IIT technology and composites

The first intumescent system able to work in composite structures

The IIT technology can offer two forms of protection for the growing fire protection demands of the composite market. The first is the IIT powder incorporated into the resin matrix. The alternative system is the IIT coatings, particularly the PD63 range.

IIT powder is the first system to offer true intumescent protection in composite systems. These products are marketed as Phyrolex HMED and MDD

Due to the lower activation temperature the IIT powder is able to intumesce and protect the substrate before it starts to burn. This means that the smoke emission is significantly reduced and the length of time before the composite structure suffers structural collapse is greatly increased.

The IIT powder is able to work in a wide range of composite systems including polyester, epoxy and polyurethane. The powder has shown great potential in polyester SMC and BMC as well as normal layup techniques. It works very well in epoxy when used in pultrusion or prepreg manufacture and in polyurethane it is showing equally good performance.

The range of tests that IIT powder can pass is always evolving but currently we can offer systems to pass most tests from a UL94 up to a BS476 Part 20-22 barrier test with polyester.  The key points are:

  • Lower S.G than any other flame retardant
  • Much lower loading than Aluminium trihydrate
  • Works synergistically with Aluminium trihydrate.
  • Is available in a wide range of particle sizes
  • Is halogen free
  • Low toxicity
  • Shows little to no detriment in the physical properties
  • Loading will varying depending on the substrate and the fire test requirements

The coatings based on the IIT technology have some advantages over the powder system and are already producing an excellent track record for fire performance:

  • A coating system requires no modification to the resin matrix or processing techniques.
  • There is no loss of physical properties- a coated composite will always be lighter and stronger than a composite where the FR is incorporated into the resin matrix.
  • The smoke production is far lower than any composite that has the FR incorporated into the resin- the resin will always contribute smoke and heat to the system, the coatings prevent the resin getting hot enough to do this.