So much of daily life revolves around plastic that a good many of us take plastics for granted. Stop a minute and look around your home or office. How much plastic do you see? Probably a lot. Even things that are not primarily made from plastic contain plastic parts. And all those plastic parts have to be manufactured. So how do manufacturers do it?

 

Making plastic parts is pretty simple in principle. In practice though, it can be quite complex. There is a lot of science that goes into producing plastic parts for appliances, consumer electronics, furniture, cars, and on and on. The basic process is to design your part, choose the appropriate plastic, make a mold, fill the mold with liquid plastic, and let it cure.

 

Designing the Part

 

The first step in manufacturing a plastic part is to actually design the part. Engineers use sophisticated computer software to do the job. Once a design is complete, a prototype is generally made and tested. Any shortcomings are addressed through subsequent design modifications. This process of designing, making prototypes, and modifying continues until engineers are happy with the part.

 

Choosing the Plastic

 

Plastic is not a single type of material. While most plastics are petroleum products, manufacturers can choose bio plastics as well. Moreover, there are different types of petroleum and bio plastics offering different characteristics. By the way, that’s why you find numbers on consumer plastics. The number indicates what type of plastic you are looking at.

 

Manufacturers have one other choice to make: whether to use regrind in the manufacturing process. Regrind is recycled plastic produced by recycling companies like Tennessee-based Seraphim Plastics. Manufacturers can use a certain amount of regrind in their formulas without compromising their products. Some choose to do so, others do not.

 

Making the Mold

 

The actual manufacturing of a part requires a mold. In most cases, molds are made of stainless steel or another metal strong enough to stand up to the rigors of mass production. As for how the mold is used, that depends on the manufacturer.

 

The cheapest way to mass produce plastic parts is through a process known as injection molding. The mold is installed in a machine and connected to tubes through which liquid plastic flows. The plastic is injected into the mold under pressure, where it cools almost instantly. The finished parts are released from the mold and the process repeats.

 

There are times when injection molding is not appropriate. For example, let us go back to the prototype process. Injection mold machines require a lot of time and effort to set up. So when companies are making their prototypes, they generally utilize temporary molds that are filled manually.

 

The same is true for customized parts being manufactured for short runs. A company may not want to produce enough custom parts to justify setting up an injection molding line. So instead, they do things manually.

 

3D Printing Plastic Parts

 

While injection molding has long been the preferred method for mass-producing plastic parts, there is a new player in the market: 3D printing. In the early days, 3D printing was too costly and inefficient to utilize as a company’s main manufacturing process. But things are changing. 3D printers are less expensive and faster than ever before. They may someday replace injection molding altogether.

 

Turning plastic into the parts manufacturers need isn’t a complicated process. It is pretty easy to do and doesn’t cost a lot. That’s why plastic is so abundant in modern life. It is a cheap, easy to use material with tons of relevant applications.