Views: 17 Author: Site Editor Publish Time: 2022-04-27 Origin: Site
With more and more research, the underwater pelletizer now has more and more advantageous features, especially dust purification plays a big role in environmental protection work. In this article, we will talk about how the underwater pelletizer purifies dust and how to clean the underwater pelletizer.
Here is the list of contents
How does the underwater pelletizer purify dust?
How to clean the underwater pelletizer?
Underwater granulator is mainly used for extrusion of biodegradable masterbatch, condensation of polyamide, polyurethane polymerization reaction; carbon powder, magnetic powder granulation, cable insulation materials, sheath materials, low smoke halogen-free flame retardant PVC cable materials, and various silane cross-linked materials preparation; filling, blending, modification, addition, chlorination, processing of polypropylene and rubber, plastic and engineering resin of high water absorption resin.
In the case that the underwater granulator is not yet used, most of the raw materials used in the industry are mostly in powder form, so there will be a small amount of loss during the transportation process, resulting in dust pollution. Therefore, in response to this phenomenon, the underwater granulator was developed to reverse the powdered particles into granular form.
In the field of chemical, petrochemical, pharmaceutical, food, building materials, mining and metallurgy, environmental protection, printing and dyeing, ceramics, rubber, plastics, etc., the demand for raw materials is the most, and the underwater granulator makes materials into specific shapes to assist companies in transportation. It is more convenient to carry, reduces the loss of production cost, and increases the environmental purification; it has made a lot of contribution to our environmental protection.
The cleaning method of underwater pelletizer barrel is usually oil cleaning, but compared to oil cleaning, material change cleaning can save more raw materials. There are two main methods of material exchange cleaning, as follows.
Direct material change method. If the raw material to be replaced and the melting temperature of the remaining material in the barrel is the same, you can use the direct replacement method. The operation procedure of direct material change is as follows. If the forming temperature of the raw material to be replaced is higher than the temperature of the remaining material in the barrel, the temperature of the barrel and nozzle should be raised to the minimum processing temperature of the raw material to be replaced, and then the replacement should be performed. Add the material to be replaced and open the head for direct extrusion. Until the remaining material in the barrel is cleaned out, then adjust the temperature for normal production. If the forming temperature of the material to be replaced is lower than the temperature of the remaining material in the barrel, the barrel temperature should be increased so that the remaining material is in optimal flow, then the healing power of the barrel should be increased and the nozzle should be cut off. The material is washed under undercooling, and when the temperature drops to the processing temperature to be changed, it can be transferred to production.
Indirect material change method. If the material is to be changed and the remaining material in the barrel does not have a common melting temperature, the indirect refueling method can be used. The procedure for indirect refueling is as follows. If the molding temperature of the material to be replaced is high, and the remaining material in the barrel is sensitive to heat, such as polyvinyl chloride, polyformaldehyde, etc., in order to prevent plastic decomposition, the two-step cleaning method should be used, that is, thermal stability should be used first. Use plastics such as polystyrene or low-density polyethylene or recycled plastic of this plastic as transitional cleaning material for transitional cleaning, and then replace the transitional cleaning material with the material to be replaced. Remove the screws. Since the screw of a twin-screw plastic pelletizer is relatively easy to remove, the oiling method described above is not required in many cases. This method saves raw materials.
