Screw barrel operating pressure

The operating pressure of a screw barrel in extrusion refers to the amount of pressure that is applied to the material as it is pushed through the barrel by the screw. The pressure is generated by the rotation of the screw and is measured in pounds per square inch (PSI) or bars.

The operating pressure is a critical factor in extrusion as it determines the ability of the material to flow through the barrel, the quality of the final product, and the wear and tear on the equipment.

The operating pressure of a screw barrel in extrusion can vary depending on the specific application and the material being extruded.

For example, in the extrusion of polyethylene (PE) plastic, the operating pressure can range from 1500 PSI to 3000 PSI. In contrast, in the extrusion of polyvinyl chloride (PVC) plastic, the operating pressure can range from 2000 PSI to 4000 PSI.

They are often re-sleeved at the high pressure end of the extrusion barrel. Barrelize extrusion barrels are able to handle operating pressures of up to 700 bar, about 10,000 psi.

Another example is in the extrusion of aluminum, which usually the operating pressure should be around 800 PSI.

The operating pressure can be adjusted to suit the specific requirements of the material being extruded. For example, materials that are more difficult to extrude, such as those with a high viscosity or high melting point, may require a higher operating pressure than those that are easier to extrude.

It's important to note that the operating pressure should not be too high as it can cause damage to the material and the barrel. Additionally, if the operating pressure is too low, it may not be able to push the material through the barrel.

Screw barrel manufacturers typically recommend the operating pressure range for their specific screws, and the parameters should be followed accordingly to ensure optimal performance and longevity of the equipment.