I was at a point in my life where I wanted to see what it was like to do something I’d never done before. I wanted to see how things so simple that I see in everyday use were made, and who it was that made them! We buy our products from name brand stores, but do we ever stop to ask ourselves how the product itself came to be? Nobody really stops to think of what goes into making something as simple as a roll of tape. When I started asking these questions, I was introduced to plastic manufacturing. The name itself was fun to say, and I went to a couple of companies to do some hands-on research on the subject. To my surprise, I learned way more than I thought I would, and I was actually catching on really fast!
The plastic extrusion process is aided primarily with the help of a machine. This machine can most obviously be referred to as a plastic extruder. This machine’s primary use is to heat, purify, and shape a material called thermoplastic into the company’s final product. It’s important that the thermoplastic come in the consistency of what looks like small, round beads (commonly referred to in the industry as “resin”).
Once you’ve acquired this “resin”, you’ll need to fill up a hopper with it. A hopper is sort of like a truck, which gravity feeds the thermoplastic into a barrel attached to the extruder. Also, in order to make your injection molded parts more desirable, different colorants can be added. This is to be done before putting the thermoplastic “resin” into the hopper.
Once a specialist operates the hopper, successfully feeding the resin into the barrel, it meets what is called a “feedthroat.” All a feedthroat essentially is, is an opening at the rear bottom of the barrel. The resin travels through the feedthroat and it meets an industrial-sized screw. The screw pushes the resin at generally 120 rpm back into the barrel, which then begins to gradually heat itself.
Most of the commonly used extruders come equipped with cooling fans. What this accomplishes is to keep the temperature below a certain point (which a specialist establishes at the beginning of the process). The screw is also a truly essential bit of the process. There are five possible zones in your average thermoplastic screw, and depending on what plastic company you’re looking into, the specialists refer them to as different names!
Towards the front of the barrel, the now melted plastic is pushed down the length of the screw. It passes through several screens so as to remove any contaminants in the melt (this is very important!). These screens are held in place by what’s called a “breaker plate”, which is a flat, circular piece of the machine that has many holes drilled into it.
The next step, and arguably the most important, is what follows the filtering process. Once it is filtered and the molten thermoplastic is free to flow through the large holes in the breaker plate, it enters the die. The die is so important due to the fact that it sets the profile for the plastic product that the plastic company wants to make. It’s a really great device, and incredibly interesting to see in action!
It’s very important to note that at this step in the plastic extrusion process, one should be extra careful that the flow of molten plastic is steady. This is due to the fact that there is a risk of putting unattractive marks and stresses into the profile of your final product. Believe me, nobody wants this, because if they’re too noticeable they may have to be thrown away.
The cooling process must be handled with extreme care. Often times, plastic product manufacturer place the product in a sort of bath to cool off, yet this takes longer than one might expect. Plastic Molded Products are truly great insulators of heat and cooling them quickly is no easy job. Plastic Product Manufacturing is not at all in the slightest a simple process, and learning about the things that go into what makes the weather stripping, deck railing, and wire insulation at my home was a one of a kind experience!
- Elijah Mort







