What are some basic processes in blow molding?-Blow Molding Factory China | KTK

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What are some basic processes in blow molding?

Release time:

2023-02-01

Blow molding, also known as hollow blow molding, is a rapidly evolving plastic‑processing technique. Its origins date back to World War II, when it was first employed to produce low‑density polyethylene bottles. Below, we’ll outline some of the fundamental processes involved in blow molding.

Blow molding technology has found widespread application. Hollow containers can now reach volumes of several thousand liters, and some products are already manufactured under computer control. Plastics suitable for blow molding include polyethylene, polyvinyl chloride, polypropylene, and polyester, among others. Consequently, the resulting hollow containers are extensively used as industrial packaging vessels. Based on the parison‑production method, blow molding is categorized into extrusion blow molding and injection blow molding; newer developments also encompass multilayer and stretch blow molding. In addition, a tubular plastic parison—obtained by extruding or injection‑molding a thermoplastic resin—is placed, while still hot (or heated to a pliable state), into a split mold. Once the mold is closed, compressed air is immediately injected into the parison. As the parison expands, it conforms tightly to the mold’s inner surface; after cooling and demolding, various hollow articles are produced. Today, the principle underlying blow‑molding processes closely resembles that of blow molding for hollow products, except that no mold is used. From a classification standpoint, film‑blowing processes are generally regarded as a form of extrusion. As our factory’s flagship product, we are grateful for the strong support of both new and longstanding customers. While ensuring the reliability and quality of our products, we also extend favorable pricing to our valued clientele.

Simply put, blow molding involves placing pre‑processed raw material into a split mold, injecting compressed air to press the parison against the mold’s inner wall, and then demolding after cooling. Today, this process is further refined according to different techniques. For instance, an extruder softens the resin and extrudes it into a tubular parison, which is then placed in a blow‑molding mold. Compressed air is introduced to inflate the parison, followed by cooling to produce a hollow part that precisely matches the mold’s shape. It’s worth noting that in another variant, an injection‑molding machine injects a blended material into a mold to form a tubular parison. After opening the mold, the parison is transferred to a bottom mold; while still hot, the molds are closed again, and compressed air is injected to expand the parison, shaping it into a hollow product identical to the mold’s cavity. Consequently, this method is well suited for manufacturing a wide range of products, including heavy‑duty items, glassware, packaging materials, radiators, gas cylinders, industrial drums, and more, making it highly versatile. Blow‑molded parts exhibit a semi‑transparent appearance, excellent stretchability, and strong moldability, making them a reliable material choice. If you have any questions, please feel free to call us at any time. You can also find our contact information on our official website or reach out to our online customer service representatives.

The above article has introduced you to some of the basic processes involved in blow molding. If you weren’t familiar with it before, now’s the time to take a look. In the next installment, we’ll cover more related topics—stay tuned! And if you still have questions, feel free to reach out to our customer service team; they’ll be happy to help answer them.