The sop of plastic extruder
Extruding different kinds of products’ operations are not same,The following is a brief introduction to the common processes and methods for extrusion of various products.
1. Plastics for extrusion should be dried first, and preheating if it’s necessary.Before turning on the machine need to change the cleaned sieve plate and strainer, and install the head and die. After that , you need to heat the parts which need to heat on the extruder and open the cooling jacket at the bottom of the hopper. When the temperature already achieve the require, the connection head part, bolts shall be examined and hot tightening, so as to avoid the occurrence of leakage in operation. After done that, turn on the extruder and add the raw materials. Do not be quick and add too many materials. This time should pay attention to the ammeter and the piezometer in time.
2. Before the plastics are extruded, any personnel are not allowed to stand in front of the die. After extruding, should draw the extrudate slowly onto the cooling and traction equipment. Based on the indicating value of instrument and the quality of requirement, each part can be adjusted accordingly so that the whole extrusion operation reaches the normal state.
3. When stopping, normally should extrude all the materials in the extruder to convenient the next time operation. When the plastic with poor thermal stability, the machine must be squeezed out. If necessary, Soft PVC , PE or Polystyrene containing more packing can be used through the last extruding process to clean the cylinder and the screw. But no need to through the nose, the die and the filter. Those parts need to clean after uninstall.It is also stopped in the case of the loading of the extruder. This method is used to prevent the air from entering the cylinder, so as to avoid the plastic oxidation and the quality of the products in the production.
4. When clean the extruding equipment, should choose the tools of cooper wire brush, copper knife and compressed air pipe. It is seldom cleaned with solvents. If it’s necessary, Tetrahydronaphthalene is the best choice but the cost is too high. Clean the filter screen can use the method of fire.
5. When it is extruding, should pay attention to the safety of this projects: electricity, temperature and the removal of heavy components, etc. When uninstalling the screw is the first one and then the cylinder. And when installing should be installed first cylinder first , then the installation of the screw.