US5443606A — Post-treatment of laminated nonwoven cellulosic f…

Claim 1

Independent Claim 161 words

A planar nonwoven elastic web made from a laminated precursor nonwoven web which planar nonwoven elastic web is of reduced maximum pore size relative to the precursor nonwoven web, comprising first and second layers of randomly deposited nonelastomeric thermoplastic man-made fibers and a third layer of cellulose-based staple fibers sandwiched between said first and second layers, said web being uniaxially drawn and heat set wherein the uniaxial heating and drawing are carried out continuously by passing the precursor web through a lateral strain mechanism, whereby a majority of the thermoplastic fibers are aligned transverse to the direction of draw and a minority of segments of thermoplastic fibers are disposed lengthwise to the direction of draw, whereby the web is consolidated in the longitudinal direction and characterized by a maximum pore size of less than 80% that of the precursor web and has an elasticity in the longitudinal direction of at least 70% recovery from a 50% elongation in the longitudinal direction.

Claim 2

Dependent Claim 161 words

A planar nonwoven elastic web made from a laminated precursor nonwoven web which planar nonwoven elastic web is of reduced maximum pore size relative to the precursor nonwoven web, comprising first and second layers of randomly deposited nonelastomeric thermoplastic man-made fibers and a third layer of cellulose-based staple fibers sandwiched between said first and second layers, said web being uniaxially drawn and heat set wherein the uniaxial heating and drawing are carried out continuously by passing the precursor web through a lateral strain mechanism, whereby a majority of the thermoplastic fibers are aligned transverse to the direction of draw and a minority of segments of thermoplastic fibers are disposed lengthwise to the direction of draw, whereby the web is consolidated in the longitudinal direction and characterized by a maximum pore size of less than 80% that of the precursor web and has an elasticity in the longitudinal direction of at least 70% recovery from a 50% elongation in the longitudinal direction.

Claim 3

Dependent Claim 35 words

The nonwoven web of claim 1 wherein the first and second layers of said precursor web are composed of nonelastomeric thermoplastic meltblown fibers randomly bonded and having an average diameter of 0.5 to 8 microns.

Claim 4

Dependent Claim 22 words

The nonwoven web of claim 2 wherein the nonwoven web has a mean flow pore size of between 3 to 40 microns.

Claim 5

Dependent Claim 25 words

The nonwoven web of claim 1 wherein the fibers are at least partially coated with a surfactant for increasing the water wettability of the web.

Claim 6

Dependent Claim 43 words

The nonwoven web of claim 1 wherein said precursor web passes into the lateral strain mechanism at a first linear velocity and exits the lateral strain mechanism at a second linear velocity, and wherein said first velocity is greater than said second velocity.

Claim 7

Dependent Claim 45 words

The nonwoven web of claim 1 wherein the thermoplastic is selected from the group consisting of polyesters, polyamides, cellulose triacetate, cellulose diacetate, poly-4-methylpentene-1, polyphenylene sulfide, liquid crystal polymers, fluoropolymers, and polyolefin, which polyolefin is selected from the group consisting of polypropylene, polyethylene, and copolymers thereof.

Claim 8

Dependent Claim 166 words

A planar nonwoven elastic web made from a precursor nonwoven web which planar nonwoven elastic web is of reduced maximum pore size relative to the precursor nonwoven web, said precursor comprising a lamination of first and second individual nonwoven webs having nonelastomeric thermoplastic man-made fibers and a third layer sandwiched between said first and second layers of cellulose-based staple natural fibers and being uniaxially drawn and heat set, wherein the uniaxial heating and drawing are carried out continuously by passing the precursor web, while heated, through a lateral strain mechanism, whereby a majority of the fibers are aligned transverse to the direction of draw and a minority of segments of fibers are disposed longitudinal to the direction of draw, whereby the web is consolidated in the longitudinal direction and characterized by a maximum pore size of less than 80% that of the precursor web and has an elasticity in the longitudinal direction defined by at least 70% recovery from a 50% elongation in the longitudinal direction.

Claim 9

Dependent Claim 166 words

A planar nonwoven elastic web made from a precursor nonwoven web which planar nonwoven elastic web is of reduced maximum pore size relative to the precursor nonwoven web, said precursor comprising a lamination of first and second individual nonwoven webs having nonelastomeric thermoplastic man-made fibers and a third layer sandwiched between said first and second layers of cellulose-based staple natural fibers and being uniaxially drawn and heat set, wherein the uniaxial heating and drawing are carried out continuously by passing the precursor web, while heated, through a lateral strain mechanism, whereby a majority of the fibers are aligned transverse to the direction of draw and a minority of segments of fibers are disposed longitudinal to the direction of draw, whereby the web is consolidated in the longitudinal direction and characterized by a maximum pore size of less than 80% that of the precursor web and has an elasticity in the longitudinal direction defined by at least 70% recovery from a 50% elongation in the longitudinal direction.

Claim 10

Dependent Claim 43 words

The nonwoven web of claim 7 wherein said precursor web passes into the lateral strain mechanism at a first linear velocity and exits the lateral strain mechanism at a second linear velocity, and wherein said first velocity is greater than said second velocity.

Claim 11

Dependent Claim 45 words

The nonwoven web of claim 7 wherein the thermoplastic is selected from the group consisting of polyesters, polyamides, cellulose triacetate, cellulose diacetate, poly-4-methylpentene-1, polyphenylene sulfide, liquid crystal polymers, fluoropolymers, and polyolefin, which polyolefin is selected from the group consisting of polypropylene, polyethylene, and copolymers thereof.

Claim 12

Dependent Claim 167 words

A longitudinally extending nonwoven planar elastic web which is made from a laminate precursor nonwoven web and of reduced maximum pore size relative to the precursor nonwoven web having nonelastomeric, thermoplastic fibers and cellulose-based staple natural fibers characterized in that the majority of the fibers have been consolidated in the longitudinal direction of the web and are disposed generally in a direction transverse the longitudinal direction of the web, wherein the consolidation of the web is carried out by passing the precursor web, while heated, through a lateral strain mechanism, whereby the maximum pore size of the web represents less than 80% of the maximum pore size of the precursor web and, a majority of the fibers in the web extend transverse the longitudinal direction of the web and a portion of which are bonded to the longitudinal fibers, said web further being characterized as having a level of elasticity defined by at least 70% recovery from a 50% elongation in the longitudinal direction of the web.

Claim 13

Dependent Claim 167 words

A longitudinally extending nonwoven planar elastic web which is made from a laminate precursor nonwoven web and of reduced maximum pore size relative to the precursor nonwoven web having nonelastomeric, thermoplastic fibers and cellulose-based staple natural fibers characterized in that the majority of the fibers have been consolidated in the longitudinal direction of the web and are disposed generally in a direction transverse the longitudinal direction of the web, wherein the consolidation of the web is carried out by passing the precursor web, while heated, through a lateral strain mechanism, whereby the maximum pore size of the web represents less than 80% of the maximum pore size of the precursor web and, a majority of the fibers in the web extend transverse the longitudinal direction of the web and a portion of which are bonded to the longitudinal fibers, said web further being characterized as having a level of elasticity defined by at least 70% recovery from a 50% elongation in the longitudinal direction of the web.

Claim 14

Dependent Claim 9 words

A filter comprising the nonwoven web of claim 10.

Claim 15

Dependent Claim 9 words

A face mask comprising the filter of claim 11.

Claim 16

Dependent Claim 15 words

The nonwoven web as defined in claim 10 wherein the fibers contain an electrostatic charge.

Claim 17

Dependent Claim 17 words

The nonwoven web as defined in claim 10 wherein the web has an electrostatic charge applied thereto.

Claim 18

Dependent Claim 43 words

The nonwoven web of claim 10 wherein said precursor web passes into the lateral strain mechanism at a first linear velocity and exits the lateral strain mechanism at a second linear velocity, and wherein said first velocity is greater than said second velocity.

Claim 19

Dependent Claim 45 words

The nonwoven web of claim 10 wherein the thermoplastic is selected from the group consisting of polyesters, polyamides, cellulose triacetate, cellulose diacetate, poly-4-methylpentene-1, polyphenylene sulfide, liquid crystal polymers, fluoropolymers, and polyolefin, which polyolefin is selected from the group consisting of polypropylene, polyethylene, and copolymers thereof.

Claim 20

Dependent Claim 89 words

A longitudinally consolidated, planar, nonwoven, longitudinally extending elastic web which includes nonelastic thermoplastic fibers, made by the method comprising, heating the web to a temperature between the softening temperature and the melting temperature of the thermoplastic fibers while moving-the web forward in a longitudinal direction, grasping opposing side margins of the heated web and exerting a lateral strain upon the heated web while continuing to move the web forward in a longitudinal direction, and obtaining a longitudinally consolidated, planar, nonwoven, longitudinally extending elastic web which includes nonelastic thermoplastic fibers.

Claim 21

Dependent Claim 89 words

A longitudinally consolidated, planar, nonwoven, longitudinally extending elastic web which includes nonelastic thermoplastic fibers, made by the method comprising, heating the web to a temperature between the softening temperature and the melting temperature of the thermoplastic fibers while moving-the web forward in a longitudinal direction, grasping opposing side margins of the heated web and exerting a lateral strain upon the heated web while continuing to move the web forward in a longitudinal direction, and obtaining a longitudinally consolidated, planar, nonwoven, longitudinally extending elastic web which includes nonelastic thermoplastic fibers.

Claim 22

Dependent Claim 45 words

The consolidated web of claim 17 wherein the thermoplastic is selected from the group consisting of polyesters, polyamides, cellulose triacetate, cellulose diacetate, poly-4-methylpentene-1, polyphenylene sulfide, liquid crystal polymers, fluoropolymers, and polyolefin, which polyolefin is selected from the group consisting of polypropylene, polyethylene, and copolymers thereof.

Claim 23

Dependent Claim 31 words

The consolidated web of claim 18 wherein the consolidated web has an elasticity in the cross direction defined by at least 70% recovery from a 50% elongation in the longitudinal direction.

Claim 24

Dependent Claim 35 words

The consolidated web of claim 19 wherein the consolidated web is characterized by a maximum pore size of less than 80% that of the web prior to said heating and exerting of a lateral strain.

Claim 25

Independent Claim 195 words

A method for treating a nonwoven web which comprises the steps of: (a) selecting a precursor nonwoven web made of first and second layers each of randomly collected nonelastomeric thermoplastic fibers having a crystallinity of at least 30%, each of said first and second layers having a maximum processing draw ratio at break of less than 4 at a temperature at least 10° F. less than the melting point of the thermoplastic and at a strain rate of at least 2500%/min, and a maximum pore size measure of from 4 to 250 microns based on ASTM F 316-86, and a third layer; (b) heating the precursor web at a temperature between the softening temperature and melting temperature of the thermoplastic; (c) drawing the heated precursor web under tension in a substantially lateral direction to cause the web to consolidate longitudinally and thereby reduce the maximum pore size measure of the web by at least 20%, wherein the heating and drawing steps are carried out continuously by passing the precursor web, while heated, through a lateral strain mechanism; (d) obtaining a longitudinally consolidated planar web; and (e) cooling the web or permitting the web to cool.

Claim 26

Independent Claim 195 words

A method for treating a nonwoven web which comprises the steps of: (a) selecting a precursor nonwoven web made of first and second layers each of randomly collected nonelastomeric thermoplastic fibers having a crystallinity of at least 30%, each of said first and second layers having a maximum processing draw ratio at break of less than 4 at a temperature at least 10° F. less than the melting point of the thermoplastic and at a strain rate of at least 2500%/min, and a maximum pore size measure of from 4 to 250 microns based on ASTM F 316-86, and a third layer; (b) heating the precursor web at a temperature between the softening temperature and melting temperature of the thermoplastic; (c) drawing the heated precursor web under tension in a substantially lateral direction to cause the web to consolidate longitudinally and thereby reduce the maximum pore size measure of the web by at least 20%, wherein the heating and drawing steps are carried out continuously by passing the precursor web, while heated, through a lateral strain mechanism; (d) obtaining a longitudinally consolidated planar web; and (e) cooling the web or permitting the web to cool.

Claim 27

Dependent Claim 36 words

The method as claim 21 wherein the drawing step is sufficient to provide the web with a mean flow pore size measure at least 20% smaller than the mean flow pore size of the precursor web.

Claim 28

Dependent Claim 28 words

The method of claim 21 wherein the drawing step is sufficient to provide the web a packing density at least 20% greater than that of the precursor web.

Claim 29

Dependent Claim 45 words

The method of claim 21 wherein after the drawing step the drawing tension is released, and wherein the cooling step is carried out prior to the release of the drawing tension and cools the web to a temperature below the softening temperature of the thermoplastic.

Claim 30

Dependent Claim 49 words

The method of claim 21 wherein at least one of said first and second layers of the nonwoven precursor web is a meltblown web having an average fiber diameter of 0.5 to 8 microns and having an elongation at break of less than 40% based on ASTM D 5035-90.

Claim 31

Dependent Claim 21 words

The method of claim 25 wherein the meltblown layer has a breaking elongation less than 30% based on ASTM D 5035-90.

Claim 32

Dependent Claim 39 words

The method of claim 21 wherein the thermoplastic is a polyolefin selected from the group consisting of polypropylene, polyethylene, and copolymers thereof, and the heating step is carried out at a temperature of between 190 to 350 degrees Fahrenheit.

Claim 33

Dependent Claim 16 words

The method of claim 27 wherein the meltblown precursor web has randomly distributed throughout fiber-fiber bonding.

Claim 34

Dependent Claim 25 words

The method of claim 21 wherein the thermoplastic is selected from polyesters, polyamides, cellulose triacetate, cellulose diacetate, poly-4-methylpentene-1, polyphenylene sulfide, liquid crystal polymers and fluoropolymers.

Claim 35

Dependent Claim 43 words

The method of claim 21 wherein at least one of said first and second layers of the precursor nonwoven web is a spun-bond web having fibers of from 7 to 50 micron average diameter and having spaced apart bonds distributed through the web.

Claim 36

Dependent Claim 32 words

The method of claim 21 wherein the precursor web is a composite comprising a meltblown layer/a cotton layer/and a meltblown layer, wherein the layers are thermally bonded together at spaced apart locations.

Claim 37

Dependent Claim 66 words

The method of claim 21 wherein the precursor web has a width of 6 to 160 inches and a thickness of 2 to 100 mils and wherein the drawn web has a width of more than 125% of the precursor web and a thickness of 2 to 150 mils and wherein the thickness ratio of the drawn web and precursor web ranges from 1:1 to 1.5:1.

Claim 38

Dependent Claim 42 words

The method of claim 21 wherein said precursor web passes into the lateral strain mechanism at a first linear velocity and exits the lateral strain mechanism at a second linear velocity, and wherein said first velocity is greater than said second velocity.

Claim 39

Dependent Claim 12 words

The method of claim 21 wherein the precursor nonwoven web is planar.

Claim 40

Dependent Claim 23 words

The method of claim 21 wherein the drawing the heated precursor web under tension causes the web to have a uniform planar strain.

Claim 41

Independent Claim 93 words

A method for treating a planar nonwoven, longitudinally extending web which includes nonelastic thermoplastic fibers, the method comprising, heating the web to a temperature between the softening temperature and the melting temperature of the thermoplastic fibers while moving the web forward in a longitudinal direction, grasping opposing side margins of the heated web and exerting a lateral strain upon the heated web while continuing to move the web forward in a longitudinal direction, whereby the web is consolidated in the longitudinal direction, and obtaining a longitudinally consolidated, planar, elastic, nonwoven, longitudinally extending web.

Claim 42

Independent Claim 93 words

A method for treating a planar nonwoven, longitudinally extending web which includes nonelastic thermoplastic fibers, the method comprising, heating the web to a temperature between the softening temperature and the melting temperature of the thermoplastic fibers while moving the web forward in a longitudinal direction, grasping opposing side margins of the heated web and exerting a lateral strain upon the heated web while continuing to move the web forward in a longitudinal direction, whereby the web is consolidated in the longitudinal direction, and obtaining a longitudinally consolidated, planar, elastic, nonwoven, longitudinally extending web.

Claim 43

Independent Claim 125 words

An apparatus for post treating a nonwoven web including nonelastic thermoplastic fibers, comprising: transport means for drawing the web through the apparatus; means for heating the transported web to a temperature between a softening temperature and a melting temperature of the thermoplastic fibers; and means for grasping opposing side margins of the heated web, and for exerting a lateral strain upon the heated web while the web is drawn through the apparatus by the transport means; wherein the web is introduced to the grasping means at a rate which is in excess of a rate of acceptance of the web by the grasping means so that the web is bunched up as the side margins of the heated web are engaged by the grasping means.

Claim 44

Independent Claim 125 words

An apparatus for post treating a nonwoven web including nonelastic thermoplastic fibers, comprising: transport means for drawing the web through the apparatus; means for heating the transported web to a temperature between a softening temperature and a melting temperature of the thermoplastic fibers; and means for grasping opposing side margins of the heated web, and for exerting a lateral strain upon the heated web while the web is drawn through the apparatus by the transport means; wherein the web is introduced to the grasping means at a rate which is in excess of a rate of acceptance of the web by the grasping means so that the web is bunched up as the side margins of the heated web are engaged by the grasping means.

Claim 45

Dependent Claim 25 words

The apparatus of claim 37 wherein the web is drawn through the apparatus in a longitudinal direction, for consolidating the web in the longitudinal direction.

Claim 46

Dependent Claim 32 words

The apparatus of claim 38 which further includes means for constraining the grasped web so that the web is subjected to a substantially uniform strain in a plane defined by the web.

Claim 47

Dependent Claim 54 words

The apparatus of claim 39 wherein the grasping means extends the width of the web by a first amount, wherein the transport means introduces the web to the grasping means in a second amount, and wherein a ratio of the first amount to the second amount lies within a range of 1:1.1 and 1:2.

Claim 48

Dependent Claim 18 words

The apparatus of claim 40 wherein the grasping means and the transport means operate continuously upon the web.

Claim 49

Dependent Claim 24 words

The apparatus of claim 37 wherein the grasping means are sprockets having peripherally disposed teeth for engaging the opposing side margins of the web.

Claim 50

Dependent Claim 23 words

The apparatus of claim 42 wherein the sprockets lie in a plane which is substantially parallel to a plane defined by the web.

Claim 51

Dependent Claim 25 words

The apparatus of claim 42 wherein the sprockets are spaced apart by a distance which is slightly less than an unstretched width of the web.

Claim 52

Dependent Claim 21 words

The apparatus of claim 42 wherein the grasping means further includes chain means for at least partially wrapping around the sprockets.

Claim 53

Dependent Claim 27 words

The apparatus of claim 45 which further includes idler sprockets for guiding the chain means relative to the sprockets and to means for driving the chain means.

Claim 54

Dependent Claim 33 words

The apparatus of claim 46 wherein the idler sprockets are located relative to the sprockets to select a degree of wrap of the chain means about the peripherally disposed teeth of the sprockets.

Claim 55

Dependent Claim 35 words

The apparatus of claim 47 wherein idler sprockets located downstream from the sprocket are spaced apart about a centerline of the apparatus at a distance which exceeds a distance separating the teeth of the sprockets.

Claim 56

Dependent Claim 19 words

The apparatus of claim 48 wherein the spacing between the idler sprockets located downstream from the sprockets is adjustable.

Claim 57

Dependent Claim 25 words

The apparatus of claim 45 which further includes a roll associated with frame portions of the apparatus, for delivering the web to the grasping means.

Claim 58

Dependent Claim 16 words

The apparatus of claim 50 wherein the transport means includes a motor for operating the roll.

Claim 59

Dependent Claim 23 words

The apparatus of claim 51 wherein the motor is variable in speed, for controlling forward movement of the web toward the grasping means.

Claim 60

Dependent Claim 26 words

The apparatus of claim 53 which further includes friction rollers located upstream from the sprockets and positioned to engage the opposing side margins of the web.

Claim 61

Dependent Claim 16 words

The apparatus of claim 53 wherein the transport means includes motors for operating the friction rollers.

Claim 62

Dependent Claim 46 words

The apparatus of claim 54 wherein the transport means includes a controller which is electrically connected to the motors for operating the friction rollers, the motor for operating the roll for delivering the web to the grasping means, and a motor for operating the chain means.

Claim 63

Dependent Claim 73 words

The apparatus of claim 55 wherein the controller operates the motors for operating the friction rollers and the motor for operating the chain means so that the chain means has a transport speed and the friction rollers have a tangential speed which is greater than the transport speed of the chain means, thereby developing a plurality of ridges and valleys extending laterally across the web as the web is delivered to the sprockets.

Claim 64

Dependent Claim 41 words

The apparatus of claim 56 wherein the controller operates the motor for operating the roll for delivering the web so that the web is delivered at a rate of forward movement which substantially equals the tangential speed of the friction rollers.

Claim 65

Dependent Claim 53 words

The apparatus of claim 57 wherein the web has a first transport speed for introduction to the grasping means and a second transport speed upon leaving the grasping means, and wherein the first transport speed has a ratio relative to the second transport speed which lies within a range of 1:1.1 to 1:2.

Claim 66

Dependent Claim 24 words

The apparatus of claim 53 wherein the friction rollers are positioned to wrap the opposing side margins of the web around the chain means.

Claim 67

Dependent Claim 50 words

The apparatus of claim 59, wherein the teeth of the sprockets engage the chain means and the opposing side margins of the web which are wrapped around the chain means, for increasing the width of the web and for laterally straining the web so that the web is longitudinally consolidated.

Claim 68

Dependent Claim 30 words

The apparatus of claim 37 wherein the heating means includes a blower for directing air through a duct having an outlet located adjacent to and extending between the grasping means.

Claim 69

Dependent Claim 34 words

The apparatus of claim 61 which further includes a hooded chamber in alignment with the outlet of the duct, for retaining heated air in contact with the web for a selected amount of time.

Claim 70

Dependent Claim 23 words

The apparatus of claim 61 which further includes a duct for directing cooled air through an outlet located downstream from the grasping means.

Claim 71

Dependent Claim 24 words

The apparatus of claim 37 wherein the grasping means are trains of grabbers having means for engaging the opposing side margins of the web.

Claim 72

Dependent Claim 13 words

The apparatus of claim 64 wherein the grabbers include a plurality of pins.

Claim 73

Dependent Claim 13 words

The apparatus of claim 64 wherein the grabbers include a plurality of changes.

Claim 74

Dependent Claim 25 words

The apparatus of claim 64 wherein the trains of grabbers are mounted in track means for causing the web to move past the heating means.

Claim 75

Dependent Claim 26 words

The apparatus of claim 67 wherein the track means diverge from one another, for laterally straining the web as it is moved past the heating means.

Claim 76

Dependent Claim 42 words

The apparatus of claim 68 wherein the grabbers of each train are spaced from one another by a distance which decreases as the train of grabbers passes the heating means, thereby reducing web velocity in accordance with longitudinal contraction of the web.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1998-08-21	1999-02-20	1999-08-22	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2002-08-21	2003-02-20	2003-08-22	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2006-08-21	2007-02-20	2007-08-22	$7700.00	Window Closed / Lapsed

Post-treatment of laminated nonwoven cellulosic fiber webs

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