⚡ Need a Custom Dual-Hardness Seal or Clip-On Extrusion?

Eliminating mechanical clips, separate fasteners, and adhesives? Accuseal Rubber engineers and manufactures custom dual-durometer co-extrusions in-house at our New Jersey facility—integrating rigid structural bases with ultra-soft sealing bulbs into a single cohesive profile.

➔ Upload Your CAD Drawing (.STEP / .DWG / PDF) for a Rapid 24-Hour Engineering RFQ

What Is Dual-Durometer Co-Extrusion?

Direct Answer: Dual-durometer co-extrusion is an advanced manufacturing process that feeds two distinct elastomeric compounds—typically one rigid or semi-rigid elastomer and one soft, highly compliant rubber—simultaneously through a single, specialized extrusion die. Under controlled thermal curing and pressure, the two compounds form a molecularly vulcanized bond, creating a single integrated profile that requires no glues, metal clips, or secondary assembly steps.

Engineers specify dual-hardness seals when an assembly requires a stiff structural foundation (e.g., 70–80 Shore A or rigid plastic core) to snap securely onto a flange or sheet metal edge, paired with an ultra-soft sealing bulb (e.g., 20–40 Shore A or closed-cell sponge) that compresses under minimal latching force.

The Co-Extrusion Advantage: Single Profile vs. Two-Piece Assemblies

Traditional edge sealing often requires two distinct components: a rigid plastic/metal mounting retainer and a soft foam gasket held together by adhesives or mechanical rivets. Dual-durometer co-extrusion replaces this multi-step workflow.

Common Dual-Durometer Geometries & Cross-Sections

At Accuseal Rubber, our in-house wire EDM die tooling allows us to formulate custom dual-geometry profiles tailored to your sheet metal thickness and enclosure tolerances:

• Rigid U-Channel with Soft Sealing Bulb: A semi-rigid 70–80 Shore A U-channel (with internal gripping lips) that snaps friction-tight onto raw metal edges, coupled with a hollow sponge or soft silicone bulb to create weather-tight door and hatch closures.

• Rigid Base P-Seals: A dense mounting spine engineered for track-channel insertion, paired with a dynamic sealing loop that absorbs continuous door slam fatigue.

• Dual-Shore Flange Gaskets: High-durometer base designed to resist bolt torque deformation combined with a soft inner sealing bead to prevent fluid bypass under light clamping pressure.

• Dual-Color & Conductive Co-Extrusions: Inner conductive silicone core for EMI/RFI shielding combined with an outer non-conductive, weather-resistant silicone jacket for cost-efficient electronic enclosures.

Material Compounds & Hardness Combinations

Accuseal Rubber co-extrudes high-performance elastomeric polymers compounded to meet specific industrial, thermal, and regulatory requirements:

RMA Precision Tolerances for Dual-Durometer Extrusions

Extruding two elastomeric streams with disparate flow rates, viscosities, and shrinkage rates requires precise die-land balancing. Accuseal Rubber manufactures co-extruded profiles adhering to RMA (Rubber Manufacturers Association) standards:

• RMA Class 1 (High Precision): Applied to critical aerospace cockpit seals, optical instrument housings, and medical enclosures where channel dimensions and bulb deflection must be held to fractions of a millimeter.

• RMA Class 2 (Precision): The industry standard for automotive door trims, solar panel framing, heavy equipment cabs, and NEMA/IP electrical enclosures.

Every production batch is dimensionally verified using digital optical comparators to ensure proper bulb wall thickness and channel retention force across multi-thousand-foot runs.

In-House Tooling & Secondary Fabrication Services

Accuseal Rubber provides turnkey manufacturing and post-extrusion fabrication under one roof in New Jersey:

1. In-House Wire EDM Die Tooling: Dual-feed co-extrusion die heads engineered and tuned on-site, slashing tooling turnaround down to 1–2 weeks.

2. Pressure-Sensitive Adhesive (PSA) Application: Application of heat-activated high-bond acrylic tapes (e.g., 3M) to the mounting base for high-vibration applications.

3. Corner Vulcanization & Endless Splicing: Custom 90-degree molded corner joints for seamless, ready-to-mount rectangular door frames.

4. Precision Automated Cutting: Exact cut-to-length pieces, slotted drain notches, and punched mounting holes.

Frequently Asked Questions (FAQ)

Can the two materials in a co-extruded profile separate or delaminate over time?

No. Because both elastomeric compounds are co-extruded in their uncured state and undergo vulcanization together in the continuous curing line, the bond is molecular. The interface between the rigid base and the flexible bulb is as strong as the elastomeric compound itself.

Can dual-durometer extrusions be manufactured with metal reinforcement?

Yes. For applications requiring extreme push-on grip along heavy steel flanges (such as truck cabins or generator enclosures), we can integrate internal segmented steel or wire carriers into the rigid base section.

What information is needed to quote a custom co-extrusion profile?

We require your target flange or edge thickness, available latching or closure gap, environmental exposures (temperature, chemicals, outdoor UV), and a 2D or 3D CAD drawing (.STEP, .DWG, or engineering PDF) highlighting the rigid and flexible zones.

Request an Engineering Review & Co-Extrusion Quote

Simplify your assembly line and improve sealing longevity with custom dual-durometer extrusions from Accuseal Rubber Inc.

• Email Specs & CAD: info@accusealrubber.com

• Manufacturing Facility: 18-F Home News Row, New Brunswick, NJ 08901, USA

• Direct RFQ: Submit your CAD drawing (.STEP / .DWG / PDF) for a prompt technical review and pricing quote within 24 hours.