Waste Plastic Dry-cleaning Machine Description:
At present, the traditional cleaning technology of waste plastics is mostly used in plastic recycling industry. The cleaning medium is water or water and detergent. According to the variety of waste plastic film pollution, the specific cleaning methods are different. The cleaning of agricultural film and packaging materials includes removal of oil cleaning, high speed friction, cold washing, drying and other processes. The cleaning of containers for toxic drugs includes neutralization, disinfection, solution cleaning, high speed friction, cold washing, drying and so on.
Water cleaning technology is a more mature technology widely used in China at present. The purity of the recycled particles is high, which can be used as the raw material of high quality plastic products. But the high running cost caused by repeated crushing and cleaning is the main shortcoming of the technology. Moreover, the large amount of waste water produced during the cleaning process causes two pollution to the environment and the cost of subsequent treatment is also very high.
Film Dry Washing technology has become a research direction of waste plastics recycling industry. Film Dry Washing technology does not use water as a medium, generally use air as a cleaning medium, so no waste water is produced, two pollution is greatly reduced, and water resources are saved at the same time. In the Film Dry Washing technology, the impurities in waste films can be removed and the purity of the regenerated particles can be improved by combining the cleaning and separation of impurities.
Main advantages compared with traditional washing:
The waste plastic dry-cleaning machine has improved the quality of products and the output of materials. As the recovered material is dry, the energy required for extrusion is reduced. The cost per ton of dry washing is 30% lower than the cost of conventional washing.
Equipment maintenance also saves cost. Because the impurity separation is very clean, the damaged parts such as screw, barrel and filter of the subsequent pelletizer/granulator can be effectively protected. No bubbles were generated during the processing, and the replacement time of the screen filter was prolonged. For screw and barrel, their service life is also extended to two times than original ones.
Technical parameters of Waste Plastic Dry-cleaning Machine
1.Motor power: 55kw
2.Driving way: wheel drive
6.Outlet size: 267×247mm
7.Drum diameter: ф2416mm
8.Air pump pipe
9.With discharge tank
Development of Dry Cleaning Technology for Waste Plastics
Dry cleaning of waste plastic film is a key research area at present. Some enterprises in Japan and Europe are doing research in this area. This technology can clean all waste plastics by dry cleaning.
Dry cleaning process does not use water as medium, generally uses air as cleaning medium, so there is no waste water, secondary pollution is greatly reduced, and water resources are saved. In dry granulation process, the combination of dry cleaning and separation of impurities can effectively remove the impurities in waste film, improve the purity of regenerated particles, and give full play to the advantages of dry granulation process.
As the research on dry cleaning technology of waste plastic film has just started in China, the cleaning effect of dry cleaning technology experimental device on waste plastic film needs to be further improved, but it can be used as a pretreatment process before water washing to remove most of the dirt in waste plastic film and reduce the subsequent water consumption.
The basic requirements of dry cleaning process for waste plastic film are as follows: irregular circular shape, 5 to 15 mm in diameter, less than 1.0% of residual moisture and 10 to 30 kg/cm3 in bulk density.
Mechanism of Dry Process Technology
Dry cleaning of waste plastics is to use physical forces such as friction, grinding and collision to make waste plastics fragments collide with hard objects, and between fragments and fragments collide, friction and grind. Under the action of these physical forces, the fouling adhering to the thin film is separated from the thin film and dispersed in the air medium. The fouling and thin film separated from the thin film are sent to the dust collector and cyclone separator for dust removal and separation, and finally a clean thin film is obtained.
In this process, there are two factors that play a role: cleaning medium and cleaning force. Air is used as the cleaning medium for dry cleaning of waste plastics. Compressed air is used because the cleaning force is mainly supplied by air. Cleaning force as a physical force, there are collision, friction, grinding and other forms. The main ways are the collision and friction between diaphragm and hard object, the friction and abrasion between diaphragm and diaphragm, etc.
Dry cleaning process
According to the principle of dry cleaning of waste plastics, its technological process consists of three parts: pretreatment, cleaning and separation. In the pretreatment stage, materials suitable for dry cleaning are needed; in the cleaning stage, the dirt on the fragments is removed from the fragments; and in the separation stage, the dirt falling off is separated from the fragments to obtain clean fragments.
1. Feeding; 2. Coarse Crusher; 3. Conveyor; 4. Dry Coarse Cleaner; 5. Crusher; 6. Dust Collector; 7. Cleaner; 8. Dust Collector; 9. Soil and other dirt; 10. Cyclone Separator; 11. Clean Fragments
Pretreatment of Waste Plastics before Drying Process
Because the film is easy to curl under the force, the dirt will be wrapped in it, which is not easy to remove. Therefore, it is necessary to pretreat the waste film before dry cleaning. The main pretreatment methods are crushing and drying. The purpose is to obtain a dry waste film sheet with a certain size, so as to facilitate the cleaning by dry cleaning equipment.
In the pretreatment stage, the larger sand, mud and small stone inclusions in the waste film are removed; the dirt which is not easy to remove adhered to the fragments is cleaned after entering the cleaning stage, and then through the separation stage, the cleaner fragments are obtained.
Working Principle of Dry Cleaning Machine
Dry cleaning machine is a subsystem of the cleaning stage in the dry cleaning process system of waste plastics. The core function of cleaning system of cleaning machine is to complete dry cleaning of waste plastic fragments. It consists of three parts: pneumatic conveying part, cleaning machine part and dust removal and separation part.