US20130211365A1 - Disposable Undergarment and Related Manufacturing Equipment and Processes - Google Patents

Abstract

This invention pertains to a three dimensional disposable panty, subassemblies of the panty, and an apparatus and methods for making the panty and subassemblies. The panty is designed to hold a primary absorbent sanitary pad. The panty may have elasticized leg and waist openings and be stretchable about the hip and stomach regions of a user. the panty provides backup protection to control egress of fluids that leak or seep around or through the primary sanitary pad. The panty includes a secondary absorbent positioned in the crotch area and extending into the body of the disposable panty, front and back, and preferably over the leg elastics to trap, inside the panty, leakage from the primary absorbent, and to prevent strike through onto e.g. outer clothing and bed linen. The apparatus and methods facilitate assembling leg elastics and crotch elastics into the panty subassemblies while assembling a series of panty subassemblies in a continuous web structure at a constant, or relatively constant, continuous and efficient speed.

Description

RELATED APPLICATIONS
• The present application is a divisional application of Ser. No. 12/913,362, filed Oct. 27, 2010, which is a continuation application of and claims priority to U.S. patent application Ser. No. 11/240,262, filed Sep. 30, 2005, now abandoned, which is a continuation-in-part application of U.S. patent application Ser. No. 09/548,231, filed Apr. 12, 2000, now abandoned, which is a continuation of prior U.S. patent application Ser. No. 08/937,225, filed Sep. 11, 1997, now U.S. Pat. No. 6,049,916, which is a divisional of prior U.S. patent application Ser. No. 08/382,108 filed on Jan. 31, 1995, now U.S. Pat. No. 5,745,922, each of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
• Undergarments are made typically of cotton and/or synthetic materials. The cotton and synthetic panties typically do not offer barrier protection. Often the synthetic undergarments have a cotton lined crotch to absorb vaginal discharges or perspiration. The absorbent/barrier properties of regular undergarments are minimal such that any vaginal discharge and/or heavy perspiration may strike through onto outer clothing; i.e., liquid penetrates from the interior to the exterior of the panty.
• Panty liners and feminine care sanitary napkins or pads used with regular undergarments have polyethylene backings that provide some barrier properties inhibiting liquid strike through. However, if the vaginal discharge extends to the sides or the ends of the pads, the discharge can leak or seep around an edge of the pad and onto the undergarment. Such leakage can stain the undergarment. Depending upon the amount of leakage, liquid may strike through or go around the undergarment and stain outer clothing and/or bedding. Women with heavy liquid flows may often use one or more maxi pads, double pads and/or tampons alone, or in combination, and change these pads and tampons frequently to prevent embarrassing, messy leakage around the edges of the pads and/or staining of outer clothing. In some cases, during their heaviest flow days, some women will restrict their activities and stay home.
• Many women experience some leakage of menses from their pads to their undergarments. This varies from being limited to a small number of pads leaking onto only the undergarment during light flow to more prevalent leakage onto the wearer's outer clothing on pads worn during heavy flow. Normally this leakage occurs at the side of the pad, although end leakage is also a problem. Placement of maxi pads and overnight pads in the crotch of regular undergarments shows that, at best, the pads lay on the leg elastic and, at worst, overhang the leg elastics. This causes side leakage onto the undergarment and possibly onto outer clothing. Typical leakage from the pads is caused by poor fit of the pad to the body, improper positioning of the pad by the user and lack of absorbency. Leakage from the undergarment onto the outer clothing is typically due to incompatibility between the pad width and the panty crotch width and/or lack of barrier properties in the panty material around the edge portion of the pad.
BRIEF SUMMARY OF THE INVENTION
• The present invention broadly includes a three dimensional, disposable, discrete panty, subassemblies of the panty, and apparatus and methods for making the panty.
• In one aspect of the invention, a method for attaching elastic to a crotch area of an undergarment includes the steps of cutting an elastic thread into a plurality of elastic sections; providing a secondary absorbent for receipt of at least one of the elastic sections, the secondary absorbent defining an inner side and an opposing outer side; attaching the elastic sections to the inner side of the secondary absorbent as the elastic sections and the secondary absorbent move in a machine direction; maneuvering the secondary absorbent with the elastic sections attached thereto to a non-machine direction; and attaching the secondary absorbent to a garment web moving in the machine direction, the elastic sections of the inner side disposed against an inner crotch portion of the garment web, the opposing outer side visible in the crotch portion. In this aspect, each elastic section is from about one inch to about three inches in length. Also in this aspect, the elastic sections are attached to the inner side of the secondary absorbent by an adhesive.
• According to a further aspect of the invention, a disposable garment assembly includes a disposable garment defining a length and a width and including an outer cover having a front body portion and a back body portion, the front body portion and the back body portion being connected by a crotch portion, the outer cover, when laid out flat, having a length and a width, the front body portion and the back body portion being connected together to form a waist opening, a first leg opening and a second leg opening, the first and second leg openings having respective first and second front and back leg edge portions and corresponding first and second side leg edge portions connecting the front and back leg edge portions, the outer cover comprising a first layer, and a second layer having a front portion and a back portion, the second layer front portion disposed adjacent the front body portion of the outer cover, the second layer back portion disposed adjacent the back body portion of the outer cover; a first absorbent defining a length and a width, each respectively less than the length and the width of the disposable garment, the first absorbent further including a liquid impermeable outer sheet and a liquid permeable inner sheet, the liquid impermeable outer sheet having a front portion and a back portion, and a center portion therebetween, each of the liquid impermeable outer sheet front and back portions of the first absorbent disposed adjacent one of the respective second layer front and back body portions of the outer cover, the first absorbent having a first absorbent capacity; a second absorbent including a first side and a second side and having a second absorbent capacity, the second absorbent attached in the crotch portion and covering the width of the first absorbent, the second absorbent underlying the first absorbent on the liquid impermeable outer sheet of the first absorbent, the first side of the second absorbent disposed facing the liquid impermeable outer sheet, the first absorbent capacity of the first absorbent being greater than the second absorbent capacity of the second absorbent; and a plurality of crotch elastics extendably affixed between the outer cover and the second side of the second absorbent proximate the crotch portion, the second absorbent affixed to the outer cover.
• In this aspect of the invention, the second absorbent capacity of the second absorbent is about one-half the absorbent capacity of the first absorbent. For instance, the second absorbent capacity of the second absorbent can be about 3 grams to about 6 grams, more particularly, about 4 grams to about 6 grams. Also in this aspect of the invention, the second absorbent is a stain shield.
• In a further aspect of the invention, a disposable garment has a length and a width, and includes an outer cover having front and back body portions connected by a crotch portion, the outer cover, when laid out flat, having a length between first and second ends and a width between first and second sides, the front and back body portions being connected together to form a waist opening and first and second leg opening. The outer cover in this aspect includes a first layer; a second layer having front and back body portions overlying respective front and back body portions of the outer cover; and a stain shield incorporated into the disposable garment, the stain shield having a length and a width and a garment facing side, the garment facing side having a front portion, a back portion and a center portion therebetween, the garment facing side of the center portion having a plurality of extensible crotch elastic pieces attached thereto proximate the crotch portion, the extensible crotch elastic pieces being disposed between the garment facing side and the outer cover of the crotch portion, the stain shield affixed to the outer cover, each of the garment facing side front and back portions of the stain shield disposed adjacent one of the respective second layer front and back portions, at least a portion of the stain shield having an overall total absorbent capacity of about 3 grams to about 6 grams. Also in this aspect, at least a portion of the absorbent has an overall total absorbent capacity of about 4 grams to about 6 grams.
BRIEF DESCRIPTION OF THE DRAWINGS
• The present invention will be more fully understood and further advantages will become apparent when reference is made to the following detailed description of the invention and the drawings, in which:
• FIG. 1 is a plan view of a garment subassembly according to an aspect of the invention;
• FIG. 2 is a plan view of the garment subassembly ofFIG. 1, including a secondary absorbent in the crotch;
• FIG. 3 is a cross section of the garment subassembly taken along line3-3 ofFIG. 2;
• FIG. 4 is a cross section of the garment subassembly taken along line4-4 ofFIG. 2;
• FIG. 5 is a perspective view of a disposable panty according to another aspect of the invention;
• FIGS. 6 and 7 are enlarged cut-away views of a fragment of the subassembly ofFIG. 1, particularly showing cross-crotch elastics in detail;
• FIG. 8 is a side elevation view of an equipment layout for fabricating and processing subassemblies according to another aspect of the invention;
• FIGS. 9 and 10 are pictorial views of a nip area of the elevation shown inFIG. 8;
• FIG. 11 is a plan view showing transverse positioning of front and back leg elastics along an advancing web as an outer cover layer and a body side layer are being joined according to an aspect of the invention;
• FIG. 12 is a plan view as inFIG. 10, showing an alternate pattern for elastic threads; and
• FIG. 13 is a perspective view showing steps in a method for cutting a plurality of elastics and attaching the elastics to a secondary absorbent according to another aspect of the invention.
DETAILED DESCRIPTION OF THE INVENTION
• The following detailed description is made in the context of an article including a disposable panty, and corresponding panty subassemblies, for holding a sanitary pad in place as a primary absorbent during use of the panty. It is readily apparent, however, that the present invention can be employed with other disposable sanitary articles, such as feminine tampons, incontinent garments and the like.
• The panty subassembly10 ofFIG. 1 illustrates an embodiment of a two-layer panty subassembly prior to incorporation of the secondary absorbent. The panty subassembly ofFIG. 2 illustrates the finished panty including all elements, but before the final steps of assembling the composite to form the panty structure.FIG. 5 shows the finally-assembled disposable panty structure.
• Referring toFIGS. 1-3, the panty subassembly10 has anouter cover layer12 generally defining the overall length “L1” and width “W1” of the subassembly, and abody side layer14 secured to the outer cover layer. The panty subassembly10 generally includes afront body portion16 terminating at afront waist portion18 as a first edge of the subassembly, aback body portion20 terminating at aback waist portion22 as a second edge of the subassembly, and acrotch portion24.
• Thebody side layer14 includes afront layer element19 generally overlying and secured to theouter cover layer12 on thefront body portion16, and aback layer element21 generally overlying and secured to theouter cover layer12 on theback body portion20. Aspace23 separates thefront layer element19 from theback layer element21.
• Referring toFIGS. 2 and 5, for assembling the subassembly ofFIG. 2 to form apanty25 as inFIG. 5, afirst side edge26 offront body portion16 is assembled with afirst side edge28 of theback body portion20 to form afirst side seal30. Similarly, asecond side edge32 of thefront body portion16 is assembled with asecond side edge34 of theback body portion20 to form asecond side seal36. Thewaist portions18,22 when assembled form a waist opening38 for putting on and taking off thepanty25. Thewaist opening38 is surrounded at least in part by a waist elastic40. The waist elastic40 is stretched and attached to thewaist portions18,22 in the stretched state. The waist elastic40 is released after attachment to produce waist folds orpleats42 to allow expansion of thewaist opening38 so that thepanty25 can fit various sizes of people. Because users of this invention generally prefer a brief style panty, thefront waist portion18 preferably comes as high as the navel and is level around the wearer's waist. Having the panty at this height provides a snug fit. Alternative panty styles include bikini (e.g. regular leg cut or french leg cut) and hipster (e.g. regular leg cut or french leg cut).
• Referring toFIGS. 1 and 5, thefront body portion16, theback body portion20, and thecrotch portion24, in combination, form left andright leg openings44 and46, respectively, which are generally circular or oval in shape in the finally assembledpanty25. Theleg openings44 and46 are formed by cutting away portions of theouter cover layer12, and corresponding portions if any ofbody side layer14. Eachleg opening44,46 is surrounded at least in part by a back leg elastic48, a front leg elastic50, and a crotch elastic51 between the back leg elastic and the front leg elastic. Each of the respective elastics48,50,51 is adjacent the respective one of theedges52 of the corresponding leg openings. The front and back leg elastics48,50 are secured between theouter cover layer12 and thebody side layer14 by adhesive55. The crotch elastics51 are secured betweenouter cover layer12 and a crotchelastic support sheet53, also by adhesive55. The elastics48,50,51 are in the stretched state when secured to theouter cover layer12. Accordingly, when the elastics, the outer cover layer, the body side layer, and thesupport sheet53, are released after the elastics are secured to the outer cover layer, the elastics produce leg folds or pleats54 at the edges of theleg openings44,46 to allow expansion of theleg openings44,46 to fit various sizes of legs.
• Thefront body portion16 may be divided into a frontupper portion56 and a frontlower portion58. Similarly, theback body portion20 may be divided into a backupper portion60 and a backlower portion62. Theupper portions56 and60 are preferably designed to include body elastics64 which readily stretch to allow the wearer to put on thepanty25 and then readily contract to resume the normal release state of the body elastics. This ensures a close or snug fit to different body sizes and forms. A number of body elastics64 are positioned on both the front and theback portions56,60, respectively, at positions between thewaist opening38 and theleg openings44,46, so that thepanty25 has a good fit, particularly around the body.
• Thelower body portions58,62 generally do not require the spaced elastics as in theupper body portions56,60, although the elastic threads may be used.
• The width of thecrotch portion24 between the left and right crotch elastics51 should be wide enough to accommodate laying the primary absorbent66 between theedges52 without having the primary absorbent66 obstruct the crotch elastics51. This allows the crotch elastics51 to contract and draw up the sides of the crotch about the primary absorbent, to thus accommodate the thickness of the primary absorbent66, and to give surface area within thecrotch portion24 of the panty,adjacent edges52, to contain leakage from the primary absorbent66.
• The width of thecrotch portion24 between the elastics51 should not be so wide as to seem bulky or uncomfortable. A suitable width is at least about 2.75 inches (70 mm) between the crotch elastics. Width ofcrotch portion24 is advantageous from about 3 inches (76 mm) to about 3.5 inches (89 mm). Preferably, the width is about 3 inches (76 mm).
• Preferably, the crotch elastics51 are from about 0.375 inch (10 mm) to about 0.625 inch (16 mm) wide. More preferably, the width is about 0.5 inch (13 mm). Preferably, ruffle material on the edge of theleg openings44,46 outside the leg and crotch elastics48,50,51 is less than about 0.25 (6 mm). More preferably, the ruffle material is less than about 0.125 inch (3 mm). It is most desirable to eliminate any ruffle material from the edges of theleg openings44,46.
• The overall width of thecrotch portion24 includes the width between the left and right crotch elastics51, the width of the crotch elastics, and any ruffle material outside the crotch elastics to theedges52 of the leg openings. Preferably, the overall width of thecrotch portion24 should be at least about 4 inches (102 mm).
• FIG. 2 shows the panty subassembly10 ofFIG. 1 with asecondary absorbent68 secured in thecrotch portion24, over theouter cover layer12 and parts of the front and backlayer elements19,21 of thebody side layer14. The width of thesecondary absorbent68 is sized in relation to the width of thecrotch portion24. Preferably, the width of thesecondary absorbent68 is at least the width of thecrotch portion24 between the crotch elastics51. More preferably, the width of the secondary absorbent is equivalent to the overall width of thecrotch portion24.
• Thesecondary absorbent68 should have sufficient capacity to absorb any flow or seepage of body fluid around or through the primary absorbent66. Thesecondary absorbent68 should preferably have a capacity and thickness substantially less than that of the primary absorbent66, thus providing a nonbulky and flexible fit. Thesecondary absorbent68 should have a total capacity of about one-half the capacity of the primary absorbent66. Preferably, thesecondary absorbent68 should have a total capacity of at least about 3 grams and not more than 6 grams. More preferably, the total capacity of thesecondary absorbent68 should be from about 4 grams to about 6 grams. However, the basis weight of, or the type of, thesecondary absorbent68 should be selected to provide resistance to flexibility of less than around 400 grams, as measured by INDA Standard Test method IST 90.3-92 Standard Test Method for Handle-O-Meter Stiffness of Nonwoven Fabrics.
• The secondary absorbent has a low stiffness. The low stiffness allows the absorbent and its barrier to remain attached to the conformableouter cover layer12 and thebody side layer14 which conform to a wide range of body sizes and shapes. Preferably, the secondary absorbent has a stiffness of less than 400 grams along any axis tested, more preferably less than 300 grams along any axis and less than 100 grams along the axis parallel to the waist opening. The secondary absorbent alone will have a stiffness of less than 250 grams and preferably less than 100 grams along any axis and more preferably less than 75 grams along the axis parallel to the waist opening.
• The overall length of thesecondary absorbent68 should be adequate to extend beyond the ends of the primary absorbent66, in order to be properly positioned to receive liquid which flows or seeps around the edges of the primary absorbent66. This overall length is typically at least about 15 inches (382 mm) thus extending beyond thecrotch portion24 along the longitudinal centerline A-A of the subassembly10. The length should be in the range of about 15 inches (382 mm) to about 19 inches (484 mm). Preferably, the length of thesecondary absorbent68 is about 17 inches (433 mm).
• The width of thesecondary absorbent68 beyond thecrotch portion24 should be at least as wide as the width of thecrotch portion24. The width of thesecondary absorbent68 may be narrowed beyond thecrotch portion24 but may thus compromise the containment of liquid flowing or seeping from the primary absorbent. More preferably, the width outside the crotch portion is wider than in the crotch portion, and is from about 5 inches (127 mm) to about 12 inches (306 mm), alternatively from about 5.5 inches (140 mm) to about 7.5 inches (191 mm). Preferably, the width is about 6.5 inches (165 mm).
• Referring toFIGS. 2,3, and4, the waist elastics40, the body elastics64, and the leg elastics48,50,51 are generally covered by the front and backlayer elements19,21 of thebody side layer14.
• Bothouter cover layer12 andbody side layer14 are compliant and soft feeling to the wearer. The following description of materials from which theouter cover layer12 can be made applies equally to the material of thebody side layer14.
• Theouter cover layer12 may be liquid pervious, permitting liquids to readily penetrate into its thickness, or impervious, resistant to the penetration of liquids into its thickness.Outer cover layer12 may be made from a wide range of materials, such as natural fibers (e.g. wood or cotton fibers), synthetic fibers (e.g. polyester or polypropylene fibers) or from a combination of natural and synthetic fibers or reticulated foams and apertured plastic films. Theouter cover layer12 may be woven, nonwoven such as spunbonded, carded, or the like. A suitableouter cover layer12 is carded, and thermally bonded by means well known to those skilled in the fabric art. Alternatively, theouter cover layer12 is derived from a spunbonded web. In preferred embodiments, the outer cover layer is spunbonded polypropylene nonwoven with a wireweave bond pattern having a grab tensile of 19 pounds as measured by ASTM D1682 and Do, aTaber 40 cycle abrasion rating of 3.0 as measured by ASTM Do and Handle-O-Meter MD value of 6.6 grams and CD value of 4.4 grams using TAPPI method To. Such spunbonded material is available from Kimberly-Clark Corporation, Roswell, Ga. Theouter cover layer12 has a weight of from about 0.3 ounce per square yard (osy) to about 2.0 osy, preferably about 0.7 osy.
• The position and shape of theleg openings44,46 are important to avoid tightness in the crotch and groin area of the wearer, to obtain adequate buttocks coverage, and to prevent thepanty25 from tilting forward, e.g. tilting such that the front waist edge dips lower in relationship to the back waist edge.FIGS. 1 and 2 illustrate the most preferred design for leg fit and buttocks coverage. The shape of the curve across the top of the leg is important. If the curve is too deep, thepanty25 will shift downward and backward resulting in a short front waist, increased back length and bagginess in the seat of the panty. This would cause thepanty25 to appear tilted when worn as evidenced by an unevenness around the waist of the wearer.
• Thus, the majority of theedge70 of the front portion of eachleg opening44,46 is defined by a straight section72 having a length “L2” at least about 70% of the length “L3” of theentire edge70. The straight section72 should form an angle with the centerline A-A of between about 75 degrees and about 100 degrees, and most preferably about 90 degrees.
• With the panty subassembly10 laid out flat as inFIG. 1, the majority of theedge74 of the back portion of each leg is defined by astraight section76 having a length “L4” at least about 70% of the length “L5” of theentire edge74. Thestraight section76 forms an acute angle with the longitudinal centerline A-A of the subassembly10. More preferably, thestraight section76 of theedge74 forms an acute angle α with the centerline A-A of thepanty25 of between about 50 degrees and 65 degrees and most preferably about 60 degrees.
• The majority of the edge78 of the crotch portion of eachleg opening44,46 is defined by astraight section80 having a length “L6.” Preferably, thestraight sections80 are straight for at least about 70% of the entire lengths “L7” of the respective edges78.
• Each backleg edge portion74 includes an arcuate section “A1” extending from oneend81 of the respectivestraight section76 to asecond end82 connecting the respective back leg edge portion.
• Each frontleg edge portion70 includes an arcuate section “A2” extending from oneend84 of the respective straight section72 to a second end86 connecting the respective frontleg edge portion70 to the front end of edge78 of the respective crotch portion.
• The shape of the arcuate section “A2” at the inner groin area is important. If the arc is too shallow, tightness may be experienced at the inner groin area.
• The preferred narrow crotch width reduces coverage of the buttocks. To compensate for such reduction, the arcuate section “A1” is preferably adjusted towardback waist portion22, such that theend82 of the arcuate section “A1” should be positioned slightly forward of centerline B-B as shown inFIGS. 1 and 2.
• The waist, leg, and body elastics40,48,50,64 respectively are attached to the panty subassembly10, generally between theouter cover layer12 and thebody side layer14, using apparatus and processes described hereinafter.
• Materials suitable for elastics include a wide variety including but not limited to elastic strands, yarn rubber, flat rubber (e.g. as bands), elastic tape, film-type rubber, polyurethane, and, tape-like elastomer, or foam polyurethane or formed elastic scrim. Each elastic may be unitary, multipart, or composite in construction.
• Waist elastic40 is typically about 0.5 inch (13 mm) wide. The elastic may comprise threads, ribbons, a film, or composite. The threads or ribbons may be multiple and may be applied as a composite. Preferably, the waist elastic is threads, more preferably four threads are used as the elastic and the threads are spaced about 0.17 inch (4.3 mm) apart. The threads may be made of any suitable elastomeric material. One suitable material is spandex such as Lycra® threads available from Dupont located in Wilmington, Del. Suitable waist elastics include threads having a total decitex (g/1000 m) of about 3760 for 0.5 inch (13 mm) wide elastic. Adhesive55 is used to bond the elastic between theouter cover layer12 and thebody side layer14. A suitable adhesive includes, for example Findley H2096 hot melt adhesive, available from Findley Adhesives, Milwaukee, Wis.
• The leg elastics48,50, and crotch elastic51, including multiple threads in each, are typically about 0.5 inch (13 mm) wide. The elastic may comprise threads, ribbons, a film or composite. The threads, ribbons, etc., may be multiple and may be applied as a composite. The front leg elastics and the crotch elastics may be threads, preferably numbering three threads which are spaced about 0.17 inch (4.3 mm) apart. Back leg elastics numbering up to six threads may have a width of about 0.75 inch (19 mm) and a spacing of about 0.15 inch (3.8 mm) apart. The threads may be made of any suitable elastomeric material. One suitable material is spandex such as Lycra® threads available from Dupont, Wilmington, Del. Suitable leg elastics include threads having a total decitex (g/1000 m) of about 3760 for a 0.5 inch (13 mm) wide elastic. Adhesive55 is used to bond the several elastics48,50, and51 to theouter cover layer12, thebody side layer14, and thesupport sheet53.
• To provide a snug leg fit and to draw up the sides of thecrotch portion24 to a cradle to receive the primary absorbent, the leg elastics48,50, and the crotch elastics51, are elongated when applied to thelayers12 and14 respectively. Preferably, the leg elastics48,50 are applied in multiple segments, with the amount of elongation of each segment while being incorporated into the subassembly10 being determined according to the position to be occupied by the respective segment. In the case of only front and back leg elastics, the front leg elastics are elongated less than the back elastics. In the case of front elastics, back elastics, and crotch elastics, the front and crotch elastics are elongated less than the back elastics. Preferably, the front and crotch elastics are elongated to about 150% and the back elastics along the leg openings are elongated to about 250% The differing tensions allow easier attachment of the primary absorbent pad66, less tightness in the groin area, and less bunching of thecrotch portion24 caused by high leg elastic retraction. The back leg elastic is under higher elongation to help keep the seat of the panty from creeping up with movement during use.
• Referring now toFIGS. 1,6, and7, the suggested six (back) and three (front) threads of elastic on the respective back and front leg elastics48 and50 are each represented assingle threads112 of elastic. The following description of the characteristics and use of the single threads applies to the usual multiple threads suggested above.
• The composite of the elastics extending about each of theleg openings44 and46 comprises a portion of the back leg elastics48, a portion of the front leg elastics50, and one of the left and right crotch elastics51. Referring specifically toFIGS. 1,6, and7, the back leg elastic48 extends, as afirst section48A, from afirst locus92 at or propinquant theedge28 of the subassembly, width-wise across the subassembly at a substantially consistent acute angle α with the centerline A-A that takes it toward a first edge of the subassembly atfront waist portion18, and generally following theback edge74 of theleg opening46 along thestraight section76A and onto the first arcuate section “A1” toward thecrotch portion24, generally terminating in the first arcuate section “A1,” at or near thecrotch portion24. Back leg elastic48 extends, as asecond section48B, from the first arcuate section “A1” across the crotch portion to the second arcuate section “A1.” From the second arcuate section “A1,” the back leg elastic48 extends, as athird section48C, at an acute angle α with the centerline A-A away from thefront waist portion18, and generally following theback edge74 of theleg opening44 along the straight section76B to asecond locus94 at orpropinquant edge34. In the flat configuration shown for the subassembly inFIGS. 1,6, and7,sections48A and48C are elongated 250%, whilesection48B is relaxed, and under no substantial elongation. Preferably,section48B includes a modest amount of slack in the elastic.
• The front leg elastic50 extends, as afirst section50A, from athird locus96 at or propinquant theside edge26 of the subassembly width-wise across the subassembly and generally following the frontleg edge portion70 along its longitudinalstraight section72A, and onto the first arcuate section “A2” toward thecrotch portion24, generally terminating in the first arcuate section “A2,” at or near thecrotch portion24. Front leg elastic50 extends, as asecond section50B, from the first arcuate section “A2” across the crotch portion to the second arcuate section “A2.” From the second arcuate section “A2,” the front leg elastic50 extends, as athird section50C, width-wise across the subassembly and generally following the frontleg edge portion70 along its longitudinal straight section72B to afourth locus98 at orpropinquant side edge32. In the flat configuration shown for the subassembly inFIGS. 1,6, and7,sections50A and50C are elongated 150%, whilesection50B is relaxed, and under no substantial elongation. Preferably,section50B includes a modest amount of slack in the elastic.
• Thus, in the embodiment seen inFIGS. 1,2,6, and11, the front and rear leg elastics extend across the width W1 of the subassembly10 as one or more continuous threads.
• The crotch elastics51 extend generally between the back and front leg elastics48 and50, with respective ends of the crotch elastics generally being disposed at or near the arcuate sections “A1” and “A2.” Accordingly, the elastic properties extant about each leg opening result from the combined contributions of the respective back leg section (e.g.48A), the respective front leg section (e.g.50A), and the respective crotch elastic51.
• The reason for providing leg elastics in multiple sections is at least two-fold. First, using multiple sections of elastics facilitates placing of the elastics on theouter cover layer12 while maintaining advantageous production speeds. As suggested inFIGS. 1,8, and9, the subassembly of e.g.FIG. 1 is made as a sequence of such subassemblies in acontinuous web100, with the width “W1” of the subassembly disposed in the “with machine” direction of the processing apparatus. In such arrangement, the front and back waist elastics40, the front and back body elastics64, and the front and back leg elastics48,50 can all be assembled into the subassembly by appropriate continuous feeding of respective continuous threads of elastics into the processing apparatus in the “with machine” direction while theweb100 continuously advances in the “with machine” direction at a constant speed.
• Given the orientation of the crotch elastics at essentially 90 degrees to the direction of advance of theweb100, placing the crotch elastics as a portion of a continuous element of either the front or back leg elastics would suggest either (1) momentarily and regularly stopping the advance of theweb100 while the crotch elastic is fed into place, or (2) severely slowing theweb100 and severely driving an elastics guide, in a direction transverse to the web in order to apply the crotch elastic while the web was thus slowed. In either scenario, severe stresses would be placed on the respective drive apparatus, as well as on the web. The invention contemplates, rather, that the crotch elastics are placed in the subassembly10 as a separate operation placing separate elastics segments, where the crotch elastics segments are first elongated and oriented transverse to theweb100, and are then placed on the web as the web passes the appropriate operating station (not shown) subsequent to placing the leg, body and waist elastics in the subassembly, though the sequence of placing the elastics is not critical.
• Referring now toFIGS. 8 and 9, a first continuous web, which ultimately becomescover layer12, is pressed against theassembly roll102 by turning roll104. A second continuous web, which ultimately becomesbody side layer14, passes under adhesive applicator106 and over turning rolls108 and110, and is pressed against theassembly roll102 by turningroll110.Elastic threads112 are fed from acontinuous supply114 of elastic thread through feed nip116, through thread guides118 and sets ofguide fingers120A and120B, and betweencover layer12 andbody side layer14 at the nip formed byassembly roll102 and turningroll110.
• Referring especially toFIGS. 10 and 11, thread guides118 and corresponding sets ofguide fingers120A and120B are elements oflateral guides122A and122B respectively. Each of the lateral guides122A and122B is mounted on atransverse slide bar124 for sliding transverse to the with machine direction of travel of the webs. Eachlateral guide122 is connected to atransverse drive mechanism126 includinglinkage arms128 and130,vertical drive shaft132, and a cam follower. The cam followers follow the corresponding cams inside the respective cam housings. The cams are linked to themachine drive shaft140 bydrive belt142. Thus, the cams, and correspondingly the thread guides and the sets of guide fingers, move transversely with respect to the with machine direction of the webs as the drive shaft turns. The end result is that rotation of the processingline drive shaft140 effects transverse motion of the thread guides and the sets of guide fingers, as indicated by the arrows inFIG. 10, in cooperation with the design of the cams and cam followers.
• Referring toFIG. 8, theguide fingers120 are positioned close to the nip144 so that they closely control the transverse positions of the elastics with respect to thewebs12 and14 as thewebs12 and14 enter the nip144 and correspondingly trap the elastics between them, fixing the position of the elastics between them by means of adhesive55. Accordingly, theguide fingers120 are preferably physically positioned, and provide guidance to the threads of elastic, within one inch of the nip144. To the extent the fingers can be placed closer to the nip144, they provide more positive guidance to the elastic. By careful design of theguide fingers120, and by careful control of the positioning of theguide fingers120 with respect to nip144, theguide fingers120 can be advantageously positioned within 0.5 inch of the line of contact defined at the nip betweenroll102 and108.
• The limitation on how close theguide fingers120 can be placed to the nip is controlled by the ability to design fingers which can affirmatively guide the threads of elastic while avoiding having the fingers themselves drawn into the nip. The criticality of urging the fingers as ultimately close as possible to the nip can be attenuated by directing thethreads112 onto the adhesive-coatedlayer14 ahead of nip144, preferably instantaneously ahead of the nip144, as suggested by the depiction inFIG. 8. By directing the threads of elastic ontolayer14 ahead of the nip, the open distance spanned by the threads between thefingers120 and the adhesive-coatedlayer14 is minimized, being held to less than 0.5 inch, for example 0.25-0.375 inch (6 mm to 10 mm).
• The transverse movement of the lateral guides122, and thusfingers120, as the webs advance along the processing line, creates transverse positioning of theelastics threads112 with respect to the with machine direction of the advancingwebs12 and14.FIG. 11 shows the pattern of transverse movement of the sets ofguide fingers120A and120B relative to the movement of the web in the with machine direction, along the processing line. InFIG. 11, the sets offingers120A and120B are depicted at several locations along the front and back edges of theleg openings44,46, to indicate that it is the positioning of the sets offingers120A and120B, and the dynamic changing of that positioning by thedrive mechanism126, that determines the instantaneous transverse location of the elastics in the web at any point and time while the elastics are being placed in the web at nip144 as shown inFIGS. 8-11. ComparingFIGS. 1,10, and11, it is seen that the set offingers120A generally places the threads of the back leg elastics generally parallel to each other in the web, while the set of fingers120B generally places the threads of the front leg elastics generally parallel to each other in the web, both along their respective portions of the designed paths defining the front70 and back74 edges of theleg openings44 and46. The threads of elastic deviate slightly from their parallel relationships with each other as the elastic threads traverse paths that deviate from the with machine direction, the distance between the threads90 being generally constant as they emerge from thefingers120. Such deviations from the parallel, resulting from the cross machine traverse of the elastics, are included herein within the phrase “generally parallel” as respects the relationships of the threads of elastic to each other.
• It will be understood thatFIG. 11 represents only one panty in the continuous sequence of panty subassemblies10 contained in theweb100 passing through nip144. It will also be understood that the web passing through the nip144 is further acted upon atcutter146 to cut away material from theweb100 in creating theleg openings44 and46.
• In general, then,webs12 and14 are provided as substantially endless rolls from unwind stands (not shown).Web14 is typically provided as front and backlayer elements19 and21.Space23 separates theelements19 and21, and generally corresponds with the crotch portion and the portion of theweb12 which is cut out to formleg openings44 and46. Adhesive55 is applied to the front andback elements19 and21 ofweb14 by adhesive applicator106.Webs12 and14 are joined adhesively, with elastic threads being interposed betweenwebs12 and14 at nip144, and withspace23 interposed between the front andback elements19,21 of thebody side layer14. The transverse positions of the elastics change according to a pre-set path of transverse movements, driven by thedrive shaft140 which drives and times the several operations along the processing line. The threads of elastic112, as placed by theguide fingers120, traverse respective paths that ultimately follow the front and back edges of theleg openings44 and46, as defined atcutter146, in registration with the advance of the web, and accordingly, with the advance of the series of panty subassemblies10 being defined in the web at nip144 andcutter146. The portions of the threads of elastic located along the front and back edges of the leg openings are stretched. The portions traversing the crotch portion are relaxed. The crotch portions of the elastic are separately placed in the subassembly10 at a later processing station, preferably downstream from thecutter146.
• A second embodiment of the subassembly is illustrated inFIG. 12. In the second embodiment, thefront edge148 ofback layer element21 is disposed rearwardly of thatsame edge148 as depicted in the embodiment ofFIG. 10, while theguide fingers120A traverse the same path as inFIG. 10. Accordingly, as the threads of elastic112 extend across thecrotch portion24, thethreads112 are guided forwardly ofedge148, intospace23, and are thus not held between thelayers12 and14, and thus are not controlled by the adhesive onlayer14. Rather, the tension is maintained on the threads of elastic112 across thecrotch portion24, such that the threads retract along theedge148 of thelayer element21 in a configuration that loosely resembles a rope under tension. The rope is subsequently cut such that the cut portions of the threads retract to positions generally defined by the intersection of theedge148 of theback layer element21 and the path of the threads adhesively held betweenlayer12 and theback layer element21. Thus, thethreads112 generally include loose intermediate ends150 after being cut, as shown inFIG. 7.
• Body elastics64 and waist elastics40 can be incorporated at nip144 in the conventional manner of providing stationary feeds and guides at the nip.
• In another embodiment of the invention shown inFIG. 13, a section ofweb processing equipment297 is shown including a drive side DS and an operator side OS. As generally shown, a plurality ofelastic threads212 are attached to a stain shield or secondaryabsorbent web267, and thesecondary absorbent267 and attachedelastic threads212 are cut to create a plurality of stain shields268 having respective elastic pieces orsections251A attached thereto. The elasticized stain shields268 are maneuvered as shown and attached to agarment web201 to form a garment blank subassembly. This garment blank subassembly is similar in many ways to the embodiments described above; therefore, only certain features of this embodiment are described below for the sake of brevity and reference is made to the foregoing descriptions for like or similar components of the garment blank subassembly to enable this aspect of the invention.
• With more particular reference toFIG. 13, theprocessing equipment297 supplies the plurality ofelastic threads212 from anelastic thread roll214 generally in a machine direction MD. Theelastic threads212 are routed by a series of guide rollers G in a known manner and are attached in a stretched condition in a non-machine direction (NMD) in this example to the secondaryabsorbent web267 using an adhesive255A. As shown, the adhesive255A is applied intermittently to theelastic threads212 by a plurality ofapplicators206A to form a plurality ofadhesive gaps213 along theelastic threads212. Thecutter246 cuts the secondaryabsorbent web267 into the stain shields268 at eachadhesive gap213. As further shown, thestain shield268 theresultant sections251A are attached to a first orinner side268B, which opposes a second orouter side268A discussed further below.
• Theexemplary cutter246 shown inFIG. 13 is a roller cutter having a plurality of blades246A,B attached thereto for cutting theelastic sections251A at theadhesive gaps213 as discussed above. Thecutter246 is controlled by acontroller299 disposed on the operator side OS of theprocessing equipment297 in this example. Those skilled in the art will instantly recognize that thecontroller299 can be a computer or a programmable logic controller, which can be programmed to cut theelastic threads212 at theadhesive gaps213 based on a passage of time or a sensed length of passingelastic threads212 to create thesections251A. As shown, each end of eachsection251A, which formed thegaps213 in theelastic threads212 before theelastic threads212 were cut, retract after being cut to create a retraction area268C on theouter side268B. In this example, thesections251A are from about one (1) inch to about three (3) inches in length.
• As further shown inFIG. 13, a secondadhesive applicator206B applies a second amount of adhesive255B to theouter sides268B of the stain shields268. As shown, a plurality of applicator assembly segments297A-D subsequently maneuver or rotate the adhesive coated stain shields268 transverse to the machine direction MD. As further shown, the applicator assembly segments297A-D affix the adhesive coatedouter sides268B and the underlyingelastic sections251A to thegarment web201 with theinner sides268A facing upward or outward from within a crotch area orportion224. As shown, theinner sides268A are located between a plurality ofgarment elastics251B. In this manner, the individualelastic sections251A are rapidly manipulated, positioned and attached to thecrotch area224 without having to maneuver theentire garment web201 and/or cut theelastic threads212 and apply theelastic sections251A to thecrotch portions224 through acute angles at high machine speeds.
• Wherever herein this teaching refers to “multiple” elements, e.g. multiple threads of elastic or multiple paths of traverse, any two or more such elements are included.
• Having thus described the invention in full detail, it will be readily apparent that various changes and modifications may be made without departing from the spirit of the invention. All such changes and modifications are contemplated as being within the scope of the present invention, as defined by the following claims.

Claims (16)

That which is claimed is:

1. A disposable garment comprising:

a front body portion, a back body portion, and a crotch portion in between the front body portion and the back body portion, the front body portion and the back body portion being connected together to form a waist opening, a first leg opening, and a second leg opening, the first leg opening being surrounded by a first front leg edge portion, a first back leg edge portion, and a first crotch leg edge portion positioned in between the first front leg edge portion and the first back leg edge portion, the second leg opening being surrounded by a second front leg edge portion, a second back leg edge portion, and second crotch leg edge portion positioned in between the second front leg edge portion and the second back leg edge portion;

an absorbent located at least within the crotch portion;

an elastic having a first end near a first outer edge of one of the body portions and extending along the first leg edge portion and the second leg edge portion to a second end near a second outer edge of the same body portion, the elastic having been cut to form a first intermediate end spaced from a second intermediate end; and

a plurality of opposing crotch elastics extendably affixed to opposing edges of the crotch portion on each side of the crotch portion.

2. The disposable garment ofclaim 1, having a second elastic having a first end near a first outer edge of the body portion free of the first elastic and extending along the first leg edge portion and the second leg edge portion to a second end near a second outer edge of the same body portion, the second elastic having been cut to form a first intermediate end spaced from a second intermediate end.

3. A disposable garment as inclaim 1, wherein the intermediate ends are retracted.

4. A disposable garment as inclaim 3, wherein the retracted intermediate ends are free from adhesive.

5. A disposable garment as inclaim 2, wherein the first and second elastics have been cut into a plurality of elastic sections.

6. A disposable garment as inclaim 1, wherein the waist opening is surrounded at least in part by a waist elastic.

7. A disposable garment as inclaim 6, wherein the waist elastic comprises threads, ribbons, a film, or a composite.

8. A disposable garment as inclaim 1, wherein the front body portion and the back body portion include body elastics positioned between the waist opening and the leg openings.

9. A disposable garment as inclaim 1, wherein the garment defines a length direction and a width direction transverse to the length direction, wherein the crotch elastics extendably affixed to opposing edges of the crotch portion extend in the length direction of the garment.

10. A disposable garment as inclaim 1, wherein the garment defines a length direction and a width direction transverse to the length direction, wherein the crotch portion is free from continuous elastics spanning the width direction of the garment.

11. A disposable garment as inclaim 1, wherein the opposing crotch elastics and the first and second elastics overlap.

12. A disposable garment as inclaim 1, wherein the garment has a body side liner positioned to face the wearer.

13. A disposable garment as inclaim 12, wherein the body side liner comprises a front body portion element and a back body portion element which are separate from one another.

14. A disposable garment as inclaim 1, wherein the intermediate ends are adjacent the crotch portion.

15. A disposable garment as inclaim 1, wherein the intermediate ends extend over the crotch portion.

16. A disposable garment as inclaim 2, wherein at least one of the first or second elastic is angled with respect to a longitudinal centerline of the disposable garment.

Images