Subscribe to our newsletter to receive the latest news and events from TWI:

Subscribe >
Skip to content

Polymer Testing

TWI has the capability to carry out mechanical testing and assessment on welded polymers using a comprehensive range of techniques and equipment.

We have experience and facilities to carry out mechanical testing of polymer welds, including pipes up to 415mm in diameter:

  • Bend
  • Tensile
  • Peel
  • Tensile impact
  • Dynamic mechanical
  • Whole component/bespoke
  • Whole pipe creep rupture
  • Accelerated ageing
  • Crush testing

Objectives of testing

Tests and analysis in this area can benefit Members and wider industry in a number of ways. Through our work in welded polymer testing we aim to:

  • Develop flaw acceptance criteria and service life prediction for plastic welds
  • Support the development of standards both in the area of plastic pipes and for moulded plastic components
  • Encourage the adoption of Engineering Critical Assessment (ECA) as a concept in the field of welded plastic fabrications and components. This is being done alongside the development of reliable non-destructive testing techniques
  • Support research and development into plastics welding process development and optimisation.

Recent projects

Recent projects undertaken include:

Polytest – Development of phased array ultrasonic non-destructive examination (NDE) for joints in plastic pipes.

PolyTank – Development of phased array ultrasonic NDE for joints in polyethylene storage tanks.

Core research programme – Effect of Forced Cooling on Welds in PE Pipes.

Standards activities

TWI is represented on the following standards committees:

  • ISO TC138/SC5/WG17 (Plastics Pipes, Fittings and Valves, Alternative Test Methods)
  • CEN TC249/WG16 (Thermoplastics Welding)

Standards published:

  • EN 12814-1:2000 (Bend test)
  • EN 12814-2:2000 (Tensile test)
  • EN 12814-3:2014 (Tensile creep test)
  • EN 12814-4:2001 (Peel test)
  • EN 12814-6:2000 (Low temperature tensile test)
  • EN 12814-7:2002 (Tensile test with waisted test specimens)
  • EN 12814-8:2001 (Requirements)

For more information, please email

For more information please email: