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Do You Know The ABS Plastic Injection Molding Process?

Jul. 29, 2019

Here is Vacuum Casting Mold Factory talking about the ABS plastic injecting molding process.


Plastic ABS Prototype occupies an important position in the electronics industry, machinery industry, transportation, building materials, toy manufacturing, etc. due to their large mechanical strength and good comprehensive performance, especially for slightly large cabinet structures and force components.


Plastic ABS Prototype

Plastic ABS Prototype


(1) Drying of ABS plastic

The drying conditions of ABS plastic before injection molding are as follows: dry winter season is below 75-80 °C, drying is 2~3h, summer rainy day is 80~90 °C, drying is 4~8h, if the workpiece is to achieve special excellent gloss or system The parts themselves are complex and the drying time is longer, up to 8~16h. Due to the presence of traces of water vapor, surface fogging on the surface of the part is often overlooked. It is best to convert the hopper of the machine into a hot air hopper dryer to prevent the dry ABS from re-absorbing moisture in the hopper. However, such hoppers should be enhanced in humidity monitoring to prevent overheating of the material during accidental production interruption.

(2) Injection pressure

The viscosity of the ABS melt is higher than that of polystyrene or modified polystyrene, so a higher injection pressure is used at the time of injection. Of course, not all ABS parts are subjected to high pressure, and low injection pressures can be applied to small, simple, and thick parts. During the injection process, the pressure in the cavity at the instant of gate closure often determines the surface quality of the part and the degree of silver-like defects.

The pressure is too small, the plastic shrinks greatly, the chance of disengagement from the surface of the cavity is large, and the surface of the work piece is atomized. Excessive pressure, the friction between the plastic and the cavity surface is strong, and it is easy to cause sticking.

(3) Injection speed

ABS materials have a better medium injection speed. When the injection speed is too fast, the plastic is easily burnt or the gas is separated out, so that weld defects, poor gloss, and redness of the plastic near the gate appear on the work piece. However, in the production of thin-walled and complex parts, it is necessary to ensure a high enough injection speed, otherwise it will be difficult to fill.


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