Making Plastic Bottles With PET
Making plastic bottles with PET (Polyethylene Terephthalate) is an ever-expanding industry. When you’re in the supermarket looking for a popular soft drink or possibly a laundry detergent or jar of Windex, you may have noticed that glass jars have pretty much been replaced by plastic containers.
Plastic containers and jars are lighter than glass, and there will be no broken shards to sweep away should the container fall to the floor.
Making plastic bottles and jars today most often involves a particular material – Polyethylene Terephthalate (PET or PETE). These containers are made with the PET plastics resin and often with a large dollop of recycled PET – usually around 10%.
The PET is dropped from a mixer into a plastic molding machine that heats the material to approximately 600° F. The result is a thick and gooey glob of plastic that is funneled into a mold.
The resulting piece of molded plastic is referred to as a preform which is now ready to be further molded in another process that can eventually transforms the preform into jars or bottles or their component parts.
The pieces are automatically cooled and can be further formed and fashioned by a process known as reheat stretch blow molding (RSBM). In just a few seconds the material is heated just enough to make the plastic malleable. And then inserts a rod to stretch the plastic length-wise while, at the same time, blowing in air at extremely high pressure.
This will channel the preform into a bottle-shaped mold and cold water is circulated to cool and set the plastic bottle or jar almost instantly.
Amazingly, making plastic bottles with PET with the average reheat stretch blow molding machine can produce 10,660 bottles per hour. The final part of the process is completed when a conveyor belt transports the finished bottles to the packaging area, where each order is shipped to various plants and warehouses throughout the country.