- Material: XPE foam (chemical cross-linked polyethylene)
- Expansion ratio: 3–40 times (26.8–300 kg/m³)
- Thickness: single-layer 3–15 mm; thermally laminated (multi-layer) 15–200 mm
- Width: 500–2000 mm (width can be customized)
- Colour: black, white, gray (colour can be customized)
- Cross-linking: chemical
Customization
Made to order: density, thickness, colour and shape to your drawing. Die-cutting, CNC routing, lamination to film or fabric, slitting and adhesive coating all run in-house, so the part we quote is a finished part, not just a sheet. How a custom part is cut and routed explains what to send with the drawing.
Regular material: MOQ 1,000 m², lead time 15–20 days from order confirmation. Custom parts are quoted from the drawing. A4 samples are free, shipping included.
Water gets into a tunnel at the joints. Segmental linings, construction joints and movement joints are all places where the structure is not continuous, and each one is a path for groundwater unless something compressible fills it. Tunnel seam splicing foam is placed in the gap before the concrete is poured, compresses as the joint closes, and stays compressed to hold the seal.
Features
- Elastic recovery – springs back after compression, so the joint stays filled even as the structure moves.
- Compressible – takes up the tolerance in the joint rather than forcing the concrete apart.
- Weather and chemical resistance – resists temperature cycling and the chemical attack a tunnel environment presents. For exposed outdoor sections, specify a UV-stabilised grade.
- Water-resistant – closes the joint against water penetration.
- Vapour permeable – lets water vapour escape so that condensation does not build up behind the seal.
- No special tooling – installed by hand, which matters on a tunnel programme where access is difficult.
Applications
- New tunnel construction – placed between formwork before the concrete pour, forming a continuous joint once the concrete has cured.
- Section joints – sealing between successive lining sections to keep the structure continuous.
- Tunnel rehabilitation – filling cracks and replacing failed sealants in ageing tunnels with leakage problems.
- Underground space – underground car parks and commercial concourses, not only road and rail tunnels.
Specifications for tunnel seam splicing foam
A tunnel or shaft joint strip has to follow an irregular seam, stay watertight and take movement between the segments.
| Foam | Expansion | Apparent density | Single-layer thickness | Why this grade |
|---|---|---|---|---|
| XPE | 10–20× | 50–100 kg/m³ | 3–15 mm | Water absorption no more than 0.2% with a tear strength of 2.5–6 kN/m, so the strip survives being pulled into a moving joint. |
| IXPE | 20–30× | 33.3–50 kg/m³ | 0.1–15 mm | More conformable sheet where the seam is uneven and the strip has to follow it closely. |
Base material specifications are on the XPE, IXPE and IXPP material pages; finished products are on the XPE foam and IXPE foam pages. Tell us the load, the space available and the service temperature and we will confirm the grade against your drawing.
Why Choose Bofeng Foam
- Closed-cell foam that compresses and recovers rather than taking a permanent set.
- Cut to the joint profile and width you specify.
- Water-resistant with vapour permeability, so the joint does not trap moisture.
- Supplied in the density and thickness matched to your joint movement.
- Samples and specification sheets available before production.
In-house conversion. The strip has to fit the joint, so we cut it to the profile and width you specify and can slit it from sheet to the exact lap width; where the seam is uneven, the more conformable IXPE follows it closely. Regular material starts at 1,000 m²; strip cut to the joint profile is quoted from the drawing.
What closed-cell foam actually absorbs, and why water-resistant is not waterproof, is measured in our water absorption guide.
Conclusion & Inquiry
Flooring foam covers the construction and insulation range, and building construction foam covers the wider sealing applications above ground. Contact us with your joint detail and movement allowance and we will quote a supply.
