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Cleaning and maintenance of injection molding machine screw

Update:11 Jan 2020

Preparation of screw for injection molding machine: 1. […]

Preparation of screw for injection molding machine:

1. According to the production plan, confirm the materials and colors to be produced, check whether the barrel material on the machine is clean, and find out the residual materials and colors in the original screw (that is, the last production) to determine the materials used to clean the screws (require Use powder).

2. Clean the injection molding machine workbench. No debris should be allowed on the injection molding machine before washing the screw, so as not to get the debris into the cake.

3. Set the required screw washing temperature (except for POM, PVC, TPE, TPU outside the temperature must be 30 degrees higher than the original screw production temperature), and prepare the tools to separate the blocks, and the pockets to load the blocks .

The main steps of cleaning:

1. Check whether the temperature of the material pipe has been reached and whether the back pressure has reached the required level.

2. Shoot the remaining material of the screw empty and add the cleaning material. The storage material is injected by fast >> slow >> fast >> injection. Pay attention to distinguish the injected material carefully. When the material is found to be discolored, press the screw and then empty the injection. After three or four movements, the material is stored again by fast >> slow >> fast >> air injection. The above two action screws need to be repeated repeatedly to truly clean up. And separate the separated primary colors and mixed waste into different pockets.

3. If you want to produce transparent or crystal white products, the machine above 250T is required, first remove the nozzle, burn it with gas, and then clean it with waste oil or cleaning liquid.

Pay attention to two points during the cleaning process:

 1. Reasonably arrange the injection molding plan, arrange products of the same color or similar color raw materials on the same machine, and achieve "more mold changing and less washing machines".

 2. Carefully distinguish the raw materials ejected from the material tube. Except that the mixed material is waste, the same color and no impurities can be recycled and reused.

Special attention should be paid to:

1. It is forbidden to flush the hose with plastic materials with very low sol temperature (such as PU, TPR, TPE, TPU, etc.)

2. If you need to produce transparent products, you cannot use POM to clean them, which will cause greater loss of plastic materials.

3.The melting point temperature of the cleaning screw material should be higher than the melting point temperature of the remaining material in the tube.

4. If the raw material to be produced is the same as the raw material in the residual material pipe, use the same material for cleaning