Patent attributes
A method of consolidating thermoplastic fibrous layers by providing a plurality of fibers having a core with an exterior surface portion comprising polypropylene and a first layer disposed on at least a portion of the core containing at least 70% alpha-olefin units which is formed into a first fibrous layer. A second fibrous layer is applied to the first fibrous layer which second layer contains a second polymer being a co-polymer having at least 50% alpha-olefin units which is characterized by a number-average molecular weight of about 7,000 to 50,000 g/mol, a viscosity of between about 2,500 and 150,000 cP measured at 170° C. and a melting temperature lower than the melting temperature of the exterior surface of the core. Heat and optionally pressure are applied to the assembly to consolidate the layers.
