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What is the difference between injection mould and blow moulding mould?
- Mar 20, 2018 -

What is the difference between injection molding mould and blow molding mould?

1. Injection molding and blow molding process is not the same, blow molding is a note + blowing, injection molding is a note + pressure, blow molding must have that pull out of the pipe left the head, injection molding must have the gate section.

2. In general, injection molding is a solid core body, blow molding is empty core, blow molding surface is uneven. Blown air inlet.

3. Injection molding, that is, thermoplastic plastic injection molding, this method is to melt the plastic material, and then injected into the membrane cavity. Once the molten plastic has entered the mold, it will be cold in accordance with the mold cavity sample formed into a certain shape. The resulting shape is often the final finished product and no further processing is required until it is installed or used as a final finished product.

Many details, such as protruding parts, ribs, and threads, can be molded in one step of injection moulding.

The injection moulding machine has two basic components: an injection device for melting and putting plastic into a mold and a clamping device.

And the function of the mold device is:

*Make the mold closed under the pressure of injection;

*The product is taken out of the injection device in the plastic injection mold before the melt, and then control the pressure and speed of the melt injection mold. At present, there are two kinds of injection device design: Screw-type pre-plasticizing or two-stage device, as well as reciprocating screw. The screw-type pre-plasticizing device uses a pre-plasticizing screw (the first stage) to inject the molten plastic into the injection rod (second stage). The advantage of the screw pre-plasticizing device is the constant melt quality, high pressure and high speed, and accurate injection control (using the mechanical thrust device at both ends of the piston stroke). These advantages are required for transparent, thin-walled products and high production rates. The disadvantages include uneven residence time (resulting in material degradation), higher equipment costs and maintenance costs. 

The most commonly used reciprocating screw injection device does not require plunger to melt and inject plastic.

4. Blow molding: Also known as hollow blow molding, a rapid development of plastic processing methods. Tubular plastic billets obtained by extrusion or injection of thermoplastic resins, hot (or heating to soften the state), placed in the open mold, immediately after the closed mold in the form of compressed air, so that the plastic billet blowing and close to the mold wall, after cooling demoulding, that is, a variety of hollow products. Blow molding Film manufacturing process in principle and blow molding hollow products very similar, but it does not use molds, from the plastic processing technology classification of the angle, blow molding film molding process is usually included in extrusion. Blow molding Process In the Second World War, began to produce low-density polyethylene vials. In the late 50, with the birth of high-density polyethylene and blow molding machine development, blow molding technology has been widely used. The volume of hollow containers can reach thousands of liters, and some production has been controlled by computer. Suitable for blow plastic polyethylene, polyvinyl chloride, polypropylene, polyester and so on, the resulting empty containers are widely used as industrial packaging containers.