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What is the working principle of twin-screw extruder

Update:26 Apr 2019
Summary:

Inlet area What basically happens here is the inhalatio […]

Inlet area

What basically happens here is the inhalation, compression and delivery of the raw materials. These materials may be resins or granules.

If you want to give yourself a unique product feature, you can choose to add additives at this stage.

As compression progresses, air removal occurs, leaving no air on the material.

The resin is fed through a hopper into a twin screw extruder and through the feed throat into the screw. Then the screw moves the material forward.

The suction capacity depends on a number of factors, including screw speed and resin density. It also depends on the channel depth and pitch of the screw.

Keep in mind that if friction occurs between the resin and the barrel, the material can only move forward.

·Melting zone

Once the material enters the screw, the extrusion process begins. The screw pushes the resin forward.

When this happens, friction occurs between the material and the barrel to melt the resin.

The extra heat comes from the heater below the bucket. This ensures that the resin is completely melted.

One thing to note here is that as the resin moves forward, the depth of the channel decreases, increasing the friction and pressure within the barrel.

Different types of twin screws work together in this section. You have the same direction rotating screw and the counter rotating screw.

·Measuring area

Once the polymer has melted, they exit the extruder through a crushing plate with a screen. These screens help to remove impurities from the molten polymer.

Melting of the particles which do not melt in the melt zone also occurs here. This ensures the uniformity of the molten resin.

If plastic uniformity is to be achieved, the number of screens and the porosity of the screen can be controlled.

Also here, the molten polymer is discharged in a straight line, thereby eliminating the spiral effect on the polymer.

The pressure in this portion is high so that the molten polymer can be continuously extruded and formed into a shape. In this section, air is pumped to prevent plastic products from collapsing.

·Cooling area

The plastic product moves to the cooling zone where it is cooled. You can use two types of cooling systems.

There are air and water cooling systems. Depending on the type of cooling system you use, the plastic product will cool slowly.

This allows plastic products to form the perfect shape and give it the appeal it deserves.

·The last contact

Once cooled, you can add any final touches you want, such as painting on plastic pipes. After that, you can arrange the pipes in the stacker.