It’s always important to know the ins and outs of every difficult process right? To me mostly yes, but the other day my friend was talking about what he learned about in his college class, something by the name of Plastic Extrusion. Interested to learn more on a college worthy topic I listened to his brief description. I was fascinated by how many simple things can be made out of plastic, things I never took a second to think was plastic! I learned that Plastic extrusion is a manufacturing process when plastic is put into a large heater, melted, shaped, and cut to length. As I was eager to learn a little more I did some research and asked a couple people their knowledge on plastic extrusion. The results were a lot of people had mixed reactions on knowing what it was or not!
But now after lengthy research I can call myself a plastic extrusion information center. The production of plastic being heated, melted, shaped, and cut is used for the production of plastic sheeting, wire insulation, adhesive tape. A lot of window frames are even made from plastic extrusion.
In the extrusion process small bead forms of plastic are fed into a heater extruder cavity or cylinder. In some cases ultra violet inhibitors may be added to the raw plastic beads as well. Once inside the heater the small beads enter the extruder cavity towards a screw mechanism. The screw rotates forcing the plastic material through the extruder.
This was an interesting fact; inside the heater is a whopping 400 degrees F, due to the heater having to be the same temperature of the plastic materials melting point. Over heating is a big issue in plastic extrusion and there’s one way to make it stop!
Many plastic extrusion processes involve three different heaters, set to gradually increase heat inside the cavity. That will overall make overheating not an issue. It is also very interesting how so much friction and pressure builds up inside the heater that sometimes the heater will be shut off. So, so much heat is being produces on its own.
After the high temperatures cooling fans are also employed frequently, helping to keep the plastic extrusion cavity at the desired temperature. Now it’s time for the plastic to go into a die. The die gives the plastic its profile after the die, the plastic must be cooled again.
In this Plastic Extrusion Process Plastic sheeting cannot with stand the water cooling bath that the other plastic products go through. As a result cooling rolls are used to gently cool the sheets. The lengthy amount of time and research I put into learning about plastic extrusion paid off. Now I will be the one talking about it to my friend and others will wonder what a marvel I’m talking about.
The extrusion process is used every day for household items, city structures, and simple things as tape. But no one realizes that all of this is made from extruding plastic. After everything is cooled, it is now time for the plastic to coiled or cut to length.