{"id":"wpc-tech100-article-028-en","slug":"screening-recycled-polymer-for-unwanted-inclusions","locale":"en","url":"https://woodplasticcomposite.net/guides/screening-recycled-polymer-for-unwanted-inclusions/","title":"Screening recycled polymer for unwanted inclusions","answer":"Recycled polymer quality depends on what enters the stream as well as the named resin. A WPC feedstock plan should address incompatible plastics, metal, grit and other unwanted inclusions explicitly.","author":"NFC & WPC Knowledge Reference","faqIds":["wpc-tech100-faq-028-en"],"tagIds":[],"noindex":false,"related":["wpc-tech100-article-029-en"],"version":1,"modified":"2026-10-15","reviewer":"","sections":[{"id":"technical-context","text":"One clean-looking sample does not establish batch consistency. Some contaminants may be visible while others require analytical checks. Sorting and filtration claims should therefore be translated into measurable acceptance criteria rather than treated as complete guarantees.","heading":"Technical context","references":[],"url":"https://woodplasticcomposite.net/guides/screening-recycled-polymer-for-unwanted-inclusions/#technical-context"},{"id":"verification-plan","text":"Agree sampling locations, retained samples and escalation rules with the supplier. Match screening methods to plausible contaminants and the intended process. Quarantine a suspect lot while the cause is investigated instead of diluting uncertainty into accepted material.","heading":"What to measure and document","references":[],"url":"https://woodplasticcomposite.net/guides/screening-recycled-polymer-for-unwanted-inclusions/#verification-plan"},{"id":"practical-decision","text":"Contamination control supports reliable production and traceability; it does not by itself prove a product environmentally preferable. Keep recycled-content claims, feedstock quality and finished-product performance as related but separate parts of the purchasing evidence.","heading":"Implications for development and specification","references":[],"url":"https://woodplasticcomposite.net/guides/screening-recycled-polymer-for-unwanted-inclusions/#practical-decision"},{"id":"reading-scope","text":"Official guidance on controlling measurement processes and supporting uncertainty statements. Use the linked work as related reading. The practical checks above are editorial recommendations, not reported test results or a substitute for product qualification.","heading":"Related reading and evidence limits","references":[1],"url":"https://woodplasticcomposite.net/guides/screening-recycled-polymer-for-unwanted-inclusions/#reading-scope"}],"seoTitle":"Screening recycled polymer for unwanted inclusions | WPC Reference","topicIds":[],"published":"2026-10-15","tableText":"Review step | Evidence to retain\nMaterial and geometry | Exact specimen or product identity\nVerification | Method, conditions and individual observations\nDecision | Approved scope and documented limitations","takeaways":"One clean-looking sample does not establish batch consistency.\nAgree sampling locations, retained samples and escalation rules with the supplier.\nContamination control supports reliable production and traceability; it does not by itself prove a product environmentally preferable.","aiAssisted":true,"categoryId":"wpc-tech100-category-2","reviewedAt":"","change_note":"New focused technical draft; not a product certification or production recipe.","description":"Recycled polymer quality depends on what enters the stream as well as the named resin.","heroImageId":"","referenceIds":["wpc-tech100-ref-measurement"],"review_status":"AI-assisted English editorial draft. Human technical review has not been recorded.","table_caption":"Evidence checklist for screening recycled polymer for unwanted inclusions","seoDescription":"Recycled polymer quality depends on what enters the stream as well as the named resin.","translationGroup":"wpc-tech100-028-2026","references":[{"url":"https://www.itl.nist.gov/div898/handbook/mpc/section2/mpc2.htm","type":"web","title":"NIST: statistical control of measurement processes","noindex":false,"accessed":"2026-10-14","seoTitle":"NIST: statistical control of measurement processes","publisher":"NIST","description":"Related reading; scope and limitations are identified in each article.","seoDescription":"Related reading; scope and limitations are identified in each article."}],"faqs":[{"question":"What evidence is needed for screening recycled polymer for unwanted inclusions?","answer":"Agree sampling locations, retained samples and escalation rules with the supplier. Match screening methods to plausible contaminants and the intended process. Quarantine a suspect lot while the cause is investigated instead of diluting uncertainty into accepted material."}]}