plastic mould and custom injection moulding tips

Plastic Mould Ejection Injection moulding compounds exhibit a certain amount of shrinkage，i.e., in a cooled condition, the volume is somewhat smaller than in a heated condition. If parts with accurate dimensions are needed, allowances must be made for this shrinkage when establishing the dimensions of the cavities. Shrinkage also causes the molded parts to sit tight on the cores since usually parts are ejected after they have cooled down. As a result, extraordinary measures are required to be able to eject finished parts. These measures include, first of all, careful polishing of all mold surfaces that come in contact with the plastics melt as well as a certain draft in the direction of draw. Since self-acting slight lubrication of the mold surfaces that come in contact with the molded parts is possible only in rare cases,there is a danger that scratches and cracks will occur when the mold is opened or the parts ejected, particularly if the molding compound is very hard. A mirror fini

  Mold surface treatment technology In addition to the reasonable cooperation of the steel  strength and toughness, its surface properties are critical to the work performance and service life of the mold. These surface properties refer to: wear resistance, corrosion resistance, friction coefficient, fatigue properties, and the like.  if it only rely on the improvement of steel , the improvement of these properties is very limited and uneconomical. The surface treatment technology can often  receive unexpected results, which is why the surface treatment technology has developed rapidly. The surface treatment of the mold is a systematic project to change the morphology, chemical composition, structure and stress state of the mold surface to obtain the required surface properties. through surface coating, surface modification or composite processing technology can be achieved. From the surface treatment methods, it can be divided into: chemical methods, physical methods, physical and ch