Insulating Material

P84 fibres having a unique multilobal cross section which offers a much higher specific surface compared to round fibres are the ideal base material for insulation products.

Needle felts made of P84 polyimide fibres quilted to a light weight P84 fabric are used as thermal insulation inside of fire fighter jackets. The soft handling of P84 in addition to the thermostable and non flammable properties are reasons for their usage in protective clothing.

P84 polyimide fibres show a tendency to shrink extensively if heated above the glass transition temperature of 315 °C. By varying the temperature and the type of initial fibre structure (nonwoven, fabric, knit wear etc.) it is possible to produce light weight but stable mechanical structures which achieve the stiffness of thermoplastic LDPE without additional adhesives or binders. During the heat treatment high contraction forces generate bonds between the single fibres forming self supporting structures.

Using a nonwoven the structure is influenced by the density and thickness of the felt, the temperature of the process and the allowed rate of shrinkage. Achieved densities reach from 0,19 g/cm³ up to 0,96 g/cm³ for semi-rigid to rigid fibre boards. The boards are used in insulation applications in rubber and plastics processing. They are compression resistant and can be machined like wood and easily fabricated into custom insulation packages for areas that could not be insulated without high effort before. Tools for extrusion, thermoset compression and injection molding processing are targets for insulation with this new developed product.

Albany Int. markets rigid insulation boards out of P84 fibres under the brand Pyropel®.