Patent ID: 6942748
Filing Date: 2005-09-13
Classification: A61F,B32B,Y10T

Abstract:
1. A method for forming a finished product incorporating a tear resistant laminate, comprising: (a) selecting an elastic polymeric film having a basis weight of from about 18 g/m2 to about 100 g/m2; (b) selecting a first precursor nonwoven web formed of randomly disposed nonelastomeric thermoplastic fibers and having predefined machine and transverse directions, wherein the first precursor nonwoven web is selected so that at least 10% of the fibers of the first precursor nonwoven web have a softening temperature approximately equal to a predetermined softening temperature; (c) heating the first precursor nonwoven web to a temperature between the predetermined softening temperature and the melting temperature of any of the fibers of the first precursor nonwoven web; (d) drawing the heated first precursor nonwoven web under tension in said predefined machine direction to cause the first precursor nonwoven web to be longitudinally elongated in said machine direction and consolidated laterally in said predefined transverse direction, thereby forming a first nonwoven web; (e) cooling the first nonwoven web whereby the first nonwoven web is consolidated in said transverse direction, and has an extensible elongation value in said transverse direction of from about 20% to about 200% and an ultimate force to break in said transverse direction of greater than about 1500 g/in.; (f) selecting a second precursor nonwoven web formed of randomly disposed nonelastomeric thermoplastic fibers and having predefined machine and transverse directions, wherein the second precursor nonwoven web is selected so that at least 10% of the fibers of the second precursor nonwoven web have a softening temperature approximately equal to the predetermined softening temperature; (g) heating the second precursor nonwoven web to a temperature between the predetermined softening temperature and the melting temperature of any of the fibers of the nonwoven web; (h) drawing the heated second precursor nonwoven web under tension in said predefined machine direction to cause the second precursor nonwoven web to be longitudinally elongated in said machine direction and consolidated laterally in said predefined transverse direction, thereby forming a second nonwoven web; (i) cooling the second nonwoven web whereby said second nonwoven web is consolidated in said transverse direction, and has an extensible elongation value in said transverse direction of from about 20% to about 200% and an ultimate force to break in said transverse direction of greater than about 1500 g/in.; (j) bonding a bottom surface of the first nonwoven web to a top surface of the elastic polymeric film and simultaneously bonding a top surface of the second nonwoven web to a bottom surface of the elastic polymeric film to produce a tear resistant laminate; and (k) incorporating the tear-resistant laminate into a finished product without further substantial necking of the laminate.