The working principle of a zipper machine is similar to that of a syringe used for injection. It uses the thrust of a screw (or plunger) to inject melted plastic that has already been plasticized (i.e. viscous state) into a closed mold cavity. After solidification and shaping, the product is obtained.

Working principle of zipper machine: Injection molding is a cyclic process, each cycle mainly includes: quantitative feeding - melting plasticization - pressure injection - mold filling and cooling - mold opening and pulling. After pulling out the plastic part, close the mold again and proceed to the next cycle.

Zipper machine operation items: Zipper machine operation items include three aspects: keyboard control operation, electrical control system operation, and hydraulic system operation. Select the injection process action, feeding action, injection pressure, injection speed, and ejection type separately, monitor the temperature of each section of the material cylinder, and adjust the injection pressure and back pressure.

The molding process of a general screw zipper machine is as follows: firstly, granular or powdered plastic is added into the barrel, and the plastic is melted by the rotation of the screw and the heating of the outer wall of the barrel. Then, the machine performs mold closing and the injection seat is moved forward, so that the nozzle is tightly attached to the sprue of the mold. Then, pressure oil is introduced into the injection cylinder to advance the screw forward, so that the molten material is injected into the closed mold with a low temperature at a high pressure and fast speed. After a certain period of time and pressure maintenance (also known as pressure holding) and cooling, it solidifies and forms. The mold can be opened to take out the product (the purpose of pressure holding is to prevent the backflow of molten material in the mold cavity, supplement the material into the mold cavity, and ensure that the product has a certain density). And dimensional tolerances) The basic requirements for injection molding of zipper machines are plasticization, injection, and molding. Plasticization is a prerequisite for achieving and ensuring the quality of molded products, and in order to meet the requirements of molding, injection must ensure sufficient pressure and speed. At the same time, due to the high injection pressure, a corresponding high pressure is generated in the mold cavity (the average pressure inside the mold cavity is generally between 20-45 MPa), so there must be sufficient clamping force. It can be seen that the injection device and the mold clamping device are key components of the injection molding machine.

There are three main aspects to evaluating plastic products. The first is appearance quality, including integrity, color, gloss, etc; The second is the accuracy between size and relative position; The third is the physical, chemical, and electrical properties corresponding to the intended use. These quality requirements also vary in scale depending on the usage scenario of the product. The main defects of the product lie in the design of the mold, manufacturing accuracy, and degree of wear and tear. But in fact, technicians in plastic processing plants often struggle to overcome the difficulty of using technological means to compensate for mold defects without achieving significant results.

The adjustment of processes during the production process is a necessary way to improve the quality and output of products. Due to the short injection molding cycle itself, if the process conditions are not well controlled, waste products will continue to flow endlessly. When adjusting the process, it is best to only change one condition at a time and observe several times. If the pressure, temperature, and time are all adjusted together, it is easy to cause confusion and misunderstanding, and if there is a problem, it is not clear what the reason is. There are various measures and means to adjust the process. For example, there are more than ten possible ways to solve the problem of insufficient product annotation. To truly solve the problem, one or two main solutions must be chosen to address the crux of the problem. In addition, attention should be paid to the dialectical relationship in the solution. The working principle of the zipper machine is as follows: when the product has dents, sometimes the material temperature needs to be increased, and sometimes the material temperature needs to be lowered; Sometimes we need to increase the amount of material, and sometimes we need to reduce the amount of material. To acknowledge the feasibility of reverse measures in solving problems.