Injection moulding Injection moulding is a manufacturing process

Injection moulding

• Injection moulding is a manufacturing process for producing parts by injecting molten plastic/metal into a mould • The basic manufacturing process of injection molding: plastic is melted in the plastic injection moulding machine and then injected into a mould under high pressure. There, the material is cooled and afterwards released by opening the two halves of the mold. This technique results in a plastic product with a predetermined, fixed form

Principle and working Injection molding is generally used to produce molded shapes of thermoplastic polymers. It consists of heating of thermo plastic materials until it melts and then injecting into the steel mould, where it cools and solidifies to take its final shape. The plastic materials are usually received in the granular form. It is placed in the hopper of the moulding machine from which it is fed to a heated cylinder. Granules are heated in the cylinder to melt or plasticize. The typical melting point is about 1800 C. The melting temperature varies with the material. The mould is usually made up of steel and it is water cooled. A plunger forces the molten plastics from the cylinder into the mould wherein, it cools and solidifies. The mould is opened and the molded part as well as the attached runner is removed. Figure shows the injection molding process.

BLOW MOULDING • Blow molding is the process of forming a molten tube (referred to as the parison or preform) of thermoplastic material (polymer or resin) and placing the parison or preform within a mold cavity and inflating the tube with compressed air, to take the shape of the cavity and cool the part before removing from the mold. • Any hollow thermoplastic part can be blow molded. • Parts are not just limited to bottles, where there is one opening and it is usually smaller in diameter or size than the overall body dimensions. These are some of the most common shapes used in consumer packaging, however there are other typical types of blow molded parts, including, but not limited to: • Industrial bulk containers • Lawn, garden and household items • Medical supplies and parts, toys