Patent Application
20190274895
The present invention relates to a wearable article comprising an elastic laminate suitable for use in wearable articles which exhibits improved sweat management properties.
Substrate materials such as nonwoven fabrics and laminates thereof, are commonly used for wearable articles such as absorbent articles. For example, absorbent articles typically use nonwoven substrate materials for both the skin facing side as well as the garment facing side of the articles, to control the movement of liquids and to provide a comfortable, conforming fit when the article is worn by a wearer. By comfortableness, what may be desired is a cloth-like substrate which is capable of effectively absorbing sweat and excess moisture from the skin and releasing them outside the article. Such is particularly desired for absorbent articles by caregivers of young children, wherein skin health is closely associated with the absence of heat rashes and diaper rashes. Heat rashes in the waist area may be associated with wetness or dampness in the waist area inside an absorbent article. It is a common practice for caregivers to check the degree of wetness or dampness by touching the waist area inside the absorbent article worn by a young child.
Elastic laminates having sweat management properties have been proposed, such as those described in Japanese Patent Application publications 2017-12319A and 2017-113186A. There is a need to provide elastic laminates with further improved sweat management properties, while being economic to make.
The present invention is directed to a wearable article comprising an elastic laminate, the elastic laminate comprising
an inner first nonwoven layer and an outer second nonwoven layer, wherein the inner layer and the outer layer are directly joined with each other over an area of from about 5% to about 50%,
the inner layer being closer to the body of the wearer than the second layer when the article is worn, the inner layer having a first surface facing away from the outer layer and a second surface facing towards the outer layer,
the outer layer having a higher hydrophilicity than the inner layer and having a first surface facing towards the inner layer and a second surface facing away from the inner layer;
the laminate having a total caliper when subjected to the NMR MOUSE method as defined herein, the total caliper having a first sub-caliper corresponding to 50% of the total caliper, starting from the outer layer's second surface and extending towards the inner layer's first surface, and a second sub-caliper corresponding to the remaining 50% of the total caliper, starting from the inner layer's first surface and extending towards the outer layer's second surface, and
wherein the elastic laminate has a Liquid Ratio of the first sub-caliper to the second sub-caliper of at least 1.1, or at least 1.2, or at least 1.3, after 1 minute according to the NMR MOUSE method set out herein.
The elastic laminate may comprises an inner layer fold over region wherein the inner layer is elongated beyond the elastic laminate, and the elongated part of the inner layer is folded over itself, the folded over part of the inner layer thereby forming a third layer such that at least a portion of the elastic laminate comprises the inner, outer and third layer (the inner layer being sandwiched between the third layer and the outer layer). The third layer may be attached to the first surface of the inner layer, e.g. by adhesive such as intermittent adhesive bonding. The third layer facing towards the skin of the wearer in use may be treated to have higher hydrophobicity than the inner layer.
In addition, the elastic laminate may further comprise an outer layer fold over region wherein the outer layer is elongated beyond the elastic laminate and the elongated part of the outer layer is folded over the third layer, the folded over part of the outer layer thereby forming a fourth layer such that at least a portion of the elastic laminate comprises the inner layer and third layer sandwiched between outer layer and the fourth layer. The fourth layer may be attached to the third layer, e.g. by adhesive such as intermittent adhesive bonding. The third layer may extend beyond the fourth layer (i.e. cover a larger surface area than the fourth layer). The extension of the fourth layer may form less than 20%, or less than 10% of the surface area of the elastic laminate, determined when the elastic laminate is stretched such that the inner and outer layer are flattened out.
Alternatively, The elastic laminate may comprise only an outer layer fold over region (i.e. no inner layer fold over region), wherein the outer layer is elongated beyond the elastic laminate, and the elongated part of the outer layer is folded over the elastic laminate, the folded over part of the outer layer thereby forming a third layer such that at least a portion of the elastic laminate comprises the inner layer sandwiched between the outer layer and the third layer. The third layer may be attached to the first surface of the inner layer, e.g. by adhesive such as intermittent adhesive bonding. The third layer facing towards the body of the wearer in use may be treated to have equal or higher hydrophobicity than the inner layer.
Of course, in a still further alternative, the elastic laminate may not comprise any folded over extensions of the inner and outer layer at all.
At least 40%, or at least 50% of the first surface of the inner layer, and/or at least 50% of the third layer formed by folding over an extension of the inner layer may be in direct contact with the body of the wearer during use of the wearable article.
The elastic laminate may form an elastic belt of the wearable article, the elastic belt comprising a front belt and a rear belt. The first surface, or at least 50% of the first surface, of the inner layer may be in direct contact with the body of the wearer during use of the wearable article.
The elastic laminate defined above enables fast and reliable transport of liquid, such as sweat, away from the body of the wearer and through the elastic laminate to the outside.
Liquid transport away from the skin and through the laminate is measured by using NMR MOUSE (Nuclear Magnetic Resonance Mobile Universal Surface Explorer) methodology. NMR MOUSE is a portable device using an open NMR sensor to characterize fluid positioning inside a porous media structure (i.e. the elastic laminate). The method enables precise determination of liquid distribution at different points in time.
For the method, the inner layer of the elastic laminate is brought into contact with a solution of 0.9% sodium chloride (see detailed method description below) and a weight of 0.25 psi is applied onto the second surface of the outer layer to simulate normal in use conditions when a standing person wears the wearable article. A Liquid Ratio of the first sub-caliper to the second sub-caliper of at least 1.1 after 1 minute means that, already 1 minute after the elastic laminate has been brought into contact with the liquid solution, more than 50% of the liquid within the elastic laminate has already been distributed to the first sub-caliper of the elastic laminate which is facing away from the body of the wearer.
Having an elastic laminate comprising an inner and an outer layer, it is essential that liquid moves quickly from the inner layer to and through the outer layer to enable efficient sweat management. Elastic laminates having a Liquid Ratio of the first sub-caliper to the second sub-caliper of at least 1.1, or at least 1.2, or at least 1.3 after 1 minute according to the NMR MOUSE method provide good sweat management, thus contributing to improved skin health.
The elastic laminate may have a Liquid Ratio of the first sub-caliper to the second sub-caliper of at least 1.5, or at least 1.8 after 10 minutes, and of at least 2.0 after 20 minutes according to the NMR MOUSE method provide good sweat management, thus contributing to improved skin health.
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, wound dressings, hospital garments, and the like. The wearable article of the present invention may be a pant. 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.
As used herein, “taped diaper” and “pant” refers to an absorbent article generally worn by babies, infants and incontinent persons about the lower torso to encircle the waist and legs of the wearer and that is specifically adapted to receive and contain urinary and fecal waste. In a pant, as used herein, the longitudinal edges of the first and second waist region are attached to each other to a pre-formed waist opening and leg openings. A pant is generally placed in position on the wearer by inserting the wearer's legs into the leg openings and sliding the pant absorbent article into position about the wearer's lower torso. A pant may be pre-formed by any suitable technique including, but not limited to, joining together portions of the absorbent article using refastenable and/or non-refastenable bonds (i.e. with permanent side seams not intended to be torn upon prior to removal of the pant from the wearer for disposal). In a diaper, the waist opening and leg openings are only formed when the diaper is applied onto a wearer by (releasable) attaching the longitudinal edges of the first and second waist region to each other on both sides by a suitable fastening system.
“Taped diaper” refers to disposable absorbent articles which are applied on a wearer by tapes.
As used herein, “disposable” is used in its ordinary sense to mean an article that is disposed or discarded after a limited number of usage over varying lengths of time, for example, less than 20 usages, less than 10 usages, less than 5 usages, or less than 2 usages. If the disposable absorbent article is a taped diaper, a pant, sanitary napkin, sanitary pad or wet wipe for personal hygiene use, the disposable absorbent article is most often intended to be disposed after single use. The absorbent articles described herein are disposable.
“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.
“Inner” and “outer” refer respectively to the relative location of an element or a surface of an element or group of elements. “Inner” implies the element or surface is nearer to the body of the wearer during wear than some other element or surface. “Outer” implies the element or surface is more remote from the body of the wearer during wear than some other element or surface (i.e., element or surface is more proximate to the wearer's garments that may be worn over the present 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 another element of the same component. An example is the inner layer of the elastic laminate of the present invention wherein the inner layer (being an element of the elastic laminate) is nearer to the body of the wearer than the outer layer (being another element of the elastic laminate). “Garment-facing” implies the element or surface is more remote from the wearer during wear than another element of the same component. The garment-facing surface may face another (i.e. other than the wearable article) garment of the wearer, other items, such as the bedding, or the atmosphere.
“Proximal” refers to a portion being closer relative to the longitudinal center of the article, while “distal” refers to a portion being farther from the longitudinal center of the article.
“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.
A “nonwoven layer” is a nonwoven material which is a manufactured web of directionally or randomly oriented fibers, consolidated and bonded together, e.g. by one or more patterns of bonds and bond impressions created through localized compression and/or application of heat or ultrasonic energy, or a combination thereof. The term “nonwoven” does not include fabrics which are woven, knitted, or stitch-bonded with yarns or filaments. The fibers may be of natural or man-made origin and may be staple or continuous filaments. Nonwoven layers can be formed by many processes such as meltblowing, spunbonding, solvent spinning, electrospinning, and carding. Often, a nonwoven layer consists of sub-layers, which may be spunbond or meltblown, such as SMS, SMMS or the like. An SMS nonwoven layer consists of inner and outer spunbond sub-layers with a meltblown layer in between. In such nonwoven layer, the sub-layers are laid down on top of each other and the nonwoven layer is subsequently consolidated e.g. by thermal point (combination of heat and pressure in dedicated bond points) bonding to form a coherent nonwoven layer. The steps of laying down the sub-fibers and nonwoven layer consolidation are often carried out on one continuous manufacturing line. The basis weight of nonwoven fabrics is usually expressed in grams per square meter (g/m2). A nonwoven layer may be consolidated and bonded by hydroentanglement and/or needle punching, in addition to being consolidated and bonded by bonds obtained by heat and/or compression (including ultrasonic bonding). Carded nonwoven layers are formed of short, so-called staple fibers. They are typically formed into a layer of fibers and subsequently consolidated into a nonwoven layer, for example by autogenously bonding the fibers together with heat and/or by intertwining the fibers by known processes such as hydroentangling or needle-punching. The carded fibers may also be bonded together, e.g. by one or more patterns of bonds and bond impressions created through localized compression and/or application of heat or ultrasonic energy, or a combination thereof.
“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”.
“Hydrophilic” describes surfaces of substrates which are wettable by aqueous fluids (e.g., aqueous body fluids) deposited on these substrates. Hydrophilicity and wettability are typically defined in terms of contact angle and the strike-through time of the fluids, for example through a nonwoven fabric. This is discussed in detail in the American Chemical Society publication entitled “Contact Angle, Wettability and Adhesion”, edited by Robert F. Gould (Copyright 1964). A surface of a substrate is said to be wetted by a fluid (i.e., hydrophilic) when either the contact angle between the fluid and the surface is less than 90°, or when the fluid tends to spread spontaneously across the surface of the substrate, both conditions are normally co-existing. Conversely, a substrate is considered to be “hydrophobic” if the contact angle is greater than 90° and the fluid does not spread spontaneously across the surface of the fiber.
“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.
“Elongation rate” means the state of elongation of a material from its relaxed, original length, namely an elongation rate of 10% means an elongation resulting in 110% of its relaxed, original length.
“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 elongation rate of at least 10% (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 “elastic.” For example, an elastic material that has an initial length of 100mm 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-elastic”. 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).
Elastic Laminate of the Wearable Article:
The elastic laminate of the present invention comprises an inner layer being a nonwoven and an outer layer being nonwoven having higher hydrophilicity than the inner layer. The inner layer has a first surface facing away from the outer layer, and a second surface facing towards the outer layer. Hence, the first surface of the inner layer faces towards the skin of the wearer when the article is in use. The outer layer has a first surface facing towards the inner layer, and second surface facing away from the inner layer. Hence, the second surface of the outer layer faces towards the garment (overlaying the wearable article) of the wearer when the article is in use.
The inner and outer layer are directly joined with each other over an area of from about 5% to about 50%. By “directly joined” what is meant is that the inner layer and the outer layer are directly secured to each other by applying adhesive agents, ultrasound, pressure, heat, or the combination thereof. The percentage of area of the inner and outer layers that are directly joined with each other may vary depending on the joining method for forming the elastic laminate, as discussed in further detail below. The inner and outer layers are directly joined with each other over an area of from about 5% to about 50% to provide the sweat management property, while also maintaining integrity as an elastic laminate. The relationship of the outer layer having higher hydrophilicity than the inner layer comprises situations where the inner layer is hydrophobic and the outer layer is hydrophilic; the inner and outer layers are both hydrophobic wherein the outer layer has higher hydrophilicity (the inner layer has higher hydrophobicity); and the inner and outer layers are both hydrophilic wherein the outer layer has higher hydrophilicity. The inner and outer layers may have a difference in contact angle of at least about 10 degrees, or a difference in contact angle of at least 15 degrees, or a difference in contact angle of at least 20 degrees. Without being bound by theory, it is believed that, by providing the inner layer relatively more hydrophobic, the outer layer relatively more hydrophilic, effective liquid removal and transport to the outer layer is facilitated.
The outer layer 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 layer, there is provided multiple moisture transport channels are provided which can contribute to an effective liquid removal and transport to the outer layer. 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 layer and the outer layer with regards: fiber diameter, porosity, void cell diameter, thickness, and basis weight; may further play a role in effective liquid removal and transport. Porosity may be measured directly, or may be evaluated indirectly by measuring the Mean Flow Pore Size based on capillary flow porometry as described in the test method below. The inner layer may have a Mean Flow Pore Size of from about 50 μm to about 250 μm, or from about 55 μm to about 120 μm, or from about 60 μm to about 170 μm, or from about 65 μm to about 220 μm, or from about 70 μm to about 240 μm. The outer layer may have a Mean Flow Pore Size of from about 100 μm to about 400 μm, or from about 105 μm to about 350 μm, or from about 110 μm to about 300 μm, or from about 115 μm to about 250 μm. Optionally providing the outer layer 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 layer may be not greater than the basis weight of the outer layer. The inner layer of the present invention is a nonwoven which may have a basis weight of from about 5 g/m2 to about 45 g/m2, or from about 5 g/m2 to about 35 g/m2. The inner layer nonwoven may have a fiber diameter of from about 0.5 dpf to about 4 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 inner layer 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 layer 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 layer nonwoven may be made by biodegradable material, or derived from renewable resources. Non-limiting examples of materials suitable for the inner layer 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 inner layer nonwoven may be inherently hydrophobic. The inner layer nonwoven may be provided hydrophobicity by treating with hydrophobic melt additives into polymer resin in the fiber making process, or applying hydrophobic additives after the nonwoven is formed.
Hydrophobic additives may be fatty acids originated from vegetable, animal, and/or synthetic sources. Fatty acids may range from C8-C30 fatty acid, or from C12-C22 fatty acid, or substantially saturated fatty acid. Hydrophobic additives may be fatty acid derivatives including fatty alcohols, fatty acid esters, and fatty acid amides. Suitable fatty alcohols include those derived from C12-C30 fatty acids. Suitable fatty acid esters include those fatty acid esters derived from a mixture of C12-C30 fatty acids and short chain monohydric alcohols, and may be a mixture of C12-C22 saturated fatty acids and short chain monohydric alcohols. The hydrophobic melt additive may comprise a mixture of mono, di, and/or tri-fatty acid esters. An example includes fatty acid ester with glycerol having at least one alkyl chain, at least two, or three chains to a glycerol, to form a mono, di, or triglyceride. Suitable triglycerides include glycerol thibehenate, glycerol tristearate, glycerol tripalmitate, and glycerol trimyristate, and mixtures thereof. Exemplary hydrophobic melt additives include glyceryl tristearate, such as those commercially available as Techmer PPM15000. Hydrophobic agents may be fatty acid amides including those derivatives from a mixture of C12-C28 fatty acids (saturated or unsaturated) and primary or secondary amines such as erucamide, oleamide and behanamide.
Exemplary hydrophobic additives which may be applied after the nonwoven is formed include surfactants and silicone-based finishes, natural oil or wax such as cotton seed oil, beeswax and shea butter.
The inner layer may optionally have a plurality of openings at an Opening Rate of from about 5% to about 30%, or from about 5% to about 15%, 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 layer of the present invention is a nonwoven which may have a basis weight of from about 10 g/m2 to about 45 g/m2, or from about 10 g/m2 to about 35 g/m2, and may be adjusted such that the basis weight of the inner layer is not greater than the basis weight of the outer layer. 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 layer and outside the laminate, while preventing the transported sweat back to the inner layer. The outer layer nonwoven may have a fiber diameter of from about 0.8 dpf to about 6 dpf. The outer layer 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 layer 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 outer layer nonwoven may be made by biodegradable material, or derived from renewable resources.
The outer layer nonwoven may inherently be hydrophobic, and thus provided relatively more hydrophilic than the inner layer by treating with hydrophilic melt additives into polymer resin in the fiber making process, or applying hydrophilic additive after the nonwoven is formed.
Hydrophilic additives may be polypropylene and polyethylene polymers such as those available from Techmer PM (Clinton, Tenn., US) sold under the trade name of Techmer PPM15560; TPM12713, PPM19913, PPM 19441, PPM19914, and PM19668. Hydrophilic additives may include, ionic surfactants, cationic surfactants, amphoteric surfactants or mixtures thereof. Exemplary hydrophilic additives include 100410 AF PE MB marketed by Ampacet, Irgasuf HL560 commercially available from Ciba Speciality Chemicals Inc., Hydrosorb 1001 commercially available from Goulston Technologies Inc., Cirrasol PP682 commercially available from Uniqema, Stantex S 6327 commercially available from Cognis, Silastol PST, Silastol PHP26 commercially available from Schill & Seilacher, Silwet L-7608 commercially available from Momentive Performance Materials, silicone surfactant with a polyethylene oxide chain and molecular weight above 700 g/mol by the name Polyvel S-1416 or VW 315 commercially available from Polyvel Inc.
Exemplary material for the outer layer 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. The thickness may be less than 2000 μm, or less than 1500 μm, or less than 1250 μm. Such material may provide a soft lofty feeling to the garment-facing layer. Suitable for the outer layer 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 layer nonwoven of the present invention include: 12 g/m2 to 45 g/m2 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 basis weight and material thickness of the inner and outer nonwoven layer herein is related to materials obtained from a finished product according to the “Preparation for Thickness and Basis Weight” below and measured by “Base caliper method—ASTM D 654 Standard Test Method for Thickness of Paper and Paper Board” with modification of the loading to 500 Pa, and by “Basis weight—ASTM D 756 Practice for Determination of Weight and Shape Changes of Plastics Under Accelerated Service Conditions”, respectively. Total caliper of the elastic laminate is determined in the NMR MOUSE test method set out below.
The outer layer 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 layer 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
For either the outer layer and/or the inner layer, the openings may be apertures, slits, or the like. If the inner and outer layer have openings, the openings of the inner layer may be congruent with the openings of the outer layer. Alternatively, if the inner and outer layer have openings, the openings of the inner layer may not be congruent with the openings of the outer layer. In a still further alternative, if the inner and outer layer have openings, some of the openings in the inner layer may be congruent with the openings in the outer layer, while the remaining openings in the inner layer may not be congruent with the openings of the outer layer.
The openings in the inner and/or outer layer may be apertures having an aspect ratio of less than about 5. The aspect ratio of an opening is determined as such. The greatest dimension of the opening is measured, wherein the direction of the greatest dimension defines the first axis. The line perpendicular to the first axis is defines the second axis. The dimension of the opening along the second axis is measured, and defined the cross dimension. The aspect ratio is the greatest dimension divided by the cross dimension.
The openings 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 openings may be made by creating a plurality of weakened locations by heat or pressure 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 openings may be three-dimensional, nonhomogeneous, unaligned and forming a pattern as described in PCT Publication WO 2016/73712.
In the present invention, the openings from the inner layer and the outer layer may be configured to completely match, or partially match, or not match at all. The inner layer or the outer layer may be devoid of openings (alternatively, both layers may be devoid of openings). Namely, the combination of the inner layer and the outer layer may provide a Relative Opening Rate of 100%, less than 100%, or less than about 50%, or less than about 15% according to the measurements herein. What is meant by Relative Opening Rate is the percentage of opening of the elastic laminate which matches the opening of the outer layer. When there is only opening in the outer layer, the Relative Opening Rate is 0%, while when the openings of the outer layer and the inner layer completely match, the Relative Opening Rate is 100%. In the present invention, the inner layer may optionally have openings, and when so, the pattern and density of the openings may be changed so as to completely or partially match with those of the outer layer. Without being bound by theory, in one embodiment, it is believed that, by having at least some portions of some of the openings of the outer layer closed by the inner layer, this provides a liquid permeability gradient from the inner layer to the outer layer, thus sweat is effectively wicked and moved to the outer layer. Without being bound by theory, in another embodiment, it is believed that, by having the openings of the outer layer and the inner layer completely match, this provides favorable breathability and appearance.
The inner layer and the outer layer are directly joined to each other over an area of from about 5% to about 50% by any means known in the art, such as by applying adhesive, ultrasound, pressure, or heat, for providing the elastic laminate of the present invention. The inner and outer layers may be at least partially directly joined by adhesive agent. When adhesive agent is used for joining the inner and outer layers, the area in which adhesive agent is applied between the inner and outer layers is considered as area in which the layers are directly joined. When using adhesive agent as a joining means, the adhesive agent may be applied intermittently, such as in spiral pattern. Alternatively or additionally, the adhesive agent may be applied by a slot coat pattern for sake of better process control, wherein the area in which adhesive agent is applied is from about 5% to about 50%, or from about 5% to about 40%, or from about 5% to about 30% of the laminate planar area. Alternatively or additionally, the inner and outer layers may be at least partially directly joined by means which directly join the fibers of the inner and outer layer nonwovens, such as by heat, pressure, or ultrasound.
The elastic laminate of the present invention may have an elongation rate of at least about 110% in at least one direction. Elasticity may be imparted by laminating an elastic body between the inner layer and the outer layer. The elastic body may be a plurality of elastic strands or elastic ribbons, or an elastic sheet. The layers and elastic bodies may be at least partially joined by means selected from the group consisting of adhesive agent, heat, pressure, ultrasound, and combinations thereof. Referring to
Elastic laminates obtained by any of the aforementioned joining methods need not be embossed, or mechanically activated, beyond the force needed to at least partially directly join the layers. Thus, the elastic laminate may be economically made. The directly joined area may be measured by stretching the elastic laminate to an uncontracted condition, suitably with a force of 25N, and observing the planar area where the inner and outer layers are directly joined.
The Wearable Article
The present invention relates to a wearable article comprising an elastic laminate. The elastic laminate may form at least a part of a wearable article that is in direct contact with the skin.
The elastic laminate comprises an inner nonwoven layer and an outer nonwoven layer. The inner nonwoven layer is closer to the wearer than the outer layer when the article is worn. The inner nonwoven layer may be in direct contact with the skin of the wearer when the article is worn. The outer nonwoven layer may form at least a part of the outer surface of the wearable article.
The elastic laminate may be used as a component selected from the group consisting of elastic belts, waistbands, side panels, leg cuffs, and outer covers, of the wearable article.
The present elastic laminate is particularly useful as an elastic belt. The wearable article may be a pant. An exemplary pant is described in PCT Publication WO 2006/17718A. The pant may comprise a central chassis 38 to cover the crotch region of the wearer when the article is worn, a front belt 84 and a back belt 86 (hereinafter may be referred to as “front and back belts”) comprising the elastic laminate of the present invention, the front and back belts 84, 86 forming a discrete ring-like elastic belt 40 (hereinafter may be referred to as “waist belt”) extending transversely defining the waist opening. The wearable article 20 may be a uni-body type pant wherein the central chassis 38 is continuous with the front and back belt 84, 86, wherein the leg openings are continuously formed (not shown). The belt-type pant may be advantageous in that the central chassis 38 has better breathability, thus providing better sweat management for the entire wearable article.
As exemplarily shown in
While not depicted, the wearable article of the present invention may be a taped diaper having a longitudinal axis, a transverse axis, a body facing surface, and a garment facing surface. The wearable article may have a central chassis comprising a front region, a back region, and a crotch region, each defined by a laterally extending line notionally divided along the longitudinal axis in 3 equal lengths. The front region and/or the back region may be provided with fastening members for fastening the article to configure the waist opening and leg openings. The waist opening may comprise a waistband. The fastening member may be made by a connecting part connecting to the central chassis, a stretchable side panel which is stretchable in the lateral direction, and an engaging part having engaging elements such as hooks. The front region and/or the back region may be provided with a landing zone for receiving the engaging elements of the fastening member. The landing zone may be loops engageable with the hooks. At least a portion of, or the entirety of, the waistband, side panels, or landing zones of the wearable article may be the elastic laminate of the present invention.
The ring-like elastic belt 40 of the pant of the present invention acts to dynamically create fitment forces and to distribute the forces dynamically generated during wear. The proximal edge 90 is located closer than the distal edge 88 relative to the crotch panel 56 of the central chassis 38. The front and back belts 84, 86 may be joined with each other only at the side edges 89 at the seams to form a wearable article having a waist opening and two leg openings. Each leg opening may be provided with elasticity around the perimeter of the leg opening. For the belt-type pant, the elasticity around the leg opening may be provided by the combination of elasticity from the front belt 84, the back belt 86, and any from the central chassis 38.
The front belt 84 and back belt 86 of the pant are configured to impart elasticity to the belt 40. The front belt 84 and the back belt 86 may each be formed by the present elastic laminate comprising a plurality of elastic bodies 96 running in the transverse direction, an inner sheet 94 formed by the inner layer, and an outer sheet 92 formed by the outer layer. Optionally an outer sheet fold over 93 which is an extension of the outer sheet material may be formed by folding the outer sheet material, and/or an inner sheet fold over 95 which is an extension of the inner sheet material may be formed by folding the inner sheet material. The outer sheet 92 may be made of the same nonwoven substrate of the present invention as the outer cover layer 42 to provide integral aesthetic and tactile senses for the article.
When the central chassis 38 contains an absorbent core, some or all of the areas of the front or back belt 84, 86 overlapping the absorbent core may be made devoid of elasticity. Referring to
Providing an inner or outer 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 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.
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The articles of the present invention provide improved sweat management properties, are easy to apply and comfortable to wear, while being economic to make.
Test Methods
The NMR-MOUSE (Mobile Universal Surface Explorer) is a portable open NMR sensor equipped with a permanent magnet geometry that generates a highly uniform gradient perpendicular to the scanner surface (shown in
An exemplary instrument is the Profile NMR-MOUSE model PM25 with High-Precision Lift available from Magritek Inc., San Diego, Calif. Requirements for the NMR-MOUSE are a 50 μm resolution in the z-direction, a measuring frequency of 13.5 MHz, a maximum measuring depth of 25 mm, a static gradient of 8 T/m, and a sensitive volume (x-y dimension) of 40 by 40 mm2. Before the instrument can be used, perform phasing adjustment, check resonance frequency and check external noise level as per the manufacturer's instruction. All measurements are conducted in a room controlled at 23° C.±1° C. and 50%±2% relative humidity.
The test solution is prepared: 0.9% w/v saline solution prepared as 9.0 g of NaCl diluted to 1 L deionized water. 2 mM/L of Diethylenetriaminepentaacetic acid gadolinium (III) dihydrogen salt (available from Sigma Aldrich) is added. After addition the solutions are stirred using a shaker at 160 rpm for one hour. Afterwards the solutions are checked to assure no visible undissolved crystals remain. The solution is prepared 10 hours prior to use. Products for testing are conditioned at 23° C.±1° C. and 50%±2% relative humidity for two hours prior to testing.
Identify the elastic laminate of the wearable article and cut an 80.0 mm by 80.0 mm specimen from the elastic laminate. Ensure that only elastic laminate is cut out to enable a flat specimen 1022 on the frame. If the elastic laminate is attached to other components of the wearable article and a specimen cannot be cut without separating the elastic laminate, the elastic laminate should be carefully separated by appropriate techniques from those other components, e.g. by applying “Quik-Freeze®” type cold spray, or other suitable methods that do not permanently alter the properties of the elastic laminate.
As illustrated in
When the specimen 1022 is mounted on the frame 1023, the first surface of the inner layer is facing towards the NMR MOUSE instrument. Ensure the 40 mm×40 mm opening area of the frame 1023, into which the top marker is inserted is covered by the specimen 1022.
Like the frame 1023, the sample holder 1020 has an opening 1028 of 40 mm×40 mm. The depth of the opening in the sample holder 1028 is 400 μm. The sample holder has a dimension of 80 mm×80 mm and a height of 1.4 mm (including the 400 μm depth). Place the sample holder 1020 in the middle of the NMR MOUSE (above rf coil 1012) on plane 1006 to ensure that the sensitive NMR volume is within the 40 mm×40 mm opening 1028 where the liquid will be applied. Place the frame 1023 centered on top of the sample holder 1020, such that the top marker and opening 1028 are congruent and place the top marker onto the specimen 1022, such that glass plate 1026 is in contact with specimen 1022, to apply 0.25 psi on 40 mm×40 mm. The top marker is used to define the dimension of the specimen by determining the surface of the sample holder 1020 and the specimen 1022 in the 40 mm×40 mm opening area 1028.
To measure the specimen first 1-D Dry Distribution Profiles with and without the specimen 1022 are collected. Ensure that the prepared specimen on the instrument is aligned over top the rf coil 1012. Program the NMR-MOUSE for a Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence consisting of a 90° x-pulse follow by a refocusing pulse of 180° y-pulse using the following conditions:
Rx Phase of the NMR signal is optimized during the phase adjustment as described by the vendor to maximize the real part of the NMR signal which is used for data processing. A value of 230° was applied for our experiments. However, the optimal value may differ depending on the NMR instrument used, and hence the Rx phase should be optimized as described by the vendor. Pulse length for a 90° pulse depends on measurement depth which here is 5 mm and was determined to be 5 μs based on the optimization procedure described by the vendor. If necessary, the depth can be adjusted using a spacer 1011 (see
Collect NMR Amplitude data (in arbitrary units, a.u.) versus depth (μm) as the high precision lift steps through the specimen's depth. A representative graph with the specimen is shown in
After the Dry Distribution Profile has been measured remove the top marker and the frame 1023 with the specimen 1022 attached thereto. Apply 400 μl of test solution (see above for preparation of test solution) in the opening 1028 of the sample holder 1020. Immediately afterwards place the frame 1023 with the specimen 1022 still attached thereto on top of the sample holder 1020 and insert the top marker into the frame such that glass plate 1026 is in contact with the specimen 1022, analogous to the procedure for taking the Dry Distribution Profile. Measure the NMR 1-D Wet Distribution Profile in the wet state of the specimen 1 minute after the specimen 1022 has been brought into contact with the test solution and the top marker has been added to the sample. This profile is used to calculate the Liquid Ratio of the first sub-caliper to the second sub-caliper value after one minute.
The NMR 1-D Wet Distribution Profile used to calculate Liquid Ratio of the first sub-caliper to the second sub-caliper after 10 minutes, and after 20 minutes is determined in the following way: The top marker is removed to allow the liquid to evaporate from the sample holder through the specimen for first 10 min. Evaporation step is carried out with no additional air ventilation, i.e. evaporation is not accelerated by air ventilation. The frame with the specimen remains on top of the sample holder during the complete evaporation time. After 10 min insert the top marker into the frame and place it again on top of the sample holder and —without further waiting— measure the NMR 1-D Wet Distribution Profile. This profile is used to calculate the Liquid Ratio of the first sub-caliper to the second sub-caliper value after ten minutes.
Repeat the procedure to allow another 10 min evaporation of liquid through the specimen 1022 (like for the first 10 minutes, this evaporation step is carried out with no additional air ventilation, i.e. evaporation is not accelerated by air ventilation), and re-assemble the top marker onto the sample holder, then measure the NMR 1-D Wet Distribution Profile in the wet state of the specimen 20 minutes. This profile is used to calculate the Liquid Ratio of the first sub-caliper to the second sub-caliper value after twenty minutes.
When taking off the top marker for the evaporation steps as described above, no further test solution is filled in to the opening 1028, i.e. test solution is only filled in once, after the Dry Distribution Profile has been taken.
The liquid ratio of the first sub-caliper to the second sub-caliper is calculated as described below.
Area calculation is made for any range of caliper of interest such as the total caliper in the specimen (i.e. the total caliper of the elastic laminate), the first sub-caliper of the specimen (i.e. the first sub-caliper of the elastic laminate), and the second sub-caliper of the specimen (i.e. the second sub-caliper of the elastic laminate):
Where x is the depth in μm and S is the NMR Signal, n is the number of the data points. Calculate the volume for the first sub-caliper and the second sub-caliper as can be seen below.
Calculate liquid ratio by dividing the volume in the first sub-caliper by the volume of the second sub-layer as can be seen below.
Where Volumefirst-sub-caliper is the volume in 50% of the caliper of the specimen (i.e. of the elastic laminate) and Volumesecond-sub-caliper is the volume in the remaining 50% of the caliper of the flattened specimen on the frame as shown in
Each measurement (Dry Distribution Profile, Wet Distribution Profile after 1 minute, Wet Distribution Profile after 10 minutes, and Wet Distribution Profile after 20 minutes) is taken on one specimen only. Corresponding to each Wet Distribution Profile measured, a Liquid Ratio is calculated and reported as a dimensionless ratio to the nearest hundredth.
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.
Effective Opening Area and Opening Rate measurements are obtained by analyzing images of either an outer layer or an inner layer specimen independently, or both overlaying each other. 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 1.46 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. 42.4 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.
Relative Opening Rate is the opening rate of the outer layer and the inner layer combined, compared to the opening rate of the outer layer. Before preparation of specimen, the relationship of openings from the outer layer and the inner layer as the elastic laminate are observed. If the inner layer has no openings, the Relative Opening Rate is determined as 0%. If the inner layer has openings and the openings from the outer layer and the inner layer appear to completely or substantially match, the specimen is arranged as A). If the inner layer has openings and the openings from the outer layer and the inner layer appear to partially match or not match, the specimen is arranged as B).
The overlayed specimen are measured in the same manner as specified under “2. Effective Opening Area and Opening Rate” to obtain the Opening Rate of the overlayed specimen.
The Relative Opening Rate is obtained as such. When there is a complete match between the inner layer and the outer layer, the Relative Opening Rate is 100%.
Relative Opening Rate (%)=Opening Rate of overlayed specimen/Opening Rate of outer layer×100
Fiber Diameter is obtained as such. Scanning Electron Microscope images are taken using Hitachi TM3000 Bench-top SEM running Hitachi 3D-viewer software, or equivalent instrument. The specimen is cut into 20 mm by 20 mm and submerged in liquid nitrogen and an edge is fractured with a razor blade (stainless steel coated, single edge industrial blades, 62-0165). Fractured specimen is adhered to SEM mounts using double-sided tape (e.g. copper, carbon). The specimen is sputter Au coated and are viewed in the SEM. The SEM images are acquired from top view, and x-section view. Fiber diameter and width measurements are made using the manual line tool in SEM operating software.
Porosity and 3-dimensional void cell spacing is obtained by image analysis by first acquiring the image using X-ray Micro-CT.
An 8 mm×8 mm punch is used to physically extract a representative region of specimen. The 8 mm diameter sample is then placed in a sample holder with an inner diameter of 10 mm. The sample holder is then placed in an X-ray scanner such as GE Phoenix v|tome|x m (GE Sensing & Inspection Technologies GmbH, Niels-Bohr-Str. 7, 31515 Wunstorf, Germany). The scanning parameters used are nano-tube; voltage: 40 kV; current: 400 μA; tube mode: 1; timing: 2000 ms; averaging: 2; skip frames: 1; number of images: 2000. The resulting data set is 2014×2014×2014 voxels (volume pixels) with attenuation values represented as 16 bit integers. Each voxel has a diameter of 5 microns. For each type of specimen, three replicates are performed.
The 16-bit data was converted to 8-bit using a scaling factor of 0.01. A cylinder sub volume within the specimen of 7 mm in diameter and height around 90% in specimen height was cropped out from the original dataset for further calculation. To make measurements of Porosity and 3-dimenional void cell size distribution, the following steps were performed:
Mean Flow Pore Size of nonwoven is characterized by the gas-liquid displacement method according to ASTM F316, using a capillary flow porometer such as Porolux™ 100 NW (Porometer N.V., Belgium). The porometry measurement follows the Young-Laplace equation, P=4*γ*cos (θ)/D, where D is the pore size diameter, P is the pressure measured, γ is the surface tension of the wetting liquid, and θ is the contact angle of the wetting liquid with the sample. The procedures are the following:
The following nonwoven layers 1 to 6 have been assembled into elastic laminates of Examples 1 to 7 and Comparative Examples 8 and 9:
Nonwoven 1: 15 gsm spun calendar-bonded material made of hydrophobic PP monofilament, having fiber denier of 2 dpf, supplied by Fibertex.
Nonwoven 2: 20 gsm air-through carded material made of PE/PET bicomponent fibers having fiber denier of 2 dpf, treated hydrophobically with tradename “R11”, supplied by Xiamen Yanjan New Material Co. Ltd.
Nonwoven 3: 20 gsm air-through carded material made of PE/PET bicomponent fibers having fiber denier of 2 dpf, treated hydrophobically and apertured with tradename “J201-200”, supplied by Xiamen Yanjan New Material Co. Ltd.
Nonwoven 4: 20 gsm air-through carded material made of PE/PET bicomponent fibers having fiber denier of 2 dpf, treated hydrophilically and apertured with tradename “DZ203-200”, supplied by Xiamen Yanjan New Material Co. Ltd.
Nonwoven 5: 20 gsm air-through carded material made of PE/PET bicomponent fibers having fiber denier of 2 dpf, treated hydrophilically with tradename “Z08”, supplied by Xiamen Yanjan New Material Co. Ltd.
Nonwoven 6: 13 gsm SMS material comprising spunbond and meltblown layers made of hydrophobic PP monofilament with tradename “SM13011”, supplied by First Quality Nonwovens, Inc.
Nonwovens 1 to 6 have been assembled into elastic laminate as follows:
Also, three elastic laminates have been made wherein the inner and/or outer layer were folded over:
Liquid Ratio after 1 minute and after 20 minutes has been determined for Examples 1 to 6, as well as for Comparative Example 8, see Table 3 (Examples 1 to 6) and Table 4 (Comparative Examples 8 and 9).
Moreover, Liquid Ratio after 1 minute and after 20 minutes has been determined for the elastic belt (being formed by an elastic laminate) for the commercially available disposable absorbent pants (Comparative Examples 1 to 7) according to Table 4:
For Examples 1 to 5, the following further parameters have been determined:
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.
This application is a continuation-in-part, under 35 USC 120, of Application No. Chinese Patent Application Serial No. PCT/CN2019/075104, filed Feb. 14, 2019 and a continuation, under 35 USC 120, of Chinese Patent Application Serial No. PCT/CN2018/078113, filed on Mar. 6, 2018, the entire disclosures of which are hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2018/078113 | Mar 2018 | US |
| Child | PCT/CN2019/075104 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2019/075104 | Feb 2019 | US |
| Child | 16291388 | US |
