Plastic products are produced on special injection molding devices that are used in injection molding and are called injection molding machines. The main part of these machines is the mold in which the future part is formed. A mold is a special device that contains a cavity for plastic powder, where, under high pressure and temperature, the material is formed into a developed part.
The process of making plastic injection molds requires the involvement of experienced engineers. Indeed, to create these devices, it is necessary to develop design documentation for the manufactured part and the mold itself. This package of documents includes a full description of the devices being developed, their drawings, and a 3d model.
Types of mold designs for molding plastic products
There are two types of molds: direct pressing and injection molding. The structure of the first type consists of two working plates, between which a special cavity is created. Polymer is fed into it through special channels called sprues. One of the plates is called a matrix; it has special cavities that correspond to the design of the product being developed. The polymer gets into the matrix under the action of high pressure and the future of the product is already formed in it. Also in this type of molds there is a punch - a movable part of the device. With the help of which the received part is extracted from the injection molding machine.
The second type mold consists of three plates. And the main distinguishing feature from the first type is that the matrix and sprues are located independently of each other. This advantage makes it possible to design parts of a wide variety of sizes, which makes such a mold multifunctional. Many companies are engaged in the production of the second type of these devices.
The main stage in the creation of injection molds is design. At this stage, design documentation for the device and the future product is developed, calculations are carried out in special computer programs, a drawing and a three-dimensional model of the mold are developed. Based on this data, the customer can see how the future product will look, and, if necessary, can make adjustments before production starts.
Another important one in the manufacture of molds is the system for feeding molten polymers into the matrix and is called the gating system. There are two types: hot runner and cold runner. The first type of injection mold is more difficult to manufacture, but using it there will be less waste. The second type is easier to manufacture, cheaper in cost and more reliable to operate during production.
Article source: http://moldstar.ru/uslugi/litye-plastmass-pod-davleniem
