Working principle diagram of plastic injection molding machine

2020/10/19 11:50:38

Plastic injection molding machine is also called plastic injection molding machine or plastic injection molding machine. It is the main molding equipment for making thermoplastic or thermosetting materials into various shapes of plastic products by plastic molding mold.

It is divided into vertical, horizontal and all electric. The plastic injection molding machine heats the plastic and applies high pressure to the molten plastic to make it shoot out and fill the mold cavity.

Working principle and operation of plastic injection molding machine.

Plastic injection molding machine is a kind of technological process which uses the screw (or plunger) to inject the plasticized melt state (i.e. viscous flow state) into the closed mold cavity and obtain the products after curing and shaping. Injection molding is a cycle process, each cycle mainly includes: quantitative feeding - melting and plasticizing - pressure injection - filling and cooling - starting mold to take parts. Take out the plastic parts and then close the mold for the next cycle.

  1. Locking die: when the die plate approaches the fixed die plate quickly, and no foreign matter is confirmed, the system turns to high pressure and locks the model.The launching platform moves forward to the designated position.

  2. Plastic injection: screw can be set to multi-stage speed, pressure and stroke to inject the melt at the front end of the barrel into the mold cavity.

  3. Cooling and holding pressure: according to the set pressure and time period, keep the pressure of the barrel, and at the same time, the mold cavity is cooled and formed.

  4. Cooling and pre molding: the products in the mold cavity continue to cool, and at the same time, the hydraulic motor drives the screw to rotate to push forward the plastic particles, and the screw moves backward under the control of the set back pressure. When the screw moves back to the predetermined position, the screw stops rotating, and the injection cylinder is released according to the setting, and the end is expected.

  5. Ejection table backward: after the completion of pre molding, the shooting table retreats to the designated position.

  6. Mold opening: pull the die back to its original position.

  7. Ejection: the ejector pin ejects the product.

The advantages of injection molding method are high production speed, high efficiency, automation of operation, variety of patterns, shape from simple to complex, size from large to small, and the product size is accurate, the product is easy to update, and can form complex shape parts. Injection molding is suitable for mass production and complex shape products and other molding processing fields.