Underwater pelletizer template working principle and conditions


  

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The template structure of underwater pelletizer consists of four parts: mold body, polymer molding hole (die hole), heating hole and granulation belt (hard alloy composite layer).

Mold body: the body of the template, which is used to connect the extruder, the water chamber of the pelletizer, the flow channel of the polymer, the heating rod, and the hard alloy of the pelletizing belt are all embedded on it to play the role of the skeleton.

Die hole: The molten polymer is extruded from this channel.

Heating hole: Used to set up a heating rod to heat the molten polymer.

Granulation belt: the core part of the template. High-temperature molten polymer after extrusion by high-speed rotating cutter in this cut. The material requirements are high, not only high hardness, but also wear resistance, high temperature resistance and corrosion resistance.

Working principle of underwater pelletizer template

The molten polyethylene plastic is pressurized to 5.0MPa by the twin-screw extruder, filtered by the screen changer, and then divided into multiple flow channels of the template. Here, the material accelerates to the discharge end due to the gradual decrease of the diameter of the flow channel, and finally enters the pelletizing water chamber in a linear form through the die hole, where the molten polyethylene is instantly cooled by 50-70 ℃ pellet water, and it is cut into 24mm long polyethylene particles with a diameter of 2.5.3.5mm by a high-speed rotary cutter closely attached to the surface of the template, thus completing the whole granulation process, and the particles are finally transported by cooling water to a centrifugal dryer for dehydration and drying.

Template working conditions

Polymer extrusion pressure: about 4.0~5.0MPa; working temperature: 220~240 ℃; pelletizing chamber water temperature: 50~70 ℃ template is an important part of the underwater pelletizing system, with molding, heating, cutting and other three functions.

The pelletizer die plate has a number of molding holes and a nozzle of special construction, which has the function of molding viscous plastic in the molten state and minimizing pressure loss. In order to prevent the polymer from solidifying in the mold cavity, various forms of heating holes are designed in the mold plate. These heating holes are used to place heating rods to heat the molten polymer.