The working principle of zipper machinery

The working principle of the zipper machine is similar to that of a syringe for injection. It uses the thrust of the screw (or plunger) to inject the plasticized plastic in the molten state (that is, the viscous flow state) into the closed mold cavity. Inside, the process of obtaining the product after the curing and shaping process inside the zipper machine.

The working principle of injection molding of zipper machinery is a cycle process, each cycle mainly includes: quantitative feeding - melt plasticization - pressure injection - mold filling and cooling - mold opening and pulling. After the plastic part is pulled out, the mold is closed again for the next cycle.

The operation items of zipper machinery include control keyboard operation, electrical control system operation and hydraulic system operation. The selection of injection process action, feeding action, injection pressure, injection speed, ejection type, temperature monitoring of each section of the barrel, adjustment of injection pressure and back pressure, etc. are carried out respectively.

The molding process of the general screw zipper machine is as follows: first, the granular or powdery plastic is added to the barrel, and the plastic is melted by the rotation of the screw and the heating of the outer wall of the barrel.

Then the zipper machine closes the mold and moves the injection seat forward, so that the nozzle is close to the gate of the mold, and then pressurized oil is introduced into the injection cylinder to advance the screw, so as to High pressure and high speed inject the melt into a closed mold with a lower temperature.

After the zipper machine is kept for a certain period of time and pressure (also known as pressure holding) and cooled to solidify and form, the mold can be opened and the product can be taken out. The purpose of the zipper machine to maintain its pressure is to prevent the mold cavity The reverse flow of the melt will replenish the material into the cavity and ensure that the product has a certain density and dimensional tolerance.

The basic requirements of the working steps of zipper mechanical injection molding are plasticization, injection and molding. Plasticization is the premise of realizing and guaranteeing the quality of molded products, and in order to meet the requirements of molding, sufficient pressure and speed must be ensured during mechanical injection molding of zippers.

At the same time, due to the high injection pressure of zipper mechanical injection molding, a correspondingly high pressure is generated in the mold cavity (the average pressure in the mold cavity is generally between 20~45MPa), so there must be Sufficient clamping force. It can be seen that the injection device and the clamping device are the key components in the injection molding process of the zipper mechanical injection molding.