Surface quality and inspection requirements for injection molding

Surface quality and inspection requirements for injection molding:

① The raw material must be fully dry according to the process requirements, without moisture, otherwise there will be silver grain on the surface after injection

② Injection temperature, pressure, time and so on meet the requirements of process parameters card, injection speed should be strictly controlled, too fast injection speed will lead to the adhesion of coating and matrix difference (electroplated parts injection speed control between 15%-35%)

③ In the process of injection molding, can not use release agent, especially containing silicone oil release agent, otherwise it will affect the adhesion of the coating;

(4) The material should be cleaned after the intermediate shutdown to avoid the brittleness of injection products caused by the degradation of raw materials in the screw due to too long residence time;

⑤ The surface of injection molded parts shall not be polished and polished, so as not to affect the adhesion of coating and matrix;

⑥ Operators in the process of injection molding, must bring clean cotton gloves, to avoid the surface of the product after injection molding is polluted;

⑦ internal stress control: the product is not allowed to exist large internal stress, injection molding should be internal stress detection (using glacial acetic acid immersion method) [parts soaked in thick glacial acetic acid for 1-2 minutes, take out water rinsing, and then observe whether the surface has turned white]

⑧ Size control: length, assembly foot or assembly hole in line with the drawings and measuring requirements

Surface quality inspection requirements

The surface should be smooth and smooth, uniform color, no material, clamping, deformation, cracking, color stratification, surface without pitting, shrinkage, flow marks, silver grain, oil spot, scratch, melting wire is less than the limit of the sample. [Clean cotton gloves must be taken for inspection]