Plastic bottles have always been in demand. They have a lot of advantages, for example, they are durable, light in weight, portable and hence, there are a large number of people who prefer plastic bottles instead of the thermos flasks or the steel bottles. However, do you know how these bottles are manufactured? Well, it is a complex process, but with the help of the few machines in the factory, it tends to get simpler. This article throws a light on the complete plastic bottle manufacturing process. Have a look!
What is PET?
When you start out to understand the manufacturing of the plastic bottles, you would encounter the word PET and you need to understand what it means in order to understand the plastic bottle manufacturing process. Well, PET stands for Polyethylene Terephthalate and this is the raw material for the manufacturing of the plastic bottles. It is a polymer, thermoplastic polymer to be very precise. Depending upon what composition you have taken, it can be transparent, as you see in the soda bottles or the soft drink bottles, or an opaque one, as you see in some water bottles.
Starting the Process
In order to start the process, the PET is first made from the raw materials which are petroleum and some hydrocarbons of the same. A reaction is carried out between terephthalic acid and ethylene glycol so as to produce PET first of all. But, it is not used as it is. In fact, long molecular chains are created out of them as the first step. This step is known as polymerization. You have to keep in mind that this is the method with the help of which plastic for the bottles in created, the bottle making process would begin afterwards.
The bottle is generally created using the blow molding process. Most of the companies prefer the stretch version of this method. In this process, the PET is first heated so as to melt it and then put into the molds. This first mold makes them in the form of a thin tube and in the second mold, they are made into bottle shaped containers. The bottom of the bottle is joined simultaneously, so that it gets joined properly.
Then, the mold is cooled down immediately so as to give it the desired shape and set it down. For cooling, various methods can be used. When the bottle gets cooled and set properly, it can be separated from the mold. In some cases, plastic might have to be trimmed so as to give the desired shape to the bottles. Also, after they have been removed from the mold, there might be some excess plastic attached to them, which has to be checked manually. But, for removing this excess plastic, machines can be used. Once the excess plastic has been removed and the bottles are ready, they can be transported to the clients directly.