Injection processing large area planar member, also a large amount of shrinkage. As the molecular alignment of a large injection molded parts extremely serious, with cooled mold is not uniform, so that the shrinkage in each direction inconsistent molded parts, resulting in a large flat thin molded part is very easy deformation and distortion phenomenon. Sometimes a large flat side of the injection member is designed with a support bone, when the injection molded parts must also bend towards the bone side.
　　To solve the problem of large flat injection molding deformation is indeed a problem, in production we summarize some of the more effective measures to improve the deformation problems:
　　A mold into a multi-point into the water (usually three-plate mold), above 24 An injection molding machine large flat preferably more than 4:00. This can reduce the degree of alignment of the molecules, to reduce the gap between the respective shrinkage inconsistent.
　　2. Appropriate mold temperature, ABS materials typically maintained above 60 ℃, to reduce the cooling rate of the molded part, reduce the temperature difference due to deformation caused by the transition quench, while reducing the degree of molecular alignment.
　　III. The most important one is to increase the plastic injection pressure or holding pressure, and greatly extend the time of injection plastic or packing, the size of injection molded parts is increased, which decreases the amount of shrinkage, the extent of deformation therefore It has been significantly improved. Therefore, the extension of time shooting rubber or holding pressure (such as extended 10-15 seconds), has become an important means to solve the deformation problem common.
　　IV. If the above three measures fail to achieve the desired results, taking only way out of the mold shape. Because most people use is not very good, so a bit tricky.
　　First of all, to advance out of the mold injection molding parts, and then take the next state that is still in the tens degree heat (should still be very hot, it is very critical), setting jig on the table, the key is shaping fixture the design requires appropriate. Also to be considered is the extent of resilient injection-molded part, will rebound substantially stopped generally after 12 hours, and the mold temperature is lower the greater the amount of springback. The so-called righting a wrong to be too positive, so the time to study the production of pressure over a positive amount.