Nondestructive Computed Tomography Volumetric Void Acceptance Criteria for Heavy Polymer Sections
Computed tomography volumetric void acceptance requires zoning heavy polymer walls by stress field, setting pore limits below 0.1% in tensile skins.
Quality Zonation
Meaning
Quality specification framework documentation divides a component drawing into distinct functional regions with tailored defect size allowances and inspection rigor based on localized operational stress. Application of quality zonation establishes region-specific acceptance limits for internal voids, surface sink marks, and dimensional variations on engineering drawings. The practice governs localized defect size thresholds, inspection resolution requirements, and quality signoff criteria across varying part zones.
Its application stops at multi-zone functional parts, applying no variable criteria to uniform single-tolerance specifications or non-critical single-surface parts.
Zone Assignment
Structural engineering blueprints classifying components into distinct quality regions optimize non-destructive inspection costs and scrap rates. Establishing quality zonation maps ensures that critical sealing surfaces and high-stress bolt bosses undergo rigorous volumetric scanning while low-stress covers receive standard checks.
Tolerance Boundary
Uniform defect limits force unnecessary part rejections when tiny cosmetic micro-voids occur in non-structural outer flanges. Utilizing quality zonation allows non-destructive testing software to evaluate void sizes against localized stress maps generated during finite element analysis. A void that triggers immediate rejection in a highly stressed load-bearing rib is permitted within non-functional cosmetic zones under established engineering standards.
Clear zonation boundaries prevent misinterpretation between polymer moulders and end-use quality inspectors during tool signoff audits.
Inspection Efficiency
Unrealistic zero-defect standards across full part volumes elevate scrap rates and increase CT scan inspection times without adding functional reliability. Adopting quality zonation rationalizes quality signoffs by focusing inspection precision on high-risk functional features.