WO2012087209A1

WO2012087209A1 - Method for making boxer-type briefs and boxer-type briefs produced according to the method

Info

Publication number: WO2012087209A1
Application number: PCT/SE2010/051463
Authority: WO
Inventors: Lucas BÄCK; Ulrika Carlson; Lennart Nilsson
Original assignee: Sca Hygiene Products Ab
Priority date: 2010-12-22
Filing date: 2010-12-22
Publication date: 2012-06-28

Abstract

A method for producing boxer-type briefs (330; 430), comprising the steps of: a) feeding a first continuous web (1) along a production path; b) feeding a second continuous web (4) along the production path; c) arranging the first and second continuous webs (1,4) in a side-by side configuration to form a base web (7) having a dividing line (8) extending in the machine direction (MD) between the first and second continuous webs (1,4); d) applying discrete rectangular sheets of material (9) to the base web (7) across the dividing line (8) at regular intervals along the production path; e) bonding the discrete rectangular sheets of material to the base web (7) by means of paired arrow-shaped bonds (10, 11) arranged with the points (12, 13) directed towards each other; f) intermittently forming pairs of arrow-shaped cuts (Ca) through the base web (7) and the discrete rectangular sheets of material (9) along the arrow-shaped bonds (10,11) in an area between the bonds (10, 11) leaving triangular pieces (9', 9") of the rectangular sheets of material (9) attached to the base web (7) by means of the arrow-shaped bonds (10,11) on each side of the arrow-shaped cuts (C3); g) attaching a supplementary material (20) over each pair of arrow-shaped cuts (Ca); and h) severing the base web (7) between the discrete rectangular sheets of material (9).

Description

METHOD FOR MAKING BOXER-TYPE BRIEFS AND BOXER-TYPE BRIEFS

PRODUCED ACCORDING TO THE METHOD

TECHNICAL FIELD

The invention pertains to a method for producing 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, and first and second parallel side edges in the machine direction and; 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, and first and second parallel side edges in the machine direction and; c) arranging the first and second continuous webs side-by side in the cross machine direction, CD, by aligning the first side edge of the second continuous web with the second side edge of the first continuous web thereby creating a base web having a dividing line extending in the machine direction, MD, between the first and second continuous webs; d) applying discrete rectangular sheets of material to the base web across the dividing line at regular intervals along the production path; e) bonding each discrete rectangular sheet of material to the base web by means of two arrow-shaped bonds being arranged in the machine direction, MD, with the points of the arrows being directed towards each other and being placed at the dividing line in the base web and at a distance from each other in the machine direction; f) intermittently forming pairs of arrow-shaped cuts through the base web and each discrete rectangular sheet of material along the arrow-shaped bonds in an area between the arrow-shaped bonds, whereby triangular pieces of the rectangular sheets of material that are attached to the base web by means of the arrow-shaped bonds are formed on each side of each pair of arrow-shaped cuts; g) attaching a supplementary material over each pair of arrow-shaped cuts; and h) severing the base web in the cross-machine direction between each discrete rectangular sheet of material.

The pair of arrow-shaped cuts may be connected by cuts in the machine direction so that a continuous cutting line is formed defining the contours of hourglass-shaped holes through the base web and the discrete rectangular sheets of material between the arrow- shaped bonds.

The method of the invention involves no separate folding of discrete web parts being made 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 taking place in the method according to the invention is longitudinal folding of the base web including the parts forming leg encircling portions of the boxer-type briefs.

The purpose of the supplementary material is to cover and mend the cuts in the base web and to create a continuous crotch portion without holes or slits in the finished boxer-type brief. The supplementary material may be attached to the base web on each side of the arrow-shaped cuts as seen in the cross machine direction. This means that the supplementary material will have a CD extension which is greater than the greatest CD distance between the arrow-shaped cuts. In the assembled boxer-type brief, the supplementary material will be attached on the inside of the front and back portions of the boxer-type brief.

Furthermore, the supplementary material may be attached to the triangular pieces of the rectangular sheet of material located on each side of the arrow-shaped cuts. Accordingly, in the area of the base web where the supplementary material is applied over the arrow- shaped cuts, the supplementary material may have a smallest width that is equal to the maximal MD distance between the arrow-shaped cuts or the supplementary material may have a width that is slightly larger than the maximal MD distance between the arrow- shaped cuts. The rectangular sheet of material has first and second edges extending in the cross machine direction and the supplementary material may be attached to the triangular pieces of the rectangular sheet of material with bonding lines arranged along the first and second edges in the cross machine direction. Alternatively, the supplementary material may be attached to the triangular pieces of the rectangular sheet of material over the full overlapping area between the supplementary material and the triangular pieces of material on each side of the arrow-shaped cuts or in a band-shaped area extending from the first and second edges of the rectangular sheet of material over only a portion of the triangular pieces of material in a direction towards the arrow-shaped cuts between the triangular pieces of material. In the fully assembled boxer-type brief, the edges of the attachment being located towards the arrow-shaped cuts between the triangular pieces of material will act as a 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 arrow-shaped cuts.

The greatest leg length is obtained when the attachments are formed by line bonds along the first and second CD edges of the rectangular sheet of material and the smallest leg length is obtained when the attachments are formed in the full overlapping area between the supplementary material and the triangular pieces of material on each side of the arrow-shaped cuts. All intermediate leg lengths may be obtained by letting the attachments extend further towards the arrow-shaped cuts, i.e. further towards the points of the triangular pieces of material. It is conceivable within the scope of the invention to arrange breakable bonds between the supplementary material and the triangular pieces of material in order to allow a wearer of the boxer-type brief or a care-taker to select a desired leg length.

Before severing the base web in the cross-machine direction between each of the discrete rectangular sheets of material, the base web may be folded along the dividing line with the triangular pieces of the discrete rectangular sheets of material being arranged between the first continuous web and the second continuous web.

If a closed boxer-type brief is desired, side seams may be created in the cross machine direction after folding of the base web. The side seams may be openable side seams or openable and reclosable side seams.

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. If an hourglass shaped hole is cut in the base web, 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 to enhance the impression of the boxer-type brief being ordinary 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 than covering layers and an 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, such as thermo-welding, ultrasonic welding, stitching and by means of adhesive, with adhesive bonding being preferred. The bonding may be made in any suitable pattern, to provide sufficient 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

Supplemental bonding of each the discrete rectangular sheet of material to the base web may be provided in an area located between the two arrow-shaped bonds. Such bonding may be in the form of discrete bonds or over all of the hourglass shaped area between the arrow-shaped bonds. The purpose of the supplemental bonding is to keep a cut-away hourglass shaped piece of the rectangular sheet of material and the base web attached to each other when removing them from the base web after having made hourglass shaped holes in the base web.

The cutting may be performed by means of any cutting method known in the art such as water jet or laser cutting. A particularly suitable means of forming the cut-out pieces is by using a rotary die cutter (RDC) as is well known in the art. An RDC comprises a rotating cutting roll having cutting edges on the peripheral surface. The cutting roll works against an anvil roll and cuts a web in the nip between the rolls. The cut-out pieces may then be removed from the base web in a conventional way such as by using suction means.

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 triangular gussets arranged on the inner parts of the leg portions of the briefs, i.e. the parts of the leg portions located closest to the crotch portion of the briefs. The gussets are formed from the rectangular sheets of material through bonding and cutting steps of the method according to the invention and provide the boxer-type briefs with increased leg-room.

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.

A "rectangular" piece of material is a material having a planar shape with four side edges arranged at right angles to each other. The terms "rectangular" and "rectangle" are used herein in a broad sense and include the special case when the rectangle is a square having side edges of equal length. The terms should be understood in a functional sense implying that the edges of the rectangular sheet of material may deviate slightly from a perfectly straight line, for instance by being somewhat ragged or by being cut along an undulating line, e.g. in a zigzag pattern. The corners of the rectangular sheet of material may have a slightly rounded shape as long as the side edges are arranged generally perpendicular to each other.

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 1A 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;

Figures 2A shows a portion of a production web in the method according to the invention; Figure 2B shows a portion of a production web in the method according to the invention;

Figure 2C shows a portion of a production web in the method according to the

invention;

Figure 3A shows a boxer-type brief made according to the method of the invention; Figure 3B shows a variant of the boxer-type brief in Figure 3A; and

Figure 4 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 disclosed herein.

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 a side-by side configuration in the cross machine direction, CD, together forming a base web 7 having a dividing line 8 extending in the machine direction, MD, between the first and second continuous webs 1 , 4 as shown in Fig. 1A. The first and second continuous webs 1 , 4 are brought together by aligning said first side edge 5 of said second continuous web 4 with said second side edge 3 of said first continuous web 1. In the resulting base web 7, the first side edge 2 of the base web 7 is the first side edge 2 of the first continuous web 1 and the second side edge 6 of the base web 7 is the second side edge 6 of the second continuous web 4. The two parts of the base web 7 are not connected along the dividing line 8. In Fig. 1A, the base web 7 is shown with a small gap, such as a gap of up to and including 100 millimeters, extending along the dividing line 8 between the first and second continuous webs 1 ,4. However, the first and second continuous webs 1 ,4 may be placed edge-to- edge without departing from the invention. 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 part of a chassis in a boxer-type brief and is commonly incorporated in 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 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 to one or both side edges 2,6 of the base web 7 at a later stage in the production process.

After forming the base web 7 by aligning the first and second continuous webs 1 ,4 with each other, discrete rectangular sheets of material 9 are applied to the base web 7 across the dividing line 8. The discrete rectangular sheets of material 9 are placed on the base web 7 at regular intervals along the production path. The discrete rectangular sheets of material 9 are placed on the base web 7 in those areas of the base web 7 that will form crotch portions in the finished boxer-type briefs. Accordingly, the spacing between the discrete rectangular sheets of material 9 corresponds to the MD extension of one brief.

Suitable materials for the discrete rectangular sheets of material 9 are those disclosed for the first and second continuous webs 1 ,4. The rectangular sheets of material 9 will form inner parts of the leg hoops in the finished boxer-type briefs and will be in contact with the inside of a wearers thighs when the briefs are worn. Accordingly, the material in the rectangular sheets of material 9 is preferably selected to be soft and comfortable against the skin of the wearer.

The discrete rectangular sheets of material 9 are subsequently bonded to the base web 7. Each discrete rectangular sheet of material 9 is bonded to the base web 7 by means of two arrow-shaped bonds 10, 1 1 that are arranged with the points 12, 13 of the arrows 10, 1 1 being directed towards each other in the machine direction, MD. As can be seen in Fig. 1A, the arrow-shaped bonds 10, 1 1 are placed with the points 12, 13 of the arrows at the dividing line 8 in the base web 7 and at a distance, d, from each other in the machine direction, MD. The arrow-shaped bonds 10, 1 1 may be made by any suitable method as known in the art such as by adhesive, ultrasonical bonding, thermo-bonding, stitching, etc. The bonds may be continuous line bonds or may consist of multiple discrete bonds such as point bonds, intermittent lines, etc. as known in the art. The arrow-shaped bonds 10,1 1 may be supplemented by discrete bonds 14 to provide attachment between the discrete rectangular sheets of material 9 and the base web 7 in the area between the arrow- shaped bonds 10, 1 1. The provision of such supplemental bonds may be advantageous at a later stage in the process when the material between the arrow-shaped bonds 10, 1 1 is removed from the base web 7 as will be described in the following.

After attachment of the discrete rectangular sheets of material 9, adhesive is applied to the base web 7 at each discrete rectangular sheet of material 9 in an attachment area 15 having a window 16 for the arrow-shaped bonds 10, 1 1. 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 15 or may be applied in different amounts and different patterns in different parts of the attachment area 15 as exemplified by Figs 2A-2C. By way of example, it may be desirable to use more adhesive or a stronger adhesive in the narrow CD parts, e-,, e₂, of the attachment areas 15 which extend on each side of the two arrow-shaped bonds 10, 1 1 as this adhesive will provide the only attachment between the core pack and the base web 7 in the area of the base web 7 that will be located in the crotch portion of the assembled boxer-type brief.

Depending on the size and configuration of the core pack or other supplementary material to be applied to the attachment area 15, the shape and size of the attachment area 15 may be different from those shown in Fig. 1A.

After application of the adhesive in the attachment area 15, hour-glass shaped crotch pieces 17 are cut out between the arrow-shaped bonds 10, 1 1 at each rectangular sheet of material 9. The cut comprises two opposite arrow-shaped cut sections C_a extending generally in the cross machine direction, CD and two opposite straight cut sections C_s extending in the machine direction, MD. The cut is made through the base web 7 and the rectangular sheet of material 9, leaving an hour-glass shaped hole 18 in the base web 7 and the rectangular sheet of material 9. The order of the process steps does not have to be as shown in Fig. 1A. Accordingly, the cut-out step may be performed before application of the adhesive in the attachment area 15. Moreover, the formation of hourglass shaped holes 18 is an optional feature of the invention as it is sufficient to make the arrow-shaped cut sections C_a in order to obtain the three-dimensional shaping of the crotch portion of the finished boxer-type brief. When the crotch pieces 17 have been cut out, a core pack 20 is applied to each attachment area 15. The core pack 20 covers the hour-glass shaped hole 18 and extends in the CD towards the side edges 2,6 of the base web 7. The core pack 20 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.

According to the invention, the supplementary material or a core pack 20 constituting a supplementary material is attached to the triangular pieces 9', 9" of the rectangular sheets of material 9 that remain on each side of each hourglass shaped hole 18 after the crotch pieces 17 have been removed. In order to completely cover the hole 18 in the base web, the core pack or other supplementary material may have a smallest width that is equal to the maximal MD width of the hourglass shaped hole 18 or the core pack 20 may have a width that is slightly larger than the maximal MD width of the hourglass shaped hole 18.

Figs. 2A-2C show portions of a base web 7 having differently configured attachment areas 15 for attaching a core pack 20 or some other supplementary material over the hour-glass shaped hole 18 in the base web 7. The figures illustrate that the attachment area 15 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 herein with reference to Figs. 3A, 3B and Fig. 4. With particular reference to Fig. 2A, the adhesive attachment area 15 comprises a plurality of discrete adhesive portions with narrow band shaped portions arranged along the CD edges of the rectangular piece of material and further discrete adhesive areas positioned on either side of the hour-glass shaped hole 18 in the CD. A section through the base web 7 in Fig. 2A is taken 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 connected to each other. Accordingly, the triangular pieces 9', 9" of the rectangular sheet of material are attached to the first continuous web 1 and to the second continuous web 4 along the arrow-shaped bonds 10, 1 1 so that an open pocket is formed between the triangular pieces 9', 9" and the continuous webs 1 ,4 on each side of the hourglass shaped hole 18. Furthermore, the supplementary piece of material indicated as a core pack 20 in Fig. 2A is attached to the triangular pieces 9', 9" by means of the parts of the adhesive area 15 that are arranged along first and second edges βι , e₂ of the rectangular piece of material to form an accordion-like structure on each side of the hourglass shaped hole 18. In the finished boxer-type brief, the accordionlike structure will be unfolded to create legs hanging down from the crotch portion of the brief. The rectangular sheets of material 9 have first and second edges e_u e₂, extending in the cross machine direction, CD, and the core pack 20 is shown to be attached to the triangular pieces 9', 9" of the rectangular sheet of material 9 with bonding lines arranged along the first and second edges e₂, in the CD. Alternatively, the core pack 20 or other supplementary material may be attached to the triangular pieces 9', 9" over the full overlapping area between the core pack 20 and the triangular pieces, 9', 9", on each side of the hourglass shaped hole 18 as shown in Fig. 2C or in a band-shaped area extending from the first and second edges, e _t e₂, of the rectangular sheet of material 9 over only a portion of the triangular pieces of material, pieces 9', 9", in a direction towards the hourglass shaped hole 18 between the triangular pieces of material 9', 9", as shown in Fig 2B. In the fully assembled boxer-type brief, the inner edges 15', 15" of the attachment area 15 being the CD edges of the attachment area 15 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 20 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 and 1 B and the smallest leg length is obtained when the attachments are formed in the full overlapping area between the core pack 20 and the triangular pieces of material pieces 9', 9". All intermediate leg lengths may be obtained by letting the attachments extend further towards the hole 18, i.e. further towards the points 12, 13 of the arrow-shaped bonds 10, 1 1.

A "core pack", as used herein is a separately produced component that is integrated with the base web 7 and includes an absorbent core 21 enclosed between a topsheet 22 and a backing layer 23. The core pack 20 may be adhesively attached to the base web 7, as shown in Figs. 1 B and 2A-C. However, any other suitable bonding means such as thermobonding or ultrasonic bonding may be used. Although the core pack 20 is shown in Fig. 1 B to have a rectangular shape, the core pack may take other forms such as hourglass shape, trapezoidal shape, etc. Furthermore, the core pack 20 may be larger or smaller than the core pack 20 shown in Fig. 1 B and may be asymmetrically placed in the CD direction in relation to the dividing line 8 as long as it completely covers the hour-glass shaped hole 18 in the base web 7.

The various components included in the core pack 20 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 22 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 23 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 23 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 23 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 23 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 21 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 24,25 are applied along each side edge 2,6 of the base web 7. The waist elastic elements 24,25 are shown in Fig. 1 B as bands comprising multiple continuous elastic strands extending parallel to each other along the side edges 2,6 of the base web 7. The waist elastic elements 24,25 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 2,6, of the base web 7 and extend outboard of the side edges 2,6 of the base web 7 in the cross machine direction, CD. The waist elastic elements 24,25 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 2,6 of the base web 7 or may be intermittently applied as discrete segments of elastic along one or both side edges 2,6.

The waist elastic elements 24,25 in Fig. 1 B are shown to be arranged only in the vicinity of the side edges 2,6 of the base web 7. Further elastic elements may be placed in the area between the rectangular sheets of material 9 and the waist elastic elements 24,25. 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 26,27 are then formed in the CD between brief sections 28 to join the first and second continuous webs 1 ,4 in the CD. Subsequently, the brief sections 28 are cut off from the continuous base web 7 by CD cutting between two paired side seams 26,27, so that individual boxer-type briefs 30 are formed. Instead of using paired side seams 26,27, the CD joins may be formed as single joins between a leading brief section 28 and a trailing brief section 28. 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 28 and one side seam is located on the trailing brief section 28.

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. The boxer-type brief 30 in Fig. 1 B is shown with the waist elastic elements 24,25 in an extended state and is seen from the waist opening 31 that is formed by the side edges 2,6 of the base web 7 towards the leg openings 32,33 that are formed by the dividing line 8 in the base web 7. W

18

One example of a fully assembled boxer-type brief 330 that may be produced from a base web section such as the brief sections 28 formed in the Fig. 1 A and 1 B process is shown in Figs. 3A and 3B. The Figs. 3A and 3B boxer-type brief is shown with a core pack 320. However, as explained herein, the invention is directed to all kinds of boxer-type briefs 5 such as absorbent, non-absorbent or slightly absorbent boxer-type briefs.

The boxer-type brief 330 in Figs. 3A and 3B has a front body portion 334, a rear body portion 335 and a crotch portion 336 between the front body portion 334 and the rear body portion 335. The boxer-type brief 330 has a waist edge 337 encircling a waist

10 opening 331 , two leg openings 332,333 and side seams 326,327 extending between the leg openings 332,333 and the waist opening 331 and connecting the front body portion 334 with the rear body portion 335.

Front and rear waist elastic 324,325 is arranged around the waist opening 331 The waist 15 elastic 324,325 may be formed by a process such as that shown in Fig. A and B or may 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 331 in a tensioned state such that they contract and gather the nonwoven material around the waist opening 331 when they are allowed to relax, as shown in Figs. 3A and 3B. A boxer- 20 type brief according to the invention need not have waist elastic with the configuration shown in Figs. 3A and 3B. The waist elastic may be arranged on only one of the front body portion 334 and the rear body portion 335. The waist elastic may extend along only a part of the waist opening 331 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

25 arranged on the front body portion 334 and/or the rear body portion 335 in an area below the waist elastic 324,325.

As is seen in Fig. 1 B and in Figs. 3A and 3B, the finished boxer-type brief has legs 338,339, the inner length, of the legs 338,339 corresponding to the MD extension of the

30 portions of the triangular pieces 9', 9" of the rectangular sheet of material 9 that are not attached to the core pack 20. Hence, the inner length, i_h of the legs 338,339 is equal to the distance between the parts of the attachment area 5 arranged along the first and second edges e₂ of the rectangular sheet of material 9 and the points 12,13 of the arrow-shaped bonds 10,1 1 , as shown in Fig. 1 A and in Fig 2A and 2B. The inner parts

35 340,341 of the legs 338,339 are formed from the triangular pieces 9', 9" of the rectangular sheets of material 9 that are left on either side of the hour-glass shaped hole 18 that is created by the cutting step in Fig. 1A. The inner parts 340,341 of the legs 338,339 form triangular gussets on either side of the crotch portion 336 of the boxer-type brief 330 and will be in contact with the inside of the wearer's thighs when the boxer-type briefs 330 are being worn. The gussets are oriented with their base along the attachments to the core pack 320 at each side of the crotch portion 336 and with narrowing width in a direction down along the inside of each leg 338, 339 with the apex of each gusset being placed at the corresponding leg opening 332,333. Accordingly, the gussets expand the width of the legs 338,339 at the crotch portion of the boxer-type briefs 330.

The leg configuration shown in Fig. 3A is obtained when the core pack 320 or a supplementary material is attached to the triangular pieces 9', 9" of the rectangular sheet of material 9 with bonding lines arranged along the first and second edges, e_{1 t} e₂, of the rectangular sheet of material 9 as shown in Figs 1A and 2A. Accordingly, Fig. 3A illustrates the maximum inner leg length, ¾, which may be obtained in a boxer-type brief according to the invention.

The core pack 320 that is attached on the inside of the boxer-type briefs 330 to cover up the hole 18 created during production of the boxer-type briefs 330 is visible on the outside of the boxer-type briefs 330 in the crotch portion 336. The core pack 320 is arranged with the backing layer facing towards the outside of the boxer-type briefs 330 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 330 that is shown in Fig. 3B is identical to that in Fig. 3A, except that the attachment of the core pack 320 inside the brief 330 is made with broader band- shaped portions of the attachment area arranged along the first and second edges e-,, e₂, of the rectangular sheets of material 9, as shown in Fig. 2B. When a larger proportion of the triangular pieces 9', 9" of the rectangular sheets of material 9 are bonded to the core pack 320, or other supplementary material, the inner leg length, t„ is shorter than when only a narrow bonding line on each side of the crotch portion 336 is used to join the supplementary material with the base web, as shown in Fig. 3A. Accordingly, Fig. 3B illustrates that the leg length of the boxer-type brief is determined by the amount of bonding between the triangular pieces 9', 9" of the rectangular sheets of material 9 and the supplementary piece of material. A further example of a fully assembled boxer-type brief 430 that may be produced from a base web section such as the brief sections 28 formed in the Fig. 1 A and 1 B process is shown in Fig. 4. The Fig. 4 boxer-type brief is shown without an integrated absorbent core.

The boxer-type brief 430 in Fig. 4 has a front body portion 434, a rear body portion 435 and a crotch portion 436 between the front body portion 434 and the rear body portion 435. The boxer-type brief 430 has a waist edge 437 encircling a waist opening 431 , two leg openings 432,433 and side seams 426,427 extending between the leg openings 432,433 and the waist opening 431 and connecting the front body portion 434 with the rear body portion 435.

Front and rear waist elastic 424,425 is arranged around the waist opening 431 as described for the boxer-type briefs in Figs. 3A and 3B.

As is seen in Fig. 4, the finished boxer-type brief has legs 438,439, the outer length, i₀, of the legs 438,439 corresponding to the MD extension of the parts of the rectangular sheet of material 9 that are left between the CD edges of the rectangular sheet of material 9 and the points 12, 13 of the arrow-shaped bonds 10,1 1 , as shown in Fig. 1A. The inner parts 440,441 of the legs 438,439 are formed from the triangular pieces 9', 9" of the rectangular sheets of material 9 that are left on either side of the hour-glass shaped hole 18 that is created by the cutting step in Fig. 1 A. The inner parts 440,441 of the legs 438,449 are found extending upward in Fig. 4 on either side of the crotch portion 436 of the boxer-type brief 430 and will be in contact with the inside of the wearer's thighs when the boxer-type briefs 430 are being worn. The inner parts 440,441 of the legs 438,449 are not visible from the outside of the boxer-type briefs 430 but are located on the inside of the boxer- type briefs 430 where they form raised barriers on each side of the crotch portion 436. A supplementary material 442 that is attached on the inside of the boxer-type briefs 430 to cover up the hole 18 created during production of the boxer-type briefs is visible on the outside of the boxer-type briefs 430 in the crotch portion 436. The supplementary material 442 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 442 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 442 is breathable such that perspiration and air may pass therethrough.

The leg configuration shown in Fig. 4 is obtained when the supplementary material 442 is attached to the triangular pieces 9', 9" of the rectangular sheet of material 9 in all of the overlapping portions of the supplementary material 442 and the triangular pieces of material 9', 9", as shown in Fig 2C. In the Fig. 4 configuration, the inner leg length, ¾, is zero which is the minimum length that may be obtained by the method of the invention.

Claims

1. A method for producing boxer-type briefs (330; 430) characterised in that the method comprises the steps of: a) feeding a first continuous web (1 ) along a production path in a machine direction (MD) said first continuous web (1 ) having a cross machine direction (CD) transverse to said machine direction (MD) and first and second parallel side edges (2,3) in said machine direction (MD); b) feeding a second continuous web (4) along said production path in said machine direction (MD) said second continuous web (4) having a cross machine direction (CD) transverse to said machine direction (MD) and first and second parallel side edges (5,6) in said machine direction (MD); c) arranging said first and second continuous webs (1 ,4) side-by side in said cross machine direction (CD) by aligning said first side edge (5) of said second continuous web (4) with said second side edge (3) of said first continuous web (1 ) thereby creating a base web (7) having a dividing line (8) extending in the machine direction (MD) between said first and second continuous webs (1 ,4); d) applying discrete rectangular sheets of material (9) to said base web (7) across said dividing line (8) at regular intervals along said production path; e) bonding each said discrete rectangular sheet of material to said base web (7) by means of two arrow-shaped bonds (10, 1 1 ) being arranged in the machine direction (MD) with points (12, 13) of said arrow-shaped bonds (10,1 1 ) being directed towards each other and being placed at said dividing line (8) in said base web (7) and at a distance from each other in the machine direction (MD); f) intermittently forming pairs of arrow-shaped cuts (C_a) through said base web (7) and each said discrete rectangular sheet of material (9) along the full extension of said arrow-shaped bonds (10, 1 1 ) in an area between said arrow-shaped bonds (10, 1 1 ); whereby triangular pieces (9',9") of said rectangular sheets of material (9) that are attached to said base web (7) by means of said arrow-shaped bonds (10,1 1 ) are formed on each side of each said pair of arrow-shaped cuts (C_a); g) attaching a supplementary material (20) over each pair of arrow-shaped cuts (C_a); and h) severing said base web (7) in said cross-machine direction (CD) between each said discrete rectangular sheet of material

2. Method according to claim 1 , wherein said pair of arrow-shaped cuts (C_a) are connected by straight cuts (C_s) in the machine direction (MD) whereby hourglass-shaped holes (18) are formed through said base web (7) and each said discrete rectangular sheet of material (9) between said arrow-shaped bonds (10, 1 1 ).

3. Method according to claim 1 or 2, wherein said supplementary material (20) is attached to said base web (7) on each side of said hourglass shaped hole (18) as seen in the cross machine direction (CD).

4. Method according to claim 1 , 2 or 3, wherein said supplementary material (20) is attached to said triangular pieces (9',9") of said rectangular sheet of material (9) remaining on each side of said arrow-shaped cuts (C_a).

5. Method according to claim 4, wherein said rectangular sheet of material (9) has first and second edges (e^ e₂) extending in the cross machine direction (CD) and said supplementary material (20) is attached to said triangular pieces (9',9") of said rectangular sheet (9) of material with bonding lines arranged along said first and second edges (e-i , e₂) in the cross machine direction (CD).

6. Method according to any one of the preceding claims, wherein said base web (7) is folded along said dividing line (8) with said discrete rectangular sheets of material (9) being arranged between said first continuous web (1 ) and said second continuous web (4), the folding step being carried out before severing said base web (7) in said cross- machine direction (CD) between each said discrete rectangular sheet of material (9).

7. Method according to claim 6, wherein side seams (26,27) are created in the cross machine direction (CD) after folding of said base web (7).

8. Method according to claim 7, wherein said side seams (26,27) are reclosable side

5 seams.

9. Method according to any one of the preceding claims, wherein said supplementary piece of material (20) comprises or consists of a material selected among: nonwovens, films and laminates.

10

10. Method according to any one of the preceding claims, wherein said supplementary material (320) comprises an absorbent core.

1 1. Method according to claim 10, wherein said supplementary material is comprised in a 15 core pack (320), said core pack comprising a topsheet layer, a backsheet layer and an absorbent core between said topsheet layer and said backsheet layer and having side edges extending in the cross machine direction.

12. Method according to claim 1 1 , wherein said core pack is provided with elastic

20 elements arranged in the cross machine direction along each side edge of said core pack.

13. Method according to any one of the preceding claims, wherein said supplementary material is attached to said base web (7) by means of adhesive (15).

25 14. Method according to any one of the preceding claims, wherein supplemental bonding (14) of each said discrete rectangular sheet of material to said base web (7) is provided in an area located between said two arrow-shaped bonds.

15. Method according to any one of the preceding claims, wherein waist elastic (324,325) 30 is applied along at least one side edge (2,6) of said base web (7).

16. Boxer-type briefs (330; 430) produced according to any one of the preceding claims.

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