The injection molding process is usually comprised of 6 steps:
- The clamping: An injection machine contains 3 parts – the injection mold, the clamp and the injection unit, among which, the clamping unit keeps the mold at a certain pressure, so as to ensure the consistency of the outputs.
A mold is usually made up of 2 parts.
- The injection unit: It refers to the part where the plastic pellets are fed into the hopper located at the top end of the injection unit. These pellets will be loaded into the main cylinder, where they are heated at a high temperature until they are melted into liquids. Then, inside the injection unit, a screw will turn and mix the already liquefied plastic. Once this liquid plastic has reached the ideal condition for the product, the injection process will start. The plastic liquid is forced through a running gate, of which the speed and pressure are controlled by a screw or sometimes a ram dependingon what kind of machine you are using.
- The dwelling: It represents a pause in the process when certain pressure is applied to guarantee that each of the mold cavities has been filled thoroughly. It is such an important step within the process that if the mold cavities are not filled properly, it will lead to scrap of the units.
- The cooling: This process step allows the mold to cool off for a required period of time. If this step is performed too hastily, the units will probably stick together or get deformed when it is taken out of the machine.
- Mold opens: The clamping unit will open to separate the mold. The molds which are often the most important individual part during the entire process are used over and over again, and the tooling of them can be very costly.
- The ejection: The finished product is ejected from the injection mold machine in the end. Generally speaking, a finished product will continue to be on a production line or be packed and delivered to a production line as a component of a larger product, e.g. the steering wheel of a car.
In daily life, the products that involve the application of injection molding are used every day by each of us. If it were not for injection molding, many cars would not be sold at such an affordable price. However, this process also has some disadvantages. The machines are very costly and therefore involves a lot of capital investment. When designing the parts, we must keep the production process in mind, because the process is not deemed economical for short-run productions.
Nevertheless, the disadvantages are outweighed by the greater benefits, which include the speed at which the parts are produced, the relatively low labor costs and minimal material waste. Even, the finished parts usually require no more finishing.
If you are interested in our service or in need of any technical support, please feel free to let us know. We would be happy to share what we know about plastic injection molding with you and provide the exact economical plastic injection molding solution you are looking for.