The injection molding machine screw is a core component of the machine, primarily used for conveying, compacting, melting, and pressurizing plastic raw materials. Its structure and performance directly affect plasticizing efficiency and product quality.
The screw body consists of a feeding section, a compression section, and a homogenization section. The feeding section is responsible for preheating and conveying solid raw materials; the compression section achieves melting, mixing, and venting; and the homogenization section ensures the uniformity of melt temperature and flow stability. Based on differences in plastic properties, screws can be categorized into three types: gradient type (suitable for heat-sensitive materials such as PVC), abrupt type (suitable for polyolefins), and general-purpose type. The main difference lies in the length and shear strength design of the compression section. Key parameters include diameter, aspect ratio, and compression ratio, which must be matched to material properties to improve plasticizing effects. Materials often used are high-temperature and wear-resistant materials such as 38CrMoAla alloy and tungsten carbide nickel-based alloy. During use, a standardized preheating process and regular cleaning and maintenance are necessary to prevent screw slippage or mechanical damage.
