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Working principle and condition of underwater pelletizer template

Update:16 Aug 2019
Summary:

The template structure of the underwater pelletizer con […]

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

Mould: The body of the template 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 granulation belt are embedded on it to serve as a skeleton.

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

Heating hole: used to heat the rod to heat the molten polymer.

Granulation zone: the core of the template. After the high temperature molten polymer is extruded, it is pelletized by a high speed rotating cutter. The material requirements are high, both high hardness and wear resistance, high temperature resistance and corrosion resistance.

Underwater pelletizer template works

The molten polyethylene plastic is pressurized to 5.0 MPa by a twin-screw extruder, and the impurities may be filtered through the screen changer and then split into a plurality of flow passages of the template, where the material gradually becomes smaller due to the diameter of the flow path, and the flow direction is accelerated. The discharge end finally enters the pelletizing water chamber through the die hole, and the molten polyethylene is instantly cooled by the pellet water of 50-70 ° C, and is cut into 24 mm by a high-speed rotary cutter closely attached to the surface of the template. The long, 2.5.3.5 mm diameter polyethylene granules, the entire granulation process is completed, and the granules are finally transported by cooling water to a centrifugal dryer for dehydration drying.

Template working condition

Polymer extrusion pressure: about 4.O ~ 5.0MPa; working temperature: 220 ~ 240 ° C; pelletizing chamber water temperature: 50 ~ 70 ° C template is an important part of the underwater pelletizing system, with molding, heating, cutting, etc. Item function.

The granulator template has a number of shaped holes and special-structured nozzles that have the ability to shape viscous plastics in a molten state and minimize pressure loss. In order to prevent the polymer from solidifying in the cavity, various forms of heating holes are designed in the stencil for placing the heating rod to heat the molten polymer.