Plastic Extrusion Process

The plastic extrusion process and fabricator starts by placing raw resin into the extruder’s hopper. Essential additives for the particular application (such as UV inhibitors, anti-oxidants, or colorants) are then added to the plastic extrusion equipment. Once in cast, the resin is usually gravity-fed through the feed throat of the hopper down into the extruder’s barrel. Within the barrel is a long, rotating screw that exerts the resin forward in the barrel to the die which helps the extrusion process move along.

As the resin moves along within the barrel, it is exposed to enormously high temperatures until it propels to melt. Depending on the type of thermoplastic, barrel temperatures can range between 400 and 530 degrees Fahrenheit. Once the molten plastic progresses to the end of the barrel, it is forced through a screen pack and fed into the feed pipe that leads to the die.

During the extrusion process, the screen, covered by a breaker plate due, serves to get rid of contaminants that may be present in the molten plastic. The corrosity of the screen and other factors can be manipulated until uniform melting occurs as a result of the real amount of back pressure.

Once in the feed pipe, the material is fed into the die cavity, where it cools and solidifies. To accelerate the cooling process, the newly formed plastic gets a sealed water bath. In the case of plastic extrusions, cooling rolls replace the water bath.