1. Working Principle

Extrusion molding is a manufacturing process in which a plasticizable compound is continuously forced through a die under specific conditions, thereby producing a product with a defined cross-sectional shape.

As the rubber compound advances along the screw, mechanical and thermal effects cause changes in its viscosity and plasticity, transforming it into a viscous fluid. Based on the material’s behavior during extrusion, the working section of the screw is typically divided into three main zones—feeding, compression, and metering—each serving distinct functions.

2. Cold-feed extrusion

Advantages: It saves on hot‑melt processing equipment, facilitates mechanization and automation, and, thanks to the main unit’s enhanced screw shear and plasticizing action, ensures uniform temperature and plasticity of the compound. It also improves the quality of extruded products, enhances surface finish, and produces semi‑finished extrudates with more stable and consistent dimensional tolerances. Furthermore, cold‑feed extrusion is less sensitive to pressure fluctuations and offers greater operational flexibility, while requiring lower capital and production costs.

3. Equipment Features

Suitable for extruding rubber compounds (EPDM, natural rubber, nitrile rubber, butyl rubber, and reclaimed rubber), it is used to produce composite sealing strips for architectural doors and windows, single‑extruded sealing strips, as well as a wide range of solid and foamed rubber products in various shapes—such as tapes, strips, tubes, and sheets—for applications in construction, electrical appliances, machinery, water conservancy, and other industries.

Cold-feed rubber sealing strip extruder: This is a type of equipment that uses cold rubber in the production process, with forced cold feeding as the standard feeding method. Cold-feed rubber extruders are characterized by high production efficiency and stable operation. Extruders are commonly used to manufacture products such as sealing strips and rubber hoses that can be produced via extrusion. An extruder is a rubber‑processing machine employed to extrude tread compounds, inner tubes, rubber hoses, and various rubber profiles.

4. Precautions

(1) Rubber extruders are used to produce extruded products. During operation, the extruder screw rotates at high speed, so care must be taken not to reach into the feed throat when feeding material. Additionally, do not wear gloves during feeding, and women should tie their hair back to prevent it from being caught in the machine.

(2) The guard covering the rubber extruder’s pulley must not be removed, as the pulley and belt are part of the transmission system. During operation, foreign objects entering the system can damage the equipment, and in some cases, splashing debris may also pose a safety hazard to personnel.

(3) Before starting the rubber extruder, the equipment must be preheated first; feeding may proceed only when the temperature has reached the allowable operating range.

(4) During production, verify that the temperature-control system is functioning properly and that the set temperature matches the requirements of the product being manufactured, thereby preventing unnecessary losses.

Hebei Shuangda Rubber and Plastics Machinery Co., Ltd. is a modern enterprise that integrates research and development, manufacturing, and sales of complete sets of extrusion equipment for rubber, silicone, and plastics. The company’s main products include rubber extruders, rubber hose extrusion lines, three‑layer composite sealing strip extrusion lines, silicone sealing strip production lines, plastic sealing strip production lines, plastic profile production lines, plastic pipe production lines, elastomer extruders, and other extrusion equipment, as well as production machinery for engineering seals, automotive seals, wire and cable applications, air‑conditioning hoses, braided hoses, automotive hoses, waterstop strips, and related products.