Injection Molded Part Appearance Inspection Quality Standards
Appearance inspection of injection molded parts is a crucial aspect of quality control. The standards are typically based on product application, customer requirements, and industry specifications. The following is a general quality standard for the appearance inspection of injection molded parts, for reference.
I. Inspection Conditions
- Lighting Environment: Under natural light or standard light source, visual inspection distance of 30-50cm, observation time ≤10 seconds.
- Observation Angle: Inspect from multiple directions at a 45°-90° angle to avoid glare interference.
II. Common Defect Judgment Standards
1. Sink Marks: Slight sink marks are allowed on non-visible surfaces (depth ≤0.1mm); no obvious sink marks are allowed on visible surfaces.
2. Weld Lines: Allowed in non-critical areas, but must not affect strength; weld line length on visible surfaces ≤5mm and without color difference.
3. Flow Marks: No obvious flow lines are allowed (must be eliminated through mold temperature or process optimization).
4. Bubbles: Surface bubble diameter ≤0.3mm, and no more than 3 bubbles per 100cm².
5. Scratches/Abrasions: Length ≤5mm, depth should not reach the base material color (to be adjusted according to customer requirements).
III. Color and Gloss
1. Color Difference: Must be compared with the standard color sample, ΔE≤1.5 (or according to customer requirements).
2. Uneven Gloss: No obvious differences are allowed on visible surfaces; slight differences are acceptable on non-visible surfaces.
IV. Structural Defects
1. Burrs/Flash: Edge burr height ≤0.1mm, and no sharp edges are allowed.
2. Short Shots: No short shots or insufficient filling are allowed in any part.
3. Deformation: Within the assembly dimensions, warpage deformation ≤0.2% of the product length.