6.What is Blow Molding?

Blow molding technology is widely used. I hope this article can give some inspiration to friends who want to understand this knowledge.——-Vito.


Blow molding started in the glassblowing industry, where a liquid glass pulp is enclosed in a two-piece mold and then expanded by blowing into the pulp.

With the invention of polymeric thermoplastics, this technology started to rev up in the plastic bottle industry.

The outcome isn’t exactly good for the environment, but if you use biodegradable materials or recycle thermoplastic bottles made from PET, things look a bit better.

Blow Molding versus Injection Molding

So, what’s the difference between parts made by injection molding and parts made by a blow molding machine? Injection molding creates substantial parts, while blow molding creates hollow parts.

If you are looking for something that needs only one rigid wall, injection molding is the proper process. Think of bottle caps, cases, combs, and housings for computers and televisions.

If you need a flexible, structural piece that can even hold fluid, you’re best off with blow molding. No wonder, billions of water bottles stand for the blow molding technology.

How Plastic Bottles are Made

Producing plastic bottles does not greatly differ from the glassblowing process. The technology used in the bottle forming process is called Injection Blow Molding (IBM). This requires a so-called preform, which is much smaller than the actual bottle.

The preform can be transported easily; if variants do not differ in weight, it can be used uniformly. Like in the glass manufacturing process, the preform is heated up, put into the mold, and inflated.

Due to the preform, the material expands equally, resulting in better flow control, surface quality, and transparency. After the blow molding process, the bottle heads have to be threaded and the excess material cut off.

What are the Advantages of Blow Molding?

Blow molding scores especially at mass-producing at a low price. Depending on the quality of the mold, it can produce more than over 1 million pieces before it has to be replaced. The production is also very fast compared to other molding processes, ejecting a finished product every few seconds. Thin walls and water-cooled molds also reduce cycle time.

In addition, once the machine parameters are calibrated, the output quality is constant. This is achieved because factoring parameters are stable and controllable. The process of blow molding is also perfect for automation, reducing the need for workers working in a monotone environment.

If you have any specific questions about the process outlined or would like to discuss your needs in more detail,

please feel free to contact us directly via the website https://www.amanmachine.com/ or email sales3@amanmachinery.com