Polypropylene fibers and shredded films have been used to reinforce flooring products and underlay felts. The products obtained were excellent except with regard to dimensional stability under humid conditions, and problems of sticking during manufacturing operation. Polypropylene fibres are also used in gaskets and seals.
The cost of polypropylene fibre (as low as 2,50$/kg) is about two to six times the cost of the asbestos it replaces.
|Tensile strength||200-2000 MPa|
|Young’s modulus||8-200 GPa|
|Elongation at break||14-120%|
|Temperatore limit||2850 C|
In comparison with chrysotile asbestos, polypropylene fibre is adequate with regard to availability and chemical resistance. It is at a disadvantage regarding cost, reinforcing strength (strength imparted) and heat resistance.
Polyethylene fibre has not displaced asbestos as a fibre-cement reinforcement because it’s young’s modulus is too low. New linear polyethylene fibres with a modulus of 70 GPa are too costly for use in building materials. Polyethylene fibres have a limited application in gaskets.
Polyethylene felts have been tried as a substitute for chrysotile asbestos felts for use as pipeline wrap. They proved ineffective in retarding the corrosion of the pipelines.
Polyethylene fibre has the following properties
|Specific gravity||0.92 – 0.96|
|Tensile strength||76-620 MPa|
|Elongation at break||10-80%|