SELFBONDED NONWOVEN FABRICS FROM HETEROFILS WITH HIGH DENSITY POLYETHYLENE SHEATH

摘要

Disclosed are selfbonded nonwoven fabrics eminently suitable for civil engineering applications such as unpaved road underlay material. The fabrics comprise at least 70 weight percent of sheath/core heterofilaments having a core of isotactic polypropylene in which the sheaths are high density polyethylene in an amount of 5 to 30 weight percent of the heterofilaments. Up to 30 weight percent of other fibers, natural or synthetic, may be included in the fabric. The claimed fabrics have outstanding combinations of strength, fatigue resistance, and tear resistance; and are far superior in this regard than corresponding fabrics based upon low density polyethylene sheaths. The method of preparation includes melt spinning substantially concentric foregoing heterofilaments; drawing the heterofilaments at a ratio in the range of 2-6; pneumatically laying the filaments to form an unbonded web; and selfbonding the web under pressure and at a fabric temperature of from 120 to 155.degree.C.