KR100244561B1 - Zero scrap absorbent core formation process and products derived from web-based absorbent materials - Google Patents

Abstract

The present invention discloses a multilayer absorbent core having a front ear section, a crotch section and a rear ear section, and a method of making such a multilayer absorbent core, wherein the machine direction length of the crotch section is defined by the front ear section and the rear. Equal to the sum of the machine direction lengths of the ear sections, the angles and radii forming the transition band from the crotch width to the ear width are the same, and the core is suitable for use in absorbent articles. The method provides a web (10) of a single absorbent core material from a roll, wherein the web has a parallel straight longitudinal side edge; Continuously moving the web of absorbent core material in a machine direction; One or more complete patterned strips 14 having a repetitive hourglass shape, and one of the parallel straight longitudinal side edges of the web and the end of the complete patterned strip 14 of the web of absorbent core material. Continuously cut longitudinally into the web section with first (16) and second (18) side cut pieces with straight edges defined by opposed non-linear longitudinal edges with a pattern corresponding to one of the directional edges. (12); Continuous side multi-layer composite strips 24 are oriented continuously with respect to the strips 14 of the complete pattern such that the ear and crotch sections of the pieces overlap with the strips 14 of the complete pattern to overlap. To form; The composite strip 24 is continuously cut laterally at predetermined intervals to form a separate multilayer absorbent core 26.

Description

ZERO SCRAP ABSORBENT CORE FORMATION PROCESS AND PRODUCTS DERIVED FROM WEB-BASED ABSORBENT MATERIALS}

The present invention relates to shaped or shaped absorbent cores made of several pieces or layers of absorbent material obtained from web based materials useful for absorbent articles, such as diapers, adult incontinence briefs, sanitary napkins and the like. The present application also relates to a method of making such a molded or contoured absorbent core which essentially eliminates the flakes produced in the manufacture of the molded absorbent core.

Incontinence products, such as disposable diapers, not fabrics, have typically used absorbent structures comprising entangled fibers, ie nonwoven fibrous webs. These webs inhale aqueous fluids, including released body fluids, by absorption mechanisms that absorb the fluids by the fibrous material itself, and in particular by suction mechanisms that trap and distribute the fluids through capillary gaps between the fibers. These webs often include low density layers that are loosely filled with absorbent fibers such as carded cotton webs, air-laid cellulose fibers, pulverized wood pulp fibers, and the like.

Fibrous webs used in such absorbent articles also often include some absorbent gelling materials called 'hydrogels', 'superabsorbents' or 'hydrocolloid' materials, which usually store large amounts of released body fluids. For example, U.S. Pat. Use of the material is disclosed. Indeed, the development of thinner diapers has been a direct result of using thinner absorbent cores, which in particular has the advantage of the ability of the particulate absorbent gelling material to absorb large quantities of released aqueous body fluids when used with a fiber matrix. See, for example, US Pat. No. 4,673,402 to Weisman et al. On June 16, 1987 and US Pat. No. 4,935,022 to Lash et al. On June 19, 1990 (dense and bulky). A dual layer core structure is disclosed comprising a fiber matrix and a particulate absorbent gelling material useful for making diapers.

These particulate absorbent gelling materials are less than expected on the market for their ability to hold large amounts of fluids, for example urine. Representative examples of such particulate absorbent gelling materials are slightly crosslinked polyacrylates. Like many other absorbent gelling materials, these slightly crosslinked polyacrylates comprise a plurality of anionic (charged) carboxyl groups bonded to the polymer backbone. These charged carboxyl groups allow the polymer to absorb aqueous body fluids as a result of osmotic pressure.

In addition to osmotic pressure, capillary-based absorbency is also important in many absorbent products, including diapers. Capillary forces can be sensed in a variety of everyday phenomena as illustrated by paper towels that suck up spilled liquids. Capillary absorptivity can provide good performance for fluid capture and suction rates, i.e., the ability of the aqueous fluid to move away from the initial contact point. Indeed, the dual-layer absorbent core structures such as Weisman et al. And Lash et al. Used the fiber matrix as a primary capillary vehicle to transport the initially captured aqueous fluid through the absorbent core, It can be absorbed and retained by particulate absorbent gelling material disposed in the layer or zone of the core. The fiber structures disclosed in the patents of Weisman et al. And Lash et al. Are manufactured through air-laying techniques. Such techniques include air laying fibers into molded cavities on a shielded drum to shape the core and to control the amount of material used for the core. Excessive overflow of the shaped cavity is removed by the lid roll and recovered to the incoming air stream. Absorbent gelling material (AGM) is added to the air stream along with the fiber material. The process changes the screen, laydown drum shape to form a number of other shapes. Thus the shape of the material is formed by 'shaping' the fibers into the molded cavity. The process provides a shape without cutting, which in turn generates the least amount of pieces.

Another absorbent material that can potentially provide capillary fluid transport can be an open cellular polymeric foam. If suitably manufactured, the open cellular polymeric foam can provide the capillary fluid capture, transport and storage properties required for a high performance absorbent core for absorbent articles such as diapers. Absorbent products containing such foams may have desirable wet integrity, provide suitable conformity throughout the entire life of the product, and avoid changing shape during use. In addition, absorbent articles containing such foam structures can be more easily manufactured on a commercial scale. For example, an absorbent diaper core may be designed to simply stamp from a continuous foam sheet and have significantly greater integrity and uniformity than an air-laid fibrous absorbent core containing particulate absorbent gelling material.

In addition to absorbency and ease of manufacture, another potential desirable property of such foams is the ability to produce shaped or contoured absorbent cores having various shapes, fluid absorbents, and the like. Fibrous absorbent cores containing particulate gelling material are often molded or shaped to provide a particularly hourglass form. See, for example, dual layer absorbent core structures such as Weisman et al.

Molded or contoured absorbent cores made from open cellular foam materials having particularly desirable fluid transport properties are disclosed in US Pat. No. 5,147,345, issued to Young et al. On September 15, 1992. The absorbent core, such as Young, includes a fluid storage / redistribution component that includes an open cellular polymeric foam that is hydrophilic and flexible, as well as a fluid capture / distribution component that may be a fiber or foam substrate. 9, such as Young et al., Has one such shaped or shaped article having an hourglass fluid capture / distribution layer 73 comprising fibrous absorbent material over an hourglass fluid redistribution / storage layer comprising an open cell absorbent foam; A core with an outline is disclosed. FIG. 2 also discloses having a smaller rectangular fluid capture / distribution layer 51 comprising fibrous absorbent material over a larger hourglass fluid redistribution / storage layer 52 that includes an open cellular polymeric foam. It is.

It is not a problem to prepare shaped or contoured absorbent cores or layers from foam materials, including those disclosed in the above patents. The hourglass foam layers shown in FIGS. 9 and 2 of Young et al. Are typically made from a single rectangular foam piece. These rectangular foam pieces can be notched, cut or otherwise cut to make hourglass pieces. In carrying out this process, a significant amount of useless foam pieces can be produced. In fact, in the formation of hourglass foam pieces, it has been found that as much as 15-25% of the total foam material can be left as useless pieces.

In addition, single hourglass foam pieces can cause some problems in the comfort of absorbent articles in which an absorbent foam core is used. In the case of higher modulus absorbent foam, the single hourglass core may be less flexible and less flexible. This is especially the case in the crotch region of the absorbent core made from a single hourglass type absorbent foam layer. Thus, it would be desirable to be able to produce absorbent cores molded or shaped from polymeric foams that (1) reduce the occurrence of foam fragments and (2) provide greater flexibility and flexibility, particularly in the crotch region.

Conventional product designs for straight roll stock, molded absorbent core structures made from web materials have generally produced a significant amount of pieces that must be discarded or recycled during the fabrication process. Designs that form shapes using multiple rolls of materials of varying widths are sometimes difficult to perform, especially when using very narrow material webs. Large rolls of narrow webs are very difficult to fabricate and are difficult to process into absorbent products.

Attempts have been made to reduce the amount of flake material produced during the fabrication of patterned articles obtained from continuous webs. For example, US Pat. No. 4,760,764 to Jonckheere et al. And EP 0539 032 Al of Johnson & Johnson have continuously cut a continuous web of material into an annular pattern, each having a patterned longitudinal and straight edge. A manufacturing method is disclosed in which the amount of waste material is reduced, providing two strips. The strips are laterally arranged to form two layered central portions that align the tabs and then join together in an overlapping manner to create the rim contour of the final disposable absorbent article. These products are limited to a single design structure with only one layer in the ear or plate area and only two layers in the central portion. This pattern can be repeated on top of itself, but the number of layers in the central portion will be twice that of the layers present in the outer molded portion. This arrangement is potentially effective in terms of fluid absorption, but is less desirable in terms of hardness, flexibility, overall thickness, and crotch volume minimization.

US Patent No. 3,072,123 (Davis), issued Jan. 8, 1963, shows a number of adjacent wavy cut lines that form a nested shape that is further processed and made into an absorbent product. Since the patent essentially aims to produce a single structure from the nested shape, the outermost partial shape is useless, thus creating a piece of material. This approach differs from the attempts of the present invention to use essentially the entire shape as well as partially shaped pieces. US Patent No. 3,878,286 to April 15, 1975 (Jones) attempted to fabricate nested absorbent structures, but the outermost areas of the web containing only partial structures or shapes, such as in US Pat. No. 3,072,123, are useful. Lacking and thus creating a flake material. US Patent No. 4,862,574 (Seidy), September 5, 1989, illustrates a method for making panty protection products. Although the patent shows a pattern of repetitive cutting patterns or wave types, the pattern is transverse and not continuous in the machine or web direction. Thus, the attempt of patent 4,862,574 creates components other than the intention of the present invention to create a continuous pattern that produces a plurality of webs of product shape into a continuous web. The cutting pattern included in patent 4,862,574 creates partial structures, which do not provide utility for their respective inventions, as in the previously mentioned patents. US Pat. No. 3,527,221 to September 8, 1970 (Croon et al) shows a wave cutting pattern used to form the outer cover, body plate of a diaper. Although the fragmentation was minimally generated with this approach, it is not applied to the absorbent structure itself, which also does not include stratification of the separated structure as in the present invention.

U.S. Patent No. 5,102,487; 5,034,007; 4,595,441; And 5,330,598 disclose continuous strips of materials with repeating patterns, none of which seek to provide an absorbent core structure. In addition, none of the aforementioned patents contain two or more strips of material as in the present invention.

Furthermore, none of the prior art references has an absorbent core structure having a plurality of absorbent material layers in the crotch region and the 'ears' or plate portion, wherein the absorbent core structure is formed from a single web without generating fragments. Is not manufactured).

Accordingly, it is a primary object of the present invention to provide a method of making an absorbent core material from a single web of material such that 'no fragments are generated'.

It is another object of the present invention to provide a method of making an absorbent structure having at least two absorbent core material layers in both the crotch region and the 'ear' portion of the absorbent structure, from which the core structure is made from a single absorbent material web.

It is a further object of the present invention to provide a method for producing various absorbent core structures from a single absorbent material web having different forms, depending on the desired use of such absorbent cores.

Still another object of the present invention is to provide an absorbent core structure with improved absorbency and greater flexibility and flexibility for use in the manufacture of diapers, incontinence products and the like.

Although this specification concludes with the claims particularly pointed out and specifically claimed in the subject matter of the present invention, it is believed that the present invention will be better understood from the following description and drawings. In the drawings, like reference numerals refer to like elements.

1 is a perspective view illustrating a method of making an absorbent core of the present invention;

2 is a perspective view illustrating a variant of the method shown in FIG. 1;

3 is a perspective view illustrating another method of making the absorbent core of the present invention;

4 is a perspective view illustrating a variant of the method shown in FIG. 3;

5A-5D are top views of a single width absorbent material web showing a cut-out pattern according to one aspect of the first embodiment of the present invention with superimposed cut pieces;

6A and 6B are top views of a single width absorbent material web showing a cut-out pattern according to another aspect of the first or second embodiment of the present invention where the ends of the cut pieces are in contact;

7A and 7B are top views of a single width absorbent material web showing a cut-out pattern according to another aspect of the first or second embodiment of the present invention in which the cut pieces form a gap;

8A-8D are top views of a single width absorbent material web showing a cut-out pattern according to another aspect of the second embodiment of the present invention;

9 is a top view illustrating an absorbent core structure according to one aspect of the first embodiment of the present invention showing cut pieces superimposed in a fully overlapping fashion;

10 is a cross sectional view of the absorbent core structure of FIG. 9 taken along lines 9-9;

11 is a top view illustrating an absorbent core structure according to another aspect of the first or second embodiment of the present invention showing cut pieces superimposed in a partially overlapping fashion;

12 is a cross sectional view of the absorbent structure of FIG. 11 taken along lines 11-11;

FIG. 13 is a top view illustrating an absorbent structure in accordance with another aspect of the first or second embodiment of the present invention showing two cut pieces in an endless fashion;

14 is a cross sectional view of the absorbent core structure of FIG. 13 taken along lines 13-13;

15 is a top view illustrating an absorbent core structure according to another aspect of the first or second embodiment of the present invention showing two cut pieces in a form forming a gap;

FIG. 16 is a cross sectional view of the absorbent core structure of FIG. 15 taken along lines 15-15; FIG.

FIG. 17 illustrates another first or second embodiment of the present invention showing a first web cut-out partially cut to reveal two cut pieces in a partially peeled and end-facing format to further reveal a second major central web. Top view of an absorbent core structure according to another aspect;

FIG. 18 is a cross sectional view of the absorbent core structure of FIG. 17 taken along lines 17-17; FIG.

19 is a first or third embodiment of the present invention showing a first web cut-out partially stripped to reveal the second major central web and partially cut to reveal the two cut pieces in a gap-forming fashion; Is a top view of an absorbent core structure according to another aspect of;

20 is a cross sectional view of the absorbent core structure of FIG. 19 taken along lines 19-19;

Figure 21 is a top view of a cut-out pattern showing the relative shape and dimensions of the absorbent core of the present invention.

According to the invention, a single roll of absorbent material having a predetermined width is fed into a die cutter, for example a rotary knife, wherein one or more specific patterns are cut with the classification of intermittent dividing lines and the single web is in accordance with the product design. Separate into three or more individual webs. By designing cut-out patterns so that specific limitations are met as defined later, the various strips or pieces can be cut and aligned so that they exactly overlap and conform to the desired final core product.

The present invention not only provides a method for producing an efficient absorbent core material from a single roll of material, but also provides a product whose shape creates better conformity and which provides greater product flexibility and flexibility during wear due to multilayering. to provide. By using multilayering, the web thickness can be minimized, thus maximizing the amount of material used to make the core and reducing shipping and storage costs. Furthermore, the present invention provides a method for producing such absorbent core material without substantial accumulation of flake material, thereby eliminating the need for additional steps of discarding or regenerating excess material.

In order not to generate fragments, the following limitations should be maintained in forming the shape of the core material as illustrated in FIG. 21:

(1) The most important limitation is the longitudinal distance of the crotch and ear section. Referring to FIG. 21, the distance b = a + c, where a is the distance from the front edge of the front core ear to the middle point of the conversion band between the front core ear and the core crotch, and the distance b is the front core and core crotch The distance from the middle point of the conversion band between the core crotch and the rear core ear to the middle point of the conversion band between the core crotch and the rear core ear, and the distance c is the distance from the middle point of the conversion band between the core crotch and the rear core ear to the rear core ear end). ;

(2) the front ear width is equal to the rear ear width; And

(3) The conversion band between ear parts and crotch should be symmetrical.

In a first embodiment of the invention, a single width web of absorbent material is fed from a roll to a die cutter, one main web cut-out having the desired pattern of the final product, and two formed along the lateral edges of the web. Two trim pieces (the pieces are moved to the upper position of the complete pattern strip). According to one aspect of this embodiment, the two cut pieces are placed on top of the complete pattern strip in a fully overlapping form, wherein the core has three layers of absorbent material in the entire crotch portion and two layers of absorbent material in the core ears. ). In one manifestation, two cut pieces are placed in a partial overlapping form with the core having three layers in the central longitudinal portion of the crotch region, the two layers in the lateral longitudinal portion in the crotch region and the two layers in the core ear.

In a second aspect, the two cut pieces are in the same plane. In the first specification, two cut pieces of absorbent material are placed in an 'end-to-end' fashion in which the core has two layers of absorbent material in the entire crotch region and two layers of absorbent material in the core ear. In the second specification, two cut pieces are formed in a 'shape' form in which the core has a single layer of absorbent material in the central longitudinal region of the crotch and two layers of material in the lateral longitudinal region of the crotch and core ears. Release. For the purposes of the present invention, the term 'facing end' means that the cut pieces come in contact along the straight edges of the pieces. The term 'forming a gap' means that the straight edges of the cut pieces do not touch and do not overlap. On the one hand, the two cut pieces can be separated from the web and oriented together with the straight longitudinal rims arranged next to each other to form the first desired pattern and then the complete pattern strip can subsequently be superimposed on the cut pieces.

In a second embodiment of the present invention, a single width sheet of absorbent material is fed from a roll to a die cutter to provide two main webs arranged side by side along a common central rim, the tabs of one web being the other web ( Each web is then staggered to exactly correspond to the notch of the final product); Two cut pieces are formed along the lateral edges of the web, where the cut pieces are sandwiched between two web cut-outs in a fully or partially overlapping form, so that the crotch portion has four layers of absorbent material and core ear Providing a core with three layers of absorbent material, or sandwiched in the form of 'end-to-end' or 'gap' to have three or two layers of absorbent material in the crotch portion and three layers of absorbent material in the core ear Go to the position to provide the core with. Alternatively, the cut pieces may be moved to a position above or below the two main webs, either partially or completely overlapped, or in a 'facing' or 'shaping' form.

In a third embodiment of the invention, a single width absorbent material web is fed from a roll to a die cutter, one main web cut-out having the desired pattern of the final product, and two formed along the lateral edges of the web. Providing a cut piece, wherein the cut pieces are twisted or rotated 180 ° before being superimposed on the complete pattern strip. In this embodiment, the top side of the side cut piece faces the top side of the complete pattern strip. As in the first and second embodiments above, the two side cut pieces are placed on top of the complete pattern strip in a fully overlapping or partially overlapping fashion, with the core having three layers of absorbent material in the crotch and two layers at the core ear. Provide a first aspect of the third embodiment with an absorbent material of or alternatively provide two aspects of this embodiment by placing the two cutting strips in the same plane, such as in the form of 'end-to-end' or 'gap'. You may.

In another embodiment of the present invention, a sheet of absorbent material of a single width is fed from a roll to a die cutter to provide two main webs arranged side by side along a common center rim, the tabs of one web being the other web ( Each web is then staggered to exactly correspond to the notch of the final product); Two cut pieces are formed along the lateral edges of the web, where these cut pieces are sandwiched between two web cut-outs in a fully or partially overlapping form such that four layers of absorbent material and core ears are placed in the crotch portion. To provide a core with three layers of absorbent material, or sandwiched in a 'facing' or 'gap' form with two or three layers of absorbent material in the crotch and three layers of absorbents at the core ear Move to a location that provides a core with the material. On the one hand, the cut pieces may be moved to the upper position of the two main webs in a partially or completely overlapping form, or in a 'facing end' or 'shaping' form.

The structures of the present invention will be disclosed in connection with the use of absorbent cores in disposable diapers, adult incontinence products, sanitary napkins, and the like; It goes without saying that the possible use of the structure of the invention is not limited to only the absorbent core structure or the above-mentioned disposable products. Hereinafter, 'disposable absorbent product' refers to any product that absorbs and receives body secretions such as urine, stool, menstrual blood, blood, and the like. More specifically, the term is placed on or adjacent to the wearer's body to absorb and receive various secretions released from the body, and also to discard any waste that is disposed of after one use (ie not washed or otherwise restored or reused). Refers to a product. In a preferred aspect of the present invention, disposable absorbent core structures are used in diaper products. As used herein, the term 'diaper' refers to underwear commonly used by infants and incontinent adults and is worn around the wearer's lower torso. In general, disposable diapers include a liquid permeable topsheet, a liquid impermeable backsheet associated with the topsheet, and an absorbent core structure disposed between the topsheet and the backsheet.

The present invention relates to a process for producing an absorbent core structure, in particular an absorbent core structure which does not 'sculpt' and thus eliminates the step of discarding or regenerating excess material.

Typically, the web of absorbent material is controlled by applying energy to the web. This is accomplished by pulling the web at various locations through nips, S wraps, and the like, which in turn drives other rolls including idlers, tracking devices, and the like. Because of the hysteresis of some absorbent materials, which may be very viscoelastic, it is important to keep the web material under minimal strain, and preferably the strain should not exceed about 1%.

According to the invention, each of the rolls in the core-making apparatus is driven independently so that the propulsion energy is independent of the web material. If all rolls are driven at the same speed, no deformation is imparted to the web, and in order to maintain sufficient web tension, the speed of each roll should not be more than 1% faster than the preceding roll. Even if all rolls are driven at the same speed, there is still a position where the web is slightly deformed. Deformation is imparted when the web passes over the roll and twists during step movement. The strain can be maintained under 1% as it passes over the roll by appropriately selecting the roll diameter. Knowing the web thickness, the strain can be fixed at 1% and the minimum roll diameter can be calculated by the following equation:

d = 2t (1-e) / e

Where t is the web thickness and e is the strain.

The diameter should be at least 'd'. The torsion roll is calculated by calculating the web's strain as the web progresses through the helix during torsion (the strain at the edge is fixed at 1% or less for the minimum distance h) and the different path lengths of the center of the web. It is maintained under 1% by selecting a minimum height of. The spiral through which the web travels (illustrated in figure) is also measured by the angle α of the torsional roll. The angle α is determined by the formula:

α = arcsin (c / d)

The above equation only applies if the web path is perpendicular to the roll when twisted. The height h of the torsion roll is determined by the formula:

h = [n (core length) + b -pd] / 2

Where b is the distance between the rolls.

n is an independent variable and can be any integer. This represents the number of cores in which the cut pieces are moved back up. n should be chosen such that h is at least h initially determined.

Do not hold the cutting roll in place. They can rotate so that the cut pieces are properly tracked when placed on top of the main web. The placement of the roll and the vertical axis around which it rotates is very important for proper web adjustment and tracking. The web needs to be perpendicular to the roll and will track towards the position.

While the centerline of each of the cut pieces is twisted, the centerline must remain tangential and perpendicular to each roll and new (or preceding) web path. The rolls are sized and spaced to maintain this limit. This defines the roll separation distance b.

The axis of the torsion roll that rotates around is the same as the centerline of the cut piece. In this way, the geometric relationship between the cutting piece and the torsional roll is always maintained (at the inflow side of the roll). This is somewhat similar to the Fife unit, a tracking device in the web handling industry. The present system uses drive rolls (Fife uses idlers); Using three rolls (Fife uses four); The roll diameter (Fife uses approximately 3 'diameter rolls) and the vertical axis of rotation of the tracking unit are different.

As illustrated in FIG. 1, a uniform web 10 of absorbent material supplied from a single roll (not shown) is in a desired pattern by a rotating die 12 or other means in accordance with one embodiment of the present invention. The cut provides a complete pattern of cutouts 14, first cut pieces 16 and second cut strips 18. After cutting the web into three patterned webs (one main pattern cutout and two cut pieces), the cutout 14 of the main pattern is continued in the same plane as the original web 10 In doing so, the first outer cut piece 16 is twisted and guided by a first raised drive roll 20 which is inclined relative to the centerline of the machine such that the piece 16 is superimposed on the complete pattern cutout 14. do. By a longer path through which the first cut piece 16 moves compared to the cutout 14 of the complete pattern, the first cut piece 16 moves in the machine direction and aligns with the cutout 14 of the complete pattern. do. Immediately before joining the complete cutout 14 and the first cut piece 16, the adhesive bonding material may be applied to the top surface of the cutout 14 of the complete pattern or the bottom surface of the first cut piece 16, or both. It is also possible to apply these layers both continuously or intermittently to temporarily bond these layers together during processing. Other bonding methods known in the art, such as thermal bonding, may also be used instead of the adhesive material.

The second cut piece 18 undergoes a transformation (mirror image) similar to the first cut piece 16 in the second rising roll 22. The bonded web 24 continues in the machine direction and moves to the cutting process and the accelerated conveyor to have three layers of absorbent material in the crotch portion 28 of the separated core structure 26 and the ' The ears 30 are separated into a separate core structure 26 having two layers of absorbent material.

As illustrated in FIG. 2, a uniform web 40 of absorbent material having a width slightly wider than the web shown in FIG. 1 is obtained by first cutting strip 42, first complete pattern strip 44, and second complete pattern. Cut into strip 46 and second cut strip 48. After cutting the web 40 into four patterned strips (two cutting strips and two complete patterned strips), the complete patterned strip and the second cutting strip are continuously in the same plane as the original web 40. While the first cutting strip 42 is laid, the first rising roll inclined relative to the machine centerline such that the first cutting strip 42 is superimposed on the strip 44 of the first complete pattern or the strip 46 of the second complete pattern. It is twisted and guided by 50. By the longer length that the first cutting strip 42 moves relative to the strip 44 of the first complete pattern, the first cutting strip moves in the machine direction and aligns with the strip 44 of the first complete pattern. Immediately before joining the first cut strip 42 and the first cut strip 42, an adhesive bonding material (not shown) may be applied to the top surface of the strip 44 of the complete pattern or the first cut cut strip 42. It may also be applied to the bottom, or both, continuously or intermittently to temporarily bond these layers together during processing.

As the first cutting strip 42 is superimposed on the strip 44 of the first complete pattern, the second cutting strip 48 undergoes a transformation (mirror image) similar to the first cutting strip 42 on the second rising roll 52. In which the first joined web 54 continues to move in the machine direction. As the second cutting strip 48 is superimposed on the strip 44 of the first complete pattern, the strip 46 of the second complete pattern is lifted by the third rising roll 56 and subsequently the first and A second cutting strip 42 and 48 is disposed between the first and second complete patterns of strips 44 and 46, respectively, to form a second bonded web 64 so as to form a second joined web 64. Superimposed on). The composite structure 58 containing the two complete patterns of strips and two cutting strips continues to move to the cutting process (not shown) and to the accelerated conveyor so as to be placed in the crotch portion 62 of the separated core structure 60. , Separated into a separate core structure 60 having three or four layers of absorbent material and three layers of absorbent material at the 'ears' 64 of the core structure 60.

3 and 4 show the first cutting strip as the web 80 moves in the machine direction and the first cutting strip 82 and the second cutting strip 84 are lifted by the lifting rollers 85 and 87, respectively. 82) and the second cutting strip 84 are twisted at 180 ° so that when they are superimposed on the strip 86 of the complete pattern, the top surface of the cutting strips faces the top surface of the strip 86 of the complete pattern. Similar to FIGS. 1 and 2. As shown in FIG. 4, the second complete pattern of strips 88 is lifted by the third rising roll 93 and superimposed on the joined web 92 to form the first complete pattern of strips 86 and the second complete pattern. A composite web 94 is formed containing first and second cutting strips 82 and 84 disposed between the strips 88 of the pattern, respectively. The composite web 94 (FIG. 4) and 95 (FIG. 3) are separated core structures 96 (FIG. 4) and 97 (each having a crotch portion 98 and an ear portion 99), respectively. Cut to 3).

5A-5D illustrate a uniform web 100 having two longitudinal cuts providing a first cut strip 102, a complete pattern of strip 104, and a second cut strip 106. 5B illustrates a first cut strip 102 superimposed on a complete pattern of strips, and FIG. 5C illustrates a first cut strip 102 and a second cut strip 106 overlapping to form a joined web structure 108, A second cutting strip 106 is shown superimposed on the complete pattern of strips. 5D shows the cut apart core structure 110.

As illustrated in FIGS. 6A and 6B, a uniform web 120 having a slightly narrower width than the webs shown in FIGS. 5A-5D is formed by the strip 122, the first cut piece 124 and the second cut piece 126 of a complete pattern. ) And used to provide the core structure of FIGS. 5A-5D, except that the first cut piece 124 and the second cut piece 126 provide web structures 128 joined adjacent to each other along a straight edge. Assemble similarly. The bonded web has two layers of absorbent material in the crotch portion 130 of the core structure and two layers of absorbent material in the 'ear' portion 132 of the core structure. Although the present embodiment is illustrated as having two cut pieces adjacent to each other, when the two cut pieces are 'stacked' on top of the cutout 146 of a complete pattern, they are much narrower so that they are preferably spaced apart rather than adjacent shapes. It is also within the concept of the present invention to provide a much thinner first and second cut piece 142, 144 using web material 14, respectively. This concept is illustrated in Figures 7a and 7b.

8A-8D show a uniform web 150 of absorbent material having a first complete pattern of cutouts 152, a second complete pattern of strips 154, a first cut piece 156 and a second cut piece formed simultaneously in a staggered form ( 158) illustrates a second or fourth embodiment of the present invention. In this embodiment, the first cut piece 156 and the second cut piece 158 are assembled to have the first cut piece 156 and the second cut piece 158 'stacked' on top of the strip 152 in a complete pattern. A complete patterned composite 152 is provided, wherein the first cut piece 156 and the second cut piece 158 are adjacent to each other along a straight edge. With the first complete pattern strip 152 and the two cut pieces 156, 158 in place, the second major pattern strip 154 is aligned with the first complete pattern strip 152 to make the first cut. Piece 156 and second cut piece 158 further provide a desired pattern adjacent to each other along a straight border, which are sandwiched between the first complete pattern strip 152 and the second complete center strip 154 so that all Provide a combined web structure 160 in which the components are arranged in the desired design format. The bonded web 160 is then cut laterally and separated into separate core structures having three layers of absorbent material at the crotch portion of the core structure and three layers of absorbent material at the 'ears' of the core structure.

Embodiments of the present invention and the various forms of each of the above embodiments are better understood with respect to FIGS. 9 to 18, wherein FIGS. 9 and 10 show that the first and second cutting strips 170 and 172 each have a complete pattern of strips. Illustrates an aspect of the first embodiment of the invention where the second cut piece 172 extends over the full width of the crotch portion 174 over the top of 176 and overlies the first cut piece 170. As can be seen in FIG. 10, the resulting core structure 178 has three layers of absorbent material in the crotch portion 174 of the structure 178 and two layers of absorbent material in the 'ears' 180. .

In another form illustrated in FIGS. 11 and 12 of the present invention, the first and second cutting strips 190 and 192 respectively extend only a partial width of the strip 198 of the complete pattern in the crotch portion 194. . As shown in FIG. 12, the resulting core structure 196 has three layers of absorbent material in the central portion of the crotch portion, while the outer rim and 'ears' 204 of the crotch portion have two layers of absorbent material. .

As illustrated in FIGS. 13 and 14, the first and second cutting strips 210 and 212 are placed on top of the strip 214 of the main pattern in adjacent form to provide two layers of absorbent material to the crotch portion 218. And a core structure 216 having two layers of absorbent material at the 'ears' 220. In a further form of this aspect of the invention, the first cut piece 210 and the second cut piece 212 lie in parallel planes, but are spaced apart rather than adjacent to each other. This form is shown in FIGS. 15 and 16.

In another embodiment of the invention illustrated in FIGS. 17 and 18, the first cut pieces 230 and the second cut pieces 232 are identical to the way in which the cut pieces are laid on the strip of the complete pattern illustrated in FIGS. 13 and 14. The top of the strip 234 in a complete pattern in a contiguous manner. However, in this embodiment, the second complete pattern of strip 236 includes two cut pieces 230, such that the cut pieces are sandwiched between the cutout 234 of the first major pattern and the cutout 236 of the second major pattern. 232 is placed on top. As can be seen in FIG. 18, the resulting core structure 238 has three layers of absorbent material in the crotch portion 240 of the structure and three layers of absorbent material in the 'ears' 242. As a further form of the third embodiment of the present invention, the first cut piece 230 and the second cut piece 232 lie in parallel planes, but two layers are formed in the central crotch portion and spaced apart rather than adjacent to each other. In the part three layers are formed. This form is illustrated in FIGS. 19 and 20.

While particular embodiments of the invention have been illustrated and disclosed, those skilled in the art will recognize that various other changes and modifications can be made without departing from the spirit and scope of the invention.

While various forms of embodiments of the invention have been specifically illustrated in FIGS. 1-20, other forms may be apparent to those skilled in the art. For example, in FIGS. 9-16, the first and second cut pieces may be placed on either side of the strip of complete pattern, or the first and second cut pieces may be placed on the opposite side of the strip of complete pattern. In addition to the shapes illustrated in FIGS. 17-20, both cut pieces may be placed on the outer surface of either complete patterned strip, or the first cut piece may be placed on the outer surface of one complete patterned strip, and the second cut piece may be placed on another complete piece. It can be placed on a strip of patterns. Furthermore, two cut pieces may be placed on opposite sides of one complete pattern of strips and the other complete pattern of strips facing one side of the first complete pattern of strips. Obviously, the cut pieces of the above shapes may be placed in a 'overlapping', 'adjacent' or 'shaping' form as described above. Accordingly, all such changes and modifications that fall within the scope of the invention are intended to be included within the scope of the appended claims.

According to the invention it is possible to produce absorbent core materials which are free of fragments.

Claims (22)

In a multilayer absorbent core for use in an absorbent article, The multi-layer absorbent core has one or more individual absorbent layers forming the shape of the core and the first and second partial overlapping over the layers with the same length as the one or more individual absorbent layers forming the shape of the core. Two separate cut pieces of absorbent material forming an absorbent layer, wherein the non-linear side edges of the first partially absorbent material layer coincide with the corresponding first non-linear side edges of the core. And the non-linear side edges of the second partial absorbent layer are aligned with the second non-linear side edges of the core, the multilayer absorbent core having a front ear, a crotch section and a rear ear. The machine direction length of the crotch section is equal to the sum of the machine direction lengths of the front ear and the rear ear, and the length of the front core ear Is defined as the longitudinal length of the absorbent core from the front edge of the anterior core ear to the midpoint of the first transition band between the anterior core ear and the core crotch section, the length of the crotch section being the first length between the anterior core ear and the core crotch section. The longitudinal length of the absorbent core from the midpoint of the first transition band to the midpoint of the second transition band between the core crotch section and the rear core ear is defined as the length of the rear core ear is the second length between the core crotch section and the rear core ear. And a longitudinal length of the absorbent core from the midpoint of the conversion band to the rear edge of the rear core ear, wherein the first and second conversion bands are symmetrical to each other. The method of claim 1, An absorbent core in which longitudinal side edges opposite the non-linear side edges of the first and second partial absorbent material layers overlap longitudinally along a centerline of the core. The method of claim 1, An absorbent core, wherein the linear side edges opposite the non-linear side edges of the first and second partial absorbent material layers border longitudinally along the centerline of the core. The method of claim 1, Wherein the linear side edges opposite the non-linear side edges of the first and second partial absorbent material layers are spatially spaced apart longitudinally along the centerline of the core. The method of claim 1, Absorbent core, wherein the absorbent article is a disposable diaper or incontinence brief. The method of claim 1 wherein the multilayer absorbent core is Providing, from the roll, a web of single absorbent core material having parallel straight longitudinal side edges; Longitudinally extending the web of absorbent core material into a web section having one or more strips of absorbent material in the shape of a repetitive hourglass and two separate trim pieces forming the first and second partial absorbent material layers; Cutting continuously with the first and second partial absorbent material layers each opposing non-linear of a strip of absorbent material having an hourglass shape that repeats with one of the parallel straight longitudinal side edges of the web. Has a straight longitudinal border defined by the longitudinal border); The first and second partial absorbent material layers are continuously oriented with respect to the at least one absorbent core strip having an hourglass shape that repeats to overlap on top of the at least one absorbent core material strip to form a continuous multilayer composite strip. And subsequently subsequently cutting the composite strip laterally at predetermined intervals to form a separate multilayer absorbent core, wherein The core has a front ear, a crotch section and a rear ear, wherein the machine direction length of the crotch section is equal to the combined machine direction length of the front ear and the rear ear, The length of the front core ear is defined as the longitudinal length of the absorbent core from the front edge of the front core ear to the midpoint of the first transition band between the front core ear and the core crotch section, the length of the crotch section being the front core ear and The longitudinal length of the absorbent core from the midpoint of the first transition band between the core crotch sections to the midpoint of the second transition band between the core crotch section and the rear core ears, the length of the rear core ears being defined by the core crotch section. The longitudinal length of the absorbent core from the midpoint of the second transition band between the posterior core ears to the rear edge of the posterior core ears, wherein the first and second translation bands are symmetric with each other, Absorbent core. The method of claim 6, An absorbent core in which longitudinal side edges opposite the non-linear side edges of the first and second partial absorbent material layers overlap longitudinally along a centerline of the core. The method of claim 6, An absorbent core bordered along a centerline of the core is a linear side edge opposite the non-linear side edges of the first and second partial absorbent material layers. The method of claim 6, Wherein the linear side edges opposite the non-linear side edges of the first and second partial absorbent material layers are spatially spaced apart longitudinally along the centerline of the core. The method of claim 6, Absorbent core, wherein the absorbent article is a disposable diaper or incontinence brief. The method of claim 2, And the first and second partial absorbent material layers overlap to correspond to the full width of the crotch section. The method of claim 2, And the first and second partial absorbent material layers overlap less than the full width of the crotch section. The method of claim 7, wherein And the first and second partial absorbent material layers overlap to correspond to the full width of the crotch section. The method of claim 7, wherein And the first and second partial absorbent material layers overlap less than the full width of the crotch section. The method of claim 1, The multilayer absorbent core comprises first and second separate absorbent material layers forming the shape of the core and two separate absorbent material cut pieces forming the first and second partially absorbent material layers, At this time The cut pieces are coincidentally overlapped in the first individual absorbent material layer forming the shape of the core, and the second partial absorbent material layer forming the shape of the core is the first and second portions. An absorbent core forming a multilayer absorbent core having an absorbent material upper layer coincidently overlapping on a layer of absorbent material to form the shape of the core, at least one intermediate layer of cut pieces of absorbent material and an absorbent material lower layer forming the shape of the core. . The method of claim 1, An absorbent core, wherein the absorbent material is a foamed absorbent material. In an absorbent article comprising a multilayer absorbent core, the multilayer absorbent core has at least one individual absorbent material layer forming the shape of the absorbent core and the same length as the at least one individual absorbent material layer forming the shape of the core. Two separate cut pieces of absorbent material forming a first and a second partially absorbent material layer overlying this layer, wherein the non-linear side edges of the first partially absorbent material layer are formed of the core. Arranged to coincide with a corresponding first non-linear side edge, wherein the non-linear side edge of the second partial absorbent material layer is arranged to coincide with the second non-linear side edge of the core, and the multilayer absorbent core Has an anterior ear, a crotch section and a rear ear, the machine direction length of the crotch section being in the machine room of the front ear and the rear ear The length of the front ear is defined as the longitudinal length of the absorbent core from the front edge of the front core ear to the midpoint of the first transition band between the front core ear and the core crotch section, the length of the crotch section Is defined as the longitudinal length of the absorbent core from the midpoint of the first transform band between the front core ear and the core crotch section to the midpoint of the second transform band between the core crotch section and the rear core ear, Wherein said first and second conversion bands comprise multilayer absorbent cores symmetric to each other. The method of claim 17, An absorbent article, wherein the linear side edges opposite the non-linear side edges of the first and second partial absorbent material layers overlap longitudinally along the centerline of the core. The method of claim 17, An absorbent article, wherein the linear side edges opposite the non-linear side edges of the first and second partial absorbent material layers border longitudinally along the centerline of the core. The method of claim 17, Wherein the linear side edges opposite the non-linear side edges of the first and second partial absorbent material layers are spatially spaced apart longitudinally along the centerline of the core. The method of claim 18, And the first and second partial absorbent material layers overlap to correspond to the full width of the crotch section. The method of claim 18, And the first and second partial absorbent material layers overlap less than the full width of the crotch section.