Dongguan LIXING PLASTIC & Metal Products Co. , Ltd.

The working principle of injection molding machine is similar to the syringe used for injection

it is with the help of a screw (or plunger) thrust, the plastic has been plasticized in a good molten state (that is, viscous flow) into a closed mold cavity, through the process of solidification and finalizing products.

Injection molding is a cyclic process, each cycle mainly includes: quantitative feeding - melt plasticizing - pressure injection - mold filling - cooling - mold taking.After taking out the plastic parts and then close the mold, the next cycle.

Injection molding machine operating items: injection molding machine project including control keyboard operation, electrical control system and hydraulic system three aspects e5a48de588b6e799bee5baa631333365646332 operation.The selection of injection process movement, feeding movement, injection pressure, injection speed, ejection type, temperature monitoring of each section of the cylinder, injection pressure and back pressure adjustment, etc.

The forming process of general screw injection molding machine is as follows:First adding granular or powdered plastic barrel, and with the rotation of the screw and barrel outer wall heating make plastic molten state, then the machine forward, clamping and injection nozzle with mold gate way, then access to the injection cylinder pressure oil, make the screw to move forward, thus at high pressure and fast speed will be within the closed mold injection melting temperature is low, after a certain time and pressure maintenance (also known as the holding), cooling, make its curing, can open mold to take out the products (the holding of the purpose is to prevent cavity in the reverse flow of the molten material, supplementary material within the 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.Plasticizing is the premise to realize and guarantee the quality of molding products, and in order to meet the requirements of molding, injection must ensure enough pressure and speed.At the same time, due to the high injection pressure, the corresponding high pressure is generated in the mold cavity (the average pressure in the mold cavity is generally between 20 and 45MPa), so it is necessary to have a large enough clamping force.It can be seen that the injection device and joint die device is the key part of the injection molding machine.

The evaluation of plastic products mainly has three aspects, the first is the appearance quality, including integrity, color, luster, etc.;The second is the accuracy between size and relative position;The third is corresponding to the use of physical properties, chemical properties, electrical properties.These quality requirements according to the use of products in different occasions, the requirements of the scale is also different.The defects of the products mainly lie in the mold design, manufacturing precision and wear degree.But in fact, the technical personnel of the plastic processing factory often suffer from the difficult situation that using the technological means to make up the problem which the mold flaw brings but the result is not much.

In the process of production process regulation is a necessary way to improve the quality and output of products.As 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 and observe several times. If the pressure, temperature and time are all adjusted together, it is easy to cause confusion and misunderstanding.The measure that adjusts craft, means is many-sided.For example, there are more than ten possible solutions to the problem of product dissatisfaction. Only by choosing one or two major solutions to the problem can the problem be solved.In addition, attention should be paid to the dialectical relationship in the solution.For example: products appear sag, sometimes to raise the temperature of the material, sometimes to reduce the temperature of the material;Sometimes you have to increase the amount of material, sometimes you have to decrease the amount of material.Acknowledge the feasibility of adverse measures to solve the problem.

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