For as much work that has been done in the field of the plastic extrusion process, you think it would be a more common point of topic. Already, a huge percentage of the things that we as consumers buy has gone through plastic extrusion. Since I have begun my research on this full-bodied topic, I have learned a number of interesting and exciting facts that have forced me to think about the things that have took place for me to live as comfortably as I do. From the machinery to the plastic materials used in the process, we have come such a way from where we were just a few decades ago. Thankfully, we have dedicated people who are full of ideas and the will to make them realities. It has been sincerely eye-opening to explore this industry, and I cannot wait to continue to do so. First, you should really know what plastic extrusion is and how it works.
Plastic extrusion refers to the process that thermosetting plastics and thermoplastics go through in order to become products that consumers shop for every day. These plastics are melted, shaped, and molded into one continuous profile. These are cut into desired lengths, depending on the length specified by one of the engineers in charge of working the machine. This is how literally thousands of products are made every day, even something as essential to some places as hurricane shutters!
The first thing a plastic extrusion company has to do is to buy a large amount of raw plastic. This plastic most typically comes in the shape of small beads, and it is referred to by those in the industry as resin. Before feeding the resin into the plastic extrusion machine, plastic companies mix different colorants in, in order to make the final product more attractive to customers. Sometimes UV ray blocking material is added in order to provide the right effect.
After additives have been mixed in with the resin, it is fed into the plastic extruder barrel, which marks the first job of the machine. The material falls through an opening at the bottom of the barrel, where it is met with an industrial sized screw. The first plastic extrusion machine to employ the use of screw revolutionized the process for all future participants. The screw twists and turns, forcing the material through the extruder cavity.
The cavity begins to heat up gradually, to the desired heat marked by a specialist before the process begins. Depending on the size of the machine, up to three heaters are sometimes used to gain the ultimate result. This makes it much less likely for the material to overheat, which can be a problem for manufacturers. If the material does overheat past the set temperature, cooling fans are automatically turned on and the heaters turned off to bring it back down to the desired temperature.
As you can see, heating the material has taken a lot of time to tune and refine in order to perfect. Thanks to the technology of machines today, batches of molten plastic are saved in places where decades ago the process may have had to start all over. When the heaters turn off and the coolers on, the molten plastic keeps itself at the average temperature by pure friction and pressure along! What an example of intuitive machine-making!
After the heating process, the plastic molded parts enter a series of parallel screens, held together by a puck-like piece of steel. These screens serve the purpose of filtering the plastic liquid in order to remove any contaminants or faults in it. This makes our plastic products sleeker, more durable, and all around more attractive. Once it passes through these screens, it enters the part of the machine called the die.
The die succeeds in shaping and molding the plastic to fit a hurricane shutter, or a piece of PVC piping. After the die does its job, the machine’s work is done, and specialists come in to do one of the most delicate steps in the plastic extrusion process, cooling the shaped and molten plastic. Cooling the plastic is so important mainly because if something goes wrong, the entire process has been in vain. Most manufacturers use sealed-water baths in order to cool the product evenly and with the least possible chance of disaster.