Working principle of waste plastic recycling machine:
After fed into the hopper, the plastics fall smoothly on the screw and is bitten by the screw thread. Along with the rotation of screw, the plastic is forced and pushed to the direction of the nose, which forms a mechanical transport process. When the plastic feeding port runs to the machine head, with the depth of screw thread reducing and the existence of the resistance produced by sieve, splitter plate and the head of the machine. It will produce higher pressure in the process of recycling, which can press the plastic very dense to improve its conduction heat. In this way, it will help the plastic melt quickly. Meanwhile, the gradually increasing pressure can eliminate the original gas that always exists among plastics.
Along with the increasing pressure, on the one hand, the plastics will have a external heat; on the other hand, the plastics is in the process of compressing, cutting, stirring, and it will generate plenty of heat because of the internal friction. In addition, under the combination of external and internal force, the temperature of plastic will constantly increase and the physical state has also experienced the change from the glass state to the high elastic state to the viscous flow state. Generally speaking, the materials mainly stays the glass state in the process of feeding, and during the increasing reduction of screw thread, which is in the middle compressing section, it stays in the off-bounce state.
Equipment composition of Beston plastic waste recycling plant:
1. Extrusion system: the extrusion system includes screw, barrel, hopper, machine head and mold. Plastics can become the uniform melt liquid through the extrusion system, and then will be squeezed out the machine head by the screw under the pressure generated in the whole process
2. Driver system: the function of this system is to drive the screw and provide the necessary torque and speed in the last process. Drive system mainly includes the generator, reducer and bearing.
3. Heating and cooling device: the heating and cooling are the necessary conditions in the process of squeezing out the plastics.
Characteristics of the small scale waste plastic recycling plant:
Firstly, at present, extrusion machine usually use the electric heating, which can be divided into resistance heating and induction heating. The heating sheet will be installed in each part of machine body, machine neck and machine head. The heating device has installed the heating cylinder outside of the machine, which can heat the plastic to achieve the required temperature of operation.
Secondly, the cooling device is set up to make sure the plastic temperature can achieve the requirement of technology. Specifically speaking, it is mainly used to eliminate the extra heat generated by the shear friction of screw rotating, which can avoid the plastic pyrolysis, scorch or stereotyped difficulty because of the over high temperature. Barrel cooling is divided into water cooling and wind cooling. Generally, the small plastic recycling machine is suitable for the wind cooling, while the larger machine is suitable for water cooling and the mixed cooling of two methods; screw cooling mainly adopts the center water cooling in order to increase the deliver rate of solid material and stable the output, while it also can improve the quality of products; but the cooling device in the hopper is used to strength the conveying of solid material to prevent the plastic material from blocking the plug due to the high temperature; it also can ensure the normal operation of the transmission part.