초록 ▼

The invention provides a novel shaped product comprising a sheet material of polyurethane resin material reinforced with binder-free natural-fibre material, such as jute, flax, hemp, coir, ampas, ramie or cotton, possibly combined with polypropylene, polyethylene and/or glass fibres. A preferred fib

The invention provides a novel shaped product comprising a sheet material of polyurethane resin material reinforced with binder-free natural-fibre material, such as jute, flax, hemp, coir, ampas, ramie or cotton, possibly combined with polypropylene, polyethylene and/or glass fibres. A preferred fibre material is jute, preferably in the form of jute needled felt. The invention also provides a process for making the product. In the process, a binder-free mat of natural-fibre material having a water content of at least 4% which is impregnated with a known per se mixture thermosettable to form a polyurethane material, comprising a polyether-polyol component and an isocyanate component, followed by maintaining the temperature of the mixture at 20°-50°C., and setting the impregnated fibrous mat in a closed mold at a pressure of 3.5-20 kg/cm2 and a temperature of 20°-75°C.

대표청구항 ▼

A sandwich panel comprising a core layer firmly bonded on opposite sides to thermoset polyurethane resin sheet material reinforced with cohesive natural fiber material, said sandwich panel having been obtained by combining two sheets of cohesive natural fiber material impregnated with polyurethane r

A sandwich panel comprising a core layer firmly bonded on opposite sides to thermoset polyurethane resin sheet material reinforced with cohesive natural fiber material, said sandwich panel having been obtained by combining two sheets of cohesive natural fiber material impregnated with polyurethane resin with said core layer positioned between said sheets to form a laminate and thermosetting said laminate in a mold to produce said sandwich panel.