The Basics of Blow Molding Machines

The Basics of Blow Molding Machines

Blow molding machines are used to make plastic bottles and containers for a variety of uses. The process involves blowing molten plastic into a mold with air pressure.

The process can be done with either a reciprocating screw or an accumulator head machine. The accumulator heads collect the melted plastic until enough volume has been formed.


The extruder of a blow molding machine is responsible for melting and shaping plastic into a given shape. It is an important part of the overall manufacturing process, and it works on a simple principle. It is based on a screw, which rotates in a barrel with helical flights and heats the polymer to an extrudable state. The resulting extrudate is then shaped into a particular cross-sectional profile by pushing it through a die. The resulting product is then cooled and solidified to form the final product. Extrusion can be done with various types of materials, including metals, ceramics, modeling clay, and food products.

The main components of an extruder include the conveying system, feeding unit, screw, and barrel. The conveying system transports raw material into the hopper and conveys it through the feed zone into the barrel. It also includes a screen pack to prevent foreign material from entering the thermoplastic melt. The feed hopper is also used to prevent air entrapment, which can cause the feed screw to lose its grip and clog the die hole.

A high-quality extruder can greatly improve the production of blow molded plastic. To make sure that you get the best one, research different manufacturers and models. Compare prices and features and choose a model that fits your specific needs. You should also consider acquiring extruder operator certifications to enhance your job skills.

Clamping device

The clamping device of a blow molding machine is an important component of the overall system. It must be able to keep the mold closed against the forces developed when injection pressure pushes molten plastic into the closed mold. In addition, the clamping device must be able to blow molding machine accommodate different mold sizes and ensure that the molds are securely locked together.

To achieve this, a pair of clamp (opening and closing) movement actuators are used to join or separate the opposing mold parts. These are usually hydraulic cylinders with piston (output) rods 30 a housed in bushings which also serve as guide posts. When opening, each piston rod 30 a extends vertically downward into the hydraulic cylinder and when closing, it extends upward out of the cylinder.

During the transition from the opened to the closed position, each of these actuators moves the upper yoke assembly 12 and attached upper mold part 16 downward towards lower mold part 18. As the opposing faces of the two mold parts come into contact with each other, locking columns 20 protrude below facing surface 16 a and are axially aligned with opposing locking collars 24. In the closed position, the end of each locking column, in this case cam 20 b, protrudes into the recess in the upper end of collar 24, as shown in FIG. 9.

After the opposing mold parts make contact, a hydraulic fluid is supplied to the lower piston chamber 48 via conduit 49 to raise collar 24. This in turn engages the cams in the locking columns, which locks them in the collars and applies a clamping force to the opposed mold parts.


Blow molding is a process used to make hollow plastic products such as bottles and containers. The process is based on ancient glass blowing techniques and uses air pressure to create the product. It was first developed in the 1930s and became a popular method for making plastic containers. It was a breakthrough in manufacturing, allowing manufacturers to produce large numbers of products inexpensively. Originally, blow molding was used only for glass and cellulose acetate bottles, but since then, other types of thermoplastics have been added to the list of materials that can be blown molded.

In the blow molding process, a tube of plastic is extruded into an open mold and then inflated with air under high-pressure. The inflated plastic then hardens and becomes a hollow, lightweight part. The molded product can be easily produced and is very durable. The molding process is very versatile and can produce a wide variety of products.

The cooling system in a blow mold is important because it can affect the quality of blow molding machine factory the finished product. The design of the mold’s cooling system should consider factors such as the cooling location, the mold cavity and the product shape, and the cooling time and temperature. The most common cooling methods include box cooling channels, drilled cooling channels, and casting buried cooling channels.

Cooling system

Blow molding machines play an important role in the manufacturing of a variety of products, including glass and plastic bottles. These machines are designed to automate and streamline the three main steps of the blow molding process, which include parison extrusion, molding, and product ejection. However, not everyone is familiar with the complex technology behind these machines. This article aims to shed some light on the basics of blow molding, including its various types and applications.

The plastic in a blow molding machine is superheated and then fed through a tube called a “parison,” which looks like a large, hollow balloon with a hole in one end. It is then clamped down in a mold. Then, compressed air is blown into the parison to inflate it. The inflated parison conforms to the shape of the mold, and after it cools, it is ejected from the mold. During this cooling process, water channels within the mold assist in the cooling of the plastic.

The two most common types of blow molding are extrusion and injection. Extrusion blow molding is used for producing larger products, while injection blow molding is best suited for smaller, more complex items. Another type of blow molding is intermittent blow molding, which uses independent rates of accumulation and extrusion to reduce the suspension time and prevent sagging in the parison. This allows for larger parisons to be used and produces a stronger, more accurate product.

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