Custom EPDM Rubber Extrusion Seals – Various Profile Shapes for Industrial & Automotive Applications

EPDM compound selection directly affects seal performance in service. We maintain a range of standard formulations covering different hardness levels, curing systems, and performance priorities.

Compound Development and Material Options

EPDM compound selection directly affects seal performance in service. We maintain a range of standard formulations covering different hardness levels, curing systems, and performance priorities. Standard EPDM compounds offer:

Hardness range from 40 to 90 Shore A

Continuous service temperature from -40°C to +120°C

Good resistance to ozone, UV exposure, weathering, and polar fluids including brake fluids and phosphate esters

Compression set values typically below 25% after 70 hours at 100°C per ASTM D395 Method B

For applications with specific chemical exposure, temperature extremes, or regulatory requirements, we adjust the base polymer, filler system, plasticizer, and cure package accordingly. FDA-compliant compounds are available for applications requiring food-contact compliance. Low-fogging formulations can be supplied for automotive interior components. Color matching is available beyond standard black, though custom colors may affect material cost and lead time.

Extrusion and Vulcanization Process

Rubber compound is prepared through internal mixing and mill processing to achieve uniform dispersion of ingredients. Pre-formed rubber stock is fed into the extruder, heated, and forced through the precision-machined die to form the continuous profile. The extrudate then passes through a continuous vulcanization system.

For solid EPDM profiles, we use hot air curing tunnels or liquid salt bath (LCM) vulcanization depending on profile geometry and surface finish requirements. Sponge EPDM profiles are vulcanized in microwave heating tunnels followed by hot air post-cure to achieve consistent cell structure and dimensional stability. Co-extruded profiles use multi-zone extrusion heads and synchronized curing to bond different rubber compounds into a single integrated profile.

Line speed, temperature profiles, and tension control are adjusted for each profile geometry to minimize dimensional variation and surface defects. Profiles requiring precise length control are cut using automated cutting systems. For profiles supplied in coils, we control coil diameter and packaging to prevent deformation during storage and transport.

Splicing and Fabrication Services

Many sealing applications require endless loops or frames rather than straight lengths. We provide vulcanized splicing services to join extruded profiles into continuous rings, rectangles, or custom-shaped frames. Splice strength is verified through tensile testing and typically achieves 80% or higher of base material strength when properly executed.

Additional fabrication operations include:

Punching holes or slots for fastener access

Notching for corner bending applications

Applying adhesive backing (3M or equivalent pressure-sensitive tape)

Flocking with nylon fiber for sliding door and window applications

Installing plastic or metal end caps

Assembly with metal clips, retainers, or fasteners

Typical Profile Types We Produce

Our production covers a broad range of standard and custom profile geometries:

Weatherstrip seals: bulb seals, hollow tube profiles, and lip seals for doors, hoods, and trunk lids

Glazing seals: U-channel profiles with or without metal reinforcement for glass retention

Edge trim seals: rubber-covered metal carriers with sealing lips for panel edges

Compression gaskets: solid or sponge profiles designed for flange or panel compression sealing

Retention profiles: profiles with barbed or anchor features for press-fit installation into metal or plastic channels

Complex co-extrusions: profiles combining hard carrier sections with soft sealing lips, or dense rubber with sponge sealing bulbs