What Are the Characteristics of Using a Dual-screw Extruder? What Will Cause Mechanical Failure?

As a very important machine in the extrusion industry and plastic production industry, the dual-screw extruder is now more and more widely used. If we want to operate this machine, we should first understand What are its characteristics in the process of use? In fact, the characteristics are mainly reflected in several aspects such as sufficient melting, high production volume and energy saving.


If the double screw extruder fails, what are the possible reasons? Let's find out in the article!


Ⅰ. Characteristics of dual-screw extruder when used


1. Sufficient melting


Disperse the two screws arranged uniformly and horizontally, which increases the rolling range, improves the effect of rolling, and has a good actual effect of plasticizing. Because of the existence of two meshing areas, the rolling range is doubled and the dispersion is more well-proportioned.


2. High production volume


Taking the production of talc powder high-filling masterbatch as an example, without high stirring, the twin screw extruder machine can produce a filling masterbatch with a high concentration of 80% at one time. 52 can only produce filler masterbatch with 40% concentration, 60 kg / h without relying on high mixing or repeated processing.


3. Energy saving


Take the dual-screw extruder as an example, the main motor of 75kw, 500 rpm, produces 50% concentration of carbon black masterbatch, 180kg/hr, the main motor current is 90 amperes, and the specific power is only 0.2-0.25kw.


Ⅱ. The reasons for the failure of the dual-screw extruder


1. If the gap between the barrel and screw of the dual-screw extruder is too large, and the flow rate of the extruded melt is unstable, transverse wrinkles are prone to appear on the surface of the product.


2. The gap is too large, and the pressure of the extruded melt is unstable, so that the geometrical size error of the product section changes greatly.


3. If the gap is too large, the reflux phenomenon will increase when the molten material moves forward in the barrel, so that the molten material stays in the barrel for too long and turns yellow, which will cause discoloration or focal spots on the surface of the product.


4. The gap between the barrel and screw of the dual-screw extruder is too large, which makes the output of extruded products unstable or decreased.


5. The heating temperature control is unstable, which makes the plasticization quality of the raw materials in the barrel uneven, resulting in rough surface of the product and frequent water marks.


6. The cross-sectional size of the product is unstable, and the geometrical size error fluctuates relatively large.


After our detailed introduction, everyone must have a comprehensive understanding of the knowledge of dual-screw extruder, right? I hope you will learn more about this knowledge in the process of operating this machine!

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