Sometimes it is found that after a few days of injection molding, white and other light-colored PVC parts will find many small pits on the surface and have to be scrapped. The reason is related to the order of injection molding production. When producing dark parts such as black or blue, due to hot air [...]
1, Increasing the injection pressure can improve the tensile strength of PP injection molded parts. PP material is more elastic than other rigid plastics. Therefore, the density of injection molded parts will increase with the increase of pressure. This feature is relatively obvious. When the density of plastic parts increases, its tensile strength will naturally [...]
Two injection molded parts that can be assembled and disassembled are commonly known as male parts and female parts. When the injection pressure and injection time of the male part increase, or the injection pressure and injection time of the female part decrease, the outer diameter of the male part increases, the inner diameter of [...]
Due to special functions, some thick-walled transparent injection parts are often encountered during injection molding. Because to performance reasons, these plastic parts use PC as the raw material, and the average wall thickness More than 6mm, the maximum wall thickness exceeds 12mm. For such plastic parts, two problems often occur during injection molding, one is [...]
The shrinkage rate of POM is very large, up to more than 2.5%. Therefore, the size of injection molded parts is also greatly affected by the injection pressure and injection time. When the injection pressure increases or the injection time increases, the size of the injection molded parts will increase. Conversely, when the injection pressure [...]
Sometimes due to defects in mold manufacturing, the appearance shrinkage of the injection molded part at the position of the cylinder (injection pin) is difficult to solve regardless of the adjustment of the machine. Even if it is reluctantly solved, the injection molded parts are already flashing. There are two main reasons for the serious [...]
Large flat plastic parts have a large area, and the shrinkage is also large. Due to the severe molecular orientation of large plastic parts, and the uneven cooling of the mold, the shrinkage of the plastic parts in different directions appears inconsistent, which leads to the phenomenon of deformation and distortion easily after injection molding [...]
Soft plastics are much more flexible than hard plastics. Therefore, the ability of soft plastics to compress and store pressure is much stronger than hard plastics. The reason for the shrinkage problem of injection molded parts is that the space left when the melt condenses and shrinks cannot be replenished by the melt. Since the [...]
1, Two temperature conditions that are not conducive to solving the shrinking problem A, The mold temperature is too high is not conducive to solving the shrinking problem The problem of shrinkage of hard plastic parts (surface shrinkage and internal shrinkage) is due to the defects caused by the shrinkage of the melt, the space [...]
The shrinkage problems of hard plastic parts (surface shrinkage and internal shrinkage) are mostly due to defects caused by insufficient melt supplement when the thicker parts are cooled. It is often the case that increasing the pressure, increasing the gate, and extending the injection time, the shrinkage problem cannot be solved. Among the commonly used [...]
