Precision injection molding processing is a very rigorous process, precision injection molding processing on the size requirements are very strict, so we need to master certain process requirements when precision injection molding processing, in order to more accurately complete the precision injection mold processing, the following special Ming precision editor to share with you some precision parts injection molding processing considerations.
A, precision injection molding shrinkage:
plastic varieties of thermoplastic molding process because there is also crystallization of the shape of the volume change, strong internal stress, frozen in the plastic parts of the residual stress, molecular orientation and other elements, and thus compared with thermosetting plastic is a larger shortening rate, shortening rate range, directional obvious, other shortening after molding, annealing or moisture conditioning treatment, the shortening rate is usually larger than the thermosetting plastic.
Second, precision injection molding process fluidity:
the fluidity of various plastics also changes due to various molding factors, the main factors affecting the following.
①High temperature material temperature will increase the fluidity, but different plastics also have differences.
② precision injection molding process pressure increases the molten material is subject to shear, liquidity also increases, especially PE, POM more sensitive, so it is appropriate to adjust the injection pressure to control the liquidity.
③ injection mold structure pouring system form, size, layout, cooling system design, molten material flow resistance and other factors directly affect the actual liquidity of the molten material in the cavity, where the molten material to reduce the temperature, increase the flow resistance of the liquidity will be reduced.
Precision parts injection molding processing how to improve the quality in the details?
Third, precision injection molding processing crystallinity:
thermoplastics according to its condensation with or without crystallization phenomenon can be divided into two categories of crystalline plastics and non-crystalline plastics, the so-called crystallization phenomenon is the plastic from the molten state to condensation, molecules from independent movement, completely in a state of no order, into the molecules to stop free movement, according to a slightly fixed position, and a tendency to make the molecular arrangement into a regular model of a phenomenon.
Fourth, precision injection molding processing of thermosensitive plastics and easily hydrolyzed plastics.
Heat-sensitive refers to certain plastics are more sensitive to heat, heat at high temperatures for a longer period of time or feed port cross-section is too small, the shear effect is large, the material temperature increases the tendency to discoloration, degradation, decomposition, with this characteristic of plastic is called heat-sensitive plastics.
Five, precision injection molding processing of moisture-absorbing plastics in a variety of additives.
So the plastic can be roughly divided into two kinds of moisture-absorbing, water-adhesive and non-water-absorbing, and not easy to adhere to the water, the water content in the material needs to be controlled within the allowable range, otherwise, at high temperature and pressure, the water becomes gas or hydrolysis, so that the resin blistering, liquidity decline, appearance and mechanical properties.
In the injection molding process, the quality of injection molded products is very important, whether for the manufacturer or for the user, how to improve the quality of products in the injection molding process?
Injection molding process mold temperature: each injection molded parts, there are exterior temperature limits, if beyond this limit then one or more adverse effects and results will occur.
Injection processing pressure: directly affects the appearance of the injection molded parts, including the appearance of smoothness, etc. If the pressure is composed of hydraulic oil, it will affect the speed of resin activity, but if the pressure is composed of the mold cavity, then it is related to the appearance of dents and wrinkles.
Injection processing speed: too fast or too slow is not good, will have a negative impact on the injection molded parts, so you should select the appropriate speed, sometimes also with the mold temperature, injection processing pressure for generalized thinking.
MINDWELL focus on precision injection molding, in-depth mastery of in-mold injection IML core technology. We have a class 10,000 purification workshop to meet the demand of customization such as air conditioning panels. According to the product structure, we choose the intelligent flexible assembly line, supporting dozens of auxiliary equipment such as pressing and closing machine, automatic oiling machine, welding machine and CDD.