Production method of three-layer composite sealing strips

Three‑component sealing strips are very common in everyday life; the seals used on car doors, for example, are typically made of EPDM rubber. These automotive sealing strips are manufactured by combining two distinct forms of EPDM rubber—one solid and one cellular—into a single composite. During production, two extruders are employed to extrude each type of rubber separately. The two extruders are connected via a composite die, through which a steel strip is fed and co‑extruded with the rubber to form the desired sealing‑strip profile. After the basic structure of the rubber product is formed, it undergoes vulcanization using specialized equipment. We typically use hot‑air vulcanization chambers, with products generally requiring a 30‑meter‑long hot‑air chamber for this process. Once vulcanization is complete, the parts are quenched in water to cool them, after which the choice of equipment and production process depends on the specific characteristics of the product. Some items also require microwave vulcanization and high‑temperature setting stages during manufacturing, making our production line highly flexible and adaptable.

In rubber industry production, compound extruders are primarily used for extruding tire tread compounds, automotive sealing strips, colored tire treads, composite hose and rubber‑plastic co‑extrusion, as well as multi‑layer co‑extrusion of rubber sheets. Compound extrusion technology is a priority in the rubber industry; it enables the production of products that both conserve materials and meet diverse performance requirements by employing different formulations and grades of rubber compounds through specialized extrusion equipment.

Purpose:

Triple‑layer rubber seals are primarily composed of a composite structure that combines EPDM rubber foam with solid EPDM, incorporating metal reinforcement—such as steel wire or steel strips. They are widely used on car doors, door panels, door frames, side windows, front and rear windshields, engine hoods, and trunk lids, providing functions such as water and dust resistance, sound insulation, thermal insulation, vibration damping, and aesthetic enhancement.

Equipment Features:

High efficiency; improved product quality, reduced production costs, and an optimized working environment, among other benefits.

The rubber three‑component extrusion production line primarily manufactures: steel‑core rubber sealing strips, steel‑belt rubber profiled strips, steel‑belt reinforced rubber strips, automotive steel‑belt composite sealing strips, and foam‑plus‑solid‑plus‑steel‑belt rubber sealing strips.

The production of three‑layer composite sealing strips requires a wide variety of equipment and a substantial number of machines, making it a relatively complex manufacturing process. Typically, two extruders are needed for the exhaust‑type rubber extrusion process. Since producing three‑layer composite sealing strips places high demands on equipment stability, the overall performance and reliability of the rubber‑processing machinery largely determine the quality and effectiveness of the final sealing strip.

Hebei Shuangda Rubber & Plastics Machinery Co., Ltd. is a modern enterprise integrating R&D, 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 extrusion lines, plastic pipe extrusion 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.