How to Clean, Change Color and Change Material of Plastic Extruder

How to properly clean the screw

1. Use a torch to clean the screw immediately after use

The local heating of the acetylene flame will cause overheating of the screw side, which will cause the screw to bend. Most screws are made of 4140HT steel with tight tolerances, usually within 0.03mm. The straightness of the screw is mostly within 0.01mm. After the screw is baked and cooled by the acetylene flame, it is usually difficult to return to the original flatness. Correct and effective method: Use a torch to clean the screw immediately after use. At this time, the screw has heat during processing, so the heat distribution of the screw is still uniform.

2. Choose the right cleaner

Today, the commodity economy is highly developed, and there are many screw cleaners on the market, most of which are expensive and have different effects. Whether to use commercial cleaners depends on different plastic extrusion machinery manufacturers and production conditions; plastic processing enterprises can also use different resins to make screw cleaning materials according to their own production conditions, which can save a lot of expenses for the unit.

3. Choose the right cleaning method

The first step in cleaning the screw is to turn off the feed insert, which is to close the lower feeding port at the bottom of the hopper; then reduce the screw speed to 15-25r / min, and maintain this speed until the melt flow at the front of the die stops until. The temperature of all heating zones of the barrel should be set at 200 ° C. Once the barrel has reached this temperature, cleaning will begin immediately. Depending on the extrusion process (the die may need to be removed to reduce the risk of excessive pressure at the front end of the extruder), it must be done by one person when cleaning.

How to properly clean the barrel

1. When preparing to clean the barrel, the barrel temperature is also set at 200 ° C.

2. The circular steel brush is screwed to the drill rod and the electric drill is installed as a cleaning tool, and then the steel brush is covered with a copper wire mesh.

3. Before inserting the cleaning tool into the barrel, sprinkle some stearic acid into the barrel, or sprinkle stearic acid on the copper wire mesh of the cleaning tool;

4. After the copper wire mesh enters the barrel, start the electric drill to rotate it and move it back and forth artificially until such back and forth movement becomes no resistance;

5. After the copper wire mesh is removed from the barrel, use a cotton cloth to wipe back and forth in the barrel to remove any cleaning resin or stearic acid residue; after several such wipes, the cleaning of the barrel is complete.

Precautions for cleaning color change, screw and mold

1. First clean the outside and the inside of the plastic extrusion machinery equipment. Before switching between different materials and colors, be sure to clean the original raw materials without dead corners, especially in areas that are not easy to clean. Residual materials in the screw and barrel must be squeezed out first, and complicated equipment and molds must be removed and cleaned if necessary.

2. If cleaning agent is added after cleaning, if the machine is not heated up and the material to be produced is extruded, depending on the appearance of the extruded product, the color can be put into normal production.

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