Resin cleaning method

This method uses resin, such as polyester resin or epoxy resin, to clean the machine. This method is generally used in the cleaning or extrusion of new equipment after a period of use. Due to the residual material on the screw or barrel becoming gelatinized, the extrusion speed of the material slows down, and the color difference of the color changing variety is large, this method can be used. After resin cleaning, the PVC resin to be produced is further cleaned by adding appropriate external lubrication and calcium powder. When the extruded material is considered clean, it can be officially put into production.

Non resin cleaning method

This method uses materials such as rice, corn, sawdust, and toilet paper that have a certain amount of friction and are easy to crush. When the extruder is heated to the normal extrusion temperature, these materials are used to remove the PVC resin adhesive adhering to the surface of the screw and screw by utilizing the friction between them and the screw and screw. Experience has shown that the outer shell of rice has high hardness and high friction, making the cleaning effect of the machine relatively ideal. After using this method to clean the machine, it is necessary to open the screw tube again to check the cleaning situation. Under normal circumstances, the PVC resin cleaning material formula needs to be used according to the above method before the formal production of the product can proceed.

Manual cleaning method for dismantling screws and screw barrels

This method involves heating the extruder to its operating temperature and manually or automatically pushing out the screw to remove easily removable materials while still hot. After cooling, immerse it in an organic solvent tank containing acetone or cyclohexanone. When the molten attachment attached to the screw swells, remove the attachment manually. The soaking time of the screw depends on the amount of attachment and the thickness of the adhesive. In order to reduce the use of solvents and facilitate container sealing, steel or stainless steel pipes slightly thicker than the screw diameter can be used as soaking tanks with one end welded and sealed. For safety reasons, the container for soaking the screw must be stored in a cool, away from sources of fire and power, with the mouth sealed to prevent solvent evaporation, and labeled with safety signs.

If a thorough cleaning is required, the screw can also be opened while it is still hot, and the adhesive attached to the inner wall of the screw can be removed manually or by solvent wiping.

In order not to damage the surface smoothness of the screw and barrel, hard objects cannot be used to strike them. Only steel saws or copper brushes that are softer than the steel used for the screw and barrel can be used to remove attachments to avoid damaging the screw and barrel. When the pvc formula in the extruder stays in the extruder for a long time, it is easy to plasticize the gel and the extruder cannot be started. The standard for resin feeding amount is to ensure that all the powder coating materials remaining inside the screw can be pushed out of the screw. In terms of the degree of removal of extruded materials, it is basically based on the standard that the color of the original PVC products produced cannot be seen or there is no paste.

When starting up the extruder for production, the pre mixed material should be used according to strict procedures to remove the remaining material from the extruder. Only after confirming that the material is completely removed can it be used as the official product.

In case of sudden power failure during normal operation of the extruder, if the materials inside the extruder barrel are not discharged from the outside in time, the PVC powder gel plastic will enter the viscous flow state, which will make it impossible to start the extruder. It is necessary to heat the materials in the extruder barrel at high temperature with electric heating or gas welding gun and other tools, which will easily damage the equipment. Therefore, after a power outage, the main switch of the extruder should be immediately turned off, and the extruder motor should be manually rotated with a hand belt or a shaking rod to discharge the internal materials of the extruder as much as possible and minimize the residue in the screw barrel.

If the main motor of some extruders is directly connected to the gearbox and there is no device for shaking the rod to rotate the motor, the cooling water of the cooling system can be increased to quickly cool down the temperature of the extruder barrel and screw, preventing material plasticization, viscosity, and aging in the extruder.