Patent Document

This application claims the benefit of priority under 35 USC 119 from the following U.S. Provisional Applications: Ser. No. 60/189,231, filed Mar. 14, 2000; Ser. No. 60/189,240, filed Mar. 14, 2000; and Ser. No. 60/242,877 filed Oct. 24, 2000. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to folded fastening assemblies and method and apparatus for producing and applying the fastening assemblies. 
     Fastening assemblies that carry hooks or loops are desirable as part of infant and adult diapers, surgical gowns, and other garments and wraps. Fastening assemblies typically comprise a flexible sheet-form film or non-woven web, that has a tab for connecting to an object and a tape of fastener hook elements secured to a surface of the web, forming a laminate structure. The tab of the fastening assembly is attached to one side of an object and the fastener tape is free to engage a hook-engageable surface formed on an opposite side of the object. The fastener tape is typically made of a synthetic resin that is not stretchable, and the resulting laminate is relatively stiff, does not stretch, and does not present the desired degree of cloth-like feel. 
     Fastening assemblies are often formed by laminating the sheet form film or web with a fastener tape and forming a tab for connecting to an object. One typical application for such fastener tabs is for diaper closure systems. The diaper is generally sold with one end of the fastener tab pre-attached to one of the sides of the diaper and the other end of the fastener tab releasably attachable to the other side of the diaper for securing the diaper around a baby. 
     It is desirable to provide an economical method of forming fastening assemblies that have a tab and a fastener tape. It is also desirable to provide such assemblies having integral components that achieve desired qualities, such as elasticity, flexibility and low cost and ability to be employed in existing automated assembly systems, such as systems for mass-produced diapers. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the invention, a method of forming a fastening product is provided. The fastener product has a multiplicity of fastener elements extending from a strip-form base, the base including first and second attachment members for attachment of a substrate therebetween. The method includes continuously introducing molten resin to a gap defined adjacent a peripheral surface of a rotating mold roll, such that the resin forms part of the strip-form base of the product at the peripheral mold roll surface and fills an array of fixed cavities defined in the rotating mold roll to form portions of the fastener elements as projections extending from a first side of the sheet-form base. The method also includes introducing to the resin on the mold roll a sheet material folded about a longitudinal fold line to form first and second overlapping fold portions, the sheet material introduced under conditions selected to cause the second fold portion to become permanently bonded to resin of the base, while leaving the first fold portion free to be subsequently unfolded from the second fold portion about the fold line. The resin is solidified and stripped from the peripheral surface of the mold roll by pulling the projections from their respective cavities. 
     Variations of this aspect of the invention can include one or more of the following features. The folded material is folded about multiple fold lines separating more than two fold members. The second fold portion is bonded to the first side of the base from which the fastener elements extend. The second fold portion is bonded to a second side of the base opposite the first side from which the fastener elements extend. 
     In another aspect of the invention a method of forming a fastening assembly includes molding a continuous sheet-form base having a multiplicity of fastener elements integrally molded with and extending from a fastening section of a surface of the base lying generally in a plane. The base, as molded, has a non-planar undulation in which the base extends out of its plane to form a peak that extends along a longitudinal direction of the base with opposite major surfaces of the base remaining generally parallel. The undulation is elastically deformable to enable the base to stretch laterally upon application of a lateral tensile force to the fastener product. 
     Variations of this aspect of the invention can include one or more of the following features. The base, as molded, has multiple, parallel undulations, each undulation forming a peak. The undulations are disposed in a region adjacent the fastener elements. The undulations are molded integrally with the fastener section. The undulation is formed by a mating groove and channel of a pair of rolls defining a nip in which the base is formed. The undulation is pre-formed on a material that is introduced into a base-forming nip formed by a pair of rolls; the rolls having a mating groove and channel that accommodate the undulation. 
     Other variations can include coating the undulation with an elastomer and/or filling an area between adjacent peaks with an elastomer. The elastomer is selected from the group consisting of thermoplastic elastomers, thermoplastic polyurethanes, elastomeric copolymers containing polyethylene terephthalate PET, thermoplastic olefins, and natural or synthetic rubber. The fastener section is molded of resin selected from the group consisting of polyester, polyethylene, polypropylene, polyamide and copolymers and alloys thereof. The method includes forming a tab joined with the base, the tab extending laterally from the undulation along a lateral margin of the fastener assembly opposite a second lateral margin more nearly adjacent the fastening section, the tab comprising at least one flap for joining the fastener assembly to an article. The flap is formed of a section of the base molded integrally with and of the same resin as the portion having the undulation and the fastening section. The flap is formed by folding and permanently joining a portion of the base to another portion of the base. The portion of the base that is folded is thinner than other portions of the base. The Tab is formed by introducing a sheet material into a nip in which the base is molded, the sheet material being folded about a longitudinal fold line to form first and second overlapping fold portions and introduced under conditions selected to cause the second fold portion to become permanently bonded to resin of the base, while leaving the first fold portion free to be subsequently unfolded from the second fold portion about the fold line. The sheet material is bonded to a surface of the base opposite the first surface from which the fastener elements extend. The sheet material is bonded to the first surface of the base from which the fastener elements extend. The second fold portion is bonded to the base only along a margin area of an exposed surface of the second fold portion. Unbonded surface areas of the first and second fold portions are protected from contact with the resin by a protective tape forming a barrier to the resin. Unbonded surface areas of the first and second fold portions are protected from contact with the resin by a protective coating forming a barrier to the resin. The method includes forming dams along edges of the fastening section. The dams are higher than the fastener elements. The step of permanently joining is achieved by heat staking, adhesive or rf-welding together the portion of the base to another portion of the base. 
     In another aspect of the invention, a method of forming fastener tabs, each tab including a multiplicity of fastener elements extending from a strip-form base and first and second attachment legs for attaching the tab to a garment or substrate therebetween, is disclosed. The method includes continuously introducing molten resin to a gap defined adjacent a peripheral surface of a rotating mold roll, such that the resin forms at least a part of the strip-form base of the product at the peripheral mold roll surface and fills an array of fixed cavities defined in the rotating mold roll to form portions of the fastener elements as projections extending from a first side of the sheet-form base; while introducing a pre-formed material to the resin under conditions selected to cause a portion of the resin to become permanently bonded to the pre-formed material, the preformed material forming at least a part of the strip-form base of the product. The resin is solidified and stripped from the peripheral surface of the mold roll by pulling the projections from their respective cavities. The method further includes folding a portion of the strip-form base to form the first and second attachment legs. 
     This aspect of the invention can include any of the variation mentioned herein with respect to other aspects of the invention. 
     In another aspect, the invention is a method of forming fastener tabs, each tab including a multiplicity of fastener elements extending from a strip-form base and first and second attachment legs for attaching the tab to a garment or substrate therebetween. The method includes continuously introducing molten resin to a gap defined adjacent a peripheral surface of a rotating mold roll, such that the resin forms at least a part of the strip-form base of the product at the peripheral mold roll surface and fills an array of cavities defined in the rotating mold roll to form portions of the fastener elements as projections extending from a first side of the sheet-form base. The resin is solidified and stripped from the peripheral surface of the mold roll by pulling the projections from their respective cavities. The method further includes folding a portion of the strip-form base to form the first and second attachment legs. 
     Variations of this aspect of the invention can include any of the variations mentioned herein with respect to other aspects of the invention. 
     In another aspect of the invention, a fastening assembly is provided. The fastening assembly includes a multiplicity of fastener elements integrally molded with and extending from a first surface of a sheet-form base to form a fastening section of the fastening assembly, and a spring section integrally molded with and extending laterally from the fastening section, the spring section formed by at least one undulation of the sheet form base that allows the spring section to stretch elastically in a lateral direction upon application of lateral tension to the fastening assembly. 
     Variations of this aspect of the invention can include one or more of the following features. The undulation is coated with an elastomeric resin. The undulation is triangular. The undulation is sinusoidal. The fastening assembly further includes a tab section having a first and a second attachment leg. 
     In another aspect, the invention provides a fastener tab including a continuous, unitary strip of thermoplastic resin having first and second end regions, a multiplicity of fastener elements, each having a stem integrally molded with and extending from a surface of the unitary strip disposed in the first end region, and the second end region having two opposable leg portions formed integrally with and of the same material as the continuous strip, the two opposable leg portions positioned to be secured to oppositely directed faces of a substrate or article to support the tab in a manner that the first end may be free to enable its fastener elements to engage a mating surface. 
     Variations of this aspect of the invention can include one or more of the following features. The leg portions extend from a common hinge region. The strip of thermoplastic resin has a longitudinal profile configured to define at least one hinge region. The hinge region is defined by a localized reduction in thickness of the strip of thermoplastic resin. Portions of the strip of thermoplastic resin are folded together and permanently joined to define the two leg portions. The continuous strip of thermoplastic resin has at least two spaced apart-localized lines of reduced thickness extending longitudinally across the strip to define two hinge regions about which adjacent portions of the strip are folded to constitute the leg portions. The strip, as initially formed, has a substantially longitudinal straight profile with a first hinge region spaced from its adjacent end a first distance and a second hinge region spaced from the end a substantially greater distance, the strip having been bent back upon itself about the second hinge, the bent back portion being permanently joined to the remainder of the strip adjacent to the first hinge region, the outer portion of the strip being free to bend about the first hinge to form an attachment jaw for receiving therebetween a substrate or article to which the oppositely directed surfaces of the respective leg portions may be joined. The bent back portion is permanently joined to the remainder of the strip by adhesive. The bent back portion is permanently joined to the remainder of the strip by ultrasonic bonding. The bent back portion is permanently joined to the remainder of the strip by heat staking. 
     In another aspect the invention provides a fastener tab. The fastener tab includes a strip form, unitary body consisting essentially of a contiguous resin, the body having a first end and a second end, hooks in a first end region, and two opposable legs in a second end region spaced apart from the hooks for mounting the fastener tab to opposite sides of a substrate. 
     Variations of this aspect of the invention can include one or more of the following features. The second end region includes a first portion, a second portion, and a hinge therebetween. The second end region is folded about the hinge to overlap the first portion and the second portion. The fastener tab further includes at least one of an adhesive, an ultrasonic weld or a heat stake, joining the overlapped first and second portions. The hinge is defined by a section of decreased thickness. The second region further includes a third portion and a second hinge between the second portion and the third portion. The first portion extends generally in a plane defined by the first end region, and the second portion is folded back over the first portion. The first portion extends out of a plane defined by the first end region, and the second portion is folded back over the first portion. One of the two opposable legs comprises an integrally molded portion extending out of a plane defined by the first end region. The second end region includes a first portion extending generally in a plane defined by the first end region, a second portion folded back over the first portion, and a third portion folded back over the second portion. The second portion forms a first of the two opposable legs, and the third portion forms a second of the two opposable legs. The first and second portions are permanently joined by one of adhesive, heat staking, and ultrasonic welding. The body defines a hinge located between the first portion and the second portion. The body defines a hinge located between the second portion and the third portion. The second end region includes a first portion extending out of a plane defined by the first end region, a second portion folded back over the first portion, and a third portion extending generally in the plane defined by the first end region. The third portion forms a first of the two opposed legs, and the second portion forms a second of the two opposed legs. The first and second portions are permanently joined by one of adhesive, heat staking, and ultrasonic welding. Each of the two opposed legs has an inner facing surface including an adhesive. The adhesive includes a pressure sensitive adhesive. The body is formed of a thermoplastic synthetic resin. The resin includes polypropylene. 
     In another aspect, the invention provides a roll of fastener tabs joined side-to-side. Each fastener tab includes a strip form, unitary body consisting essentially of a contiguous resin, the body having a first end and a second end, hooks in a first end region, and two opposable legs in a second end region spaced apart from the hooks for mounting the fastener tab to opposite sides of a substrate. 
     Variations of this aspect of the invention can include one or more of the following features. The two opposable legs are stored in a flat, open position. Each of the two opposed legs has an inner facing surface including an adhesive. The strip form unitary body further includes a release liner covering the adhesive. The body of each tab has projections extending from a surface opposite the adhesive and arranged to be engaged by the adhesive of an overlapping layer of the roll, to limit inter-tab adhesion. The body of each tab has a silicone coating on a surface opposite the adhesive and arranged to be engaged by the adhesive of an overlapping layer of the roll, to limit inter-tab adhesion. 
     Other features and advantages of the invention will be apparent from the following description of embodiments, and from the claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A is a perspective view of a diaper comprising fastening assemblies. 
     FIG. 1B is a perspective view of a fastening assembly. 
     FIG. 1C is a side, cross-sectional view of the fastening assembly of FIG.  1 B. 
     FIG. 1D is an expanded side, cross-sectional view of the area  1 D of FIG.  1 C. 
     FIG. 1E is a side, cross-sectional view of the fastening assembly of FIG. 1B in compressed state. 
     FIG. 1F is a side, cross-sectional view of the fastening assembly of FIG. 11B in extended state. 
     FIG. 2A is a perspective view of a continuous web from which the fastening assembly of FIG. 1B is cut. 
     FIG. 2B is a schematic plan view of a preferred non-woven web for use in the tab of FIG.  1 B. 
     FIG. 2C is an enlarged schematic plan view of the face of the non-woven loop material shown in FIG.  2 B. 
     FIG. 3A is a side view of the apparatus forming the web of FIG.  2 A. 
     FIG. 3B is a view of the molding apparatus of FIG. 3A along line  3 B— 3 B. 
     FIG. 3C is a diagrammatic side view of the non-woven web  108  along lines  3 C— 3 C of FIG.  3 A. 
     FIG. 3D is a diagrammatic cross-sectional side view of the web  200  along lines  3 D— 3 D of FIG.  3 A. 
     FIG. 4A is a side view of another apparatus forming the web of FIG.  2 A. 
     FIG. 4B is a view of the molding apparatus of FIG. 4A along line  4 B— 4 B. 
     FIG. 4C is a diagrammatic side view of the non-woven web  108  along lines  4 C— 4 C in FIG.  4 A. 
     FIG. 4D is a diagrammatic cross-sectional side view of the web  200  along lines  4 D— 4 D in FIG.  4 A. 
     FIG. 4E is a view of the post forming apparatus of FIG. 4A along line  4 E— 4 E. 
     FIG. 5 is a side, cross-sectional view of another fastening assembly. 
     FIG. 5A is a side view of an apparatus forming the web of FIG.  5 E. 
     FIG. 5B is a view of the molding apparatus of FIG. 4A along line  4 B— 4 B. 
     FIG. 5C is a diagrammatic cross-sectional side view of the post processing apparatus  180  along lines  5 C— 5 C in FIG.  5 A. 
     FIG. 5D is a diagrammatic cross-sectional side view of the post processing apparatus  190  along lines  5 D— 5 D in FIG.  5 A. 
     FIG. 5E is a perspective view of a continuous web  300  from which the fastening assembly of FIG. 5 is cut. 
     FIG. 5F is a view of the molding apparatus of FIG. 5A along line  5 F— 5 F. 
     FIG. 6A is a perspective view of a diaper comprising a belt-type fastening assembly. 
     FIG. 6B is perspective view of a belt-type fastening assembly. 
     FIG. 6C is a perspective view of a continuous web  450  from which the belt-type fastening assembly of FIG. 6B is cut. 
     FIG. 6D is a side view of an apparatus-folding web  412  of FIG.  6 C and in situ laminating it to a fastening section. 
     FIG. 6E is a diagrammatic cross-sectional side view of the web  450  of FIG. 6C with a folded web  412 . 
     FIG. 7A is a diagrammatic cross-sectional side view of another fastening assembly. 
     FIG. 8 is a perspective view of a diaper including fastener tabs, according to the invention. 
     FIG. 9A is a perspective view of the fastener tab of FIG.  8 . 
     FIG. 9B is a side view of the fastener tab of FIG.  9 A. 
     FIG. 10 is a highly magnified view of a hook portion of the fastener tab of FIG.  9 A. 
     FIG. 11A is a side view of the fastener tab of FIG. 9A shown in an unfolded state. 
     FIG. 11B is a side view of the fastener tab of FIG. 9A shown in a partially folded state. 
     FIG. 12 is a perspective view of a continuous web of fastener tab material stored in roll form. 
     FIG. 13A is a side view of the fastener tab of FIG. 9A shown partially attached to a substrate. 
     FIG. 13B is a side view of the fastener tab of FIG. 9A shown attached to a substrate with the fastener tab in a protected position. 
     FIG. 13C is a side view of the fastener tab of FIG. 9A shown attached to a substrate and in position for use. 
     FIG. 14A is a side view of an apparatus for forming a continuous web of fastener tab material. 
     FIG. 14B is a front view of a molding/calendaring assembly of the apparatus of FIG. 14A, taken along line  14 B— 14 B. 
     FIG. 14C is a perspective view of the molding/calendaring assembly of FIG. 14B shown with a guide roll. 
     FIG. 15 is an end view of the continuous web produced by the molding/calendaring assembly of FIG.  14 B. 
     FIG. 16 is a perspective view of an alternative embodiment of a continuous web of fastener tab material. 
     FIG. 17A is a side view of an alternative embodiment of a fastener tab shown in an unfolded state. 
     FIG. 17B is a side view of the fastener tab of FIG. 17A shown in a folded state. 
     FIG. 18 is a side view of an alternative embodiment of a fastener tab. 
     FIG. 19 shows a mold roll for forming the fastener tab of FIG.  18 . 
     FIG. 20A is a side view of an additional alternative embodiment of a fastener tab shown in an unfolded state. 
     FIG. 20B is a side view of the fastener tab of FIG. 20A shown in a folded state. 
     FIG. 21 shows a mold roll and base roll for forming the fastener tab of FIG.  20 A. 
     FIG. 22A is a cross-sectional view of a tape product of side-by-side fastener tab pre-forms. 
     FIG. 22B is a cress-sectional view of the fastener tab pre-forms of FIG. 21A folded to form multiple individual fastener tab products. 
    
    
     DESCRIPTION OF EMBODIMENTS 
     Referring to FIG. 1A two fastening assemblies  100  attach the back side  91  of a diaper  90  to the front side  93  securing the diaper about a body. 
     Each fastening assembly  100 , shown in FIGS. 1B and 1C, features a fastener tape section  102 , a stretchy undulating section  104  and a tab section  108 , which, in major part, are formed in a single operation as described below. The fastener tape section  102  includes a base  103  and hook-shaped fastening elements  105  integrally molded with and extending from one surface of base  103 . The surface of the fastener tape opposite the hooks has embossing or other surface patterns for grasping by the user. Optionally, as shown in the embodiment illustrated in FIGS. 1B-1C, on the hook side of the fastener tape at the left and right edges of the fastener tape section  102  there are two raised dams  110   a ,  110   b , in this case molded integrally with base  103 . Dams  110   a ,  110   b  are slightly higher than the hook-shaped fastening elements, serving to shield the hooks from accidentally touching and potentially scratching the skin of a baby or other user. The fastening assembly has a width w of the order of ½ inch (1.3 cm) and a length 1 of the order of 4 inches (10.2 cm). The fastener tape section  102  is of width w and has length 1 1  of the order of 1 inch (2.5 cm). In one example the hooks are of CFM-29 designation, available from Velcro USA Inc. of Manchester, N.H., U.S.A. The CFM-29 hook strip has hooks of only 0.015 inch (0.38 mm) height, a base thickness t 1 of 0.003 inch (0.08 mm) and a fastener element density of the order of 1000 or more fastener elements per square inch. The height of the dams  110   a ,  110   b  in this embodiment is about 0.020 inch (0.51 mm). 
     Other fastener element shapes capable of releasable engagement are also feasible. For example, fastener elements having a mushroom or flat-topped stem shape, a palm-tree shape or any other shape for engaging a loop material are contemplated. Furthermore, fastener elements having shapes capable of releasably engaging other fastener elements of like shape are contemplated as well. 
     Stretchy section  104  extends from base  103  of the fastener tape section  102  and comprises undulations  107  formed integrally with the base. Elastomeric resin  106  fills the spaces between the undulations  107  and covers them (FIG.  1 D). The stretchy section  104  has a length 1 2  of the order of 1 inch (2.5 cm) and is elastically extensible along the longitudinal direction  120  (FIG.  1 B). The stretchy section  104  can be extended or compressed, as shown in FIGS. 1F and 1E, respectively, by at least 50% and, preferably, by at least 100%. In certain embodiments, the undulations are triangular shaped (FIG.  1 D), in others, sinusoidal (FIG.  3 D). In one example, the undulations have a height h u  of about 0.020 inch (0.51 mm) and a width w u  of about 0.025 inch (0.64 mm) in a relaxed state. 
     Adjacent to the stretchy undulating section  104  is a tab section  108 , formed in part of a base  103   a  of resin that is integral with the undulations  107  and the fastener section  102 . In the embodiment of FIGS. 1B and 1C, the tab  108  further comprises a folded web that has one arm  108   b  in situ laminated to base  103   a  and an opposed second arm  108   a . The inside surfaces of the tab arms  108   a  and  108   b  are coated with an adhesive  109  and the adhesive  109  is covered with a liner  113  which prevents the two arms from adhering to each other. To attach the fastening assembly to the diaper  90  the liner  113  is removed, the side  94  of the diaper is inserted between the two arms  108   a ,  108   b  of the tab and laminating pressure is applied. 
     The front side  93  of the diaper  90  has a hook-engageable band  80  for engaging the fastener elements  105  of the fastener tape  102 , thus attaching the back side  91  of the diaper to the front side  93  and securing the diaper to the body of a baby (FIG.  1 A). 
     The fastening assembly of FIGS. 1B and 1C is formed by cutting sections of a continuous web  200 , shown in FIG. 2A, along the indicated lines  202 . The continuous web  200  is advantageously formed by the process and apparatus illustrated in FIGS. 3A and 3B, now to be described. 
     Extruder barrel  51  melts and forces molten plastic  53  through a slot-form die  52 . The extruded plastic enters nip  56  formed between base roll  54  and mold roll  55 . Mold roll  55  contains a section with mold cavities  59  shaped to form hook-type fastener elements. Left and right of the section with the cavities  59  there are mold ridges  61   a  and  61   b  shaped to form the dams  110   a  and  110   b , respectively. Adjacent to ridge  61   b  on the surface of the mold roll  55  and the opposing surface of the base roll  54  there are cooperating rib and groove sections  60  shaped to form undulations. The extruded plastic fills the hook cavities  59 , ridges  61   a  and  61   b , the undulating section  60 , and the further base portion  103   a , all as an integral resin member of a continuous web  200  (FIG.  3 D). 
     Simultaneously with the molded plastic  53  forming the hook and undulating sections  102 , 104 , respectively, a pre-formed web  108  enters the nip  56  and forms the tab section  108 . In one embodiment, the web  108  is a non-woven material supplied by roll  40 . The web  108  passes through guide rolls  41 , 42  and turning bars  43 , 44  and is twisted by ½ turn to form an L-shaped fold (FIG.  3 C). The surface of the web forming the inside of the L-shaped fold is coated with a barrier layer  213  preventing the molded plastic from penetrating the non-woven web and fusing both sides of the folded web. The web enters the nip  56  so that one arm  108   a  of the L-shaped fold is inserted into slot  62  formed on the mold roll  55  and the other arm  108   b  overlaps partially and fuses with the molded plastic  53  forming the base  103  along the region  112  (FIG.  3 D). The so-formed continuous web  200  travels about a segment of the periphery of mold roll  55  and is guided by guide rolls  57 ,  58  to post-processing stages  67  and  68 . At post-processing stage  67  the inside surface of the L-shaped tab  108  is coated with an adhesive  109  and, optionally, a liner  113  is placed between the two arms  108   a ,  108   b . Leg  108   a  is folded flat toward Subsequently the two arms  108   a ,  108   b  are folded down by turning bars  63 , 64  and the web passes through post-processing stage  68  where the undulations are compressed and doctor blades  71  apply an elastomeric resin  106  in the spaces between the undulations  107  and coat the tips of the undulations. 
     The elastomeric resin  106  is a thermoplastic polymer selected from the group consisting of thermoplastic elastomers, thermoplastic polyurethanes, elastomeric copolymers containing polyethylene terephthalate (PET), thermoplastic olefins, and natural or synthetic rubber. In one embodiment, the elastomeric resin  106  is composed of Santoprene®, having an elongation in the range of 50% to 300% and a recovery of at least 75%. 
     The preformed web  108  may be a preformed non-woven or knitted loop material. In preferred embodiments, the non-woven loop material is a needled non-woven fabric, that has thickness of the order of 0.05 inch and basis weight of about 2 ounces or less per square yard (68 grams per square meter) (FIG.  2 B). This very thin non-woven material  108  is dimensionally-stable and has relatively free hook-engageable fibers that extend from at least one side of a continuous, tangled mat of fibers  72  that form the web (FIG.  2 C). These fibers have portions available to be engaged by loop-engageable hooks while portions of the fibers at both sides of the engageable portions are secured to the mat of fibers. In present, particularly preferred embodiments, the non-woven needled fabric comprises staple polyester yarns of between about 18 and 4 denier, preferably 6 denier. Following needling of a bat of these fibers, the product, is stretched longitudinally and transversely, to increase its area in excess of 100%, as much as 150% or more from its as-needled condition, following which fibers in the web that engage each other are bonded or adhered together, so that the web has significant tensile strength and the hook-engageable portions of the fibers are well anchored. 
     In such a fabric the individual fibers of the mat  72  follow no definite pattern as in a woven or knit product, but extend in various directions within the plane of the fabric mat. The hook-engageable fibers that extend from the non-woven product are of the same fibers that comprise the mat but extend beyond the general mass of the mat  72 , out of its plane, generally from associated knots  74 , in the form of well anchored loop trees. 
     In a particular embodiment employing needling followed by stretching, the fibers of the mat are held in their taut, straightened condition by a water-based, acrylic binder applied to the side of the mat opposite the loops to bind the mat fibers in their straight condition to stabilize the areal dimensions of the fabric, and to secure the loops at their associated knots. The binder generally ranges between 20 and 40% of the total weight of the fabric and in the presently preferred embodiments accounts for about one third of the total weight of the non-woven component. 
     A description of suitable needled and stretched, hook-engageable non-woven materials is found in U.S. Pat. No. 6,342,285 filed Sep. 3, 1997 entitled “Fastener Loop Material, Its Manufacture, and Products Incorporating the Material”, and related U.S. Pat. No. 6,329,016, filed Mar. 3, 1999 entitled “Loop Material for Touch Fastening”, the entire contents of both of which are hereby incorporated by reference. 
     For more detail about the general operation of in situ molding methods and apparatus as illustrated, e.g., in FIG. 3A, and for variations on the process, the reader is referred to U.S. Pat. No. 5,260,015 to Kennedy, et al., which discloses laminates made with loop materials. 
     The stretchable fastening assembly of FIGS. 1B,  1 C may also be formed by the method and apparatus illustrated in FIG.  4 A. Extruder barrel  51  melts and forces molten plastic  53  through a slot-form die  52 . The extruded plastic enters the nip  56  between base roll  54  and mold roll  55 . As was described above, mold roll  55  contains a section with mold cavities  59  shaped to form hook-type fastener elements and left and right of the section with the cavities  59  there are mold ridges  61   a  and  61   b  shaped to form the dams  110   a  and  110   b , respectively. Adjacent to dam  10   b  a sheet-form portion of the plastic  153  is formed (FIG.  4 D). 
     Simultaneously with the molded plastic  53  forming the hook and sheet-form sections a web  108  folded double enters the nip  56  to form the tab section  108 . The inside surfaces of the folded web are separated by a film layer  212  or tape that prevents molded plastic from penetrating through the web and fusing both sides of the folded web. In one example, layer  212  comprises Teflon® tape. The entire backside of arm  108   b  of the folded web is in situ laminated to the base  103  along region  112  as the base is formed. The molded web travels about a segment of the periphery of mold roll  55  and guided by rolls  57 ,  225  and  224  enters a nip  227  formed between rolls  228  and  226  where the section with the undulations is formed. A heated portion  230  of the outside surface of rolls  226  and  228  has triangular or sinusoidal shaped undulations  60  which soften the sheet-form section  153  of the web and molds undulations  107  in the web  200 . After the formation of the undulations the web passes through a post-processing stage  68  where the undulations are compressed and an elastomeric resin  106  is applied in the spaces between the undulations and on the undulations. 
     In another embodiment, shown in FIG. 5, the fastening assembly  100  features a fastener tape section  102 , a stretchy undulating section  104  and a tab section  108 , which is formed by folding a portion of the integrally formed base sheet  103 . The fastening assembly of FIG. 5 is formed by cutting sections of a continuous web  300 , shown in FIG. 5E, along the indicated lines  302 . 
     Referring to FIG. 5A, a method of forming the continuous web  300  includes forming a continuous molded web featuring a section with hook-shaped fastener elements  102 , dams  110   a  and  110   b  and an undulating section  104 , as was described above. Next to the undulating section the base  103  of the web  300  is extended and a section  179  with reduced thickness is formed having fold lines  183 ,  184 ,  185  (FIG.  5 B). The thickness of the molded web is reduced by inserting a ring  172  onto the mold roll  55  which reduces the thickness of the gap that establishes the thickness of this section (FIG.  5 F). The molded web travels about a segment of the periphery of mold roll  55  and guided by rolls  57  and  58  enters a post-processing stage  180  where the base  103  is folded first upward along the fold line  183  then downward along line  184  and then horizontally along line  185  (FIG.  5 C). The folding produces an inverted V-shaped fold  108  having arms  108   a  and  108   b . The post-processing stage  180  includes a first block  181  having a longitudinally extending triangular-shaped step  188  and a second block  182  having a triangular-shaped groove  186  positioned on top of the triangular-shaped step  188 . A narrow gap is formed between the groove  186  and the step  188  receiving and folding the web  300  along lines  183 ,  184 ,  185 . The folded web  300  proceeds into next stage  190  where the two arms of the fold  108   a  and  108   b  are pressed and fused together forming a tab  108  integral with the base  103 . Stage  190  includes a base block  191  supporting the web on its surface and a heated block  192  having a slit  193  receiving and pressing the arms  108   a ,  108   b  of the fold together (FIG.  5 D). The heat melts the plastic sufficiently to fuse the two arms together. The web  300  then continues into stage  68  where the undulations are compressed and an elastomeric resin is applied in the spaces between the undulations and on the undulations. 
     Referring to FIG. 6A, the back side  91  of a diaper  90  is attached to the front side  93  by a fastening assembly forming a belt  400 . Belt  400  passes through loops  92 , surrounds the diaper  90  and forms a closure  95 . Referring to FIG. 6B, the belt  400  includes a fastening section  410  and an elongated section  420 . The fastening section  410  includes hooks  105 , dams  110   a ,  10   b  and undulations  107  providing elasticity to the fastening section  410  (FIG.  6 D). The back side  411  of the fastening section  410  has embossing or other surface patterns for grasping by the user. The elongated section  420  comprises a non-woven web  412  which has a portion fused to a portion of the fastening section along region  112 . 
     The belt  400  is formed by cutting segments of web  450 , shown in FIG. 6C, along indicated lines  452 . The web  450  is formed with the method and apparatus shown in FIG. 3A or FIG.  4 A. The non-woven web  412  is folded forming multiple folds  414 , as shown diagrammatically in FIGS. 6D and 6E, and the folded web is introduced into the nip area  56  where it is laminated in situ to a portion of the molded fastening section. After the formation of the fastening section, web  450  is cut along lines  452  and folds  414  is unfolded resulting in the elongated section  450  forming the belt  400 . Other features and advantages of the invention may include one or more of the following. 
     The folded web  108  may be laminated onto the surface of the fastener tape opposite the surface from which the hook-shaped fastener elements extend (FIG.  7 A). 
     The adhesive  109  may be activated by ultrasound or ultraviolet light, in which case no liner  113  is applied. Further the tab  108  may be provided without the adhesive  109  and an adhesive layer may be applied on the surface of the diaper where the fastening assembly is attached during the diaper assembly operation. 
     Referring to FIG. 8, a fastener tab  510  is used to secure two components together, e.g., two fastener tabs  510  are shown securing a back  512  of a diaper  514  to a front  516  of the diaper. Fastener tab  510  is attached to diaper back  512  by, e.g., adhesive, and is releasably secured to diaper front  516  by engaging a hook-bearing fastener strip section  520  of tab  510  with a receiving region  518  on the front  516  of diaper  514 . Receiving region  518  includes, e.g., hook-engageable loops  519 . 
     Fastener tab  510 , shown in FIGS. 9A and 9B, is formed as a flexible, unitary strip of thermoplastic resin, e.g., polypropylene. Tab  510  includes fastener strip section  520 , a central strip section  522 , and an attachment section  524 . Sections  520 ,  522  and  524  are integrally formed in a single molding/calendaring operation, as described below. Tab  510  includes a continuous base portion  530 , and fastener strip section  520  includes a plurality of loop-engageable hooks  526  integrally molded with and extending from a surface  528  of base portion  530 . Referring to FIG. 10, hook protrusions  526  are molded in a high density array, as described below, each in the shape of a loop-engageable hook, with, e.g., a crook  527  or mushroom form (not shown). Alternatively, hooks  526  can be initially molded as pre-forms, with the crook or mushroom shapes or other loop-engageable configurations being formed in a post-forming operation, e.g., after the initial molding process. In one example, the hooks are of CFM-29 designation, as previously described. Hooks  526  can be arranged in alternate rows, the hooks facing in opposite directions, as shown in FIG. 10, or hooks  526  can face in the same direction. 
     Fastener strip section  520  terminates in a graspable tip portion  531  devoid of hooks which the user grasps to disengage tab  510  from receiving region  518  of diaper  514  by a peeling motion. Central strip section  522  is devoid of hooks and extends between fastener strip section  520  and attachment section  524  to provide a flexible, manipulatable support for fastener section  520 . Attachment section  524  includes a first leg  532  and a second leg  534  for attaching to opposite sides  555 ,  556  (FIG. 9B) of a diaper or other substrate  517 . An adhesive  548  on the inside surfaces  550 ,  552 , respectively, of legs  532 ,  534  is used to attach tab  510  to substrate  517 . 
     Referring to FIG. 11A, legs  532  and  534  are formed by folding base portion  530 . Base portion  530  in attachment section  524  includes a first portion  570 , a second portion  572 , and a third portion  574 . Between the first and second portions  570 ,  572  is a hinge  576 , and between the second and third portions  572 ,  574  is a hinge  578 . To form legs  532  and  534 , second portion  572  is folded over first portion  570  at hinge  576 , forming leg  532 , as shown in FIG.  11 B. Third section  574  is then folded over second portion  572  at hinge  578 , forming leg  534 , as shown in FIG.  9 B. First and second portions  570 ,  572  have a reduced thickness, which form recessed surfaces  580 ,  582 , respectively. First portion  570  is adhered to second portion  572  by an adhesive  584 , e.g., a rubber based pressure sensitive adhesive, applied to surface  580  or  582  or both. Alternatively, portions  570 ,  572  are adhered by heat staking, ultrasonic bonding or rf welding. 
     Referring again to FIGS. 9A and 9B, tab  510  has a base thickness, t 1 , of, e.g., about 0.004 to 0.006 inches, a width, w, of, e.g., about 0.75 to 2 inches, and an overall length, l, of, e.g., about 4 inches. The graspable tip portion  531  of fastener section  520  has a length, l 1 , of, e.g., about 0.25 inches, and the remainder of fastener section  520  has a length, l 2  , of, e.g., about 0.875 inches. Central strip section  522  has a length, l 3 , of, e.g., about 0.75 inches. First leg  532  has a length, l 4 , of, e.g., about 0.875 inches and second leg  534  has a length, l 5 , of, e.g., about 0.75 inches. 
     Referring to FIG. 12, fastener tabs  510  are initially formed as a continuous web  700  from which individual fastener tabs are separated along the indicated lines  702 . Web  700  is provided in a roll form  704  with attachment section  524  in the partially folded position of FIG.  11 B. To limit adherence of adhesive  548  to backside  710  of web  700  and thus aid in release and unrolling of web  700 , backside  710  is treated with a release coating, e.g. a fluorine or silicone based coating, in an area  711  that corresponds to adhesive  548 . In use, referring to FIGS. 13A-13C, an individual tab  510  is removed from web  700 , e.g., by cutting web  700  along line  702 , and attached to the diaper or other substrate  517  by contacting the adhesive bearing inside face  550  of leg  532  to one side  555  of the substrate while tab  510  is in the partially folded position of FIG.  11 B. Fastener strip section  520  and central strip section  522  are then folded in the direction of arrow C (FIG. 13B) until hooks  526  of fastener strip section  520  contact the opposite side  556  of substrate  517 . This folding motion of the unattached portion of tab  510  brings the adhesive bearing surface  552  of second leg  534  into contact with the opposite side  556  of substrate  517 , and hooks  526  into loose engagement with the material of substrate  517 . Alternatively, adhesive  548  is omitted, and another fastening technique, e.g., heat staking or ultrasonic or rf welding using the self-adhesive properties of the surfaces being joined, is employed to attach legs  532  and  534  to substrate  517 . 
     With attachment legs  532  and  534  attached to substrate  517 , and fastener strip section  520  and central strip section  522  folded over substrate  517 , tab  510  is in a protected position for further processing, packaging, and shipping of the diaper or other substrate. A user of the diaper or substrate unfolds fastener strip section  520  (FIG. 13C) to present hooks  526  for use in securing the diaper about a wearer, or otherwise using the substrate for its intended purpose. 
     Referring to FIGS. 14A-14C, continuous web  700  is formed by an extrusion apparatus  801  including a molding/calendaring assembly  303  and post-processing stages  805 . Assembly  803  includes an extruder barrel  800 , a slot-form die  804 , a base roll  808 , a mold roll  810 , a take-off roll  830 , and a guide roll  832 . Referring particularly to FIG. 14B, mold roll  810  includes, e.g., two sets of side-by-side tab forming formations, A and B, which produce two bands A′, B′ of tabs  510  (see FIG.  15 ). Mold roll  810  has a narrow ring  815  of increased diameter shaped to create a separation groove T (FIG. 15) between bands A′ and B′. Groove T is an integral, relatively thin, rupturable joint which permits easy separation of bands A′ and B′. Roll  810  has two sections  817 ,  817 ′ adjacent ring  815  that define mold cavities  812 ,  812 ′, respectively, shaped to form hook-type fastener elements  526 . Next to mold cavity sections  812 ,  812 ′, mold roll  810  has outer calendaring surfaces  813 ,  813 ′ including sections  814 ,  814 ′ of increased diameter that form reduced thickness sections  580 ,  582  in tab  510 . Near the center and edge of sections  814 ,  814 ′ are rings  816 ,  816 ′ and  818 ,  818 ′ on the mold roll  810 , shaped to form hinges  576 ,  578 , respectively. Base roll  808  is provided with a relatively smooth outer surface  809 , e.g., to provide a tab surface suitable to receive a release coating. Rolls  808  and  810  are spaced a given distance  820  to form base  530  of a desired thickness. 
     In use, extruder barrel  800  melts the resin and forces the molten plastic through slot-form die  804 , to form a sheet-form extrudate of molten plastic  802 . The extruded plastic  802 , while still molten, enters a nip  806  formed between base roll  808  and mold roll  810 . Due to pressure applied at the nip by rolls  808 ,  810 , molten resin is forced into hook cavities  812 , and, by filling the gap  820  between the rolls  808 ,  810 , forms base portion  530  and the various recessed and hinged portions, all as an integral, continuous, thermoplastic web. 
     As shown in FIGS. 14A and 14C, upon exiting nip  806 , the formed web travels about a segment of the periphery of mold roll  810  while it cools (mold roll  810  having provision for internal cooling) and then, with the aid of take-off roll  830 , the web disengages from the mold roll in a peeling action with the hook-form elements undergoing temporary elastic deformation as they exit from the mold cavities. Then, guided by guide roll  832 , the web enters a post-processing stage  850  where adhesive  584  is applied to one or both of surfaces  580 ,  582 . 
     The molded web then passes to a second post-processing stage  860 , where the continuous webs of fastener tab profiles A′ and B′ are separated along line T. Further processing of the symmetrical webs A′ and B′ is identical. For simplicity, further treatment of a single fastener tab profile will therefore be described. The web next passes through stage  870  where the web is folded along the relatively thin hinge line  576  which lies between sections  570 ,  572  until sections  570 ,  572  are adhered together. Alternatively, after the web separation of stage  860  and the folding of stage  870  are performed, sections  570 ,  572  are joined by heat staking, ultrasonic bonding or rf welding, employing the adhesive qualities of the thermoplastic resin of which the tabs are formed. 
     The molded, folded web then passes to post-processing stage  880  where adhesive  548  is applied to surfaces  550 ,  552 . Alternatively, stage  880  and the application of adhesive  548  are omitted, and adhesive or other fastening techniques are used after shipment of the fastener tabs  510  to the diaper manufacturer, prior to attachment to a diaper, e.g. fastener tab  510  is attached to a diaper or other article without the use of adhesive, e.g., by heat staking or ultrasonic or rf welding, using the self-adhesive properties of the surfaces being joined. The continuous web of fastening tab material is then wound into roll form  704  (FIG. 12) at post-processing stage  890  for shipment to diaper manufacturers. 
     For example, as shown in FIG. 16, a distribution of protruding formations  712  is formed on backside surface  710  of the web to reduce the area of contact between adhesive  548  and the backside surface  710  to aid in release and unrolling of the web. To form formations  712 , the outer surface  809  of base roll  808  is provided with a grained texture, not shown, suitable to form molded formations  712 . 
     Referring to FIGS. 17A and 17B, a fastener tab  510 ′ includes a first hinge line  537 ′, a second hinge line  536 ′ separating a thinned portion  540 ′ into first and second parts  542 ′ and  544 ′, respectively, and a third hinge line  538 ′. At a post-processing stage, e.g., after the molding/calendaring process, a second attachment leg  534 ′ of tab  510 ′ is formed by applying adhesive  541 ′ along surface  543 ′ of first part  542 ′ or surface  545 ′ of second part  544 ′ or both, and folding thinned portion  540 ′ at second hinge line  536 ′ to adhere first part  542 ′ to second part  544 ′. Alternatively, adhesive  541 ′ is omitted and first part  542 ′ is joined to second part  544 ′ by heat staking or ultrasonic bonding, using the self-adhesive properties of the surfaces being joined. The portion of base  530 ′ between third hinge line  538 ′ and free end  546 ′ forms a first leg  532 ′. Second leg  534 ′ is folded open by folding about first hinge line  537 ′ for further processing, storage, and shipping or folded closed about third hinge line  538 ′ for attachment to a substrate. 
     In another embodiment, shown in FIG. 18, fastener tab  610 ′ has first and second integrally formed legs  632 ′,  634 ′, produced without folding, and hinge lines  632 ′,  634 ′. Referring to FIG. 19, leg  634 ′ is molded using a mold roll  608 ′ with a leg forming mold cavity  633 ′ to create second leg  634 ′ and mold ridges  616 ′,  618 ′ which form hinge lines  636 ′,  638 ′, respectively. Leg  632 ′ is formed by the calendaring effect, using a process similar to that described above. Second leg  634 ′ opens by folding about first hinge line  636 ′ for further processing, storage, and shipping or closes by folding about second hinge line  638  for attachment to substrate. In this embodiment, second leg  634 ′ typically has a length, 1, of, e.g., about 0.25 inches. 
     Referring to FIGS. 20A and 20B, a fastener tab  710 ′ includes a first hinge line  737 ′, a second hinge line  736 ′ separating a thinned portion  740 ′ into first and second parts  742 ′ and  744 ′, respectively, and a third hinge line  738 ′. In this embodiment, thinned portion  740 ′ is molded/calendared in a partially pre-folded condition. To form the partial pre-fold, as shown in FIG. 21, a mold roll  720 ′ has a recessed portion  733 ′ and a pressure roll  708 ′ has a corresponding raised portion  731 ′ that, acting together in the above described molding/calendaring process, produce a thinned portion  740 ′ having an inverted V-shaped fold. At a post-processing stage, e.g., after the molding/calendaring process, a second attachment leg  734 ′ of the tab is formed by applying adhesive  741 ′ along surface  743 ′ of first part  742 ′ or surface  745 ′ of second part  744 ′ or both, and folding partially pre-folded thinned portion  740 ′ at second hinge line  736 ′ to adhere first part  742 ′ to second part  744 ′. Alternatively, adhesive  741 ′ is omitted and first part  742 ′ is joined to second part  744 ′ by heat staking or ultrasonic bonding, using the self-adhesive properties of the surfaces being joined. The portion  739 ′ between third hinge line  738 ′ and free end  746 ′ forms first leg  732 ′. Second leg  734 ′ is folded open by folding about first hinge line  737 ′ for further processing, storage, and shipping or folded closed about third hinge line  738 ′ for attachment to a substrate. 
     FIGS. 22A and 22B illustrate stages of the side-by-side simultaneous production of six fastener tabs. The dimensions are not to scale, and particularly, the thickness of the material has been exaggerated for ease of illustration. Referring to FIG. 22A, fastener tab pre-forms (TP 1 -TP 6 ) are initially produced as an integral tape  900 . Each tab pre-form has a graspable tip portion  902 , a fastener element bearing portion  904  and a tab attachment portion  906 . Underlying the entire width of web  900  is a backing web  908 . Tip portion  902  and fastener element bearing portion  904  are extruded and molded integrally from the same material onto web  908 . The heat and pressure of the molding operation, described below, laminates the molded tip and fastener element-bearing portions  902 ,  904  onto web  908  so that the materials form integral tape  900 . 
     In one example, each of the six tab pre-forms TP 1 -TP 6  has a tip portion  902  with a width, w t , of approximately ⅛ inch (3.2 mm), a fastener element-bearing portion  904  with a width, w f , of approximately ⅝ to ⅞ inch (15.9-22.2 mm), and a tab attachment portion  906  with a width, w a , of approximately 2 and ⅝ to 3 and ⅛ (66.7-79.4 mm). 
     Underlying web  908 , for example, is a film of polypropylene or polyethylene or a spun-bond nonwoven web of polypropylene or polyethylene or a laminate of a combination of these materials. Web  908  can also be of other materials such as an elastically stretchy nonwoven loop material that is releasably engageable by fastener element-bearing portion  904 . In one example, the thickness, t w , of web  908  is approximately 0.003-0.006 inch (0.08-0.15 mm) the molded, laminated material of the tip and fastener element-bearing portions  902 ,  904  can locally add an additional thickness of approximately 0.001 inch (0.03 mm) to the t w  dimension in those areas. 
     Tape  900  is initially slit along lines C 2  and C 4  to provide three fastener tape pre-form webs, each including a pair of fastener pre-forms across its width, i.e., pairs TP 1 -TP 2 , TP 3 -TP 4 , and TP 5 -TP 6  are formed. As the fastener pre-forms are further processed, each of the pairs are slit along lines C 1 , C 3  and C 5 , leaving individual pre-forms PT 1 -PT 6 . Each individual pre-form is folded and partially adhered to itself in a process similar to that described above with reference to FIGS. 11A and 11B. The resulting fastener tabs T 1 -T 6  are illustrated in FIG.  22 B. Again, the dimensions are not to scale and, particularly, the thickness of the base portion and folded portions is exaggerated for ease of illustration. Fastener tab products T 1 -T 6  are shown with attachment flap  910  in a partial closed position, ready for attachment to e.g., a garment or substrate, in the manner described above with reference to FIG.  9 B. Also, each continuous length of fastener tab products T 1 -T 6  can be rolled for storage with or without a layer of adhesive provided for attachment, in the manner described above with reference to FIGS. 12 and 16. 
     The method of producing the side-by-side preform tab of FIG. 22A employs the same basic principles of that described above with reference to FIG.  14 C. However, the addition of the backing web, eliminates the need to provide extruded molten material over the entire width of the forming nip. Instead, the exposed surface of the tip portion  902  and the fastener elements of the fastener element-bearing portion  904  are formed as bands of molten material introduced into the nip simultaneously with the backing material  908 . Such a technique of in-situ, laminating and molding bands or islands of material to an initially separate, second material is discussed in greater detail in co-pending U.S. application Ser. No. 09/808,395, filed Mar. 14, 2001 and entitled “Hook and Loop Fastening”, the entire contents of which is hereby incorporated by reference. 
     Other features and advantages of the invention will be realized from the disclosure and drawings, and are within the scope of the following claims.

Technology Category: 1