Application Scenarios for Barrels and Screws
As the core "heart" of extrusion equipment, barrels and screws are widely utilized in fields such as plastic compounding and granulation, food processing (e.g., puffed snacks, plant-based meat), pharmaceutical granulation, and rubber processing. They serve as the critical components responsible for material conveying, melting, mixing, and shaping.
Plastics and Rubber Industries: Compounding, Granulation, and Profile Extrusion
In the plastics and rubber sectors, barrel-and-screw assemblies are primarily employed for the compounding and modification of polymer materials, as well as for the extrusion of finished products.
Compounding and Modification: Co-rotating twin-screw extruders-distinguished by their superior mixing and devolatilization capabilities-are widely used to uniformly disperse various polymers, fillers (such as calcium carbonate and glass fibers), and additives, thereby producing high-performance modified plastic granules. When processing highly abrasive fillers, bimetallic barrels or special alloy liners are frequently adopted to extend equipment service life.
Profile and Pipe Production: Single-screw extruders or twin-screw extruders with specific configurations are utilized for the extrusion of pipes, films, and profiles. For instance, conical twin-screw extruders are often preferred for processing PVC due to their low shear heat generation and excellent plasticization efficiency; conversely, processing engineering plastics (such as PA or PC) typically involves the use of barrier-type screws to enhance plasticization quality.
Food Industry: From Snack Foods to Plant-Based Meat
Food processing represents a particularly distinctive application area for barrels and screws, leveraging High-Temperature Short-Time (HTST) extrusion technology to alter the structural properties of food materials.
Puffed Snack Foods: By subjecting cereal starches to a high-shear, high-temperature, and high-pressure environment, the starch undergoes instantaneous gelatinization and expansion, resulting in the production of crispy snacks such as chips and cereal rings. The self-cleaning capability inherent in twin-screw extruders effectively prevents material scorching or charring.
Plant-Based Protein Meat: Utilizing the "texturizing" function of twin-screw extruders, soy or pea proteins are rearranged into a fibrous structure under conditions of high temperature and high shear; this process simulates the texture of real meat and constitutes a core technology in the production of plant-based meat alternatives.
Instant and Functional Foods: These systems are also employed in the production of instant coffee powders, meal replacement powders, and nutritionally fortified food products. The screw's modular temperature control system protects heat-sensitive nutrients (such as probiotics and vitamins) from inactivation.
