What Materials can be Used for Blow Molding?

Blow molding is one of the most important processes used in the manufacturing and packaging industries. Basically, it I a process that involves the formation of PET bottles of different shapes and sizes. They are made according to the different types of products, which is dependent on the specifications of any company. PET blow molding process involves the formation of molten plastic, placing the molten plastic into a mold, and introduction of air pressure into the mold to give a specific mechanical effect on the molten plastic.


Such effect allows the plastic to assume the shape of the mold. After this, the molten plastic is cooled to solidify. The monolayer or multilayer plastic formed is hollow and serves as a packaging container for different products.


Blow molding is achieved in any manufacturing industry using a particular type of machine known as the PET blowing machine or the plastic blowing machine. the machine is specifically designed for the production of a wide range of hollow plastics which are used in the packaging of products. They are indispensable tools in the hands of manufacturing industries especially those in the foods, beverages, chemical industries and a host of others.


Linear stretch blow molding


Here, we’d be discussing the blow molding process and the materials for it.


The primary material used in blow molding is the PET. There are different types of PET materials. They include;

Polyethylene terephthalate (PET): It is the most widely used material in making bottles.

High density polyethylene (HDPE).

Low density polyethylene (LDPE, LLDPE).

Polyvinyl chloride (PVC).

Polypropylene (PP)

Each of these materials varies according to their individual properties and more.

Also, the plastic blowing machine can be considered as another material in the blow molding process.


What should be considered when selecting the right materials blow molding?


The factors that affect the selection of the different usable materials or the processes of blow molding (Extrusion-blown or Injection-blown) include the following; The requirements of performance, size and shape of the piece, quality to manufacture and cost of the material. Other factors to consider when choosing the right materials for your blow molding process include the type and quality of the machine, PET bottle blowing machine price and more.


The selection of resin handling material depends on:

  • material shape, size, bulk density and flow characteristics.
  • Production requirements such as kg/hour at each location, distance from the container or storage silo to the machine, number of different materials to drive and more.
  • Methods of reception and storage of the material.

The drying of plastics depends on whether they are of the non-hygroscopic type, such as olefins or polystyrene, in which case the moisture adheres to the surface of the granules and is removed by blowing with hot air, or hygroscopic, such as polyamides, ABS and PET.


When choosing the materials to be used for blow molding, it is essential to pay attention to the factors given above. It will help you as a manufacturer in producing the best materials for your packaging needs.