VIP’s tunnel segment gaskets are manufactured in our Cambridgeshire headquarters in the UK, which is certified by The British Standards Institute to ISO 9001, using the latest manufacturing equipment and processes.


VIP compounds its own rubber at our on-site mixing facility to proven formulations developed by VIP’s rubber technologists. The compounds used meet WRAS and other internationally recognised standards where required.

VIP Rubber Compounding

Predominantly EPDM is the rubber of choice for tunnel segment gaskets as it provides the sealing and material qualities required. However in instances where resistance to more aggressive chemicals is required, VIP can compound and manufacture using NBR (Nitrile).


A study carried out by Loughborough University in the UK on behalf of VIP concludes that one of the major elements affecting the gaskets’ long term sealing ability is ‘Stress-Relaxation’. This is the measurement of the force that a compressed gasket exerts over time which is crucial to the sealing performance.


EPDM Long Term Stress Relaxation Chart

The research also revealed that with correctly formulated and processed rubber, as supplied by VIP, the life expectancy of our gaskets is in excess of 120 years.


To begin the manufacturing process, VIP’s gasket profiles are extruded through one of the most modern microwave curing lines. This manufacturing technique creates the profile length by forcing the rubber through a die prior to curing. This is then cut to lengths determined by the segment requirements.

TSG Profile Extrusion


All VIP’s corner joints can be manufactured in obtuse, acute and 90° angles to perfectly fit with the corresponding segments.

Using the latest laser guided cutting technology enables virtually any joint angle to be achieved and their design ensures that the sealing properties and closure forces match the extruded gasket section.


In order to ensure the final product meets the high standards set by VIP, physical checks are made by our quality team both during the manufacture process and on final completed gaskets against:

  • Profile Size – to ensure a consistent profile shape during the extrusion process
  • Joint Integrity – to check the strength of moulded joints
  • Geometric Requirements – to check the shape of the finished gasket meets the segment design requirements

VIP’s TSG Manufacturing Facilities

  • Rubber compounded on site and tested prior to use
  • Can manufacture from EPDM and NBR
  • State of the art extrusion facilities
  • Corners can be manufactured to any angle
  • Multiple quality checks undertaken throughout the manufacturing process
  • Certified to British Standard ISO 9001