield strength.
Criteria apply exclusively at the point of receipt prior to hopper loading or melt processing.
Testing Protocol
Standardized laboratory procedures measure physical properties against pre-set standard deviation bounds. Validating lot acceptance criteria requires taking representative core samples from sealed gaylord boxes before releasing the batch to production feed lines. Differential scanning calorimetry verifies peak melting temperatures to confirm polymer identity and virgin resin purity.
Deviations in thermal profile trigger immediate quarantine protocols to protect hot runner systems from un-melted contaminants.
Defect Threshold
Moulding plants establish quantitative limits for allowable particulate contamination and color variance. When testing against lot acceptance criteria indicates contamination above two parts per million, incoming shipments face rejection. Statistical sampling plans define acceptable quality levels to balance producer risk against buyer quality standards.
Material Release
Procurement records document supplier compliance with contracted quality parameters. Authorized release certificates confirm that lot acceptance criteria are met before raw material batches enter active compounding lines. Documentation creates an auditable record connecting incoming raw material lots to finished medical device mouldings.