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1) What is an insert? It is an irregular mold accessory specially used for inlaying in the mold. Insert is a general term, in the mold, it is an irregular mold accessory specially used for inlaying in the mold, which plays the role of fixing the template and filling the space between the template. The inserts can be square, round, and sheet-shaped, and like all mold accessories, the requirements for precision are very high. Generally, there is no finished product, and it is customized according to the needs of the mold. 2) What is a plastic insert? When the injection molded part is required to contain other parts that have been processed, it is most reliable to use the form of inserting in the mold, because in this way, the part of the pre-processed part for fixing is completely covered by plastic. Usually we see plugs containing copper cores, including plastic iron chips, etc., which are all in this form. In die-casting molds, there are also parts in this form, such as parts in the steering wheel of a car. And when we require two kinds of materials with different properties or colors to achieve special appearance or use requirements for injection molded parts, we will also use one of the materials to be molded first, and then put it into the injection mold of the other material. The method of molding together, in fact, two-color or multi-color injection molding basically applies this principle. Then the part that is formed first is called a plastic insert. Such molds have difficulties in controlling mold temperature, affecting the fluidity of plastics, difficult positioning of inserts, high requirements for mold clamping accuracy, and low production efficiency. If you are using metal inserts, it may be necessary to preheat the insert to ensure a uniform temperature in the cavity, while for plastic inserts the mold temperature must be below the heat distortion temperature of the insert. For metal inserts, the positioning part should consider the wear caused by repeated insertion and removal of metal inserts, while for plastic inserts, it is necessary to consider that the inserts cannot be improperly deformed due to inaccurate positioning. . 3) What is the need for inserts: 1. Save materials. The setting of the rear mold is determined by the highest point. If there is only a single place with a relatively regular shape, this piece can be set up, so that when the material is fixed, it can be set short. 2. It is convenient to process. Among the equipment for mold processing, EDM has the slowest speed and the worst accuracy, so sometimes in order to avoid EDM processing as much as possible, inserts are chosen. 3. Convenient exhaust. Especially for some deep bone positions, EDM processing has poor drainage and poor exhaust during molding, and inserts are often required at this time. 4. Guaranteed accuracy. The grinding machine has the highest processing accuracy. Sometimes, in order to ensure the precision of Sino mold, the convenient grinding machine processing shall prevail. 5. Interchange requirements. Sometimes customers require the same product, such as changing the label position, to do interchangeable inserts. 6. easy to save mold. In some deep positions, it is quite inconvenient to save the mold, so it is made into an insert. 7. easy to change the mold. Some positions are easy to wear or the precision requirements are too high. For the consideration of mold modification, they are made into inserts. 8. heat dissipation considerations. This mainly refers to beryllium copper inserts. 4) Process steps of plastic inserts The first step: the selection of inserts. 1. The selection of the insert material cannot be selected so that the heat distortion temperature is lower than the mold temperature required for the injection molding of the main material, and there should be an appropriate margin; 2. The compatibility between the insert and the main material, if the compatibility is not good, it will affect the bonding strength of the two materials; 3. Again, it is the mechanical strength of the selected insert material. For inserts with appearance requirements, they cannot be deformed due to the injection pressure during the injection molding process of the main body; 4. Whether the material of the insert will cause inappropriate flow resistance to the material of the main body, so that the molding of the main body will encounter undue difficulties. There are other requirements in the selection of materials. The above are the main ones in terms of art. In many cases, these requirements are opposite. Only through comparative analysis can a balanced solution be found, and sometimes it is even required to improve the main mold. . Step 2: Dimensions of the inserts. 1. The size of the insert should meet its own molding requirements; 2. Considering the environment in which the insert is placed when the main body is injection molded, if the insert is a combination of lines, these lines must have sufficient strength to withstand the injection pressure (sometimes it may be required to increase the line width); 3. If there is a filling area in the insert, the injection molding process requirements of the main body must be considered.