In modern industrial production, plastic extruders are core equipment, widely used in the processing of pipes, profiles, films, sheets, and high-performance engineering plastics. With the advancement of materials science, an increasing number of high-melting-point engineering plastics and biodegradable plastics are entering the market, placing higher performance demands on plastic extruders.

A plastic extruder is a mechanical device that melts plastic raw material and then extrudes the molten plastic into a mold through a screw. Its basic components include a screw, barrel, heating system, variable frequency control device, and mold. By adjusting the screw speed, temperature zones, and discharge port shape, the extruder can produce plastic products of various specifications.

High-melting-point engineering plastics, such as polyamide (PA), polyetheretherketone (PEEK), and polycarbonate (PC), typically have melting points of 250°C or higher. Conventional extruders are unable to meet the processing requirements of these materials. Therefore, extruders designed specifically for high-melting-point engineering plastics typically have the following features:

• High-Temperature, Heat-Resistant Barrel and Screw

  To ensure stable operation at high temperatures, the barrel and screw are typically made of high-temperature-resistant alloys or have a hardened surface treatment. This prevents screw wear and material degradation during long-term high-temperature processing.

• Precision Heating and Temperature Control System

  High-melting-point plastics are sensitive to temperature; even the slightest deviation can cause melt decomposition or poor flow. Therefore, extruders are equipped with multi-stage precision heating zones and temperature controllers, achieving a temperature control accuracy of ±1°C to ensure consistent product quality.

• Strong Screw Design

  High-viscosity melts require greater shear and propulsion forces. Extruder screws typically feature long screws with optimized thread shapes to improve mixing uniformity and conveying efficiency.

• Efficient Cooling System

  After extrusion, the plastic needs to be cooled to set its shape. For high-melting-point materials, the cooling system uses efficient air or water cooling to ensure rapid product set and reduce residual stress.

With the growing awareness of environmental protection, many companies have begun experimenting with the production of biodegradable plastic products, such as PLA and PHA. These materials have relatively low melting points but are sensitive to heat and prone to decomposition. When designing extruders for high-melting-point plastics, it is crucial to consider the processing capabilities of biodegradable plastics:

• Multi-stage temperature control:

  Adjustable screw temperatures at different stages to meet the varying requirements of high- and low-melting-point materials.

• Quick mold change and cleaning system:

  Facilitates switching between different materials, reduces cross-contamination, and ensures environmentally friendly material performance.

• Low-shear processing options:

  Reduce the risk of biodegradable plastic degradation during extrusion and increase product yields.

Extruders suitable for high-melting-point engineering plastics are widely used not only in aerospace, automotive parts, and electronics, but also meet market demand for environmentally friendly materials. In the future, with the continued development of biodegradable materials and high-performance engineering plastics, these extruders will continue to upgrade towards intelligent, energy-efficient, and precision technologies, becoming a core piece of equipment in the plastics manufacturing industry.