In addition to the size and tolerance accuracy, the surface precision of the product should be included (shrinkage, indentation, joint line, gloss, flatness...Etc.),
For plastic products size shrink, levels of high precision injection molding technology, should be at the beginning of the mold design, can according to the size, shape of the products, plastic materials, gate size, flow direction, decided to a very precise shrink law, law and in accordance with the mold size shrink to design, when processing, injection molding, and then according to the environment, the processing of raw materials, processing conditions, determine the best make out products size after shrink, just the required size accuracy, conform to the finished product on the drawing
Low level of precision injection molding technology, is in the mold design can't accurate decision shrink when law, etc, to predict the finished product quality after the injection, can only produce in the future, according to make changes to the products quality conscious, fixed production factors (including the material drying, adjustment of injection condition...The final quality of the product is close to the requirements of the finished product, and it is controlled to achieve this precision every time.