Plastic products require consistent material properties, dimensional accuracy, and surface finish. Defects like warping, flash, short shots, and contamination affect both function and appearance. For food-contact plastics, migration testing is mandatory.
The plastics industry uses AQL 1.0 to 4.0. Injection moulded precision parts may require tighter levels, while commodity items like bags and films typically use AQL 2.5 to 4.0.
| Defect Type | AQL | Inspection Level | Notes |
|---|---|---|---|
| Critical (contamination, food contact) | 0.65 | General II | Migration testing required |
| Major (dimension, warping, function) | 1.5 | General II | CMM measurement |
| Minor (surface marks, flash) | 4.0 | General I | Visual acceptance criteria |
Incoming inspection at AQL 0.65 detected black specks in a batch of food-grade PE granules. The contaminated lot was rejected, preventing production of 200,000 non-compliant food containers.
AQL 1.5 inspection with CMM confirmed that injection moulded closures met the 0.05mm tolerance, ensuring compatibility with the automated capping line.
Skipped inspection allowed warped plastic trays to reach the client. The trays would not stack correctly, causing 15,000 units of product damage and a $200,000 claim.
