Patent Application
20200261281
The present invention relates to pant-type wearable articles having an elastic belt with improved regularity of gathers, and improved sweat management.
Infants and other incontinent individuals wear absorbent articles such as diapers to receive and contain urine and other body exudates. Pull-on absorbent articles, or pant-type absorbent articles, are those which are donned by inserting the wearer's legs into the leg openings and sliding the article up into position about the lower torso. Pant-type absorbent articles have become popular for use on children who are able to walk and often who are toilet training, as well as for younger children who become more active in movement such that application of taped-type absorbent articles tends to be more difficult, and also for younger babies requiring a soft fit around the waist opening and leg openings.
Pant-type articles may take various structures wherein the circumference of the waist opening and vicinity thereof is made elastic enough to facilitate the wearer or the caregiver to expand the article and insert the wearer's legs into the leg openings for wearing the article. The region of the waist circumference and vicinity thereof is often referred to as the elastic belt. One type of structure for the pant-type article is the belt-type pant having a central chassis to cover the crotch region of the wearer and a separate elastic belt defining the waist opening and leg opening, such as described in PCT Publication WO 2006/17718A. Another type of structure for the pant-type article is the uni-body pant configured such that the outer cover of the article completely covers the entirety of the garment-facing surface of the article, wherein the portion configured to stretch about the torso is considered the elastic belt region.
Whatever the structure of the pant-type article may be, pant-type articles provide only a very small range of size adjustment or body configuration adjustment based on the structural limitations of the article. As such, pant-type articles are typically so configured to accommodate size and configuration ranges by providing the elastic belt region very stretchable and comfortable to wear, yet with reliable fit such that sufficient protection against sagging and leakage may be provided. Further, the elastic belt region may be the portion which is most touched and observed by the wearer or the caregiver upon use, and thus its properties most associated with the quality of the article. By quality, what may be desired is an undergarment-like appearance provided by aesthetically pleasing regularity of gathers.
Based on the foregoing, there is a need for a wearable article providing improved stretchability for ease of application, improved fit for preventing sagging, improved comfort and softness, and improved sweat management and breathability for skin health. There is also a need for a wearable article having improved regularity of gathers which intuitively communicates the functional benefits described above. There is also a need for providing such a wearable article which can be economically made.
The present invention is directed to a wearable article continuous in a longitudinal direction and a transverse direction comprising a front elastic belt region, a back elastic belt region, a crotch region, a waist opening, and a pair of leg openings; the crotch region extending longitudinally between the front elastic belt region and the back elastic belt region; wherein at least 10%, preferably at least 15%, and not more than 70%, of the longitudinal dimension of the front and back elastic belts from the waist opening is a laminate in active elasticity defining an Upper Gather Region, the laminate comprising an inner sheet, an outer sheet, and a plurality of elastic strands running in the transverse direction and spaced apart with each other with a pitch of from at least about 6 mm to about 18 mm in the longitudinal direction, wherein the laminate further comprising an elastic bonding which continuously bonds the elastic member for at least about 10 mm in the direction of stretch in a region adjacent the side edges of the front and back elastic belts, and a vertical bonding applied to at least one of the inner sheet and the outer sheet with intervals in the transverse direction to intermittently bond the inner sheet and the outer sheet, wherein the inner sheet has an inner sheet hydrophilicity, the outer sheet has an outer sheet hydrophilicity, wherein the outer sheet hydrophilicity is greater than the inner sheet hydrophilicity; wherein the laminate has a Laminate Thickness of no greater than about 3.5 mm according to the measurement method herein.
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as forming the present invention, it is believed that the invention will be better understood from the following description which is taken in conjunction with the accompanying drawings and which like designations are used to designate substantially identical elements, and in which:
As used herein, the following terms shall have the meaning specified thereafter:
“Wearable article” refers to articles of wear which may be in the form of pants, taped diapers, incontinent briefs, feminine hygiene garments, and the like. The “wearable article” may be so configured to also absorb and contain various exudates such as urine, feces, and menses discharged from the body. The “wearable article” may serve as an outer cover adaptable to be joined with a separable disposable absorbent insert for providing absorbent and containment function, such as those disclosed in PCT publication WO 2011/087503A.
“Pant” refers to disposable absorbent articles having a pre-formed waist and leg openings. A pant may be donned by inserting a wearer's legs into the leg openings and sliding the pant into position about the wearer's lower torso. Pants are also commonly referred to as “closed diapers”, “prefastened diapers”, “pull-on diapers”, “training pants” and “diaper-pants”.
“Longitudinal” refers to a direction running substantially perpendicular from a waist edge to an opposing waist edge of the article and generally parallel to the maximum linear dimension of the article.
“Transverse” refers to a direction perpendicular to the longitudinal direction.
“Proximal” and “distal” refer respectively to the position closer or farther relative to the longitudinal center of the article.
“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).
“Disposed” refers to an element being located in a particular place or position.
“Joined” refers to configurations whereby an element is directly secured to another element by affixing the element directly to the other element and to 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.
“Film” refers to a sheet-like material wherein the length and width of the material far exceed the thickness of the material. Typically, films have a thickness of about 0.5 mm or less.
“Water-permeable” and “water-impermeable” refer to the penetrability of materials in the context of the intended usage of disposable absorbent articles. Specifically, the term “water-permeable” refers to a layer or a layered structure having pores, openings, and/or interconnected void spaces that permit liquid water, urine, or synthetic urine to pass through its thickness in the absence of a forcing pressure. Conversely, the term “water-impermeable” refers to a layer or a layered structure through the thickness of which liquid water, urine, or synthetic urine cannot pass in the absence of a forcing pressure (aside from natural forces such as gravity). A layer or a layered structure that is water-impermeable according to this definition may be permeable to water vapor, i.e., may be “vapor-permeable”.
“Extendibility” and “extensible” mean that the width or length of the component in a relaxed state can be extended or increased.
“Elasticated” and “elasticized” mean that a component comprises at least a portion made of elastic material.
“Elongatable material”, “extensible material”, or “stretchable material” are used interchangeably and refer to a material that, upon application of a biasing force, can stretch to an elongated length of at least about 110% of its relaxed, original length (i.e. can stretch to 10 percent more than its original length), without rupture or breakage, and upon release of the applied force, shows little recovery, less than about 20% of its elongation without complete rupture or breakage as measured by EDANA method 20.2-89. In the event such an elongatable material recovers at least 40% of its elongation upon release of the applied force, the elongatable material will be considered to be “elastic” or “elastomeric.” For example, an elastic material that has an initial length of 100 mm can extend at least to 150 mm, and upon removal of the force retracts to a length of at least 130 mm (i.e., exhibiting a 40% recovery). In the event the material recovers less than 40% of its elongation upon release of the applied force, the elongatable material will be considered to be “substantially non-elastic” or “substantially non-elastomeric”. For example, an elongatable material that has an initial length of 100 mm can extend at least to 150 mm, and upon removal of the force retracts to a length of at least 145 mm (i.e., exhibiting a 10% recovery).
“Dimension”, “Length”, “Width”, “Pitch”, “Diameter”, “Aspect Ratio”, “Angle”, and “Area” of the article are all measured in a state wherein the article is extended to the Full Stretch Circumference W1 according to the “Whole Article Force Measurement” herein, and utilizing a ruler or a loupe, unless specified otherwise.
“Artwork” refers to a visual presentation to the naked eye, which is provided by printing or otherwise, and having a color. Printing includes various methods and apparatus well known to those skilled in the art such as lithographic, screen printing, flexographic, and gravure ink jet printing techniques.
“Color” or “Colored” as referred to herein includes any primary color except color white, i.e., black, red, blue, violet, orange, yellow, green, and indigo as well as any declination thereof or mixture thereof. The color white is defined as those colors having a L* value of at least 94, an a* value equal to 0±2, and a b* value equal to 0±2 according to the CIE L* a* b* color system.
The wearable article 20 may be a belt-type pant as in
The central chassis 38 may comprise a topsheet, a backsheet and an absorbent core 62 disposed between the topsheet and the backsheet, and further an outer cover layer 42 for covering the garment-facing side of the backsheet. The topsheet may be a water permeable substrate. The backsheet may be a water impermeable film. The outer cover layer 42 may be a nonwoven sheet. The central chassis 38 may contain an absorbent core 62 for absorbing and containing body exudates disposed on the central chassis 38, and an absorbent material non-existing region 61 surrounding the periphery of the absorbent core 62. The absorbent material non-existing region 61 may be made of the topsheet and/or the backsheet and/or the outer cover layer 42 and/or other parts configuring the central chassis 38. In the embodiment shown in
The absorbent core 62 may include an absorbent layer and an acquisition layer. The absorbent layer is the region wherein absorbent materials having a high retention capacity, such as superabsorbent polymers, are present. The absorbent layer may be substantially cellulose free. Superabsorbent polymers of the absorbent layer may be disposed between first and second layers of material immobilized by a fibrous layer of thermoplastic adhesive material. The first and second layers of materials may be nonwoven fibrous webs including synthetic fibers, such as mono-constituent fibers of PE, PET and PP, multiconstituent fibers such as side by side, core/sheath or island in the sea type fibers. Such synthetic fibers may be formed via a spunbonding process or a meltblowing process. The acquisition layer facilitates the acquisition and the distribution of body exudates and may be placed between the topsheet and the absorbent layer. The acquisition layer may include cellulosic fibers.
The absorbent layers may be disposed in plurality in the absorbent core 62. Some portions of the absorbent layers may be configured to have substantially no absorbent material to form a channel or a plurality of channels. Channels may be useful for allowing the absorbent core 62 to bend upon swelling with fluids, such that the absorbent article conforms to the wearer's body after swelling and prevent sagging of the article. The channels may also be formed in the acquisition layer, and may be configured to at least partly match the channels of the absorbent layer in the thickness direction.
The elastic belt 40 of the article of the present invention acts to dynamically create fitment forces and to distribute the forces dynamically generated during wear. The front and back elastic belts 84, 86 may be joined with each other only at the side edges 89 to form side seams 32, a waist opening and two leg openings. Each leg opening may be provided with elasticity around the perimeter of the leg opening. The elasticity around the leg opening may be provided by the combination of elasticity from the front belt 84, the back belt 86, and the central chassis 38.
The longitudinal length of the backsheet and the outer cover layer 42 may be the same, or may be varied. For example, the outer cover layer 42 may have a shorter length compared to that of the backsheet, such that the outer cover layer 42 is devoid where the central chassis 38 overlaps the elastic belt 40. By such configuration, the elastic belt may have better breathability. Further, such configuration may provide cost saving. The transverse width of the backsheet and the outer cover layer 42 may be the same, or may be varied. For example, the backsheet may have a shorter transverse width compared to that of the outer cover layer 42. By such configuration, the longitudinal side edges 48 of the crotch panel 56, which make part of the leg openings, may have better breathability. Further, such configuration may provide cost saving.
The front elastic belt 84 and back elastic belt 86 are configured to impart elasticity to the belt 40. Referring to
The laminate forming the front and back elastic belts 84, 86 have a structure wherein the inner sheet 94 and outer sheet 92 follow the gather shape of each other, and thus have higher percentage of area facing each other to be in direct contact. The laminate of the present invention thus has a relatively low Laminate Thickness, according to measurements herein, of no greater than about 3.5 mm, or no greater than about 3.0 mm, or no greater than about 2.5 mm. Further, in the laminate of the present invention, the inner sheet 92 has an inner sheet hydrophilicity, the outer sheet 92 has an outer sheet hydrophilicity, wherein the outer sheet hydrophilicity is greater than the inner sheet hydrophilicity. The relationship of the outer sheet 92 having higher hydrophilicity than the inner sheet 94 comprises situations where the inner sheet 94 is hydrophobic and the outer sheet 92 is hydrophilic; the inner and outer sheets are both hydrophobic wherein the outer sheet 92 has higher hydrophilicity (the inner sheet has higher hydrophobicity); and the inner and outer sheets are both hydrophilic wherein the outer sheet 92 has higher hydrophilicity. The inner and outer sheets may have a difference in contact angle of at least about 10 degrees, or a difference in contact angle of at least about 15 degrees, or a difference in contact angle of at least about 20 degrees. Without being bound by theory, it is believed that, by having the elastic members intermittently bonded and having a Laminate Thickness of no greater than about 3.5 mm, this increases the percentage of the body facing surface of the inner sheet 94 in direct contact with the body of the wearer, and further providing the inner sheet 94 relatively more hydrophobic, the outer sheet 92 relatively more hydrophilic, effective liquid removal and transport to the outer sheet is facilitated. Hence, the laminate enables fast and reliable transport of liquid, such as sweat, away from the body of the wearer and through the laminate thickness to outside the article.
The elastic belt region 40 may be closely associated with the function and quality of the article. Having apertures on the elastic belt 40 enhances breathability. When such apertures are visible from the garment facing side, this may provide an intuitive signal to the wearer or caregiver of breathability and comfort. Thus, at least the outer sheet may be provided with a first repeating pattern of apertures. Materials for forming the elastic belt region 40, as well as positioning of the apertures, and visibility of the apertures, are carefully planned by the manufacturer for providing the desirables for the article. An undergarment kind of appearance and aesthetically pleasing regularity of apertures may be associated with high quality. Pleasant tactile sense such as flexibility and cushiony touch may also enhance perception of high quality. Stretchability for ease of application, fit for preventing sagging, comfort and softness, may also be associated with high function. Highly aesthetically pleasing apertures and gathers which intuitively communicate the functional benefits described above provide the favorable entire usage experience of the article by the user. The user may be the wearer or the caregiver.
At least the outer sheet 92 comprises a first repeating pattern of apertures. The first repeating pattern of apertures may have a longitudinal orientation. What is described by the longitudinal orientation is the longitudinally directed impression that the naked eye perceives when observing the repeating visual presentation of the first repeating pattern.
Without being bound by theory, by providing the first repeating pattern of apertures having a longitudinal orientation, the non-elastic region 221 appears coordinated with the Upper Gather Region 220 to enhance the directionality of the longitudinally continuous gathers of the Upper Gather Region 220, thus enhancing perception of high quality. The laminate having improved visibility and regularity of the first repeating pattern of apertures may be suitably provided by the methods below. Such method may also be advantageous in providing improved regularity of gathers which provide various functional benefits, and which are also aesthetically pleasing. The gathers of the present invention are continuous in the longitudinal direction, however, the direction of continuity may or may not completely match the longitudinal axis. The direction of gather is the direction in which the individual gathers are continuous, wherein the individual gathers are lined up with mountains and valleys repeating in the transverse direction.
Referring to
What is meant by elastic bonding 230 herein is a bonding that bonds the elastic member 96 along the side edges 89 of the front and back elastic belts 84, 86. The elastic bonding 230 may be continuously applied to each elastic member 96 for a length of at least about 10 mm, or from about 10 mm to about 60 mm in the direction of stretch adjacent the side edges 89 of the front and back elastic belts 84, 86, including the length planned for side seaming. The elastic bonding 230 is to provide relatively strong bonding for the elastic member 96 and thus securely anchor the elastic member 96 within the laminate. The anchoring may be assisted by the side seaming A certain percentage, or a greater percentage, of the dimension of the elastic bonding 230 along the side edges 89 may be seamed. The elastic bonding may also be utilized for an effective process of deactivating a limited transverse dimension of the elastic member 96. Referring to
What is meant by vertical bonding 234 herein is a bonding applied to at least one of the inner sheet 94 and the outer sheet 92 with intervals in the transverse direction for intermittently bonding the inner sheet 94 and the outer sheet 92. The vertical bonding 234 may also bond the elastic member 96 to at least one of the inner sheet 94 and the outer sheet 92. The vertical bonding 234 may only be provided to the outer sheet 92. The vertical bonding 234 may only be provided to the inner sheet 94. Referring to
Referring to
Without being bound by theory, it is believed that by having less restriction for the inner sheet 94 and outer sheet 92 against the elastic members 96, this contributes in creating gathers of improved regularity, in that a significant amount of the inner and outer sheet materials 92, 94 existing between the discrete patterned adhesive bondings 234 are available for creating gathers continuous in the longitudinal direction. Without being bound by theory, it is also believed that, by having less restriction for the inner and outer sheet materials 92, 94 against the elastic members 96, this allows improved stretchability of the elastic members 96, which may provide ease of application. Compared to elastic belts made only by elastic adhesive bonding 230 wherein all of the elastic members 96 are continuously bonded, the elastic belt 40 of the present invention may have a lower Stretch Circumference Force, according to the measurements herein. What is meant by Stretch Circumference Force is the loading force at a certain stretch level, which is believed to simulate initial stretch experience felt by the wearer or caregiver when inserting hands and stretch opening the article. Further, despite such relatively low Stretch Circumference Force, the elastic belt 40 of the present invention may maintain a suitable Fit Circumference Force, according to the measurements herein. What is meant by Fit Circumference Force is the unloading force at a certain stretch level, which is believed to simulate the force felt by the wearer while wearing the article. Without being bound by theory, it is also believed that, by having less restriction for the inner and outer sheet materials 92, 94 against the elastic members 96, this improves the breathability of the overall laminate, which may enhance skin health. Without being bound by theory, it is also believed that discrete patterned adhesive bonding 234 provides a configuration wherein a greater percentage of the inner and outer sheet materials 92, 94 are available for forming the outer surfaces of the laminate when the elastic belt 40 is contracted, while the elastic members 96 remain positioned inside the thickness of the laminate. As such, the laminate is provided with improved loft and thickness, thus imparting improved comfort and softness when worn. Further, without being bound by theory, in that there is a great percentage of the inner and outer sheet materials 92, 94 available for forming the outer surfaces of the laminate in high regularity when the elastic belt 40 is contracted, this provides the body facing surface of the elastic belt 40 to have higher stiffness in the longitudinal direction, thus contributing in improved fit for preventing sagging. Still further, in that the elastic members are less visible when the elastic belt 40 is contracted, this further enhances the aesthetically pleasing regularity of gathers.
In order to make available for gathering a significant amount of the inner and outer sheet materials 92, 94 between the vertical bondings 234 in the transverse direction, VG1 may be from about 2 times to about 20 times, or from about 3.5 times to about 10 times of VG2.
By bonding, what may be utilized are any methods known in the art, such as use of hot melt adhesive, thermal energy, and ultrasonic energy. Bonding strength may be adjusted by the area of bonding, or by different adhesion or energy level provided by the bonding, for example, adjusting the amount and strength of an adhesive agent. The bonding strength of the elastic bonding 230 and the vertical bonding 234 may be the same or may be varied. The elastic bonding 230 and the vertical bonding 234 may be provided by the same hot melt adhesive.
The vertical bonding 234 may be a continuous line extending in the longitudinal direction. Referring to
The article of the present invention may have a Belt Elastic Bonding Percentage of less than about 25%, or less than about 20%, or less than about 15%, according to the measurements herein. Namely, among all the elastic members 96 disposed on the front belt 84, less than about 25% of those elastic members are bonded to the laminate in active elasticity by a complete elastic bonding 230, 230T along the length of active elasticity of the individual elastic member. When all of the elastic members are completely bonded by elastic bonding 230, 230T, then the Belt Elastic Bonding Percentage is 100%. The article of the present invention has the majority of elastic members intermittently bonded to the laminate.
Referring to
Referring to
The front and back elastic belts 84, 86 may be made by running the continuous inner and outer sheet materials as well as the continuous elastic strands along the transverse axis of the article, and bonding them via the elastic bondings 230 and vertical bondings 234. During manufacture, the continuous inner and outer sheet materials and continuous elastic strands may be transferred in the machine direction, wherein the machine direction of manufacture matches the transverse axis TX of the article. In such manufacturing process, the vertical bondings 234 are provided continuous or discretely aligned in the cross machine direction and intermittently spaced apart by a pitch of VG1 in the machine direction of manufacture. The longitudinal pattern of vertical bondings 234 may match the cross machine direction of manufacture, namely the longitudinal axis LX of the article, or may be slightly titled for better control of the process, particularly when the vertical bonding 234 is provided by applying bonding on a rotating roller. The vertical bonding 234 may be tilted with an angle from the cross machine direction of manufacture, namely the longitudinal axis LX of the article, by from about 0.1 to about 30 degrees in either clock-wise or counterclock-wise direction, or from about 0.1 to about 15 degrees in either clock-wise or counterclock-wise direction.
Referring to
Referring to
The individual aperture may be in the shape of an oval, or polyhedron, while having an aspect ratio of no more than about 3, or no more than about 2.5. Referring to
Referring back to
The inner sheet 94 for making the front and back elastic belts may comprise a second repeating pattern of apertures. This may further enhance the breathability of the elastic belt 40. The second repeating pattern of apertures on the inner sheet 94 may be the same as the first repeating pattern of apertures on the outer sheet 92 and matched to provide breathability. The second repeating pattern of apertures on the inner sheet 94 may be different from the first repeating pattern of apertures on the outer sheet 92 in one or more of size, longitudinal pitch, or transverse pitch. Such difference in first and second repeating patterns may prevent the skin of the wearer from being visible from the garment-facing side through the apertures. Conversely, the inner sheet 94 may be a non-apertured sheet.
The tensile stress (N/m) of the entirety of the front and back elastic belts 84, 86, respectively, may be profiled in order to provide the functional benefits of the present invention, such as ease of stretch and application, while also maintaining certain force during wear to prevent the article from sagging after loading. When the elasticity of the front and back elastic belts 84, 86 are provided by a plurality of elastic members 96 running in the transverse direction, the tensile stress may be adjusted by one or more of the following methods; 1) elongation rate of the elastic member 96; 2) density (dtex) of the elastic member 96; 3) longitudinal pitch of multiple elastic members 96; and 4) effective length of elasticity of the elastic member 96 in the transverse direction. By elongation, “0% elongation” is meant the original length of the elastic member. When a portion of an elastic member 96 is removed of its elasticity, the remainder of the intact elastic member capable of imparting elasticity is defined as the “effective length of elasticity of an elastic member”.
Referring to
In the article of the present invention, the tensile stress of the front proximal tummy zone 106 may be provided higher than the tensile stress of any of the front waist zone 102, the front distal tummy zone 104, or the front leg zone 108. The tensile stress of the front proximal tummy zone 106 may be higher than the tensile stress of any other zone, either in the front or the back. The tensile stress of the back distal tummy zone 104 may be provided higher than any of the tensile stress of the back waist zone 102, the back proximal tummy zone 106, or the back leg zone 108. When comparing the 4 zones each of the front belt and the back belt, the tensile stress may be provided greatest in the order of: the front proximal tummy zone 106, followed by the back distal tummy zone 104. Without being bound by theory, such profiling of the tensile stress per zone is believed to provide the article of the present invention with a shaped elastic belt 40 that conforms well to a human body, particularly to a lower torso of a child of less than 36 months of age, and therefore provide good fit and comfort to the wearer, without compromise of sagging prevention or leakage prevention. Namely, the front proximal tummy zone 106 is subject to high tensile stress such that the article may be anchored against the wearer's trochanter, while leaving more area for the back proximal tummy zone 106 to accommodate the wearer's buttock. As long as the article is anchored securely at the trochanter, the Upper Gather Region 220 may be provided in relatively lower tensile stress. Without being bound by theory, it is believed that such relatively lower tensile stress contributes in providing the Upper Gather Region 220 with improved regularity of gathering, as well as soft fit.
For the belt-type pant, the longitudinal length LB of the back elastic belt 86 and the longitudinal length LF of the front elastic belt 84 may be provided the same, or the back elastic belt 86 may have a greater longitudinal length LB as in
Providing an inner sheet or outer sheet fold over 95, 93 is advantageous for avoiding the waist opening 88 ending in sharp edges of the front or back belt 84, 86. Further, any elastic bodies 96 in the front or back belt 84, 85 may be disposed at least about 2 mm away, or from about 5 mm to about 9 mm away from the waist opening, to avoid the waist opening to be sharp, and also to ensure that any elastic body is not accidentally exposed during manufacture or use. The inner sheet or outer sheet fold over 95, 93 may extend toward the proximal edge such that there is overlap between the central chassis 38 by at least about 10 mm, or by at least about 15 mm, to secure integrity between the front and or back belt 84, 86 and central chassis 38.
Referring to
Referring to
Referring to
Referring to
The outer sheet 92 of the present invention may be a nonwoven having a basis weight of from about 10 gsm to about 55 gsm, or from about 10 gsm to about 35 gsm, and may have a fiber diameter of from about 0.8 dpf to about 6 dpf. The fiber diameter is described in denier per filament (dpf) used in the industry, which is grams/9,000 meters of length of fiber. The outer sheet 92 nonwoven may be made by processes such as spunbond, spunlace, carded or air-laid; and may comprise fibers and/or filaments made of polypropylene (PP), polyethylene (PE), polyethylene phthalate (PET), polylactic acid/polylactide (PLA) or conjugate fibers (such as PE/PET, PE/PP, PE/PLA) as well as natural fibers such as cotton or regenerated cellulosic fibers such as viscose or lyocell. The outer sheet 92 nonwoven may be a multilayer or composite structure combining nonwovens made by different processes and fibers such as combining spunbond and carded nonwovens. The outer sheet 92 nonwoven may be made by biodegradable material, or derived from renewable resources. Exemplary material for the outer sheet 92 include: air-through carded nonwoven having a thickness of at least about 50 μm, or at least about 80 μm, or at least about 200 μm. Such material may provide a soft lofty feeling to the garment-facing side. Suitable for the outer sheet 92 nonwoven of the present invention are air-through carded nonwoven material made of co-centric bicomponent fiber, crimping fiber made through core eccentric bicomponent filament or side by side bicomponent filament. Non-limiting examples of materials suitable for the outer sheet 92 nonwoven of the present invention include: 12-45 gsm air-through carded nonwoven substrate comprising PE/PET bi-component fibers, such as those available from Beijing Dayuan Nonwoven Fabric Co. Ltd. or Xiamen Yanjan New Material Co. Ltd., and 8-45 gsm spun melt nonwoven substrate comprising PP monofilament or PE/PP bi-component fibers, such as those available from Fibertex or Fitesa.
The inner sheet 94 of the present invention may be a nonwoven having a basis weight of from about 5 gsm to about 45 gsm, or from about 5 gsm to about 35 gsm. The inner sheet 94 nonwoven may have a fiber diameter of from about 0.5 dpf to about 4 dpf. The inner sheet 94 nonwoven may be made by processes such as spunbond, spunlace, carded or air-laid; and may comprise fibers and/or filaments made of polypropylene (PP), polyethylene (PE), polyethylene phthalate (PET), polylactic acid/polylactide (PLA) or conjugate fibers (such as PE/PET, PE/PP, PE/PLA) as well as natural fibers such as cotton or regenerated cellulosic fibers such as viscose or lyocell. The inner sheet 94 nonwoven may also be a multilayer or composite structure combining nonwovens made by different processes and fibers such as combining spunbond and carded nonwovens. The inner sheet 94 nonwoven may be made by biodegradable material, or derived from renewable resources. Non-limiting examples of materials suitable for the inner sheet 94 nonwoven of the present invention include: 12-30 gsm air-through carded nonwoven substrate made of PE/PET bi-component staple fiber, such as those available from Beijing Dayuan Nonwoven Fabric Co. Ltd. or Xiamen Yanjan New Material Co. Ltd., and 8-30 gsm spun melt nonwoven substrate comprising PP monofilament or PE/PP bi-component fibers, such as those available from Fibertex or Fitesa.
The basis weight of the outer sheet 92 and the inner sheet 94 may be adjusted such that the basis weight of the inner sheet 94 is not greater than the basis weight of the outer sheet 92. Thus, the outer sheet 92 may be provided with a soft lofty tactile sense which connotes high quality, while the inner sheet 94 may be kept thinner and conforming to the outer sheet 92, thus saving cost. Further, without being bound by theory, by providing the basis weight relationship as such, it is believed that skin sweating is effectively transported to the outer sheet 92 and outside the laminate, while preventing the transported sweat back to the inner sheet 94. The hydrophilicity/hydrophobicity of the outer sheet 92 and the inner sheet 94 is adjusted such that the hydrophilicity of the outer sheet 92 is higher than that of the inner sheet 94. Without being bound by theory, it is believed that such gradient of hydrophilicity is advantageous in transporting skin sweat from the inner sheet 94 to the outer sheet 92 and outside the laminate. The inner sheet 94 nonwoven may be inherently hydrophobic. The inner sheet 94 nonwoven may be provided hydrophobicity by treating with hydrophobic melt additives into polymer resin in the fiber making process, or by applying hydrophobic additives after the nonwoven is formed. The outer sheet 92 nonwoven may inherently be hydrophobic, and thus provided relatively more hydrophilic than the inner sheet 94 by treating with hydrophilic melt additives into polymer resin in the fiber making process, or by applying hydrophilic additive after the nonwoven is formed.
As described above, the outer sheet 92 may be provided with apertures. Apertures may be made by female-male hot pin process, hole punching process, hydroentanglement process using water jets and a screen to create holes, and combinations thereof. The apertures may be made by creating a plurality of weakened locations by heat, pressure, or ultrasonic energy, followed by incrementally stretching, causing said nonwoven web to rupture at the weakened locations such as described in U.S. Pat. No. 5,628,097. Such rupturing method may be particularly useful for nonwovens using spunbonded fibers and meltblown fibers. The apertures may be three-dimensional, nonhomogenous, unaligned and forming a pattern as described in PCT Publication WO 2016/73712. The inner sheet 94 may also be provided with apertures for breathability. Apertures for the inner sheet 94 may be made in the same or different process, size, and density as the outer sheet 92. Providing apertures may alter the stiffness of the inner or outer sheet 92, 94. The stiffness of the outer sheet 92 in the longitudinal direction and the transverse direction may be adjusted to provide the desired longitudinally continuing gathers.
The outer sheet may have a plurality of openings at an Opening Rate of from about 5% to about 50%, or from about 5% to about 40%, or from about 5% to about 30%, or from about 6% to about 8%, or from about 7% to about 15%, or from about 9% to about 25%, and an Effective Opening Area of from about 0.1 mm2 to about 25 mm2, or from about 0.1 mm2 to about 10 mm2, or from about 0.4 mm2 to about 2.0 mm2, or from about 0.5 mm2 to about 4 mm2, of from about 1.0 mm2 to about 5 mm2, or from about 4.0 mm2 to about 8 mm2, or from about 7 mm2 to about 15 mm2, according to the measurements herein.
Alternatively, or in addition, the inner sheet may haves a plurality of openings at an Opening Rate of from about 5% to about 50%, or from about 5% to about 40%, or from about 5% to about 30%, or from about 6% to about 8%, or from about 7% to about 15%, or from about 9% to about 25%, and an Effective Opening Area of from about 0.1 mm2 to about 25 mm2, or from about 0.1 mm2 to about 10 mm2, or from about 0.4 mm2 to about 2.0 mm2, or from about 0.5 mm2 to about 4 mm2, of from about 1.0 mm2 to about 5 mm2, or from about 4.0 mm2 to about 8 mm2, or from about 7 mm2 to about 15 mm2, according to the measurements herein.
The outer sheet may have a plurality of openings at an Opening Rate of from about 5% to about 50% according to the measurements herein. By further provide a certain opening area for the outer sheet, there is provided multiple moisture transport channels are provided which can contribute to an effective liquid removal and transport to the outer sheet. The transport channels may be driven by capillary force gradient, and enhanced exposure to outside the laminate away from the skin. Further, the relationship of the inner sheet and the outer sheet with regards thickness and basis weight may further play a role in effective liquid removal and transport. Optionally providing the outer sheet with a plurality of openings at an Opening Rate of from about 5% to about 50% may contribute in providing the thickness gradient.
Also, to provide a thickness gradient, the basis weight of the inner sheet may be not greater than the basis weight of the outer sheet.
The garment-facing side of the crotch region 30 of the present article may be provided with a third repeating pattern of apertures. The third repeating pattern of apertures may also have a longitudinal orientation. The third repeating pattern of apertures may have a common element as that of the first repeating pattern of apertures. By coordinating the visible apertures in the crotch region 30 and the front and/or back elastic belt 84, 86, the integral undergarment like appearance of the article may be enhanced. Further, for the belt-type pant, coordination of the visible apertures in the crotch region 30 and the front and/or back elastic belt 84, 86 may help alleviate the visibility of the border between the different parts.
Force is measured using an Electronic Tensile Tester with a computer interface such as the MTS Criterion C42 running TestWorks 4 Software (available from MTS SYSTEMS (CHINA) CO., LTD) or equivalent instrument. A load cell is selected so that force results for the samples tested will be between 10 and 90% of capacity of the load cell used. The instrument is calibrated according to the manufacturer's instructions. All testing is performed in a room maintained at 23±2° C. and 50±5% relative humidity.
The tensile tester is fitted with hanger-type sample holding fixtures 300 as shown in
Gauge Circumference=2×(H+D+πD/2)
where H is the vertical gap between the horizontal bar sections 302, and D is the outer diameter of the bar.
The instrument is set up to go through the following steps:
An article 20 sample is inserted onto the upper horizontal bar section 302 so that the bar passes through the waist opening and one leg opening of the article. The crosshead is raised until the specimen hangs above the lower bar and does not touch lower bar 302. The load cell is tared and the crosshead is lowered to enable the lower bar 302 to be inserted through the waist opening and other leg opening without stretching the article. The article is adjusted so that the longitudinal centerline LX of the article is in a horizontal plane halfway between the upper and lower bars 302. The center of the side portion in contact with the bar 302 is situated on the same vertical axis as the instrument load cell. The crosshead is raised slowly while the article is held in place by hand as necessary until the force is between 0.05 and 0.1N, while taking care not to add any unnecessary force. The gauge circumference at this point is the Initial Gauge Circumference. The test is initiated and the crosshead moves up at 254 mm/min until a force of 19.6N is attained, then the crosshead immediately returns to the Initial Gauge Circumference at the same speed. The maximum circumference at 19.6N and the force at 70% of the maximum circumference during the loading segment and unloading segment of the test are recorded.
The maximum circumference (mm) at 19.6N is defined as the Full Stretch Circumference W1. The Full Stretch Circumference (mm)×0.7 is defined as the 70% Stretch Circumference W2. The force (N) during the loading segment of the test at 70% Stretch Circumference is defined as the Stretch Circumference Force. The force (N) during the unloading segment of the test at 70% Stretch Circumference is defined as the Fit Circumference Force. Five samples are analyzed and their average are calculated and reported to the nearest 1 mm or 0.01N, respectively.
A wearable article 20 is cut open by scissors along both side seams, the front belt 84 is identified, and then a specimen is excised. The specimen is a strip having side seams 32, the upper end edge matching the waist opening, and the lower end edge extending parallel to the waist opening at a longitudinal distance of at least 10 mm from the waist opening and about 3 mm from the nearest existing elastic strand towards the crotch. A point 100 mm distant in the lateral direction from just laterally inside one of the side edges is marked. The thus marked 100 mm point is the first side edge, and just inside the side edge from which the 100 mm was counted is the second side edge.
The portion of the specimen 100 mm wide is stretched until the first and second side edges reach a distance of 200 mm, i.e. 100% elongation from the original width. Referring to
The thickness measurements of laminate specimens are performed on the cross-section images generated under uniform surface lighting condition, using an optical microscope such as Keyence 3D Measurement System VR-3200 or equivalent. The magnification and focus is adjusted such that the cross-section side of the specimen is suitably enlarged for measurement. The cross-section side of the specimen is also oriented such that it is substantially aligned to the horizontal direction.
Analyses are performed using ImageJ software (version 1.49v or above, National Institutes of Health, USA) and calibrated against a ruler certified by NIST or equivalent. The image needs to be distance calibrated with an image of the ruler to give an image resolution, i.e. 42 pixels per mm. The microscope acquires a specimen image with a field of view size of at least 100 mm along the cross-section side.
Open a specimen image in ImageJ. Set the scale according to the image resolution. Randomly select five gather positions along the cross-section side and measure the local thickness that is the vertical distance between the peak (P) i.e. highest point and the valley (V) i.e. lowest point of the cross-section for one gather position. The thickness (T) of specimen is the arithmetic mean of the five readings of local thickness and recorded to the nearest 0.1 mm
This measurement is for identifying the percentage of elastic members on a laminate which are attached to the laminate solely by elastic bonding, defined as “Belt Elastic Bonding Percentage”.
1. The test is performed in a room maintained at 23±2° C. and 50±5% relative humidity. The finished wearable article 20 sample is conditioned for more than 1 hour in the test room.
2. The front elastic belt 84 is to be examined with the side seam kept intact and attached to the front belt. Cut the back belt in the longitudinal direction about 20-50 mm away from both side seams by scissors to open the belt from the back side. The opened belt is then carefully removed from the central chassis by hand so as not to alter the active elasticity region of the laminate. Therefore, it is acceptable to leave a layer from the central chassis attached to the laminate sample if the laminate cannot be separated from the central chassis. Cold spray is not used.
3. Observe the laminate sample thus obtained to identify a non-elastic region obtained by tummy cut. There may be samples which do not have a non-elastic region, and for such laminate sample the remainder of this step is skipped, and there exists no “T sample” hereinafter. The portion of the laminate sample extending in the lateral direction that has a non-elastic region is considered a tummy cut region (T) and the remainder of the laminate sample is considered a waist region (W). Separate the waist region (W) and tummy cut region (T) by cutting in the transverse direction by scissors at the middle point of the elastic members closest to each region.
4. For both the W (waist region) sample and the T (tummy cut region) sample thus obtained, the inner edge of the side seams are marked by a ballpoint pen. For the T sample, there exist 2 active elasticity regions. The starting point of the active elasticity region adjacent the non-elastic region is identified by observing the belt gathers caused by active elastic shrinkage, and marked by a ballpoint pen. The total number of elastic members on each sample is counted (“Total Elastic”). Those elastic members which are curved (for example, those extending in the longitudinal direction around the leg opening which do not have direction of stretch in the transverse direction) or which overlap with each other are not counted.
5. Each W and T sample is gently stretched until the gathers of the active elasticity region just disappear, then the length of the elastic length of each elastic member is measured to the nearest 1 mm by a scale. For the W sample, the distance between one side of seam inner edge to the other side of seam inner edge is measured for each elastic and summed up (“Total Elastic Width”). For the T sample, the distance between one side of seam inner edge to the marked active elasticity starting points are measured for both active elasticity regions, and summed up (“Total Side Width”).
6. For both W and T samples, cut the sample approximately along the longitudinal center of each active elasticity region to remove the stretching force. There is one active elasticity region on the W sample, and two active elasticity regions on the T samples, thus this step generates 2 cut W samples and 4 cut T samples.
7. Stretch the cut samples approximately up to the Full Stretch Circumference W1 according to the “Whole Article Force Measurement” for 5 times by hand, enough to make the elastic members slip away from the laminate, however, not beyond the point where the stretching damages the sheet materials constructing the samples. It should be noted that there is a possibility that there may be no slipping of elastic members.
8. Mark each individual elastic at the point up to where active elastic remains after the slip by observing belt gathering by active elastic shrinkage.
9. The cut samples are again gently stretched until the gathers just disappear, and then the remaining active elastic length of each individual elastic member is measured to the nearest 1 mm by a scale and summed up (“Total Elastic Bonding Width”).
10. The number of elastics members which keep initial active elastic length without slip is counted (“Full bonded Elastic”). For the cut W sample, a particular elastic member is considered as “slipped” if one of the left or right side cut sample of the elastic member slips. For the cut T sample, a particular elastic member is considered as “slipped” if any of the elastic portions of the cut samples is slipped.
11. “Belt Elastic Bonding Percentage” (%) is the number of “Full bonded Elastic” divided by the number of “Total Elastic” reported to the nearest 1%.
When a nonwoven specimen is obtained from a finished product sample or laminate sample rather than obtained as a fresh material, the following procedures are taken.
A. To obtain a specimen, when available, an area free of deformation or wrinkling is selected. For the inner sheet 94 or outer sheet 92 of a wearable article, when available, area where the elasticity is deactivated is selected. The outer sheet and inner sheet are separated from the other components such as belt laminated nonwoven layers, or backsheet film by techniques such as applying “Quik-Freeze®” type cold spray, or other suitable methods that do not permanently alter the properties of the nonwoven composition. The technical face-side is the surface intended to be used as the garment-facing surface for the outer sheet, and the body-facing surface for the inner sheet. Care should be taken to prevent stretching of the nonwoven composition during the separation process. An 80 mm by 80 mm square shape is cut out using a cutter and a 64 cm2 die for obtaining the specimen.
B. Any remaining adhesive is removed from the specimen by the following steps using Tetrahydrofuran (THF) as solvent.
1) In a hood, transfer 1 liter of THF into the 3-4 liter beaker
2) Submerge specimen in the 1 liter of THF
3) Place beaker on shaking table and stir gently for 15 minutes and keep solution with sample sit for 5 additional minutes
4) Take specimen out of THF solution, and carefully squeeze THF solution out of specimen.
5) Let specimen air dry in hood for a minimum of 15 minutes
Specimen are obtained from five (5) finished articles or laminates and cut out from the same area of each article or laminate, for each set of measurement. Specimen are pre-conditioned in a room maintained at 23±2° C. and 50±5% relative humidity, for at least 2 hours prior to testing.
Effective Opening Area and Opening Rate measurements are obtained by analyzing images of either an outer sheet or an inner sheet specimen independently. Specimen images are generated using an optical microscope such as a Keyence 3D Measurement System VR-3200, or equivalent. Image analysis is performed using ImageJ software (version 1.49 or above, National Institutes of Health, USA, or equivalent). The specimen image needs to be distance calibrated with an image of a ruler to determine the image resolution, i.e. 42 pixels per mm. The layer specimen is backed with a black material prior to acquiring the image. A total of five replicate specimens are prepared for analysis.
Following the instrument manufacturer's recommended procedures, auto-focus the microscope and acquire a specimen image with a field of view size of 50 mm by 50 mm at a resolution of approximately 42.4 pixels per mm. In like fashion acquire images of the remaining four replicates.
Open a specimen image in ImageJ. Set the scale according to the resolution of the calibrated ruler image. Convert the image type to 8 bit. Using the minimum auto threshold, the 8-bit grayscale image is then converted to a binary image (with “zero” or “black” corresponding to the aperture regions) in the following way: If the histogram of gray level (GL) values (ranging from 0 to 255, one bin with propensity Pi per gray level i) has exactly two local maxima, the threshold gray level value t is defined as that value for which Pt−1>Pt and Pt≤Pt+1. If the histogram has greater than two local maxima, the histogram is iteratively smoothed using a windowed arithmetic mean of size 3, and this smoothing is performed iteratively until exactly two local maxima exist. The threshold gray level value t is defined as that value for which Pt−1>Pt and Pt≤Pt+1. This procedure identifies the gray level (GL) value for the minimum population located between the dark pixel peak of the aperture holes (openings) and the lighter pixel peak of the specimen material.
Remove outliers before measurement by setting the opening exclusion limit to 10 pixels in radius for dark outliers and 2 pixels in radius for bright outliers. Select the Analyze Particles function. Set the analysis to exclude the partial edge openings and calculate the average opening area via dividing the total area of all included openings by the number of openings, and record as the Effective Opening Area to the nearest 0.1 mm2. Add up all the opening area values from the image, including both full and partial openings, and divide the sum by the total area of the field of view of the image, and record as the Opening Rate (%) to the nearest 0.1%. In like fashion analyze the remaining 4 specimen images. Calculate and report the average Effective Opening Area to the nearest 0.1 mm2 and the average Opening Rate to the nearest 0.1% for the total 5 replicates.
Examples 1 and A-C were obtained as such, and subject to tests as described below.
Example 1 has the configuration, elastic profile, and other properties as in
(*1) “Tummy cut” in Table 1 refers to deactivation of elasticity at the transverse central area of elastic strands resulting in 68% effective length of elasticity.
Example A: Size 4 (L-size) uni-body type pant article sold by the tradename of “Merries” having Lot No. 20190422, purchased in the China market.
Example B: Size 4 (L-size) uni-body type pant article sold by the tradename of “GooN Super Premium—Feather” having Lot No. 20181004, purchased in the China market.
Example C: Size 4 (L-size) belt-type pant article sold by the tradename of “Teddy Bear More than thinner” having Lot No. 20190424D, purchased in the China market.
The Laminate Thickness and Belt Elastic Bonding Percentage of the Examples were measured according to the measurements herein, and results found in Table 2.
The article of Example 1 provides good sweat management properties, improved stretchability for ease of application, improved fit for preventing sagging, improved comfort and softness, and improved breathability for skin health. Example 1 also provides aesthetically pleasing regularity of gathers and good visibility of apertures in the Upper Gather Region (220).
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” Further, every numerical range given throughout this specification includes every narrower numerical range that falls within such broader numerical range.
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| PCT/CN2019/075101 | Feb 2019 | CN | national |
| PCT/CN2020/073515 | Jan 2020 | CN | national |
This application claims priority to Chinese PCT Patent Application No. PCT/CN2020/073515, filed on Jan. 21, 2020, and to Chinese PCT Patent Application No. PCT/CN2019/075101, filed on Feb. 14, 2019, both of which are incorporated by reference herein.
