It is pretty much impossible to dispute the claim that we live in a world where just about everything is made from plastic. Simply think about your daily routine. You wake up, wash up, eat your breakfast, drive to work, go about your day, eat your lunch, and so on. However, at virtually every point in your day, there’s a chance that you take advantage of plastic products (like your toothbrush) that have been made by plastic extrusion machines.
But how does plastic extrusion work?
Plastic extrusion is a popular method of plastic fabrication used to quickly create products of just about any size or shape with raw materials. To begin, the extruder starts with what most typically call “thermoplastic resins”. Thermoplastic resins can be melted, processed, and then re-melted to be used again – which makes plastic extruding an inherently cost-effective solution, giving manufacturers the ability to reuse extra plastic.
Plastic used for extrusion can come in a number of forms. There are virgin beads that have not been processed and are generally considered more “pure”. Often, these beads are used special purposes where a specific grade of plastic must be used. Because extrusion uses thermoplastic resins, waste plastic can also be re-used for applications with less discerning quality standards.
While modern plastic extrusion machinery requires a skilled expert to operate, the general process is pretty simple in comparison. At the very center of the machine is the screw, or agitator – which is contained by a heated barrel. After the plastic pellets are delivered into the machine, the screw slowly pulls the pellets forward and into the barrel. The heat from the barrel and friction of the screw turning quickly melts the plastic as it is pushed into the die. The die, which is attached to the barrel, is the final shape that the mold will hold. After the plastic is forced into the die, it is subjected to a water filled vacuum environment aimed at cooling the extrusion and ensuring the proper shape of the final product.
Today, because of this time-honored process, you have many of the products, tools, and necessities that you rely on every day. They range in complexity from simple toothbrushes and rubber extrusions to complex plastic parts that go into everything from small electronics to automobiles and aircraft. You will also find plastic extrusions in the form of all kinds of plastic tubes found in places like the hospital, the gas station, and the fish-tank in your living room.