It is done by a technique called the Blow molding technique. It is a technique in which the plastics are melted and are extruded into a hollow tube. The pressure is exerted to form them into the shape of the container using the pp bottle-making machines. It has been famous for years as it is a technique used worldwide to produce containers in the form of these plastic bottles made up of fantastic finishes at very affordable prices. This method is also famous because it provides the most efficient and the most cost-effective way of producing high volumes of containers for packaging.
Various factors describe why blow molding had been used so much. Some of these factors are:
These Blow molding machines have a faster cycle compared to other manufacturing processes.
It is a helpful process when it is about handling complex and challenging shapes, even if they are asymmetrical and irregular, it is famous to handle them well.
This production method is comparatively cheaper in the long run than the other methods of production as it works more efficiently and effectively, playing a good role in the production process.
Although the general purpose of these blow molding machines is to create hollow objects, like bottles or packaging, by applying pressure that forces the material into a mold cavity, which gives the object a hollow shape. If one plans to use the method of blow molding, one must be familiar with the types of blow molding and what they are used for. The main and common types of blow molding processes are known as:
In this process, the resin is heated and extruded to form parison, a vertical tube-like piece of plastic that allows compressed air to pass through. The two-part mold is used and closes at the parison at both ends. As soon as the mold is sealed, the blow pin is inserted into the neck of the bottle, and the air is blown into it. The pressure of the air causes the parison to take the shape of the mold. Including the threads in the neck portion of the mold. Mold is cooled, and the parison's bottom is cut, letting the mold open. The bottom of the parison is cut, and the bottle is placed over the conveyer belt. This process is used to manufacture
•large-size, High-Density Polyethylene (HDPE)
•Low-Density Polyethylene (LDPE)
•Polypropylene (PP) bottles with large necks
It is a special kind of extrusion molding in which the blow pin blows air into the parison, so the plastic takes the shape of the bottle; it also uses physical pressure to shape the neck area of the bottle. It is used in manufacturing bottles made with HDPE, LDPE, and PP resin and can quickly achieve critical neck dimensions.
In this molding process, the heated resin is injected into the mold using a screw. This injected plastic is molded into the shape of mold then the air is used to blow the shape into the mold. The mold is allowed to cool down. The bottle is placed over the conveyor belt once ejected from the mold. They are used in the production of HDPE, LDPE, and PP bottles with a small to medium blowup ratio.
In this process, the resin is heated and is injected into the machine using a long screw. This injected plastic is then molded into the shape.