What are the characteristics of the exhaust plastic injection molding machine?
Exhaust plastic injection molding machine for injection molding, refers to the raw material in the process of extrusion, the volatile gas or water vapor in the raw material, can be discharged from the cylinder before the injection molding of the molten material, this kind of injection machine before the injection molding of the plastic can eliminate the gas is called exhaust injection molding machine.If these gases in the melt are not discharged, mixing in the injection molded parts will affect the strength and appearance of the products.The injection molding machine, which can discharge gas in the production process, can improve the qualified rate of injection products, reduce the drying process of this raw material before injection, and shorten the production cycle of injection products.
The equipment structure of raw materials plasticizing and injection parts in the exhaust injection molding machine is shown in figure 1.
As can be seen from FIG. 1, there are air vents on the cylinder of the plasticized injection machine of the exhaust injection molding machine. The volatile gas of the molten material can be discharged into the atmosphere directly.
FIG. 1 structure of cylinder and screw in exhaust injection molding machine
1 - the nozzle;2 - front cylinder;3 - screw;4. One host cylinder;5 -- air vent;6 - hopper
I - first stage area of screw;Ⅱ - screw exhaust area;Ⅲ - the screw of the second order area
The screw in the cylinder is separated from the exhaust area, and is divided into the first and second stages of the screw.The structure of the first stage of screw is the same as that of the gradual type screw, which is divided into feeding section, plasticizing section and measuring section.The second - order zone screw structure only has the plasticized section and the measurement section.
Exhaust injection molding of plastic raw material plasticizing, injection work order is: injection molding products with the raw material from the hopper into the barrel and screw rotation from the raw material feeding to raw material input to the plasticizing paragraphs in extrusion, high temperature and other conditions under the action of plasticized melt - flipping melting raw materials by turning the screw by the metering section to exhaust parts, decompression melting, gas evolution in row walk - melting molten material in the turn of the screw thread slot to continue forward, into the second order, further plasticizing to go to a second order district metering section, stored in the injection room - screw forward quickly, molten material is pushed into the molding mould, cooling stereotypes.