Injection molding is booming in the plastics industry today. It has changed the entire facet of the industry and will continue to be in the trend. But what is it?
Plastic Injection Molding is a manufacturing process which produces plastic parts by injecting materials into the mould. It is a fast among the various processes for producing plastic items in huge numbers.
What are the various steps involved in the molding process?
- Clamping
- Injection
- Dwelling
- Cooling
- Mold Opening
- Ejection
- Clamping:
An injection molding machine comprises of three basic parts namely the mold, the clamping unit and lastly the injection units. The clamping unit is that which holds the mold under pressure during the injection and cooling. It holds the two halves of the injection mold together.
- Injection:
During the injection phase, plastic materials in the form of pellets are loaded into a hopper on top of the injection unit. The pellets are then fed into the cylinder where they’re heated until they reach melted form.
Within the heating cylinder, there is a motorized screw which mixes the melted pellets and drives them up to end of the cylinder. Once the material has accumulated in front of the screw, the injection process commences.
The melted plastic is put into the mold with the help of a spruce while the pressure and speed are controlled by the screw*.
*Some injection molding machines even utilize a ram instead of a screw.
- Dwelling:
The third step of plastic injection molding i.e. the dwelling phase comprises of a pause in the injection process. The molten plastic is injected into the mold and the pressure is put on to make certain that all of the mold cavities are full.
- Cooling:
In the cooling step of plastic injection molding, the plastic is permitted to cool to its solid form inside the mold.
- Mold Opening:
The clamping unit is opened in this step. It separates the two halves of the mold.
- Ejection
An ejecting rod and plate eject the end piece from the mold. The un-used sprues and runners can be recycled for usage over again in future molds.
Some of the plastic injection molding advantages is:
- Very Efficient
- Utilization of diverse plastics
- Automation comes into existence
- It is very efficient:
When the injection mold is designed according to the customer requirements and the pressers are pre-programmed, the molding process becomes very efficient method. Many parts can also be manufactured from a single mold and reasonable in price.
- Different Plastics can be used:
While manufacturing parts, different kinds of plastics can be used at the same time and this is all possible because of the co-injection molding.
- It is an automated process:
Plastic injection molding is an automated process that is done by the help of machines and robotics. It helps in reducing the manufacturing costs and there is even a decrease in the man power.
