1. During the extrusion process, the polypropylene material is converted from a glassy state to a molten state. In addition to balancing the heat required for plasticizing the material with the heat supplied so that the material can complete ideal plasticization, melting and pressing are also A very important control indicator. Since the material is affected by the die resistance and the compression ratio of each screw section during the extrusion process, it does not exist at normal pressure. For different die types, the compression ratio of each section of the screw is basically constant and unchangeable.
2. On the premise that the extrusion speed of the plastic hose extruder remains unchanged, if the feeding speed is increased or reduced, the material volume of the screw in the feeding section will change, and the material volume in the exhaust section will remain unchanged, so the feeding section and compression section will As the compression ratio changes, the melt pressure increases or decreases; while the feed speed remains unchanged, the extrusion speed increases or decreases, and the screw material volume in the feed section also changes. The material volume in the exhaust section remains unchanged, so the feeding section and compression section change with the compression ratio, and the melt pressure increases or decreases accordingly; the feeding speed increases or decreases simultaneously with the extrusion speed, because the screw material volume in the feeding section does not change. Change is only a change in melting pressure caused by an increase or decrease in speed.
