Custom Co-Extruded Pinchweld Rubber Seal China Manufacturer
This co-extruded pinchweld rubber seal combines a dense EPDM edge-grip channel with a soft EPDM sponge bulb. The gripping section contains a flexible metal carrier that helps the seal hold securely onto metal, plastic, or composite flanges, while the compressible bulb provides sealing, cushioning, and vibration reduction.
The push-on design allows fast installation without screws or permanent adhesive. Its flexible structure also enables the profile to follow curved and irregular panel edges.
EPDM offers good resistance to weathering, ozone, UV exposure, moisture, aging, and many mild chemicals. It also maintains good flexibility and compression recovery across a wide operating temperature range, making the seal suitable for doors, hatches, windows, equipment covers, and enclosure panels.
Depending on the selected EPDM compound, the seal can operate within a temperature range of approximately -50°C to 120°C.
Product Specifications
| Items | Unit | Result |
| Hardness | shore A | 70+/-5 |
| Tensile Strength | Mpa | >=14 |
| Elongation at Break | % | >=300 |
| Cold Resistance Bend r=30mm -40°Cx24h | Elastic | |
| Corrosivity, tile 80°Cx48h | Non-pollution | |
| change of tensile strength after heat aging 100°Cx72h |
% | >=1°C |
| compression Set 30% 70°Cx24h, recover 0.5h |
% | <=62 |
What Is a Co-Extruded Pinchweld Rubber Seal?
A co-extruded pinchweld rubber seal is an edge-mounted sealing profile made from two or more rubber compounds with different hardness levels.
The lower section is a firm U-shaped gripping channel that fits securely over a flange or panel edge. It may include an internal metal carrier to improve retention and prevent the seal from loosening during use.
The upper sponge bulb is softer and more compressible. When a door, hatch, cover, window, or panel closes, the bulb compresses to help seal the gap against water, dust, air, noise, and vibration.
This combined construction provides both secure attachment and flexible sealing in one profile.
Why Choose Co-Extruded Pinchweld Rubber Seal?
Reinforced Pinchweld Channel
The U-shaped channel grips the edge of a metal, plastic, or composite panel. Internal metal reinforcement can be added to improve holding strength and maintain the profile shape.
Sponge Rubber Bulb
The hollow sponge bulb compresses under closing pressure and returns to its original shape after the pressure is released. It helps accommodate uneven gaps and reduces the force required to close doors or panels.
Flexible Sealing Lip
Some profiles include an additional side lip or sealing fin. This section can cover panel gaps, improve appearance, redirect water, or provide a secondary sealing surface.
The hard gripping section and soft bulb are produced together in one continuous profile. This creates a stable connection between the sections and removes the need for separate assembly.
Frequently Asked Questions
What does pinchweld mean?
A pinchweld is a raised flange or joined panel edge commonly found around vehicle doors, windows, hatches, cabinets, and equipment covers. A pinchweld seal grips directly onto this edge.
Does the seal require adhesive?
Most pinchweld seals rely on the gripping channel and internal carrier for retention. Adhesive is usually unnecessary, although it may be added for specific installations.
What is the sponge bulb used for?
The sponge bulb compresses when a door, hatch, or panel closes. It helps seal gaps and reduce water, dust, air, noise, vibration, and impact.
Can you customize the grip range?
Yes. The channel can be designed for different flange thicknesses. Please provide the minimum and maximum panel thickness.
Can the bulb position be customized?
Yes. The bulb can be positioned on the top, side, or at an angle according to the direction of compression.
Can you manufacture the seal in EPDM?
Yes. EPDM is one of the most common materials for weather-resistant pinchweld seals used outdoors.
Is an internal metal carrier available?
Yes. A flexible metal carrier can be integrated into the gripping channel to improve retention and shape stability.
Can the seal be supplied in continuous rolls?
Yes. Products can be supplied in continuous coils, fixed lengths, or processed components.
What information is required for a quotation?
Please provide the cross-sectional drawing, flange thickness, sealing gap, material, color, length, quantity, application, and operating environment.
U channel Flexible rubber coextrusion profiles
