First, zipper machine working principle:
Injection molding is a cyclic process, and each cycle mainly includes: quantitative feeding - melting plasticization - pressure injection - mold filling cooling - mold opening and drawing. After pulling out the plastic part, the mold is closed again and the next cycle is carried out.
Second, zipper machine operation items:
The operation items of the zipper machine include three aspects: control keyboard operation, electrical control system operation and hydraulic system operation. The selection of injection process action, feeding action, injection pressure, injection speed, ejection type, monitoring of the temperature of each section of the cylinder, adjustment of injection pressure and back pressure, etc.
Third, the general molding process of screw zipper machine is:
First of all, granular or powdered plastic is added into the barrel, and the plastic becomes molten by rotating the screw and heating the outer wall of the barrel. Then the machine moves the mold closing and injection seat forward, so that the nozzle is tight to the gate of the mold, and then the injection cylinder is fed with pressure oil, so that the screw is pushed forward, so that the molten material is injected into the closed mold with a low temperature at a high pressure and a fast speed. After a certain amount of time and pressure holding (also known as pressure holding), cooling, so that it solidifies and forms, the mold can be opened to remove the product (the purpose of pressure holding is to prevent the reflux of the molten material in the mold cavity, to supplement the material in the mold cavity, and to ensure that the product has a certain density and dimensional tolerance). The basic requirements of injection molding are plasticizing, injection and molding. Plasticization is the prerequisite to achieve and ensure the quality of molded products, and in order to meet the requirements of molding, the injection must ensure that there is sufficient pressure and speed. At the same time, due to the high injection pressure, a correspondingly high pressure is generated in the mold cavity (the average pressure in the mold cavity is generally between 20 and 45MPa), so there must be a large enough closing force. It can be seen that the injection device and the mold device are the key components of the
injection molding machine.
There are three main aspects to the evaluation of
Plastic products, the first is the appearance of quality, including integrity, color, luster and so on; The second is the accuracy between size and relative position; The third is the corresponding physical properties, chemical properties, electrical properties and so on. These quality requirements are also different according to the use of the product, the scale of the requirements are also different. The defects of the products mainly lie in the design, manufacturing accuracy and wear degree of the mold. But in fact, the technicians of plastic processing plants often suffer from the difficult situation of using technological means to make up for the problems caused by mold defects and with little effect.
Process regulation in the production process is a necessary way to improve product quality and yield. Because the injection cycle itself is very short, if the process conditions are not good, the waste will be endless. When adjusting the process, it is best to change only one condition at a time, observe several times, if the pressure, temperature, and time are all adjusted together, it is easy to cause confusion and misunderstanding, and the problem does not know what the reason is. There are many measures and means to adjust the process. For example, there are more than ten possible solutions to solve the problem of product dissatisfaction, and one or two main solutions to solve the crux of the problem can really solve the problem. In addition, attention should be paid to the dialectical relationship in the solution. The working principle of the zipper machine, for example: the product has a depression, sometimes to increase the material temperature, sometimes to reduce the material temperature; Sometimes it is necessary to increase the amount of material, sometimes it is necessary to reduce the amount of material. It is necessary to acknowledge the feasibility of reverse measures to solve the problem
