Rubber Extrusions UK 2026: Profiles, Compounds, Standards & How to Specify
What Are Rubber Extrusions?
Rubber extrusions are rubber products manufactured by forcing raw rubber compound through a shaped die to produce continuous lengths with a consistent cross-sectional profile. Unlike moulded rubber (which is formed in a closed cavity) or rubber sheet (flat), extrusions can take virtually any two-dimensional cross-sectional shape — from simple square or round profiles to complex T-sections, P-sections, D-sections, and custom engineered shapes. UK businesses use rubber extrusions in sealing, gasketing, edge protection, weatherstripping, and vibration isolation applications across almost every industry.
How Are Rubber Extrusions Made?
The extrusion process forces uncured rubber through a precision-machined die at elevated temperature. The rubber exits as a continuous length with the die's cross-sectional shape. It is then vulcanised (cured) in an oven or autoclave to achieve its final physical properties — hardness, tensile strength, compression set, and chemical resistance. The result is a dimensionally consistent profile that can be cut to any length required.
Common Rubber Extrusion Profiles
D-Section (Door and Window Seals)
D-section rubber extrusions are the most widely used profile for door and window sealing. The curved "D" compresses when the door or window closes, creating a weathertight seal. Available in solid or hollow (sponge) construction, and in EPDM for outdoor weathering resistance or NBR for fuel-resistant applications.
P-Section (Pillar Seals)
P-sections are used for door pillar seals in vehicles, caravans, and industrial enclosures. The circular bulb compresses against the opposing surface while the flat leg is fixed to the frame.
Square and Rectangular Section
Solid square rubber cord and rectangular strip are used as general-purpose seals, gaskets cut from strip, and vibration isolation pads. Available in NBR, EPDM, silicone, and natural rubber compounds.
T-Section
T-section extrusions are commonly used as edge trims on sheet metal, glass, and panel edges. The T-section clips over the edge to provide a protective and aesthetic finish while preventing contact injury.
U-Channel / Edge Trim
U-channel rubber extrusions grip over panel and glass edges to provide protection and a finished appearance. Widely used in vehicle bodywork, industrial enclosures, and construction.
Hollow (Sponge/Foam) Extrusions
Hollow rubber extrusions — also called sponge or cellular rubber profiles — compress far more easily than solid rubber, making them ideal for low-closure-force applications or where significant gap variation must be accommodated. EPDM sponge extrusions are the standard choice for outdoor door and window sealing in the UK construction industry.
Rubber Extrusion Materials: Which Compound?
| Compound | Key Properties | Typical Extrusion Applications |
|---|---|---|
| EPDM | Excellent UV, ozone, weather resistance; −40°C to +120°C | Outdoor seals, roofing profiles, automotive weatherstrip |
| NBR (Nitrile) | Oil, fuel, and hydrocarbon resistance | Fuel system seals, hydraulic engineering, food equipment |
| Neoprene (CR) | Good weather, oil, and flame resistance; moderate chemical resistance | Marine, HVAC, industrial applications |
| Silicone | Extreme temperature range (−60°C to +230°C); food grade grades available | Oven door seals, pharmaceutical, food processing |
| Natural Rubber (NR) | High resilience and tear resistance | Agricultural equipment, vibration isolation |
| SBR | Good abrasion resistance; economical | General industrial sealing, edge strips |
For compound selection guidance, see our Rubber Compound Comparison Guide UK — SBR vs EPDM vs Nitrile vs Neoprene vs Natural Rubber.
Standard vs Custom Rubber Extrusions
Standard Profiles
Hundreds of standard rubber extrusion profiles are available as stock items — D-sections, square cord, P-sections, U-channels, and round cord in common sizes are held in stock for immediate dispatch. Standard profiles are the fastest and most economical solution for common sealing and edging requirements.
Custom Tooled Extrusions
For non-standard cross-sections, a custom extrusion die is machined to your specification. Tooling costs typically range from £150–£800 depending on profile complexity. Once tooled, the unit cost of custom extrusions is comparable to standard profiles. Custom tooling is cost-effective for recurring requirements of 50 metres or more.
Rubber Extrusions in UK Industries
Construction and Building
EPDM rubber extrusions are extensively used in UK construction for glazing seals, curtain wall gaskets, window and door perimeter seals, and roofing edge trims. The UK construction industry uses millions of linear metres of rubber sealing profiles annually, driven by Building Regulations thermal and acoustic requirements.
Automotive and Transport
Vehicle door seals, glass run channels, bonnet seals, tailgate seals, and body side mouldings are all manufactured as rubber extrusions. Van conversion and horsebox/trailer body builders use extensive lengths of rubber extrusion for weatherproofing and edge protection.
Manufacturing and Engineering
Industrial machine seals, enclosure gaskets, cable entry grommets, and hydraulic system seals use rubber extrusions in nitrile, EPDM, and silicone compounds. Custom profiles are frequently tooled for specific equipment sealing requirements.
Marine and Offshore
Hatch seals, deck edge profiles, and watertight door seals on commercial vessels use neoprene and EPDM extrusions for their UV and saltwater resistance. See our Marine & Offshore Rubber guide for related products.
Food and Pharmaceutical
Silicone rubber extrusions with FDA-compliant, food-grade formulations are used in food processing equipment seals, oven door gaskets, and pharmaceutical clean room door seals. These compounds meet EU Regulation 10/2011 on food contact plastics and FDA 21 CFR requirements.
Rubber Extrusion Tolerances and Standards
Standard dimensional tolerances for rubber extrusions follow BS ISO 3302-1 (Rubber — Tolerances for Products). For most engineering applications, E2 class tolerances (typically ±0.4–1.6mm depending on dimension) are standard. Tighter E1 tolerances are available for precision sealing applications at additional cost.
How to Specify a Rubber Extrusion
When specifying rubber extrusions, provide the following information:
- Cross-section drawing or dimensions — include all critical dimensions with tolerances
- Compound/material — e.g., EPDM 60 Shore A, NBR 70 Shore, Silicone FDA
- Hardness (Shore A) — typically 40–80 Shore A for most sealing applications
- Annual quantity — metres per year for stock profile or custom tooling decision
- Operating conditions — temperature range, exposure to fluids, UV exposure
- Regulatory requirements — food grade, ATEX, medical device, RoHS, etc.
Rubber Draught Excluder Strips
A common form of rubber extrusion used by UK homeowners and businesses is the rubber draught excluder strip — an extruded profile in EPDM, neoprene, or NBR rubber that seals gaps under doors and around window frames to prevent heat loss. Available as self-adhesive strips, screw-fix profiles, and brush seal combinations. See our range of rubber sealing strips.
Frequently Asked Questions
What is the difference between rubber extrusion and rubber moulding?
Extrusion produces a continuous profile of consistent cross-section in any length. Moulding produces individual parts of a defined three-dimensional shape in a closed mould. Extrusions are typically used for seals, strips, and profiles measured in metres; mouldings are used for gaskets, O-rings, grommets, and other discrete components.
Can rubber extrusions be supplied cut to length?
Yes. Most stock rubber extrusions are available cut to any specified length, from 100mm to full 25m or 50m coil lengths. Cut-to-length orders incur a small cutting charge for very short lengths but are otherwise priced per metre.
What is the minimum order for custom rubber extrusions?
For standard profiles, there is typically no minimum order beyond a practical cutting minimum of 1–2 metres. For custom tooled profiles, minimum first-run orders of 25–50 metres are typical, with no minimum on repeat orders once the tool exists.
How long do rubber extrusions last outdoors?
EPDM rubber extrusions are specifically formulated for outdoor use and offer exceptional resistance to UV radiation, ozone, and weathering. EPDM seals correctly installed in a building or vehicle application should last 20–30 years. Avoid NBR or natural rubber for outdoor applications — these degrade rapidly in UV/ozone.
Explore Our Rubber Profile and Sheeting Range
Rubberco stocks an extensive range of rubber sealing profiles, rubber sheet for gasket cutting, and specialist rubber compounds suitable for extrusion-related applications:
- Rubber Sheet UK — EPDM, Nitrile, Neoprene & SBR sheet for gasket cutting
- Rubber Sheeting UK — SBR, EPDM & Nitrile in 10m rolls
- Solid Neoprene Rubber Strip — square and rectangular strip profiles
- Rubber Matting UK — industrial and commercial rubber matting
For custom extrusion profiles and bulk supply, contact our technical team with your drawings and quantity requirements.
