MXPA00005238A - Methods of bonding materials, especially materials used in absorbent articles - Google Patents
Methods of bonding materials, especially materials used in absorbent articlesInfo
- Publication number
- MXPA00005238A MXPA00005238A MXPA/A/2000/005238A MXPA00005238A MXPA00005238A MX PA00005238 A MXPA00005238 A MX PA00005238A MX PA00005238 A MXPA00005238 A MX PA00005238A MX PA00005238 A MXPA00005238 A MX PA00005238A
- Authority
- MX
- Mexico
- Prior art keywords
- materials
- absorbent
- bonding
- joining
- elements
- Prior art date
Links
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Abstract
Methods of bonding materials used in the manufacture of articles, including, but not limited to, absorbent articles such as sanitary napkins, pantiliners, tampons, absorbent interlabial devices, diapers, incontinence devices, wipes, and the like are disclosed. There are numerous aspects of the disclosed methods. In one aspect, the method involves bonding through incompatible materials during the process of making a composite structure comprising several materials. In another aspect, improvements are made that allow the method to be used to bond through relatively thick materials (e.g., materials having a thickness of greater than or equal to about 4 mm). In another aspect, the methods are provided with the ability to create a virtually unlimited number of bonding patterns in the materials to be bonded. In still another aspect, the methods of bonding utilize a compression step to improve bond formation. In still another aspect, methods of bonding that utilize a step of slitting a material through which the bonds are made are disclosed.
Description
METHODS FOR JOINING MATERIALS, ESPECIALLY MATERIALS USED IN ABSORBENT ITEMS
FIELD OF THE INVENTION
The present invention relates generally to methods of bonding materials for use in absorbent articles, although the techniques described herein may be used to join materials used in other types of articles. In preferred embodiments, the present invention relates to methods that are used in the manufacture of absorbent articles such as sanitary napkins, pantyhose, absorbent interlabial articles, diapers, incontinence articles, and the like.
BACKGROUND OF THE INVENTION
Absorbent items such as sanitary napkins, panties, tampons, absorbent interlabial articles, disposable diapers, incontinence products, and bandages designed to absorb and retain fluid and other discharges from the human body and to prevent body and clothing stains. In the manufacture of absorbent articles, it is generally necessary to join the components that will form the article to form the final product. Typical methods for bonding such materials include adhesives, heat and / or pressure and ultrasonic. Some materials, however, can not be joined by these typical joining techniques due to structural integrity or composition. One type of material is absorbent foam materials made from high internal stage emulsions, (or "HIPE" foams) such as those described in US Patent 5,260,345 published on behalf of DesMarais, et al. on November 9, 1993; U.S. Patent 5,268,224 published in the name of DesMarais, et al. on December 7, 1993; and U.S. Patent 5,387,207 published on behalf of Dyer, et al. on February 7, 1995. Such materials typically have low tensile strength and / or low structural integrity. It is difficult to bond such materials using adhesives because their structural integrity is often not as strong as the adhesive bond. As a result, only portions of these materials that are in direct contact with the adhesive will remain attached to other materials. The rest of the material will quickly separate from the material to which it was attached. Such materials can not be bonded using heat bonds because such foams are thermal hardening polymers. Once they are formed, they can not be recast. Instead, when the heat is applied to such foam materials, they will carbonize instead of melting and flowing, which is necessary for heat bonding. Such a foam material also can not be pressurized because the thermal hardening foam material has no ability to flow and be melted under pressure. U.S. Patent 4,473,611 entitled "Porous Polymer Material Containing a Reinforced and Heat Sealable Material" published on behalf of Haq on September 25, 1984 discloses an earlier effort to bond materials to a highly porous polymeric material prepared by polymerization of an emulsion high internal stage. The Haq reference reveals in providing such material with the ability to form heat seal by incorporating thermoplastic fibers, particle material or foraminous therein. An article such as a cleaning towel is formed by sandwiching the modified porous polymer material between two heat-sealable substrates, and heat sealing the first and second substrate to the heat-sealable reinforcement material in the highly porous intermediate polymeric material. The method of making the porous polymeric material described in the Haq patent, however, requires the addition of thermoplastic material. This complicates the process of making the porous polymeric material. Other types of materials used in the manufacture of absorbent articles often comprise thermoplastic materials. U.S. Patent 4,854,984 entitled "Method of Dynamic Mechanical Union and Apparatus" published on behalf of Ball, et. on August 8, 1989 discloses a method and apparatuses for mechanically and dynamically joining a plurality of sheets feeding through a pressure-biased grip between a pair of rolls, at least one of which has a pattern in relief in the same. The method described in the patent of Ball, et al. It has been used with great commercial success. Still, the search to improve the methods of bonding materials has continued. Thus, there is a need for improved methods of bonding materials, especially those used in absorbent articles. For example, a need exists for an improved method of bonding materials for use in absorbent articles that can not be joined by known joining techniques, and in particular by a method that does not require adding thermoplastic materials to the material in benefit to join other materials. in the same. A need also exists for a method of joining through relatively thin materials during the manufacture of absorbent articles. In addition, there is also a need for joining methods that can create a virtually unlimited number of bonding patterns in the materials that will be bonded.
BRIEF DESCRIPTION OF THE INVENTION
The present invention is generally directed to methods of bonding materials for use in absorbent articles, although the techniques described herein may also be used to bond materials used in other types of articles. All of these uses of the methods described herein may be considered to be within the scope of the present invention. In preferred embodiments, the present invention relates to such methods that are used in the manufacture of absorbent articles such as sanitary napkins, pantyhose, tampons, absorbent interlabial articles, diapers, incontinence articles, and the like. There are numerous aspects of the present invention. In one aspect, the present invention relates to a method of bonding through incompatible materials during the process of making a composite structure comprising several materials. As used herein, the term "incompatible materials" refers to materials that find it difficult to join other materials using conventional bonding techniques. In another aspect, the present invention relates to improvements that allow the method to be used to bond through relatively thin materials (eg, materials having a thickness greater than or equal to about 2, 3, or 4 mm). In another aspect, the present invention relates to joining methods that can create a virtually unlimited number of bonding patterns in the materials to be bonded. In still another aspect, the present invention relates to joining methods that use a compression step to improve the bonding formation. In yet another aspect, the present invention relates to joining methods that use a step to cut a material by which the joints are made. It should be understood that the modalities described in the specification are expressed in terms of preferred embodiments so that throughout this specification is not excessive. It should be understood that the present invention does not intend to be limited to such modalities. It should also be understood that aspects of the methods described herein may be combined in a single process, or may be used individually, or in any desired combination. Additionally it should be understood that the inventors consider that all such uses or combinations of these aspects potentially comprise patentable inventions separately, and that the scope of such inventions is intended to be as broad as the prior art allows. The scope of such inventions is intended to be limited solely by the claims, and not by the preferred embodiments described herein. The aspect of the method of bonding through incompatible materials preferably comprises the steps of: (a) providing a material that has at least a degree of incompatibility with the use of conventional bonding techniques, the incompatible material having a first bond , a first surface, and a second surface; (b) providing at least one other material that can be joined that is greater than the first unible; (c) covering at least a portion of the first and second surfaces of the incompatible material with at least one material having a joint that is greater than the first unit; and (d) the bonding material having a top joint covering at least a portion of the first surface of the material compatible with the material having the largest unit covering at least a portion of the second surface of the incompatible material using unions that penetrate the incompatible material. In this aspect of the methods described herein, the incompatible material preferably comprises an absorbent material. In a particularly preferred embodiment, the incompatible material comprises a thermally hardening polymeric absorbent foam material. The material that has more unit can comprise a number of appropriate materials, including, but not limited to: one or more webs of material, a layer of glue, a silicone cover. In a particularly preferred embodiment in which the incompatible material comprises a thermally hardening polymeric absorbent foam material, the material having more unit comprises a nonwoven web. The present invention also provides a method of forming materials, particularly compressible materials, such as absorbent materials, for use in absorbent articles such as sanitary napkins, panties, tampons, absorbent interlabial articles, diapers, incontinence articles, cleaning towels, and the like. In this aspect of the present invention, a binding pattern is printed on the incompatible compressible material to isolate a portion of the incompatible material from the rest of the incompatible material and the isolated portion in a different form. The forming aspect of the method described herein may involve one or more folding steps. Numerous other uses of the methods described herein will also become apparent.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with the claims particularly pointing out and distinctively claiming the subject matter that is intended as part of the present invention. It is believed that the invention will be better understood with the following description which is taken in conjunction with the accompanying drawings in which: Figure 1 is a perspective view of a network composed of material comprising an incompatible absorbent foam material which It will be joined and formed into an absorbent tube for a sanitary napkin using the method of the present invention.
Figure 2 is a perspective view of an apparatus used to form the absorbent material in the composite network shown in Figure 1 in particulate material in an optional, but preferred step of making the absorbent tube. Figure 3 is a partially fragmented perspective view of the composite network shown in Figure 1 after it has been fed by the apparatus shown in Figure 2 and the incompatible absorbent foam material has been formed into particle material. Figure 4 is a perspective view of the composite network shown in Figure 3 after the side margins have been folded in an optional first folding operation. Figure 5 is a schematic perspective view of the composite network shown in Figure 3 after it has been folded in a second optional folding operation. Figure 6 is a schematic perspective view of the composite network shown in Figure 5 after portions of it have been joined. Figure 7 is a simplified cross-sectional view of the network shown in Figure 6 taken through the bonding sites along line 7-7 of Figure 6. Figure 8 is a schematic perspective view of a one-pass mode of the method that is used to join the tube of the absorbent material for a sanitary napkin, with the patterned roll shown in a simplified manner. Figure 9 is a simplified fragmentary schematic view showing a nip gauge material between a patterned roll and an anvil roll in which the patterned roll has no compressible material around its raised element. Figure 10 is a simplified fragmentary schematic view showing a gauging material in the grip between a patterned roll and an anvil roll in which the patterned roll has a compressible material around its raised element. Figure 11 is a perspective view showing the surface of an anterior dynamic bond roll with intermittent load bearing members therein. Figure 12 is a perspective view showing the surface of a patterned roll used in an embodiment of the method of the present invention with continuous load bearing members therein. Figure 13 is a perspective view of a composite sanitary napkin having a tube of absorbent material on the side that is in contact with the body, which was joined and formed by the method of the present invention. Figure 14 is a schematic view showing an alternative path of joining two incompatible materials using the method of the present invention. Figure 15 is a perspective view of an absorbent interlabial article that is bonded and formed by the method of the present invention. Figure 16 is a perspective view of a variation of the method of the present invention that is used to make an interlabial article. Figure 17 is a partially fragmented plan view of the sanitary napkin which is made by the method of the present invention. Figure 18 is a schematic cross section of a portion of the sanitary napkin shown in Figure 17.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a method of bonding materials for use in absorbent articles, although the techniques described herein may be used to join materials used in other types of articles. In preferred embodiments, the present invention relates to such a method which is used in the manufacture of absorbent articles such as sanitary napkins, panties, tampons, absorbent fabric articles, diapers, incontinence articles, cleaning towels, and the like. There are numerous aspects of the present invention. In one aspect, the present invention relates to a method of bonding through incompatible materials during the process of making a composite structure comprising several materials. As used herein, the term "incompatible materials" refers to materials that find it difficult to join other materials using conventional bonding techniques. In another aspect, the present invention relates to improvements that allow the method to be used to bond through relatively thin materials (eg, materials having a thickness greater than or equal to about 2, 3, or 4 mm). In another aspect, the present invention relates to joining methods that can create a virtually unlimited number of bonding patterns in the materials to be bonded. In still another aspect, the present invention relates to joining methods that use a compression step to improve the bonding formation. In still another aspect, the present invention relates to joining methods that use a passage for a material by which the joints are made. It should be understood that the modalities described in the specification are expressed in terms of preferred embodiments so that throughout this specification is not excessive. It should be understood that the present invention does not intend to be limited to such modalities. It should also be understood that aspects of the methods described herein may be combined in a single process, or may be used individually, or in any desired combination. Additionally it should be understood that the inventors consider that all such uses or combinations of these aspects potentially comprise patentable inventions separately, and that the scope of such inventions is intended to be as broad as the prior art allows. The scope of such inventions is intended to be limited solely by the claims, and not by the preferred embodiments described herein. Particularly in preferred embodiments, the methods of bonding materials described herein may also be used to provide the absorbent articles (or other types of articles), or portions thereof, with three unique dimensional shapes using the joining process to apply forces external to the portions of the articles to form them.
1. Description of a Non-limiting Modality of the Method of the Present Invention: For Use in Making a Tube of Absorbent Material for a Sanitary Towel
The method of the present invention can be used to join many different materials for use in many different types of articles, including absorbent articles. Figures 1-8 show a particularly preferred use of the method of the present invention. Figures 1-8 show a process for making a tube of the absorbent material to place it on the side that is in contact with the body of a base pad to form a composite sanitary napkin. A composite sanitary napkin comprises a primary menstrual pad (the tube of the absorbent material) that is attached to a panty-protector (the base pad). The tube of the absorbent material is bonded and formed by the method of the present invention. The final product is shown in Figure 13. The drawings show a number of steps that take place before (and after) the step of joining the materials comprising the tube of the absorbent material. It should be understood that the number of these steps are optional, and are shown because they are useful for making the absorbent product shown in Figure 13. All uses of the method of the present invention need not include these optional steps. It should be understood that the method of the present invention is not limited to the method shown in Figures 1-8, and that the method shown in Figures 1-8 is merely exemplary.
A. Assembling the components.
Figure 1 shows a composite network of material 20 to be bonded using the method of the present invention, and formed into an absorbent tube for use in the sanitary napkin shown in Figure 13. The composite network of material 20 shown in Figure 1 it comprises a first material, such as a first web of material 22 that is incompatible with the joint that is used in conventional techniques, such as adhesive, heat and / or pressure, and ultrasonic. The first web of material 22 can thus also be referred to as the "incompatible material of union" or "network of incompatible material." The network of incompatible material 22 has a first surface 22a and a second surface 22B.The first incompatible material 22 can be any suitable material Preferably, the network of incompatible material 22 is an absorbent material, although substantially non-absorbent incompatible materials can be joined using the method of the present invention.The network of incompatible material 22 can, but not necessarily, be compressible and Preferably, in this aspect of the invention, the first material 22 comprises a porous, compressible and elastic material The first material 22 is not limited to materials in the form of networks The first material 22 can be of any suitable form. example, the first material 22 may be in the form of a mass of particles or fibers, a sheet, one or more layers, strip s, leaves, blocks, or networks. Preferably, to make the tube of absorbent material shown in the drawings, it is in the form of a network. The network of incompatible material 22 has a first connection (looseness, or degree for which it is capable of joining other materials or having other materials attached thereto). The network of incompatible material 22 may, but need not, be completely incompatible with conventional joining techniques. For example, it can be a material to which other materials are not ready to join using such techniques. The bonding capacity of a material can be determined by measuring the force required to separate the material from a joint, or by trying to join it with another material. For the purpose of this definition, separation occurs under the forces in which the two materials can be debarked, or the force in which the integrity of the structure of the incompatible material is broken during the process of trying to separate the materials, The thing that happens first. The network of incompatible material 22 can be a material to which other materials are not ready to join for one or more reasons. More often, such materials are incompatible with conventional joining techniques because of their structural integrity or composition. One type of incompatible material is a porous polymeric absorbent foam material made from a high internal phase emulsion (or "HIPE" foam.) Absorbent foam materials having these characteristics are described in the patent literature, and include, but are not limited to, are limited to the following patents: US Pat. No. 5,260,345 issued on behalf of DesMarais, et al., on November 9, 1993; U.S. Patent 5,268,224 published in the name of DesMarais, et al. on December 7, 1993; and U.S. Patent 5,387,207 published on behalf of Dyer, et al. on February 7, 1995. Such materials may have a tensile strength and / or low structural integrity and / or a low level of elongation before breaking.
It is difficult to bond other materials to these absorbent foam materials using adhesives because the structural integrity of such materials is often not as strong as the adhesive bond. As a result, only portions of the incompatible material that are in direct contact with the adhesive will remain attached to other materials. The rest of the incompatible material will quickly be separated from the material to which it was attached. In addition, the foam materials described in the patents listed above can not be bonded to other materials using heat bonds because these foams are thermally hardening polymers. Once they are formed, they can not be recast. Instead, when heat is applied to these foam materials, they will carbonize instead of melting and flowing, which is necessary for heat bonding. These foam materials can not be press-bonded to other materials because the thermally hardening foam material does not have the ability to flow and be melted under pressure. The network of incompatible material 22 can, thus, also be referred to as a material that is not ready to join. In some cases, it can also be referred to as non-heat sealable, free of thermoplastic material, and / or as a material having a low structural integrity. It should be understood that the use of an incompatible material is only important in the aspect of the present invention which deals with a method of incompatible bonding materials. In another aspect of the method described herein, it is not necessary to use an incompatible material. In said other aspect, any suitable material, including a wide variety of absorbent materials, can be used. In the embodiment shown in the drawings, the network of incompatible material 22 is a network of absorbent foam material as one of those foam materials described in the aforementioned patents. The network of incompatible material 22 in the embodiment shown in Figure 1 is at least partially wrapped in a second web of material 24. The second web of material 24 has a second attachment capacity that is greater than the bonding capacity of the web. network of incompatible material 22. That is, it can be more readily joined to other materials (or to itself) using conventional joining techniques. The second material network 24 can also be referred to as a "carrier network" or a "unible network". In the embodiment shown in Figure 1, the second web of material 24 is preferably and completely wrapped around the network of incompatible material 22 such that the second web of material 24 has a folded "e" transverse configuration. The second web of material 24 can be of any material that is capable of being bonded to itself, or at least of some materials used in the types of absorbent articles described herein by heat or pressure, adhesives or ultrasonics. The second web of material 24 can be manufactured from a wide variety of materials such as woven and non-woven materials; polyhedral materials such as formed opening thermoplastic films, plastic opening or non-opening films, and hydroformed thermoplastic films; porous foams, cross-linked foams; crosslinked thermoplastic films; and thermoplastic screens. Suitable woven and nonwoven materials may be compressed from natural fibers (eg, wood or cotton fibers), synthetic fibers (eg, polymer fibers such as polyester, polypropylene or polyethylene fibers), bicomponent fibers (ie, fibers that have a core of a material that is encased in a sheath made of another material), or a combination of natural and synthetic fibers, preferably, in the embodiment shown, the second web of material 24 at least partially comprises thermoplastic material. other embodiments, however, particularly if adhesives or other types of bonds are used, the second material 24 need not comprise thermoplastic material, instead, the second material 24 may be a cellulosic material that can be attached to itself by a hydrogen bonding
In still another embodiment, the second web of material 24 can be replaced by a material having a form other than a web of material. For example, the second web of material 24 can be replaced by a bondable or covered layer such as an exudate glue cover or a polymeric cover that is applied to the network of incompatible material 22. The glues, particularly the hot melt adhesives, are similar to thermoplastic materials in that they are capable of being joined using this aspect of the method of the present invention. Certain silicones, particularly if they have sufficiently low melting points, will also be capable of being joined as described herein. For this reason, the second web of material 24 can be referred to as a second material in such a way that it is clear that materials other than networks are included. In the preferred embodiment shown in the drawings, the second material 24 preferably comprises material that is also suitable for use as a wrap for the absorbent material in an absorbent article. For example, the material 24 can serve as a container network for containing absorbent material in the absorbent article, such as a cover or top sheet for the absorbent article, or as a backsheet for the absorbent article. For the embodiment shown in Figures 1-8 and 13, the second material 24 comprises a container network made of spunbonded nonwoven material. A particularly preferred non-woven material joined by centrifuge is a 19 19 g / yd2 (22.5 g / m2) non-woven polypropylene material bonded by centrifuge referred to as product. No. 065MLPV60U (or "P-9") obtained by Fiberweb, North America from Washougal, WA. Another particularly preferred nonwoven material is a spin-linked polyethylene nonwoven known as COROLIND sold by Corovin GmbH, Peine, Germany, which can be obtained in two base weights, 23 gsm and 30 gsm.
Although the second web of material 24 is wrapped around the network of incompatible material 22 in a folded-e configuration, it should be understood that if a web of material is used, the second web of material 24 is not limited to wrapping the network of material. incompatible material 22 in a folded configuration- "e". The relationship between the incompatible material network 22 and the second material network 24 is preferably one in which a network of material having a higher binding capacity than the network of incompatible material 22 is merely at least adjacent to two opposing surfaces (eg, 22A and 22B shown in Figure 1) of the network of incompatible material 22. Thus, in other embodiments, the second web of material 24 can only be partially bent or wrapped around the network of incompatible material 22. The second web of material 24 can be folded or wrapped around the incompatible material 22 in any other appropriate embodiments. Other appropriate configurations include, but are not limited to, C-folded configurations, and the like. It is not necessary that the second web of material 24 be limited to a single network that wraps the network of incompatible material 22. One (or more) webs of material can be placed adjacent to each surface 22A and 22B of the network of incompatible material 22 For example, in other embodiments, there may be two separate networks of material 24, one of which is placed adjacent to each surface 22A and 22B of the network of incompatible material 22. The two networks of the second material 24 may be of the same type of material and have the same characteristics. In other embodiments, the two webs of material that are placed adjacent each surface 22A and 22B of the network of incompatible material 22 may differ. For example, there may be different types of materials, or they may be the same basic types of materials, but have different characteristics. In still other embodiments, the second material 24 need not be a network that is as wide or as long as the network of incompatible material 22. Instead, the second material 24 may be in the form of strips, bands, patches, or pieces located in a desired location for the junction points. Thus, the second material 24 only needs to cover a portion of the first and second surfaces 22A and 22B of the network of incompatible material 22.
B. Optional Intermediate Steps (1) Forming the Incompatible Material in Particle Material. In the preferred embodiment of the process of making the tube of absorbent material shown in Figures 1-8, before the joint and the shape take place, the network of incompatible material 22 will be formed into particle material as long as it is within the second network of material 24. This will be done by the process described in commonly assigned US Patent Application Serial No. 09 / 027,379 entitled "Method of Making Absorbent or Particulate Absorbent Materials" filed on behalf of Ronald R. McFAII, et al. on February 20, 1998. In such a case, it is preferable that the second network of material 24, not only be more unbreakable than the network of incompatible material 22, but also have a performance to break the point that the network of incompatible material 22. This operation (which forms the incompatible material in particle material) is an optional step that is preferably preformed prior to carrying out the bonding step, which is highly preferred for making the tube of absorbent material for the sanitary napkin shown in Figure 13. It should also be understood that the step of forming incompatible material into particle material is not limited to being performed before the joining step. The step of forming the incompatible material into particle material can alternatively be carried out at the same time as, or after, the joining step, if desired. The reasons for this optional step to be preferred are discussed in more detail below.
The optional process of forming the incompatible material 22 into particle material comprises several steps. Although there are several modalities of this optional process (and the apparatus used herein), a preferred embodiment of the process and apparatuses are shown in Figure 2. The process and apparatuses shown in Figure 2 are used to form the incompatible material 22 in particle material by mechanically stranding the incompatible material 22. A first step involves providing a "carrier network" having a first point of rupture strength under tension forces that is provided. (In the embodiment described herein, the second web of material 24 serves as a carrier network) The network of material to be formed into particle material (which in this case is the network of incompatible material, foam absorbent material 22) and the carrier network are then formed into a composite structure, such as a composite network 20. The foam absorbing material 22 has a second breaking point resistance under stresses that is lower than the breaking point resistance of the carrier network non-woven 24. Thus, the first two steps of forming the incompatible material 22 in particulate material have already been carried out in the preparation for the joining method described herein. An apparatus for mechanically straining the composite network 20 is provided. The apparatus preferably comprises a device having at least one component with a surface patterned thereon. The composite network 20 is then preferably subjected to a mechanical casting process using the apparatus by printing the patterned surface thereon into the composite network 20 such that the foam absorbent material 22 is at least partially formed of particle material without forming the carrier network (the second network of material) 24 in particle material.
The apparatus 30 for mechanically straining the composite network 20 shown in the Figure comprises two pairs of cylindrical rolls 32 and a second pair of rolls 62. Each of the rolls has a surface patterned thereon. The models are preferably formed by a plurality of ridges and valleys on the rolls that define a plurality of teeth triangularly formed. Modeled rolls suitable for use as the first and second pair of rolls 32 and 62 of the apparatus shown in Figure 2 (although not for this purpose of forming incompatible material in particle material) are described in greater detail in US Pat., 518,801 entitled "Network Materials Exhibiting a Type-Elastic Compartmentalization" published on behalf of Chappell, et al. on May 21, 1996. In the preferred embodiment shown, the rolls in the first roll pair 32 preferably have triangularly formed teeth that are formed by ridges and sills that are oriented around the circumference of the rolls. The teeth preferably have cross sections in the shape of isosceles triangles. The appendix of the teeth may be slightly rounded, if desired. The upper rolls 34 and the lower roll 36 in the first pair of rolls 32 are aligned in such a way that the ridges 38 of the upper roll 34 are aligned with the valleys 40 in the lower roll 36. The teeth formed in a triangular shape forming the hills in the upper roll 34 and the valleys in the lower roll are spaced such that these teeth do not touch each other or "mesh" completely. The teeth can be of any size and separation. The term "separation", as used herein, refers to the distance between the appendages of the adjacent teeth. In the preferred embodiment shown in the drawings, the depth (or height) of the teeth is preferably between 0.1 inches and about 0.17 inches (about 2.5 mm to about 4.3 millimeters). The spacing is preferably between 1 mm and about 5 mm, and more preferably between 1.5 mm and about 2.5 mm. The separation of the teeth establishes the width of the pieces in which the absorbent material is cut or pressed. The lower roll 36 may also comprise several thin spaced planar channels 44 on the surface of the lower roll 36 which are oriented parallel to the axis, X, of the lower roll. In this embodiment, the channels spaced apart 44 in the lower roll 36 preferably have a width of 2 mm. The "length" of the teeth in the lower roll 36 measured around the circumference of the lower roll between the spaced apart channels is 8 mm. The rolls 34 and 36 are preferably driven in opposite directions. The teeth triangularly formed in the upper rolls 34 and the valleys 40 in the lower roll 36 should preferably be spaced such that they are internally engaged. The degree to which the teeth in the opposite rolls are internally meshed is referred to herein as the "coupling" of the teeth. The coupling of the teeth is the distance between a position where the appendages of the teeth in the respective rolls are in the same plane (0% coupling) to a position designated by plane where the appendages of the teeth of a roll extended in the interior beyond the plane towards the valleys in the opposite roll. The coupling of the teeth can be expressed as a percentage of separation (distance between the appendages of the teeth in one of the rolls), or in terms of a measured distance. Since the length of the teeth can be greater than the separation, the coupling is greater than the height of the separation). Preferably, the coupling is between 15% and about 120% of the separation height. The coupling expressed in terms of a measured distance is preferably between about 0.01 inches and about 0.07 inches (about 0.25 mm to about 1.8 mm), and more preferably is between about 0.04 inches to about 0.06 inches (about 0.06 inches). 1 mm to about 1.5 mm).
As shown in Figure 2, in the step designated A, the composite network 20 is fed in a machine direction (MD) in the grip between the rolls 34 and 36. The second network of the material 24 in this stage of the process serves as a carrier network. As a carrier network it holds and contains the network of incompatible material 22 which is to be split and formed into particle material. The second web of material 24 wraps the outside of the network of incompatible material 22 such that the second web of material 24 contacts the patterned surfaces on the rolls 34 and 36. The rolls 34 and 36 hold the composite network 20 to a process of mechanical casting by printing the patterned surfaces on themselves in the composite network 20. The mechanical casting process applies a force that is higher than that of the breaking point strength of the network of incompatible foam absorbent material 22, but less than the breaking point resistance of the non-woven carrier network (the second web of material (having the greatest bonding capacity)) 24 such that the network of incompatible foam absorbent material 22 is at least partially creased without splitting the carrier network 24. Figure 2 shows the condition of the composite network in stage B, then passes through the grip between the first pair of rolls 32. As shown in Figure 2, the carrier network 24 will have a pattern of corrugations formed therein which corresponds to the combination of the models in the adjacent rolls, 34 and 36. The carrier network 24, however, is not split or cut. The intermediate web of absorbent foam material 22 has a plurality of slits 50 formed therein. The slits 50 are oriented in the machine direction (or "MD"). In the particular embodiment shown, the slits 50 are intermittent and separated by the cross machine direction (or "CD") strips of the non-slit material 52. This is due to the presence of the channels 44 in the bottom roll 36. network of the foam absorbent material 22 is slit while the carrier network 24 is not split because the net of foam absorbing material 22 has a breaking point strength less than the breaking point resistance of the carrier network 24, and breaks , under tension forces (the casting process) while the carrier network 24 does not. At this point in the process, (in step B, between the first and second set of rolls, 32 and 62) it is possible to perform additional operations on the composite network 20. For example, the composite network 20 can be cut into discrete lengths between the first and second sets of rolls 32 and 62. In other embodiments, the composite network 20 may be cut into discrete lengths by a cutting sheet located in one of the rolls in the first set of rolls 32. The composite network 20 would be cut into lengths corresponding to the length of the desired tube for the sanitary napkin in Figure 13. Additionally, an additional network (or nets) of material, such as a continuous network of open top sheet material 56, can be joined together. to the composite network 20 between the first and second sets of rolls. Alternatively, as an additional material it could be cut into individual pieces and attached to the composite network 20 between the first and second set of rolls. The one joining the open film upper sheet material 56 to the composite network 20 is shown in Figure 3. It has also been omitted from Figure 2 for simplicity of illustration. The open film upper sheet material 56 is preferably bonded to the composite network 20 by adhesives. This forms a structure which will be referred to herein as "compound forming tube" (or "composite netting tube") 88. The second set of rolls 62 of the apparatus 30 for mechanically casting the composite network comprises upper and lower rolls, 64 and 66, respectively. Each of these tubes also has a design on its surface. As shown in Figure 2, the upper rolls 64 have separation running parallel to the axis. X, of the upper roll. The separations define a plurality of triangularly formed teeth 68. The upper rolls 64 may also have several separate spaced channels 70 that are oriented around the circumference of the cylindrical roll. Figure 2 shows that when the composite net 20 leaves the grip between the second set of rolls 62, at least a portion of the foam absorbent material 22 is further provided with a plurality of slits 80 that are oriented in the cross machine direction . This initial split in the machine direction and subsequent slits in the cross machine direction results in the absorbent material 22 being formed or cut into a plurality of particles 82. The foam absorbent material 22 may optionally have non-slit strips 84 left in them due to in the presence of the channels 70 in the second pair of rolls 62, in addition to any cross machine direction bands of non-split material due to the presence of the channels 44 in the lower roll 36 in the first pair of rolls 32. A again, the non-woven carrier network 24 is not split, but has another model formed therein. The complete model formed therein resembles a grid with a combination of impressions created by the first and second sets of rolls 32 and 62. The upper sheet of open film 56 will have a pattern formed therein that resembles the second pair of rolls 62. Figure 3 shows the composite network 20 after it has been fed through the apparatus shown in Figure 2. As discussed above, a sheet of open film upper sheet material 56 has been preferably bonded to the individual lengths of the composite network 20 between the first and second pairs of rolls. Figure 3 shows that the sheet of open film upper sheet material 56 is preferably of a size that is more or less the same thickness as, but not longer, the individual lengths in which the composite net 30 was cut. The open film 56 extends beyond the ends of the individual lengths of the composite net material such that the tube of the absorbent material, once formed, can be more easily attached to the sanitary napkin, joining only the ends of the absorbent material. same to the sanitary towel. It should be understood that in Figure 3, the model printed on the non-woven material 24 by the first and second sets of rolls has been omitted for simplicity. In addition, the incompatible foam absorbent material 22 is shown as compressing only particles 82 for simplicity (ie, non-split strips are shown as left in the incompatible material 22). Such a mode could be created by providing the rolls in the first and second sets of rolls 62 with the continuous teeth omitting the valleys 40 and channels 70 between the teeth.
(2) Optional Tube Folding Step Forming the Composite Network
The next step for making the tube of the absorbent material for the sanitary napkin shown in Figure 13 is to fold the combination of the composite network 20 and the upper sheet material sheet open 56, the tube forming the composite net 88 These optional but preferable folding steps are shown in some of the following drawings. Figure 3 shows the longitudinally oriented folding lines, F, close to which the longitudinal side margins 90 of the tube forming the composite network 88 will initially be folded. Figure 4 shows the tube forming the composite net 88 before the lateral margins 90 thereof have been folded along the fold lines F in a first operation to form a folded structure "C".
Figure 5 shows the tube forming the composite network 88 before it has been folded in a second operation. As shown in Figure 5, the tube forming the composite network 88 has been folded along its longitudinal center line, L. As a result, the previously folded longitudinal side margins 90 are brought adjacent to each one. , and the longitudinal side margins 90 of the tube forming the composite net 88 are hidden within the folded tube forming the composite net 88. As shown in Figure 5, the folded longitudinal side margins 90 rest adjacent to the line longitudinal centers, L, of the tube forming the composite network 88. The folded tube forming the composite network 88 shown in Figure 5 is now ready to be joined using the method of the present invention. (The steps shown in Figures 2.5 are all optional, but preferred steps for making a tube of absorbent material for a sanitary napkins shown in Figure 13. O Union (and Formation) of Incompatible Material
(1) In General
To join (and form) the incompatible absorbent foam material 22, in the most general form, the web of material having a superior bonding capacity (the non-woven) 24 is placed on the outside of the incompatible material (the material of absorbent foam) 22. The cross section of the current structure that is attached (as shown in Figure 7) is somewhat more complicated than that, but for the purposes of the present description, the general relationship described above (with the network of material having the second highest unit capacity placed on the outside of the network of the incompatible material) is preferably present.
This incompatible material, the absorbent foam material 22, with the network of the material having the second highest unit capacity, the nonwoven web 24, on the outside thereof, is preferably bonded with a plurality of autogenous bonds. The term "autogenous", as used herein, refers to bonding without adhesives or other additional materials (ie, in addition to the components that will be attached) as a knit yarn. The method described herein, however, is not intended to be limited to methods that exclude the adhesive argumentation of such an autogenous bond, or adhesive bond per se. The joints 94 preferably penetrate the compatible absorbent foam material 22. The joints 94 preferably join one portion of the nonwoven web 24 to another portion of the nonwoven web 24 on the opposite side of the incompatible foam material 22. In the embodiment shown In the drawings, the joint serves as a step in the method of the present invention aimed at bonding incompatible materials, and also serves to provide the tube with absorbent material in a unique three-dimensional shape. By carrying out the method of the present invention, any appropriate number of joints 94 can be used. The joints 94 can also be placed in any appropriate place. To make the tube of absorbent material for the sanitary napkin in Figure 13, two to five joints 94 are preferably used, In the embodiments shown in the drawings, three joints 94 are used. The joints 94 are preferably spaced by about 1.75 inches (about 4.4 cm), and are located at about 17 mm of the fold made along the longitudinal center line, L, of the tube forming the composite network 88. The preferred autogenous bond can be completed using heat and / or pressure, or by ultrasonics. Appropriate techniques for bonding by heat and / or pressure, and dynamic bonding in particular, are described in more detail below. Appropriate techniques for joining ultrasonically are described in the North American Patent of Procter & amp;; Gamble 4,430,148 entitled "Ultrasonic Bonding Process" published on behalf of Schaefer on February 7, 1984 and US Patent 4,823,783 entitled "Free Bonding of Network Adhesives that Move Continuously to Form a Web of Sheet and Cut Out Products of the Same" published on behalf of Willhite, Jr. El al. on April 25, 1989. The appropriate equipment for ultrasonic joints is available from Branson Ultrasonics of Danbury, CT. The ultrasonic bonding apparatus is preferably equipped with a plate having the elements of models similar to those described below for the dynamic bonding process. It should be understood, however, that the ultrasonic junction may be less preferred (than the dynamic bonding process) for use in joining the higher caliber structures described herein. A dynamic bonding process has many other advantages over ultrasonic bonding processes. First, it can be a continuous process that is capable of operating at high speeds. In contrast, ultrasonics generally require the use of an apparatus having at least one static head that provides a fixed interval of time to form the joint. Thus, in the ultrasonic bonding processes, the network that will be joined has to be stopped for a period to complete the union. Second, ultrasonic bonding processes are not so suitable for bonding by materials having thickness over a certain amount (eg, above, or greater than or equal to, about 4 mm). The dynamic bonding process described herein, on the other hand, can easily be joined by materials having such thickness. The crevice or formation of the absorbent material 22 in particulate material in the previous step is advantageous in the joining process. This is because the method used to form the slit or particle material can provide a continuous clear path for the joints to penetrate through the absorbent material. This is particularly in the case where the joints are aligned with the slits or spaces between the particles. This occurs more frequently when the slit or particle material is adhered to a conveyor network. The above methods of the suppressive absorbent material which merely suppress the absorbent material and blow them by compressed air in a closed tube will result in a random distribution of the suppressed particles. Such methods will not form the clear path of the joining process described herein. The dynamic bonding process, as discussed above, involves portions of the second web of material (non-woven cover) 24 on each side of the absorbent foam material 22. The open film upper sheet material 56 may also have portions that are dynamically linked The open film upper sheet material 56 can be further bonded to, or alternatively to, nonwoven cover binding portions 24. In the dynamic bonding process, at least one of the materials to be joined (the non-woven cover 24) or the open top sheet material 56) preferably comprises thermoplastic material. (It should be understood that, for simplicity, the joint will be expressed in terms of the joining portions of the non-woven cover 24, although portions of the open top sheet material may be similarly joined in the process). Figure 8 shows the process in which a first portion 24a of cover material 24 is preferably joined through the tube forming the composite net 88 to a second portion 24B of the cover material. The apparatus used to join the tube forming the composite net 88 preferably comprises a pair of cylindrical rolls 110 and 112. Preferably, at least one of the rolls, the patterned roll 110, has a pattern in relief on its surface. The patterned roll 110 is shown in a simplified manner in Figure 8 in greater detail in Figure 12. (Figure 12, however, shows a roll with an embossed pattern thereof that is also different from the model shown in FIG. Figure 8).
As shown in Figure 12, the patterned roll 110 has a cylindrical surface 115, and a plurality of protuberances or pattern elements (or "model element segments," "projections," or "pieces") 116 that they extend externally from the surface 115. The raised pattern formed by the pattern elements 116 may be of any suitable configuration. They can be linear, curvilinear, or they can be comprised of linear segments and curvilinear segments. The relief model can be continuous or intermittent. The relief model can define an unlimited number of models and other types of designs. For example, you can define geometric shapes, arrows, words, etc. The landing surfaces 118 on the model elements can also be provided in a wide variety of possible ways. Suitable shapes for landing surfaces 118 include, but are not limited to, oval or circular. In the embodiment of the apparatus shown, the relief model comprises a plurality of spaced-apart model elements 116 having circular landing surfaces 118. In the embodiment of the method shown in Figure 8, the model elements are harangued in a linear configuration intermittent. While the present invention seeks to apply the joints in any appropriate shape and size, the sizes of the joints that have been found to be suitable have a circular plane view configuration with a diameter of between about 0.25 mm to about 5 mm or plus. In a preferred embodiment, the joints have a diameter of about 3 mm and an area of about 8 mm2. The pattern elements 116 have side walls 119 that are preferably not perpendicular to the surface of the cylindrical roll. Preferably, the side walls 119 of the pattern elements 116 form an angle of more than 45 ° and less than 90 °, preferably between about 170-90 degrees, with the surface 115 of the cylindrical roll. Modifying the orientation of the side walls 119 of the pattern elements 116 is preferred due to the thickness of the materials to be joined, and the desire to avoid spilling the cover material 24. The other roll 112, serves as an anvil member. and, thus, can be referred to as an anvil roll 112. The patterned roll 110 and the anvil roll 112 define a pressure predisposed grip 114 in the middle. Preferably, the anvil roll 112 is a smooth surface. In other embodiments, however, both rolls 110 and 112 may have a raised pattern and / or pattern elements therein. The patterned roll 110 and the anvil roll 112 are preferably biased towards each other with a predetermined pattern element of about 20,000 psi (about 140 MPa) to about 200,000 PSI (about 1,400 MPa). In the embodiment shown in Figure 8, the rolls are predisposed towards each other in such a way that the pressure in the grip 114 is preferably maintained at about 93700 psi (about 656 MPa.). In this embodiment, the materials to be bonded are preferably fed by grip 114 in a relatively high speed range. The speed of the line is preferably about 383 feet / minute (about 117 m / minute). The patterned roll 110 and the anvil roll 112 are preferably driven in the same direction at different speeds such that there is a differential surface speed between them. The differential surface velocity preferably has a magnitude of about 2 to about 40 percent of the roll having a lower surface velocity, more preferably between about 2 to about 20 percent. The anvil roll 112 is preferably operated at a surface speed that is greater than the surface speed of the patterned roll 110. It is also possible, however, at high line speeds, for the joint to occur at a differential speed of zero (that is, with the rolls that define the grip equal to the surface velocities).
The plural sheet comprising the tube forming the composite net 88 is joined by feed in the grip 114 between the rolls 110 and 112. The preferred joining process shown in the drawings penetrates through the tube forming the composite network 88 and autogenously joins the first portion 24A of the nonwoven cover material to the second portion 24B of the cover material 24. The joints 94 are formed between the opposite portions of the non-woven network of the material 24 having the second largest unit capacity that is placed outside the foam material 22. Without wishing to be bound by any particular theory, the mechanism by which the union of the incompatible material is believed to occur is as follows. The pattern elements 116 of the joining mechanisms compress the incompatible absorbent foam material 22. This localized compression causes the incompatible absorbent foam material 22 to fracture and separate (move away from the pressure point) from the area of the pattern elements 116. The joining mechanism cuts through the incompatible material 22 or displaces the particles of the incompatible material 22 such that there is a free path for the joining materials. Preferably, very little (if any) of the foam material 22 is currently left in the bonding sites. In addition to the penetration of the incompatible material by the joints, the method described herein has several other important characteristics. These characteristics allow high caliber materials to be joined, and allows the process to create a virtually unlimited number of bonding models in the materials that will be joined. The patterned roll 110 preferably has a deformable (or compressible) material 120 on its surface 115. The patterned roll 110 preferably also has a pair of load bearing members 122 on its surface 115. The purposes of these components are described below.
The object of the deformable material 120 is to compress the materials to be joined in such a way that the pattern elements 116 have less possibility of perforating the cover material (s) 24. If the cover material (s) is perforated, to the joints either they will not form, or a weak bond will be formed because the cover material will not be fused to form the joint. The compression step can occur before, or simultaneously with, the joint. The use of a deformable material is particularly preferred when the materials to be bonded are relatively thin. The deformable material can be omitted when the materials that will be joined are thinner.
Figure 12 shows that the deformable material 120 preferably surrounds the model elements. ! Compared to Figures 9 and 10 it shows how the deformable material 120 is believed to work. Figure 9 shows a relatively thin material passing through the grip 114 between the modeled roll 110 and the anvil roll
112 without a deformable material surrounding the pattern element 116. As shown in Figure 9, the pattern element 116 tends to perforate the materials that will be joined due to the high stress located in the materials to be bonded, particularly the cover material 24. Figure 10 shows the same relatively thin material passing through the grip 114 between the patterned roll 110 and the anvil roll 112 with a deformable material 120 surrounding the pattern element 116. As shown in the
Figure 10, the deformable material 120 occupies the space between the patterned roll 110 and the anvil roll 112. The deformable material 120 causes the material to be bonded to be gradually compressed in the area of the design element 116. This brings both of the layers of the cover material 24 closer during joining without applying an added stress to the cover material 24, or to punch a hole through which the foam material 22 located between the layers of cover material 24.
The way this works can be visualized with the following analogy in mind. The principle involved is similar to the problem of trying to secure a thin piece of six inches (15 cm) of fiberglass cover insulation to another material using a nail gun. If this is attempted when the fiberglass is not yet compressed, when the nail is exerted, it will puncture the insulation and pass completely through the insulation. However, if the fiberglass insulation is compressed before an attempt is made to secure it with a nail gun, this will not happen, and the nail is able to insure the insulation. The deformable material 120 preferably has certain characteristics. The deformable material 120 is preferably less compressible than the materials to be bonded, and more compressible than the surface 115 of the patterned roll. Therefore, the deformable material 120 will preferably have a hardness less than that of the surface 115 of the patterned roll 110. Preferably, the deformable material 120 has a hardness (which is measured using a durometer) of about 50 on the scale from Shore A to about 62 on the Rockwell C scale, more preferably it has a hardness of about 90 on the Shore A scale. (A hardness of 62 on the Rockwell scale is the hardness of the D2 steel that comprises the surface 115 of the patterned roll 110) (As long as the surface of the anvil roll can have any appropriate hardness, the surface of the anvil roll 112 preferably has a hardness that is equal to greater than that of the patterned roll.) The deformable material 120 can understand any type of appropriate material. Suitable materials include brass, rubber, and polymeric materials such as polyurethane. In a particularly preferred embodiment, the deformable material 120 comprises polyurethane. The deformable material 120 is preferably wider in width than the materials that will be bonded. This allows you to equalize the pressure on all the materials that will be joined. The deformable material 120 can have any suitable gauge. Preferably, the caliper of the deformable material 120 is large enough to have some appreciable effects to avoid the problem of puncturing the holes through the cover material. The caliper of the deformable material 120 is preferably not greater than the height of the pattern elements 116. The model elements can, for example, have a height of about 2 mm. In a non-limiting embodiment, it has been found that the deformable polyurethane material having a hardness of about 90A on the Shore A scale having a height of about 1.5 mm which is appropriate. The deformable material 120 is preferably adhered to the surface 115 of the patterned roll. The deformable material 120 can be adhered to the patterned roll 110 in any suitable manner, such as by welding it, or by adhesives. The object of the load bearing members 122 is to balance the patterned roll 110 (ie, equalize the forces in the patterned roll 110 when the materials to be bonded pass between the patterned roll 110 and the anvil roll 112). The use of the face bearing members 122 is particularly preferred when the model in the patterned roll 110"is unbalanced" or "unbalanced", this means that the pattern elements 116 are distributed in a manner in which the pressure in the grip 114 between the patterned roll 110 and the anvil roll 112 varies around the circumference of the patterned roll 110 due to differences in the surface area of the terrains 118 of the pattern elements 116 and / or due to the distribution of the pattern elements 116. The load bearing members 122 can be omitted when the joint pattern is balanced. However, as will be discussed below in greater detail, the use of the load bearing members 122 may be desired even when the joint pattern is balanced to provide more flexibility in using elements of models 116 having greater height. The load bearing members 122 may be of any suitable configuration. The load bearing members 122 may be in the form of continuous rings around the patterned roll 110. It is possible for the load bearing members 122 to have the form of intermittent elements, however, they are preferably in an array that is staggered around the circumference of the patterned roll 110 such that they effectively form a continuous ring around the circumference of the patterned roll 110. As shown in Figure 12, the load bearing members 122 are preferably in the form of continuous rings around the patterned roll 110. In the embodiment shown in the drawings, the load bearing members 122 are preferentially located adjacent each side end of the patterned roll 110. load bearing members are preferably located laterally outside the surface portion 115 of the patterned roll 110 along which the materials to be bonded will contact (ie, they are preferably located between the central portion of the patterned roll 110 and the edges). laterals of the patterned roll 110). This ensures that the anvil roll 112 will be able to make direct contact with the load bearing members 122. It is believed that this contact will occur even when the materials to be bonded are fed into the grip 114 between the rolls. This contact is believed to occur due to the compression of the materials that will be attached in the grip 114 and the deformation of the rolls under high forces that will be applied to the inclination of the rolls toward each one. A comparison of Figures 11 and 12 shows in greater detail the manner in which the bearing load members 122 are believed to function. Figure 11 shows an example of a patterned roll 1110 having no bearing members of the type described in FIG. the present. The distribution of the pattern elements 1116 in the modeled roll 1110 is both "nested" and balanced. The term "embedded" as used herein refers to the distribution of model elements 1116 that exhibit a degree of overlap as a look at the model procedure around the circumference of the modeled roll 1110. This ensures that the anvil roll 1112 will be continuously anchored on the upper portions of the pattern elements 1116 in the grip area 1114, and will not leave or tilt between each model element 1116. If the pattern elements 1116 are not engaged, and the anvil roll 1112 will tilt between the 1116 model elements, the rolls, which have been held close at very high pressures and are rotating at high speeds, would operate in an extremely agitated manner, as in the case of a flat tire in a car. In the roll 1110 shown in Figure 11, there are identical groups of pattern elements similar to the group shown in other parts of the roll. There are also supports or support strips 1124 between the groups of model elements. The other identical groups of model elements can not be seen in Figure 11 because only a portion of the surface of the roll is shown. However, the only group of model elements and supports 1124 are sufficiently shown to describe the concept of the subject. As shown in Figure 11, when the model is balanced, any support or support strips 1124 need only be provided in a non-continuous (or intermittent) array around the circumference of the patterned roll 1110. The supports 1124 are provided in those places where the pattern elements 1116 are not present. This is because the total force of the loading mechanisms is transferred from the pattern elements to the supports 1124 when the modeled roll 1110 rotates. Balanced models are required meaning that the bonding areas in the grip (that is, the surface area of the portions of the rolls that are in contact in the grip) at any point around the roll should remain constant. If allowed to vary, the joint pressure would also vary and inconsistent joints would result. Figure 12 shows an example of a patterned roll 110 that can be used in embodiments of the method described herein that has a non-fitted and unbalanced model of the pattern elements 116 therein. Although only a portion of the roll 110 with a single group of pattern elements 116 is shown in Figure 12, the modeled roll 110 preferably comprises several similar models of spaced points around the circumference of the roll 110. (By "points", it is understood that the model elements have circular landing areas). Each group of points is distributed in the desired coupling to form unions in the product of the matter. For example, to join the tube forming the composite network shown in Figure 8, each group of points can be arranged in a three-point linear model. To join the interlabial device 1020 shown in Figure 15, each group of points can be in a semicircular arrangement of four or five points as in the case of the group of model elements shown in Figure 16. For the purpose of this discussion, it will be assumed that there are six groups of points around the circumference of the roll 110, all the elements of models 116 in this example are of the same height. Three of the knit patterns have pattern elements 116 with terrains defining a circular bonding surface having a diameter of 2 mm. The other three point models have model elements 116 with a circular joint surface having a diameter of 3mm. The groups of pattern elements 116 alternate around the patterned roll 110 with each of the 3mm diameter groups of the model elements following the 2mm group. of diameter of the model elements.
There is no convenient way known for the inventors to form joints using both elements of 2 mm models. in diameter and 3mm models. in diameter, prior to the invention of the bearing members 122 described herein. For example, using a conventional roll arrangement, it is possible to form joints with the 2mm elements. in diameter, but not with the elements of 3 mm. diameter. If the proper pressure was selected to form joints with the 2mm elements. in diameter, there would not be enough pressure to form joints using the 3mm elements. diameter. The opposite would also be true (it was possible to form joints with the 3mm diameter elements, but not with the 2mm diameter elements). If the proper pressure was selected to form joints with the 3mm elements. In diameter, the pressure would be too high to pair with the 2mm elements. in diameter and the holes would be punched through the materials that would be joined. The bearing members 122 described herein would then be disclosed. As described above, the bearing members 122 are preferably provided in the form of continuous rings around the circumference of the patterned roll 110. To ensure the dynamic balance of the patterned roll 110, a quantity of material equal to the surface area of the Model element is removed from the bearing members. As shown in Figure 12, the bearing members 122 preferably have small cutting areas 126 on each side. The cutting areas 126 are preferably located along the same longitudinal axis on the surface of the roll in which the pattern elements 116 are located. There are two cutting areas 126 for each model element 116. The cutting areas 126 shown in Figure 12 are each semicircular in shape. The size of each cutting area 126 is preferably equal to one-half the size of the surface of the pattern elements 116 that are located on the longitudinal common axis.
The bearing members 122 should have a hardness greater than or equal to the surface of the patterned roll 110 and the pattern elements 116. The bearing members 122 may comprise any suitable type of material. The bearing members 122, such as the surface of the patterned roll 110 and the pattern elements 116 are preferably steel tablets D2. The bearing members 122 can have a caliper that is smaller, greater or equal to the height of the pattern elements 116. Preferably, to simplify the process, the caliper of the bearing members 122 is the same at the height of the elements. of models 116. The elements of models 116 can, for example, have a height of about 2mm. In a non-limiting embodiment, it has been found that the bearing members 122 have a height of about 2mm. they are appropriate The bearing members 122 may have any suitable width. The bearing members 122 are preferably of a width that provides them with a surface area along each portion of a longitudinally oriented region, taken along the surface of the patterned roll 110 (ie, parallel to the axis of the pattern roll 110). roll) that is equal to or greater than the total surface area of the land 118 in the model elements 116 that rest in the same area. In the embodiment shown in Figure 12 the bearing members 122 have a width of about 6mm. (as measured by a portion of bearing members 122 that does not include cutting areas 126). The bearing members 122 may be integrally formed in the patterned roll 110, or may comprise separate elements that are adhered to the surface 115 of the patterned roll 110. The bearing members 122 are preferably integrally formed on the surface 115 of the patterned roll 110. If the bearing members 122 are adhered to the patterned roll 110, they can be adhered in any appropriate manner such as by welding.
Without wishing to be bound by any particular theory, it is believed that the bearing members 122 allow for the use of unbalanced models joints because the pressure in the joint area is no longer solely a function of the surface area of the model elements or a function of the presence or absence of model elements. With the bearing members 122, the pressure in the joint area becomes controlled by the material properties of the rolls, particularly the patterned roll 110, and the materials to be joined, as well as the geometry (i.e. surface area), of the pattern elements 116 and the bearing members 122. It is believed that since the joints take place under relatively high pressures used, there is a deformation of the rolls, particularly of the pattern elements 116. the bonding area is believed to result in a compressive deflection in the pattern elements 116. The pressure in the bonding area may also result in a degree of deflection to the surface of the patterned roll 110 around the base of the pattern elements. . The localized deformation in the anvil roll 112 in the place of the points of contact with the pattern elements 116 is also possible. It is believed that the magnitude of the deformations in the pattern elements 116 and the surrounding areas to form the thickness of the joints formed by this process. In the preferred embodiment described herein, the joints have a thickness in the range of about 0.0015 to about 0.002 inches (about 0.038 mm to about 0.05 mm.) This deformation allows the anvil roll 112 to remain in constant contact with the bearing members 122, even in the areas where there are model elements 116 present and the intervening materials to be joined have been fed into the grip 114 between the patterned roll 110 and the anvil roll 112. For this to be possible, the loading force must be high enough to ensure constant contact between the bearing members 122 and the anvil roll 112. The bearing members 122 thus act as a "stop" for the anvil roll 112 to prevent additional compressive deflections of the pattern elements 116. The bearing members 122 may be designed to be strong enough so that when the anvil roll 112 is in contact with the If the load force increases, only the load acting on the bearing members 122 would be increased, assuming that they were very high, it would be possible that additionally there would be no increase in the joint pressure on the pattern elements 116. rigid. The balance of the patterned rolls 110 has particularly important implications. This aspect of the joining method can be used to produce bonding models with model elements that have different land sizes around the circumference of the modeled roll. This aspect of the joining method can be used so that they are not subject to the above mechanical limitations. The union models do not have to have elements of embedded models, and the union models do not have to be balanced. For example, in the above joining processes, the creation of complex models, such as the type of model shown in Figure 17, which is embedded and balanced, involves an extremely complicated designation process. The balance of the modeled roll eliminates the need to go through a complex design job to ensure that the joint model is fitted and balanced. In addition, union models can be created and adjusted to meet particular union needs, or to meet consumer preferences, rather than the limitations of the process. In addition, the method described herein can be used to create an unlimited number of joint designs for aesthetic purposes or for other purposes. For example, using the techniques described herein can be used to write a manuscript or highlight a picture on the materials that will be attached. Additionally, the use of the bearing members 122 in the method allows the pattern elements 116 to have higher heights to be used. The elements of previous models were typically about 0.015 inches (about 0.38mm) in height. As discussed herein, the pattern elements 116 may be in a range of height greater than 2mm, or more. This allows thinner materials to be joined. Providing a roll modeled with elements of models that have a higher height, however, is not limited to be used in thin bonding materials. It can also be used to join by thin materials because the bearing members 122 will prevent the pattern elements 116 from piercing the materials that will be bonded. This aspect of the method is also believed to result by increasing the life of the modeled rolls 110. Generally, embossed rolls are no longer used for stress in the model elements. The use of bearing members is believed to reduce stress by cushioning a portion of this stress and reducing the pressure on the model elements. As discussed above, the bearing members may also act as a "stop" to prevent additional compressive deflections of the model elements. It is believed that because the bearing members can act as a "stop" to prevent additional compressive deflections of the model elements, the model elements will not be deformed beyond the plastic deformation points.
(2) Non-limiting variations of the joining process i There are many possible variations of the joining process described herein. A non-limiting number of these variations are below. For example, the methods described herein are not limited to being used in bonding materials for the use of absorbent articles. The methods described herein, for example, can be used to join materials for use in making packages, or other types of articles, particularly when incompatible materials, polymeric materials, or the like are used. In addition, the center plates of the materials that will be joined do not have to comprise an incompatible material. They can comprise any type of material, including but not limited to a thermoplastic material. In addition, the joining method described herein is not limited to the arrangement of the rolls shown in the drawings. In other modalities, for example, both rolls can be provided with model elements. In embodiments where both rolls are provided with model elements, the model elements can be arranged to make contact with each other. Alternatively, the model elements in one of the rolls can be arranged to make contact with the surface of the roll placed in locations between the model elements on the surface
The preferred method of joining together these materials can additionally comprise the step of heating one or both rolls, 110 and 112. If the rolls are heated, they are preferably heated to a surface temperature which is a predetermined number of degrees below the temperature of fusion of the thermoplastic material in the cover material 24. In other embodiments, the materials to be bonded may be compressed (or "precompressed") before they are fed into the grip 114 for bonding. For example, the materials that will be joined can be fed by a pressurizing grip between another pair of rolls before the set of rolls 110 and 112 precompress the materials to be joined. The precompression may involve the complete compression of the materials to be joined, or may comprise a compression located in those areas of the tube forming the composite network 88 in which the joints 94 will be formed. The pre-compressing step can also occur in conjunction with joining in other types of joining processes. For example, if they are used ultrasonically, the ultrasonic welder or "grafter" will generally cause the material to be bonded to decrease a degree of compression of the interval time needed to form the ultrasonic joint. Thus, in the case of an ultrasonic welding, a pre-complying step that separates it from the generally used joining process will not be required. Furthermore, for simplicity and clarity of the invention, the apparatus used in the joining process is described herein. as compression cylinders 110 and 112. However, the cylinders are members that define the grip but in an exemplary manner. Accordingly, it is not intended thereby to limit the present invention to an apparatus comprising cylinders per se. With this same feature, the use of the term "model element" is not intended to limit the method described to consistent joint designs of only model elements spaced to the exclusion of other models: example, reticulated models or models comprising continuous lines or of elongation of union. The methods described herein may further comprise any of the limitations of the process or steps described in U.S. Patent 4,854,984 issued in the name of Ball, et al. On August 8, 1989. Another factor that has to be taken into consideration when forming The unions using a dynamic union process are equally distributing the load on the elements of the model. This is more significant when a single joint roll or surface is used to join a material having portions with different thicknesses. Different thicknesses can occur in many different situations. For example, the material that will be joined could be profiled or processed in such a way that it has regions with different thicknesses. Alternatively, the material to be joined may comprise a sheet wherein the height and / or width of all the layers are not the same. In such a case, some of the joints may have to pass through more layers than the other joints. One way to equally distribute the load on the model elements in such situations is to vary the angle of the side walls 119 of the pattern elements 116. The angle of the side walls 119 of the model elements 116 that will be penetrating the portions of the material or materials to be bonded that have a greater thickness will be larger than those of the patent elements 116 that will be penetrating the portions of the material (s) having a smaller thickness. For example, the angle of the side walls 119 of the pattern elements 116 that will be penetrating the thinner portions of the material (s) to be joined can form an angle of about 50 °, and the angle of the side walls 119 of the pattern elements 116 that will be penetrating the thinner portions of the material (s) that will be joined can be about 70 °. The pattern elements 116 that will be penetrating the thinner portions of the material (s) to be joined may also have a higher height, if desired (or the other model elements may be made shorter). As discussed above, the method of the present invention can be carried out using adhesive, cohesive, hydrogen bonds (for example, if one of the materials to be bound comprises cellulose), heat and / or pressure, or ultrasonic . Such processes are particularly preferred if the unusable material, such as the second web of material 24, is treated by a chemical or composition that interferes with the usual bonding methods (particularly adhesives). For example, these joining processes would be preferred if the second material is treated with a skin care composition, or a material that alters the hydrophilicity of the second material. Examples of the subsequent types of surface treatments are described in the North American Patent of P &; G 5,693,037 entitled "Absorbent Articles Having Surface Hydrophilic Top Sheets", published under the name Yan-Per Lee, et al. on December 2, 1997. The dynamic bonding process and ultrasonic bonding processes described herein are capable of both bonding by such treatments and transferring sufficient heat through such covers or surface treatments that the bond may be formed with the material implicit. Alternatively, if such surface treatments are applied intermittently, the pattern in the joining device may be designed such that the joints penetrate the untreated portions of the material. Figure 7 shows the binding pads, or more preferably, displaces the compressible foam absorbent material 22 in localized areas where the joints 94 are formed. This seizes a dimensionally formed portion in three 100 of the tube forming the composite network 88 from the remainder of the tube forming the composite network 88) in a different form. The tube forming the composite net 33 is formed, preferably symmetrically, on both sides. This is possible because the joint exerts pressure on only a portion of the tube forming the composite network 88 where the tube forming the composite net 88 is compressed by the pattern elements 116 against the curved surface of the anvil roll. This embodiment of the method of the present invention, thus, differs from the processes of forming an ornamental figure in relief on a surface that could create a structure with a low relief side and a flat side.
D. Union of the Tube of Absorbent Material to a Base Pad to Form a Composed Sanitary Towel.
After the joining process the bonded tube forming the composite net 88 is preferably cut into a plurality of individual tubes of absorbent material, each of which will be placed on the surface of a base pad to form a composite sanitary napkin. As shown in Figure 8 the apparatus used to shorten the joined tube forming the composite network 88 comprises a pair of rolls 130 and 132. One of the rolls, the roll 130, has at least, and preferably a plurality of blade elements 134 on its surface. The blade elements 134 are preferably configured to make a continuous, generally transverse, cutting cut in the continuous joined tube forming the composite net 88. The other roll 130 and the anvil roll 132 also define a grip 136 in the middle. After the cutting step, the individual tube of the absorbent material 88 is sent to a conveyor 140 to attach it to the base pad to form a composite sanitary napkin. In the case of the individual tube of absorbent material shown in Figure 7, the remainder of the tube forming the composite network 88, which is not held together by joints, is unfolded and dispersed before joining the tube forming the composite network 88 to the base pad. The joining and deployment of the remainder 102 of the tube forming the composite network 88 forms the tube forming the composite network 88 in a profiled form in the portion of the tube forming the composite network 88 that will form the upper part of the absorbent tube in the finished product, a narrower width is given. Preferably, as shown in Figure 13, the portion of the composite net 88 that will form the upper part of the absorbent tube in the finished product defines a ridge 106 that perpendicularly protects from the top of the remainder of the composite tube 102 (and the rest of the sanitary towel). As shown in Figure 13, the joint also provides the tube forming the composite network 88 of a quilt-type model where the tube forming the composite network 88 is creased around the bonding sites 94. Figure 13 shows a sanitary towel 800 having the tube of absorbent material 88 on the side that is in contact with the body thereof, which was joined by the method of the present invention. To form the composite sanitary napkin 800, a sanitary napkin can serve as a panty-protector (or "base pad" 820 and the tube of absorbent material 88, which will serve as the "primary menstrual pad is placed on top of the base pad 820 and attached thereto at least at its ends.The sanitary napkin suitable for use as the base pad 820 includes the sanitary towel ALWAYS ULTRA sold by The Procter &Gamble Company of Cincinnati, Ohio. Particularly preferred embodiment, the base pad 820 comprises a variation of such sanitary towel ALWAYS ULTRA having an absorbent core comprising a woven sheet with particle of hydrogel material very absorbent in the medium and a fabric and an open film DRI- WEAVE superimposed on the absorbent core Suitable fabrics are manufactured by Merfin Hygienic Products The fabric overlaying the absorbent core is preferred attached to the absorbent core by a spiral pattern of adhesive. The tube of the absorbent material 88 may be attached to the base pad 820 in any suitable manner. The connection of the tube 88 to the sanitary napkin 820 is presently reached by the fusion-bonding extensions 58 of the upper sheet material 56 at the ends of the base-pillow tube 820. In some preferred embodiments of such a sanitary composite pad, they can be attached to the base pad 820 between the ends by any appropriate joining means, as by adhesives. The sanitary napkin 800 has a first end (or front) region 828, a second end region 830, and a central region 832 positioned between the first and second end regions. As shown in region 828 of sanitary napkin 800 to rear end region 830 of sanitary napkin as a result of bonding. More specifically, the tube of absorbent material 88 has its largest gauge at the center of the sanitary napkin along the transverse center line, T, and decreases to a smaller gauge at the ends of the sanitary napkin. The joining patterns can be varied to create a tube of absorbent material with gauge increased along or any portion of the length of sanitary napkin 800. For example, the joint can be such that the increased gauge is confined to the central region 832 of sanitary napkin 800. Alternatively, the binding pattern can be used to provide an increased gauge in the end regions, or in a portion of the central region and a portion of the end regions.
2. Alternative Modalities of the Method of the Present Invention Numerous alternatives of the present invention exist. For example, in an alternative embodiment, the absorbent material in the tube of the absorbent material need not be formed in particle material before it is joined. That is, a solid piece of absorbent material can be used. However, bonding by a solid absorbent material, such as an absorbent foam material, may be more difficult, particularly if it is more than about 4 mm thick. It is also possible to join by other types of materials, such as low density absorbent materials, using the method of the present invention. For example, the method of the present invention can be used to join by the non-calendered air filter. If it is desired that the air filter, the air filter can be calendered before it is wrapped in the bondable and bonded material according to the method of the present invention. The method of the present invention, however, provides several advantages compared to merely shaping an absorbent article, such as an absorbent article comprising an absorbent core of the air filter in bas-relief. In such absorbent articles, the topsheet may be adhesively bonded to the absorbent core of the air filter. The backsheet may also be adhesively bonded to the absorbent core of the air filter. The cellulosic fibers in the air filter are held together by hydrogen bonds. These hydrogen bonds suffer from the disadvantage that they tend to be released by liquids. The adhesives also suffer from the disadvantages they may have of being released by liquids and if certain surface treatments are applied to the components of the absorbent articles, such as the top sheets. Figure 14 shows another use of the method of the present invention. In the above embodiments, the method of the present invention involved laying materials that were capable of being bonded to the outer surfaces of an incompatible material and bonding these materials by penetrating the incompatible material. In Figure 14, the method of the present invention is used to join two incompatible materials to materials that are capable of being bonded, which rest within the incompatible materials. Figure 14 shows two networks of incompatible material 22. Networks of incompatible material 22 may comprise any of the incompatible materials described herein. Preferably, the networks of the incompatible material comprise an absorbent foam material. Although it is difficult to attach such absorbent foam materials to other materials using adhesives, in this embodiment, an adhesive layer 98 is used to bond each of the networks of the absorbent foam material 22 to a network of material 24 having a capacity of of superior union. This adhesive bond is, however, subject to the risks that the absorbent foam material can detach from itself due to the low structural integrity of the absorbent foam material. The webs of material 24 having a greater bonding capacity can be of any of the second materials described herein. Preferably, the webs of material 24 having the greatest bonding capacity comprise non-woven webs. As shown in Figure 14, the nets of the absorbent foam material 22, with the non-woven nets 24 adhesively bonded thereto, are placed in a face-to-face relationship with the non-woven nets 24 adjacent one to the other. The entire composite structure thus formed is then joined by the method described herein. The composite structure can be joined by passing it through a grip between a pair of rolls such as those in the apparatus shown in Figure 8. This will cause a joint 94 to be formed between the non-woven webs 24.
The jo94 in this embodiment can be a "hidden" jothat is not visible from outside the absorbent foam material 22. The jo94 can be hidden because this pattern element that formed the jowill typically displace a small amount of the material from foam. In addition, before bonding, the foam material 22 can expand over the bonding area to make the places where the foam material was displaced, less visible. In addition, the method described herein may be used for other purposes and to make other types of absorbent articles. Figure 15 shows an absorbent rlabial device 1020 that is joined and formed by the method of the present invention. The absorbent rlabial device 1020 may comprise any suitable absorbent material, including any of the compatible materials described herein. In the embodiment shown in Figure 15 the absorbent rlabial device 1020 comprises a rayon core 1044 which is wrapped with a nonwoven web cover material 1046. Rayon is typically incompatible if conventional joining techniques are used. As shown in Figure 16, however, the method of the present invention can be used to join and form the rayon core 1044 by providing links 94 between the nonwoven cover 1046 on opposite sides of the absorbent rlabial device penetrating the rayon. As shown in Figure 16, a first portion 1046A of the cover material 1046 is preferably bonded through an absorbent rayon material 1044 to a second portion 1046 of the cover material. The apparatus used to join the covered absorbent material 1044 preferably comprises a pair of cylindrical rolls, patterned roll and anvil roll, 110 and 112. The cylindrical rolls 110 and 112 are similar to those shown in Figure 8. As in the embodiment shown in Figure 8, preferably, at least one of the rolls, the roll 110, has a pattern in relief on its surface. The patterned roll 119 is configured to have a circular cylindrical surface 115, and a plurality of protrusions or pattern elements 116 that extend externally from the surface 115. The embossed pattern and the landing surfaces 118 in the pattern elements 116 may be of any appropriate configuration. The side walls 119 of the pattern elements 116 preferably form an angle similar to that described relative to the roll 110 shown in Figure 8. The rolls 110 and 112 are preferably operated in a manner that is the same or similar to that described above for the apparatus shown in Figure 8. (including, but not limited to, differential surface speed ranges between the rolls, range of gripping pressures between the rolls, optional possibility of heating one or both rolls, and the replacement of the rolls by other types of grip defining members The relief model, in the embodiment of the apparatuses shown in Figure 16, also comprises a plurality of spaced-apart model elements (p "model element segments") 116 having circular landing surfaces 118. In the embodiment of the method shown in Figure 16, however, the elements of models 116 are arranged in a configuration of "med." the moon. " The pattern elements 116 are provided in an alternating pattern wherein each other application of the joining pattern, junctions 94 are formed on opposite sides of the longitudinal axes, A1, of the covered "rope" of the absorbent material. The bonding process shown in the drawings penetrates through the tape of the absorbent material 1044 and autogenously bonds the first portion 1046A of the cover material to the second portion 1046B of the cover material 1046. The embodiments of the absorbent articles shown in the drawings demonstrate other advantages of the method of the present invention. The joints 94 can be placed in a limited number of models. These unions 94 can be used to create products that have a virtually unlimited number of possible geometric shapes. The joint patterns can also be used to add structural stability as well as to shape the absorbent article by adding a degree of inflexibility to the product along the line passing through the joints. This line can be rectilinear, curvilinear, or partially rectilinear and partially curvilinear. Deep padded impressions can be created by liquids that handle or appear. The method of the present invention can also be used to manufacture the line running at high speeds (example 700-1,000 feet per minute), and is not limited to particular models, as are the sewing processes. Figures 17 and 18 shown in sanitary napkin 1320 that can be produced with several different characteristics using the method of the present invention. Figure 17 shows an absorbent article (an extensible sanitary napkin designated 1320) in which the method of the present invention was used to simultaneously perform several different operations in the process of making the absorbent article. The sanitary napkin 1320 comprises a main body portion 1322. The main body portion 1322 comprises a liquid-permeable top sheet 1324, a liquid-impermeable backsheet 1326 attached to the topsheet, and an absorbent core 1328 positioned between the topsheet 1324 and backsheet 1326. These components can be joined in any appropriate manner that allows the assembled sanitary napkin 1320 to be extended. The sanitary napkin 1320 may comprise a pair of end seals 1329 that are formed by fusing the top sheet and the back sheet. The sanitary napkin 1320 shown in Figure 1320 also has wings or extensions 1330 extending from each longitudinal side edge of the main body portion 1322 thereof. The sanitary napkin 1320 shown in Figure 17 has an absorbent core 1328 with regions 1334 that have been formed into particle material 1336 by the method described herein. As shown in Figure 17, the regions 1334 comprising the particle material are separated by uniformed bands 1338 which are oriented in both longitudinal and transverse directions. In addition, the method of the present invention was preferably also used to form deformable network regions in top sheet 1324 and back sheet 1326. The term "deformable network region" is described in greater detail in U.S. Patent No. 5,518,801 entitled Network Materials Exhibiting Elastic Type Behavior, which was published on behalf of Chappel, et al. on May 21, 1996. The formation of the deformable net regions on the topsheet 1324 and the backsheet 1326 provide these components of the sanitary napkin with extensibility. The unformed webs of the deformable web in the topsheet 1324 and backsheet 1326 provide these extensible components with elastic-like properties. The formation of the absorbent core 1328 in particle material placed on the absorbent core 1328 in a shape that will not interfere with the extensibility of the topsheet 1324 or the backsheet 1326. The topsheet 1324 and the backsheet 1326 may be provided extensively in an address, in more than one direction, or in all directions of the XY plane, depending on the model of the deformable network formed in the present. In the embodiment shown in Figure 17, the sanitary towel 132o is extensible in both longitudinal and transverse directions. The sanitary napkin 1320 shown in Figure 17 is preferably extendable in the amounts specified in the disclosure of U.S. Patent 5,611,790 entitled "Constrained Absorbent Articles," which was published in the name of Osborn, et al. on March 18, 1997. Figure 17 shows that the methods described herein can also be used to provide wings or extensions 1330 with extensibility. The wings 1330 can be provided with extensibility in any of the directions specified above for the top sheet and the back sheet. It is also possible to provide the wings 1330 with extensibility in a direction or amount that differs from the upper and backsheet by passing the sanitary napkin 1320 through an apparatus having a different pattern on the portion of the patterned surface contacting them. wings 1330 of the portion of the apparatus contacting the main body portion of the absorbent article. The portions of the rolls that will be used to provide the wings with extensibility, if the calibrator rolls are used, they can also be placed together, or hooked to a greater extent, if the wings 1330 do not have as many layers as the main body portion 1322 has. The method of the present invention is also used for embossing and / or joining the components of the sanitary napkin. Figure 17 shows that the surface in contact with the body of the sanitary napkin 1320 can be provided with a plurality of reliefs in the form of fusion joints 1340. The fusion joints 1340 can be formed by providing a plurality of joint elements in the patterned surface of the apparatus used to form the absorbent core 1328 in particulate material. The joining elements can optionally be heated if desired. Typically, to join the components, at least those components that are attached will preferably comprise at least some thermoplastic material. In other embodiments, it may be desirable for the patterned surface to be provided with elements that merely highlight the surface in contact with the body of the sanitary napkin, and do not form fusion bonds between the components thereof. The method of the present invention can thus be used to form the absorbent core 1328 in particulate material, provide the upper sheet 1324 and back sheet 1326 with extensibility to provide the wings or extensions 1330 with extensibility, for embossing and / or joining the components and sealing the ends of the sanitary napkin 1320. All this can be accomplished in a single step by an apparatus similar to that shown in the drawings. Additionally, as shown in Figure 18, the joint model can penetrate the top sheet all the way to the backsheet to provide the absorbent material with integrity by dividing it. For example, the absorbent material may comprise a material placed by thermally attached air. In such a mode, it may not be necessary to provide conventional binder fibers or powdered binders to maintain the integrity of the material. The disclosures of all patents, patent applications (and any patents that are published thereof, as well as any corresponding published foreign patent applications), and the aforementioned publications of this entire disclosure are incorporated herein by reference herein. It is expressly not admitted, however, that any other document incorporated by reference herein teaches or discloses the present invention. While the particular embodiments of the present invention have been illustrated and described, it will be obvious to those skilled in the art that various other changes and modifications may be made without departing from the spirit and scope of the invention.
Claims (25)
1. A method for joining materials during the process of making an absorbent article, said method comprising the steps of: (a) providing a first material, said first material having a first unit capacity, a first surface and a second surface; said method characterized in that it further comprises (b) providing at least one other material having a bonding capacity that is greater than the first bonding capacity; (c) covering at least a portion of the first and second surfaces of said first material with said at least one material having a bonding capacity that is greater than the first bonding capacity; and (d) joining said material having a superior bonding capacity that covers at least a portion of said first surface of said first material to said material having a superior bonding capacity that covers at least a portion of said second surface. of said first material using the joints penetrating said first material.
The method of Claim 1, characterized in that said first material has at least a degree of Incompatibility with conventional bonding processes.
3. The method of claims 1 and 2, characterized in that said step (d) of joining said materials comprises the autogenously joining said materials.
4. A method according to any of the preceding claims, characterized in that the step (d) of joining said materials comprises the joining of said materials using pressure.
5. A method according to any of the preceding claims, characterized in that said first material comprises an absorbent foam material.
6. A method according to any of the preceding claims, characterized in that at least said other material is a network of nonwoven material.
A method according to any of the preceding claims, characterized in that at least one other material is a single network that is wrapped around both sides of the first material.
The method of Claims 1m 2, 3, 4 or 5, characterized in that at least one other material comprises a glue layer, or a polymeric cover.
9. A composite structure, characterized in that it comprises an absorbent material having at least a degree of incompatibility with conventional bonding processes, said incompatible material having a first bonding capacity and the first and second surfaces that are at least partially covered by I at least one material having a bonding capacity greater than said first bonding capacity, said composite structure comprising one or more autogenous connections joining a portion of the cover material which at least partially covers said first surface of said incompatible material to a portion of the cover material that at least partially covers said second surface of said incompatible material, said composite structure having a quilted appearance in the area of said joints.
10. A joining method by which an absorbent material having at least a degree of incompatibility with conventional joining processes during the process of making an absorbent article, said method comprises the steps of: a) providing an absorbent material that have at least a degree of incompatibility with conventional bonding processes, said absorbent material having a first bonding capacity, a first surface and a second opposing surface; said method characterized in that it additionally comprises b) providing at least one other material having a unit capacity that is greater than the first unit capacity; c) covering at least a portion of the first and second surfaces of said absorbent material with at least one material having a bonding capacity that is greater than the first bonding capacity; and d) applying a localized force to said covered absorbent material to displace said absorbent material at the place where said force was applied, said force causing said materials to have a bonding capacity that is greater than said first binding capacity resting on the opposing surfaces of said absorbent material to contact each characterized in that said absorbent material was placed; and e) joining said materials having a superior bonding capacity characterized in that said absorbent material was displaced.
The method of Claim 10, characterized in that said absorbent material has a breaking point that is less than the breaking point of the material having a greater bonding capacity, characterized in that said localized force is greater than the breaking point of the material. said absorbent material but less than the breaking point of said material having a higher unit capacity in such a way that the absorbent material fractures in at least one place without breaking the material having the superior bonding capacity.
12. The method according to Claim 11, characterized in that steps (d) and (e) of applying a localized force to displace said absorbent material and joining said materials having a higher bonding capacity occur in a single operation.
A method for joining the plural sheet, in which at least one of the sheets comprises thermoplastic material, said method comprising the steps of: (a) providing an anvil member and a relief-patterned grip member, said relief modeled member having a surface with elements of shapes extends outwardly therefrom, said method characterized in that said relief modeled member comprises a suitable material on its surface, said appropriate material at least partly surrounding at least some of these model elements; (b) advancing said sheet, with portions thereof in face-to-face relationship, by a pressure-biased grip between the anvil member and said embossed member; and (c) predisposing said grip defining the members toward one another under a pressure that is sufficient to compress at least a portion of said sheet and join at least some of said sheet to form a sheet without piercing said sheet.
14. A plural sheet joining method, at least one of the sheets comprises thermoplastic material, said method comprising the steps of: a) providing an anvil member and an embossing pattern defining member, said member modeled on Emboss that has a surface with elements of forms extends to the outside from the same b) provide the sheet, with portions thereof in face-to-face relationship, said method comprising c) compressing at least the portions of said sheets in regions of said sheets where the joints will be formed; and d) predisposing said grip defining the members toward one another under a pressure that is sufficient for said pattern elements to join at least some of said sheet to form a sheet without piercing said sheet.
The method of Claim 14, characterized in that the step (c) of compressing occurs prior to joining in step (d).
The method of Claim 14, characterized in that the step (c) of compressing occurs simultaneously with the joint in step (d).
17. A method according to claims 13, 14, or 17, characterized in that said sheets have a combined gauge of greater than or equal to about 2 mm.
18. A plural method for bonding sheets, at least one of the sheets comprises thermoplastic material, said method comprising the steps of: a) providing an anvil member and a relief-patterned grip member, said relief modeling member having a surface with elements of shapes extending outwards therefrom, said method characterized in that at least one of said anvil member and said embossing member comprises at least one bearing member, said at least one bearing member having a height that is sufficient to maintain contact with at least a portion of the surface of said anvil member when said modeling member and said anvil member are in said grip defining the relationship: * tb) forward said sheet, with portions thereof in face-to-face relationship, by a grip predisposed by pressure between the anvil member and said model member Embossed; and c) predisposing said grip defining the members toward one another under a pressure that is sufficient for at least some of said pattern elements to join at least some of said sheets to form a laminate.
The method of claim 19, characterized in that the anvil member and the embossed member comprise rotating rolls.
The method of claim 20, characterized in that at least said bearing member comprises a continuous ring around the circumference of at least said anvil member and said embossed member.
The method of claims 20 and 21, characterized in that there are differences in the surface areas of said model elements around the circumference of said patterned roll, and the surface area of said at least one bearing member is selected to balance the differences in the surface areas of said pattern elements around said modeling member.
22. The method of claim 21 characterized in that at least said bearing member has at least one cutting area therein.
23. The method of claim 23 characterized in that said model elements have terrains with a surface area, and at least said cutting area has a plan view size that is equal to the surface area of the terrains of the elements of Models.
The method of claims 20 and 21 characterized in that at least said bearing member maintains a preselected minimum distance • * • s between the axis of said anvil member and the axis of said modeled member, even when said model elements have spaces in the middle.
25. The method of claim 20 and 21 characterized in that at least said bearing member maintains said anvil member and said molded member in contact even when said model elements have spaces in the middle.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08979979 | 1997-11-26 | ||
| US08979980 | 1997-11-26 | ||
| US09031352 | 1998-02-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| MXPA00005238A true MXPA00005238A (en) | 2001-07-03 |
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