Heat treatment and production process of precision injection molding

In the process of heat treatment, the deformation of precision injection mold often occurs. In order to prevent this kind of bad phenomenon, as long as we grasp the deformation law and analyze the causes, different methods can be used to prevent the deformation of mold, which can be reduced and controlled. In general, the following methods can be adopted to prevent the deformation of precision injection mold during heat treatment.
(1) Reasonable material selection: for precision injection mold, micro deformation mold steel with good material shall be selected; for mold steel with severe carbide segregation, fair casting shall be carried out; for large and non casting mold steel, solution double refining heat treatment can be carried out.
(2) The mold structure design should be fair, the thickness should not be too different, and the shape should be symmetrical. For large-scale and precision injection mold, the deformation law should be grasped and machining allowance should be reserved. For large-scale and precision injection mold, the combined structure can be used.
(3) The precision injection mold should be pre heat treated to eliminate the residual stress in the machining process.
(4) Reasonable selection of heating temperature and control of heating speed. For precision injection mold, slow heating, preheating and other balanced heating methods can be adopted to reduce the deformation of mold heat treatment.
(5) Under the condition of ensuring the hardness of the mold, the pre cooling and graded cooling quenching or temperature quenching process of the injection mold should be adopted as far as possible.
(6) For precision injection molds, under the premise of permission, vacuum heating quenching and deep cooling after quenching shall be used as far as possible.
(7) For some precise and complex dies, pre heat treatment, aging heat treatment, tempering and nitriding heat treatment can be used to control the accuracy of the dies.
(8) When repairing mold sand hole, air hole, wear and other defects, select repair equipment with small thermal impact such as cold welding machine to avoid deformation in the repair process.
There are many methods for heat treatment process operation, including hole plugging, hole binding, mechanical fixation, appropriate heating method, accurate selection of cooling direction and moving direction in the cooling medium, etc. reasonable tempering heat treatment process is also an effective measure to reduce the deformation of precision injection mold.
The raw materials of plastic products in the domestic market are mainly as follows (for example, some raw materials):.
PP: low transparency, low gloss, low rigidity, but it has stronger impact strength. It is commonly used in plastic buckets, plastic basins, folders, drinking pipes, etc.
PC: high transparency, high gloss, very brittle, common in water bottles, space cups, milk bottles and other plastic bottles.
Abs: resin is one of the five major synthetic resins. It has excellent impact resistance, heat resistance, low temperature resistance, chemical resistance, injection processing and electrical performance. It also has the characteristics of easy processing, stable product size, good surface gloss, etc. it is mainly used in milk bottles, space cups, automobiles, etc.
PE: the main products are mineral water bottle cap, PE fresh mold, milk bottle, etc.
PVC: mainly used for plastic bags, packing bags, drainage pipes, etc.
PS: printer shell, electrical shell, etc.
All plastic products have a variety of colors, and this color is mixed with pigments, which is also the technical core of plastic products. If the color ratio is good, the sales volume is very good, and the boss also attaches great importance to the privacy of color ratio.
In general, the raw materials of plastic products are mixed, such as ABS with good glossiness, PP with good resistance to falling, PC with high transparency. New products will appear by using the characteristic mixing proportion of each raw material, but such products are generally not used for food appliances.
Nowadays, plastic products are made by injection molding or blow molding, so every time a sample is designed, a new mold must be opened, and the mold generally varies from tens of thousands to hundreds of thousands, so in addition to the price of raw materials, the cost of mold is also very large. To make a finished product, there may be many parts, and each part needs an independent mold.

About PTJMould Industrial Company Limited

PTJmould is a China mold maker of plastic molds- injection mold, die casting moulds, plastic blow molding, rotational molding, medical plastic injection molding, two shot plastic injection molding, insert molding, overmolding, metal injection molding, micro injection molding, powder injection molding, ceramic injection molding, liquid injection molding, husky injection molding, household mold, casting mold, die mold tool, custom molds, china moulds, rapid prototyping tooling, plastic prototyping tooling, punch press tooling, die and tooling for mobile/ cell phone parts, automotive parts, vacuum cleaners, rechargeable tools, telephones, copiers, computers, multimedia speakers, and many other electronic products and household appliances. And also a plastic product manufacturer, mold manufacturer China– plastic parts, plastic water tank, plastic balls, plastic containers, plastic buckle, plastic anchor, plastic hanger, plastic spoon, plastic pipe fitting, plastic tumble, plastic tableware, plastic cups, plastic bottles, plastic tray, plastic cosmetic container, plastic case, plastic food container, plastic chairs, plastic caps, plastic cap closure, plastic tubes, plastic water pipes, plastic knobs, plastic tubing, plastic utility boxes, plastic racks and so on.