There are many sizes of injection molding machine, it is based on the injection cycle time and the injection volume to select machine for the mold. Injection volume could be from ounce to ponds for injection molding machine. The injection molding machine is used for produce plastic products.
Melt material and injection system have the following parts: Hopper, barrel for heating, injection plunger or screw.
Clamping system and hydraulic system:
Hydraulic driver movable platen and stationary platen, the mold will be mounted there. Injection molding machine with many kinds of design of the shape, generally, there have plunger and screw two kinds. The biggest different is that the way of material feed from the hopper to nozzle is not the same.
The rotating screw injection molding machine is the most used machine, due to it shorter injection time, lower melt temperature, mix better.
There many kinds of equipments to help test and control the clamping system, mold and injection system. The following are the points which will be test and control:
- Cylinder temperature
- melt temperature in the screw tab
- nozzle temperature
- mold wall temperature
- temperature of the cooling medium
- internal mold pressure
- pressure in clamping cylinder
- mold deformation
- mold breathing
- column elongation
- pressure in the screw tab
- screw advance speed
- screw displacement
- hydraulic pressure
- oil temperature
Injection molding machine injection system used the pressure air for injection, so the power is very large. Plastic Injection molding machine suitable for produce the volume products. Due to the injection machine could produce hundreds or thousands products per hour.
Injection molding machine plastic material choice:
Original, all thermoplastic resins can be injection molded, but some are difficult for molding, need the special equipments for injection. From material of polymer structure, it becomes evident that the resin with wide melting range mold easier than those with a sharp or narrow melting points. But there still have the following points should be taking care of: the plastic temperature, absorption of the resin, and the necessary properties required for the products. The actual resin has a sharp melting point, turning quickly to a liquid, which need exacting temperature controls. Polycarbonate requires high injection temperatures, while nylon absorbs moisture and will corrode the internal parts of the injection cylinder unless they are chrome plates. And also some products have its special requirements, some need the hardness, some need the transparent some need the thickness and so on.
From demanders’ side, we think they must need the high quality and most suitable Injection molding machine, the most suitable?
It should follow the step: suitable for the mold. Mold should be fit for the machine when install it. When injection, should injection the products perfect, then require injection molding machine with enough injection pressure, could injection enough material for products molding.
For machine itself, should with high performance and stable characteristic, then the machine could enlong it’s lifecycle.