Introduction to Compression Moulding

Moulding is the process of shaping liquid or soft raw materials by using a fixed frame called a mould or a matrix. The mould is made of a metal container where liquid, plastic, metal, ceramic, or glass is poured. The goal is to create multiple uniform copies of the product as the final product.  The liquid cools down and takes the shape of the mould or the container. The product is removed by using release agents or ejection pins.

A product can be moulded in different ways. The different types of moulding methods of:

Injection Moulding

Injection moulding is a manufacturing process in which molten material is injected into a mould.  A lot of materials can be used for injecting. For example, metals, glass, elastomers, confections, thermoplastic and thermosetting polymers. The material is placed in a heated barrel, mixed using a helical screw, and injected into a mould cavity. This material is cooled and hardened to the shape of the cavity.

Blow Moulding

Stretch blow moulding is a manufacturing process in which a hollow plastic tube is stretched radially and axially to give it the shape of the final product, which usually is a hollow bottle or container of round shape or other complicated hollow shapes.

Thermoforming

Thermoforming is a manufacturing process in which a plastic sheet is heated to a flexible forming temperature, to mould in a specific shape as a usable product.

Roto-Moulding

Roto-moulding or rotational moulding is a manufacturing process in which a heated hollow mould is filled with a shot weight of the material. It is rotated around two perpendicular axes, leading the liquid material to disperse and stick to the walls of the mould.

Extrusion Moulding

Extrusion moulding is a manufacturing process is used to make fibres, curtain tracks, rods, pipes, hoses, and drinking straws. The melted granules are forced through a die to form a long tube-like shape. The shape of the die determines the shape of the tube. This extrusion is then cooled and formed into a solid shape. This tube may be printed upon, and cut into equal pieces. Optical fibre is one of the most famous extrusion moulding products.

Compression Moulding

Compression moulding is a manufacturing process in which the moulding material is preheated. The material is placed in an open heated cavity. The mould is closed with a top force or a plug member. Pressure is applied to the material in the mould, while heat and pressure are maintained until the material is converted into the final product. Plastic bottles manufacturers in India use compression to manufacture plastic bottles.

Different materials require different types of compression moulding. For example, Melamine wear is a thermosetting plastic product that requires compression moulding whereas auto parts require the application of compression moulding.

Application of Compression Moulding

The application of compression moulding is mainly used in manufacturing automobile parts like spoilers, scoops, fenders, hoops, and many such small and important parts. These delicate parts are made when the material is positioned in the mould cavity and the platen (the cylindrical roller in a typewriter in which the paper is held) is closed by the hydraulic ram.

Each process of moulding has its advantages. Let’s dive into the advantages of Compression Moulding.

Advantages of Compression Moulding

There are many advantages if one had to choose compression moulding for rubber and plastic products. Below are some of the major advantages of compression moulding.

• Due to its low setup cost, compression moulding is ideal for small and medium production units.
• Since the material is required to be put directly under the mould cavity, it is not limited to because of the weight of the material. This means that it can handle a large number of raw materials to create bigger products.
• Compression moulding does not require special and expensive complex tools. This means that capital investment and maintenance capital required is less.The compression moulding process is simpler as compared to other moulding techniques.
• The compression moulding process is simpler as compared to other moulding techniques.

Awanti Polymoulds is a manufacturer of PET blow moulds which started its journey in the industrial space in the year 1990 with injection mould manufacturing.  Since then they have only risen and have made a mark in manufacturing PET moulds in India and Asia as well. Awanti Polymoulds has captured the global beverage industry with its quality blow moulds for a variety of product applications