subject: The Work of Injection Molding [print this page] In plastic industry, injection molding is widely known since it plays an important part in plastic manufacturing process. Plastic pellets are put on the large hopper and then they are sent to the heated chamber. In this chamber, the plastic will be melted. Then, the melted plastic will be injected into some different molds to be cooled so that they will harden and be shaped into the final product.
When the cool plastic is removed from the mold, the excess plastic will be scraped away and then recycled for another product. Hereafter, the finished product will be polished and cleaned.
What is the process of the injection molding?
Injection molding starts when the plastic pellets were fed into the hopper. The hopper will send them into the barrel which is heated. It has a ram injector or reciprocating screw. This screw is generally found in the machine that produces smaller parts. This screw has function to crushes the pellets so that they can be easily heated and liquefied.
After the pellets have been liquefied, the screw will force them out to the front of the barrel so that they will be injected through a nozzle into an empty mold. In the mold, the plastic is kept cool so that it will harden and can be shaped to certain product. In addition, the plates of the mold are held close by the movable platen or large plate which is attached to the hydraulic piston. It will create pressure on the mold so that it can prevent the plastic from leaking out. Leaking out is potential to cause the finished product to have deformity.
When you do injection mold, you have to stick to the rules since this process can be so complicated since there is potentially some complications arise, such as burned parts, brittle parts, surface imperfections and also deformities. You have to make sure that the mold is kept cool with even temperature since high temperature mold can cause to burnt parts. You also have to make sure that the reciprocating screw is able to move fast since jammed screw can make the liquefied resin stay in the barrel and then become arid.
