Composite sealing strips are produced by combining multiple materials through the coordinated operation of two or more rubber extruders.

Material

The commonly used material is ethylene propylene diene monomer rubber (EPDM), which boasts excellent weather resistance, heat resistance, and ozone resistance. Some composite sealing strips also incorporate materials such as plastics, steel strips, and glass fibers, or utilize thermoplastic elastomers like TPV and TPE compounded with rubber, to meet diverse performance requirements.

Category

Single-extruded composite sealing strip: This can be considered a pure rubber seal, composed of a single-material rubber.
Double-composite sealing strip: Also known as a two-layer sealing strip, it typically consists of a foamed sponge rubber layer and a dense rubber layer. Often, a metal skeleton material is embedded within the dense rubber layer or arranged along its axial direction.
Three-layer sealing strip: Composed of two dense rubber layers (one of which is light-colored) and a sponge rubber layer. Typically, reinforcing fibers and a metal skeleton are incorporated into the dense rubber layers.
Four-layer sealing strip: Made from four different materials, it features a thin rubber protective layer coated on the surface of a sponge rubber (foam tube), which helps extend its service life.
Soft-hard composite sealing strip: Typically made from silicone rubber, it features a transparent, smooth surface and combines both softness and elasticity. It is non-toxic, odorless, and exhibits excellent resistance to high and low temperatures.

Features

The surface is smooth and aesthetically pleasing, featuring excellent elasticity and resistance to compressive deformation. It exhibits outstanding resistance to weathering, ozone, and chemical agents, and operates effectively over a wide temperature range. For example, composite sealing strips made of EPDM material can withstand temperatures from -40℃ to +120℃, effectively providing waterproofing, dustproofing, sound insulation, thermal insulation, and vibration damping functions.

Application areas

It is widely used in fields such as automobiles, doors and windows curtain walls, household appliances, lighting fixtures, and construction machinery. For example, the door frame seal strip for automobiles is a typical four-layer composite seal strip that effectively seals the gap between the car door and the vehicle body, enhancing in-cabin comfort.