{"id":"wpc-tech100-article-071-en","slug":"density-mapping-and-void-detection-in-wpc","locale":"en","url":"https://woodplasticcomposite.net/guides/density-mapping-and-void-detection-in-wpc/","title":"Density mapping and void detection in WPC","answer":"A single average density can conceal local variation in a composite profile. Density and void investigations should be designed around the suspected defect and the geometry being inspected.","author":"NFC & WPC Knowledge Reference","faqIds":["wpc-tech100-faq-071-en"],"tagIds":[],"noindex":false,"related":["wpc-tech100-article-072-en"],"version":1,"modified":"2026-10-15","reviewer":"","sections":[{"id":"technical-context","text":"A low result can have several explanations, including intended cellular structure, an incorrect reference density or unwanted voids. It should not automatically be labelled poor quality without understanding the product design.","heading":"Technical context","references":[],"url":"https://woodplasticcomposite.net/guides/density-mapping-and-void-detection-in-wpc/#technical-context"},{"id":"verification-plan","text":"Use a consistent method and record the sampled locations. Combine mass and dimensional measurements with suitable imaging or section inspection where necessary. Check whether preparation, moisture or surface features affect the calculation.","heading":"What to measure and document","references":[],"url":"https://woodplasticcomposite.net/guides/density-mapping-and-void-detection-in-wpc/#verification-plan"},{"id":"practical-decision","text":"Set acceptance criteria against the qualified product, not against an assumed ideal solid. Hollow, foamed and solid profiles require different interpretations. The purpose is to detect departures from the intended structure and link them to relevant performance.","heading":"Implications for development and specification","references":[],"url":"https://woodplasticcomposite.net/guides/density-mapping-and-void-detection-in-wpc/#practical-decision"},{"id":"reading-scope","text":"A research investigation using imaging and microscopy to examine exposed WPC samples. 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/density-mapping-and-void-detection-in-wpc/#reading-scope"}],"seoTitle":"Density mapping and void detection in WPC | 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":"A low result can have several explanations, including intended cellular structure, an incorrect reference density or unwanted voids.\nUse a consistent method and record the sampled locations.\nSet acceptance criteria against the qualified product, not against an assumed ideal solid.","aiAssisted":true,"categoryId":"wpc-tech100-category-3","reviewedAt":"","change_note":"New focused technical draft; not a product certification or production recipe.","description":"A single average density can conceal local variation in a composite profile.","heroImageId":"","referenceIds":["wpc-tech100-ref-imaging"],"review_status":"AI-assisted English editorial draft. Human technical review has not been recorded.","table_caption":"Evidence checklist for density mapping and void detection in wpc","seoDescription":"A single average density can conceal local variation in a composite profile.","translationGroup":"wpc-tech100-071-2026","references":[{"url":"https://research.fs.usda.gov/treesearch/46176","type":"web","title":"Instrumental methods for studying biological decay in WPC","noindex":false,"accessed":"2026-10-14","seoTitle":"Instrumental methods for studying biological decay in WPC","publisher":"USDA Forest Service","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 density mapping and void detection in WPC?","answer":"Use a consistent method and record the sampled locations. Combine mass and dimensional measurements with suitable imaging or section inspection where necessary. Check whether preparation, moisture or surface features affect the calculation."}]}