How to Engineer Plastics Using Injection Molding

Injection molding is a process where plastic is injected into a mold to create precisely engineered products. It is an extremely accurate process that can be used to manufacture miniature components to entire panels of cars. The products, no matter how intricate, are manufactured as single pieces, thus providing immense structural integrity.
Steps:
1. Design the Product
Depending on the requirements of the application, you will need to design the final product. You can work with an engineer who can help you in perfecting the product.
2. Design and Manufacture the Mold
A mold will have to be made according to the product design. If you have the capabilities, you can design and manufacture the mold. You can also commission a mold maker to design and fabricate the mold. The material of the mold should be able to withstand high temperature injection molding processes. The mold should be accurate down to 1/100th of a millimeter. CNC machining among other tooling processes is used to create the mold.
3. Purchase the Raw Materials
The correct plastic materials or resins need to be purchased to manufacture a product that is compatible with the design and application. The material needs to be carefully chosen because it will affect the performance of the application and its service life.
4. Prepare the Mold
The mold consists of two halves. Securely clamp the two parts into the machine. Hydraulic pressure moves the mold towards each other and causes them to join. Ensure that the molds are completely clean before they are used.
5. Inject the Mold
Plastic pellets are fed into a hopper, which transfers it to the machine via a tube. On the way to the outlet, the tube is heated causing the plastic to melt. Hot liquid plastic is injected into the molds.
6. Let the Plastic Set
In some time, the plastic will cool and set.
7. Remove the Part
Once the part has cooled, it shrinks. It could adhere to the mold slightly. In that case, force will have to be applied to remove the part. In some situations, force of a hand is enough to remove the part from the mold.
8. Processing of Part
The part that is ejected from the part will need to be finished. This could include trimming the edges or excess plastic from any part of the component.

Tips:
1. Choose the material according to the product and its application.
2. To efficiently eject the molded part from the system, a special liquid can be sprayed onto the mold before the material is injected.
3. Before investing time and money in the process, mold a few samples. This will help you understand whether the mold is in complete adherence to the design. Compatibility in the final application is necessary. Streamlining this process will help you in saving money and time during the production process.

Warnings:
1. Utilizing the correct technique is essential when working with injection molding machinery. Since you will be handling hot materials and high pressure machines, it’s important that you undergo the prerequisite training.
2. Ensure that you are appropriately dressed to be working with high temperature plastics. Use industry standard gloves, goggles, shoes, and other industry-regulated safety instruments and clothing.