초록 ▼

A process is provided for making a water-impermeable, vapor-permeable fabric. A lightweight continuous coating of polypropylene resin is applied to the surface of a fibrous sheet to make the sheet impermeable to water and vapor. Subsequent calendering provides vapor permeability to the sheet while m

A process is provided for making a water-impermeable, vapor-permeable fabric. A lightweight continuous coating of polypropylene resin is applied to the surface of a fibrous sheet to make the sheet impermeable to water and vapor. Subsequent calendering provides vapor permeability to the sheet while maintaining liquid water impermeability. The resultant product is particularly suited for use as a roofing-tile underlayment or as an air-infiltration barrier.

대표청구항 ▼

A vapor-permeable, liquid-water-impermeable fabric which consists essentially of a coated fibrous base sheet of polypropylene or polyester filaments weighing in the range of 50 to 125 g/m2, the filaments having a dtex per filament in the range of 1 to 20, and at least one flat surface of the fibrou

A vapor-permeable, liquid-water-impermeable fabric which consists essentially of a coated fibrous base sheet of polypropylene or polyester filaments weighing in the range of 50 to 125 g/m2, the filaments having a dtex per filament in the range of 1 to 20, and at least one flat surface of the fibrous base sheet having a calendered coating layer of polypropylene which has a melt flow rate in the range of 30 to 150, the coating layer having a unit weight in the range of 5 to 15 g/m2 and containing a multiplicity of small pores which permit substantial flow of gas, but prevent substantial flow of liquid water, the fabric having a moisture vapor transmission of at least 200 g/m2/day and a hydrostatic head of at least 20 cm.