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WO2019007512A1 - Article absorbant comprenant une structure absorbante monolithique comprenant un matériau formant un hydrogel - Google Patents

Article absorbant comprenant une structure absorbante monolithique comprenant un matériau formant un hydrogel Download PDF

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Publication number
WO2019007512A1
WO2019007512A1 PCT/EP2017/066939 EP2017066939W WO2019007512A1 WO 2019007512 A1 WO2019007512 A1 WO 2019007512A1 EP 2017066939 W EP2017066939 W EP 2017066939W WO 2019007512 A1 WO2019007512 A1 WO 2019007512A1
Authority
WO
WIPO (PCT)
Prior art keywords
absorbent
absorbent structure
monolithic
layer
liquid
Prior art date
Application number
PCT/EP2017/066939
Other languages
English (en)
Inventor
Philip BLOMSTRÖM
Peter Rönnberg
Kent Vartiainen
Axel Eriksson
Harald WUTZEL
Original Assignee
Essity Hygiene And Health Aktiebolag
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Essity Hygiene And Health Aktiebolag filed Critical Essity Hygiene And Health Aktiebolag
Priority to PCT/EP2017/066939 priority Critical patent/WO2019007512A1/fr
Publication of WO2019007512A1 publication Critical patent/WO2019007512A1/fr

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/15577—Apparatus or processes for manufacturing
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/45—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the shape
    • A61F13/47—Sanitary towels, incontinence pads or napkins
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/53—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/53—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium
    • A61F2013/530802—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium characterized by the foam or sponge other than superabsorbent
    • A61F2013/53081—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium characterized by the foam or sponge other than superabsorbent with special pore dimension or arrangement
    • A61F2013/530817—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium characterized by the foam or sponge other than superabsorbent with special pore dimension or arrangement being open cells

Definitions

  • Absorbent article comprising a monolithic absorbent structure comprising a hydrogel-forming material DESCRIPTION
  • the present invention relates to a hygiene absorbent article such as a diaper or sanitary napkin, comprising a monolithic absorbent structure comprising a hydrogel- forming material and a process for its manufacture using a photopolymerization step.
  • Absorbent layers for absorbing biofluids are widely used in hygiene absorbent products, such as diapers, incontinence guards (incontinence protection) and sanitary napkins.
  • these absorbent layers contain superabsorbent polymers (SAP) or other hydrogel-forming materials, which are crosslinked hydrophilic polymers capable of absorbing large amounts of biofluids.
  • SAP superabsorbent polymers
  • hydrogel-forming materials which are crosslinked hydrophilic polymers capable of absorbing large amounts of biofluids.
  • SAP particles used in absorbent layers are typically separated by mechanical means (pockets) or mixed with fibrous materials such as fluff in order to prevent so-called "gel blocking".
  • the absorbent composite has a stretchable substrate layer and a plurality of pockets in or on the substrate layer.
  • the pockets each contain a quantity of superabsorbent material, which can swell when exposed to a liquid insult. When the substrate is stretched, the pockets become spaced further apart, thereby promoting comfort and alleviating gel blocking caused by adjacent pockets swelling toward each other.
  • EP 1 060 722 A2 teaches to combine in the absorbent core polymeric gelling agents with 200-300 grams per square meter pulp.
  • an absorbent article such as diaper, pant diaper, panty liner, sanitary napkin or incontinence protection, the absorbent article comprising a liquid-pervious topsheet, a backsheet and an absorbent structure arranged between the liquid-pervious topsheet and the backsheet,
  • the absorbent layer comprises or consists of a monolithic absorbent structure made from a hydrogel-forming material
  • the absorbent structure comprises at its surface apertures
  • the method comprising the step of manufacturing the absorbent structure by photopolymerizing, layer by layer, a photopolymerizable composition (the latter step is referred to below also as "LBL photopolymerization").
  • LBL photopolymerization a photopolymerizable composition
  • the monolithic structure of the absorbent structure contributes to a good absorbent capacity of the absorbent layer. If the monolithic absorbent structure swells, the size of the apertures, respectively the diameter of the channels, is enlarged essentially to the same extent as is the size of the absorbent structure, and the relative proportions of the structure do not notably change during absorption. Consequently, the fluid to be absorbed is transported at all times equally well, since the subjacent parts of the structure can be reached at all times by the body liquid. Hence, gel blocking is reduced or prevented.
  • the present invention provides the possibility to vary the surface area per cubic material on a micro scale and allows controlling the absorption rate and absorption capacity with higher precision than had been possible to date.
  • the present invention also provides a method for an absorbent article obtainable by the method defined in the claims and the present description.
  • One benefit of the present invention is that the absorbent capacity and other relevant parameters of the monolithic absorbent structure used therein can be determined in advance with great precision. This means that in a series of absorbent articles as claimed, variations regarding absorbency parameters such as absorbent capacity, rate of absorption (body liquid uptake) etc. can be reduced since each monolithic porous absorbent structure of the series displays the same spatial arrangement of pores.
  • the invention also provides a series consisting of a plurality of disposable absorbent products such as a diaper, pant diaper, panty liner, sanitary napkin or incontinence device, each absorbent product comprising a liquid-pervious topsheet, a backsheet and an absorbent layer arranged between the liquid-pervious topsheet and the backsheet,
  • the absorbent layer comprises or consists of a monolithic porous absorbent structure made from a hydrogel-forming material
  • each monolithic porous absorbent structure was obtained from a common process by depositing and photopolymerizing, layer by layer, a photopolymerizable composition, and wherein each monolithic porous absorbent structure of the series displays the same spatial arrangement of pores.
  • LBL photopolymerization such as digital light processing (DLP) preferably utilizes a projector to selectively cure/crosslink a liquid photopolymer in a vat by light-activated polymerization. In this manner a crosslinked superabsorbent polymer/hydrogel can be produced.
  • DLP digital light processing
  • the monolithic absorbent structures obtained will be useful as or in the absorbent layer of the claimed hygiene absorbent article. Likewise it is possible to use them as or in an acquisition layer
  • the absorbent layer comprises or consists of a monolithic absorbent structure made from a hydrogel-forming material
  • the absorbent structure comprises at its surface apertures
  • the method comprising the step of manufacturing the absorbent structure by photopolymerizing, layer by layer, a photopolymerizable composition.
  • the monolithic absorbent structure has two major opposing sides comprising each at their surface apertures, wherein the apertures of the first major side and the apertures of the second major side are connected by open pores such as channels, which are preferably interconnected.
  • (a1 ) monofunctional monomers having one double bond the monomers being selected from acrylic acid, salts thereof, methacrylic acid, salts thereof, sulfonic acid derivatives of acrylamide such as 2-acrylamido-2-methylpropane sulfonic acid, salts thereof, vinyl sulfonic acid, salts thereof, styrene sulfonic acid, salts thereof, acrylonitrile, phosphonic acid-derivatives of acrylamide and (meth)acrylic acid such as dimethyl(methacryloyloxy)methyl phosphonic acid, salts thereof, vinyl alcohol, vinylacetate, vinyl pyrrolidone, vinyl morpholinone, vinyl pyridine, vinyl ethers, maleic acid, salts and anhydrides thereof, ;
  • (a2) (meth)acrylic esters, in particular hydroxyalkyl esters of (meth)acrylic acid such as 2-hydroxyethyl methyacrylate (HEMA) and/or 2-hydroxypropyl methyacrylate (HPMA), and (meth)acrylamide, in particular N-alkyl (meth)acrylamide such as N- isopropyl(meth)acrylamide; and (a3) multifunctional monomers (having e.g.
  • HEMA 2-hydroxyethyl methyacrylate
  • HPMA 2-hydroxypropyl methyacrylate
  • (meth)acrylamide in particular N-alkyl (meth)acrylamide such as N- isopropyl(meth)acrylamide
  • multifunctional monomers having e.g.
  • two or three terminal double bonds preferably acrylic monomers having two terminal double bonds, wherein two (meth)acrylate or (meth)acrylamide units are linked by a linking unit such as alkylene or (poly)ethylene glycol, such as methylenebisacrylamide, polyethylene glycol diacrylate (PEGDA), or polyethylene glycol dimethyacrylate (PEGDMA); and/or
  • the photopolymerizable composition comprises the components (a) to (e) in the following amounts based on the total weight of the composition: total amount of (a) and (a') 35 to 99.95 wt.-%; preferably 40 to 99.5 wt.-%, more preferably 50 to 99.0 wt.-%, more preferably 70 to 99.0 wt.-% or 70 to
  • Absorbent article obtainable by the method as defined in any of items 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14 or 15.
  • each absorbent product comprising a liquid-pervious topsheet, a backsheet and an absorbent layer arranged between the liquid-pervious topsheet and the backsheet, wherein the absorbent layer comprises or consists of a monolithic porous absorbent structure made from a hydrogel-forming material,
  • each monolithic porous absorbent structure was obtained from a common process by depositing and photopolymerizing, layer by layer, a photopolymerizable composition
  • each monolithic porous absorbent structure of the series displays the same spatial arrangement of pores.
  • Figures 1 and 2 both show a monolithic porous absorbent structure made from a hydrogel-forming material in accordance with the present invention.
  • the absorbent structure is shown as obtained from the DLP 3D printer while the structure to the right is in a swollen state.
  • Figures 3A and 3B show a diamond lattice and a 3D-MSE structure (based on 3- dimensional Minimal Surface Equations) which can be used in CAD models for preparing a monolithic porous absorbent structure in accordance with the present invention.
  • the present invention relates to a method of making an absorbent article such as diaper, pant diaper, panty liner, sanitary napkin or incontinence protection, the absorbent article comprising a liquid-pervious topsheet, a backsheet and an absorbent structure arranged between the liquid-pervious topsheet and the backsheet,
  • the absorbent layer comprises or consists of a monolithic absorbent structure made from a hydrogel-forming material
  • the absorbent structure comprises at its surface apertures
  • absorbent article we understand articles capable of absorbing body fluids such as urine, watery faeces, female secretion or menstrual fluids. These absorbent articles include, but are not limited to diapers, pant diapers, panty liners, sanitary napkins or incontinence protection (as for instance used for adults).
  • Such absorbent articles have a liquid-pervious coversheet (topsheet) which during use is facing the wearer's body. They further comprise on the opposite side of the absorbent article a coversheet (backsheet), which during use is normally facing the wearer's garment and is preferably liquid-impervious.
  • the backsheet can for instance comprise or consist of a plastic film, a plastic-coated nonwoven or a hydrophobic nonwoven.
  • At least one further layer of a web or foam material can be arranged between the absorbent layer and the topsheet.
  • This or these layer(s) may for instance
  • it may be at least one layer of a web or foam material that is effective in quickly conducting incoming liquid further away from the topsheet and spreading the liquid in a perpendicular direction to the topsheet surface to make optimum use of the available surface of the absorbent body.
  • a suitable topsheet may be manufactured from a wide range of materials such as woven and nonwoven materials (e.g. a nonwoven web of fibers), polymeric materials such as apertured plastic films, e.g. apertured-formed thermoplastic films and hydroformed thermoplastic films; porous foams; reticulated foams; reticulated thermoplastic films; and thermoplastic scrims.
  • Suitable woven and nonwoven materials can be comprised of natural fibers or from a combination of natural and synthetic fibers.
  • suitable synthetic fibers which may comprise all or part of the topsheet include but are not limited to polyamide (e.g. nylon), acrylic (e.g. polyacrylonitrile), aromatic polyamide (e.g. aramide), polyolefin (e.g.
  • Synthetic fibers that contain more than one type of repeat unit can result from combining repeat units at the molecular level within each macromolecular strand (copolymer), between macromolecular strands (homopolymer blends), or combinations thereof (copolymer blends); or they can result from combining repeat units at a higher scale level with distinct nanoscopic, microscopic, or macroscopic phases (e.g., multicomponent fibers).
  • Each component of a multicomponent fiber can comprise a homopolymer, a copolymer, or blends thereof.
  • Bicomponent fibers are common versions of multicomponent fibers.
  • the two or more types of repeat units in a copolymer can be arranged randomly or in alternating blocks of each type. Blocks of different types of repeat units can be jointed to one another at their respective ends (block copolymers) or between the respective end of at least one block (graft copolymers).
  • Nonwoven materials can be formed by direct extrusion processes during which the fibers and the nonwoven materials are formed at about the same point in time, or by preformed fibers which can be laid into nonwoven materials at a distinctly subsequent point in time.
  • Exemplary direct extrusion processes include but are not limited to: spunbonding, meltblowing, solvent spinning, electrospinning and combinations thereof typically forming layers.
  • Exemplary "laying" processes including wet laying and dry laying.
  • Exemplary dry laying processes include but are not limited to air laying, carding and combinations thereof typically forming layers. Combinations of the above processes yield nonwovens commonly called hybrides or composites.
  • the fibers in a nonwoven material are typically joined to one or more adjacent fibers at some of the overlapping junctions. Fibers can be joined by mechanical entanglement, by chemical bond or by combinations thereof.
  • the optional absorbent layer may comprise any absorbent material that is generally compressible, conformable, non-irritating to the wearer's skin and capable of absorbing and retaining liquids such as urine and other body exudates.
  • the absorbent layer may be partially or totally surrounded by a core wrap. In some specific products it may also be totally omitted.
  • the backsheet prevents the exudates absorbed by the absorbent layer from soiling other external articles that may contact the absorbent article, such as bed sheets and undergarments.
  • the backsheet is substantially impervious to liquids (e.g., urine) and comprises a laminate of a nonwoven and a thin plastic film such as a thermoplastic film having a thickness of about 0.012 mm to about 0.051 mm.
  • Suitable backsheet films include those manufactured by Tredegar Industries Inc. of Terre Haute, Ind. and sold under the trade names X15306, X10962, and X10964.
  • Other suitable backsheet materials may include breathable materials that permit vapors to escape from the absorbent article while still preventing exudates from passing through the backsheet.
  • Exemplary breathable materials may include materials such as woven webs, nonwoven webs, composite materials such as film- coated nonwoven webs, and microporous films.
  • the absorbent layer comprises or consists of a monolithic absorbent structure made from a hydrogel-forming material.
  • monolithic means that the porous structure is formed as a single piece.
  • the monolithic absorbent structure may be used as the sole material forming the absorbent layer.
  • the absorbent layer may comprise further liquid-absorbent materials commonly used in disposable diapers and other absorbent materials such as absorbent cellulosic fibers, e.g. comminuted wood pulp, which is generally referred to as air felt or fluff.
  • absorbent cellulosic fibers e.g. comminuted wood pulp
  • suitable absorbent materials include creped cellulose wadding; melt-blown polymers, including co-form; chemically stiffened, modified or crosslinked cellulosic fibers; tissue, including tissue wraps and tissue laminates, absorbent foams, absorbent sponges, superabsorbent polymers "SAP" (such as SAP fibers or SAP particles), other absorbent gelling materials, or any other known absorbent materials or combinations of materials.
  • SAP superabsorbent polymers
  • the monolithic absorbent structure can for instance be used in conjunction with cellulosic fibers such as fluff, other absorbent gelling materials and/or SAP fibers and/or SAP particles.
  • the absorbent layer is composed of the one (or more) monolithic absorbent structure(s) and SAP particles and/or SAP fibers (hereinafter "SAP"), as exemplified by the following four options: 1 .
  • SAP SAP particles and/or SAP fibers
  • channels In certain regions (“channels") that extend from the center of the absorbent layer to its upper side (facing the skin of the wearer) and lower side (facing the backsheet) less SAP is provided than in the remaining regions. These regions (“ channels”) help to distribute the liquid over a larger area within the core.
  • Extra SAP is placed on top of the absorbent layer, i.e. the upper side facing the skin of the wearer, and below the absorbent layer, i.e. on the lower side facing the backsheet.
  • Extra SAP is placed around the circumference ("border") of the absorbent layer ("absorbent core").
  • the SAP border acts as a leakage barrier.
  • the monolithic absorbent structure has two major opposing sides comprising each at their surface apertures, wherein the apertures of the first major side and the apertures of the second major side are connected by open pores such as channels, which are preferably interconnected.
  • the amount of closed porosity is less than 10 vol.-%, preferably less than 8 vol.-%, more preferably less than 5 vol.-%, even more preferably less than 3 vol.-%, even more preferably less than 1 vol.-%, and most preferably 0 vol.-%.
  • the absorbent structure also does not contain any residues of blowing agent as usually required for generating porosity.
  • Rhino - Surface modelling
  • Mathematica ShapeJS - Voxel based Java modelling tool online
  • Meshmixer Meshlabs
  • Netfab Netfab
  • MathMod Print studio
  • Fusion 360 there are no specific limitations as to the diameter of the apertures at the surface of the monolithic absorbent structure or, if present, the pores, such as channels (in the following referred to as "pores/channels") preferably connecting the same.
  • Suitable diameters can be selected by a person skilled in the art having regard to known criteria such as mechanical stability, capillary forces, a sufficiently high absorption speed, etc.
  • the apertures or, if present, the pores/channels connecting the same have a diameter of at least 0.001 mm, preferably 0.01 mm to 3 mm, more preferably 0.1 mm to 2 mm.
  • pores is used to denote any sort of passageway/s connecting the apertures at the surface of the absorbent structure.
  • the pores have the form of channels.
  • channels typically have clearly defined walls guiding the flow of body liquids through the channels.
  • the total open porosity can be easily determined prior to the manufacture of the monolithic absorbent structure.
  • the total open porosity, e.g. channel volume, of the dry absorbent structure is 10% to 99% of the volume of the monolithic absorbent structure, preferably 20% to 95%, more preferably 30% to 90%, e.g. 70% to 90%.
  • the total porosity is the sum of open porosity (measurable by intrusion methods, e.g. mercury intrusion) and closed porosity (measurable by microscopic image analysis or calculable from Archimedes measurements, when the bulk density is measured and the theoretical density is known).
  • each 2 x 2 x 2 mm 3 volume element of the monolithic absorbent structure has an open porosity, e.g. channel volume, of 10% to 99%, preferably 20% to 95%, more preferably 30% to 90%, e.g. 70% to 90%.
  • the apertures or the pores, such as channels have a regular shape and/or a regular arrangement.
  • the minimum wall thickness i.e. the minimum distance from one pore/channel to the next pore/channel is not more than 500 ⁇ , e.g. less than 300 ⁇ .
  • the wall thickness can for instance range from 10 m to 500 ⁇ .
  • the monolithic absorbent structure has a diamond lattice or 3D- MSE structure (based on 3-dimensional Minimal Surface Equations) such as a gyroid-like structure, as shown in Figures 3A and 3B, respectively.
  • the embodiments shown in these figures have the same cell size (2 mm) but a different thickness of the structure elements, i.e. 200 ⁇ in figure 3A and 80 ⁇ (wall thickness) in figure 3B.
  • the present invention makes it possible to provide also the absorbent layer itself, or more specifically the monolithic absorbent structure used therein, with this function. Accordingly, in one preferred embodiment of the invention, the pores, such as channels, are arranged such as to enhance lateral distribution of body fluids away from the point of insult by the body fluid.
  • the outer shape and the length, width and thickness of the monolithic absorbent structure as long as the same can be fitted into the absorbent article, either as the absorbent layer or an essential part thereof.
  • Preferably at least 50% by weight (e.g. at least 80% by weight) of the absorbent materials present in the absorbent layer are made up of the monolithic absorbent structure.
  • the absorbent structure has a thickness from 1 mm to 20 mm.
  • the absorbent structure resulting from the claimed method preferably has a top view
  • the maximum size naturally depends on the size of the (disposable) absorbent article into which it is to be fitted.
  • the thickness of the absorbent structure is no more than 20% (preferably no more than 15%/10%) of the smaller value of the length or width of the absorbent structure.
  • the step of photopolymerizing the photopolymerizable composition is conducted by rapid prototyping techniques such as stereolithography (SLA), digital light processing (DLP), or continuous liquid interphase production (CLIP).
  • rapid prototyping techniques such as stereolithography (SLA), digital light processing (DLP), or continuous liquid interphase production (CLIP).
  • Stereolithography is a form of 3D printing technology used for creating models, prototypes, patterns, and production parts in a layer-by-layer fashion using photopolymerization. Those polymers then make up the body of a three-dimensional solid.
  • Stereolithography is an additive manufacturing process that works by focusing an ultraviolet (UV) laser on to a vat of photopolymer resin. With the help of computer-aided manufacturing or computer-aided design software (CAM/CAD), the UV laser is used to draw a pre-programmed design or shape onto the surface of the photopolymer vat. Because photopolymers are photosensitive under ultraviolet light, the resin is solidified and forms a single layer of the desired 3D object. This process is repeated for each layer of the design until the 3D object is complete.
  • UV ultraviolet
  • CAM/CAD computer-aided design software
  • Digital Light Processing is a similar process to stereolithography (SLA) in that it is a 3D printing process that works with photopolymers.
  • SLA stereolithography
  • the major difference is the light source.
  • DLP uses a more conventional light source, such as an arc lamp, with a liquid crystal display panel or a deformable mirror device (DMD), which is applied to the entire surface of the vat of photopolymer resin in a single pass, generally making it faster than SLA.
  • DMD deformable mirror device
  • SLA stereolithography
  • DLP produces highly accurate parts with excellent resolution.
  • One advantage of DLP over SLA is that only a shallow vat of resin is required to facilitate the process, which generally results in less waste and lower running costs. If used with a supporting structure, any geometry is possible. This technology is also available for the personal printer sector, and it is appealing due to its relatively low investment costs.
  • DLP resolution of DLP is sufficient to form microporous structures with pores small enough to achieve a monolithic absorbent structure making use of capillary forces.
  • DLP is one of the fastest 3D printing methods available.
  • the DLP projector displays an image, depicting a cross section of a 3D part onto the surface of the resin.
  • the exposed resin solidifies to a predetermined thickness forming one layer, hence each layer prints instantly, regardless of the object's size measured in the X/Y-plane or the object's geometrical complexity.
  • the main factor that limits the speed of DLP printing is that the build plate needs to be lifted and repositioned before a new layer can be printed. There are two reasons why the object must be lifted before a new layer can be printed: (1 ) The object is lifted from the bottom surface of the resin vat in order to allow for new resin to flow in between the previous layer and the surface on which the layer/image is projected.
  • Carbon 3D has invented a DLP printer which can print continuously without repositioning the building plate between each layer. Carbon 3D's invention is called CLIP, Continuous Liquid Interface Production.
  • Continuous Liquid Interface Production (CLIP; originally Continuous Liquid Interphase Printing) is a method of 3D printing that uses photopolymerization to create solid objects of a wide variety of shapes using resins. It was invented by Joseph DeSimone, Alexander and Nikita Ermoshkin and Edward T. Samulski and was originally owned by EiPi Systems, but is now being developed by Carbon 3D.
  • the continuous process begins with a pool of liquid photopolymer resin. Part of the pool bottom is transparent to ultraviolet light (the "window"). An ultraviolet light beam shines through the window, illuminating the precise cross-section of the object. The light causes the resin to solidify. The object rises slowly enough to allow resin to flow under and maintain contact with the bottom of the object.
  • An oxygen-permeable membrane lies below the resin, which creates a "dead zone" (persistent liquid interface) preventing the resin from attaching to the window (photopolymerization is inhibited between the window and the polymerizer). Unlike stereolithography, the printing process is continuous.
  • Carbon 3D has replaced the window in the bottom of the resin vat with a special window that is transparent to light and permeable to oxygen.
  • the oxygen acts as a counterbalance to the UV light, hence preventing the hardening of the photopolymer.
  • CLIP creates a thin layer of uncured resin between the window and the object (referred to as "dead-zone" by Carbon 3D).
  • the uncured layer eliminates the need for repositioning the build plate since the printed object is never in direct contact with the window in the bottom of the resin vat.
  • the photopolymerizable composition used in the present invention comprises
  • a photopolymerizable monomer selected from monomers (a1 ), (a2) and (a3) In order to adjust the viscosity of the photopolymerizable composition one may also use (a') an oligomer obtained by pre-polymerizing at least one photopolymerizable monomer selected from monomers (a1 ), (a2) and (a3).
  • Monomer (a1 ) is preferably a highly hydrophilic monomer with ionizable groups which induces an osmotic effect and high degree of swelling in the gel. More preferably it is provided in the salt form. More specifically, monomer (a1 ) can be selected from monofunctional monomers having one double bond, the monomers being selected from acrylic acid, salts thereof, methacrylic acid, salts thereof, sulfonic acid derivatives of acrylamide such as 2-acrylamido-2-methylpropane sulfonic acid, salts thereof, vinyl sulfonic acid, salts thereof, styrene sulfonic acid, salts thereof, acrylonitrile, phosphonic acid derivatives of acrylamide and (meth)acrylic acid such as dimethyl(methacryloyloxy)methyl phosphonic acid, salts thereof, vinyl alcohol, vinylacetate, vinyl pyrrolidone, vinyl morpholinone, vinyl pyridine, vinyl ethers, maleic acid, salts and anhydrides
  • Monomer (a2) represents an additional hydrophilic monomer which can be used for improving mechanical properties, elasticity, stiffness, degradability, etc.
  • monomer (a2) can be selected from (meth)acrylic esters, in particular hydroxyalkyl esters of (meth)acrylic acid such as 2-hydroxyethyl methyacrylate (HEMA) and/or 2-hydroxypropyl methyacrylate (HPMA), and (meth)acrylamide, in particular N-alkyl (meth)acrylamide such as N- isopropyl(meth)acrylamide.
  • Monomer (a3) is preferably used in order to enhance the formation of a crosslinked, insoluble, swellable polymer network.
  • monomer (a3) can be selected from multifunctional monomers (having e.g. two or three terminal double bonds), preferably acrylic monomers having two terminal double bonds, wherein two (meth)acrylate or
  • (meth)acrylamide units are linked by a linking unit such as alkylene or (poly)ethylene glycol, such as methylenebisacrylamide, polyethylene glycol diacrylate (PEGDA), or polyethylene glycol dimethyacrylate (PEGDMA).
  • a linking unit such as alkylene or (poly)ethylene glycol, such as methylenebisacrylamide, polyethylene glycol diacrylate (PEGDA), or polyethylene glycol dimethyacrylate (PEGDMA).
  • PEGDA polyethylene glycol diacrylate
  • PEGDMA polyethylene glycol dimethyacrylate
  • the absorbent structure can also be obtained from using monomer (a3) as the sole monomer.
  • the photopolymerizable composition may comprise (b) a photoinitiator. In one further preferred embodiment it comprises optionally (c) a UV absorber (if UV light is used as a light source in the photopolymerization step). Then (b) and (c) may also be present together.
  • the photopolymerizable composition may further comprise (d) optionally one or more other additives than (b) or (c); and (e) optionally one or more solvents.
  • the hydrogel-based absorbent structure preferably comprises or consists of (co)polymers resulting from photopolymerizing one or more of the aforementioned monomers (a1 ), (a2) and (a3).
  • all monomers present in the photopolymerizable composition are selected from type (a1 ), type (a2) or type (a3), respectively. In one further embodiment, all monomers present in the photopolymerizable composition are selected from types (a1 ) and (a2), (a1 ) and (a3), or (a2) and (a3).
  • one or more monomers with ionic groups can be used in the monomer mixture (a) such as ionic (meth)acrylates, e.g. (meth)acrylic acid (-COOH), sulphonated (meth)acrylates (-SO3H) or phosphonates (-RPO3H). If the above stated groups are present in the salt form, osmotic effects and a higher degree of swelling is obtained.
  • a part of PEGDA is replaced with a hydrophilic monoacrylate monomer, such as hydroxyethylacrylate
  • polyester-(meth)acrylates or polyurethane-(meth)acrylates could be added.
  • the hydrogel-based absorbent structure comprises, or consists of, the following (co)polymers: poly(acrylic acid) and salts thereof; poly(methacrylic acid) and salts thereof; copolymers of acrylic and/or methacrylic acid with acrylamide, vinyl alcohol, acrylic esters, vinyl pyrrolidone, vinyl sulfonic acids, vinyl acetate, vinyl morpholinone and vinyl ethers; copolymers of maleic anhydride with ethylene, isobutylene, styrene, vinyl alcohol, vinyl ethers, vinyl pyrrolidone, and vinyl morpholinone, and salts thereof; polyvinyl alcohol); poly(acrylamides) and partially hydrolyzed poly(acrylamides), and salts thereof; polyvinyl ethers); polyvinyl sulfonic acid) and salts thereof, poly(styrene sulfonic acid) and salts thereof; polyvinyl pyrrolidone); polyvinyl morpholin
  • the photopolymerizable composition may further comprise one or more (b) photoinitiators.
  • Any photoinitiator can be used as long as it is able to convert absorbed light energy, UV or visible light, into chemical energy in the form of initiating species, e.g. free radicals or cations and shows the necessary solubility in the photopolymerizable composition.
  • Typical classes of such compounds include phenones including acetophenones, hydroxyacetophenones and benzophenones; bisimidazole compounds; oxim compounds; benzil and benzoin compounds; cationic photoinitiators; thioxantones and phosphineoxides.
  • the photoinitiator may be selected from commercially available photoinitators.
  • phenone compounds include, anisoin, anthraquinone, anthraquinone- 2-sulfonic acid, 2-hydroxy-2-methyl-1 -phenylpropan-1 -one, benzyl dimethyl ketal, 2- hydroxy-1 -[4-(2-hydroxyethoxy)phenyl]-2-methylpropan-1 -one, 2-methyl-1 -(4- methylthiophenyl)-2-morpholinopropan-1 -one, 1 -hydroxycyclohexyl-phenyl-ketone, 1 - hydroxy-4-methoxyphenyl-phenyl-ketone, 2-benzyl-2-dimethylamino-1 -(4- morpholinophenyl)butan-1 -one, 2-(2-methylbenzyl)-2 dimethylamino-1 -(4- morpholinophenyl)butanone, 2-(3-methylbenzyl)-2-dimethylamino-l-(4- morpholinophenyl
  • acetophenone compounds include acetophenone, diethoxyacetophenone, 3'-hydroxyacetophenone, 4'-hydroxyacetophenone, 4- hydroxybenzophenone, 1 -hydroxycyclohexyl phenylketone, 2-hydroxy-2- methylpropiophenone, 2-methyl-4'-(methylthio)-2-morpholino-propiophenone, phenanthrenequinone, 4'-phenoxyacetophenone
  • benzophenone compound examples include benzophenone, 2- methylbenzophenone, 3,4-dimethylbenzophenone, 3-methylbenzophenone, 3- hydroxybenzophenone, 4,4'-dihydroxybenzophenone, methyl o-benzoylbenzoate, 4- phenylbenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 2,5- dimethylbenzophenone, 3,3',4,4'-bis(diethylannino)benzophenone, 4,4'-tetra(tert- butylperoxycarbonyl)benzophenone, and 2,4,6-trinnethylbenzophenone.
  • Examples of cationic photoinitiator compounds include bis(4-tert- butylphenyl)iodonium perfluoro-1 -butanesulfonate, bis(4-tert-butylphenyl)iodonium p- toluenesulfonate, bis(4-tert-butylphenyl)iodonium inflate, boc- methoxyphenyldiphenylsulfonium inflate, (tert-butoxycarbonylmethoxynaphthyl)- diphenylsulfonium inflate, (4-tert-butylphenyl)diphenylsulfonium inflate, diphenyliodonium hexafluorophosphate, diphenyliodonium nitrate, diphenyliodonium perfluoro-1 -butanesulfonate, diphenyliodonium p-toluenesulfon
  • acylphosphine oxide compound examples include 2,4,6- trimethylbenzoyldiphenylphosphine oxide.
  • Bis(2,4,6- trimethylbenzoyl)-phenylphosphineoxide is preferred as a photoinitiator.
  • This photoinitiator is also called BAPO and sold under the tradename Irgacure 819 (BASF, CIBA). Irgacure 819 works well in the light working range of the printer and has a good solubility in PEGDA.
  • sensitizer + hydrogen donator are used, e.g. the combination of phenone initiators such as Irgacure 2959 (2-Hydroxy-4 '-(2- hydroxyethoxy)-2-methylpropiophenone) and camphorquinone.
  • phenone initiators such as Irgacure 2959 (2-Hydroxy-4 '-(2- hydroxyethoxy)-2-methylpropiophenone) and camphorquinone.
  • the content of the photoinitiator in the photopolymenzable composition is usually from 0.05 to 1 .0 weight percent. When the content of the photoinitiator is in this range, a patterned resin layer having sufficient strength can be formed.
  • the photopolymenzable composition may further comprise one or more (c) UV absorbers.
  • the type of UV absorber is in principle not limited as long as it is capable of absorbing UV light, is soluble in the photopolymenzable composition and preferably shows low volatility. If UV light is used as light source in the photopolymerization step, it can be beneficial to use an UV absorber since the same reduces the penetration depth of the UV light rays. This prevents the photopolymenzable monomers and/or oligomers from starting to photopolymerize in areas in vicinity to the actual layer to be produced and thereby enhances the resolution of the structural features of the monolithic absorbent structure.
  • the UV absorber may be used singly or in combination.
  • the UV absorber may be an organic or an inorganic compound.
  • Typical commercially available examples of organic UV-absorber are benzotriazoles such as 2-(2'-Hydroxy-5'- methylphenyl)benzotriazole, 2-(2'-Hydroxy-3'-tert-butyl-5'-methylphenyl)-5- chlorobenzotriazole, 2-(2'-Hydroxy-3',5'-di-tert-amylphenyl)benzotriazole, 2-(2'- Hydroxy-5'-tert-octylphenyl)benzotriazole, 2,2'-Methylenebis[6-(2H-benzotriazol-2-yl)- 4-tert-octyl phenol], 6-(2-benzotriazolyl)-4-tert-octyl-6'-tert-butyl-4'-methyl-2,2'-
  • the content of the UV absorber in the photopolymenzable composition is usually 0 to 1 weight percent, preferably 0.1 to 1 weight percent.
  • the photopolymenzable composition may further optionally comprise (d) one or more other additives than (b) or (c) to improve or modify properties such as flowability, dispensing or printing property, storage property, curing property and physical property after curing.
  • the component that may be contained in the composition as needed includes, for example, organic or inorganic filler, thixotropic agent, modifier, coloring agent such as pigment and dye, surfactant, preservative stabilizer, plasticizer, lubricant, defoamer, leveling agent, bases for neutralizing acidic ionizable groups, additives for improving the feature resolution of the photopolymers and the like; however it is not limited to these.
  • Bases for neutralizing acidic ionizable groups include for instance Na2CO3 or NaOH.
  • Other additives for improving the feature resolution of the photopolymers include TEMPO and TEMPO derivatives.
  • the photopolymenzable composition may further optionally comprise (e) one or more solvents for the purposes of improving the handling properties and adjusting the viscosity and the storage stability of the composition.
  • the solvent include: water; alcohols such as ethanol, propanol or butanol; alkylene glycol alkyl ethers, such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether, propylene glycol monomethyl ether acetate, propylene glycol
  • amides such as N ,N-dimethylformamide,N-methylacetamide,N, N- dimethylacetamide and N-methylpyrrolidone.
  • the photopolymenzable composition comprises the components (a) to (e) in the following amounts based on the total weight of the composition:
  • the amounts are as follows (a) and /or ( a ' ) 70 to 99.95 wt.-% (photopolymerizable monomer/ s and/or ol igomer /s);
  • the hydrogel-forming material is crosslinked during or after the photopolymenzation step.
  • the crosslinking is preferably achieved by using the aforementioned one or more multifunctional monomers (a3), optionally in combination with one or more monomers selected from type (a1 ) and/or one or more monomers selected from type (a2).
  • the hydrogel-forming material is crosslinked during or after the photopolymerization step such that the degree of crosslinking varies throughout the monolithic absorbent structure
  • LBL photopolymerization such as DLP makes it possible to vary the degree of crosslinking of the hydrogel material in any given point within the 3D Printed structure.
  • the possibility of varying the degree of crosslinking in turn allows for controlling the absorption speed and/or the absorption capacity in any given point in a 3D printed structure. This makes it possible to more effectively utilize the available absorption capacity of the monolithic absorbent structure.
  • an absorbent structure with a varying degree of crosslinking encompasses the following aspects.
  • the absorbent structure displays a gradient in the thickness direction in terms of the degree of crosslinking. This means that on one side of the absorbent structure, preferably the one facing the skin of the user, the degree of crosslinking is higher than the degree of crosslinking on the other side of the absorbent structure, preferably the one facing the garment during use of the absorbent article.
  • the degree of cross-linking gradually lowers from one side toward the other side.
  • the absorbent structure comprises at least two clearly distinguishable layers in the thickness direction, one layer having a higher degree of crosslinking than the other one.
  • the layer having a higher degree of crosslinking faces the skin of the user.
  • the monolithic absorbent structure displays a gradient in the degree of crosslinking that extends from at least one outer to the inner portion of the structure.
  • the external portions of the absorbent structure which come into contact with body liquids first, have a low degree of crosslinking, whereas the degree of crosslinking is higher in the central portions of the absorbent structure (or vice versa).
  • External portions having a low degree of crosslinking ensure that the absorbent structure quickly absorbs body liquids (in order to prevent rewet) which then can be further distributed to and stored by the inner portions of the structure.
  • the inner portions with the higher degree of crosslinking contribute to the mechanical stability of the absorbent structure.
  • One benefit of absorbent products in accordance with this aspect is that they comprise portions that can receive the body liquid without causing gel blocking and other portions that start to absorb only when the amount of absorbed liquid approaches the maximum absorbent capacity of the product.
  • areas with a higher degree of crosslinking are likely to show a lower absorption rate and/or a lower absorption capacity while areas with the lower degree of crosslinking are likely to show the opposite behaviour, i.e. a higher absorption rate and/or higher absorption capacity.
  • the method of making the absorbent article comprises the steps of (i) providing a preferably liquid-impervious backsheet,
  • the support structures normally serve two purposes. First, they firmly attach the printed object to the build platform. Secondly, the structures support parts of the 3D printed object that are not self-supporting or have overhang.
  • a DLP printer can print objects with approximately 45° overhang without support structures depending on the geometry. It is possible to print parts using DLP without support structures given that the object has (1 ) a flat surface facing the build platform. The flat surface must be large enough so that the 3D object becomes firmly attached to the build platform or (2) no overhangs exceeding 45°.
  • the monolithic absorbent structure obtained in the LBL photopolymerization step (ii) is subjected to known purification steps such as removal of volatile starting materials, including solvents, for instance in vacuo, optionally under heating, and removal of non-volatile starting materials, e.g. by soaking the structure in suitable solvents such as 2-propanol (optionally in an ultrasonic bath).
  • suitable solvents such as 2-propanol (optionally in an ultrasonic bath).
  • the preformed structure is exposed to light irradiation after such purification steps in order to increase the degree of polymerization and/or the degree of crosslinking.
  • the build plate is moved to a perforated plate where residual resin(s) and, if present, solvent are sucked out from the structure.
  • the residual material is filtered and reused.
  • the structure is then irradiated with light (e.g. UV) in order to cure any residual monomer(s) and/or oligomers(s) stuck on the surface of the structure.
  • the build plate is moved to a closed chamber.
  • the building plate rotates within the chamber in order to centrifuge out the uncured monomer(s) and, if present, the solvent.
  • the structure is then irradiated with light (e.g. UV) in order to cure any residual monomer(s) and/or oligomers(s) stuck on the surface of the structure.
  • the build plate is moved to a perforated plate.
  • the build plate presses the geometry onto the perforated plate in order to squeeze out uncured monomer(s) and the solvent, if present.
  • the structure is then irradiated with light (e.g. UV) in order to cure any residual monomer(s) and/or oligomers(s) stuck on the surface of the structure.
  • light e.g. UV
  • the monolithic absorbent structure obtained can be rendered more hydrophilic by the use of wetting agents.
  • Wetting agents could either be used in a post-processing step or be mixed into the photopolymerizable composition prior to printing.
  • the wetting agents should preferably be mixed into the resin prior to printing in order to avoid time-consuming after-treatment of the 3D-printed structure.
  • wetting agents in DLP technology reference can be made to "New 3D printing technique to eliminate the need for multiple 3D printers", available at: http://www.3ders.orq/articles/20131 Q30-new-3d-printinq-techniaue-to-eliminate-the- need-for-multiple-3d-printers.html (Oct. 13, 2013).
  • the present invention also relates to the absorbent article obtainable by the method as defined in the description and the appended claims.
  • Another aspect of the invention relates to a series consisting of a plurality of disposable absorbent products such as a diaper, pant diaper, panty liner, sanitary napkin or incontinence device, each absorbent product comprising a liquid-pervious topsheet, a backsheet and an absorbent layer arranged between the liquid-pervious topsheet and the backsheet,
  • the absorbent layer comprises or consists of a monolithic porous absorbent structure made from a hydrogel-forming material
  • each monolithic porous absorbent structure was obtained from a common process by depositing and photopolymerizing, layer by layer, a photopolymerizable composition
  • each monolithic porous absorbent structure of the series displays the same spatial arrangement of pores.
  • the step of depositing and photopolymerizing a photopolymerizable composition is conducted in accordance with a predetermined 3D model and the resulting spatial arrangement of pores is in accordance with this 3D model.
  • the same consists of at least 10 disposable absorbent products (e.g. 10, 15, 20, 15, 30, 35, 40, 45, 50, 60, 70 , 80 , 90 or 100 disposable absorbent products) wherein the total porosity of each monolithic porous absorbent structure does not differ by more than 20%, preferably not more than 15%, more preferably not more than 10%, preferably not more than 8%, more preferably not more than 5% from the mean total porosity of all monolithic porous absorbent structures of this series.
  • disposable absorbent products e.g. 10, 15, 20, 15, 30, 35, 40, 45, 50, 60, 70 , 80 , 90 or 100 disposable absorbent products
  • each monolithic porous absorbent structure was obtained from a common process step as defined in the present description and the method claims.
  • One benefit of the present invention is that the absorbent capacity and other relevant parameters of the monolithic absorbent structure used therein can be determined in advance with great precision. This means that in a series of absorbent articles as claimed, variations regarding absorbency parameters such as absorbent capacity, rate of absorption (body liquid uptake) etc. can be reduced since each monolithic porous absorbent structure of the series displays the same spatial arrangement of pores.
  • the invention also relates to the use of a monolithic absorbent structure obtainable by a method as defined in the present description and the appended claims in an absorbing core of a wearable absorbent article.
  • BurnlnExposureSec Exposure time for the Burnln layers.
  • the Burnln layers are used to build a solid foundation on which to build the model.
  • BurnlnLayers Number of Burnln layers for which the burn-in settings apply
  • FirstExposureSec Exposure time for the first layer.
  • the first layer is used to make sure that the model adheres to the build plate.
  • ModelExposureSec Exposure time for the remaining layers (all layers after the burn-in layers)
  • PEGDA 80 g was weighed into a brown bottle. A magnetic stirring bar was also placed into the bottle. Irgacure 819 (357 mg) and 2-(2H-Benzotriazol-2-yl)-4,6-bis(1 - methyl-1 -phenylethyl)phenol (160 mg) were weighed separately. The light in the room was turned off, and Irgacure 819 was added to the brown bottle, which was subsequently closed with a black lid.
  • the bottle was placed in a water bath of ca. 40 °C, and the mixture was stirred for 30 min. Light exposure was avoided at all times.
  • the printer should be placed in a red light lab with filters.
  • the Ember DLP® 3D Printer was used to produce the absorbent structure through photolithography in a layer-by-layer fashion.
  • a digital light-processing (DLP) chip (DLP® 0.45" WXGA DMD) was used to create active and reflective dynamic photomasks from a CAD drawing.
  • the CAD drawing was designed to provide a diamond-like lattice of the type shown in Fig. 3A which comprises regular, co-parallel channels, as seen from Fig. 1 and 2.
  • These dynamic photomasks were used to reproduce cross-sectional images of the 3D microstructure of the absorbent structure and project the patterns onto the hydrogel-forming composition using an LED light source (5W optical power, 405 nm wavelength).
  • the hydrogel-forming composition was cured by photopolymerization according to these patterns using the aforementioned curing settings. This process created a layer-by-layer 3D microstructure of the hydrogel-forming composition. Following the fabrication procedure, the absorbent structure was removed from the stage, gently washed using iso-propanol and air-dried.
  • the absorbent structure had an excellent 3D fine structure and was hollow throughout (see Figure 1 ).
  • the channels have a square shape with a side length of 1 .09 mm.
  • the CAD model was based on the diamond structure shown in Fig. 3A, wherein the length of the "bonds" connecting the center of the interconnected tetraeders was 3mm.
  • the wall thickness was 1 mm.
  • the total channel volume was estimated to be about 54% based on the data included into the CAD model: Volume of diamond structure including all walls: 15145,8 mm 3 .
  • the absorbent structure was sufficiently elastic. Swelling properties
  • the swelling properties in water were tested by immersing the dry absorbent structure (estimated water content according to Karl Fischer: 2%) in ion-free water (double distilled H 2 O) for 24h at 23°C. The length and the weight of the absorbent structure were measured before and after the water treatment.
  • Dry absorbent structure (before water treatment):
  • the swelling degree ((Wswoiien-Wdry) (Wdr y )) was 60%.
  • a photograph showing both the dry (left) and the swollen (right) absorbent structure is shown in Figure 2.

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Abstract

La présente invention concerne une méthode de fabrication d'un article absorbant tel qu'une couche, une couche-culotte, un protège-slip, une serviette hygiénique ou une protection contre l'incontinence, l'article absorbant comprenant une feuille supérieure perméable aux liquides, une feuille arrière et une couche absorbante disposée entre la feuille supérieure perméable aux liquides et la feuille arrière, la couche absorbante comprenant ou étant constituée d'une structure absorbante monolithique constituée d'un matériau formant un hydrogel, la structure absorbante comprenant à sa surface des ouvertures, la méthode comprenant l'étape de fabrication de la structure absorbante par photopolymérisation, couche par couche, une composition photopolymérisable ; un article absorbant pouvant être obtenu par cette méthode et une série de tels articles absorbants.
PCT/EP2017/066939 2017-07-06 2017-07-06 Article absorbant comprenant une structure absorbante monolithique comprenant un matériau formant un hydrogel WO2019007512A1 (fr)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113766971A (zh) * 2019-06-27 2021-12-07 庄信万丰股份有限公司 层状吸着剂结构
CN118578700A (zh) * 2024-08-06 2024-09-03 中天（中国）工业有限公司 一种液体卫生巾的制备方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1060722A2 (fr) 1999-06-18 2000-12-20 McNEIL-PPC, INC. Couche composée d'une couche de transfert et d'une couche supérieure unifiés
US6610900B1 (en) 1999-08-27 2003-08-26 Kimberly-Clark Worldwide, Inc. Absorbent article having superabsorbent in discrete pockets on a stretchable substrate
US20160175171A1 (en) * 2014-04-30 2016-06-23 Kimberly-Clark Worldwide, Inc. Absorbent article including a fluid distributing structure

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1060722A2 (fr) 1999-06-18 2000-12-20 McNEIL-PPC, INC. Couche composée d'une couche de transfert et d'une couche supérieure unifiés
US6610900B1 (en) 1999-08-27 2003-08-26 Kimberly-Clark Worldwide, Inc. Absorbent article having superabsorbent in discrete pockets on a stretchable substrate
US20160175171A1 (en) * 2014-04-30 2016-06-23 Kimberly-Clark Worldwide, Inc. Absorbent article including a fluid distributing structure

Non-Patent Citations (6)

* Cited by examiner, † Cited by third party
Title
ARTHUR BENS; HERMANN SEITZ ET AL.: "Non-toxic flexible photopolymers for medical stereolithography technology", RAPID PROTOTYPING JOURNAL, vol. 13, no. 1, 2007, pages 38 - 47
BANI H. CIPRIANO ET AL., MACROMOLECULES, vol. 47, 2014, pages 4445 - 4452, Retrieved from the Internet <URL:http://complexfluids.umd.edu/papers/111 2014q.pdf>
GAUVIN ET AL.: "Microfabrication of complex porous tissue engineering scaffolds using 3D projection stereolithography", BIOMATERIALS, vol. 33, no. 15, 2012, pages 3824 - 3834, XP028468793, DOI: doi:10.1016/j.biomaterials.2012.01.048
RICHARD GREENE, EMBER SETTINGS, 18 May 2016 (2016-05-18)
ROBERT GAUVIN ET AL: "Microfabrication of complex porous tissue engineering scaffolds using 3D projection stereolithography", BIOMATERIALS, ELSEVIER SCIENCE PUBLISHERS BV., BARKING, GB, vol. 33, no. 15, 27 January 2012 (2012-01-27), pages 3824 - 3834, XP028468793, ISSN: 0142-9612, [retrieved on 20120201], DOI: 10.1016/J.BIOMATERIALS.2012.01.048 *
SHI ET AL.: "3D printing scaffolds with hydrogel-forming materials for biomedical applications", EUROPEAN JOURNAL OF BIOMEDICAL RESEARCH, vol. 1, 2015, pages 3 - 8

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113766971A (zh) * 2019-06-27 2021-12-07 庄信万丰股份有限公司 层状吸着剂结构
CN113766971B (zh) * 2019-06-27 2024-03-22 庄信万丰股份有限公司 层状吸着剂结构
CN118578700A (zh) * 2024-08-06 2024-09-03 中天（中国）工业有限公司 一种液体卫生巾的制备方法

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