Poypropylene and Polyethylene

Polypropylene fibers has been used to reinforce flooring products and underlay felts while Polypropylene fibers has been used to reinforce flooring products and underlay felts.

Poypropylene

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.

Polypropylene fibre has the following properties
Tensile strength 200-2000 MPa
Young’s modulus 8-200 GPa
Diameter 1000-4000 micrometers
Specific gravity 0.90-0.91
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

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%
Temoerature limits 225-280%

Substitutes for asbestos – Marcel Cossette