What is Blow/Blowing Mould?


Posted March 22, 2022 by mditld

The plastic is extruded in the form of a vertical, pinched-off tube, known as the parison. The parison is then placed between two halves of an aluminum mold, with the mold closed in order to contain the parison.
 
Blow/blowing mould is a process of producing hollow containers, from common products such as soda and water bottles to highly engineered ones, such as gas tanks and electrical enclosures. The method involves melting HDPE pellets to a consistency similar to modeling clay. The plastic is extruded in the form of a vertical, pinched-off tube, known as the parison. The parison is then placed between two halves of an aluminum mold, with the mold closed in order to contain the parison.

The blowing process begins with the injection of air into the parison. As the plastic is blown, it adheres to the mold walls and forms a solid shape. The part is ejected from the mould once it has cooled to the desired temperature. The blowing process can take up to three steps. After the initial phase of the moulding process, the plastic part is allowed to cool. Once it has cooled, it can be removed from the mold.

The blow/blowing moulding process involves inflating a plastic part with compressed air. The plastic is then forced out of the mold. After cooling, it is released from the mould. Among the many uses for this method, containers and packaging are the most common. There are multiple variations of the process, and each one has its own advantages and disadvantages. The following are a few things to keep in mind when choosing a blow/blowing moulding process.

The biggest difference between a blow/blowing mould and a traditional injection mould is the rate of shrinkage. The extrusion die, for example, has conical sides that are much steeper than the opening sides. As the plastic part is forced into the mould, it stretches and squeezes the mold walls. This stretches the part, and in some areas, it causes thinning, leading to weakness. This process can be particularly rapid in thin locations, and the apparent rigidity of the part decreases rapidly.

There are several types of blow moulding. The first is called extrusion and is used in the manufacture of milk bottles and shampoo bottles. Others include automotive ducting and watering cans. Injection blow moulding is the fastest growing, and it is a more versatile method. Injection has three stages: the preform, the bottle, and the injection. Injection-blowing also involves coextrusion, which improves barrier properties. The final product is hollow and lacks strength.

When the plastic part is hit by air, it sticks to the blow/blowing mold. When it is blown, it sticks to the mold wall, which causes it to stretch. As a result, it is not able to flow along the mold walls. During this process, the plastic part becomes progressively thinning, resulting in a weaker part. It can develop streaks, air leaks, and warping.

https://www.pet-mould.com/product/blow-mould/
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Issued By stehld
Country Angola
Categories Banking
Last Updated March 22, 2022