Common types of rubber extruders include pin‑type rubber extruders and vented rubber extruders. So, how should a rubber extruder be operated during production?

The rubber extruder is used for extrusion molding. Before starting the equipment, it must first be heated; once the temperature reaches the desired set point, the mold temperature controller automatically stops heating. At that point, the drive system can be activated to run the machine, and the feed hopper can then be used to feed the rubber material.

The rubber is fed into the extruder barrel via the feed hopper for plasticization, after which it undergoes shearing, kneading, and venting as it is conveyed by the screw, generating forward pressure. Moreover, the continuous interaction among the rubber, the barrel, and the screw causes the temperature of the extruder barrel to rise steadily.

When the equipment temperature becomes too high, it can cause the rubber in the extruder to degrade or even scorch. Therefore, once the temperature reaches a set threshold, we must activate the mold‑temperature controller’s cooling function to bring the rubber’s temperature inside the barrel down.

The temperature is transmitted via a sensor to the smart electrical cabinet, which then sends a command to the mold temperature controller through its control program. The mold temperature controller subsequently delivers chilled water to cool the equipment.

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 distinct zones—feeding, compression, and metering—each serving a specific function.

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 in the production of composite sealing strips for architectural doors and windows, single‑extruded sealing strips, as well as various dense and foamed rubber products—such as strip‑shaped, bar‑shaped, tubular, and sheet‑like items—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 for production, with a feed system typically employing forced cold feeding. 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 designed to extrude tread compounds, inner tubes, rubber hoses, and various rubber profiles.

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.