Plastic product quality inspection method

This standard mainly stipulates the inspection and test methods of various plastic products produced by injection molding. It is applicable to the inspection of general ‎‎HDPE Plastic Injection Molding Manufacturer. This standard is only for routine inspection. Special requirements shall be subject to PARTSPEC.

Explanation of common defects 1 Scorch marks (RURNS): material decomposition caused by heat.
2 Discoloration (DISCOLORATION): deviation from the original color or inconsistent color.
3 Flowmarks (FLOWMARKS): stripes like dry river channels formed by the flow of plastic parts.
4 Haze (HAZE): hazy points or areas formed on the surface of clear materials.
5 PITS: small pits or surface material shortages.
6 PROTRUSIONS: points or surfaces higher than the surface of the surrounding materials.
7 SCRATCHES: small grooves or points or surfaces cut into the surface of the material.
8 SINKMARKS: surface shrinkage or small sink marks.
9 Spots (SPECKS): Small particles or impurities on the surface or inside.
10 Weldlines (WELDLINES): Visible lines (traces) formed when the front end of the cold material on the plastic surface is welded together.
11 Measuring surface: Observed surface First measuring surface: Top surface or side surface that users often see Second measuring surface: Side, corner or edge position that users see occasionally or rarely see. Third measuring surface: Bottom surface of assembly parts, components, parts or surface of parts that are attached to each other during assembly.

2. Inspection conditions This standard is based on the premise that there is no impact on the function and relies on visual comparison, so it is not better than the limit sample and individual special standards. Usually visual inspection is performed at 30cm for 3 to 5 seconds. If defects are found, move to 50cm for observation for 3 to 7 seconds. It is OK if it is difficult to see and not too obvious. 2.3 The detection light source is the fluorescent lamp of the production factory, and the vision is above 0.7. 2.4 Observation angle: perpendicular to the observed surface and 45 degrees above and below.

3. Technical requirements and inspection methods Surface (appearance) quality Defects First measuring surface Second measuring surface Third measuring surface Inspection method 1 Cracks are not allowed. When there is no impact on the appearance and performance of the assembled finished product, it is allowed to have glue slip. It does not affect the appearance and assembly function, and it is slightly acceptable. Visual inspection (trial assembly) 3 Water marks are based on the engineering sample as the lowest standard (for the board) 4 Shrinkage is based on the engineering sample as the lowest standard. There is no obvious water mark when viewed from 45 degrees to 90 degrees, and there is no dent when touched. Same as left Same as left Visual inspection or touching the product with your hand to see the depth of the dent at the shrinkage of the board 5 Edge dragging is not allowed. It is not obvious when viewed from the outside. It is allowed to have visual inspection 6 Miscellaneous spots (black spots) Mixed color stains The accumulation of these 3 defects cannot exceed 4 points, and 3 points cannot be concentrated. The separation should be greater than 100mm. The area of ​​each point of the miscellaneous spots/stains/mixed colors is not greater than 0.4mm2. The accumulation of these 3 defects cannot exceed 6 points, and 3 points cannot be concentrated.

The separation should be greater than 100mm. The area of ​​each point of the miscellaneous spots/stains/mixed colors is not greater than 0.5mm2. The accumulation of these 3 defects cannot exceed 9 points, and 3 points cannot be concentrated. The separation should be greater than 100mm. The area of ​​each point of the miscellaneous spots/stains/mixed colors is not greater than 0.9mm2. Eye test 7. Flower marks and bumps. The length of each flower mark/bump is not greater than 8mm, and the width is not greater than 0.05mm. The length of each flower mark/bump is not greater than 10mm, and the width is not greater than 0.1mm. The length of each flower mark/bump is not greater than 2.5mm, and the width is not greater than 0.15mm. Eye test 8. White is not allowed. Not allowed. Does not affect the appearance. Acceptable, but cannot be raised to affect the function. Eye test Routine Inspection Standards for Injection Molding Product Quality 3.2 Functional Quality 3.2.1 Peaking – Any speaker hole, button hole, switch hole and all matching holes of moving parts shall not have peaking, and the peaking of built-in column and bone positions shall not affect assembly and function; the peaking that is exposed or may be exposed (such as: battery door) and affects safety shall not feel scratchy when touched. 3.2.2 Deformation – The deformation of the bottom shell supported on the platform shall not exceed 0.3mm, and the deformation of the surface shell matched with the bottom shell supported on the platform shall not exceed 0.3mm. The deformation of other plastic parts is acceptable as long as it does not affect the assembly function. 3.2.3 Dimensions – Dimension requirements are in accordance with PARTSPEC. When there is no SPEC, refer to the sample and control according to the following tolerance requirements: Rubber part size range Rubber part tolerance value (so as not to affect the assembly function)　　　　Unit: mm0-10±0.0510.1-50±0.1050.1-100±0.15100.1-200±0.20200 and above ±0.25 3.2.4 Residual glue at sprue – a) The sprue position that is exposed or may be exposed (for example: battery door) and will affect the appearance and safety standards should be flat and meet safety standards and cannot scratch hands. ——b) There are assembly requirements but it cannot be exposed. The residual glue at the sprue that does not affect the assembly should be controlled within 0.5mm and not affect the function. ——c) There are no assembly requirements, the function is not affected, and the sprue is not exposed. The size is controlled within 1.5mm, and the fracture shape of the sprue position can be in a free state.