The present disclosure relates to methods for manufacturing absorbent articles, and more particularly, to apparatuses and methods for making leg cuffs for diapers.
Along an assembly line, various types of articles, such as for example, diapers and other absorbent articles, may be assembled by adding components to and/or otherwise modifying an advancing, continuous web of material. For example, in some processes, advancing webs of material are combined with other advancing webs of material. In other examples, individual components created from advancing webs of material are combined with advancing webs of material, which in turn, are then combined with other advancing webs of material. In some cases, individual components created from advancing web or webs are combined with other individual components created from other advancing web or webs. Webs of material and component parts used to manufacture diapers may include: backsheets, topsheets, leg cuffs, waist bands, absorbent core components, front and/or back ears, fastening components, and various types of elastic webs and components such as leg elastics, barrier leg cuff elastics, stretch side panels, and waist elastics. Once the desired component parts are assembled, the advancing web(s) and component parts are subjected to a final knife cut to separate the web(s) into discrete diapers or other absorbent articles.
Current diaper designs may include inner barrier leg cuffs and/or outer barrier leg cuffs. The inner barrier leg cuffs may help prevent leakage of bodily exudates, such as urine and fecal matter, and the outer barrier leg cuffs may help provide a covering over the inner barrier leg cuff to minimize the visibility of exudates through the inner barrier leg cuff. The outer barrier leg cuffs may also help provide a secondary means to capture bodily exudates that may breach the inner barrier leg cuffs. The inner barrier leg cuff may be made of various materials, such as hydrophobic nonwovens, and may be disposed on a body-facing surface of the absorbent article or may be connected to the body-facing surface of a film backsheet layer. The inner barrier leg cuff may be a substantially liquid impervious layer to help prevent bodily exudates from passing out of the sides of the absorbent article and may also be highly breathable, allowing outside air to reach the skin to help maintain a healthy level of skin hydration. Some leg cuffs may include the elastic strands, which create the contraction forces and gathers.
In some leg cuff configurations, elastic strands are bonded to substrates, such as one or more nonwoven layers. And the substrates may extend the entire length of the diaper, such as from the front waist edge to the rear waist edge. In addition, the elastic strands may not extend the full length of the diaper. In order to manufacture such a leg cuff arrangement, continuous lengths of stretched elastic strands may be intermittently bonded the continuous lengths of advancing substrates to create an elastic laminate having intermittently spaced regions where the elastics are bonded to the substrates and intermittently spaced regions where the elastics are not bonded to the substrates. In turn, the elastic laminate may be bonded to a continuous length of advancing webs, which may be assembled into a continuous length of advancing diapers. As mentioned above, the advancing webs and component parts may be subjected to a final knife cut to separate the webs into discrete diapers. The final knife cut may also be configured to cut the elastics in the laminate in regions where the elastics are not bonded to the substrates. As such, it may be intended that the severed ends of the elastics retract or snap back to the regions where the elastics are bonded to the substrates. However, in some manufacturing processes, the elastics inadvertently become bonded to other component parts of the absorbent articles during the manufacturing process. For example, in some embodiments, distal end portions of the leg cuffs may be bonded, referred to herein as “tack-down bonds,” to the topsheet of the diaper in the front and/or rear waist regions. And as such, some elastics may become ensnared in the tack-down bonds, and thus, the severed elastic ends may not retract fully to the desired position on the leg cuffs. Such unretracted elastic strand ends may be detrimental to the aesthetic appearances of the diapers and/or may have a detrimental effect on leg cuff functionality.
Consequently, it would be beneficial to provide methods and apparatuses that are configured to create leg cuffs to help maximize the aesthetic appearance of the leg cuff when placed in an assembled product as well as help provide a more consistent manufacturing process.
The present disclosure relates to methods and apparatuses for assembling absorbent articles that include leg cuff gasketing assemblies. As discussed in more detail below, each leg gasketing assembly may be formed from elastic laminates having stretched elastic strands intermittently bonded thereto. As such, the elastic laminate includes bonded regions and non-bonded regions intermittently spaced along the machine direction. The elastic strands are then intermittently deactivated by severing the strands in the non-bonded regions of the continuous elastic laminate to form continuous lengths of leg gasketing assemblies having elastic regions and deactivated regions. The continuous lengths of leg gasketing assemblies may then bonded to a continuous topsheet substrate. In some embodiments, the elastic laminate may be combined with the topsheet substrate before severing the strands in the non-bonded regions.
In one form, a method for assembling disposable absorbent articles includes the steps of: advancing a continuous topsheet substrate having a first surface and an opposing second surface in a machine direction; advancing a continuous leg cuff substrate having a first surface and an opposing second surface in the machine direction, and defining a width in a cross direction, wherein the leg cuff substrate includes opposing first and second longitudinal edges and laterally opposed first and second edge regions separated by a central region; advancing elastic strands in the machine direction in a stretched state; intermittently bonding the elastic strands in the stretched state to the first surface of the leg cuff substrate; folding the first edge region of the leg cuff substrate onto a portion of either the first edge region, the central region, or the second edge region of the leg cuff substrate such that the stretched elastic strands are positioned between the first surface of the folded first edge region and the first surface of the portion of either the first edge region, the central region, or the second edge region to form an elastic laminate, the elastic laminate including bonded regions and non-bonded regions intermittently spaced along the machine direction, wherein the elastic strands are bonded to the leg cuff substrate in the bonded regions, and wherein the elastic strands are not bonded to the leg cuff substrate in the non-bonded regions; severing elastic strands in the non-bonded regions of the elastic laminate to form a continuous length of leg gasketing assemblies having elastic regions intermittently spaced along the machine direction between deactivated regions; bonding the continuous length of leg gasketing assemblies with the continuous topsheet substrate; and cutting the continuous topsheet substrate and continuous length of leg gasketing assemblies along the cross direction in deactivated regions.
In another form, a method for assembling disposable absorbent articles includes the steps of: advancing a continuous topsheet substrate having a first surface and an opposing second surface in a machine direction; advancing elastic strands in the machine direction in a stretched state; intermittently bonding the elastic strands in the stretched state between a first substrate layer and a second substrate layer to form an elastic laminate; the elastic laminate including bonded regions and non-bonded regions intermittently spaced along the machine direction, wherein the elastic strands are bonded to the first substrate layer in the bonded regions, and wherein the elastic strands are not bonded to the first substrate layer and the second substrate layer in the non-bonded regions; severing elastic strands in the non-bonded regions of the elastic laminate to form a continuous length of leg gasketing assemblies having elastic regions intermittently spaced along the machine direction between deactivated regions; and bonding the first substrate layer with the continuous topsheet substrate.
In yet another form, a method may be configured to assemble disposable absorbent articles, each absorbent article comprising a chassis include a topsheet, a backsheet, and an absorbent core positioned between the backsheet and the topsheet, and leg gasketing assemblies bonded with chassis. The method includes the steps of: advancing a continuous topsheet substrate in a machine direction; advancing a continuous leg cuff substrate in the machine direction; advancing elastic strands in the machine direction in a stretched state; intermittently bonding the elastic strands in the stretched state to the leg cuff substrate to form an elastic laminate, the elastic laminate including bonded regions and non-bonded regions intermittently spaced along the machine direction, wherein the elastic strands are bonded to the leg cuff substrate in the bonded regions, and wherein the elastic strands are not bonded to the leg cuff substrate; severing elastic strands in the non-bonded regions of the elastic laminate to form a continuous length of leg gasketing assemblies having elastic regions intermittently spaced along the machine direction between deactivated regions; bonding the continuous leg cuff substrate with the continuous topsheet substrate; and cutting the continuous topsheet substrate and continuous leg cuff substrate along a cross direction in deactivated regions.
FIG. 6A1 is a cross-sectional view of the substrates and elastics from
FIG. 6A2 is a cross-sectional view of the substrates and elastics from
FIG. 6B1 is a cross-sectional view of the substrates and elastics from
FIG. 6B2 is a cross-sectional view of the substrates and elastics from
FIG. 6D1 is a cross-sectional view of the substrates and elastics from
FIG. 6D2 is a cross-sectional view of the substrates and elastics from
FIG. 6E1 is a cross-sectional view of the substrates and elastics from
The following term explanations may be useful in understanding the present disclosure:
“Absorbent article” is used herein to refer to consumer products whose primary function is to absorb and retain soils and wastes. “Diaper” is used herein to refer to an absorbent article generally worn by infants and incontinent persons about the lower torso. The term “disposable” is used herein to describe absorbent articles which generally are not intended to be laundered or otherwise restored or reused as an absorbent article (e.g., they are intended to be discarded after a single use and may also be configured to be recycled, composted or otherwise disposed of in an environmentally compatible manner).
“Body-facing” and “garment-facing” refer respectively to the relative location of an element or a surface of an element or group of elements. “Body-facing” implies the element or surface is nearer to the wearer during wear than some other element or surface. “Garment-facing” implies the element or surface is more remote from the wearer during wear than some other element or surface (i.e., element or surface is proximate to the wearer's garments that may be worn over the disposable absorbent article).
An “elastic,” “elastomer” or “elastomeric” refers to materials exhibiting elastic properties, which include any material that upon application of a force to its relaxed, initial length can stretch or elongate to an elongated length more than 10% greater than its initial length and will substantially recover back to about its initial length upon release of the applied force.
As used herein, the term “joined” encompasses configurations whereby an element is directly secured to another element by affixing the element directly to the other element, and configurations whereby an element is indirectly secured to another element by affixing the element to intermediate member(s) which in turn are affixed to the other element.
“Longitudinal” means a direction running substantially perpendicular from a waist edge to a longitudinally opposing waist edge of an absorbent article when the article is in a flat out, uncontracted state, or from a waist edge to the bottom of the crotch, i.e. the fold line, in a bi-folded article. Directions within 45 degrees of the longitudinal direction are considered to be “longitudinal.” “Lateral” refers to a direction running from a longitudinally extending side edge to a laterally opposing longitudinally extending side edge of an article and generally at a right angle to the longitudinal direction. Directions within 45 degrees of the lateral direction are considered to be “lateral.”
The term “substrate” is used herein to describe a material which is primarily two-dimensional (i.e. in an XY plane) and whose thickness (in a Z direction) is relatively small (i.e. 1/10 or less) in comparison to its length (in an X direction) and width (in a Y direction). Non-limiting examples of substrates include a web, layer or layers or fibrous materials, nonwovens, films and foils such as polymeric films or metallic foils. These materials may be used alone or may comprise two or more layers laminated together. As such, a web is a substrate.
The term “nonwoven” refers herein to a material made from continuous (long) filaments (fibers) and/or discontinuous (short) filaments (fibers) by processes such as spunbonding, meltblowing, carding, and the like. Nonwovens do not have a woven or knitted filament pattern.
The term “machine direction” (MD) is used herein to refer to the direction of material flow through a process. In addition, relative placement and movement of material can be described as flowing in the machine direction through a process from upstream in the process to downstream in the process.
The term “cross direction” (CD) is used herein to refer to a direction that is generally perpendicular to the machine direction.
The term “pant” (also referred to as “training pant”, “pre-closed diaper”, “diaper pant”, “pant diaper”, and “pull-on diaper”) refers herein to disposable absorbent articles having a continuous perimeter waist opening and continuous perimeter leg openings designed for infant or adult wearers. A pant can be configured with a continuous or closed waist opening and at least one continuous, closed, leg opening prior to the article being applied to the wearer. A pant can be preformed by various techniques including, but not limited to, joining together portions of the article using any refastenable and/or permanent closure member (e.g., seams, heat bonds, pressure welds, adhesives, cohesive bonds, mechanical fasteners, etc.). A pant can be preformed anywhere along the circumference of the article in the waist region (e.g., side fastened or seamed, front waist fastened or seamed, rear waist fastened or seamed.
“Pre-fastened” refers herein to pant diapers manufactured and provided to consumers in a configuration wherein the front waist region and the back waist region are fastened or connected to each other as packaged, prior to being applied to the wearer. As such pant diapers may have a continuous perimeter waist opening and continuous perimeter leg openings designed for infant or adult wearers. As discussed in more detail below, a diaper pant can be preformed by various techniques including, but not limited to, joining together portions of the diaper using refastenable and/or permanent closure members (e.g., seams, heat bonds, pressure welds, adhesives, cohesive bonds, mechanical fasteners, etc.). In addition, pant diapers can be preformed anywhere along the circumference of the waist region (e.g., side fastened or connected, front waist fastened or connected, rear waist fastened or connected). U.S. Pat. No. 6,120,487 provides examples of a diaper having a pre-formed waist opening and leg openings.
The present disclosure relates to methods and apparatuses for assembling absorbent articles, and more particularly, diapers that include leg cuff gasketing assemblies including an inner barrier leg cuff and an outer barrier leg cuff. As discussed in more detail below, each leg gasketing assembly may be formed from first and second elastic laminates having stretched elastic strands intermittently bonded thereto. An elastic laminate may be formed by intermittently bonding elastic strands between a first continuous substrate layer and a second continuous substrate layer. In some embodiments, the elastic laminate may be formed by intermittently bonding elastic strands onto portions of a single continuous substrate that are folded over the elastic strands and onto other portions of the substrate. As such, the elastic laminate includes bonded regions and non-bonded regions intermittently spaced along the machine direction, wherein the elastic strands are bonded to the substrate in the bonded regions, and wherein the elastic strands are not bonded to the substrate substrate in the non-bonded regions. The elastic strands are then intermittently deactivated by severing the strands in the non-bonded regions of the continuous elastic laminate to form continuous lengths of leg gasketing assemblies having elastic regions and deactivated regions. The continuous lengths of leg gasketing assemblies may then bonded to a continuous topsheet substrate. Bonds, referred to herein as tack-down bonds, may then be applied to bond portions of the leg gasketing assemblies in the non-bonded regions with the topsheet substrate. The topsheet substrate may be combined with other components to form a continuous length of absorbent articles. And discrete diapers may then be formed by separating the continuous absorbent articles with a final knife cut. It is to be appreciated that the methods and apparatuses herein may be configured to perform assembly operations in various different orders. For example, in some embodiments, the elastic laminate may be combined with the topsheet substrate before severing the strands in the non-bonded regions.
It is to be appreciated that the elastic laminate can be formed in various ways. For example, in some embodiments, the first continuous substrate layer may be formed from a first continuous substrate, and the second continuous substrate layer may be formed from a second continuous substrate. In other embodiments, the first continuous substrate layer and/or the second continuous substrate layer may be formed by folding a portion of a single continuous substrate onto another portion of the single continuous substrate.
The processes and apparatuses discussed herein may be used to assemble elastic laminates with various types of substrate configurations, some of which may be used in the manufacture of different types of absorbent articles. To help provide additional context to the subsequent discussion of the process embodiments, the following provides a general description of absorbent articles in the form of diapers that include elastic laminates that may be assembled in accordance with the methods and apparatuses disclosed herein. Although the methods and apparatuses herein are discussed below in the context of manufacturing leg gasketing assemblies for absorbent articles, it is to be appreciated that the assembly methods and apparatuses herein may be configured to manufacture various types of substrates having intermittently spaced elastic and inelastic regions.
The outer periphery of chassis 22 is defined by longitudinal edges 12 and lateral edges 14. The longitudinal edges 12 may be subdivided into a front longitudinal edge 12a, which is the portion of the longitudinal edge 12 in the first waist region 36, and a rear longitudinal edge 12b, which is the portion of the longitudinal edge 12 in the rear waist region 38. The chassis 22 may have opposing longitudinal edges 12 that are oriented generally parallel to the longitudinal centerline 100. In some embodiments, the longitudinal edges 12 may be curved or angled to produce, for example, an “hourglass” shape diaper when viewed in a plan view. The chassis 22 may have opposing lateral edges 14 that are oriented generally parallel to the lateral centerline 110.
The chassis 22 may comprise a liquid permeable topsheet 24, a backsheet 26, and an absorbent core 28 between the topsheet 24 and the backsheet 26. The absorbent core 28 may have a body-facing surface and a garment facing-surface. The topsheet 24 may be joined to the core 28 and/or the backsheet 26. The backsheet 26 may be joined to the core 28 and/or the topsheet 24. It should be recognized that other structures, elements, or substrates may be positioned between the core 28 and the topsheet 24 and/or backsheet 26. In some embodiments, the chassis 22 comprises the main structure of the absorbent article 20 with other features added to form the composite diaper structure. It is to be appreciated that the topsheet 24, the backsheet 26, and the absorbent core 28 may be assembled in a variety of configurations, such as for example, described generally in U.S. Pat. Nos. 3,860,003; 5,151,092; 5,221,274; 5,554,145; 5,569,234; 5,580,411; and 6,004,306.
It is to also be appreciated that a portion or the whole of the diaper 20 may also be made laterally extensible. The additional extensibility may help allow the diaper 20 to conform to the body of a wearer during movement by the wearer. The additional extensibility may also help, for example, allow the user of the diaper 20 including a chassis 22 having a particular size before extension to extend the front waist region 36, the back waist region 38, or both waist regions of the diaper 20 and/or chassis 22 to provide additional body coverage for wearers of differing size, i.e., to tailor the diaper to an individual wearer. Such extension of the waist region or regions may give the absorbent article a generally hourglass shape, so long as the crotch region is extended to a relatively lesser degree than the waist region or regions, and may impart a tailored appearance to the article when it is worn.
As previously mentioned, the diaper 20 may include a backsheet 26. The backsheet 26 may also define the outer, garment facing surface 120 of the chassis 22. The backsheet 26 may be impervious to fluids (e.g., menses, urine, and/or runny feces) and may be manufactured from a thin plastic film, although other flexible liquid impervious materials may also be used. The backsheet 26 may prevent the exudates absorbed and contained in the absorbent core from wetting articles which contact the diaper 20, such as bedsheets, pajamas and undergarments. The backsheet 26 may also comprise a woven or nonwoven material, polymeric films such as thermoplastic films of polyethylene or polypropylene, and/or a multi-layer or composite materials comprising a film and a nonwoven material (e.g., having an inner film layer and an outer nonwoven layer). The backsheet may also comprise an elastomeric film. An example backsheet 26 may be a polyethylene film having a thickness of from about 0.012 mm (0.5 mils) to about 0.051 mm (2.0 mils). Exemplary polyethylene films are manufactured by Clopay Corporation of Cincinnati, Ohio, under the designation BR-120 and BR-121 and by Tredegar Film Products of Terre Haute, Ind., under the designation XP-39385, X15306, X10962, and X10964. The backsheet 136 may also be embossed and/or matte-finished to provide a more clothlike appearance. Further, the backsheet 26 may permit vapors to escape from the absorbent core (i.e., the backsheet is breathable) while still preventing exudates from passing through the backsheet 26. The size of the backsheet 26 may be dictated by the size of the absorbent core 28 and/or particular configuration or size of the diaper 20.
Also described above, the diaper 20 may include a topsheet 24. The topsheet 24 may also define all or part of the inner, body facing surface 121 of the chassis 22. The topsheet 24 may be compliant, soft feeling, and non-irritating to the wearer's skin. It may be elastically stretchable in one or two directions. Further, the topsheet 24 may be liquid pervious, permitting liquids (e.g., menses, urine, and/or runny feces) to penetrate through its thickness. A topsheet 24 may be manufactured from a wide range of materials such as woven and nonwoven materials; apertured or hydroformed thermoplastic films; apertured nonwovens, porous foams; reticulated foams; reticulated thermoplastic films; and thermoplastic scrims. Woven and nonwoven materials may comprise natural fibers such as wood or cotton fibers; synthetic fibers such as polyester, polypropylene, or polyethylene fibers; or combinations thereof. If the topsheet 24 includes fibers, the fibers may be spunbond, carded, wet-laid, meltblown, hydroentangled, or otherwise processed as is known in the art.
Topsheets 24 may be selected from high loft nonwoven topsheets, apertured film topsheets and apertured nonwoven topsheets. Apertured film topsheets may be pervious to bodily exudates, yet substantially non-absorbent, and have a reduced tendency to allow fluids to pass back through and rewet the wearer's skin. Exemplary apertured films may include those described in U.S. Pat. Nos. 5,628,097; 5,916,661; 6,545,197; and 6,107,539.
As mentioned above, the diaper 20 may also include an absorbent core 28 that is joined to the chassis 22. The absorbent core 28 may additionally include one or more absorbent cores or absorbent core layers. The absorbent core 28 may be at least partially disposed between the topsheet 24 and the backsheet 26 and may be formed in various sizes and shapes that are compatible with the diaper. Exemplary absorbent structures for use as the absorbent core of the present disclosure are described in U.S. Pat. Nos. 4,610,678; 4,673,402; 4,888,231; and 4,834,735; 4,888,231; 5,137,537; 5,147,345; 5,342,338; 5,260,345; 5,387,207; 5,397,316; and 5,625,222.
Some absorbent core embodiments may comprise fluid storage cores that contain reduced amounts of cellulosic airfelt material. For instance, such cores may comprise less than about 40%, 30%, 20%, 10%, 5%, or even 1% of cellulosic airfelt material. Such a core may comprises primarily absorbent gelling material in amounts of at least about 60%, 70%, 80%, 85%, 90%, 95%, or even about 100%, where the remainder of the core comprises a microfiber glue (if applicable). Such cores, microfiber glues, and absorbent gelling materials are described in U.S. Pat. Nos. 5,599,335; 5,562,646; 5,669,894; and 6,790,798 as well as U.S. Patent Publication Nos. 2004/0158212 and 2004/0097895.
As shown in
The ears 40, 42 may be in the form of a discrete ear that is formed as separate element which is joined to the chassis 22. The ears may also be in the form of an integral ear that is a portion of the chassis 22 that projects laterally outward from the longitudinal edge 12. The integral ear may be formed by cutting the chassis form to include the shape of the ear projection.
The absorbent article 20 may also include a fastening system 50. When fastened, the fastening system 50 interconnects the first waist region 36 and the rear waist region 38 resulting in a waist circumference that may encircle the wearer during wear of the absorbent article 20. The fastening system 50 may comprise a fastener such as tape tabs, hook and loop fastening components, interlocking fasteners such as tabs & slots, buckles, buttons, snaps, and/or hermaphroditic fastening components, although any other known fastening means are generally acceptable. Some exemplary surface fastening systems are disclosed in U.S. Pat. Nos. 3,848,594; 4,662,875; 4,846,815; 4,894,060; 4,946,527; 5,151,092; and 5,221,274. An exemplary interlocking fastening system is disclosed in U.S. Pat. No. 6,432,098. The fastening system 50 may also provide a means for holding the article in a disposal configuration as disclosed in U.S. Pat. No. 4,963,140. The fastening system 50 may also include primary and secondary fastening systems, as disclosed in U.S. Pat. No. 4,699,622. The fastening system 50 may be constructed to reduce shifting of overlapped portions or to improve fit as disclosed in U.S. Pat. Nos. 5,242,436; 5,499,978; 5,507,736; and 5,591,152.
As previously mentioned and as shown in
As shown in
As shown in
With continued reference to
It is to be appreciated that the elastic members 77, 78 may be located various distances with respect to various features of the leg gasketing assembly and/or may be located various distances with respect to each other. For example, in some embodiments, some of the elastic members 77 may separated from each other by 1 mm, 2 mm, 3 mm, 3.5 mm, 4 mm, or more. And for example, in some embodiments, some or all the elastic members 78 may separated from each other by 1 mm, 2 mm, 3 mm, 3.5 mm, 4 mm, or more.
As shown in
As previously mentioned, the diaper 20 may include an opacity strengthening patch 80. The opacity strengthening patch 80 may be connected to the leg gasketing assembly 70, the polymeric film layer, or the backsheet 26. The opacity strengthening patch 80 may be positioned between the backsheet 26 and leg gasketing assemblies 70 in either the first waist region 36, the second waist region 38, or both the first waist region 36 and the second waist region 38 of the article; the opacity strengthening patch 80 may overlap at least one of the leg gasketing assembly 70 or the polymeric film layer using various techniques, such as glue, mechanical bonds, thermal bonds, or the like. The opacity strengthening patch may help prevent the article from extending excessively during application and wearing; and may also provide opacity at the sides and waist to help prevent the skin of the user from showing through the article. Thus, the patch 80 may be located at any portion of the chassis where strength and opacity is desirable. In some embodiments, the opacity strengthening patch may include materials having a basis weight of at least about 10 gsm, at least about 15 gsm, or at least about 25 gsm.
As discussed in more detail below, the leg gasketing assembly 70 may be constructed from a single substrate or web of material. In some embodiments, the substrate may include a first material corresponding with the inner barrier leg cuff 71 and a second material corresponding with the outer cuff 74. The first and second materials may overlap and may be joined together along a longitudinal edge of each material in various ways.
It is to be appreciated that the leg gasketing assembly 70 may also be constructed from various types of materials. For example, the leg gasketing assembly 70 may be made from a substantially liquid impervious material, such as for example, an SMS nonwoven, SMMS nonwoven material, or a nonwoven component layer comprising “N-fibers”. Various nonwoven fabric webs may comprise spunbond, meltblown, spunbond (“SMS”) webs comprising outer layers of spunbond thermoplastics (e.g., polyolefins) and an interior layer of meltblown thermoplastics. In some embodiments, the leg gasketing assembly 70 may include a nonwoven component layer having fine fibers (“N-fibers”) with an average diameter of less than 1 micron and (an “N-fiber layer”) may be added to, or otherwise incorporated with, other nonwoven component layers to form a nonwoven web of material. In some embodiments, the N-fiber layer may be used to produce a SNS nonwoven web or SMNS nonwoven web, for example.
In some embodiments, the leg gasketing assembly 70 may include a first nonwoven component layer comprising fibers having an average diameter in the range of about 8 microns to about 30 microns, a second nonwoven component layer comprising fibers having a number-average diameter of less than about 1 micron, a mass-average diameter of less than about 1.5 microns, and a ratio of the mass-average diameter to the number-average diameter less than about 2, and a third nonwoven component layer comprising fibers having an average diameter in the range of about 8 microns to about 30 microns. The second nonwoven component layer is disposed intermediate the first nonwoven component layer and the third nonwoven component layer. In some embodiments, the leg gasketing assembly substrate may have various basis weights, such as for example, about 10 gsm; 13 gsm; 15 gsm; or 18 gsm.
The N-fibers may be include a polymer, for example, selected from polyesters, including PET and PBT, polylactic acid (PLA), alkyds, polyolefins, including polypropylene (PP), polyethylene (PE), and polybutylene (PB), olefinic copolymers from ethylene and propylene, elastomeric polymers including thermoplastic polyurethanes (TPU) and styrenic block-copolymers (linear and radial di- and tri-block copolymers such as various types of Kraton), polystyrenes, polyamides, PHA (polyhydroxyalkanoates) and e.g. PHB (polyhydroxubutyrate), and starch-based compositions including thermoplastic starch, for example. The above polymers may be used as homopolymers, copolymers, e.g., copolymers of ethylene and propylene, blends, and alloys thereof. The N-fiber layer may be bonded to the other nonwoven component layers by any suitable bonding technique, such as the calender bond process, for example, also called thermal point bonding.
The inner barrier cuff 71 and/or outer cuff 74 may be treated, in full or in part, with a lotion, as described above with regard to topsheets, or may be fully or partially coated with a hydrophobic surface coating as detailed in U.S. Pat. No. 7,626,073. Hydrophobic surface coatings usefully herein may include a nonaqueous, solventless, multicomponent silicone composition. The silicone composition includes at least one silicone polymer and is substantially free of aminosilicones.
It is to be appreciated that the leg gasketing assemblies may be bonded to various components of the diaper 20 in various locations. For example, in some embodiments, the leg gasketing assembly may be spaced laterally inward of the chassis edge 12 by about 10 mm, about 20 mm, or about 30 mm. In some embodiments, the laterally outboard edge of the chassis 12 may be defined by a lateral edge of the outer leg cuff 74. In some embodiments, the backsheet 26 may be spaced laterally inward of the outer cuff edge by about 10 mm; about 20 mm; about 30 mm; or about 40 mm. In some embodiments, the laterally outboard edge of the leg gasketing assembly 70 may be disposed laterally inboard at least a portion of the longitudinal edge of the article in at least one of the waist regions. Thus, in one embodiment, the front ears 40 and/or back ears 42 extend laterally outward further than the leg gasketing assembly 70. It is also to be appreciated that the leg gasketing assembly 70 may be connected with the diaper in various ways. For example, in some embodiments, the leg gasketing assembly may be joined to the topsheet 24 and/or backsheet 26 with a slot coated adhesive. Such slot coated adhesive may be applied in various quantities. For example, in some embodiments, at least about 12 gsm, 15 gsm, 20 gsm, 25 gsm, 40 gsm, or 60 gsm of adhesive may be applied. In some embodiments, the leg gasketing assembly may be joined with the topsheet and/or backsheet by spiral adhesive sprays.
As previously mentioned, the apparatuses and methods according to the present disclosure may be utilized to assemble various components of absorbent articles in the form of diapers 20. For example,
As described in more detail below, the converting apparatus 300 shown in
As shown in
With continued reference to
It is to be appreciated that various sized portions of the cuff substrate 400 may be folded in various ways. For example, as shown in FIGS. 6B and 6B2, the cuff substrate 400 is folded such that the first longitudinal edge 402a and the second longitudinal edge 402b are positioned adjacent to each other and in some embodiments, may abut each to other. In other embodiments, the cuff substrate 400 may be folded so as to define a gap or space between the first longitudinal edge 402a and the second longitudinal edge 402b. In yet other embodiments, the cuff substrate 400 may be folded such that the first longitudinal edge 402a and/or second longitudinal edge 402b are in positioned in an overlapping arrangement. For example, the second longitudinal edge 402b may be folded over the first longitudinal edge 402a.
It should also be appreciated steps of combining the elastics 77, 78 with the cuff substrate 400 can be ordered in various ways. For example, the apparatus 300 may be configured to combine the outer cuff elastics 77 with the cuff substrate 400 before combining the inner cuff elastics 78 with the cuff substrate 400. In another example, the apparatus may be configured to combine the outer cuff elastics 77 and the inner cuff elastics 78 with the cuff substrate 400 at the same time. Although the embodiments described illustrate leg cuff assemblies 70 made from a single cuff substrate 400 combined with elastics 77, 78 and wherein the cuff substrate is folded onto itself, it is to be appreciated that the leg cuff assemblies can be formed by combining separate continuous lengths of cuff substrate material with elastic strands 77, 78. It should also be appreciated that the assembly process may be configured such a single substrate that is longitudinally slit along the machined direction and separated in the cross direction CD into two separate leg cuff substrates 400. In addition, the assembly process can be configured that the elastics 77, 78 are combined with the single substrate before or after the slitting operation.
As discussed above, the inner cuff elastic strands 78 and the outer cuff elastic strands 77 are intermittently bonded to the continuous lengths of cuff substrate 400 along the machine direction MD. For example,
Referring back to
It is to be appreciated that the cutting unit 312 may be arranged to cut the elastics in different configurations. For example, in some embodiments, the cutting unit 312 may operate to sever only the inner cuff elastics 77 without severing the outer cuff elastics 78. In other embodiments, the cutting unit 312 may operate to sever only the outer cuff elastics 78 without severing the inner cuff elastics 77.
It is to be appreciated that various configurations of cutting units 312 can be used with the apparatuses and methods herein. Such cutting unit configurations may include features of the cutting knives/units disclosed, for example, in U.S. Pat. Nos. 5,393,360; 7,708,849; 7,861,756; 7,777,094; U.S. patent application Ser. No. 13/434,912, filed on Mar. 30, 2012, further identified by Attorney Docket Number 12394; and U.S. Patent Application No. 61/617,713, filed on Mar. 30, 2012, further identified by Attorney Docket Number AA833FP-AF. As such, the cutting units may be configured with die knife, flexible blade, and/or compression roll features, and may also include additional features to control knife-anvil gaps and/or force.
As shown in
It is to be appreciated that the elastic laminates 403 may be arranged in various ways on the cutting unit 312. For example, as shown in
It is to be appreciated that the cutting unit 312 may be configured with various quantities of blades having various shapes and orientations. For example, the cutting unit 312 shown in
In addition, the first blade 612a and the second blade 612b, as well as the third and fourth blades 612c, 612d, may define different lengths, L, and may separated from each other by various distances in the cross direction CD. In addition, the blades 612 may be configured to cut the elastics 77, 78 simultaneously in the CD direction along in a substantially straight line. It is also to be appreciated that the cutting roll 600 may be configured with more than or less than two blades 612 aligned along the CD direction of outer circumferential surface 606 of the cutting roll 600. For example, in some embodiments, instead of having the first blade 612a and the second blade 612b, the cutting roll 600 may be configured with a single blade 612 extending along the CD direction for a length, L, on the outer circumferential surface 606.
With reference to
It is to be appreciated that the nip rolls 314 illustrated in
As shown in
As previously mentioned, it is to be appreciated that the methods and apparatuses herein may be configured to perform assembly operations in various different orders. For example, the apparatus 300 in
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”
Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.