Seven systems for aluminum injection molds

Seven systems for aluminum injection molds

01 Dec 2019

What is injection molding, that is, the method of manufacturing plastic materials using plastic injection molding machines and molds into plastic products is called injection molding. The plastic raw material is dried and fed into the barrel, and is heated to be molten. Under the push of the screw or the piston, the nozzle and the feeding system are injected into the closed cavity, and after cooling, the mold is hardened and shaped, and the tool used in the molding process is called aluminum injection molds.

aluminum injection molds

The injection mold consists of seven systems: the guiding system, the supporting system, the forming part system, the pouring system, the cooling system, the ejection system, and the exhaust system.
The mold consisting of the above systems, the plastic through the pouring system, through the gate into the cavity, after the filling pressure is cooled by the cooling system, the product is condensed and solidified, and then ejected through the ejection system to complete a molding cycle.

Gating system
After the plastic melt exits the nozzle of the injection machine, it reaches the passage through the mold before the cavity. The molded part system is mainly designed to allow the finished product to be smoothly shot and molded to obtain an ideal product.

Cooling system
The cooling system includes a cooling water channel, a mold temperature controller, and a heating assembly.
1. The role of setting the cooling waterway
* Control mold temperature to improve the quality of plastic parts, mainly in: the effect on surface finish, residual stress, crystallinity, thermal bending.
* Shorten the molding cycle, 80% of the molding cycle is used for cooling, and a well-designed cooling system is necessary to increase productivity.
* Cool large slides to avoid jamming.
2. Cooling method
* Water cooling
* Oil cooling
* Air cooling
* Chilled water cooling

Ejection system
The ejector of the product is the last step in the injection molding process. When the product is cured in the mold, an effective way is needed to eject it from the mold. The quality of the topping will ultimately determine the quality of the product. Therefore, the ejection of the product cannot be ignored. Moreover, in the ejection, the product cannot be deformed, whitened, broken or the like to damage the product. This device is the ejection system. The ejector system has the following categories:
1. Dome needle
2. Flat thimble
3. Sleeve
4. Top block
5. Stripping plate
6. Oblique pin
7. Gas top

Exhaust system
The purpose of the exhaust is to reduce the inconvenience such as air entrainment and scorching caused by the presence of gas in the mold.
Gas source
a. The air present in the feed system and cavity
b. Evaporation of water in plastics
c. Plastic decomposition produces gas
d. Decomposition or chemical reaction of certain additives in plastics

Guidance system
In the mold, the guiding mechanism is mainly used to ensure the exact matching between the male mold and the female mold or other parts in the mold to ensure the shape and dimensional accuracy of the plastic products, and to avoid various parts in the mold. Collision and interference occur.

Support system
The injection molding machine has a large injection pressure. When the span between the two mold legs is large and the strength of the male formwork is insufficient, the male formwork will produce a twist deformation. The use of the support column (SP) is to form a number of fulcrums at the bottom of the male formwork to minimize the deformation of the male formwork.