How PET Containers Are Made

With blow molding, a company forms hollow plastic parts such as containers. The injection molding machine manufacturers will use air pressure to inflate softened plastic into the cavity. This technology is similar to what the glass industry uses. A plastic molding machine can make jars and containers like PET containers for packages.

How the Process Works

Blow molding has two parts to it. During the first part, the manufacturer will make tubes of melted plastic. This will form the base of the molding process, no matter what kind of container the company is making. However, if the company is doing injection stretch blow molding or injection molding, it is a Preform.

In the next step of the process, the injection blow molding machine will form the tube to the right shape. One of these three processes will do this: extrusion blow molding, injection stretch blow molding, or injection blow molding.

Injection Blow Molding (IBM)

First, the machine will mold the polymer in a heated cavity on a pin to shape the interior of the preform. This might have a neck in the finished product. Eventually, the rest of the polymer will be the body of the container. When the mold opens, the core rod will move the part to the blowing station, where the machine places compressed air in it. Then the part will get blown and then cooled.

Extrusion Blow Molding (EBM)

The machine will blow hot air into the parison, inflating it to a hollow part, depending on the cavity’s shape. Parts made with this process include containers, plastic bottles, and jars. Once the plastic is cool, the mold will open to eject the part so a new parison can take its place.

Injection Stretch Blow Molding

This is similar to injection blow molding, and molten polymer will move to the injection cavity to create the preform. The core pin makes the diameter inside, just like with injection blow molding. Then the plastic molding machine will hold the part at the neck and infuse air in the shape. The stretch rod stretches the part with varying levels of air pressure.

Often, companies use this process to make soft drink bottles, cooking oil containers, and oral hygiene product containers.

Choose One of the Top Injection Blow Molding Machine Manufacturers

Here at Hisson, we offer several kinds of injection blow molding machines. These include inverted head, inverted head full electric, inverted head hybrid, and non-inverted head machines. If you need a plastic molding machine, we can help you choose the right kind. Contact us.