![]() ![]() PET plastic needs good plasticizing ability and suitable screw compression ratio design to have a good molding effect. The number of mold cavities (one mold several cavities) should be considered when calculating the weight of the finished product įor the sake of stability, the injection volume should be more than 1.35 times the weight of the finished product, that is, the weight of the finished product should be within 75% of the injection volume.Ĭonditions such as "screw compression ratio" and "injection pressure" are determined from PET plastic. Preliminarily determine the specifications of the clamping unit and roughly determine the tonnage of the PET machine, and then the following steps must be performed to confirm which injection unit has a more suitable screw diameter.ĭetermine the required "shot volume" and select the appropriate "screw diameter" based on the weight of the finished product and the number of cavities. The clamping force of the machine needs to be greater than the force of the die, and for the sake of safety, the clamping force of the machine usually needs to be more than 1.17 times the force of the die. Supporting mold force = projected area of the finished product in the direction of opening and closing the mold (cm2) × number of mold cavities × pressure in the mold (kg/cm2) The clamping force requirement is calculated as follows:Ĭalculate the projected area of the finished product in the direction of the opening and closing die from the appearance size of the finished product When the raw material is injected into the mold cavity under high pressure, a mold-pulling force will be generated, so the clamping unit of the injection molding machine must provide enough clamping force to prevent the mold from being stretched. ![]() The tonnage of the clamping force of the machine is determined by the product and the plastic. ![]() The pallet stroke and pallet force should be sufficient to eject the finished product. ![]() The mold opening stroke must be at least twice the height of the finished product in the direction of mold opening and closing It is determined by the mold and the finished product whether the mold opening stroke and the mold supporting stroke are sufficient for the finished product to be taken out. The width and height of the mold must conform to the minimum mold size recommended by the PET injection molding machine. The thickness of the mold needs to be between the mold thickness of the injection molding machine The width and height of the mold should preferably be within the size of the template The width and height of the mold must be smaller than or at least one side is smaller than the inner distance of the large column The inner distance of the large column, the thickness of the mold, the minimum size of the mold and the size of the template are determined by the size of the mold to confirm whether the mold can be placed. The larger the aspect ratio, the better the plasticizing ability. The aspect ratio of PET screw is generally above 1:24. Generally, the aspect ratio of plastic screw is about 18-22. According to the characteristics of PET plastic, we choose PET injection molding machine from the following aspects:įor screw aspect ratio, special PET screw is designed. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |