Pay attention to the operation specifications when changing the plastic or color of the injection molding machine

First, the characteristics of various plastics and shutdown notices

Different plastic raw materials have different characteristics. When stopping the machine, the characteristics of the rubber compound should be taken into consideration, which can save time and avoid deterioration of the plastic.

ABS is a hard rubber, which has good thermal stability. It will not decompose when heated for a long time at the molding temperature. Therefore, it is only necessary to turn off the electric heat.

PS is a hard rubber, which has good thermal stability. It will not decompose when heated for a long time at the molding temperature. Therefore, it is only necessary to turn off the electric heat.

PE and PP are soft rubbers, which have good thermal stability. They will not decompose when heated for a long time at the molding temperature. Therefore, it is only necessary to turn off the electric heat.

PC temporarily pauses due to production (such as night shift does not start), the cylinder should be kept at about 160 °C, so as to avoid the moisture of the rubber. If you want to refuel, you need PE to clean the cylinder, take out the screw, and clean the screw with a copper brush.

PVC is a heat-sensitive material. Before shutting down, the electric heat is turned off, and then the PVC is pushed out until the temperature of the barrel drops to 150 ° C. Finally, the plastic in the barrel is pushed out by plastics such as PP and PE.

PMMA is easily decomposed at higher temperatures, but its thermal stability is good at normal molding temperatures, so it is only necessary to turn off the heating when shutting down.

PA plastic has good thermal stability. Do not clean the barrel before stopping, but turn off the power immediately, otherwise the plastic will deteriorate after 15 minutes.

The POM is a heat-sensitive plastic. When the machine is shut down, the pressure is lowered 10 minutes before the electric heat is turned off, and then the plastic in the barrel is continuously pushed out. When refueling, the soft rubber is first cleaned.

Second, the color change of the same material

When changing the color of the same material, try to change from a light color to a dark material, and it is easier to work from a transparent material to an opaque material. When converting from rich color to light color, when converting from opaque to transparent material, after the air is shot more than ten times, when the color is still not pure, remove the nozzle and the cylinder head to clean.

Third, the replacement of dissimilar materials

The thermoplastic adheres to the metal surface at a high temperature, and does not stick at a low temperature. The refueling action utilizes this property to adhere the material to be replaced to the inner wall of the cylinder for the high-viscosity material of the cold screw to be removed.

Fourth, the material and color are replaced at the same time

In this case, a plastic with similar characteristics should be selected and used together with a cleaning agent. The general cleaning agents are: screw cleaning agent, kerosene, and the like. If the cartridge is not cleaned in this case, remove the nozzle, clean the cylinder head, and remove the screw if necessary.