Strong nonwoven fabric laminates from engineered multiconstituent fibers

A nonwoven fabric laminate comprising a first layer of thermoplastic filaments formed from a first thermoplastic polymer and a second layer of discrete thermoplastic fibers formed from a second thermoplastic polymer, wherein the layers are positioned in laminar surface-to-surface relationship, wherein the layers are heat bonded in discrete areas, and wherein the thermoplastic polymer in at least one of the layers is a highly dispersed blend of olefin polymers which are present as a dominant continuous phase and at least one noncontinuous phase dispersed therein, with the polymer of said noncontinuous phase or phases having a Polymer Melting Temperature (PMT) of at least 30.degree. C. below the PMT of said continuous phase, and with the dispersed noncontinuous phase or phases occupying a substantial portion of the fiber surfaces.

A nonwoven fabric laminate comprising a first layer of thermoplastic fibers formed from a first thermoplastic polymer and a second layer of thermoplastic fibers formed from a second thermoplastic polymer wherein the layers are positioned in laminar surface-to-surface relationship, wherein the layers are heat bonded in discrete areas, and wherein at least a portion of the thermoplastic fibers in said first layer are multiconstituent fibers formed of highly dispersed blends of at least two different immiscible olefin polymers which are present as a dominant continuous phase and at least one noncontinuous phase dispersed therein, with the polymer of said noncontinuous phase or phases having a Polymer Melting Temperature (PMT) of at least 30.degree. C. below the PMT of said continuous phase, and with the dispersed noncontinuous phase or phases occupying a substantial portion of the fiber surfaces.

A nonwoven fabric laminate comprising in sequence a first layers of thermoplastic filaments formed from a first thermoplastic polymer, a second layer of thermoplastic fibers formed from a second thermoplastic polymer, and a third layer of thermoplastic filaments formed from a third thermoplastic polymer, wherein the layers are heat bonded in discrete areas and wherein each of the first and third thermoplastic polymers is a highly dispersed blend of olefin polymers which are present as a dominant continuous phase and at least one noncontinuous phase dispersed therein, with the polymer of said noncontinuous phase or phases having a polymer melting temperature of at least 30.degree. C. below the polymer melting temperature of said continuous phase, and with the dispersed noncontinuous phase or phases occupying a substantial portion of the fiber surfaces.

A nonwoven fabric laminate comprising a microfibrous inner layer formed of meltblown polypropylene sandwiched between outer layers of spunbonded thermoplastic filaments, wherein the layers are positioned in laminar surface-to-surface relationship and are bonded together in discrete areas, said thermoplastic filaments of said spunbonded outer layers comprising multiconstituent filaments formed of highly dispersed blends of at least two different immiscible olefin polymers which are present as a dominant continuous phase and at least one noncontinuous phase dispersed therein, with the polymer of said noncontinuous phase or phases having a polymer melting temperature of at least 30.degree. C. below the polymer melting temperature of said continuous phase, and with the dispersed noncontinuous phase or phases occupying a substantial portion of the fiber surfaces.

A nonwoven fabric laminate comprising a microfibrous inner layer formed of meltblown polypropylene sandwiched between outer layers of spunbonded thermoplastic filaments, wherein the layers are positioned in laminar surface-to-surface relationship and are heat bonded together in discrete areas, said thermoplastic filaments of said spunbonded outer layers comprising multiconstituent filaments formed of highly dispersed blends of isotactic polypropylene and linear low density polyethylene, with the polypropylene being present as a noncontinuous phase and the polyethylene being present as a noncontinuous phase dispersed therein, with the polymer of said noncontinuous phase having a polymer melting temperature of at least 30.degree. C. below the polymer melting temperature of said continuous phase, and with the dispersed noncontinuous phase occupying a substantial portion of the fiber surfaces.