METHOD FOR MAKING BOXER-TYPE BRIEFS AND BOXER-TYPE BRIEFS MADE ACCORDING TO THE METHOD
TECHNICAL FIELD
The invention pertains to boxer-type briefs and boxer-type briefs made according to the method.
BACKGROUND OF THE INVENTION
Disposable pant articles like pant diapers, sanitary pants and incontinence pants have a comfortable fit and are capable of being pulled up and down over the hips of the wearer to allow the wearer or caregiver to easily put on and remove the article when it has been soiled. The pant articles may be provided with openable and optionally reclosable side seams in order to avail a user or care-taker of the possibility of putting on and/or taking off the article while the side seams are in an open state. Absorbent pant articles in the form of boxer briefs resemble conventional underwear and are preferred by many users.
However disposable boxer briefs present manufacturing challenges and product design is often compromised by cost and manufacturing aspects. This is in part due to the fact that a high manufacturing speed is necessary to be able to produce low-cost disposable absorbent articles.
A particular problem encountered in the production of boxer-type briefs is to provide the briefs with a three-dimensional crotch shape with leg hoop portions having sufficient width to accommodate a wearer's thighs In US 3,678,516, extra leg width is accomplished by creating a tube-shaped pant blank having a width corresponding to the waist width of the finished pant, sealing the blank to create a "fly" at the front of the pant blank, folding triangular edges of the blank below the fly, and attaching a rectangular piece of crotch material over the folded parts of the tubular blank.
US 7, 198,688 discloses a process for making boxer shorts, for example in the form of disposable absorbent articles. The garment shell of the boxer shorts is provided from a flat web having leg openings therein. The flat web is contracted in the crotch region to provide hanging legs and side seams are formed to create a boxer shorts type pant.
International patent applications WO 2008/141756 and WO 2008/141658 disclose a pant comprising a centre piece with a front waist region, a crotch region and a back waist region. The pant may comprise side panels connected to the centre piece. The pant comprises leg hoops formed at the leg openings. In the production of the disclosed pant, material for the leg hoops is provided in appropriate lengths that are folded to create a loop-shape and subsequently attached to the material forming the main part of the pant.
The known articles are produced by complicated methods involving handling of discrete strips and pieces of material as well as a large number of intricate folding and bonding steps carried out in order to provide the articles with the desired shape. Accordingly, there remains a strong need for an improved and simplified method of producing boxer-type briefs.
SUMMARY OF THE INVENTION
In accordance with the invention, there is provided an improved method for producing boxer-type briefs characterised in that the method comprises the steps of: a) feeding a first continuous web along a production path in a machine direction, MD, the first continuous web having a cross machine direction, CD, transverse to the machine direction, MD, a width in the cross machine direction, CD, and first and second parallel side edges extending in the machine direction; b) feeding a second continuous web along the production path in the machine direction, MD, the second continuous web having a cross machine direction, CD, transverse to the machine direction, MD, a width in the cross machine direction, CD, and first and second parallel side edges extending in the machine direction; c) arranging the first and second continuous webs in an overlapping configuration with the second continuous web being arranged over the first continuous web and with the second side edges of the first and second continuous webs being brought into alignment with each other, the first continuous web and the second continuous web forming a dual-layer base web having a dividing line between the first and second continuous webs, the dividing line extending in the machine direction, MD, along the second side edges of the first and second continuous webs; d) intermittently bonding the first and second continuous webs to each other within rectangular bond areas extending in the cross machine direction, CD, from the second side edges of the first and second continuous webs towards the first side edges of the first and second continuous webs, the bond areas extending in the cross machine direction, CD, a distance corresponding to less than half the width of the first continuous web and less than half the width of the second continuous web and having an outer end point at the second side edges of the first and second continuous webs and an inner end point at a distance from the second side edges of the first and second continuous webs; e) forming a T-shaped cut through the base web at each bond area, the T-shaped cut having a first cut segment extending across the second side edges of the first and second continuous webs, centrally through the bond area in the cross machine direction, CD, and terminating at the inner end point of the bonding area and having a second cut segment at the inner end point of the bonding area, the second cut segment extending in the machine direction, MD, perpendicular to the first cut segment; f) bringing the base web into a single-layer configuration by folding the second continuous web away from the first continuous web along the dividing line in the base web and causing the intermittently bonded and cut portions of the single layer base web to assume a configuration with first and second triangular pockets arranged on each side of an hourglass shaped hole in the single layer base web, the first and second triangular pockets being open at first and second edges extending in the cross machine direction and having pointed ends directed towards the hourglass shaped hole; g) attaching a supplementary material over each hourglass shaped hole; and h) severing the base web in the cross-machine direction between each hourglass shaped hole.
With the method of the invention boxer-type briefs having extra leg-room may be formed without handling or folding of discrete web parts to provide additional material at the legs of the boxer-type briefs. In accordance with the method of the invention, no handling or folding of discrete web parts is required in addition to or separate from folding of the base web. This is a great advantage in that no particular folding equipment is needed in order to form the leg encircling parts of the boxer-type briefs. The only folding that has to be performed in the method of the invention is the longitudinal continuous un-folding of the base web that is carried out to bring the base-web into a single-layer configuration while simultaneously forming leg-space increasing pockets in the web. A second folding step may again be performed to bring the base web back into a two-layer configuration after the supplementary material has been attached over each hourglass shaped hole and before severing of the base web to form individual boxer-type briefs.
The purpose of the supplementary material is to mend the hourglass shaped holes in the base web and to create a whole crotch portion in the finished boxer-type brief. The supplementary material may be attached to the base web on each side of the hourglass shaped hole as seen in the cross machine direction, corresponding to attachment arranged at the front and back of each boxer-type brief. This means that the
supplementary material needs to have a CD extension which is larger than the CD extension of the hourglass shaped hole. Furthermore, the supplementary material is preferably attached to the triangular pockets on each side of the hourglass shaped hole as seen in the MD. Accordingly, in the area of the base web where the supplementary material is applied over the hourglass shaped hole, the supplementary material may have a smallest width, or MD extension, that is equal to the maximal width or MD extension of the hourglass shaped hole or the supplementary material may have a width that is slightly larger than the maximal MD width of the hourglass shaped hole.
Each triangular pocket has an edge extending in the cross machine direction at the open end of the pocket. The supplementary material may be attached to the triangular pockets with narrow bonding lines arranged in the CD along said first and second edges of said first and second triangular pockets. Alternatively, the supplementary material may be attached to the triangular pockets over the full overlapping area between the
supplementary material and the pockets on each side of the hourglass shaped hole or in a band-shaped area extending from the CD edges of the triangular pockets over only a portion of the triangular pockets in a direction towards the hourglass shaped hole. In the fully assembled boxer-type brief, the CD edges of the attachment that are located closest to the hourglass shaped hole between the triangular pockets will act as hinge means about which the legs of the boxer-type brief will fold downward from the crotch portion of the boxer-type brief. Accordingly, the length of the legs downward beyond the crotch portion is determined by the location of the attachments for the supplementary material on each side of the hourglass shaped hole.
The greatest leg length is obtained when the attachments are formed by line bonds along the first and second CD edges of the triangular pockets and the smallest leg length is obtained when the attachments are formed in the full overlapping area between the supplementary material and the triangular pockets on each side of the hourglass shaped hole. All intermediate leg lengths may be obtained by arranging the attachments further towards the hole, i.e. further towards the points of the triangular pockets. It is conceivable within the scope of the invention to arrange breakable bonds such as a row of line bonds between the supplementary material and the triangular pockets. The breakable bonds may be deliberately peeled apart by a wearer or a care-taker in order to select a desired leg length.
The intermittent bond areas may be formed by means of any suitable method such as by means of adhesive, by ultrasonic bonding, by thermobonding or by stitching or needling. If thermobonding or ultrasonic bonding is being used, the base web material needs to comprise a sufficient amount of thermoplastic material in order to obtain adequate bond strength. The first and second continuous webs may be bonded to each other with a continuous band-shaped bond formed over the whole bond area. Alternatively, the bond area may comprise a plurality of discrete bonds distributed over the bond area. Such discrete bonds may be point bonds or line bonds, as commonly used to form seams or joins in disposable garments. Line bonds may be arranged in the MD or CD and may be continuous or discontinuous. By way of example, each rectangular bond area may comprise two parallel bonds, arranged in the CD, wherein the first cut segment is arranged between the two parallel bonds.
The rectangular bond areas may have an extension in the machine direction of 10 to 60 millimeters, such as from 20 to 50 millimeters. The rectangular bond areas may have an extension in the cross machine direction of up to half the extension of the dual layer base web in the cross machine direction, such as a CD extension of up to 300 millimeters or a CD extension of up to 200 millimeters. The rectangular bond areas preferably have a CD extension of at least 40 millimeters or a CD extension of at least 50 millimeters. The first cut segments of the T-cuts which are the cuts that are arranged in the rectangular bond areas have the same CD extension as the rectangular bond areas.
The second cut segments of the T-cuts, i.e. the cut segments extending in the machine direction perpendicular to the rectangular bond areas and the first cut segments of the T- cuts, may have an extension in the machine direction (MD) of from 80 millimeters to 300 millimeters, such as from 100 millimeters to 200 millimeters. In a finished boxer-type brief, the length of the second cut segments defines the inner leg width of the brief.
After attaching the supplementary pieces of material to the single layer base web, the base web may be brought into a dual layer configuration by folding the second web towards the first web along the dividing line such that the first and second triangular pockets become arranged between the first continuous web and the second continuous web. The folding step is preferably carried out before severing the base web in the cross- machine direction between each hourglass shaped hole in the base web. If desired, side seams may be created in the cross machine direction after folding of the single layer base web. The side seams are preferably openable side seams and may also be reclosable.
The method of the invention may alternatively be used to produce open boxer-type briefs, such as open diapers and diaper covers that are provided with closure means such as fastening tabs for fastening the garment around the waist of a wearer. The supplementary piece of material may comprise or consist of a material selected among: nonwovens, films and laminates. It may be preferred that the surface of the supplementary piece of material that will be exposed to the outside of the boxer-type brief through the hole in the base web is a nonwoven material or a material having an outer textile or textile like surface in order to enhance the impression of the boxer-type brief being ordinary textile underwear.
The supplementary crotch material may be similar in colour and texture to the base web material to camouflage the contours of the hole in the base web. Alternatively, the crotch material may be selected to provide a contrast to the base web material such that it can be identified visually and/or by touching the material. To this end, one or more of colour, texture, gloss or type of material may differ between the crotch material and the base web. A transparent material, such as a transparent plastic film or viewing window may be used to provide a visual indication of wetness in an absorbent disposable garment. The crotch material may also provide sensory wetness indication. Liquid that has been absorbed in the garment will make a plastic film feel warmer or colder than a surrounding material such as a thicker film material or a material with better isolating properties such as a nonwoven or a porous film or foam material. The crotch material may further be used to provide decoration, size indication, an indication of the gender of the intended wearer, etc.
The supplementary material may comprise an absorbent core or an absorbent material such as one or more layers of absorbent nonwoven, tissue-paper or laminates containing superabsorbent material. Furthermore, the supplementary material may be comprised in a core pack, the core pack comprising a topsheet layer, a backsheet layer and an absorbent core between the topsheet layer and the backsheet layer and having side edges extending in the cross machine direction. A core pack is a prefabricated component that may include further components in addition to the covering layers and absorbent core as set out herein.
By way of example, the core pack may be provided with elastic elements arranged in the cross machine direction along each side edge of the core pack.
The supplementary material may be attached to the base web by means of any suitable method or combination of methods as known in the art, with adhesive bonding being preferred. When carrying out the bonding step, care should be taken to bind the supplementary material to the base web without sealing the pockets. The bonding may be made in any suitable pattern that will provide adequate attachment between the base web and the supplementary material. As set out above, the bonding pattern may be used to regulate the leg length of the boxer-type brief.
The base web may further be provided with waist elastic that is applied continuously or intermittently along at least one side edge of the base web. The method according to the invention may also include application of body elastic arranged between the waist elastic and the hourglass shaped holes in the base web. The boxer-type briefs produced according to the invention will have hanging legs formed by the triangular pockets through the bonding and cutting steps of the method according to the invention.
DEFINITIONS
As used herein a "boxer-type brief" or "boxer short" is any kind of garment that is worn in a pant-like fashion around the lower trunk of a user's body and that has a three- dimensionally shaped crotch portion with leg-encircling loops on each side of the crotch portion. The boxer-type brief may be a pair of disposable, non-absorbent underpants that may be worn with or without an absorbent insert. Accordingly, the boxer-type brief may be a disposable absorbent or non-absorbent sanitary pant, a pant diaper, an open diaper or a diaper cover having fastening means for fastening the diaper or diaper cover in a pant-like configuration on a user's body.
The boxer-type brief according to the invention may comprise a chassis. A chassis as used herein is a coherent structure with a main function of supporting and connecting components of the boxer-type brief such as elastic elements and absorbent components. The outer side or outer surface of a web used in the production of the boxer-type brief of the invention or of the boxer-type brief of the invention is the side or surface of the web or the brief made from the web that is intended to be facing away from a wearer of the brief when the brief is being worn. The inside or inner surface of a web used in the production of the boxer-type brief of the invention or of the boxer-type brief of the invention is the side or surface of the web or the brief made from the web that is intended to be facing towards a wearer of the garment when the garment is being worn. A "layer" or a "web" as used herein is a generally two-dimensional structure that may comprise one or more plies and may be in the form of a laminate made from plies of the same or different materials. An "elastic" material as used herein is to be understood in the conventional way as being a material that after stretching resiliently returns to a less extended state, ideally to its original, unstretched state. BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in greater detail below with reference to the figures shown in the appended drawings.
Figure 1 A shows initial production steps of a method according to the invention;
Figure 1 B shows the final production steps of the method in Fig. 1A;
Figure 2A-2C show unfolding of a base web according to the invention; Figure 3A-3C show different attachment patterns for attaching a supplementary
material to a base web according to the invention;
Figure 4A shows a boxer-type brief made according to the method of the invention; Figure 4B shows a variant of the boxer-type brief in Figure 4A; and
Figure 5 shows a boxer-type brief made according to the method of the invention.
DETAILED DESCRIPTION OF EMBODIMENTS
Figs. 1 A and 1 B are schematic illustrations of a method for the production of a pair of boxer-type briefs in accordance with the invention. The method is of a kind commonly referred to as a "cross-direction" production method implying that the side edges of the production web or "base web" as herein defined will be placed at the waist edges of the assembled boxer-type brief. Although the shown process involves attaching an absorbent core in the crotch portion of the boxer-type briefs and the formation of side joins, it is to be understood that such process steps are optional to the invention. Accordingly, the process shown in Figs. 1A and 1 B may be modified to produce boxer-type briefs with a non- absorbent supplementary material and/or without side joins. As is shown in Fig. 1A, a first continuous web 1 is continuously moved along a production path in a machine direction, MD. The first continuous web 1 has a cross machine direction, CD, transverse to the machine direction, MD, and first and second parallel side edges 2,3 extending in the machine direction, MD.
A second continuous web 4 is continuously moved along the production path in a machine direction, MD. The second continuous web 4 has a cross machine direction, CD, transverse to the machine direction, MD, and first and second parallel side edges 5,6 extending in the machine direction, MD.
The first and second continuous webs 1 ,4 are arranged in an overlapping configuration with the second continuous web 4 being arranged over the first continuous web 1 and with the second side edges 3,6 of the first and second continuous webs 1 ,4 being brought into alignment with each other. In this manner, the first and second continuous webs 1 ,4 form a dual-layer base web 7 having a dividing line 8 between the first and second continuous webs 1 ,4, the dividing line 8 extending in the machine direction, MD, along the second side edges 3,6 of the first and second continuous webs 1 ,4.
The first and second continuous webs 1 ,4 may have the same or different compositions and can consist of any flexible web material as commonly used in the art, such as nonwoven material, plastic film, or laminates of two or more sheets of the same or different materials. Furthermore, the first and second continuous webs 1 ,4 may be compound webs formed from two or more parts that have been bonded together to form a coherent web. Compound webs may, for instance, be used to provide different properties such as different breathability, elasticity, tear strength, softness, etc. in different areas of the compound web. The first and second continuous webs 1 ,4 may be elastic or inelastic and will preferably comprise or consist of at least one nonwoven layer. Suitable nonwoven materials are carded bonded nonwovens, spunbond nonwovens, spunlaced nonwovens, meltblown nonwovens and laminates and combinations thereof. The nonwoven webs may comprise or consist of thermoplastic fibres. The first and second continuous webs 1 ,4 according to the invention will form portions of a chassis in a boxer-type brief and also usually form part of seams and joins in the brief. For this reason, it is highly desirable that the first and second continuous webs 1 ,4 comprise thermoplastic material and is weldable by heat or by ultrasonic welding processes. Examples of suitable polymers for use in the base webs according to the invention are polyethylene, polyesters, polypropylene and other polyolefin homopolymers and copolymers. A weldable nonwoven web preferably has a high content of thermoplastic fibres and may contain at least 50% thermoplastic fibres and preferably at least 80% thermoplastic fibres. The base web 7 may be formed from first and second continuous webs 1 ,4 having the same width, or CD extension such that the unfolded base web 7 is symmetrical about the dividing line 8 as shown in Fig. 1A and 1 B. However, the base web may be formed from first and second continuous webs 1 ,4 of different widths. By way of example, it may be desirable to add elastic waist features of different widths or an elastic body panel to one or both side edges 2,5 of the base web 7 after unfolding of the dual layer web 7 to form a single layer base web 7. In order to further process the web in the production of closed boxer-type briefs, the web may subsequently be folded back into a dual-layer
configuration along a longitudinal centre line of the single layer base web before making side seams and cutting the web into individual boxer-type briefs.
After arranging the first and second continuous webs 1 ,4 on top of each other, the webs are intermittently bonded to each other within rectangular bond areas 9 extending in the cross machine direction, CD, from the second side edges 3,6 of the first and second continuous webs 1 ,4 in a direction towards the first side edges 2,5 of the first and second continuous webs 1 ,4. The bond areas 9 extend in the cross machine direction, CD, a distance corresponding to less than half the width of the base web 7 with an outer end point 10 at the second side edges 3,6 of the first and second continuous webs 1 ,4 and an inner end point 1 1 at a distance from the second side edges 3,6 of the first and second continuous websl ,4.
The intermittently formed bond areas 9 will form inner leg seams in the finished boxer- type brief and may be made by means of any suitable method such as by means of adhesive, by ultrasonic bonding, by thermobonding or by stitching or needling. If thermobonding or ultrasonic bonding is being used, the base web material needs to comprise a sufficient amount of thermoplastic material in order to obtain adequate bond strength.
The first and second continuous webs 1 ,4 may be bonded to each other with a continuous bond formed over the whole bond area 9. Alternatively, each bond area 9 may comprise a plurality of discrete bonds distributed over the bond area 9. Such discrete bonds may be point bonds or line bonds, as commonly used to form seams or joins in disposable garments. Line bonds may be arranged in the MD or CD and may be continuous or discontinuous. In Figs. 1A and 1 B, each rectangular bond area is shown by way of example to consist of two parallel line bonds, extending in the CD.
The bonded webs are cut by forming a T-shaped cut 12 through the base web at each bond area 9. The T-shaped cut 12 is made with a first cut segment 13 extending in the cross machine direction, CD, from the second side edges 3,6 of the first and second continuous webs 1 ,4, centrally through the bond area 9 and terminating at the inner end point 1 1 of the bond area 9. Accordingly, in Fig. 1 A, the first cut segment 13 is shown to be arranged in the unbonded gap between the two parallel line bonds in the bond area 9.
The T-shaped cut 12 has a second cut segment 14 arranged at the inner end point 1 1 of the bond area 9 and extending in the machine direction, MD, perpendicular to the first cut segment 13. The first and second cuts may be formed simultaneously or in different cutting steps by any suitable means such as rotary die cutting ( DC), laser cutting, water jets, ultrasonic cutting, etc.
The base web 7 is then brought back into a single-layer configuration by folding the second continuous web 4 away from the first continuous web 1 along the dividing line 8 in the base web 7. By folding out the two-layer base web, the intermittently bonded and cut portions of the base web 7 are forced into a configuration with first and second triangular pockets 16, 17 arranged on each side of an hourglass shaped hole 18 in the single layer base web 7. The first and second triangular pockets 16,17 are open at first and second edges 20,21 extending in the cross machine direction, CD, and have pointed ends 22,23 directed towards the hourglass shaped hole18.
Figs. 2A-2C show a portion of a base web 7 during different stages of unfolding a dual layer web to a single layer web. In Fig. 2A the web portion is shown with the second continuous web 4 on top of the first continuous web 1 after the bond area 9 and the T- shaped cut 12 have been formed at the aligned edges 3,6 of the first and second continuous webs 1 ,4.
Fig. 2B shows an intermediate stage of the unfolding step where the triangular pockets 16,17 and the hourglass shaped hole 18 between the pockets have started to form. It can be seen in Fig. 2B that folding out of the second continuous web 4 from the first continuous web 1 along the dividing line 8 forces the two parts 9a, 9b of the bond area 9 that are located on either side of the first cut segment 13 to move apart and to rise up from the main surface of the base web 7. At the same time, the edges formed at the second cut segment 14 of the T-shaped cut 12 move apart. As is shown in Figs. 2B and 2C, the cut edges closest to the side edges of the base web 7 form MD edges 14a', 14b' of the hourglass shaped hole 18 and the cut edges closest to the dividing line 8 form edge parts 14a", 14b"; 14a'", 14b'" that continue move apart in the machine direction as the base web 7 is unfolded into the configuration shown in Fig. 2C.
When the base web 7 has been fully unfolded, the edge parts 14a", 14b"; 14a'", 14b'" and the two parts 9a, 9b of the bond area 9 have been folded back and moved into overlaying contact with the remainder of the base web 7. As is shown in Fig. 2C, the folded-back material at the divided bond area 9 form triangular pockets 16, 17 on each side of the hourglass shaped hole 18 in the base web 7. The inner edges of the pockets 16, 17 are constituted by folds 35 in the base web that also constitute CD edges of the hourglass shaped hole 18. The folds 35 extend from a closed pointed end 22,23 of each pocket 16, 17 towards an open end of the pocket 16, 17 that is directed away from the hourglass shaped hole 18. At the open ends of the triangular pockets 16, 17, the cut edge parts 14a", 14b" and 14a'", 14b'" form CD edges 20 and 21 of the pockets 16, 17
In a finished boxer-type brief, the two parts 9a, 9b of the divided bond area 9 will extend downward from the crotch portion of the brief and form inner leg seams of the briefs. The non-bonded portions of the side edges 3,6 of the first and second continuous webs 1 ,4 extending along the dividing line 8 in the base web 7 form leg openings in the briefs. The material in the triangular pockets 16, 7 form gussets at the inner sides of the legs, thus providing the briefs with extra leg-room.
After bringing the base web 7 into a single layer configuration, adhesive is applied to the base web 7 around each hourglass shaped hole 18 in an attachment area 25 having a window 26 for the hourglass shaped hole 18. The adhesive will be used to attach a supplementary material such as a core pack to the base web 7 in a down-stream production step. The adhesive may be a hot melt adhesive that is applied to the base web 7 by any suitable method such as spraying, slot coating, gravure printing, meltblowing, etc. The adhesive may be uniformly distributed within the attachment area 25 or may be applied in different amounts and different patterns in different parts of the attachment area 25 as 5 exemplified by Figs 3A-3C. By way of example, it may be desirable to use more adhesive or a stronger adhesive in the narrow CD parts, e2, of the attachment areas 25 which extend along each CD edge 20,21 of the triangular pockets 16, 17 as this adhesive will provide the only attachment between the supplementary material and the base web 7 in the area of the base web 7 that will be located in the crotch portion of the assembled 10 boxer-type brief. Depending on the size and configuration of the core pack or other
supplementary material to be applied to the attachment area 25, the shape and size of the attachment area 25 may be different from those shown in Fig. 1 A.
Figs. 3A-3C show portions of a base web 7 having differently configured attachment areas
15 25 for attaching a core pack 26 or some other supplementary material over the hour-glass shaped hole 8 in the base web 7. The figures illustrate that the attachment area 25 may take on any suitable configuration depending on the amount of attachment that is desired between the supplementary material and the base web and further depending on the desired leg configuration of the finished boxer-type brief as will be further discussed
20 herein with reference to Figs. 4A, 4B and Fig. 5. With particular reference to Fig. 3A, the adhesive attachment area 25 comprises a plurality of discrete adhesive portions with narrow band shaped portions e e2 arranged along the CD edges 20,21 of the triangular pockets 16,17 and further discrete adhesive areas positioned on either side of the hourglass shaped hole 18 in the CD. A section through the base web 7 in Fig. 3A is taken
25 along the line A-A, and shows how the different layers of the base web 7 in the area of the hourglass shaped hole 18 are disposed in relation to each other. Accordingly, the triangular pockets 16, 7 form gussets at the divided bond areas 9', 9" where the first continuous web 1 and the second continuous web 4 are joined to each other. The triangular pockets 16,17 have open ends at the CD edges 20,21 . A supplementary piece
30 of material indicated as a core pack 26 in Fig. 3A is attached to the triangular pockets 16, 17 by means of the parts , e2 of the adhesive area 25 that are arranged along the first and second edges 20, 21 of the triangular pockets to form an accordion-like structure on each side of the hourglass shaped hole 18. In the finished boxer-type brief, the accordion-like structure will be unfolded to create legs hanging down from the crotch
35 portion of the brief. The core pack 26 is shown to be attached to the triangular pockets 16, 17 with bonding lines e^ e2 arranged along the first and second edges 20,21 , in the CD. Alternatively, the core pack 26 or other supplementary material may be attached to the triangular pockets 16,17 over the full overlapping area between the core pack 26 and the triangular pockets 16,17 as shown in Fig. 3C or in a band-shaped area extending from the first and second edges, 20,21 , of the triangular pockets 16, 17 over only a portion of the triangular pockets 16,17, in a direction towards the hourglass shaped hole 18, as shown in Fig 3B. In the fully assembled boxer-type brief, the inner edges 25', 25" of the attachment area 25 being the CD edges of the attachment area 25 facing the hourglass shaped hole 18, will act as hinge means about which the legs of the boxer-type brief will fold downward from the crotch portion of the boxer-type brief. Accordingly, in the finished boxer-type brief, the length of the legs downward beyond the crotch portion is determined by the positioning of the attachments for the core pack 26 or supplementary material on each side of the hourglass shaped hole 18.
The greatest leg length in a finished boxer-type brief may be obtained when the attachments are formed by line bonds along the first and second CD edges of the rectangular sheet of material, as shown in Figs. 1A.1 B and 3A and the smallest leg length is obtained when the attachments are formed in the full overlapping area between the core pack 26 and the triangular pockets 16, 17 as shown in Fig 3C. All intermediate leg lengths may be obtained by letting the attachments extend further towards the hole 18, i.e. further towards the pointed ends 22,23 of the triangular pockets 16,17 as shown in Fig 3B.
When the adhesive has been applied to the attachment area 25, a core pack 26 is applied to each attachment area 25 as shown in Fig 1 B. The core pack 26 covers the hour-glass shaped hole 18 and extends in the CD towards the side edges 2,5 of the base web 7. The core pack 26 is not a necessary feature of the invention and may be substituted by any other suitable supplementary piece of material to cover the hour-glass shaped hole 18 in the base web 7.
A "core pack", as used herein is a separately produced component that is integrated with the base web 7 and includes an absorbent core enclosed between a topsheet and a backing layer. The core pack 26 may be adhesively attached to the base web 7, as shown in Figs. 1A and 1 B. However, any other suitable bonding means such as thermo-bonding or ultrasonic bonding may be used as long as care is taken not to seal the triangular pockets. Although the core pack 26 is shown in Fig. 1 B to have a rectangular shape, the core pack 26 may take other forms such as hourglass shape, trapezoidal shape, etc. Furthermore, the core pack 26 may be larger or smaller than the core pack 26 shown in Fig. 1 B providing it covers the hour-glass shaped hole 18 in the base web 7.
The various components included in the core pack 26 can be connected to one another in a conventional manner, for example by adhesive bonding, ultrasonic bonding or thermobonding. The core pack can of course contain further components in addition to those described here, such as a liquid transport sheet, elastic members, shape-stabilizing members, shaping elements, side barriers, etc.
The liquid-permeable topsheet can consist of any material known for the purpose, such as a layer of nonwoven material, a perforated plastic film, net material, tow, or the like. The topsheet can, of course, also consist of a laminate of two or more sheets of the same or different material.
The backing layer is preferably liquid impermeable and can consist of or comprise a liquid-impermeable plastic film, a nonwoven sheet which has been coated with a liquid barrier material, or some other flexible material sheet which has the ability to withstand liquid penetration. However, it may be advantageous if a liquid-impervious barrier layer has some degree of breathability, i.e. permits the passage of water vapour through the sheet. In the assembled boxer-type brief, the backing layer will be visible through the hour-glass shaped hole 18 in the base web 7. Accordingly, an outer, garment-facing layer of the backing layer may be selected to be similar in colour and texture to the base web material to camouflage the contours of the hole in the base web. Alternatively, the garment-facing surface of the backing layer may be selected to provide a contrast to the base web material such that it can be identified visually and/or by touching the material. To this end, one or more of colour, texture, gloss or type of material may differ between the material that is visible through the hour-glass shaped hole 18 and the base web material. The same considerations apply when selecting a supplementary crotch material to cover the hour-glass shaped hole 18 when producing boxer-type briefs without a core- pack. The absorption core can be made up of absorbent material, such as cellulose fluff pulp, tissue, absorbent foam, etc. It is also possible for the absorption core to contain superabsorbents, i.e. polymer materials which are able to absorb body fluid corresponding to many times their own weight and form a hydrogel. Such superabsorbents are usually present in the form of particles, but fibres, flakes, granules and films are also available. Moreover, the absorption core can comprise non-absorbent components such as stiffening elements, shaping elements, binders, etc. Various types of liquid-receiving porous structures such as fibre waddings, open-cell foam or the like can also be included in the core.
Waist elastic elements 27,28 are applied along each side edge 2,5 of the base web 7. The waist elastic elements 27,28 are shown in Fig. 1 B as bands comprising multiple continuous elastic strands extending parallel to each other along the side edges 2,5 of the base web 7. The waist elastic elements 27,28 in Fig. 1 B may be provided in the form of a waist band formed from one or more plies of substantially non-elastic nonwoven material that is elasticized by one or more elongate elastic members, such as elastic threads or bands that are attached to the nonwoven material. The elastic waistband may be provided as a prefabricated component that is attached to the side edges 2,5, of the base web 7 and extend outboard of the side edges 2,5 of the base web 7 in the cross machine direction, CD. The waist elastic elements 27,28 may be made from elastic material that is stretched and attached in a tensioned or non-tensioned state to supporting elastic or inelastic webs. An elastic material that is attached to an inelastic web in a non-stretched state will have to be treated in order to activate the elasticity. Activation may be made by mechanical, thermal or chemical means or by irradiation. An elastic waist feature can alternatively be formed by attaching elastic members directly to an edge portion of the base web 7 or be formed from a folded waistband web comprising elastic elements in the fold. Furthermore, the waist elastic may comprise or consist of elastic web material such as elastic foam, film or nonwoven. The waist elastic is an optional component of the invention and may be omitted if desired. Moreover, the waist elastic may be arranged along only one of the side edges 2,5 of the base web 7 or may be intermittently applied as discrete segments of elastic along one or both side edges 2,5.
The waist elastic elements 27,28 in Fig. 1 B are shown to be arranged only in the vicinity of the side edges 2,5 of the base web 7. Further elastic elements may be placed in the area between the hourglass shaped hole 18 and the waist elastic elements 27,28. Such elastic elements would form body elastic in a finished boxer-type brief.
After all components have been added to the base web 7, the base web 7 is folded centrally in the machine direction MD along the dividing line 8. Paired side seams 30,31 are then formed in the CD between brief sections 32 to join the first and second continuous webs 1 ,4 in the CD. Subsequently, the brief sections 32 are cut off from the continuous base web 7 by CD cutting between two paired side seams 30,31 so that individual boxer-type briefs 433 are formed. Instead of using paired side seams 30,31 , the CD joins may be formed as single joins between a leading brief section 32 and a trailing brief section 32. The joins should have sufficient MD width to allow cutting to take place within the join. In this manner, two side seams are formed when the join is divided in the cutting step whereby one side seam is located on the leading brief section 32 and one side seam is located on the trailing brief section 32.
Side seams are often arranged in a disposable pant or brief to connect a front body portion to a rear body portion and to form a garment having a waist opening and leg openings. The side seams are intended to be arranged at the wearer's hips during use of the pant garment, such as the boxer-type briefs of the invention. The side seams are preferably designed so that they can withstand the tensile forces which arise when the briefs are being put on and are being worn, but such that they can be torn apart or opened in a controlled manner when the briefs are taken off or to check if the briefs need changing. In the latter instance, the side seams are preferably reclosable seams, as known in the art. Side seams may be formed by any suitable means known in the art such as adhesively, by ultrasonic bonding, by thermobonding or by stitching or needling. As the person skilled in the art is well aware, if thermobonding or ultrasonic bonding is being used, the base web material needs to comprise a sufficient amount of thermoplastic material in order to obtain sufficient bond strength. One example of a fully assembled boxer-type brief 433 that may be produced from a base web section such as the brief sections 32 formed in the Fig. A and 1 B process is shown in Fig. 4A. The Fig. 4A boxer-type brief is shown with a core pack 426. However, as explained herein, the invention is directed to all kinds of boxer-type briefs such as absorbent, non-absorbent or slightly absorbent boxer-type briefs. The boxer-type brief 433 in Fig. 4A has a front body portion 436, a rear body portion 437 and a crotch portion 438 between the front body portion 436 and the rear body portion 437. The boxer-type brief 433 has a waist edge 439 encircling a waist opening 440, two leg openings 441 ,442 and side seams 430,431 extending between the leg openings 5 441 ,442 and the waist opening 440 and connecting the front body portion 436 with the rear body portion 437.
Front and rear waist elastic 427,428 is arranged around the waist opening 440 The waist elastic 427,428 may be formed by a process such as that shown in Fig. 1 A and 1 B or may
10 be provided in the form of a separately produced waist band or in a different configuration as described herein. The elastic members are arranged around the waist opening 440 in a tensioned state such that they contract and gather the material around the waist opening 440 when they are allowed to relax, as shown in Fig. 4A. A boxer-type brief according to the invention need not have waist elastic with the configuration shown in Fig. 4A. The
15 waist elastic may be arranged on only one of the front body portion 436 and the rear body portion 437. The waist elastic may extend along only a part of the waist opening 440 such as along a central section of the front waist edge and/or the rear waist edge. Although not shown in the figure, body elastic may be arranged on the front body portion 436 and/or the rear body portion 437 in an area between the waist elastic 427,428 and the leg
20 openings 441 ,442.
As is seen in Fig. 4A, the finished boxer-type brief 433 has legs 443,444, the inner length, £>, of the legs 443,444 corresponding to the MD extension of the triangular pockets 16, 17 located on each side of the hourglass shaped hole 18 as shown in Fig. 1A. Accordingly,
25 the inner parts 445,446 of the legs 443,444 are formed from the triangular pockets 16, 17.
Accordingly, the inner parts 445,446 of the legs 443,444 are triangular gussets delimited by the folds 35 in the pockets and the CD edges 20, 21 at the open ends of the pockets 16, 17. The folds 35 are shown at reference number 435 in Fig. 4A. The gussets 445,446 are located on either side of the crotch portion 438 of the boxer-type brief 433 and will be
30 in contact with the inside of the wearer's thighs when the boxer-type briefs 433 are being worn. The gussets are oriented with their base along the attachments to the core pack 426 at each side of the crotch portion 438 and with narrowing width in a direction down along the inside of each leg 443,444 with the apex of each gusset being placed at the corresponding leg opening 441 ,442. Accordingly, the gussets expand the width of the legs
35 443,444 at the crotch portion 438 of the boxer-type briefs 433. The leg configuration shown in Fig. 4A is obtained when the core pack 426 or a supplementary material is attached to the triangular pockets 16,17 with bonding lines e-i , e2 arranged along the first and second edges, 20,21 , of the triangular pockets 16, 17 as shown in Figs. 1A and 3A. Accordingly, Fig. 4A illustrates the maximum inner leg length, i\, which may be obtained in a boxer-type brief according to the invention.
The core pack 426 that is attached on the inside of the boxer-type briefs 433 to cover up the hole 18 created during production of the boxer-type briefs 433 is visible on the outside of the boxer-type briefs 433 in the crotch portion 438. The core pack 426 is arranged with the backing layer facing towards the outside of the boxer-type briefs 433 and with the topsheet on the inside of the boxer-type brief. It is generally preferred that the backing layer is breathable such that perspiration and air may pass therethrough. The boxer-type brief 433 that is shown in Fig. 4B is identical to that in Fig. 4A, except that the attachment of the core pack 426 inside the brief 433 is made with broader band- shaped portions of the attachment area arranged along the first and second edges 20,21 , of the triangular pockets 16, 17, as shown in Fig. 3B. When a larger proportion of the triangular pockets 16,17 are bonded to the core pack 426, or other supplementary material, the inner leg length, i„ is shorter than when only a narrow bonding line on each side of the crotch portion 438 is used to join the supplementary material with the base web, as shown in Fig. 4A. Accordingly, Fig. 4B illustrates that the leg length of a boxer- type brief according to the invention is determined by the amount of bonding between the triangular pockets 16, 17 and the supplementary piece of material.
A further example of a fully assembled boxer-type brief 533 that may be produced from a base web section such as the brief sections 32 formed in the Fig. 1A and 1 B process is shown in Fig. 5. The Fig. 5 boxer-type brief is shown without an integrated absorbent core.
The boxer-type brief 533 in Fig. 5 has a front body portion 536, a rear body portion 537 and a crotch portion 538 between the front body portion 536 and the rear body portion 537. The boxer-type brief 533 has a waist edge 539 encircling a waist opening 540, two leg openings 541 ,542 and side seams 530,531 extending between the leg openings 541 ,542 and the waist opening 540 and connecting the front body portion 536 with the rear body portion 537.
Front and rear waist elastic 527,528 is arranged around the waist opening 540 as described for the boxer-type briefs in Figs. 4A and 4B.
As is seen in Fig. 5, the finished boxer-type brief has legs 543,544, the outer length, f0, of the legs 543,544 corresponding to the MD extension of the rectangular bond areas 9 that are formed in a process such as that shown in Figs. 1A and 1 B. The inner parts 555,556 of the legs 543,544 are formed from the triangular pockets 16, 17 that are formed on either side of the hour-glass shaped hole 18 in a process such as that in Figs. 1A and 1 B. The inner parts 555,556 of the legs 543,544 extend upward in Fig. 5 on either side of the crotch portion 538 of the boxer-type brief 533 and will be in contact with the inside of the wearer's thighs when the boxer-type briefs 533 are being worn. The inner parts 555,556 of the legs 543,544 are not visible from the outside of the boxer-type briefs 533 but are located on the inside of the boxer-type briefs 533 where they form raised barriers on each side of the crotch portion 538.
A supplementary material 550 that is attached on the inside of the boxer-type briefs 533 to cover up the hole created during production of the boxer-type briefs is visible on the outside of the boxer-type briefs 533 in the crotch portion 538. The supplementary material 550 may be an outer backing layer in a core pack, as disclosed herein or may be a piece of sheet material such as a nonwoven, a film, or laminate of two or more layers. The supplementary material 550 may be liquid permeable or liquid impermeable and may comprise an integral absorbent core or layer or may have an absorbent core or layer attached thereto on the inside of the boxer-type brief. It is generally preferred that the supplementary material 550 is breathable such that perspiration and air may pass therethrough. The leg configuration shown in Fig. 5 is obtained when the supplementary material 550 is attached to the triangular pockets 16, 17 in all of the overlapping portions of the supplementary material 550 and the triangular pockets 16, 17, as shown in Fig 3C. In the Fig. 5 configuration, the inner leg length, ¾, is zero which is the minimum length that may be obtained by the method of the invention.