WP twin-screw extruder
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I would like to ask: when there are frequent requests to increase or decrease production, the temperature of the penultimate section of the extruder’s barrel – specifically the eighth section – fluctuates, and as a result the melt index of the particles also changes. It should be noted that the melt index remains stable before polymerization. I want to know what relationship exists between production volume and the melt index. Additionally, I’d like to learn more about the internal structure of the extruder, including the feeding section, the melting section, and the extrusion section, as well as why the temperature is lower in the second section of the barrel and higher in the other two sections
A notable feature of twin-screw extruders is that the barrel can be split, and at the same time, the screws and the liner sleeves inside the barrel can be combined in various ways.
The last edit to this post was made by yuanzhubi*n on 2016-5-27 at 16:15. The temperature of each section of the twin-screw extruder barrel changes as the load varies. The reason for the change in the melt index is that, when the load changes, the degree of mixing and shearing of the powder and additives by the twin screws also changes； So as production increases, the melt index decreases a bit. The temperature of the eighth section of the cylinder fluctuates, and it is necessary to check the heating and cooling systems of the cylinder. A common issue is internal leakage in the check valve for the return water of the temperature control system, which leads to such temperature fluctuations. If the temperature control system is working properly, there should theoretically be no significant changes in temperature. Since the second cylinder section is located near the feed section, the screw primarily functions as a conveyor in this area; there are no intense processes such as compression or shearing that generate heat. Therefore, the temperature in the second cylinder section is higher than that in the feed section, but it is not as high as the temperature in the fifth and sixth cylinder sections, where shearing occurs.
Thank you all for your answers; I’ve learned something.