Quality Control in Underwear Manufacturing: AQL Standards and Inspection Process
Underwear quality control uses AQL 2.5 (major defects) and AQL 4.0 (minor defects) standards. Testing happens at three stages: inline during production (30-60-90% completion), final random inspection before packing, and container loading supervision for quantity and labeling accuracy.
Quality control separates professional OEM suppliers from unreliable manufacturers. Understanding AQL standards and the inspection process helps buyers ensure consistent product quality. Here’s how Unitex quality control works at every stage.
What is AQL?
Key Insight: Underwear quality control uses AQL 2.5 (major defects) and AQL 4.0 (minor defects) standards per ISO 2859-1. Testing occurs at three stages: inline during production (30% completion checks construction, 60% checks seam quality, 90% checks finishing), final random inspection (200 pieces from 10,000-unit lot), and container loading supervision (quantity verification, carton labeling, moisture indicators). Critical defects — metal fragments, broken needles, choking hazards — trigger automatic lot rejection regardless of AQL sample results. QC standards →
AQL (Acceptable Quality Level) defines the maximum number of defective units allowed in a sample batch. For underwear, the industry standard is AQL 2.5 (Major defects) and AQL 4.0 (Minor defects). Major defects include seam breaks and size deviations over 5%. Minor defects include loose threads and slight color variation.
Three-Stage Inspection
- Inline Inspection (DPI): During production, 100% of critical seams and elastics are checked.
- Final Random Inspection (FRI): AQL 2.5 sampling after production is complete.
- Loading Supervision: Container loading verification for correct quantities, packaging, and labeling.
Common Underwear Defects
Seam puckering, twisted leg openings, elastic failure, color shading between panels, and sizing inconsistency are the most frequent issues. Our inline inspection catches 95%+ of defects before final inspection.
Third-Party Inspection
Buyers can commission independent inspection companies (SGS, Bureau Veritas, Intertek) for additional verification. We welcome third-party inspection at any stage. Contact Unitex for QC documentation.
Unitex is based in Xiamen, Fujian Province, and develops these programmes with audited partner factories across the Xiamen–Quanzhou–Jinjiang knitwear cluster of south-east China.
· Xiamen Unitex Trade Co., Ltd. — OEM & ODM underwear sourcing partner