[go: up one dir, main page]

WO2023178636A1 - Partie centrale de couche - Google Patents

Partie centrale de couche Download PDF

Info

Publication number
WO2023178636A1
WO2023178636A1 PCT/CN2022/082954 CN2022082954W WO2023178636A1 WO 2023178636 A1 WO2023178636 A1 WO 2023178636A1 CN 2022082954 W CN2022082954 W CN 2022082954W WO 2023178636 A1 WO2023178636 A1 WO 2023178636A1
Authority
WO
WIPO (PCT)
Prior art keywords
diaper core
adhesive
edge
channel
base sheet
Prior art date
Application number
PCT/CN2022/082954
Other languages
English (en)
Inventor
Miaoru LING
Lori-Ann S. Prioleau
Clinton G. WIENER
Daniel S. Mcdonald
Mahfuza Begum Ali
Original Assignee
3M Innovative Properties Company
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 3M Innovative Properties Company filed Critical 3M Innovative Properties Company
Priority to PCT/CN2022/082954 priority Critical patent/WO2023178636A1/fr
Publication of WO2023178636A1 publication Critical patent/WO2023178636A1/fr

Links

Images

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
    • A61F13/53—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
    • A61F13/534—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 having an inhomogeneous composition through the thickness of the pad
    • 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
    • A61F13/539—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 characterised by the connection of the absorbent layers with each other or with the outer layers
    • 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
    • A61F2013/530481—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 having superabsorbent materials, i.e. highly absorbent polymer gel materials
    • 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
    • A61F13/539—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 characterised by the connection of the absorbent layers with each other or with the outer layers
    • A61F2013/53908—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 characterised by the connection of the absorbent layers with each other or with the outer layers with adhesive

Definitions

  • Diapers are a common item used by parents of children prior to the child being toilet trained.
  • disposable diapers are preferred for their convenience and superior absorbency.
  • Modern disposable diapers have an impervious back sheet, a middle absorbent layer and a body facing intake layer. Generally, the entire diaper is made on a diaper manufacturing line where the various components are assembled to make the diaper. However, a simpler diaper manufacturing line is possible when using a pre-made diaper core that accommodates the uptake of human waste since all the pulp and/or superabsorbent handling machinery to place the fluid management components for the absorbent layer on the diaper line can be eliminated.
  • a pre-made diaper core absorbent article has a back sheet, an absorbent core, and an intake layer formed into a premade pad.
  • the inventors have determined that by using a spot pattern of SAP particles, a center channel, specific classes of adhesives, and nonwoven materials to make the diaper core, excellent uptake of human wastes is possible even in a diaper core without any added pulp.
  • the invention resides in a diaper core having a nonwoven base sheet having a first side and an opposing second side; the first side being hydrophilic and the second side being hydrophobic; the base sheet having a longitudinal length, a cross-web direction width, a first edge in the longitudinal direction and a second opposing edge in the longitudinal direction; a plurality of water-based adhesive spots located on the first side and a plurality of SAP particles adhered to the first side by the water-based adhesive spots; a longitudinal center channel located in the middle one third of the width of the base sheet, the center channel having a channel width between a first channel edge in the longitudinal direction and a second channel edge in the longitudinal direction; and the center channel void of the plurality of water-based adhesive spots and the plurality of SAP particles; a nonwoven cover sheet positioned over the plurality of water-based adhesive spots and the plurality of SAP particles; the nonwoven cover sheet laminated to the base sheet by a plurality of ultrasonic bonds positioned along the first edge, the second edge,
  • FIG. 1 is a top view of the absorbent core showing the longitudinal channel, the sealed edges, and the hidden SAP spots.
  • FIG. 2 is an exploded view of the various layers in the diaper core.
  • FIG. 3 is a top view of the water based adhesive spots.
  • FIG. 4 is a cross section view of the SMS base sheet and the water based adhesive spots.
  • FIG. 5 is a top view of SAP particles adhered to the water based adhesive spots.
  • FIG. 6 is a side view of a longitudinal channel in the diaper core having three sealing lines.
  • FIG. 7 is a top view of the diaper core with the top sheet removed showing a hotmelt adhesive filament network over the SAP particles.
  • FIG. 8 is the print pattern for Example 16 in Table 3.
  • FIG. 9 is the print pattern for Example 17 in Table 3.
  • FIG. 10 is the print pattern for Example 18 in Table 3.
  • FIG. 11 is the print pattern for Example 19 in Table 3.
  • FIG. 12 is the print pattern for Example 20 in Table 3.
  • FIG. 13 is the print pattern for Example 21 in Table 3.
  • FIG. 14 is the print pattern for Example 22 in Table 3.
  • FIG. 15 is a schematic view of a manufacturing line to make the diaper core.
  • FIG. 16 is a schematic of a drop test fixture.
  • FIG. 17 is a schematic of a wicking fixture.
  • values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited.
  • a range of “about 0.1%to about 5%” or “about 0.1%to 5%” should be interpreted to include not just about 0.1%to about 5%, but also the individual values (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.1%to 0.5%, 1.1%to 2.2%, 3.3%to 4.4%) within the indicated range.
  • substantially refers to a majority of, or mostly, as in at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999%or more, or 100%.
  • substantially free of can mean having none or having a trivial amount of, such that the amount of material present does not affect the material properties of the composition including the material, such that the composition is about 0 wt%to about 5 wt%of the material, or about 0 wt%to about 1 wt%, or about 5 wt%or less, or less than or equal to about 4.5 wt%, 4, 3.5, 3, 2.5, 2, 1.5, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.01, or about 0.001 wt%or less.
  • the diaper core 10 has a nonwoven base sheet 12 having three layers; a spunbond layer 14 on a first side 16, a spunbond layer 18 on an opposing second side 20, and a middle layer 22 of a meltblown nonwoven.
  • the first side 16 is hydrophilic and the second side 20 is hydrophobic.
  • the base sheet 12 having a machine direction length 24, a cross machine direction width 26, a first edge 30 in the machine direction and a second opposing edge 32 in the machine direction.
  • a plurality of water-based adhesive spots 34 is located on the first side 16 and a plurality of SAP particles 36 is adhered to the first side 16 by the water-based adhesive spots 34.
  • a machine direction or longitudinal center channel 38 is located in the middle one third of the width of the base sheet and the center channel 38 having a channel width 40 between a first channel edge 42 in the longitudinal direction and a second channel edge 44 in the longitudinal direction.
  • the center channel 38 is void of the plurality of water-based adhesive spots 34 and the plurality of SAP particles 36.
  • a nonwoven cover sheet 46 is positioned over the plurality of water-based adhesive spots 34 and the plurality of SAP particles 36.
  • the nonwoven cover sheet 46 is laminated to the base sheet 12 by a layer of hotmelt adhesive filaments 48 applied over the plurality of SAP particles 36.
  • a plurality of ultrasonic bonds 50 positioned along the first edge 30, the second edge 32, the first channel edge 42 and the second channel edge 44 of the diaper core 10 hold the base sheet 12 and cover sheet together 46 and form the center channel 38.
  • the base sheet 12 in one embodiment has three layers: an 11 gsm spunbond layer 14 on a first side 16, an 11 gsm spunbond layer 18 on an opposing second side 20, and a 3 gsm middle layer 22 of a meltblown nonwoven.
  • the first side 16 is hydrophilic and the second side 20 is hydrophobic.
  • Preferably the middle melt blown layer 22 is also hydrophobic. Structuring the base sheet 12 in this manner keeps the water based adhesive spots 34 constrained to the hydrophilic spunbond layer 14 on the first side 16. This prevents bleed through of the water based adhesive and allows for less adhesive to be used since it does not penetrate all the way through the base sheet.
  • a suitable base sheet can be manufactured as a 25 gsm SMS nonwoven by a nonwoven manufacturer such as 3M Company.
  • suitable one, two, three, or multi-layer base sheets with a first side 16 that is hydrophilic and a second side 20 that is hydrophobic can be used.
  • the base sheet should be selected to have the water based adhesive spots penetrate the first side but not bleed through to the second side.
  • a two-layer spunbond -spunbond base sheet is possible.
  • a five-layer base sheet of spunbond -spunbond -meltblown -meltblown -spunbond is possible.
  • suitable basis weights for the base sheet are from 20 to 40 gsm, or 25 to 35 gsm.
  • the SAP should be applied as discrete spots or islands with surrounding areas free of SAP.
  • a pattern of water based adhesive spots was screen printed onto the hydrophilic spunbond layer 14.
  • the Tg should be low such as preferably below -20 degrees Celsius, or below -15 degrees Celsius.
  • the SBR should be listed as carboxylated, containing some carboxylation of some type introduced into the polymer to add some acid groups and polarity.
  • carboxylation of some type introduced into the polymer to add some acid groups and polarity.
  • carboxylation and Tg >-20 degrees Celsius Several samples were tested with Tg ⁇ -20 degrees Celsius and no carboxylation, and carboxylation and Tg >-20 degrees Celsius, and it was found in both materials, attachment of the SAP particles was poor. Therefore, desirable parameters of the water-based SAP adhesive are carboxylation of some degree, or carboxylation greater than >0.1%, or greater than >0.5%and Tg of less than ⁇ -20 degrees Celsius, or less than ⁇ -15 degrees Celsius.
  • Another embodiment with ability to lock the SAP particles in place is a cationic and silane containing emulsion polymer as disclosed in US patents 9, 828, 530 and US 10, 703, 927 both herein incorporated by reference in their entirety.
  • the cationic containing monomer likely interacts with the acid groups of the SAP and the silane containing monomer will react to form a covalent bond with the acid groups in the SAP.
  • the emulsion polymer comprises at least 1%by weight silane containing monomer and at least 2%by weight of the cationic containing monomer.
  • the water-based adhesive spots can be circular, oval, square, rhombus, diamond, polygon, or other suitable shape.
  • a spot length 100, L is longer in the longitudinal direction than a spot width 102, W, in the cross-web direction as shown in FIG. 8.
  • a spot length 100, L is shorter in the longitudinal direction than a spot width 102, W, in the cross-web direction as shown in FIG. 11.
  • a spot length, L is approximately the same in the longitudinal direction as a spot width, W, in the cross-web direction.
  • the spot length, L is 14.8 mm and is longer in the longitudinal direction than a spot width, W, of 6.9 mm. This locates the major axis of the adhesive spot along the longitudinal direction length of the diaper core and in Example 17, it was found this prevented high rewet, which is undesirable in a diaper core.
  • the water based adhesive spots in some embodiments can be arranged onto the base sheet in an ordered array versus a random placement.
  • the adhesive spots in the array may be aligned in an XY array such that there are a plurality of microchannels 104 devoid of SAP particles between the adhesive spots as shown in FIGS. 10-11.
  • Some of the microchannels are parallel to the longitudinal direction and some of the microchannels are parallel to the cross-web direction. Such a configuration may be less preferred since the fluid could easily follow a straight, shorter microchannel in the cross-web direction from the center channel 38 and travel easily to the edge forming a leak.
  • the water based adhesive spots in the array in some embodiments can be arranged in a staggered array such that adjacent adhesive spots in the columns of adhesive spots in the longitudinal direction overlap in the length direction and there are cross-hatched diagonal microchannels 104 (relative to the longitudinal direction) extending from the center channel to the edges that are devoid of SAP particles between the adhesive spots as shown in FIGS. 8, 9, and 12.
  • Such a configuration may be preferred since the fluid path to the edge is longer from the center channel 38 helping to mitigate leaks from the edge.
  • the pattern percentage coverage for the adhesive spots should be less than 100%.
  • too few adhesive spots results in insufficient SAP particle attachment and reduced capacity. Too much pattern percentage, even with microchannels, can lead to gel blocking and closing of the microchannels. Therefore, the adhesive spot pattern coverage in various embodiments can be from 20%to 95%, or from 30%to 90%, or from 40%to 85%, or from 60%to 80%. In the Examples, a pattern coverage of approximately 70%was found to provide preferred results.
  • the uncoated longitudinal direction center channel 38 area is included in this calculation as an area devoid of adhesive spots.
  • for a base sheet sample size measuring 400 mm in the longitudinal direction and 105 mm in the cross-web direction there are preferably from 100 to 400, or 125 to 375, or 150 to 350 adhesive spots per 0.042 square meters. Or when converting to square meters, there are 2380 to 9524, or 2975 to 8925, or 3572 to 8330 adhesive spots per square meter.
  • SAP particles are drop coated onto the printed base sheet.
  • the SAP particles then adhere to the plurality of water-based adhesive spots. Excess SAP is removed using vacuum or the web is run though a vertical section or inverted to allow gravity to remove excess particles and recycled to be reapplied.
  • Suitable super absorbent polymer particles are known to those of skill in the art of personal care articles.
  • Suitable SAP particles can have a particle size range of 300 to 500 microns and a be applied at a rate of 100 to 400 gsm, or 150 to 350 gsm, or 200 to 250 gsm.
  • Suitabel SAP particles are available from Nippon Shokubai Co. under the trade designation “QAX-1808” or “W2080” ; from BASF under the trade designation “HYSORB N7059” ; from Sumitomo Seika under the trade designation “AQUA KEEP” ; and from Sanwet under the trade designation “IM-930” .
  • a longitudinal direction center channel 38 is located in the middle one third of the width of the base sheet and the center channel 38 has a channel width 40 between a first channel edge 42 in the machine direction and a second channel edge 44 in the machine direction.
  • the center channel need not be perfectly centered in the base sheet in the longitudinal direction.
  • the center channel 38 is void of the plurality of water-based adhesive spots 34 and the plurality of SAP particles 36.
  • the center channel allows for liquids to flow relatively unencumbered the length of the diaper core. It also acts as a “header” to feed liquid in the cross-web direction to the microchannels 104.
  • the center channel width is preferably from 2 to 25 mm, or from 5 to 20 mm.
  • the center channel is formed by longitudinal direction ultrasonic bond line (s) 200.
  • the lines may be continuous or intermittent (dashes) extending in the longitudinal direction. Areas within the center channel where there is a bond line 200 are hydrophobic while unsealed areas 210 in the center channel (between the bond lines) are hydrophilic as seen in FIG. 6.
  • three bond lines that are solid having a width from 1-2 mm wide and spaced apart equally are used.
  • the center channel comprises three longitudinal bond lines, a first bond line forming the first channel edge, a second bond line located at the channel middle, and a third bond line forming the second channel edge and unsealed hydrophilic areas are located between the bond lines as shown in FIG. 6.
  • the nonwoven cover sheet 40 is optionally adhered to the base sheet 12 by a layer of hotmelt adhesive filaments 48 applied over the top of the plurality of SAP particles 36 as seen in FIG. 7. It was determined in the Examples that the chemistry used for some of the water-based adhesive spots failed the Drop Test unless the optional hotmelt adhesive filaments were applied. Furthermore, it was determined that a water-based adhesive instead of the preferred hotmelt adhesive may not work to attach the cover sheet and help hold the SAP particles in place after being insulted by saline and subjected to the Drop Test.
  • the optional holt melt adhesive was unexpectantly found to work even though it is applied directly over the SAP particles and yet it does not encapsulate the SAP preventing fluid uptake.
  • the hot melt adhesive is applied as filaments or strands as seen in FIG. 7. The filaments can hold the SAP particles together both before and after swelling helping to prevent SAP particle migration and gel blocking.
  • the desired hot melt adhesive basis weight range for effective performance was 2 -15 gsm, preferably 3 -8 gsm, and most preferably 4 -5 gsm.
  • the adhesive strand thickness range for effective performance was 10 -30 microns; preferably 12 -20 microns; and most preferably 12 - 15 microns.
  • the improvement in utilizing a hot melt adhesive filament network in keeping the SAP “gel” in place was demonstrated by the Drop Test as specified in Test Method 1.
  • a non-contact spray coating technique was used for applying the hot melt adhesive by utilizing a hot die under air pressure as shown in FIG. 15.
  • the hot melt adhesive was sprayed directly on top of the SAP particles as filaments to hold and retain the SAP particles.
  • the hot melt adhesive was instead first applied to the nonwoven top sheet and then the top sheet laminated onto the SAP particles and base sheet, the SAP particles did not stay in place and failed the Drop Test. This confirmed the unexpected result of needing to apply the hot melt adhesive as filaments directly onto the SAP particles.
  • Suitable hot melt adhesives can include the following chemistries: styrenic polymer of styrene-butadiene polymer, rubber-based adhesives, and/or acrylic-based adhesives which can be obtained from Bostik, Henkel, and H. B. Fuller.
  • the nonwoven cover sheet helps to contain the SAP particles and is preferably highly permeable and soft to the touch.
  • the nonwovens are often referred to as air-through nonwovens having good air permeability.
  • Another suitable cover sheet can include a two-layer spunbond-spunbond nonwoven. Suitable nonwovens can have a basis weight from 20 to 80 gsm, or from 30 to 50 gsm.
  • the first edge 30 and the second edge 32 are ultrasonically sealed to help prevent SAP particle leakage, liquid leakage, and to attach the cover sheet to the base sheet.
  • a 2 mm wide bond seal was placed 2 mm inboard from the outer edge was used.
  • Other suitable seals can be employed and there can be more than one seal line used and the widths of the seal lines can be varied.
  • the seal strength should be sufficient such that a soiled diaper core does not come apart at the seam.
  • An SMS base sheet is unwound 50 and screen printed 52 with a plurality of water-based adhesive spots.
  • SAP is drop coated 54 onto the adhesive spots forming SAP islands and excess SAP is removed by a vacuum system (not shown) .
  • Hot melt adhesive is applied as filaments 56 to the SAP islands and a nonwoven cover sheet is unwound 58 and brought into contact with the hotmelt adhesive and the SAP islands.
  • the laminated diaper core is ultrasonically welded 60 and has a plurality of ultrasonic bond lines 50 positioned along the first edge 30, the second edge 32, the first channel edge 42, and the second channel edge 44 of the diaper core 10.
  • the finished diaper core is then wound into a roll 62 for shipping.
  • a testing liquid consisting of a 9 g/l solution of sodium chloride in distilled water with a surface tension of (70 +/-2) mN/m was made.
  • One liter (1000 grams) of distilled water was weighed and put into a container.
  • 9.0 grams of sodium chloride and 0.1 grams of Sensient FD&C Blue No. 1 Powder were weighed and then added to the premeasured 1 liter of distilled water in container.
  • a magnetic stirring bar was then added into the solution and the solution stirred on a magnetic stirrer for 15 minutes.
  • the test sample was placed onto a flat surface and the insult cylinder test apparatus (77 mm tall, 50 mm circumference, weighing 80 grams and constructed from PVC pipe) was gently placed on the center of the dried adhesive/SAP test sample. 75 grams of Saline Solution was weighed into a beaker and then poured into the opening of the test apparatus in a swift motion (trying to dispense in under 3 seconds) . The test apparatus was then removed once all the Saline Solution was absorbed by the test sample. The test sample was then left undisturbed to sit for 40 minutes before testing.
  • the insult cylinder test apparatus 77 mm tall, 50 mm circumference, weighing 80 grams and constructed from PVC pipe
  • the drop test apparatus 300 as shown in FIG. 16 was used to drop the absorbent core a known distance while attached to a rod.
  • the apparatus was approximately 53 cm high and suspended a drop rod on two horizontal support arms at a height of 52.4 cm from a horizontal surface.
  • the support arms were spaced apart approximately 38.7 cm from outside edge to outside edge. Beneath the support arms where a pair of longer impact arms spaced apart approximately 38.7 cm that would catch and hold the drop rod after being released.
  • the impact arms were spaced lower 13.0 cm vertically (top of support arm to top of impact arm) from the support arms.
  • the drop bar was 1 cm in diameter, 41.5 cm in length, weighed 149.5 grams and was made from aluminum.
  • One method to build the test apparatus is to use 80/20 T-slot available from Aluminum Building System (Grainger, Bloomington, MN) .
  • the diaper core test samples were attached to the drop rod with two binder clips measuring 5 cm wide and weighing about 25.2 grams that clipped the diaper core to the drop bar.
  • the drop rod was rested on the upper support arms of the drop test equipment.
  • one end of diaper core test sample was wound around the drop rod such that the free end touched or almost touched the body of the diaper core and was clipped to the drop rod by placing the two binder clips to hold in place as shown.
  • the diaper core should be clipped to the drop rod such that the center channel is vertical.
  • the test sample on the drop rod was slightly lifted off the support arms (no more than 13 mm) , moved forward, and then released while approximately horizontal such that it fell and struck both of the lower impact arms of the test apparatus (total drop height of 13 cm) and came to a rest on the impact arms. No additional force was introduced to the test sample as it was dropped. This action counted as 1 drop. The action was repeated until diaper core failure or until the diaper core passed 10 drops onto the support arms.
  • Test samples were dropped up to ten times or until observed failure. Failure was defined as 50%or more of the “gelled” SAP falling off of the base adhesive/nonwoven layer prior to 10 drops. Success was defined as 51%or more of the “gelled” SAP or more adhering to the base adhesive/nonwoven layer after 10 drops.
  • the absorbent core test sample was placed on a flat surface.
  • the center of the test sample from the ends and sides was measured and marked with a small center dot.
  • the insult cylinder test apparatus as used in Test Method 1 was placed in the center of the test diaper core concentric with the center dot.
  • the Saline Solution was weighed out into a beaker in an amount based on test sample area and poured into the opening of the test apparatus in a swift motion (trying to dispense entire liquid amount in under 3 seconds) .
  • a stopwatch was started as soon as pouring began.
  • the stopwatch was stopped as soon as all of the Saline Solution was observed absorbed through the top sheet of test sample.
  • the 1 st Strike Through time was recorded.
  • the stopwatch was started immediately to allow for total liquid and after 10 minutes the insult cylinder test apparatus was then removed. The distance the fluid traveled was measured in the length and width direction of absorbent test sample from the center dot without disturbing test sample. The distance was recorded in mm. After 10 minutes, the insult cylinder test apparatus was again placed concentric with the center dot on the previous insult location. The Saline Solution amount was weighed out into a beaker based on test sample area and poured into the opening of the test apparatus in a swift motion (trying to dispense entire liquid amount in under 3 seconds) . The stopwatch was started as soon as pouring began. The stopwatch was stopped as soon as all of the Saline Solution was absorbed through the top sheet of test sample. The 2 nd Strike Through time was recorded. The stopwatch was started immediately and kept running for 5 minutes. The insult cylinder test apparatus was removed. The distance the fluid traveled was measured in the length and width direction from the center dot without disturbing test sample after the 5 minutes. Distance in mm was recorded.
  • Test Method 3 Strike Through and Fluid Traveled Tests Using a U-Shaped Test Apparatus
  • the test apparatus 400 for the U-shape Strike Through and Fluid Travel Tests is shown in FIG. 17.
  • Plexiglass (3 mm thick) was shaped in the form of a U with the legs of the U spaced about 305 mm apart and the depth of the U about 225 mm and the width of the U about 210 mm and having a top cover.
  • Fastener hook strips (25 mm by 152 mm) , obtained from 3M Company, St. Paul, MN, under the trade designation "3M HOOK CHK-00732" , were adhered to the U to hold the ends of the diaper core and to hold the edges of the diaper core near the middle where they would tend to wrap the legs of a wearer to anchor diaper core to the test apparatus.
  • a 25.4 mm hole was placed 27 cm from one edge of apparatus (approximate center) into the top cover for fluid to “insult” diaper core.
  • Standard 19.1 mm inside diameter tubing was threaded through the hole and sealed with Multipurpose RTV Silicon Sealant, obtained from Grainger, Bloomington, MN.
  • the tubing was 23 cm in length and reached from the bottom of the U to the top hole and slightly through opening in the top plate for sealing purpose.
  • the Saline Solution amount was weighed into a beaker based on test sample area and poured into the opening of the funnel in a swift motion (trying to dispense entire liquid amount in under 3 seconds) .
  • a stopwatch was started and watched as the insult liquid entered the absorbent core. The stopwatch was stopped after all liquid entered the core and the time recorded (in seconds) for the Saline Solution to be completely absorbed. The 1 st Strike Through time was recorded. After 5 minutes, the distance that the fluid traveled as the diaper core was held by the U-shaped support against the force of gravity was measured with a tape measure. Distance was recorded in mm. The stopwatch was kept running for 10 minutes. Repeat above procedure when testing a 2 nd, strike through time.
  • Adhesive Example Number 6 with a Tackifier Adhesive Example Number 6 with a Tackifier:
  • Example 6 100 grams of BASF ACRONAL A220NA was measured into a jar and then 20 grams of LAWTER’s SNOWTACK SE724G was added to the same jar. This solution was then stirred under 300 rpm with a 3-blade mixer for 5 minutes before use. The solution was then used for coating and testing in Example 6.
  • a one-inch-wide masking tape obtained under the trade designation “SCOTCH 232” , from 3M Company, St. Paul, MN, was used to secure the top and bottom of the base SMS nonwoven down onto a flat surface so the test sample did not move during Mayer Drawdown coating.
  • SCOTCH 232 Mayer Drawdown Rod
  • With a number 4 Mayer Drawdown Rod (BYK-Gardner, Columbia, MD) about 6 mL of the adhesive, as received from manufacturer or as made per described method above, was placed to the top middle portion of the SMS nonwoven using a 3 mL disposable pipette. The Meyer Rod was then pulled across the nonwoven at a constant speed to coat the nonwoven. The Meyer Rod was then placed in a container of water for cleaning.
  • Example 17 the diaper core was produced on a machine having the process steps as shown in Figure 15.
  • a sample of SMS nonwoven was cut 150 mm wide by 450 mm long.
  • the top and bottom of the nonwoven was taped down onto the flat surface such that the sample did not move during adhesive screen coating.
  • the printing screen was then placed on the top of the nonwoven, with the center of the screen overlapping with the center of the bottom nonwoven.
  • the screen 500 mm in width, 910 mm in length and 10 mm in thickness
  • the patterned section of the screen had a mesh size of 40 while the rest of the screen had no such mesh to direct the adhesive to penetrate through the areas with the mesh.
  • a metal/rubber hybrid plate (metal part on the top: 55 mm in height, 35 mm in width and 300 mm in length; rubber part on the bottom in contact with the screen during adhesive coating: 60 mm in height, 10 mm in width and 300 mm in length) was used to apply manual pressure of approximately 0.05 MPa by pushing around 10 g of BASF Acronal 220na adhesive on the top of the screen to penetrate through the mesh and deposit onto the hydrophilic side of the SMS nonwoven.
  • the metal plate was pulled in the longitudinal direction of the screen at a constant speed to print the adhesive on the SMS nonwoven.
  • Within 30 seconds of coating the adhesive about 30 grams of SAP was applied onto the entire sample of wet adhesive in such a way that the entire sample was coated evenly.
  • the sample was then allowed to sit for 2 minutes, and excess SAP particles were removed by holding the sample in a vertical position and gently shaking by moving hands back and forth horizontally about 2.54 cm while gripping the sample until no more SAP particles fell off.
  • the air-through nonwoven was placed on the top of the SAP layer to cover the SAP particles and then the sample was cut to 400 mm in length which covered the whole SAP patterned area of the nonwoven. MD tunnels (if any) and edge lines were drawn on the top of the air-through nonwoven and then the lines welded with an ultrasonic welder at power level of 10 (US-004 Sewfree Ultrasonic Multi-Purpose Welder, H&H, Hong Kong) .
  • the center channel was centered in the top nonwoven layer and created by using heat bonding or ultrasonic welding.
  • the base sheet nonwoven used was a blend of layers (hydrophilic on top and hydrophobic on bottom) .
  • the layers were melted together to create a hydrophobic weld line.
  • center channel welded area had hydrophobic and hydrophilic regions alternating alternately across the width of the center channel, depending on how many weld lines were used and how they were spaced in the cross-web direction.
  • the diaper core was made by hand and followed the procedure under examples 1-16.
  • the diaper core was produced on a machine having the process steps as shown in Figure 15.
  • the diaper core material in endless form was ultrasonically welded with an ultrasonic welder machine (obtained from Emerson, St. Louise, MO, under the trade designation “BRANSON 900 SERIES” ) .
  • the ultrasonic welder machine was a 20 Khz ultrasonic welder machine equipped with an 11.4 cm x 15.2 cm (4.5” x 6” ) aluminum block horn and booster of 1: 1.5.
  • the weld method was Energy with a weld value of 700 J, at a pressure of 1379 kPa (200 psi) for a 7.62 cm (3 inch) circle with fabricated weld lines. Amplitude was set to 50%, line speed set at 12 feet per minute.
  • absorbent core samples were cut to the size of 115 mm by 400 mm and then the insulted side of absorbent article was placed onto reclosable fastener hooks, obtained from 3M Company, St. Paul, MN, under the trade designation "3M HOOK CHK-00732" , following the shape of the U. The sample was then placed securely tight up against the plexiglass.
  • Comparative 1 was the inner diaper core removed from a Care Daily diaper size L (baby weight of 9-14 kg) .
  • the sample preparation of the flat-sample test was very similar to that of the U-shape test above. The major difference was that the flat-sample test did not use the U-shape test apparatus. Instead, all the liquid was insulted with the sample laid flat on a table. Samples with one longitudinal bond line and three longitudinal bond lines were compared with a sample without any center channel. From the test results below, the introduction of the center channel demonstrated its utility of directing the liquid flow, resulting in shorter Strike Through Time and longer liquid travel length.
  • the desired adhesive basis weight range was 2-15 gsm; preferably in the range of 3-8 gsm; and most preferably in the range of 4-5 gsm.
  • Adhesive strand thickness range was 10-30 microns; preferably in the range of 12-20 microns; most preferably in the range of 12-15 microns.
  • the improvement of the hot melt adhesive network keeping the SAP “gel” in place was demonstrated by the Drop Test specified in Test Method 1.
  • a non-contact spray coating technique was used for applying the hot melt adhesive by utilizing a hot die under air pressure as shown in FIG. 15.
  • the hot melt adhesive was sprayed directly on top of the SAP particles as filaments to hold and retain the swelled SAP particles.
  • the hot melt adhesive is sprayed in filaments or thin strands that form a network or web-like structure on the nonwoven top sheet layer.
  • SBR styrene-butadiene-copolymer rubbers
  • the Tg should be low-preferably below -20 degrees Celsius, or below -15 degrees Celsius.
  • the SBR should be listed as carboxylated, containing some carboxylation of some type introduced into the polymer to add some acid groups and polarity.
  • a cationic and Silane containing emulsion was used.
  • the cationic group likely interacts with the acid groups of the SAP and the silane containing group will react to form a covalent bond with the acid groups in the SAP.
  • the U shape test apparatus shows that the center channel provides some upward fluid flow when compared to no “open middle” area (ex. 28) or no middle area at all (comparative 1) .
  • the center channel number of lines shows an increase in fluid flow in the longitudinal direction.

Landscapes

  • Health & Medical Sciences (AREA)
  • Epidemiology (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Vascular Medicine (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Absorbent Articles And Supports Therefor (AREA)

Abstract

Selon l'invention, une partie centrale de couche (10) comprend : une feuille de base non tissée (12) qui présente un premier côté hydrophile (16) et un second côté hydrophobe (20) opposé, la feuille de base (12) présentant un premier bord (30) dans la direction longitudinale et un second bord opposé (32) dans la direction longitudinale ; une pluralité de petites zones adhésives à base d'eau (34) situées sur le premier côté (16) et une pluralité de particules SAP (26) adhérant au premier côté (16) par l'intermédiaire des petites zones adhésives à base d'eau (34) ; un canal central longitudinal (38) situé au milieu d'un tiers de la largeur de la feuille de base (12), le canal central (38) étant dépourvu de petites zones adhésives à base d'eau (34) et de particules SAP (26) ; une feuille de recouvrement non tissée (46) positionnée sur la pluralité de petites zones adhésives à base d'eau (34) et la pluralité de particules SAP (26) ; la feuille de recouvrement non tissée (46) étant stratifiée sur la feuille de base (12) par une pluralité de liaisons ultrasonores (50) positionnées le long des bords longitudinaux (30, 32) de la feuille de base (12). La partie centrale de couche (10) permet d'éviter les blocages de gel et d'obtenir une excellente absorption des excréments humains.
PCT/CN2022/082954 2022-03-25 2022-03-25 Partie centrale de couche WO2023178636A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2022/082954 WO2023178636A1 (fr) 2022-03-25 2022-03-25 Partie centrale de couche

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2022/082954 WO2023178636A1 (fr) 2022-03-25 2022-03-25 Partie centrale de couche

Publications (1)

Publication Number Publication Date
WO2023178636A1 true WO2023178636A1 (fr) 2023-09-28

Family

ID=88099546

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/082954 WO2023178636A1 (fr) 2022-03-25 2022-03-25 Partie centrale de couche

Country Status (1)

Country Link
WO (1) WO2023178636A1 (fr)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2004201A (en) * 1977-09-13 1979-03-28 Beghin Say Sa Coated absorbent structures
EP0463716A2 (fr) * 1990-04-20 1992-01-02 James River Corporation Composé absorbant et procédé pour sa fabrication
US6790798B1 (en) * 1999-09-29 2004-09-14 Japan Absorbent Technology Institute Highly water absorbent sheet
WO2006075341A1 (fr) * 2005-01-12 2006-07-20 Fintex & Partners Italia S.P.A. Materiau composite absorbant avec agents de liaison hydrosolubles, produits obtenus a partir dudit materiau et procede de fabrication
US20090018517A1 (en) * 2007-07-11 2009-01-15 Riccardo Cecconi Composite absorbent material with water-soluble bonding agents, products made of said material nad method for its manufacture
CN105147462A (zh) * 2006-02-22 2015-12-16 德科技控股有限公司 制备吸收复合材料的方法和利用吸收复合材料的吸收制品
CN105816277A (zh) * 2011-06-10 2016-08-03 宝洁公司 一次性尿布
CN106214354A (zh) * 2016-09-14 2016-12-14 天津市中科健新材料技术有限公司 一种复合吸水纸
US20170029649A1 (en) * 2014-04-10 2017-02-02 3M Innovative Properties Company Adhesion promoting and/or dust suppression coating

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2004201A (en) * 1977-09-13 1979-03-28 Beghin Say Sa Coated absorbent structures
EP0463716A2 (fr) * 1990-04-20 1992-01-02 James River Corporation Composé absorbant et procédé pour sa fabrication
US6790798B1 (en) * 1999-09-29 2004-09-14 Japan Absorbent Technology Institute Highly water absorbent sheet
WO2006075341A1 (fr) * 2005-01-12 2006-07-20 Fintex & Partners Italia S.P.A. Materiau composite absorbant avec agents de liaison hydrosolubles, produits obtenus a partir dudit materiau et procede de fabrication
CN105147462A (zh) * 2006-02-22 2015-12-16 德科技控股有限公司 制备吸收复合材料的方法和利用吸收复合材料的吸收制品
CN106580559A (zh) * 2006-02-22 2017-04-26 德科技控股有限公司 制备吸收复合材料的方法和利用吸收复合材料的吸收制品
US20090018517A1 (en) * 2007-07-11 2009-01-15 Riccardo Cecconi Composite absorbent material with water-soluble bonding agents, products made of said material nad method for its manufacture
CN105816277A (zh) * 2011-06-10 2016-08-03 宝洁公司 一次性尿布
US20170029649A1 (en) * 2014-04-10 2017-02-02 3M Innovative Properties Company Adhesion promoting and/or dust suppression coating
CN106214354A (zh) * 2016-09-14 2016-12-14 天津市中科健新材料技术有限公司 一种复合吸水纸

Similar Documents

Publication Publication Date Title
US5938650A (en) Absorbent core for absorbing body liquids and method
US10772769B2 (en) Method and apparatus for producing composite structure
TWI494136B (zh) Absorbent sheet structure
EP3292849B1 (fr) Procédé et appareil de fabrication d'une structure composite
CA1285366C (fr) Revetement pelliculaire ajoure, et sa fabrication
JP4995082B2 (ja) 吸収性コア構造体の製造方法
US10123920B2 (en) Absorbent article having asymmetric absorbent core component
EP1782784B1 (fr) Absorbeur et article absorbant
BR112015010854B1 (pt) Artigo absorvente
WO1996006590A1 (fr) Article absorbant les liquides
BR112013030593B1 (pt) estrutura absorvente para artigos absorventes
JP2003290290A (ja) 吸収体、その製造方法およびそれを用いた吸収性物品
US7608748B2 (en) Absorbent sanitary product
JP4902862B2 (ja) 吸収性衛生製品
WO2023178636A1 (fr) Partie centrale de couche
KR19990083069A (ko) 일회용 체액 흡수성 물품
WO2008072433A1 (fr) Article absorbant
JP2009514642A (ja) 吸収性物品用の剥離可能な不織布包装体
EP1465519B1 (fr) Article absorbant jetable
JPH0538350A (ja) 吸収性物品
JPH04129553A (ja) 吸収性物品の表面材及びその製造方法
JPH09272170A (ja) バックシート基材およびその製造方法
JPH03234617A (ja) 高吸水性シート
JP4601963B2 (ja) 吸収物品のためのインサート

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22932700

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 22932700

Country of ref document: EP

Kind code of ref document: A1