Injection molding is essential to the production industry. Injection molding and die casting are somewhat similar but with different raw materials.
For die casting, the raw materials used are metals; they must be melted at a very high temperature before they can be used. But injection molding focuses mainly on materials like glass, elastomers, thermoplastic and thermosetting polymers for the fabrication of thermoplastic materials.
This process is achieved by heating raw materials and feeding them into the mold cavity by applying pressure at a specific temperature while the chemical composition remains intact.
Injection Molding: Main parts of Injection Molding Machine:
The main features of the injection molding machine include the following:
- material hopper
- an injection ram/ rotating screw-type plunger,
- heating device (heater),
- movable pattern,
- and a mold inside the mold cavity.
The injection molding machine is designed to work horizontally. The injection molding machine is made of a barrel (cylindrical pipe). There’s a hopper positioned at one end of the barrel. A hydraulic ram or rotating screw operated by an electric motor used to exert force is located inside the barrel. A heating element (heater) is also connected to the barrel; basically, it’s used to melt the molding materials coming down from the hopper.
On the other side of the barrel, there’s a mold cavity. Mold is stored inside the mold cavity and is used for the manufacturing process. Mold basically consists of copper, aluminum, and tool steels.
Advantages of injection molding
The best part of injection molding is that you can go into the mass production of a product/item. There’s no additional cost attached to the mass production so long as the cost of the design and the molds have been covered. The cost of production is greatly minimized since you can now create more items in record time.
Also, with the injection mold, you can successfully produce thousands and millions of identical parts, which results in reliability and consistency in parts even though they’re made in large quantities.
Disadvantages of Injection Molding
As with everything else, the injection molding process also has its downsides.
The cost for injection molding can be quite on the high side, especially when you consider the tooling. Before using the injection molding process to produce your products, you must create a prototype. After creating a prototype, a prototype tool must be completed and tested. The process is not only time-consuming, but it also consumes funds.
When producing large parts as a single piece, injection molding is not the best production process for it. This is due to the limitation in size of the injection molding machine and the other mold tools needed for production.
Examples of these products that can’t be produced once are car components or parts. The car parts need to be manufactured separately before joining them later.
Finally, the disadvantage of the injection molding process is that large undercuts need a professional design so the products can come out in the best shape. However, this process is costly.