Plastic injection molding helps produce consistent plastic components and products. OEMS, aftermarket suppliers, packing companies, and consumer goods manufacturers all benefit from utilizing plastic injection molding services from companies like Bridgville Plastics of Stevensville, Michigan, in the southwestern section of the state, just north of the border with Indiana.
Several Industries Use Injection Molding
Several industries use plastic injection molding, including automotive, HVAC and commercial filtration ventures. The parts made can be found in appliances, lawn and garden products, and medical centers, just to name a few.
The Process of Injection Molding
How does plastic injection molding work? An engineer comes up with an idea for a part. Then a toolmaker makes a metal mold. This is usually made from steel or aluminum. This mold may have one cavity or several cavities, and it’s designed to form a certain and precise part. Did you know with plastic injection molding the precision is amazing? It can even achieve a very tight tolerance of +/- 0.001 inches!
Polymers such as thermoplastics, thermosets and elastomers, are typically used for plastic injection molding. Pellets of the selected material get heated in a barrel of the molding machine. The mixture becomes pliant enough to be injected into the mold. Cavities get filled under pressure while two halves of a mold clamp together. The material cools and hardens into the shape of the part that was designed to be made by this mold. Then it’s time to make another part, so the process repeats after one cool part is removed, so that hot material can be put back in the mold and allowed to cool, making yet another part!
Why Plastic Injection Molding is Popular
Why is plastic injection molding popular? Well, it allows for complex metal to plastic conversions. This translates into several machining operations being turned into one single molding process, which saves time and money. Also, plastic parts are lower in weight than machined or cast metal parts.
With metal parts, you can expect corrosion down the line, but plastic parts can’t corrode. Plastic also has advantages over metal because there’s greater design freedom for things like soft edge areas and creating highly detailed parts with complex geometry.
There’s such a thing as 2 shot molding which allows for the use of both hard and soft plastic that helps create a sealing edge (also known as a soft-touch edge). The 2 shot molding process also allows for the use of two different colors. And, if you want to incorporate a non-plastic component into a design (such as a metal screw in a plastic knob), there’s “insert molding” which makes that possible.
In a world where automation is becoming the norm, plastic injection molding involves a high degree of automation which helps cut down production costs. It’s quick and efficient with little to no material waste left over. Any leftover scrap plastic, for whatever reason, can be re-ground and then reused.