Injection molding is a method of molding industrial products, products usually use rubber injection molding and plastic injection molding, injection molding can also be divided into injection molding and die-casting method. Injection molding machine is the main equipment for molding thermoplastic or thermosetting plastics into various shapes of plastic products using plastic molding molds. Injection molding is achieved through injection mold maker and molds.
The injection head of an injection mold maker with a gate sleeve on one side is a static mold, which generally consists of a gate sleeve, a backing plate and a template. Simple molds can also be made without using a backing plate, just by using a thicker template. The gate sleeve is generally standard and not recommended for elimination unless there are special reasons.
The use of gating covers facilitates the installation of moulds, which are easy to change without having to polish them by yourself. Some special moulds can be injection moulded by drilling out or cutting with a taper line. When some molds must be de-molded by static mold release, a static mold release mechanism must be added. The construction of the movable mould is generally made up of the movable platen, the movable platen backing plate, the ejector mechanism, the mould feet and the mounting plate.
The gate is directly related to the appearance of the plastic part, if the gate is not well designed, it is easy to produce defects, and it is easy to produce serpentine flow in the absence of any obstruction. For demanding products, overflow and exhaust should be designed as well. A top bar can be used at overflow. Do not leave the overflow fly edge on the template, so as not to affect the service life of the mold.
In addition to the ejector bar, there is also a return bar in the mold release machine. Some moulds also have additional springs for functions such as automatic mold release. There are also guide pillars, cooling water holes, runners and other basic structures that are essential to the mold. Of course, the slanting guide moulds also have slanting guide boxes, slanting guide columns, etc.
When designing a mold for a product, the first step is to set the basic structural dimensions of the mold for material preparation to speed up the mold making process. Complex products should be drawn up first, and then the size of the mold should be set. Nowadays, the tooling is basically heat-treated to increase the hardness of the tooling and improve its service life.
Preliminary processing of the formwork prior to heat treatment: drill the column hole, return hole, cavity hole, screw hole, gate sleeve hole, pull material hole, cooling water hole, etc. Milling of runners, cavities, some molds should be milled with inclined guide boxes, etc.
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