What are the design points of a single screw barrel

The single screw barrel is an important component of extrusion machinery equipment, and its design directly affects the efficiency of the extrusion process and the quality of the final product.

The following are the design points of a single screw barrel:

Material selection

• Mechanical performance: The material is required to have good mechanical strength to withstand the enormous pressure during the production process.
• Corrosion resistance: The material needs to have good corrosion resistance to the processed plastic to prevent chemical reactions from affecting the quality of the plastic.
• Wear resistance: Due to the constant rotation and friction of the screw inside the barrel, it is required that the material has good wear resistance to extend its service life.

Barrel material

• Thickness: The wall thickness of the barrel should be selected according to the working pressure and temperature, and the thick walled cylinder theory is usually used for strength calculation.
• High temperature resistance: The barrel needs to be able to withstand high temperature environments and is usually made of heat-resistant alloy steel.
• Wear resistance: Considering long-term friction with the screw, the barrel material should have good wear resistance.
• Screw diameter
• Size determination: The diameter of the screw depends on the cross-sectional size of the processed product, the type of plastic being processed, and productivity.

Feeding section design

• Depth of feeding section screw groove: Calculate the depth of the feeding section screw groove based on the determined screw compression ratio to optimize the solid conveying capacity.
• Compression ratio and groove depth
• Geometric compression ratio: The compression ratio and groove depth of the screw should be determined based on empirical data or general formulas during design.

Screw head type

• Thread section shape: Typically, trapezoidal threads are used, with a slope angle of 10 ° to 15 ° and a radius of 0.07 to 0.13 millimeters.
• Number of screw heads
• Multi head threads and single head threads: Multi head threads have a greater positive thrust on materials and a stronger ability to grab materials, but excessive multi head threads may lead to a decrease in product quality. Therefore, the impact on product quality should be considered while improving work efficiency.

The design of a single screw barrel is a complex process that involves multiple aspects such as material selection, structural design, and processing technology. Designers need to comprehensively consider factors such as the production capacity, power consumption, and service life of extruders, while ensuring that the barrel can work stably in high temperature and high pressure environments to meet the requirements of different plastic processing.