Patent ID: 8114507

Claim:
A multi-layered fiber comprising: a core having an exterior surface comprising polypropylene; and a skin layer disposed on at least a portion of the core comprising a first polymer and a second polymer, wherein: the first polymer comprises a polymer having at least 70% α-olefin units and is characterized by a melting temperature less than the melting temperature of the exterior surface of the core; and, the second polymer comprises a co-polymer having at least 50% α-olefin units and is characterized by a number-average molecular weight of about 7,000 g/mol to 50,000 g/mol, a viscosity of between about 2,500 and 150,000 cP measured at 170° C., wherein the viscosity of the second polymer is not greater than about 10 percent of the viscosity of the first polymer measured at 170° C., and a melting temperature lower than the melting temperature of the exterior surface of the core; wherein the percentage by weight of the second polymer to the total weight of the fiber is between about 0.25% wt and 50% wt.