GARMENTS AND APPARATUS AND METHODS FOR MAKING SUCH GARMENTS
Background of the Invention
The present invention relates generally to apparatus and methods for making pre-assembled or pre-fastened garments, and more particularly to apparatus and methods for promoting a secure engagement between fastening components of prefastened garments during the making of such garments.
Garments, and more particularly disposable absorbent garments, have numerous applications including diapers, training pants, medical garments, feminine care products, and adult incontinence products. A typical disposable absorbent garment is formed as a composite structure including an absorbent assembly disposed between a liquid permeable bodyside liner and a liquid impermeable outer cover. These components can be combined with other materials and features such as elastic materials and containment structures to form a product which is specifically suited to its intended purposes. A number of such garments include fastening components which are intended to be secured together (e.g., pre-fastened) during manufacture of the garment so that the product is packaged in its fully assembled form.
For example, one such pre-fastened garment is a child's training pants, which have a central absorbent chassis and front and back side panels extending laterally out from the chassis adjacent longitudinally opposite ends thereof. Each of the front and back side panels has a fastening component thereon, such as a hook or a loop fastener. During manufacture of the training pants, the central absorbent chassis is initially formed generally flat and then folded over so that the front and back side panels face each other.
The respective fastening components of the front and back side panels are then aligned and engaged with each other to
pre-fasten the training pants in its fully assembled three- dimensional form.
However, existing techniques for making conventional garments such as the training pants described above or other pre-fastened garments which engage fastening components together during manufacture are in some respects inadequate. For example, weak engagement strength between hook and loop fasteners, partial or whole separation of the fastening components during manufacture and packaging problems resulting from poorly fastened or otherwise unfastened components are some of the shortcomings of existing prefastened garment making techniques. There is a need, therefore, for apparatus and methods which increase the engagement strength between fastening components while making a pre-fastened garment.
Summary of the Invention
In general, a method for securing engagement between fastening components of a pre-fastened garment upon initial assembly thereof comprises arranging the fastening components in at least partially opposed relationship with each other and engaging the fastening components with each other to define an engagement seam. The garment is mechanically handled to generate a shear stress at the engagement seam to thereby promote increased engagement between the fastening components at the engagement seam.
In another embodiment, a method for making a prefastened garment generally comprises arranging front and back side panels of the garment relative to each other such that respective fastening components of the front and back side panels are in at least partially opposed relationship with each other. The fastening components are then engaged with each other to define an engagement seam. The garment is then
mechanically handled to generate a shear stress at the engagement seam to promote increased engagement between the fastening components .
Apparatus for making a pre-fastened garment having a pair of fastening components adapted for fastening engagement with each other during the initial making of the garment by the apparatus generally comprises a seaming section adapted to arrange the fastening components in at least partially opposed relationship with each other and being further adapted to engage the fastening components together to define an engagement seam. A tensioning assembly of the apparatus is adapted to mechanically generate a shear stress at the engagement seam to promote increased engagement between the fastening components. A tensioning assembly for apparatus for making a prefastened garment having front and back side panels including fastening components which are engaged together to define an engagement seam of the garment generally comprises a tensioning member adapted for supporting the front and back side panels of the garment while the side panels are tensioned by the apparatus. The tensioning member has a generally flat bearing surface oriented for opposed relationship with the engagement seam upon tensioning of the front and back side panels. A disposable absorbent article generally comprises a body having first and second regions. A mechanical fastening system on the body comprises a first fastening component disposed on the body in the first region and a second fastening component disposed on the body in the second region. At least a portion of the first fastening component is a hook material and at least a portion of the second fastening component is a loop material which is stretchable from a relaxed state to an elongated state. When the second
fastening component is in an elongated state and in juxtaposition and contact with the first fastening component the loop material engages the hook material as it moves from an elongated state to a relaxed state. In another embodiment, a disposable absorbent article for personal wear generally comprises a body having first and second end regions and comprising an inner layer for contact with the wearer's skin. At least a portion of the inner layer is liquid permeable. An outer layer is in opposed relation with the inner layer and an absorbent layer is disposed between the inner layer and the outer layer. A mechanical fastening system is positioned on the body including a first fastening component disposed on the body in the first end region. At least a portion of the first fastening component is a hook material. A second fastening component is disposed on the body in the second end region, with at least a portion of the second fastening component being a loop material which is stretchable and contractible . When the second fastening component is in an elongated state and in juxtaposition and contact with the hook material it further engages the hook material as it moves from an elongated state to a contracted state.
In yet another embodiment the disposable absorbent article for personal wear comprises a body having first and second end regions and comprising an inner layer for contact with the wearer's skin. At least a portion of the inner layer is liquid permeable. An outer layer is in opposed relation with the inner layer and an absorbent layer is disposed between the inner layer and the outer layer. A mechanical fastening system is positioned on the body, including a first fastening component disposed on the body in the first end region with at least a portion of the first fastening component is a hook material . A second fastening
component is disposed on the body in the second end region with at least a portion of the second fastening component being a loop material which is contractible upon the application of heat. When the second fastening component is in juxtaposition and contact with the first fastening component and then heated the second fastening component further engages the hook material as it retracts.
Definitions Within the context of this specification, each term or phrase below will include the following meaning or meanings.
"Bonded" refers to the joining, adhering, connecting, attaching, or the like, of two elements. Two elements will be considered to be bonded together when they are bonded directly to one another or indirectly to one another, such as when each is directly bonded to intermediate elements.
"Comprising" is inclusive or open-ended and does not exclude additional, unrecited elements or method steps.
"Connected" refers to the joining, adhering, bonding, attaching, or the like, of two elements. Two elements will be considered to be connected together when they are connected directly to one another or indirectly to one another, such as when each is directly connected to intermediate elements.
"Disposable" refers to articles which are designed to be discarded after a limited use rather than being laundered or otherwise restored for reuse.
"Disposed, " "disposed on, " and variations thereof are intended to mean that one element can be integral with another element, or that one element can be a separate structure bonded to or placed with or placed near another element .
"Elastic," "elasticized" and "elasticity" mean that property of a material or composite by virtue of which it
tends to recover its original size and shape after removal of a force causing a deformation.
"Elastomeric" refers to a material or composite which can be elongated by at least 25 percent of its relaxed length and which will recover, upon release of the applied force, at least 10 percent of its elongation. It is generally preferred that the elastomeric material or composite be capable of being elongated by at least 100 percent, more preferably by at least 300 percent, of its relaxed length and recover, upon release of an applied force, at least 50 percent of its elongation.
"Fabrics" is used to refer to all of the woven, knitted and nonwoven fibrous webs.
"Flexible" refers to materials which are compliant and which will readily conform to the general shape and contours of the wearer's body.
"Force" includes a physical influence exerted by one body on another which produces acceleration of bodies that are free to move and deformation of bodies that are not free to move. Force is expressed in grams per unit area.
"Graphic" refers to any design, pattern, or the like that is visible on an absorbent article.
"Hydrophilic" describes fibers or the surfaces of fibers which are wetted by the aqueous liquids in contact with the fibers. The degree of wetting of the materials can, in turn, be described in terms of the contact angles and the surface tensions of the liquids and materials involved. Equipment and techniques suitable for measuring the wettability of particular fiber materials or blends of fiber materials can be provided by a Cahn SFA-222 Surface Force Analyzer System, or a substantially equivalent system. When measured with this system, fibers having contact angles less than 90° are designated "wettable" or hydrophilic, while fibers having
contact angles greater than 90° are designated "nonwettable" or hydrophobic .
"Integral" is used to refer to various portions of a single unitary element rather than separate structures bonded to or placed with or placed near one another.
"Inward" and "outward" refer to positions relative to the center of an absorbent article, and particularly transversely and/or longitudinally closer to or away from the longitudinal and transverse center of the absorbent article. "Layer" when used in the singular can have the dual meaning of a single element or a plurality of elements.
"Liquid impermeable", when used in describing a layer or multi-layer laminate, means that a liquid, such as urine, will not pass through the layer or laminate, under ordinary use conditions, in a direction generally perpendicular to the plane of the layer or laminate at the point of liquid contact. Liquid, or urine, may spread or be transported parallel to the plane of the liquid impermeable layer or laminate, but this is not considered to be within the meaning of "liquid impermeable" when used herein.
"Longitudinal" and "transverse" have their customary meaning. The longitudinal axis lies in the plane of the garment and is generally parallel to a vertical plane that bisects a standing wearer into left and right body halves when the article is worn. The transverse axis lies in the plane of the article generally perpendicular to the longitudinal axis. The garment as illustrated is longe-r in the longitudinal direction than in the transverse direction.
"Member" when used in the singular can have the dual meaning of a single element or a plurality of elements.
"Nonwoven" and "nonwoven web" refer to materials and webs of material which are formed without the aid of a textile weaving or knitting process.
"Operatively joined," with reference to the attachment of an elastic member to another element, means that the elastic member when attached to or connected to the element, or treated with heat or chemicals, by stretching, or the like, gives the element elastic properties; and with reference to the attachment of a non-elastic member to another element, means that the member and element can be attached in any suitable manner that permits or allows them to perform the intended or described function of the joinder. The joining, attaching, connecting or the like can be either directly, such as joining either member directly to an element, or can be indirectly by means of another member disposed between the first member and the first element. "Outer cover graphic" refers to a graphic that is directly visible upon inspection of the exterior surface of a garment, and for a refastenable garment is in reference to inspection of the exterior surface of the garment when the fastening system is engaged as it would be during use.
"Permanently bonded" refers to the joining, adhering, connecting, attaching, or the like, of two elements of an absorbent garment such that the elements tend to be and remain bonded during normal use conditions of the absorbent garment .
"Refastenable" refers to the property of two elements being capable of releasable attachment, separation, and subsequent releasable reattachment without substantial permanent deformation or rupture.
"Releasably attached, " "releasably engaged" and variations thereof refer to two elements being connected or connectable such that the elements tend to remain connected absent a separation force applied to one or both of the elements, and the elements being capable of separation without substantial permanent deformation or rupture. The
required separation force is typically beyond that encountered while wearing the absorbent garment .
"Rupture" means the breaking or tearing apart of a material; in tensile testing, the term refers to the total separation of a material into two parts either all at once or in stages, or the development of a hole in some materials.
"Stretch bonded" refers to an elastic member being bonded to another member while the elastic member is extended at least about 25 percent of its relaxed length. Desirably, the term "stretch bonded" refers to the situation wherein the elastic member is extended at least about 100 percent, and more desirably at least about 300 percent, of its relaxed length when it is bonded to the other member.
"Stretch bonded laminate" refers to a composite material having at least two layers in which one layer is a gatherable layer and the other layer is an elastic layer. The layers are joined together when the elastic layer is in an extended condition so that upon relaxing the layers, the gatherable layer is gathered. "Surface" includes any layer, film, woven, nonwoven, laminate, composite, or the like, whether pervious or impervious to air, gas, and/or liquids.
"Tension" includes a uniaxial force tending to cause the extension of a body or the balancing force within that body resisting the extension.
"Thermoplastic" describes a material that softens when exposed to heat and which substantially returns to a nonsoftened condition when cooled to room temperature.
These terms may be defined with additional language in the remaining portions of the specification.
Brief Description of the Drawings
Fig. 1 is a side elevation of a child's training pants with a fastening system of the training pants shown engaged on one side of the training pants and disconnected on the other side of the training pants;
Fig. 2 is a bottom plan view of the training pants of Fig. 1 in an unfastened, stretched and laid flat condition to show the surface of the training pants which faces away from the wearer; Fig. 3 is a top plan view of the training pants it its unfastened, stretched and laid flat condition to show the surface of the training pants which faces the wearer when the training pant is worn, with portions of the training pants being cut away to reveal underlying features; Fig. 4 is a schematic of an assembly section of apparatus for making garments such as training pants;
Fig. 5 is a schematic side elevation of a folding section of the apparatus for making garments such as training pants; Fig. 6 is a schematic side elevation of a seaming section of the apparatus for making garments such as training pants;
Fig. 7 is a schematic of a portion of a continuously moving assemblage at one location along the assembly section of Fig. 4;
Fig. 8 is an enlarged side elevation of the folding section of Figure 5;
Fig. 9 is a top plan view of a portion of the folding section of Figure 5; Fig. 10 is an enlarged section view of a portion of a training pant at a location within the folding section of Fig. 2;
Fig. 11 is an enlarged side elevation of an upstream portion of the seaming section of Fig. 6;
Fig. 12 is an enlarged side elevation of a downstream portion of the seaming section of Fig. 6; Fig. 13 is a top plan view of a lower portion of the seaming section of Fig. 6;
Fig. 14 is a partial section taken in the plane of line 14-14 of Fig. 11;
Fig. 15 is a partial section taken in the plane of line 15-15 of Fig. 11;
Fig. 16 is a partial section taken in the plane of line 16-16 of Fig. 11;
Fig. 17 is a partial section taken in the plane of line 17-17 of Fig. 11; Fig. 18 is a partial section taken in the plane of line 18-18 of Fig. 11;
Fig. 19 is a partial section taken in the plane of line 19-19 of Fig. 12;
Fig. 20 is a partial section taken in the plane of line 20-20 Of Fig. 12;
Fig. 21 is a partial section taken in the plane of line 21-21 Of Fig. 12;
Fig. 22 is a partial section of a second embodiment of a seaming section of apparatus for making garments such as training pants, the section being taken at a location corresponding to the section shown in Fig. 21;
Fig. 23 is a schematic side elevation of a tucking station of apparatus for making garments such as training pants; Fig. 24 is a fragmented section taken in the plane of line 24-24 of Fig. 23;
Fig. 25 is a side elevation of another embodiment of a child's training pants;
Fig. 26 is a top plan view of the training pants of Fig. 25 in its unfastened, stretched and laid flat condition to show the surface of the training pants which faces the wearer, with portions of the training pants being cut away to reveal underlying features;
Fig. 27 schematically illustrates a flow diagram of another method for manufacturing training pants according to the present invention; and
Fig. 28 illustrates a pair of training pants of the present invention at three stages during manufacture according the method illustrated schematically in Fig. 27.
Detailed Description of the Drawings
The methods and apparatus of the present invention can be used to make a variety of garments. Examples of such garments include disposable absorbent articles such as diapers, training pants, feminine hygiene products, incontinence products, medical garments, other personal care or health care garments, swim pants, athletic clothing, pants and shorts, and the like. For ease of explanation, the methods and apparatus of the present invention are hereafter described in connection with making pre-fastened child's training pants, generally indicated as 20 in Fig. 1. In particular, the methods and apparatus will be described in terms of those for making pre-fastened disposable training pants as described in U.S. Patent Application Serial Number 09/444,083 titled "Absorbent Articles With Refastenable Side Seams" and filed November 22, 1999 (corresponding to PCT application WO 00/37009 published June 29, 2000) by A. L. Fletcher et al . , the disclosure of which is incorporated herein by reference. Training pants 20 can also be constructed using the methods and apparatus disclosed in U.S. Patent 4,940,464 issued July 10,1990 to Van Gompel et al . ;
and U.S. Patent 5,766,389 issued June 16, 1998 to Brandon et al . ; the disclosures of which are also incorporated herein by reference.
With reference now to the drawings, and in particular to Fig. 1, the training pants 20 are illustrated in a partially fastened condition and comprise an absorbent chassis 32 and a fastening system 80. The absorbent chassis 32 has a front waist region 22, a back waist region 24, a crotch region 26 interconnecting the front and back waist regions, an inner surface 28 which is configured to contact the wearer, and an outer surface 30 opposite the inner surface and configured to contact the wearer's clothing. With additional reference to Figs. 2 and 3, the absorbent chassis 32 also has a pair of laterally opposite side edges 36 and a pair of longitudinally opposite waist edges, respectively designated front waist edge 38 and back waist edge 39. The front waist region 22 is contiguous with the front waist edge 38, and the back waist region 24 is contiguous with the back waist edge 39. The illustrated absorbent chassis 32 comprises a composite structure 33 (Fig. 3) , which when laid flat can be rectangular or any other desired shape, and has a pair of laterally opposite front side panels 34 and a pair of laterally opposite back side panels 134 extending outward therefrom. The composite structure 33 and side panels 34 and 134 may comprise two or more separate elements, as shown in Fig. 1, or be integrally formed. Integrally formed side panels 34, 134 and composite structure 33 would comprise at least some common materials, such as the bodyside liner, flap composite, outer cover, other materials and/or combinations thereof, and/or could define a one-piece elastic, stretchable, or nonstretchable pants. The illustrated composite structure 33 comprises an outer cover 40, a bodyside liner 42 (Figs. 1 and 3) which is connected to the
outer cover in a superposed relation, an absorbent assembly 44 (Fig. 3) which is located between the outer cover and the bodyside liner, and a pair of containment flaps 46 (Fig. 3) . The illustrated composite structure 33 has opposite ends 45 which form portions of the front and back waist edges 38 and 39, and opposite side edges 47 which form portions of the side edges 36 of the absorbent chassis 32 (Figs. 2 and 3) . For reference, arrows 48 and 49 depict the orientation of the longitudinal axis and the transverse or lateral axis, respectively, of the training pants 20.
With the training pants 20 in the fastened position as partially illustrated in Fig. 1, the front and back side panels 34, 134 are secured together to define a three- dimensional pants configuration having a waist opening 50 and a pair of leg openings 52. The front waist region 22 comprises the portion of the training pants 20 which, when worn, is positioned on the front of the wearer while the back waist region 24 comprises the portion of the training pants which, when worn, is positioned on the back of the wearer. The crotch region 26 of the training pants 20 comprises the portion of the training pants 20 which, when worn, is positioned between the legs of the wearer and covers the lower torso of the wearer. The front and back side panels 34 and 134 comprise the portions of the training pants 20 which, when worn, are positioned on the hips of the wearer. The waist edges 38 and 39 of the absorbent chassis 32 are configured to encircle the waist of the wearer when worn and together define the waist opening 50 (Fig. 1) . Portions of the side edges 36 in the crotch region 26 generally define the leg openings 52.
The front waist region 22 of the absorbent chassis 32 generally includes the transversely opposed front side panels 34 and a front center panel 35 (Figures 2 and 3) positioned
between and interconnecting the side panels. The back waist region 24 of the absorbent chassis 32 generally includes the transversely opposed back side panels 134 and a back center panel 135 (Figures 2 and 3) positioned between and interconnecting the side panels. The waist edges 38 and 39 of the absorbent chassis 32 are configured to encircle the waist of the wearer when worn and provide the waist opening 50 which defines a waist perimeter dimension. Portions of the transversely opposed side edges 36 in the crotch region 26 generally define the leg openings 52. The waist regions 22 and 24 jointly define a waistband 75 (Fig. 1) that peripherally surrounds the waist opening 50 of the pants 20. The waist regions 22 and 24 also jointly define a hip section 77 (Fig. 1) that encircles the pant 20 and is disposed between the waistband 75 and the leg openings 52.
The absorbent chassis 32 is configured to contain and/or absorb any exudates discharged from the wearer. For example, the absorbent chassis 32 desirably although not necessarily comprises the pair of containment flaps 46 which are configured to provide a barrier to the transverse flow of body exudates. A flap elastic member 53 (Fig. 3) can be operatively joined with each containment flap 46 in any suitable manner as is well known in the art. The elasticized containment flaps 46 define an unattached edge which assumes an upright configuration in at least the crotch region 26 of the training pants 20 to form a seal against the wearer's body. The containment flaps 46 can be located along the side edges 36 of the absorbent chassis 32, and can extend longitudinally along the entire length of the absorbent chassis or may only extend partially along the length of the absorbent chassis. Suitable constructions and arrangements for the containment flaps 46 are generally well known to those skilled in the art and are described in U.S. Patent
4,704,116 issued November 3, 1987 to Enloe, which is incorporated herein by reference.
To further enhance containment and/or absorption of body exudates, the training pants 20 desirably although not necessarily include a front waist elastic member 54, a rear waist elastic member 56, and leg elastic members 58, as are known to those skilled in the art (Fig. 3) . The waist elastic members 54 and 56 can be operatively joined to the outer cover 40 and/or the bodyside liner 42 along the opposite waist edges 38 and 39, and can extend over part or all of the waist edges. The leg elastic members 58 can be operatively joined to the outer cover 40 and/or the bodyside liner 42 along the opposite side edges 36 and positioned in the crotch region 26 of the training pants 20. The leg elastic members 58 can be longitudinally aligned along each side edge 47 of the composite structure 33. Each leg elastic member 58 has a front terminal point 63 and a back terminal point 65, which represent the longitudinal ends of the elastic gathering caused by the leg elastic members. The front terminal points 63 can be located adjacent the longitudinally innermost parts of the front side panels 34, and the back terminal points 65 can be located adjacent the longitudinally innermost parts of the back side panels 134.
The flap elastic members 53, the waist elastic members 54 and 56, and the leg elastic members 58 can be formed of any suitable elastic material. As is well known to those skilled in the art, suitable elastic materials include sheets, strands or ribbons of natural rubber, synthetic rubber, or thermoplastic elastomeric polymers. The elastic materials can be stretched and adhered to a substrate, adhered to a gathered substrate, or adhered to a substrate and then elasticized or shrunk, for example with the application of heat, such that elastic constrictive forces
are imparted to the substrate. In one particular embodiment, for example, the leg elastic members 58 comprise a plurality of dry-spun coalesced multifilament spandex elastomeric threads sold under the trade name LYCRA and available from E. I. Du Pont de Nemours and Company, Wilmington, Delaware, U.S.A.
In particular embodiments, the waist elastic members 54 and 56 can be formed of retractive materials. For example, the waist elastic members 54 and 56 can be formed of an elastomeric material that is adapted to retract upon activation by a source of heat such as disclosed in U. S. Patent No. 4,640,726.
The outer cover 40 desirably comprises a material which is substantially liquid impermeable, and can be elastic, stretchable or nonstretchable. The outer cover 40 can be a single layer of liquid impermeable material, but desirably comprises a multi-layered laminate structure in which at least one of the layers is liquid impermeable. For instance, the outer cover 40 can include a liquid permeable outer layer and a liquid impermeable inner layer that are suitably joined together by a laminate adhesive, ultrasonic bonds, thermal bonds, or the like. Suitable laminate adhesives, which can be applied continuously or intermittently as beads, a spray, parallel swirls, or the like, can be obtained from Findley Adhesives, Inc., of Wauwatosa, Wisconsin, U.S.A., or from
National Starch and Chemical Company, Bridgewater, New Jersey U.S.A. The liquid permeable outer layer can be any suitable material and desirably one that provides a generally clothlike texture. One example of such a material is a 20 gsm (grams per square meter) spunbond polypropylene nonwoven web.
The outer layer may also be made of those materials of which the liquid permeable bodyside liner 42 is made. While it is . not a necessity for the outer layer to be liquid permeable,
it is desired that it provides a relatively cloth-like texture to the wearer.
The inner layer of the outer cover 40 can be both liquid and vapor impermeable, or can be liquid impermeable and vapor permeable. The inner layer can be manufactured from a thin plastic film, although other flexible liquid impermeable materials may also be used. The inner layer, or the liquid impermeable outer cover 40 when a single layer, prevents waste material from wetting articles, such as bedsheets and clothing, as well as the wearer and caregiver. A suitable liquid impermeable film for use as a liquid impermeable inner layer, or a single layer liquid impermeable outer cover 40, is a 0.02 millimeter polyethylene film commercially available from Pliant Corporation of Schaumberg, Illinois, U.S.A. If the outer cover 40 is a single layer of material, it can be embossed and/or matte finished to provide a more cloth-like appearance. As earlier mentioned, the liquid impermeable material can permit vapors to escape from the interior of the disposable absorbent article, while still preventing liquids from passing through the outer cover 40. A suitable "breathable" material is composed of a microporous polymer film or a nonwoven fabric that has been coated or otherwise treated to impart a desired level of liquid impermeability. A suitable microporous film is a PMP-1 film material commercially available from Mitsui Toatsu Chemicals, Inc., Tokyo, Japan, or an XKO-8044 polyolefin film commercially available from 3M Company, Minneapolis, Minnesota U.S.A.
As shown in Figs. 1 and 2, the training pants 20 and in particular the outer cover 40 desirably comprises one or more appearance-related components. Examples of appearance-related components include, but are not limited to, graphics; highlighting or emphasizing leg and waist openings in order
to make product shaping more evident or visible to the user; highlighting or emphasizing areas of the product to simulate functional components such as elastic leg bands, elastic waistbands, simulated "fly openings" for boys, ruffles for girls; highlighting areas of the product to change the appearance of the size of the product; registering wetness indicators, temperature indicators, and the like in the product; registering a back label, or a front label, in the product; and registering written instructions at a desired location in the product.
The illustrated pair of training pants 20 is designed for use by young girls and includes a registered outer cover graphic 60 (Fig. 2) . In this design, the registered graphic
60 includes a primary pictorial image 61, simulated waist ruffles 62, and simulated leg ruffles 64. The primary pictorial image 61 includes a rainbow, sun, clouds, animal characters, wagon and balloons. Any suitable design can be utilized for a training pants intended for use by young girls, so as to be aesthetically and/or functionally pleasing to them and the caregiver. The appearance-related components are desirably positioned on the training pants 20 at selected locations, which can be carried out using the methods disclosed in U.S. Patent No. 5,766,389 issued June 16, 1998 to Brandon et al . , the entire disclosure of which is incorporated herein by reference. The primary pictorial image
61 is desirably positioned in the front waist region 22 along the longitudinal center line of the training pants 20.
The liquid permeable bodyside liner 42 is illustrated as overlying the outer cover 40 and absorbent assembly 44, and may but need not have the same dimensions as the outer cover 40. The bodyside liner 42 is desirably compliant, soft feeling, and non-irritating to the child's skin. Further, the bodyside liner 42 can be less hydrophilic than the absorbent
assembly 44, to present a relatively dry surface to the wearer and permit liquid to readily penetrate through its thickness. Alternatively, the bodyside liner 42 can be more hydrophilic or can have essentially the same affinity for moisture as the absorbent assembly 44 to present a relatively wet surface to the wearer to increase the sensation of' being wet. This wet sensation can be useful as a training aid. The hydrophilic/hydrophobic properties can be varied across the length, width and depth of the bodyside liner 42 and absorbent assembly 44 to achieve the desired wetness sensation or leakage performance.
The bodyside liner 42 can be manufactured from a wide selection of web materials, such as synthetic fibers (for example, polyester or polypropylene fibers) , natural fibers (for example, wood or cotton fibers) , a combination of natural and synthetic fibers, porous foams, reticulated foams, apertured plastic films, or the like. Various woven and nonwoven fabrics can be used for the bodyside liner 42. For example, the bodyside liner can be composed of a meltblown or spunbonded web of polyolefin fibers. The bodyside liner can also be a bonded-carded web composed of natural and/or synthetic fibers. The bodyside liner can be composed of a substantially hydrophobic material, and the hydrophobic material can, optionally, be treated with a surfactant or otherwise processed to impart a desired level of wettability and hydrophilicity. For example, the material can be surface treated with about 0.45 weight percent of a surfactant mixture comprising Ahcovel N-62 from Hodgson Textile Chemicals of Mount Holly, North Carolina, U.S.A. and Glucopan 220UP from Henkel Corporation of Ambler,
Pennsylvania in an active ratio of 3:1. The surfactant can be applied by any conventional means, such as spraying, printing, brush coating or the like. The surfactant can be
applied to the entire bodyside liner 42 or can be selectively applied to particular sections of the bodyside liner, such as the medial section along the longitudinal center line. A suitable liquid permeable bodyside liner 42 is a nonwoven bicomponent web having a basis weight of about 27 gsm. The nonwoven bicomponent can be a spunbond bicomponent web, or a bonded carded bicomponent web. Suitable bicomponent staple fibers include a polyethylene/polypropylene bicomponent fiber available from CHISSO Corporation, Osaka, Japan. In this particular bicomponent fiber, the polypropylene forms the core and the polyethylene forms the sheath of the fiber. Other fiber orientations are possible, such as multi-lobe, side-by-side, end-to-end, or the like. The outer cover 40, bodyside liner 42 and other materials used to construct the pants can comprise elastomeric or nonelastomeric materials.
The absorbent assembly 44 (Fig. 3) is positioned between the outer cover 40 and the bodyside liner 42, which can be joined together by any suitable means such as adhesives, ultrasonic bonds, thermal bonds, or the like. The absorbent assembly 44 can be any structure which is generally compressible, conformable, non-irritating to the child's skin, and capable of absorbing and retaining liquids and certain body wastes, and may be manufactured in a wide variety of sizes and shapes, and from a wide variety of liquid absorbent materials commonly used in the art. For example, the absorbent assembly 44 can suitably comprise a matrix of hydrophilic fibers, such as a web of cellulosic fluff, mixed with particles of a high-absorbency material commonly known as superabsorbent material. In a particular embodiment, the absorbent assembly 44 comprises a matrix of cellulosic fluff, such as wood pulp fluff, and superabsorbent hydrogel-forming particles. The wood pulp fluff can be
exchanged with synthetic, polymeric, meltblown fibers or short cut homofil bicomponent synthetic fibers and natural fibers. The superabsorbent particles can be substantially homogeneously mixed with the hydrophilic fibers or can be nonuniformly mixed. The fluff and superabsorbent particles can also be selectively placed into desired zones of the absorbent assembly 44 to better contain and absorb body exudates. The concentration of the superabsorbent particles can also vary through the thickness of the absorbent assembly 44. Alternatively, the absorbent assembly 44 can comprise a laminate of fibrous webs and superabsorbent material or other suitable means of maintaining a superabsorbent material in a localized area.
Suitable superabsorbent materials can be selected from natural, synthetic, and modified natural polymers and materials. The superabsorbent materials can be inorganic materials, such as silica gels, or organic compounds, such as crosslinked polymers, for example, sodium neutralized polyacrylic acid. Suitable superabsorbent materials are available from various commercial vendors, such as Dow
Chemical Company located in Midland, Michigan, U.S.A., and Stockhausen GmbH & Co. KG, D-47805 Krefeld, Federal Republic of Germany. Typically, a superabsorbent material is capable of absorbing at least about 15 times its weight in water, and desirably is capable of absorbing more than about 25 times its weight in water.
In one embodiment, the absorbent assembly 44 comprises a blend of wood pulp fluff and superabsorbent material. One preferred type of pulp is identified with the trade designation CR1654, available from U.S. Alliance,
Childersburg, Alabama, U.S.A., and is a bleached, highly absorbent sulfate wood pulp containing primarily soft wood fibers and about 16 percent hardwood fibers. As a general
rule, the superabsorbent material is present in the absorbent assembly 44 in an amount of from 0 to about 90 percent weight based on total weight of the absorbent assembly. The absorbent assembly 44 suitably has a density within the range of about 0.10 to about 0.35 grams per cubic centimeter. The absorbent assembly 44 may or may not be wrapped or encompassed by a suitable tissue wrap that may help maintain the integrity and/or shape of the absorbent assembly.
The absorbent chassis 32 can also incorporate other materials designed primarily to receive, temporarily store, and/or transport liquid along the mutually facing surface with absorbent assembly 44, thereby maximizing the absorbent capacity of the absorbent assembly. One suitable material is referred to as a surge layer (not shown) and comprises a material having a basis weight of about 50 to about 120 grams per square meter, and comprising a through-air-bonded-carded web of a homogenous blend of 60 percent 3 denier type T-256 bicomponent fiber comprising a polyester core/polyethylene sheath and 40 percent 6 denier type T-295 polyester fiber, both commercially available from Kosa Corporation of Salisbury, North Carolina, U.S.A.
As noted previously, the illustrated training pants 20 have front and back side panels 34 and 134 disposed on each side of the absorbent chassis 32. The front side panels 34 can be permanently bonded along seams 66 to the composite structure 33 of the absorbent chassis 32 in the respective front and back waist regions 22 and 24. More particularly, as seen best in Figs. 2 and 3, the front side panels 34 can be permanently bonded to and extend transversely outward beyond the side edges 47 of the composite structure 33 in the front waist region 22, and the back side panels 134 can be permanently bonded to and extend transversely outward beyond the side edges of the composite structure in the back waist
region 24. The side panels 34 and 134 may be bonded to the composite structure 33 using attachment means known to those skilled in the art such as adhesive, thermal or ultrasonic bonding. Alternatively, the side panels 34 and 134 can be formed as an integral portion of a component of the composite structure 33. For example, the side panels can comprise a generally wider portion of the outer cover 40, the bodyside liner 42, and/or another component of the absorbent chassis 32. The front and back side panels 34 and 134 can be permanently bonded together or be releasably engaged with one another as illustrated by the fastening system 80.
The illustrated side panels 34 and 134 each have an outer edge 68 spaced laterally from the seam 66, a leg end edge 70 disposed toward the longitudinal center of the training pants 20, and a waist end edge 72 disposed toward a longitudinal end of the training pants. The leg end edge 70 and waist end edge 72 extend from the side edges 47 of the composite structure 33 to the outer edges 68. The leg end edges 70 of the side panels 34 and 134 form part of the side edges 36 of the absorbent chassis 32. In the back waist region 24, the leg end edges 70 are desirably although not necessarily curved and/or angled relative to the transverse axis 49 to provide greater coverage toward the back of the pants 20 as compared to the front of the pants. The waist end edges 72 are desirably parallel to the transverse axis 49.
The waist end edges 72 of the front side panels 34 form part of the front waist edge 38 of the absorbent chassis 32, and the waist end edges 72 of the back side panels 134 form part of the back waist edge 39 of the absorbent chassis. In particular embodiments for improved fit and appearance, the side panels 34, 134 desirably have an average length measured parallel to the longitudinal axis 48 which is about 15 percent or greater, and particularly about 25
percent or greater, of the overall length of the pants, also measured parallel to the longitudinal axis 48. For example, in training pants 20 having an overall length of about 54 centimeters, the side panels 34, 134 desirably have an average length of about 10 centimeters or greater, such as about 15 centimeters. While each of the side panels 34, 134 extends from the waist opening 50 to one of the leg openings 52, the illustrated back side panels 134 have a continually decreasing length dimension moving from the attachment line 66 to the outer edge 68, as is best shown in Figs. 2 and 3. Each of the side panels 34 and 134 can include one or more individual, distinct pieces of material. In particular embodiments, for example, each side panel 34, 134 can include first and second side panel portions that are joined at a seam, or can include a single piece of material which is folded over upon itself (not shown) . The side panels 34, 134 desirably although not necessarily comprise an elastic material capable of stretching in a direction generally parallel to the transverse axis 49 of the training pants 20. Solely by way of illustration, suitable elastic side panels
34 and 134 can be stretchable from about 150 percent to about 450 percent. This means that a panel having a relaxed length of 10 millimeters (mm) when stretched 5 mm would have been stretched 150 percent of its original length. Elastic materials if provided over the entire front and/or back region of pant 20 could fit well with lower stretch, for example from about 150 percent to about 250 percent. In embodiments where the entire front and/or back region panel is not stretchable, higher levels of stretch, for example, about 250 percent to about 450 percent may be preferred.
Suitable elastic materials, as well as one process of incorporating elastic side panels into training pants, are described in the following U.S. Patents: 4,940,464 issued
July 10, 1990 to Van Gompel et al . ; 5,224,405 issued July 6, 1993 to Pohjola; 5,104,116 issued April 14, 1992 to Pohjola; and 5,046,272 issued September 10, 1991 to Vogt et al . ; all of which are incorporated herein by reference. In particular embodiments, the elastic material comprises a stretch-thermal laminate (STL) , a neck-bonded laminate (NBL) , a reversibly necked laminate, or a stretch-bonded laminate (SBL) material. Methods of making such materials are well known to those skilled in the art and described in U.S. Patent 4,663,220 issued May 5, 1987 to Wisneski et al . ; U.S. Patent 5,226,992 issued July 13, 1993 to Morman; and European Patent Application No. EP 0 217 032 published on April 8, 1987 in the names of Taylor et al . ; all of which are incorporated herein by reference. Alternatively, the side panel material may comprise other woven or nonwoven materials, such as those described above as being suitable for the outer cover 40 or bodyside liner 42; mechanically pre-strained composites; or stretchable but inelastic materials.
The illustrated training pants 20 includes the fastening system 80 for refastenably securing the training pants about the waist of the wearer. The illustrated fastening system 80 includes first fastening components 82 adapted for refastenable engagement to corresponding second fastening components 84. In one embodiment, one surface of each of the first fastening components 82 comprises a plurality of engaging elements which project from that surface. The engaging elements of the first fastening components 82 are adapted to repeatedly engage and disengage engaging elements of the second fastening components 84. The fastening components 82, 84 can comprise separate elements bonded to the respective side panels 134, 34, or they may be integrally formed with the side panels. Thus, unless otherwise specified, the term "fastening component"
includes separate components which function as fasteners, and regions of materials such as the side panels 34, 134 which function as fasteners. Moreover, a single material can define multiple fastening components to the extent that different regions of the material function as separate fasteners. The fastening components 82, 84 can be located on the side panels 134, 34, between the side panels such as on the absorbent chassis 32, or a combination of the two. The fastening components 82, 84 can comprise any refastenable fasteners suitable for absorbent articles, such as adhesive fasteners, cohesive fasteners, mechanical fasteners, or the like. In particular embodiments the fastening components comprise mechanical fastening elements for improved performance. Suitable mechanical fastening elements can be provided by interlocking geometric shaped materials, such as hooks, loops, bulbs, mushrooms, arrowheads, balls on stems, male and female mating components, buckles, snaps, or the like.
A refastenable fastening system 80 allows for easy inspection of the interior of the pant-like product. If necessary, the fastening system 80 also allows the pant 20 to be removed quickly and easily. This is particularly beneficial when the pant contains messy excrement. For training pants 20, the caregiver can completely remove the pant-like product and replace it with a new one without having to remove the child's shoes and clothing.
In the illustrated embodiment, the first fastening components 82 comprise hook fasteners and the second fastening components 84 comprise complementary loop fasteners. In another particular embodiment, the first fastening components 82 comprise loop fasteners and the second fastening components 84 comprise complementary hook fasteners. Alternatively, the fastening components 82, 84 can
comprise interlocking similar surface fasteners, adhesive or cohesive fastening elements such as an adhesive fastener and an adhesive-receptive landing zone or material; or the like. Although the training pants 20 illustrated in Fig. 1 show the back side panels 134 overlapping the front side panels 34, which is convenient, the training pants 20 can also be configured so that the front side panels overlap the back side panels. One skilled in the art will recognize that the shape, density and polymer composition of the hooks and loops may be selected to obtain the desired level of engagement between the fastening components 82, 84. A more aggressive hook material may comprise a material with a greater average hook height, a greater percentage of directionally-aligned hooks, or a more aggressive hook shape. Loop fasteners typically comprise a fabric or material having a base or backing structure and a plurality of loop members extending upwardly from at least one surface of the backing structure. The loop material can be formed of any suitable material, such as acrylic, nylon, polyethylene, polypropylene or polyester, and can be formed by methods such as warp knitting, stitch bonding or needle punching. Loop materials can also comprise any fibrous structure capable of entangling or catching hook materials, such as carded, spunbonded or other nonwoven webs or composites, including elastomeric and nonelastomeric composites. Suitable loop materials are available from Guilford Mills, Inc., Greensboro, North Carolina, U.S.A. under the trade designation No. 36549. Another suitable loop material can comprise a pattern un-bonded web as disclosed in U.S. Patent 5,858,515 issued January 12, 1999 to Stokes et al .
Hook fasteners typically comprise a fabric or material having a base or backing structure and a plurality of hook members extending upwardly from at least one surface of the
backing structure. In contrast to the loop fasteners which desirably comprise a flexible fabric, the hook material advantageously comprises a resilient material to minimize unintentional disengagement of the fastener components as a result of the hook material becoming deformed and catching on clothing or other items. The term "resilient" as used herein refers to an interlocking material having a predetermined shape and the property of the interlocking material to resume the predetermined shape after being engaged and disengaged from a mating, complementary interlocking material. Suitable hook material can be molded or extruded from nylon, polyethylene, polypropylene or another suitable material. Suitable single-sided hook materials for the fastening components 82, 84 are available from commercial vendors such as Velcro Industries B.V., Amsterdam, Netherlands or affiliates thereof, and are identified as Velcro HTH-829 with a uni-directional hook pattern and having a thickness of about 0.9 millimeters (35 mils) and HTH-851 with a unidirectional hook pattern and having a thickness of about 0.5 millimeters (20 mils) ; and Minnesota Mining & Manufacturing Co., St. Paul, Minnesota U.S.A., including specific materials identified as CS-600.
In accordance with the present invention, the loop type fastener is preferably made of a stretchable material, such as an extensible or elastic material, which may include a stretch bonded laminate, and which may be elastomeric. In particular embodiments, the loop material can be mounted to a base of stretchable material so the fastening component formed by the loop material is stretchable. Alternatively, the loop material may be a retractable material which retracts upon application of heat.
With particular reference to Fig. 3, the fastening components 82 are disposed on the inner surface 28 of the
back side panels 134. The fastening components 82 are desirably positioned along the outer edges 68 of the back side panels 134, and abutting or adjacent to the waist end edge 72. In certain embodiments, for example, the fastening components 82 can be spaced inward from the outer edges 68 of the front side panels 34, in the range of about 0 to 25 mm. With particular reference to Fig. 2, the second fastening components 84 are disposed on the outer surface 30 of the front side panels 134. The second fastening components 84 are sized to receive the first fastening components 82 and are desirably positioned along the outer edges 68 of the front side panels 34, and abutting or adjacent to the waist end edge 72. As an example, the second fastening components 84 can be spaced inward from the outer edges 68 of the back side panels 134, in the range of about 0 to about 25 mm. It is understood that the fastening components 82, 84 may also extend laterally out beyond the outer edges 68 of the side panels 34, 134. Where the first fastening components 82 comprise loop fasteners disposed on the inner surface 28 and the second fastening components 84 comprise hook fasteners disposed on the outer surface 30, the first fastening components can be sized larger than the second fastening components to ensure coverage of the rigid, outwardly- directed hooks . The fastening components 84, 82 can be adhered to the respective side panels 34, 134 by any means known to those skilled in the art such as adhesive bonds, ultrasonic bonds or thermal bonds. The fastening components 82, 84 may comprise separate fastening elements or distinct regions of an integral material. For example, the training pants 20 can include an integral second fastening material disposed in the front waist region 22 for refastenably connecting to the first fastening components 82 at two or more different
regions, which define the second fastening components 84 (Fig. 1) . In a particular embodiment, the fastening components 82, 84 can comprise integral portions of the waist regions 24, 22. For instance, one of the elastomeric front or back side panels 34, 134 can function as second fastening components 84 in that they can comprise a material which is releasably engageable with fastening components 82 disposed in the opposite waist region.
The fastening components 82, 84 of the illustrated embodiments are rectangular, although they may alternatively be square, round, oval, curved or otherwise non-rectangularly shaped. In particular embodiments, each of the fastening components 82, 84 has a length aligned generally parallel to the longitudinal axis 48 of the training pants 20 and a width aligned generally parallel to the transverse axis 49 of the training pants. For a child of about 9 to about 15 kilograms (20-30 pounds) , for example, the length of the fastening components 82, 84 is desirably from about 5 to about 13 centimeters, such as about 10 centimeters, and the width is desirably from about 0.5 to about 3 centimeters, such as about 1 centimeter. With particular embodiments, the fastening components 82, 84 can have a length-to-width ratio of about 2 or greater, such as about 2 to about 25, and more particularly about 5 or greater, such as about 5 to about 8. For other embodiments such as for adult products, it may be desirable for one or more of the fastening components to comprise a plurality of relatively smaller fastening elements. In that case, a fastening component or individual fastening elements may have an even smaller length-to-width ratio, for example, of about 2 or less, and even about 1 or less .
As shown in Fig. 1, when the fastening components 82, 84 are releasably engaged, the side edges 36 of the absorbent
chassis 32 in the crotch region 26 define the leg openings 52, and the waist edges 38 and 39 of the absorbent chassis, including the waist end edges 72 of the side panels 34, 134, define the waist opening 50. For improved formation of the leg openings 52, it can be desirable in some embodiments for the front side panels 34 to be longitudinally spaced from the back side panels 134 as shown in Figs. 2 and 3. For example, the front side panels 34 can be longitudinally spaced from the back side panels 134 by a distance equal to about 20 percent or greater, particularly from about 20 to about 60 percent, and more particularly from about 35 to about 50 percent, of the overall length of the pants 20.
When engaged, the fastening components 82, 84 define refastenable engagement seams 88 (Fig. 1) that desirably although not necessarily extend substantially the entire distance between the waist opening 50 and the leg openings 52. More specifically, the engagement seams 88 can cover about 80 to 100 percent, and particularly about 90 to about 98 percent, of the distance between the waist opening 50 and each leg opening 52, which distance is measured parallel to the longitudinal axis 48. To construct the engagement seams 88 to extend substantially the entire distance between the waist and leg openings 50 and 52, the fastening components 82, 84 can be formed to cover about 80 to 100 percent, and more particularly about 90 to about 98 percent, of the distance between the waist end edge 70 and the leg end edge 72 of the side panels 34, 134. In other embodiments, the fastening components can comprise a plurality of smaller fastening elements covering a smaller portion of the distance between the waist opening 50 and the leg openings 52, for example, about 20 to about 70 percent, but spaced apart to span a larger percentage of the distance between the waist opening and the leg openings .
For the engagement seams 88 to be located at the sides of the wearer, it can be particularly desirable for the transverse distance between the fastening components 82 of the back side panels 134 to be substantially equal to the transverse distance between the fastening components 84 of the front side panel 134. The transverse distance between a set of fastening components 82, 84 is measured parallel to the transverse axis 49 between the longitudinal center lines of the fastening component, measured with the side panels 34, 134 in an unstretched condition. Alternatively, the lateral spacing between the fastening components 82 may be greater or less than the lateral spacing between the fastening components 84. It is also contemplated that fastening components 82 (and/or the fastening components 84) may not be laterally opposite each other, or may only be partially laterally opposite each other, such as by being offset longitudinally, without departing from the scope of this invention.
Figures 25 and 26 illustrate training pants 21 in which one or both of the fastening components 82, 84 comprise integral portions of the waist regions of the absorbent chassis 32. For instance, either the front or back side panels 34 and 134 can function as one of the fastening components, e.g., fastening components 84, in that they can comprise a material which is releasably engageable with fastening components, e.g., fastening components 82, disposed in the opposite waist region. As illustrated in Figures 25 and 26, the side panels 134 are made completely of a stretchable loop material although, alternatively, these side panels could be made of loop material only at the outer ends thereof engagement with the hook material occurs and the remainder of the side panels can be made of some other,
preferably stretchable, material and joined along abutting edges thereof .
Figs. 4-6 generally illustrate apparatus of the present invention for making a pre-fastened garment, and more particularly for making the pre-fastened, refastenable training pants 20 shown in Fig. 1. The apparatus comprises an assembly section, generally indicated at 100 in Fig. 4, for making partially assembled pants 102 in an unfolded configuration, a folding section, generally indicated at 200 in Fig. 5, for folding the partially assembled pants generally at the crotch region 26, and a seaming section, generally indicated at 250 in Fig. 6, for engaging the fastening components 84, 82 of the respective front and back side panels 34, 134 to form the pre-fastened training pants. The various components of the training pants 20 can be connected together in the assembly section 100 by any means known to those skilled in the art such as, for example, adhesive, thermal and/or ultrasonic bonds. Desirably, most of the components are connected using ultrasonic bonding for improved manufacturing efficiency and reduced raw material costs. Certain garment manufacturing equipment which is readily known and understood in the art, including frames and mounting structures, ultrasonic and adhesive bonding devices, transport conveyors, transfer rolls, guide rolls, tension rolls, and the like, have not been shown in Figs. 4 and 5. Suitable absorbent supply mechanisms, web unwinds, conveyor systems, registration systems, drive systems, control systems and the like, for use with the present apparatus are disclosed in U.S. Patent No. 5,766,389 issued June 16, 1998 to Brandon et al . , the entire disclosure of which is incorporated herein by reference. Also, the outer cover graphics 61 are not shown in Figs. 4-7.
With particular reference to the assembly section 100 shown in Fig. 4, a continuous supply of material 104 used to form the bodyside liner 42 is provided from a supply source 106. The supply source 106 can comprise for example any standard unwind mechanism, which generally includes a pair of spindles, a festoon assembly, and a dancer roll for providing bodyside liner material 104 at a desired speed and tension. Various components can be disposed on and/or bonded to the bodyside liner material 104 as the material travels in a machine direction identified by arrow 108. In particular, a surge layer can be provided at an application station 110 and disposed on and/or bonded to the bodyside liner material 104. The surge layer can comprise either a continuous web or discrete sheets. Additionally, a containment flap module 112 can be provided downstream from the supply source 106 for attaching pre-assembled containment flaps to the bodyside liner material 104. As various components are added in the assembly section 100, a continuously moving product assemblage 113 is formed. The product assemblage 113 will be cut downstream to form the partially assembled, discrete training pants 102.
A plurality of absorbent assemblies 114 can be provided from a suitable supply source 115. The supply source 115 can be any conventional mechanism for supplying the absorbent assemblies 114. Generally, a conventional supply source can include a hammermill for forming fluff fibers and, if desired, for providing an enclosure for mixing superabsorbent material with the fluff fibers, and then depositing the fluff and superabsorbent material on a forming drum having a desired absorbent design. The individual absorbent assemblies 114 can be disposed intermittently on the continuously moving bodyside liner material 104, one for each pair of training pants. The position of the absorbent assemblies 114 can be
registered with the position of the surge material, if employed. The absorbent assemblies 114 can be bonded to one or more other components using adhesives or other suitable means. Alternatively, composite absorbent materials can be fed into the converting process from rolls or compressed packages, such as festooned bales.
Continuous webs of material 116 used to form the side panels 34, 134 can be provided from suitable supply sources 117. The supply sources 117 can comprise one or more standard unwind mechanisms. The side panel material 116 can be cut into individual strips 118 and positioned partially on the bodyside liner material 104 using an applicator device 120. In the cross machine direction, the individual strips 118 desirably extend laterally outward from the bodyside liner material 104 (see Figs. 4 and 7) and overlap the bodyside liner material by an amount such as about 2 or more centimeters to permit bonding of the strips to the bodyside liner and/or the containment flap material . In the machine direction 108, the position of the strips 118 can be registered relative to the absorbent assemblies 114 so that the product assemblage 113 can be cut between the absorbent assemblies with each strip 118 of side panel material 116 forming both a front side panel 34 and a back side panel 134 of consecutive pants 102. One suitable applicator device 120 is disclosed in U.S. Patents 5,104,116 issued April 14, 1992 and 5,224,405 issued July 6, 1993 both to Pohjola, which are incorporated herein by reference. The applicator device 120 can comprise a cutting assembly 122 and a rotatable transfer roll 124. The cutting assembly 122 employs a rotatable knife roll 126 and a rotatable vacuum anvil roll 128 to cut individual strips 118 from the continuous side panel material 116. The strips 118 cut by a blade on the knife roll 126 can be maintained on the
anvil roll 128 by vacuum and transferred to the transfer roll 124.
The rotatable transfer roll 124 can comprise a plurality of rotatable vacuum pucks 130. The vacuum pucks 130 receive the strips 118 of material 116 from the cutting assembly 122 and rotate and transfer the strips to the continuously moving bodyside liner material 104. When the strips 118 are positioned as desired relative to the bodyside liner material 104, the strips are released from the pucks 130 by extinguishing the vacuum in the pucks. The pucks 130 can continue to rotate toward the cutting assembly 122 to receive other strips . As disclosed by Van Gompel et al . , the material 116 used to form the side panels can alternatively be provided in continuous form and pressurized fluid-jets or a rotary die cutter can be employed to cut the material to form leg openings 52. Still alternatively, the side panels 34, 134 of the training pants 20 can be provided by portions of the bodyside liner 42 and/or outer cover 40.
A continuous supply of material 140 used to form the outer cover 40 can be provided from a supply roll 142 or other suitable source. The outer cover material 140 can be transported over a laminator roll 144 and banded to the bodyside liner material 104. The absorbent assemblies 114 are thereby sandwiched between the continuous materials 104 and 140. The inward portions of the strips 118 of side panel material 116 can also be disposed between the bodyside liner material 104 and the outer cover material 140. Alternative configurations for attaching the side panel material 116 are disclosed by Van Gompel et al . Various components such as leg elastics 58 or waist elastics 54 and 56 can be bonded to the outer cover material 140 at an application station 146 prior to uniting the bodyside liner and outer cover materials 104 and 140. Alternatively, leg elastics or waist elastics can be
initially bonded to the bodyside liner material 104 or another material .
Bonding devices 148 such as ultrasonic bonders can be employed downstream from the laminator roll 144 to bond the bodyside liner material 104, side panel material 116 and outer cover material 140. For example, these materials can be transported between a rotary ultrasonic horn and an anvil roll. Suitable rotary ultrasonic horns are described in U.S. Patent 5,110,403 to Ehlert, which is incorporated herein by reference. Such rotary ultrasonic horns generally have a diameter of from about 5 to about 20 centimeters and a width of from about 2 to about 15 centimeters. Alternatively, the ultrasonic horn may be a stationary ultrasonic horn as is also known to those skilled in the art. Other suitable ultrasonic horns and ultrasonic bonders are commercially available from Branson Sonic Power Company, Danbury, Connecticut, U.S.A. The bonding devices 148 could otherwise be a thermal or adhesive bonder as are well known.
The continuously moving product assemblage 113 next advances to a fastener application station 150 where fastening components 82, 84 are bonded to the strips 118 of side panel material 116. The location of the fastening components on the composite is a function in part of the configuration of the assembly section 100. As shown in Fig. 4, the assembly section 100 of the illustrated embodiment is configured so that the upward facing surface of the product assemblage 113 will become the outer surface 30 of the training pants 20 and the downward facing surface will become the inner surface 28. Moreover, the illustrated assembly section 100 is configured to produce partially assembled training pants 102 having the front waist region 22 of a leading garment connected to the back waist region 24 of a trailing garment. However, it is understood that the
assembly section 100 could alternatively employ any combination of different orientations. For example, the upward facing surface of the product assemblage 113 could form the inner surface 28 of finished garments. Additionally or alternatively, the back waist region 24 of a leading garment can be connected to the front waist region 22 of the trailing garment, or the garments can be arranged in a front- to-front/back-to-back relationship. Still alternatively, the assembly section 100 could be constructed as a cross-machine direction process wherein the longitudinal axis 48 of each garment could be perpendicular to the machine direction 108 during part or all of the assembly process.
The locations of the fastening components 82, 84 in this embodiment are best illustrated in Fig. 7, which shows a portion of the product assemblage 113 moving in the direction of arrow 108 immediately following the fastener application station 150. Each individual strip 118 of side panel material 116 defines a leading edge 152, a trailing edge 154, a distal edge 156 and an interior edge 158. A dashed line 159 illustrates the location at which the product assemblage 113 can subsequently be cut to provide the discrete partially assembled training pants 102. Based on the illustrated orientation of the continuously moving product assemblage 113, the first fastening components 82 can be bonded to the underside of the strips 118 and the second fastening components 84 can be bonded to the top of the strips. Additionally, the first fastening components 82 can be disposed relatively closer to the trailing edge 154 and the second fastening components 84 can be disposed relatively closer to the leading edge 152. The first fastening components 82 can be spaced in the machine direction 108 from the second fastening components 84 so that the cut line 159 passes therebetween.
With reference again to Fig. 4, continuous webs of a second fastener material 160 used to form the second fastening components 84 can be provided from supply rolls 162 or other suitable sources. The second fastener materials 160 can be cut into individual second fasteners 84 by cutting assemblies 164 or other suitable devices. The illustrated cutting assemblies 164 include rotatable knife rolls 166, rotatable vacuum anvil rolls 167, and rotatable backing rolls 168. The continuous second fastener materials 160 can be cut by blades on the knife rolls 166, maintained on the anvil rolls 167 by vacuum, and adhered on the top surfaces of the strips 118 of side panel material 116.
Similarly, continuous webs of first fastener material 170 used to form the first fastening components 82 can be provided from supply rolls 172 or other suitable sources. The first fastener materials 170 can be cut into individual first fastening components by cutting assemblies 174 or other suitable devices. The illustrated cutting assemblies 174 include rotatable knife rolls 176, rotatable vacuum anvil rolls 177, and rotatable backing rolls 178. The continuous first fastener materials 170 can be cut by blades on the knife rolls 176, maintained on the anvil rolls 177 by vacuum, and adhered on the undersides of the strips 118 of side panel material 116. It is contemplated that other arrangements can be used to attach the fastening components 82, 84 to the side panel material 116. For example, the fastening components 82, 84 can be applied to the side panel material 116 prior to uniting the side panel material with the bodyside liner material 104 and/or the outer cover material 140; the fastening components can be applied to the bodyside liner material 104 and/or outer cover material 140, whether separate side panels 34, 134 are used or not; portions of
other components such as the bodyside liner and/or outer cover can form one or more of the fastening components; the separate side panels or integral side panels can themselves form one or more of the fastening components; the fastening components 82, 84 can be attached as pre-engaged composites or the like without departing from the scope of this invention.
After the fastening components 82, 84 are disposed on the strips 118 of side panel material 116, bonding devices 180 such as ultrasonic bonders can be employed to bond the fastening components to the strips. For example, the strips 118 can be transported between a rotary ultrasonic horn and an anvil roll, which devices are positioned on each side of the process at the cross machine direction location of the fastening components 82, 840. Particular ultrasonic bond patterns comprising individual, circular bonds which are compatible with mechanical fastening materials are disclosed in U.S. Patent 5,660,666 issued August 26, 1997 to Dilnik et al . , which is incorporated herein by reference. Efficient arrangements for attaching the fastening components with nonadhesive bonding devices are further described in published U.S. Patent Application No. US2002-0000291, filed on May 15, 2001 by J. D. Coenen et al . and titled "Methods For Making Garments With Fastening Components," which is incorporated herein by reference. For secure attachment, it may be desirable to attach the fastening components 82, 84 to the side panel material 116 with both adhesive and thermal bonds. Suitable attachment adhesives are available from commercial vendors such as Findley Adhesive, Inc., Wauwatosa, Wisconsin, U.S.A.
In particular embodiments, the bonding devices 180 can provide timed, non-uniform bonding of the fastening components to the side panel material 116. The degree of
bonding, such as the number of bonds per unit area or the bond strength per unit area, can be greater in certain target areas compared to non-target areas. Enhanced bonding in target areas can be beneficial particularly near the waist and leg openings 50 and 52 to reduce delamination of the fastening components from the side panel material 116. Thus, the bonding devices 180 can be adapted to create relatively more bonds or stronger bonds between the fastening components 82, 84 and the side panel material 116 when the side panel material 116 reaches a particular machine direction 108 location. In one particular embodiment, the target areas correspond to portions of the fastening components 82, 84 near the waist edges 38 and 39. The bonding devices 180 can be registered to provide a relatively higher degree of bonding which begins while disposed on one fastening component (such as the fastening component 84 in Fig. 7) , continues through the region where the product assemblage 113 will subsequently be cut (see cut line 159 in Fig. 7) , and ends after being disposed on another fastening component (such as fastening component 82) . Alternatively, the bonding devices 180 can destroy engaging elements of the fastening components 82, 84 in the target areas, so that the fastening components will be less able to aggressively attach to one another in the target areas. The strips 118 of side panel material 116 can be trimmed if desired, for example to provide angled and/or curved leg end edges 70 in the back waist region 24 (Figs. 2 and 3) . To this end, the assembly section 100 can include a die cutting roll 182 and a backing roll 184. In the illustrated embodiment, a portion of each strip 118 is trimmed from the trailing edge 154 (Fig. 7) in order to form the angled and/or curved leg end edges 70 in the back waist region 24.
The method and apparatus to this point provides a continuous web of interconnected and partially assembled training pants moving in the direction indicated by arrow 108. This continuously moving product assemblage 113 is passed through a cutter 186 which selectively cuts the web into discrete, partially assembled training pants 102. Such cutters 186 are generally known to those skilled in the art and can include, for example, the combination of a cutting roll 187 and an anvil roll 188 through which the web travels. The anvil roll 188 can include a hardened steel rotating roll while the cutting roll 187 can include one or more flexible hardened steel blades clamped onto another rotating roll. The pinching force between the blade on the cutting roll 187 and the anvil roll 188 creates the cut. The cutting roll 187 can have one or more blades depending upon the desired distance between the cuts. The cutter 186 can further be configured to provide a spacing between the individual cut pieces after they are cut . Such a spacing can be provided by transferring the cut pieces away from the cutter at a higher speed than the speed at which the web is provided to the cutter.
With particular reference now to Figs. 5, 8 and 9, the discrete partially assembled training pants 102 are delivered to and folded at the folding section 200 using any suitable folding mechanism 202. For example, the training pants 102 can be folded about a fold line generally bisecting the training pants such as laterally through the crotch region 26. As such, the waist regions 22 and 24 the training pants 102 are positioned in opposed relationship, with the side panels 34 and 134 extending laterally outward parallel to the transverse axis 49 of the training pants. Desirably, each of the training pants 102 is consistently folded about the fold line such that the front and back waist edges 38 and 39 of the training pants align with each other.
A variety of folding mechanisms 202 can be used, such as blade folders, linear folders, book folders, tucker blades or the like. The specific type selected for a given application may depend upon the type of garment being manufactured and the type of fastening mechanism used to secure the garment in a pants configuration. In the illustrated embodiment, the folding mechanism 202 controls the side panels 34, 134 during folding so that the refastenable fastening components 82, 84 are inhibited against engaging one another or engaging another material during the folding operation. Other arrangements for maintaining separation of the side panels 34, 134 and fastening components 82, 84 during folding are disclosed in PCT Application No. WO 01/87210, filed by J. D. Coenen et al . and titled "Folding And Manufacture Of Pants," which is incorporated herein by reference.
The illustrated blade folding mechanism 202 comprises a plurality of rotating folding or tucker blades 240 (Fig. 9) which are configured to contact the training pants 102 along the fold line. Rotation of the folding blades 240 can force the training pants 102 into a nip 204 between two rotating folding conveyors 206 and 208 causing the training pants to fold about the fold line. The folding conveyors 206 and 208 can form part of a transport system for moving the folded training pants 102 in the machine direction 108 (Fig. 8) . The folded training pants 102 are illustrated as being transported in the machine direction 108 with the crotch region 26 leading the waist regions 22 and 24. Alternatively, the process and apparatus could be modified so that the waist regions lead the crotch region (not shown) . The series of unfolded, discrete training pants 102 can be transferred from the vacuum anvil roll 188 (Fig. 4) of the cutter 186 to the upper folding conveyor 206 (Figs. 5, 8 and 9) . The training pants 102 can be held by vacuum on the upper
folding conveyor 206 and transported toward the nip 204 formed between the folding conveyors 206 and 208. While being transported toward the nip 204, the side panels 34, 134 can be smoothed out or straightened if desired by various means including fluid stabilizing devices. For example, air knives 215 (Fig. 8) , air bars, air nozzles or the like can be mounted in proximity to the upper folding conveyor to provide a stream of fluid directed toward the side panels to stabilize and/or straighten the side panels. The air knives 215 can blow the side panels 34, 134 against skid plates 216 positioned transversely outward from the upper folding conveyor belt 212. Alternatively, or in addition thereto, the upper folding conveyor 206 can incorporate fluid stabilizing devices (not shown) consisting of fluid manifolds operatively connected to a high pressure fluid source to fluidly shake the side panels 34, 134. The fluid stabilizing devices (not shown) desirably prevent folding of the side panels 34, 134 as the training pants 102 move along the upper folding conveyor 206. Sensing devices can also be employed at this point to detect products that have folded side panels or that are misaligned relative to the machine center line. The product folding nip 204 can be formed between a timed vacuum nose roll 218 of the upper folding conveyor 206 and a timed vacuum nose roll 219 of the lower folding conveyor 208 (Figs. 5 and 8) . As the leading edge of each pair of pants 102 is introduced onto the upper nose roll 218, a rotary valve 229 can be used to disrupt the vacuum draw of the nose roll 218 of the upper folding conveyor 206. This allows the leading edge of the pants 102 to pass by the nose roll 218 without getting drawn into the nip 204.
Alternatively, the vacuum source can be temporarily disconnected from the nose roll 218 of the upper folding conveyor 206. Any suitable control system (not shown) may be
used to control operation of the vacuum nose rolls 218, 219. For example, in certain embodiments, compressed air nozzles or jets (not shown) can be used to cycle vacuum through the nose rolls 218, 219, such as by injecting compressed air into interior chambers (not shown) of the nose rolls to negate the vacuum therein.
A product control drum 220 can guide the leading half of the training pants 102 onto a curved transfer plate 222 (Figs. 5 and 8) . The product control drum 220 can comprise a plurality of vacuum pucks 224 which rotate in the direction of arrow 225. The illustrated product control drum 220 includes four vacuum pucks 224 to guide four training pants 102 per revolution. Rotation of the product control drum 220 can be timed so that a vacuum puck 224 grabs the leading half of a training pants 102 and transfers the leading edge onto the curved transfer plate 222. The absorbent chassis 32 and/or side panels 134 of the leading half can be carried on a vacuum puck 224 past the nose roll 219 of the lower folding conveyor 208. Compressed air can be introduced inside this lower nose roll 219 at this point to negate vacuum draw and to permit the entire leading edge and side panels 134 to transfer onto the curved transfer plate 222. Alternatively of course, the vacuum source can be temporarily disconnected from the nose roll 219. With reference to Fig. 9, the opposed tucker blades 240 move in an orbital manner to pass through the vertical path of the training pants 102. The tucker blades 240 can contact the crotch region 26 of the pants 102 and insert the crotch region into the folding nip 204. As this happens, the leading half of the pants 102 reverses direction over the curved transfer plate 222 and is pulled into the nip 204. The vacuum puck 224 can cease drawing vacuum at this point to release the leading half. Correspondingly, the trailing half of the
pants 102 is pulled around the upper nose roll 218. Thus, both halves of the training pants 102 can change from motion in a generally vertical plane to motion between the folding conveyors 206 and 208 in a generally horizontal plane. The illustrated folding mechanism 202 can maintain separation between the front and back side panels 34, 134. As the pants 102 enter the folding nip 204, compressed air can be shut off to the upper nose roll 218 so that the side panels 34 of the trailing half are drawn by vacuum to the upper nose roll. The trailing side panels 34 are thus drawn to the upper nose roll 218 and follow its rotation around the roll and over side panel separation plates 230 (Figs. 8 and 10) . Similarly, as the leading half of the pants 102 is pulled into the folding nip 204, compressed air can be shut off to the lower nose roll 219 so that the side panels 134 of the leading half are drawn by vacuum to the lower nose roll. The leading side panels 134 are thus drawn to the lower nose roll 219 and follow its rotation around the roll and beneath the side panel separation plates 230. Figure 10 illustrates a portion of partially assembled training pants 102 positioned between the upper and lower folding conveyors 206 and 208 at a location downstream from the nose rolls 218 and 219. At this point, the training pants 102 have been folded in half and transported in the machine direction 108 (Fig. 8) by the conveyors 206 and 208. The illustrated folding mechanism 202 can thus maintain the front side panels 34 separated from the back side panels 134 during folding.
Each folding conveyor 206 and 208 as illustrated in greater detail in Fig. 10 can comprise a frame structure 210, a plurality of rotatable pulleys 211 associated with the frame structure, and a continuous belt 212 carried on the pulleys. A drive system and conveyor shaft (not shown) can be
used to rotatively drive one or more of the pulleys. The folding conveyors" 206 and 208 can comprise vacuum conveyors as are well known in the art, in which case the continuous belt can be formed of a fluid permeable material . The folding conveyors desirably transport the training pants 102 with the longitudinal center line of the pants traveling on the longitudinal center line of the conveyors. As depicted, the front and back side panels 34, 134 can project laterally outward from the frame structure 210, outstretched in the cross-machine direction.
While traveling on the folding conveyors 206 and 208, the side panels 34, 134 can be smoothed out or straightened if desired by various means including fluid stabilizing devices (not shown) . Suitable fluid stabilizing devices can comprise air knives, air bars, air nozzles, vacuum devices or the like to provide a stream of fluid directed toward the side panels. The fluid stabilizing devices can be incorporated within either or both of the folding conveyors 206 and 208 or can comprise separate devices positioned in proximity to the conveyors.
As a result of the illustrated folding mechanism 202, the front waist region 22 and front side panels 34 of the partially assembled training pants 102 as shown in Fig. 10 are disposed above the back waist region 24 and back side panels 134. The fastening components 82 are disposed on the inner surface 28 of the back side panels 134 and the fastening components 84 are disposed on the outer surface 30 of the front side panels 34. The separation plates 230 can extend in the machine direction 108 to maintain separation between the front and back side panels 34, 134. The separation plates 230 can comprise a low friction material or coating, such as: stainless steel; Teflon ; aluminum; ultra- high molecular weight polyethylene (UHMW-PE) ;
polyoxymethylene (acetals) , for instance a homopolymer available from E. I. Du Pont de Nemours and Company, Wilmington, Delaware, USA under the tradename DELRIN; or the like. In particular embodiments, the separation plates 230 can comprise a thin layer of Teflon®, UHMW-PE, DELRIN or the like glued to a plate formed of steel, aluminum or the like. The separation plates 230 can be mounted using suitable support members 232 (Fig. 10) to either the folding conveyors 206 or 208 or other suitable frame structure (not shown) . It is also contemplated that the separation plates 230 could include air stabilization devices (not shown) to straighten and maintain stability of the side panels 34, 134.
From the folding station 200, the continuous stream of discrete, partially assembled and folded training pants 102 enters a seaming section 250 (Fig. 6) and is transported therethrough in a machine direction 108 indicated by the direction arrow in Fig. 6. In general, the seaming section 250 controls the unattached side panels 34, 134 so as to position the fastening components 82, 84 in at least partially opposed relationship with each other, then bring the fastening components together into fastening engagement to define the engagement seams 88, and promote increased engagement between the fastening components along the engagement seams. The seaming section 250 thus converts the discrete, partially assembled and folded training pants 102 into pre-fastened training pants 20 (Fig. 1) having the waist opening 50 and leg openings 52.
Construction and operation of the seaming section 250 is further described herein with particular reference to Figs. 11-21. Figs. 11 and 12 respectively illustrate upstream and downstream portions of the seaming section 250 and Fig. 13 illustrates a lower portion of the seaming section. Figs. 14-21 are sections taken at sequential locations along the
seaming section 250. For ease of explanation, these sections illustrate only one side (e.g., the right hand side) of the seaming section 250 and the training pants 102 conveyed therethrough, it being understood that the left hand side of the seaming section is constructed and operates substantially similar to the right hand side.
With particular reference to Figs. 6, 11 and 14, the seaming section 250 comprises upper and lower alignment conveyors, generally indicated as 256 and 258, respectively, which broadly define a transport system for transporting discrete, partially assembled training pants 102 from the upper and lower folding conveyors 206 and 208 (Fig. 5) through the seaming section in the machine direction 108. More specifically, the alignment conveyors 256 and 258 define therebetween a pant transport plane, which in the illustrated embodiment is generally horizontal, in which the training pants 102 are transported through the seaming section 250. As illustrated, the upper alignment conveyor 256 comprises frame structure 260, one or more vacuum chambers 262 (Fig. 14) defined within the frame structure, one or more vacuum cover plates 264 (Fig. 14) mounted on the frame structure and one or more continuous fluid-permeable belts 266 carried on a plurality of rotatable pulleys 268 or other suitable devices. Similarly, the lower alignment conveyor 258 comprises frame structure 270, a vacuum chamber 272 (Fig. 14) defined within the frame structure, a vacuum cover plate 274 (Fig. 14) mounted on the frame structure and a continuous fluid- permeable belt 276 carried on a plurality of rotatable pulleys 278 or other suitable devices. The vacuum cover plates 264 and 274 and related equipment- can be adjustable if desired to accommodate various pants sizes. A drive system (not shown) and conveyor shaft (not shown) can be used to rotatively drive one or more of the pulleys 268 and 278. The
vacuum chambers 262 and 272 can be operatively connected to a source of vacuum (not shown) and the vacuum cover plates 264 and 274 can be provided with a plurality of holes 269 and 279, respectively. With reference to Fig. 14, the seaming section 250 is also illustrated and described herein with the training pants 102 oriented such that the front waist region 22 is drawn against the upper alignment conveyor 256 and the back waist region 24 is drawn against the lower alignment conveyor 258. Thus, the front side panels 34 are initially positioned above the back side panels 134, with the fastening component 84 of the front side panel facing up (e.g., away from the fastening component 82 of the back side panel) . However, it is understood that the pants 102 may be inverted, e.g., such that the back waist region 24 is drawn against the upper alignment conveyor 256 while passing through the seaming section 250, without departing from the scope of this invention. Also, while the seaming section 250 of the illustrated embodiment assembles pre-fastened training pants 20 with the back side panel 134 overlapping the front side panel 34 as shown in Fig. 1, it is understood that the seaming section 250 could be configured so that the front side panel overlaps the back side panel after passing through the seaming section. The upper alignment conveyor 256 of the illustrated embodiment has an operative width sufficient to draw the full width of the front waist region 22 and front side panels 34 of the training pants 102 against the upper conveyor belt 266 as shown in Fig. 14 fully or partially along the length of the seaming section 250. The lower alignment conveyor 258 is relatively narrow compared to the upper alignment conveyor 256 and has a width, for example, approximately equal to the width of the absorbent chassis 32, and more particularly the
back waist region 24 thereof. This permits the back side panels 134 to extend laterally out beyond the lower alignment conveyor 258. As another example, the width of the lower alignment conveyor 258 may generally correspond to the distance between the seams 66 (Fig. 2) along which the side panels 34 and 134 are bonded to the absorbent chassis 32.
The respective vacuum pressures acting on the upper and lower alignment conveyors 256, 258 are preferably sufficient to draw and retain the waist regions 22 and 24 of the training pants 102 against the respective conveyors to inhibit pinching of the waist regions between the conveyors. Vacuum control of the waist regions 22, 24 also inhibits lateral movement of the absorbent chassis 32 to thereby improve positioning and alignment of the side panels 34, 134. As an example, the upper alignment conveyor 256 can operate over a range of vacuum pressures, such as about one to about 30 inches of water or greater below atmospheric pressure. The lower alignment conveyor 258 can also operate over a range of vacuum pressures, such as in the range of about one to about 30 inches of water or greater below atmospheric pressure. Suitable conveyor mechanisms such as vacuum conveyors or non-vacuum conveyors are known in the art and available from various commercial vendors and thus will not be further described herein except to the extent necessary to set forth the present invention.
Referring to Figs. 6 and 11-13, the seaming section 250 further comprises side panel positioning devices, generally indicated at 330, for vertically and laterally positioning the back side panels 134 relative to the front side panels 34; side panel transfer devices, generally indicated at 430, for moving the respective fastening components 84, 82 of the side panels 34, 134 into engagement with each other to define the engagement seams 88; and tensioning assemblies, generally
indicated at 530 which promote increased engagement between the fastening components following initial engagement therebetween.
The positioning devices 330 of the illustrated embodiment are mounted on opposite sides of the lower alignment conveyor 258 as shown in Fig. 13, although it is understood that the positioning devices may instead be mounted on the upper alignment conveyor 256 or other suitable frame structure of the seaming section 250. Each positioning device 330 comprises an elongate tubular member 332 extending generally in the machine direction 108 from an upstream end (Figs. 6, 11) 334 adjacent an upstream end of the seaming section 250 to a downstream end 336. The tubular member 332 of the illustrated embodiment comprises opposed walls 344, 346 (Fig. 14) together defining a generally L-shaped cross- section of the tubular member and an internal flow chamber 340 extending longitudinally therethrough. A slot 342 (Fig. 14) is formed in the tubular member 342 in fluid communication with the internal flow chamber 340 and extends longitudinally substantially the length of the tubular member. The slot 342 faces laterally inward toward the lower alignment conveyor 258 for receiving the back side panel 134 into the internal flow chamber 340 (Fig. 14) . The walls 344, 346 of the tubular member 332 may be formed separately and secured together by suitable methods, or they may be formed integrally. It is also understood that the tubular member 332 and internal flow chamber 340 may be other than L-shaped in cross-section without departing from the scope of this invention. The tubular member 332 can be formed of any suitable material. For example, portions or surfaces of the tubular member 332 which may come into contact with the training pants 102 are desirably formed of a low friction material.
Suitable low friction materials or coatings include but are not limited to: stainless steel; low carbon steel; polycarbonate material; Teflon ; aluminum; ultra-high molecular weight polyethylene (UHMW-PE) ; polyoxymethylene (acetals), for instance a homopolymer available from E. I. Du Pont de Nemours and Company, Wilmington, Delaware USA under the tradename DELRIN; or the like.
The flow chamber 340 of the tubular member 332 is in fluid communication with a source of vacuum V via suitable vacuum hoses 350 (Figs. 6, 11) for drawing fluid, such as air, into the flow chamber via the slot 342 formed in the tubular member such that the fluid flows generally laterally outward within the flow chamber as indicated by the direction arrows in Fig. 14. The vacuum pressure within the flow chamber 340 can vary, for example, from about one to about 20 inches of water or greater below atmospheric pressure, and more particularly from about 2 to about 8 inches of water below atmospheric pressure. It is also contemplated that instead of or in addition to the vacuum pressure, pressurized fluid (not shown) can be directed into the internal chamber 340 via the slot 342 to establish the fluid flow laterally outward within the internal chamber.
The fluid flow within the internal flow chamber 340 is sufficient to draw the back side panel 134 laterally outward relative to the machine center line, and desirably at least partially into the flow chamber, to thereby promote straightening of the back side panel. The slot 342 and the flow chamber 340 are thus desirably sized to accommodate the back side panel 134 and fluid flow therethrough. For example, the slot 342 desirably has a width of about 5 millimeters to about 20 millimeters, and more desirably about 10 millimeters to about 15 millimeters. The walls 344, 346 of the tubular member 332 can converge or diverge relative to
one another, or be generally parallel as illustrated. The depth of the flow chamber 340 generally depends upon the application and the amount of back side panel 134 material to be received therein. For example, the internal flow chamber 340 may have a depth of about 10 to about 20 centimeters. As seen best in Figs. 14 and 15, the tubular member 332 of each positioning device 330 is positioned lower than the lower alignment conveyor 258 so that when the back side panel 134 is drawn into the flow chamber 340, the back side panel extends laterally outward and down from the back waist region 24 being held against the conveyor.
Now referring to Figs. 11 and 16-18, the side panel transfer devices 430 comprise vacuum conveyors spaced laterally outward of the lower alignment conveyor 258 a distance generally corresponding to the lateral positions of the fastening components 82 of the back side panels 134 as the panels exit the downstream end 336 of the positioning devices 330. More particularly, each side panel transfer device 430 comprises suitable frame structure 432, rotatable pulleys 434 (Figs. 6 and 11) associated with the frame structure, a vacuum chamber 436 (Fig. 16) defined within the frame structure, a vacuum cover plate 438 (Fig. 16) mounted on the frame structure, and a continuous belt 440 carried by the pulleys. A drive mechanism (not shown) and corresponding conveyor shaft (not shown) can be used to rotatively drive one or more of the pulleys 434. The side panel transfer devices 430 can be aligned parallel to the machine direction 108 as shown in Fig. 13 or canted inward or outward, for example, to improve side panel 34, 134 alignment with the machine direction.
Each side panel transfer device 430 angles up toward the pants transport plane defined by the upper and lower alignment conveyors 256, 258 as the device extends in the
machine direction 108 from an upstream end 442 disposed slightly upstream and below the downstream end 336 of the positioning device 330, to a downstream end 444 disposed in closely spaced relationship with the upper alignment conveyor 256. The side panel transfer device 430 and the upper alignment conveyor 256 thus define a nip therebetween at the downstream end of the device, the purpose of which will become apparent .
The side panel transfer device 430 can alternatively comprise other devices (not shown) for sequentially or simultaneously affecting upward movement of the laterally outward portion of the back side panel 134. By way of illustration, suitable side panel transfer devices 430 can alternatively comprise disks or wheels, either aligned in the machine direction 108 or canted and/or tilted relative thereto so that the disks or wheels raise the side panels and nip the fasteners together. Suitable wheel devices can, but need not, be timed elliptical wheels, and can comprise vacuum or traction surface wheels or the like. Still alternatively, the side panel transfer devices 430 can comprise 4-bar linkage mechanisms carrying a panel engagement head which contacts the back side panel 134 to raise the panel relative to the plane of the lower alignment conveyor 258. The rotary motion provided by the 4-bar linkage can allow the panel engagement head to raise a back side panel 134 relative to the lower alignment conveyor 258, with the back side panel being allowed to slip off the inward edge of the panel engagement head. A drive mechanism for the 4-bar linkage can be programmed to vary the angular velocity of the panel- engagement head such that its velocity in the machine direction 108 matches the speed of the back side panel 134 while the panel-engagement head is in contact with the back side panel. Alternatively, the angular velocity of the
panel-engagement head can be matched with the velocity of the side panel using a cam gearbox, non-circular gearing, or the like. Such devices could further comprise a feedback system to register the panel-engagement head to the back side panel 134. In yet another alternative embodiment, the side panel transfer devices 430 can comprise folding boards or folding skis to provide sequential or simultaneous inward and upward relative movement of the laterally outward portions of the back side panels 134 and the fastening components 82. Other suitable side panel positioning devices 330 and side panel transfer devices 430 are disclosed in co-assigned U.S. Application No. 10/010110, which was filed November 13, 2001 by Tomsovic et al . and titled "Fluid Flow Device and Method for Positioning Garment Side Panels, " the entire disclosure of which is incorporated herein by reference.
Now referring to Figs. 12, 13 and 17-21, each tensioning assembly 530 comprises a rectangular support plate 532 mounted on a respective side panel transfer device 430 by a suitable mounting member 534 (Fig. 17) and fasteners 536. The support plate 532 is oriented generally parallel to the pants transport plane defined by the upper and lower alignment conveyors 256, 258 (e.g., generally horizontal in the illustrated embodiment) . A leading edge 538 (Fig. 13) of the support plate 532 is disposed just downstream from the upstream end 442 of the transfer device 430 and terminates at a trailing edge 540 of the plate upstream of the downstream end 444 of the transfer device. As best seen in Fig. 17, the support plate 532 also extends laterally inward toward the machine center line above the transfer device 430 (and hence above the back side panel 134 supported thereby) to separate the fastening components 82, 84.
An elongate support bar 542 is connected to the upper surface of the support plate 532 as shown in Fig. 17, such as
by overlaying an inner edge margin thereof and being secured to the plate by welding or suitable fasteners (not shown) . The support bar 542 extends in the machine direction 108 downstream beyond the trailing edge 540 of the support plate to a downstream end 546 (Fig. 13) of the support bar disposed substantially downstream from the side panel transfer device 430. As best seen in Fig. 17 and 18, the support bar 542 is relatively narrow compared to the support plate 532 and has a generally C-shaped, or U-shaped cross-section along the portion of the support bar that extends downstream from the support plate. For example, the support bar 542 of the illustrated embodiment has a width of about .375 inches and a height of about .375 inches. It is understood, however, that the cross-section of the support bar 542 may be rectangular, circular, I-shaped, T-shaped or other suitable shape without departing from the scope of this invention. The support bar 542 is positioned higher than the lower alignment conveyor 258 for interposition between the front and back side panels 34, 134 upon movement of the training pants 102 in the machine direction 108 past the support bar. The support bar 542 is also positioned laterally between the lower alignment conveyor 258 and the side panel transfer device 430 for interposition between the absorbent chassis 32 and the engagement seam 88 following engagement between the fastening components 82, 84 as shown in Fig. 18 and later herein described.
With particular reference to Fig. 13, an elongate tensioning member 548 is mounted on the support bar 542 generally at the downstream end 546 thereof and has an upstream end 550 spaced longitudinally (e.g., in the machine direction) from the downstream end 444 of the side panel transfer device 430. More particularly, the tensioning member 548 comprises a top wall 552 having an inner edge
margin 554 (Fig. 20 which overlays the support bar and is secured thereto by suitable fasteners (not shown) . The top wall 552 of the tensioning member 548 extends laterally outward from the support bar 542 generally parallel to the pants transport plane defined by the upper and lower alignment conveyors 256, 258 (which in the illustrated embodiment is horizontal) .
A side wall 556 (Fig. 20) is secured to the outer edge of the top wall 552, such as by being formed integrally therewith, to define an upper corner 558 of the tensioning member 548 and depends from the top wall generally inward at an angle relative thereto. The cross-section of the tensioning member 548 is thus generally V-shaped, and is more particularly the shape of the numeral "7." As an example, the side wall 556 desirably forms an angle with the top wall 552 in the range of about 50° to about 65°, and more desirably about 60°. However, it is understood that the angle formed by the side wall 556 and the top wall 552 may be less than 50° or greater than 65° without departing from the scope of this invention. A bottom wall 560 is secured to the lower edge of the side wall 556, such as by being formed integrally therewith, to define a lower corner 562 of the tensioning member 548 and extends generally inward and up from the side wall toward the lower alignment conveyor 258. However, it is contemplated that the bottom wall 548 may be omitted without departing from the scope of this invention. As shown in Fig. 20, the upper and lower corners 558, 562 of the tensioning member 548 are desirably rounded to inhibit tearing of the front and back side panels 34, 134 as the side panels are conveyed over the tensioning member.
As best seen in Figs. 6, 12 and 13, the tensioning member 548 has a tapered lead portion 564 which gradually increases in cross-sectional dimension as the tensioning
member extends from its upstream end 550 where the cross- sectional dimension of the tensioning member corresponds generally to that of the support bar 542 to a main portion 566 of the tensioning member along which its cross-sectional dimension is generally uniform. As an example, the main portion 566 of the tensioning member 548 of the illustrated embodiment has a width of about 1.33 inches and a height of about 2.00 inches. As an additional example, the tensioning member 548 is approximately 15.25 inches in length, with the lead portion 564 being about 5.5 inches long and the main portion 566 being about 9.75 inches long.
The tensioning member 548 is desirably positioned vertically for interposition between the front and back side panels 34, 134 as the training pants 102 are conveyed in the machine direction 108 past the tensioning member. The lower corner 562 of the tensioning member 548 along the main portion 566 thereof is disposed substantially below the lower alignment conveyor 258 (and hence below the back waist region 24 of the absorbent chassis 32) . The tensioning member 548 is also positioned laterally outward from the lower alignment conveyor 258 for interposition between the absorbent chassis 32 and the engagement seam 88 defined by engagement between the fastening components 82, 84. It is contemplated that the vertical and/or lateral position of the tensioning member 548 relative to the lower alignment conveyor 258 may vary to adjust the amount of tensioning applied to the side panels 34, 134 as the side panels are conveyed over the tensioning member in the manner to be described. However, the lateral spacing of the tensioning member 548 from the lower alignment conveyor 258 is desirably sufficient to inhibit pinching or binding of the back side panel 134 therebetween.
The seaming section 250 also includes an air bar (broadly, a gas delivery device) , generally indicated at 570
(Figs. 6, 12 and 21), extending longitudinally in parallel spaced relationship with the main portion 566 of the tensioning member 548 at a position which is generally lower than and laterally outward of the lower corner 562 of the tensioning member. The air bar 570 comprises an elongate, cylindrical tube 572 in fluid communication with a source (not shown) of pressurized gas, such as air, for receiving pressurized air within an internal passage 574 (Fig. 21) of the tube. Exhaust openings 576 (one of which is shown in Fig. 21) are formed in the side wall of the tube 572 in longitudinally spaced relation with each other along the length of the tube. The exhaust openings are located on an upward and slightly inward facing portion of the side wall to direct pressurized air exhausted from the tube toward the side wall 556 of the tensioning member 548.
As an example, the air bar 570 of the illustrated embodiment has a length of about 9.75 inches, an internal diameter of about 0.5 inches and exhaust openings 576 each having a diameter of about 0.05 inches and spaced about one inch apart along the length of the air bar. Pressurized air received by the air bar 570 and exhausted therefrom toward the side wall 556 of the tensioning member 548 is desirably in the range of about 10 psi to about 40 psi. It is understood that the air bar 570 may be positioned other than below and outward of the lower corner 562 of the tensioning member 548, as long as pressurized air exhausted from the air bar is directed generally inward toward the side wall 556 of the tensioning member. It is also contemplated that the air bar 570 may be omitted without departing from the scope of this invention.
Now referring to Figs. 13 and 19, the seaming section 250 further comprises a pair of rollers 578 mounted for rotation on respective axles (one of which is shown in Fig.
12 and indicated at 579) . Each of the axles is supported by a lever arm 581 which is pivotably mounted on the lower alignment conveyor 258 immediately downstream of the side panel transfer devices 430, e.g., between the downstream ends 444 of the side panel transfer devices and the upstream ends 550 of the tensioning members 548. The rollers 578 are sized and positioned vertically for close contact relationship with the upper alignment conveyor 256 to define contact nips 580 (one of which is shown in Fig. 19) therebetween through which the engagement seams 88 pass following initial engagement of the respective fastening components 84, 82 of the side panels 34, 134. Each lever arm 581 is operatively connected to a respective suitable pneumatic device 583 which biases the roller 578 into contact with the upper alignment conveyor 258. As an example, the rollers 578 of the illustrated embodiment have an outer diameter of about three inches and a face (e.g., width) of about 2.75 inches.
The lever arm 581 supporting the roller 578 is pivotable to allow pivoting of the roller down away from the upper alignment conveyor as the side panels 34, 134 are conveyed through the contact nip 580. The pneumatic pressure which biases each roller 578 toward the upper alignment conveyor 258 is desirably sufficiently low to permit the side panels 34, 134 to urge the roller to pivot down away from the upper alignment conveyor upon passing through the contact nip 280, but sufficiently high to urge the fastening components 82, 84 together at the engagement seam 88. For example, the pneumatic pressure of the device 583 is such that the pressure of the roller 578 against the upper alignment conveyor 258 (and hence the fastening components 82, 84 as they pass therebetween) is in the range of about 1 to about 50 lbs, and more desirably in the range of about 5 to 20
pounds. It is understood, however, that the rollers 578 may be omitted altogether without departing from the scope of this invention. It is also contemplated that the rollers 578 may instead be maintained in spaced relationship with the upper alignment conveyor 258, such as in the range of about zero to about 5mm, to define the nips 280. A corresponding roller (not shown) is disposed within the upper alignment conveyor 258 in contact with the conveyor belt 266 and in opposed relationship with the rollers 578 to provide a corresponding bearing surface for the rollers 578.
In operation, the partially assembled and folded training pants 102 are received from the folding section 200 into the upstream end of the seaming section 250 generally in the configuration shown in Fig. 10, e.g., with the front waist region 24 of the absorbent chassis 32 folded over the back waist region 22 and the front and back side panels 34, 134 extending laterally out from the front and back waist regions. At the downstream location shown in Fig. 14, the front side panel 34 is drawn against the upper alignment conveyor 256 in an outstretched configuration, with the fastening component 84 of the front side panel facing up toward the upper alignment conveyor. An outer portion of the back side panel 134 is drawn through the slot 342 of the positioning device 330 'into the internal flow chamber 340 thereof.
Further downstream, such as the location illustrated in Fig. 15, the positioning device 340 has repositioned the back side panel 134 such that the fastening component 82 is laterally nearer the machine centerline. Vacuum is inhibited from drawing a laterally outward portion of the front side panel 34, including the fastening component 84, against the upper alignment conveyor, such as by closing off laterally outer holes 269 of the vacuum cover plate 264. As a result,
the laterally outward portion of the front side panel 34 tends to drop, due to gravity, away from the upper alignment conveyor 256 and folds over a folding finger 267. Alternatively, the upper alignment conveyor 256 can provide a uniform or nonuniform vacuum profile in the cross machine direction. In particular embodiments, the upper alignment conveyor 256 can draw a nonuniform vacuum in the cross- machine direction. Specifically, the upper alignment conveyor 256 can draw a concentrated vacuum at laterally outward regions as well as some area of vacuum in a central region disposed between the laterally outward regions. The laterally outward regions can be positioned such that they correspond to locations of the front side panels 34 immediately laterally inward from the locations of the fastening components 84. The concentrated vacuum adjacent the inside edge of the fastening components 84 can encourage the inside edge thereof to generally function as a hinge point for folding. The concentrated vacuum can be formed by a plurality of slots or an increase in the number of apertures in the vacuum cover plate 264, by separate vacuum chambers, or the like. The focused vacuum in the central region can reduce energy consumption and lessen draw of the back side panels 134 toward the upper alignment conveyor 256. Upon reaching the location shown in Fig. 16, the laterally outward portion of the front side panel 34 has been folded through approximately 180 degrees by a suitable panel folding device (not shown) such that the fastening component 84 of the front side panel is now facing down in generally opposed relationship with the fastening component 82 of the back side panel 134. The panel folding device (not shown) acts on the laterally outward portion of the front side panel 34 after the panel is folded down over the folding finger 267 and can comprise, for example, one or more air nozzles (not
shown) which blow the laterally outward portion of the front side panel 34, including the initially outward-facing fastening component 84, to a horizontal orientation directed toward the center line of the upper alignment conveyor 256. The panel folding device can operate on a continuous or timed intermittent basis, and can progressively fold the side panel 34 or fold the side panel as a single unit. The panel folding device can alternatively comprise other mechanisms for creating a suitable force to fold or assist to fold the front side panel 34. For example, the panel folding device can comprise folding boards or skis which fold the front side panel through 180 degrees; a helical surface that pushes the front side panel into the folded configuration; or the like. Once folded inward, the folded portion of the front side panel 34, including the fastening component 84, is drawn against the upper alignment conveyor to maintain the folded configuration of the front side panel.
The side panel transfer device 430 intersects the downstream end 336 of the positioning device 330 such that the portion of the back side panel corresponding to the fastening component 82 is supported by the side panel transfer device as the back side panel exits the positioning device. At this location, the fastening components 82, 84 are in opposed, vertically spaced relationship with each other. The side panel transfer device 430 elevates the fastening component 82 of the back side panel 134 generally in a "z-direction" perpendicular to the machine direction 108 while the remaining extent of the back side panel hangs generally limp between the lower alignment conveyor 258 and the transfer device. Further downstream, as shown in Fig.
17, the fastening component 82 of the back side panel 134 has been elevated further up toward the fastening component 84 of the front side panel 34. The support plate 532 of the
tensioning assembly 530 extends inward from the side panel transfer device 430 over the back side panel 134 to separate the fastening components 82, 84.
Upon reaching the downstream end 444 of the side panel transfer device 430 (Fig. 18) , the fastening component 82 of the back side panel 134 has been elevated into engagement with the fastening component 84 of the front side panel 34 to define the engagement seam 88. The engaged fastening components 82, 84 are urged together upon passing between the nip defined by the downstream end 444 of the transfer device 430 and the upper alignment conveyor 256 to facilitate further engagement between the fastening components as the training pants 102 are conveyed further downstream. The support bar 542 of the tensioning assembly 530 is interposed vertically between the front and back side panels 34, 134 and laterally between the lower alignment conveyor 258 and the engagement seam 88 upon fastening engagement between the fastening components 82, 84. The training pants 102 are then transported further downstream past the roller 578 whereby the engaged fastening components 82, 84 pass through the contact nip 580 between the roller and the upper alignment conveyor 256 as shown in Fig. 19 to further urge the fastening components together.
Downstream of the nip 580, the training pants 102 are transported past the upstream end 550 of the tensioning member 548. Figure 20 illustrates the side panels 34, 134 at a location along the tapered lead portion 564 of the tensioning member 548. At this location, the vacuum applied by the upper alignment conveyor 256 to the folded portion of the front side panel 34 is substantially reduced to release the fastening component 84 of the front side panel from being drawn toward the upper alignment conveyor. As a result, the fastening component 84 of the front side panel 34 hangs down
from the upper alignment conveyor 256 and supports the back side panel 134 in a generally limp configuration via engagement between the fastening components 82, 84. In the illustrated embodiment, the back side panel 134 contacts the bottom wall 560 and lower corner 562 of the tensioning member 548 and is positioned substantially below the lower alignment conveyor 256 and the back waist region 24 of the absorbent chassis 32. However, it is contemplated that the back side panel 134 may hang down below the tapered lead portion 564 of the tensioning member 548 at the location shown in Fig. 20. Finally, in accordance with one embodiment of a method for increasing engagement between fastening components 82, 84 of a pre-fastened garment, the engagement seam 88 is subjected to a shear stress to promote increased engagement between the fastening components while stretching fastening components or at least maintaining the fastening components in a generally relaxed condition (e.g. as the shear stress is being generated at the engagement seam) . The term relaxed, as used in this context, is intended to mean that the fastening component does not elastically deform such as by stretching or contracting (e.g., increasing or decreasing in size) relative to the condition of the fastening components at the time of engagement therebetween. The fastening components may be in tension and still be in a relaxed condition as that term is used herein. In other words, the fastening components 82, 84 are urged to slide (including stretch) relative to each other at the engagement seam 88. In the illustrated embodiment, the shear stress is generated upon conveyance of the training pants 102 downstream over the main portion 566 of the tensioning member 548 as shown in Fig. 21. Based on the vertical and lateral positioning of the tensioning member 548 relative to the upper and lower alignment conveyors 256, 258 (and hence the absorbent chassis
32) , as well as the orientation and cross-sectional dimensions of the main portion 566 of the tensioning member, the front and back side panels 34, 134 contact the tensioning member and are generally expanded outward, such as laterally and/or vertically, relative to the absorbent chassis and pulled taut around the tensioning member.
More particularly, the front side panel 34 extends laterally out over the top wall 552 of the tensioning member 548 and folds down over the upper corner 558 such that the fastening component 84 of the front side panel (and hence the engagement seam 88) generally overlays a portion of the angled side wall 556 of the tensioning member. The back side panel 134 extends down below the bottom wall 560 of the tensioning member 548 and folds up over the lower corner 562 thereof. Tensioning the side panels 34, 134 in this manner orients the engaged fastening components in generally opposed relationship with the side wall 556, and more particularly such tensioning urges the fastening components to generally lie flat against the angled side wall whereby the side wall broadly defines a flat bearing surface against which the fastening components lay flat . Air exhausted from the air bar 570 is directed to impact the fastening components 82, 84 at the engagement seam 88 to urge the components inward against the side wall 556 to further urge the components together.
Tensioning the side panels 34, 134 also pulls the engaged fastening components 82, 84 in opposite directions, e.g., by applying a pulling force to the fastening component 84 of the front side panel 34 generally upward along the side wall 556 and applying an opposite pulling force to the fastening component of the back side panel 134 generally downward along the side wall as indicated by the directional arrows in Fig. 21. As a result, the fastening components 82,
84 are urged to slide relative to each other. The tensioning thus generates a shear stress at the engagement seam 88 to promote increased engagement between the fastening components 82, 84. For example, where the fastening components 82, 84 are hook and loop fasteners, generating a shear stress at the engagement seam 88 urges sliding movement of one fastening component relative to the other such that the hooks become further embedded or otherwise entangled in the loops, thereby strengthening the engagement between the fastening components . Where the base material of the loop fastener is constructed of an elastic material, the applied shear stress may alternatively, or may additionally, result in stretching (which is also broadly considered herein as a sliding movement) of the loop fastener relative to the hook fastener while the shear stress is generated at the engagement seam, thereby increasing the size of the loop fastener and hence the spacing between adjacent loops to allow the hooks to embed deeper therein. Friction between the side panels 34, 134 and the tensioning member 548 as the panels are conveyed over the tensioning member subjects the fastening components 82, 84 to a shear stress generally along the engagement seam 88, e.g., in the machine direction 108.
Fig. 22 is a cross-section of a seaming section of a second embodiment of apparatus of the present invention. The seaming section of this second embodiment is similar to that of the first embodiment with the exception that the tensioning assembly 630 further comprises an air bar, generally indicated at 670, positioned below and laterally inward of the bottom wall 660 of the tensioning member 648. Exhaust openings 676 (one of which is shown in Fig. 22) of the air bar 670 are positioned so as to direct pressurized air exhausted therefrom to impact the portion of the back
side panel 134 extending between the back waist region 24 of the absorbent chassis 32 and the bottom wall 660 of the tensioning member 648. The pressurized air urges the back side panel 134 to become taut around the bottom wall 660 and lower corner 662 of the tensioning member 648. As a result, the front side panel 34 is pulled taut against the top wall 652 and upper corner 658 of the tensioning member 648 to thereby generate a shear stress at the engagement seam 88. It is contemplated that the air pressure of air exhausted from the air bar 670 may be selectively adjusted to control the tension in the side panels 34, 134.
While the tensioning member 548, 648 of the illustrated embodiment has a cross-section generally in the shape of the numeral "7" so that the engagement seam 88 lays against a flat surface (e.g., the side wall 556, 656) upon tensioning of the front and back side panels 34, 134, it is contemplated that the tensioning member may have a cross-section of generally any shape, such as circular (e.g., such as by using a roller), semi-circular, polygonal, U-shaped, C-shaped or any other suitable shape. The tensioning member 548, 648 may also be oriented vertically (e.g., normal to the machine direction) instead of longitudinally. Also, the fastening components 82, 84 need not lie against the tensioning member 548, 648 or other flat surface upon tensioning of the front and back side panels 34, 134, but may instead remain free from contact with any structure without departing from the scope of this invention. Moreover, the length of the tensioning member 548, 648 over which the engagement seam 88 is conveyed may be substantially shorter than the length of the engagement seam so that only a portion of the engagement seam is conveyed over the tensioning member at any given time. In this manner, the fastening components 82, 84 would tend to bend, or flex at the engagement seam 88 as the
fastening components are conveyed over the tensioning member 548, 648 to further work the fastening components together. It is also understood that the shear stress applied to the engagement seam 88 may alternatively, or may additionally, be generated in the machine direction (e.g., longitudinally) in which the training pants are transported through the seaming section, such as by applying a longitudinally oriented force (e.g., pulling, friction, etc.) to one of the fastening components 82, 84, or by applying longitudinally opposite forces to the fastening components.
It also contemplated that a shear stress may alternatively, or may additionally, be generated at the engagement seam 88 other than by the seaming section 250. For example, from the seaming section 250, the pre-fastened training pants 20 can be processed through various finishing stations 254 for operations such as side panel tucking, packaging, and the like, during which a shear stress may be applied to the engagement seam 88. Fig. 23 schematically illustrates another embodiment of a tensioning assembly in the form of a side panel tucking station, generally indicated at 730, downstream of the upper and lower alignment conveyors 256, 258 of the seaming section 250. The tucking station 730 comprises opposed upper and lower vacuum conveyors 732, 734 having an upstream end 736 generally aligned with the upper and lower alignment conveyors 256, 258 of the seaming section 250 for receiving the pre-fastened training pants 20 into the tucking station.
In the illustrated embodiment, the upper and lower vacuum conveyors 732, 734 are generally angled relative to the upper and lower alignment conveyors 256, 268 of the seaming section 250 for conveying the side panels from a downstream end 738 of the tucking station to subsequent processing apparatus (not shown) . The vacuum conveyors 732,
734 are also angled relative to each other such that the spacing between the upper and lower vacuum conveyors at the upstream end 736 of the tucking station 730 is substantially greater than the spacing therebetween at the downstream end 738 of the tucking station.
A blade assembly, generally indicated at 740, is mounted on the upper vacuum conveyor 732 intermediate the upstream and downstream ends 736, 738 of the tucking station 730. As shown in Fig. 23, the blade assembly comprises of drive shafts (one of which is shown in Fig. 12) 742 spaced laterally outward from opposite sides of the upper and lower vacuum conveyors 732, 734. The drive shafts 742 are operatively connected to a suitable motor (not shown) for driven rotation about respective axes extending generally normal to the lower vacuum conveyor 732. Three blades 744
(two of which are shown in Fig. 23) are secured to each drive shaft 742 and extend outward from the drive shaft transverse to the rotation axis thereof for conjoint rotation with the drive shaft relative to the upper and lower vacuum conveyors 732, 734. As shown in Fig. 24, the blades 744 are positioned and sized to extend transversely between the upper and lower vacuum conveyors 732, 734 for contacting the engaged front and back side panels 34, 134 of the training pants upon rotation of blades, and are more desirably positioned and sized in length such that upon rotation between the upper and lower vacuum conveyors, each blade is capable of extending substantially laterally inward of the side edges 36 of the absorbent chassis 32 of the training pants 20.
In operation, the pre-fastened training pants 20 are received between the upper and lower vacuum conveyors 732,
734 at the upstream end 736 of the tucking station 730. The front waist region 22 of the absorbent chassis 32 is drawn and held against the upper vacuum conveyor 732 and the back
waist region 24 is drawn and held against the lower vacuum conveyor 734. The spacing between the conveyors 732, 734 at the upstream end 736 of the tucking station 730 pulls the front and back waist regions 22, 24 apart, thereby generally straightening the engaged front and back side panels 34, 134 (e.g., orienting the side panels more vertically) for exposure to the blades 744. As the training pants 20 are conveyed past the blade assembly 740 as shown in Fig. 24, the blades 744 rotate on the rotation axis of the drive shafts 742 into contact with the side panels (e.g., the back side panels 134 in the illustrated embodiment) to urge the engaged side panels 34, 134 laterally inward between the front and back waist regions 22, 24 of the training pants 20 to a tucked configuration. The positioning and length of the blades is such that the front and back side panels 34, 134 are pulled taut as shown in Fig. 24 upon being tucked between the front and back waist regions 22, 24 of the training pants 20. As a result, oppositely directed pulling forces, as indicated by direction arrows, are applied to the fastening components 82, 84 to generate shear stresses at the engagement seams 88. It is contemplated that the blades 744 on each side of tucking station 730 may instead contact the front side panels 34, or the blades on one side of the tucking station may contact the respective back side panel 134 and the blades on the opposite side of the tucking station may contact the respective front side panel 134, without departing from the scope of this invention.
Figs. 27 and 28 illustrate another method of manufacturing the training pants 20 to generate a shear stress at the engagement seam 88 formed by the fastening components 82, 84, and more particularly to generate a shear stress by effecting a sliding movement of one fastening
component relative to the other fastening component at the engagement seam. As illustrated schematically in Fig. 27, a continuous web of partially assembled pants 102 is formed in an unfolded configuration at an assembly section 1200, such as the assembly section 100 of Fig. 4. The assembly section 1200 can include a cutting mechanism (not shown) which selectively cuts the web into discrete, partially assembled training pants 102. The partially assembled pants 102 can then be folded at a folding section 1202 about a fold line generally bisecting the pants. As such, the waist regions 22 and 24 of each training pant can be positioned in facing relationship with the side panels 34 and 134 extending laterally outward relative to the longitudinal axis 48 of the training pants. For example, the fold line can extend in a lateral direction through the crotch region 26 of the training pants. Desirably, the discrete training pants 102 are consistently folded about the fold line such that the front and back waist edges 38 and 39 of the training pants align with each other. As an example, the folding section 1202 can be substantially the same as the folding section 200 of Fig. 5. Other suitable devices for folding the side panels 34 and 134 parallel to the longitudinal centerline of the pants can include folding boards, folding skis, paddles, fingers, vacuum devices, air blasts, mechanical devices with reciprocating motion such as tuckers, four-bar linkages, slide-crank mechanisms, or the like and combinations thereof which are desirably adapted to stretch or extend the fastening component, e.g., fastening component 84, formed of loop material prior to its engagement with the cooperating fastening component, e.g., fastening component 82, formed of hook material .
Upon folding the pants 102, the opposed side panels 34 and 134 are desirably in at least partially opposed relationship with each other so that at least portions of the fastening components 82, 84 overlap one another. The side panels 34 and 134 can alternatively be folded together in conjunction with engagement of the fastening components 82, 84 in a seaming section 1204, such as the seaming section 250 described previously. The seaming section 1204 forms the engagement seams 88 of the pants 20. The training pants 20 can be subjected to an activation station 206, which can be positioned downstream of or otherwise form part of the seaming section 1204. The activation station 206 can comprise an activation source such as a heating unit to initiate retraction of the retractive material in those pants constructions which use a heat activated retractive material in any components of the pants 20, including the fastening component 84 formed of a retractive loop-type fastening material as described previously. It is contemplated that materials which shrink or contract through other activation means can also be utilized in the present invention, such as disclosed in United States Patent No. 4,883,549, incorporated herein by reference, or simply by slow responding material. The activation station 206 can comprise a separate stage of the manufacturing operation or can be incorporated into another stage. In particular embodiments, the activation station 206 can be combined with devices such as product stackers for packaging the pants 20. Suitable devices incorporating activation mechanisms are disclosed in U.S. Patents 4,640,726 issued February 3, 1987 to Sallee et al . and 4,663,106 issued May 5, 1987 to Pomplun et al . , which are incorporated herein by reference .
In one embodiment, at least a portion of the retractive material is activated and caused to retract subsequent to engagement of the fastening components 82, 84. In other words, the fastening components 82, 84 are engaged while both components are in a generally relaxed state (e.g., neither component is increasing or decreasing in size at the time of engagement) . The retractive material, such as the loop-type material of the fastening component 84, is activated to retract relative to the other fastening component 82 whereby retraction of the fastening component 84 urges sliding movement of the fastening component 84 relative to the fastening component 82 to promote increased engagement between the fastening components at the engagement seam 88. While the loop-type fastening material was described in particular embodiments as comprising a retractive material, other components of the training pants 20 such as distinct elements or portions of the outer cover, bodyside liner, absorbent assembly, waist elastics, side panels or fastening components can alternatively or additionally comprise retractive materials.
Figure 7 illustrates training pants 1300 at three stages during manufacture, denoted with reference numerals 1301, 1302 and 1303. The training pants 1300 are similar to the training pants 20 shown in Figure 1, although the front side panels 34 are narrower than the back side panels 134. The training pants 1300 at stage 1301 has been folded through the crotch region 26 to overlap the waist regions 22 and 24 and the hip regions. At stage 1302, one or both pairs of side panels 34 and 134 of the training pants 1300 can be folded along fold lines 1306 which are parallel to the longitudinal centerline 1308 of the training pants. With the fastening components 82, 84 engaged, the waist regions 22 and 24 define the waistband 75 and hip section 77, both of which encircle
the pants 1300 between the crotch region 26 and the waist opening. The waistband 75 is contiguous with the waist opening 50 (Figure 1) while the hip section 77 is disposed between the waistband and the leg openings 52 (Figure 1) . At stage 1303, the retractive materials forming the waist elastic members 54 and 56, the side panels 34 and 134, and/or other components, such as loop-type fastening material, can be activated and the retractive materials allowed to retract. If the training pants 20, or other garment formed in accordance with the present invention, is manually formed into a three dimensional garment to fit a wearer, the fastening components 82 (e.g., formed from the loop-type material) and rear side panels 134 are stretched toward the front side panels 34 and then applied to the respective hook material 84 on the front side panels 34 to form the engagement seams 88. The loop material and side panels 134 are then released and allowed to contract on the hook material (e.g., to slide relative to the hook material) to produce an engagement seam which exhibits greater engagement strength than conventional mechanical fastening systems.
Alternatively, it is contemplated that the loop material can be stretched or otherwise extended and the hook material applied to it by any suitable means for causing engagement between the hook and loop material while the loop material is in an extended or stretched state and then allowed to retract .
As discussed above, it is also contemplated that when the training pants 20 or the like garment are being initially constructed and folded mechanically, such as by the apparatus of the. present invention, the loop material and/or its underlying support material of the various embodiments described above can be extended and placed in engagement with the hook material and then pressed thereon to give an initial
construction that is stronger in the mechanical fastener system than conventional mechanical fastening systems. Also as mentioned above, in an alternative embodiment where the garment is constructed and assembled by machine the loop material may be a retractive material that is simply placed on the hook material during making of the garment and then the hook material can be shrunk by an application of heat to embed the hooks into the loop material . Alternatively, as mentioned above, the loop material can retract in other ways, such as temporarily inhibiting retraction of a stretched elastic member as described in United States Patent No. 4,883,549, or other means such as light motion, pressure exerted, etc.
It is believed that the stretch in the loop material increases the amount of engagement between the fastening components 82, 84 at the engagement seam, reducing the occurrence of "pop opens" (refastenable side panels with hook-and-loop disengaging) over conventional hook-and-loop fasteners . It is believed that a wide range of hook-and-loop materials would be suitable for use in the present invention, so long as the loop material is sufficiently stretchable or retractable to exhibit the desired enhanced engagement capabilities that produce the desired reduction in "pop opens" over conventional hook-and-loop fasteners. For example, in the embodiment of Figures 3 and 4, it is desirable that the loop material exhibit a high stretchability of approximately 150 to 300 percent although greater stretchability such as from 300 to 450 percent of at least the loop material, can be exhibited by the material. In its preferred form it is desirable that the loop material be constructed of an extensible material such as but not limited to a stretch bonded material .
It will be appreciated that details of the foregoing embodiments, given for purposes of illustration, are not to be construed as limiting the scope of this invention. Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. For example, features described in relation to one embodiment may be incorporated into any other embodiment of the invention. Accordingly, all such modifications are intended to be included within the scope of this invention, which is defined in the following claims and all equivalents thereto. Further, it is recognized that many embodiments may be conceived that do not achieve all of the advantages of some embodiments, particularly of the preferred embodiments, yet the absence of a particular advantage shall not be construed to necessarily mean that such an embodiment is outside the scope of the present invention. When introducing elements of ■ the present invention or the preferred embodiment (s) thereof, the articles "a", "an", "the" and "said" are intended to mean that there are one or more of the elements. The terms "comprising", "including" and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements. As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.