Design of plastic injection molding molds

At present, the most widely used in the production of plastic products are compression molding, pressure injection molding, injection molding, extrusion molding, hollow blow molding, vacuum molding, compressed air molding and other seven molding process methods. Among them, injection molding is the most important process. It enables the plastic to obtain a certain shape and size, and in the appearance and electrical properties, mechanical properties and other aspects to meet the make 3 improve the method (1) correct spraying release agent, do not wait for the plunger head retracted when the spray 9 accompany - then > 1 will lead to cause water accumulation problems it lower material a tube I temperature. To find the focus, there may be no drainage groove, after the mold is closed, the water above the mold will seep into the cavity again, and generate gas when it meets high temperature; Fourth, when the plunger head is retracted because the material tube sprinkles too much water, making the material tube temperature too low, and when the aluminum alloy liquid is injected into the material tube, it cools down too fast because of the temperature difference, affecting its fluidity.

The aluminum alloy for die-casting is not enough to remove slag and gas, which is mainly related to the material chosen, and also closely related to the aluminum liquid to remove slag and gas.

The temperature of aluminum liquid for die-casting should be strictly controlled, the temperature is too high, the material deteriorates, it will be brittle, and the more hydrogen it absorbs, the more the chemical reaction is as follows: 2A1+3H!=AlA+3H! The temperature is low, the whole die-casting will produce gas leakage, shrinkage, and poor surface forming; when the aluminum liquid entering the casting with the sudden drop in temperature, the solubility of the gas then drops, precipitating excess gas, forming in the casting Pore, usually known as "pinhole", usually, when the temperature control in 650 ~ 6702, die-casting product performance is more stable.



The main problems on the mold are:
① improper feeding scheme, poor exhaust, affecting the flow of metal liquid in the cavity, resulting in the internal structure of the product loosening;
② two clamping surface is not flat, die-casting fly material, run material;
③ poor design of the overflow slot, resulting in poor exhaust;
④ die-casting machine of the four guide pillar plane is not flat, mold fly material serious.

Spraying, mind to know the focus of product spraying in what part.

The oxides on the surface of aluminum liquid should be polished diligently, so as not to bring the oxidized aluminum slag into the die-casting products and form bad products.

Pay attention to test its surface and internal temperature to prevent the surface temperature of aluminum liquid and the internal temperature from being different.

When assembling the mold, the surface of the die-casting machine fixed template must be clean.

The thin flying edge produced by die-casting products must never be returned to the furnace.

The parameters of die casting must be managed by a person, and generally do not move often.

In terms of management, the following points should be noted: Improve the quality awareness of the whole staff.

Strengthen the vocational training and education of employees to improve the quality and working skills of all employees.

Strengthen the monitoring of all the links associated with quality, and people, things and objects that have an impact on the quality of die casting products must be carefully managed. Mainly including: the condition of the mold, the condition of the equipment, the quality of raw materials, the quality of the release agent, the effect of slag removal and gas removal, the process conditions, the dedication of operators, etc.
All die castings are managed by batch number, and problems are dealt with in time.