During the extrusion process, it is necessary to cool the screw to ensure smooth production and prevent the material from decomposing due to excessive plasticization temperature. For instance, cooling the feeding section of the screw prevents the excessive temperature of this section, avoiding the material from adhering to the screw's thread grooves and rotating with the screw, which affects the forward movement of the material and can lead to insufficient supply, resulting in normal production issues. The cooling of the homogenizing section of the screw is due to the high heat generated from the melting material under significant extrusion, friction, and shearing actions, leading to rapid temperature rise. Cooling is necessary to prevent material decomposition.

Injection molding screw cooling methods involve passing water or oil through the screw's central hole, which acts as a heat-conducting medium for temperature reduction. The heat-conducting medium must be maintained at a constant temperature, continuing until it reaches the screw's homogenization section. During operation, the rotating screw requires special fittings to connect to the heat-conducting medium pipeline, known as a rotating joint.