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
  • A61F2013/530131—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 being made in fibre but being not pulp
  • A61F2013/530335—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 being made in fibre but being not pulp being in peat moss
• • 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
  • A61F2013/530583—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 characterized by the form
• • 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
  • A61F2013/530868—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 liquid distribution or transport means other than wicking layer
  • A61F2013/530897—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 liquid distribution or transport means other than wicking layer having capillary means, e.g. pore or fibre size gradient

Definitions

• An absorbent structure that has poor wicking properties usually increases the likelihood of failure of the absorbent product to hold and contain body liquids.
• Body exudate will be localized to a certain area of the poorly wicking absorbent medium, causing localized saturation whereby excess liquid may overflow through an external surface of the absorbent product. This overflow may contact the user's garment and cause stains or contact the user's body and cause wet discomfort or rash.
• the improved wicking properties of such an absorbent core provide the capacity for liquids to travel by capillary pressure throughout the entire absorbent volume.
• the wicking properties of the above-described sphagnum moss sheet provide the ability for the sheet to be highly absorbent while remaining relatively thin.
• the present invention provides a liquid-absorbent article comprising absorbent particulate material and further comprising first and second zones in intimate fluid communicative relationship, each zone having a multiplicity of inter-particle and intra-particle interstices admitting passage of liquid, said first zone having a larger average interstice size than said second zone, whereby said second zone manifests a higher capillary attraction than said first zone.
• the terminology "particle” shall mean fibrous as well as non-fibrous materials, i.e., any small unit of material without limitations of shape.
• a fiber that is characterized as having a geometrical extension along a preferential direction will be considered a particle.
• "particulate material” includes materials made of fibers, particles having non-fibrous identity, or a combination of both.
• inter-particle interstices refers solely to the interstices defined between the particles, while “intra-particle interstices” refers to an open cellular structure inside the particles, such as the lumen in sphagnum moss leaves.
• average interstice size refers to both the intra-particle interstices and the inter-particle interstices.
• intimate fluid-communicative relationship refers to a condition in which liquid in one of the zones can easily migrate toward the other zone. This condition is achieved when the zones are co-formed or when they have been formed as discrete elements and then joined to one another by means to create an interface providing a path of comparatively low resistance to the migration of liquid. Suitable means for joining the zones include, but are not limited to, adhesive, thermobonding, needle punching, and the like, and combinations thereof.
• A) adjusting the proportion between inter-particle interstices and intra-particle interstices in the liquid-absorbent material For example, an increase in the relative amount of particles having intra-particle interstices in the liquid-absorbent material, wherein the intra-particle interstices are smaller than the inter-particle interstices, will cause the average interstice size of the liquid-absorbent material to diminish.
• sphagnum moss has lumen (i.e. intra-particle interstice) whose average size is typically below 66 microns. Accordingly, a relative increase in the amount of sphagnum moss in the liquid-absorbent material will result in a reduction in the average interstice size. Conversely, a relative decrease in the ratio intra-particle interstices/inter-particle interstices, results in an increase in the average interstice size.
• the size of inter-particle interstices of the material is proportional to the size of the particles.
• the incorporation of coarse particles into a liquid- absorbent material will result in a liquid-absorbent article having larger interstices than would be obtained by the use of fine particles.
• This allows one to regulate the average interstice size by varying the average particle size of the material.
• the average interstice size of a material may be increased by introducing in the absorbent material non-porous particles that are relatively large. The non-porous character of the particles increases the ratio inter-particle interstices/intra-particles interstices while the coarseness of the particles augments the average inter- particle size.
• any of the steps A to D applied alone or in combination can be used to control the average interstice size of individual zones of the liquid-absorbent to optimize the porosity gradient in the liquid-absorbent product.
• the porosity gradient is obtained by forming the various layers of the liquid-absorbent sheet from sphagnum moss particles having different dimensions. More particularly, the upper layer is formed of sphagnum moss particles that are relatively coarse i.e. larger than the particles in the lower layer. When those particles are amalgamated together during the formation process of the absorbent sheet, large inter-particle interstices remain between them. In contrast, the lower layer is formed primarily of fine sphagnum moss particles that, due to their smaller size, fit closer to one another to provide inter-particle interstices of lesser dimensions.
• a hybrid structure combining the features of the two previously described embodiments is the most preferred.
• the characterizing feature of this variant is the inclusion of debonding component into the upper laver of coarse sphagnum moss particles.
• the debonding component may be a chemical agent or a physical separator such as cross-linked fibers.
• the layer of coarse sphagnum moss particles has a particle size median value in the range from about 2000 microns to about 500 microns.
• the fine layer of sphagnum moss particles has a particle size median value in the range from about 500 microns to about 150 microns.
• the coarse layer of sphagnum moss has at least about 55% of inter-particle interstices (in term of interstice count rather than interstice volume) having a size in the range from about 600 microns to about 120 microns, more preferably at least about 60% of inter-particle interstices in that range and most preferably at least about 63% of inter-particle interstices in that range.
• the co-forming process broadly described above greatly simplifies the manufacture of the liquid-absorbent article in accordance with the invention because the formation and bonding of the layers is accomplished in a single operation.
• a further advantage of this method resides in the strength of the bond between the layers which is highly resistant to delamination. As a result, the liquid-absorbent article can withstand vigorous mechanical working without loosing its structural integrity. Further, the bond is such as to establish the desirable intimate fluid-communicative relationship allowing fluid to easily migrate from the upper layer towards the lower layer.
• the manufacturing process begins by preparing a mother slurry containing sphagnum moss particles of varying sizes. The slurry is then subjected to a classification step to separate the mother slurry in at least two slurry fractions according to the size of the sphagnum moss particles. The slurry fractions are then laid in a superposed relationship on a Fourdrinier wire as described above.
• the sphagnum moss particle separation is followed by the addition of debonding component in the slurry fraction containing the coarse sphagnum moss particles.
• the manufacture of the liquid absorbent article conducted by assembling together discrete absorbent layers is perhaps less desirable than the integral formation approach, primarily because additional manipulations are required to complete the manufacture of the absorbent article.
• the interface between the discrete layers provides a liquid path of somewhat higher resistance than when the layers are integrally formed. Still, this embodiment exhibits significantly improved liquid-absorbent properties by comparison to prior art structures and it thus suitable for many applications.
• the invention further provides a method for manufacturing a laminated liquid-absorbent article, comprising the steps of:
• the liquid communicative relationship between the absorbent layers is created by co-formation, such as wet laying the slurry fractions in a superposed relationship, as described earlier.
• This approach produces an integrally formed liquid-absorbent article.
• the absorbent layers may be formed separately from one another and then assembled by adhesive bonding or the like to establish the liquid-communicative relationship between them.
• FIG. 1 is a fragmentary, perspective view of a sanitary napkin incorporating the liquid-absorbent article according to the invention:
• FIG. 2 is a fragmentary perspective view of the liquid-absorbent article according to the present invention that is characterized by a non-uniform porosity distribution;
• FIG. 5 is a flowchart of the process for manufacturing the liquid-absorbent article in accordance with a variant
• the structure of the absorbent component 56 is shown in Figure 2. It comprises a central core 58 containing primarily sphagnum moss and having a porosity gradient along the Z direction (the thickness).
• the central core 58 is constituted by an upper layer 60a and a lower layer 60b intermixed at the interface to provide an intimate liquid-communicative relationship between them.
• Layer 60a has a larger average interstice size than layer 60b.
• Headboxes 32, 34, 66 and 36 arranged in a spaced apart relationship along the path of travel of the wire 26 are provided to lay on the wire 26 slurry in sheeted form.
• the headbox bank deposits on the wire 26 four (4) layers of slurry in a superposed relationship to form a laminated slurry web. More specifically, the headboxes 34 and 66 lay slurries containing sphagnum moss while the headboxes 32 and 36 deliver slurries of fibrous material such as Kraft wood pulp or any other suitable substance.
• the preparation of the sphagnum moss slurry layers supplied to headboxes 34 and 66 is illustrated by the flowchart of Figure 4.
• the centrifugal classifier 74 is calibrated to produce a reject stream having a particle size median in the range from about 2000 microns (10 mesh) to about 500 microns (35 mesh) that is directed at headbox 66.
• the particle size median value is defined as the size of the particles having the highest frequency when the sphagnum moss particles are classified according to size.
• a fibrous component such as polyester fibers and/or Kraft wood pulp at step 76 prior to supplying the slurry to headbox 66 that forms the layer 60a of the central core 58.
• Suitable fibrous components may include such materials as Kraft wood pulp, cross-linked cellulosic fibers, mechanical wood pulp, natural or synthetic textile fibers such as rayon, polyester, nylon, acrylic and the like, and mixtures thereof.
• the fibrous components are generally added to the headbox in an amount from 2 to 20% by weight of the absorbent sheet 10, preferably from 2% to 6%.
• mechanical wood pulp is meant to include ground wood pulp, thermo-mechanical pulp and refiner wood pulp.
• the Kraft wood pulp also usable in combination with sphagnum moss, is essentially chemically treated, long fibred wood pulp such as sulphite and sulphate wood pulps.
• a debonding component is added to the slurry supplied to headbox 66 in an amount which is effective to increase the inter-particle interstices in the liquid-absorbent product.
• Suitable debonding agents include, but are not limited to fibrous materials which are effective for reducing the cohesiveness of the particles in the liquid-absorbent product. These fibrous materials preferably have a length of from about 0.6 cm to about 1.9 cm, preferably about 1.3 cm and a denier of from about 1.0 to 5.0.
• Preferred debonding components which have been found to be particularly effective in opening-up a sphagnum moss network in order to allow a faster liquid acquisition are cross-linked cellulosic fibers.
• the accepts stream of the centrifugal classifier 74 that contains sphagnum moss particles of smaller size is supplied to a 60 mesh stationary screen 78 of the type described in Canadian patent application 2,057,654 assigned to Johnson & Johnson Inc. laid open on June 14, 1993 which is incorporated herein by reference in its entirety.
• the screen 78 features a system of jets directed at the screen plate to prevent the screen apertures from clogging.
• the rejects stream that contains particles larger than about 150 microns (100 mesh) are discarded.
• the accepts having an average particle size in the range from about 500 microns (35 mesh) to about 150 microns (100 mesh) are directed to headbox 34 to form layer 60b of the central core 58.
• a stationary screen operating on the principle of a sieve be used in the second stage 78 than a centrifugal classifier because it allows a better process control.
• a stationary screen may be substituted to the centrifugal classifier 74.
• Such stationary screen is identical to screen 78 described above with the exception that screening apertures of 6.35 mm could be used rather than 60 mesh perforations.
• the slurry fractions supplied to the headboxes 34 and 66 are prepared on the production line illustrated in Figure 5.
• the difference with the set-up of Figure 4 resides in that no cross-linked cellulosic fibers are added to the flow of coarse sphagnum moss particles.
• no separation of the sphagnum moss particles is made.
• the slurry from the screening system 68 and 70 is split in two parts having approximately the same sphagnum moss particle size distribution.
• cross- linked fibers or another debonding component is added to one of the slurry fractions from which the layer 60a is made.
• the headbox 66 delivers the slurry fraction of coarse sphagnum moss particles intermixed with cellulosic cross-linked fibers.
• This slurry fraction has a consistency of 0.5% by weight of solids, a flow rate to deliver 182 grams of solids per square meter on the wire 20.
• the coarse particles slurry contains sphagnum moss in the range from about 20% to 60% by weight of solids in the slurry, cross-linked cellulosic fibers in the range from about 5% to about 75% by weight and polyester fibers up to 20% by weight.
• the layer 60a (coarse sphagnum particles) had a significant amount of interstices in the size range from about 600 microns to about 120 microns.
• layer 60a should have at least about 50% of interstices in the range 600 - 120 microns, more preferably at least about 60% and most preferably (in the embodiment shown) at least about 63%.
• the layer 60b had less interstices in this size range (41% in the embodiment shown).
• a second example of a formulation for the sphagnum moss slurry layers delivered from the headboxes 34 and 66 is as follows.
• This formulation was prepared in accordance with the manufacturing process shown in Figure 5 and contained sphagnum moss in the range from about 68% to 100% by weight of solids in the slurry, polyester fibers up to 20% by weight and Kraft wood pulp fibers up to 30% by weight.
• the slurry fractions coarse/fine differed primarily by the particle size of the sphagnum moss material.
• the slurry fraction of primarily fine sphagnum moss particles was as follows:
• the slurry fraction of primarily coarse sphagnum moss particles was as follows :
• a third example of a formulation for the sphagnum moss slurry layers delivered from the headboxes 34 and 66 is as follows. This formulation was prepared in accordance with the manufacturing process shown in Figure 6. In this example, both slurry fractions have approximately the same sphagnum moss particle size distribution.
• the lower slurry layer delivered from the headbox 34 had a sphagnum moss content in the range from about 80% to 100% by weight of solids in the slurry and contained polyester fibers up to 20% by weight.
• the specific formulation is as follows:
• the upper slurry fraction delivered from the headbox 66 contains sphagnum moss in the range from about 20% to about 60% by weight of solids in the slurry, cross-linked cellulosic fibers in the range from about 5% to about 75% by weight and polyester fibers up to 20% by weight.
• sphagnum moss in the range from about 20% to about 60% by weight of solids in the slurry, cross-linked cellulosic fibers in the range from about 5% to about 75% by weight and polyester fibers up to 20% by weight.
• a final Kraft wood pulp slurry layer was laid from the headbox 36 on the sphagnum moss slurry in order to form the reinforcing top layer 62.
• This final layer was identical in terms of consistency and composition to the bottom Kraft wood pulp layer 64 previously deposited except that the flow rate was such as to deposit on a square meter of the wire 26 five grams of solids.
• the web leaving the dewatering station 50 passed through a drier 52 whose purpose was to elevate the temperature of the web to evaporate residual water.
• the drier 52 is of a
• a calendering station 54 Downstream of the drier 52 a calendering station 54 is provided which mechanically compresses the dried product in order to densify the sphagnum moss material for enhancing Its drying power. If desired, the calendering station 54 may be followed by a perf-embossing station (not shown in the
• micro-corrugating operation which is similar to the
• liquid-absorbent structure is solely subjected to an embossing operation to create closely spaced hinge lines.
• the absorbent article under the second embodiment may be treated with re-wetting agent.
• re-wetting agent Preferably, an RL Thorowet re-wetting agent (available from Clough
• a G-60 Thorowet re-wetting agent available from Clough Chemicals
• Clough Chemicals is delivered on the Kraft /Sphagnum/ Sphagnum/Kraft laminated slurry layers, prior the dewatering stage in an amount of 0.8% by weight of solids in the absorbent article.
• the G-60 Thorowet re-wetting agent is delivered on the top Kraft layer in a foamed condition, as described in the Canadian Patent
• FIG 7. A variant of the liquid-absorbent article is illustrated in Figure 7.
• This variant is characterized in that the layers 60a and 60b are formed as discrete entities and then united to form a compound liquid-absorbent structure, rather than being integrally formed.
• the layers are manufactured by following the process steps illustrated in Figure 4 with the exception that headboxes 34 and 66 deposit the fine and the coarse slurry fractions on separate Fourdrinier wires (not shown in the drawings). Each slurry fraction is then subjected to independent post-format ion treatments, such as pressing, drying, calendering, etc.
• the resulting absorbent layers are then united to one another in a superposed relationship by adhesive or any other suitable agency.
• Sanitary napkins constructed with the liquid-absorbent article 56 as the absorbent core are found to possess a very high liquid-absorption capacity and a comparatively high liquid-penetration rate which reduces the risk of failure when a large quantity of body exudate is suddenly released on the sanitary napkin.
• the control is an integrally formed sheet containing a central core of sphagnum moss having a uniform porosity distribution and united to two outer layers of Kraft wood pulp.
• the central core contains 76.92% by weight of solids in the control sheet of sphagnum moss, 3.69% of polyester fibers and 7.38% of Kraft wood pulp.
• Each of the top and bottom Kraft layers represent 4.61% of the control by weight of solids.
• the control sheet also contains 0.92% by weight of solids of G-60 Thorowet re-wetting agent and 0.4% by weight of solids of RL Thorowet re-wetting agent that are applied as discussed earlier.
• the basis weight of the control sheet is of 325 grams per meter squared.
• the sanitary napkin control is manufactured by placing on the absorbent article as described above cut in the form of a 10 centimeter (cm) by 10 cm square, a transfer layer of identical dimensions.
• the specific transfer layer used has a basis weight of 120 grams per meter squared and it is
• Airtex 397 a 10 cm by 10 cm embossed hydrophillic apertured film is placed over the transfer layer.
• the apertured film is known in the trade as wettable Reticulon and it is used to manufacture the cover layer of a sanitary napkin commercialized by Johnson & Johnson in Germany under the trademark Silhouette Ultra.
• Purpose to determine the absorption capacity of an absorbent material.
• Test procedure a disk of 90 mm diameter is cut from a sheet of the material to be tested. The dry weight of the disk is measured and recorded. The disk is deposited on the porous plate of a GATS (Gravimetric Absorbency Test System)
• test fluid is allowed to ingress the sample through the porous plate for a period of 15 minutes.
• the wetted sample is removed from the porous plate and weighted to determine the amount of test fluid uptake.
• the absorption capacity is expressed in terms of volume of fluid absorbed (cubic centimeters (cc) or mllliliters (ml)) per gram of absorbent material. For ease of reference, however, the absorption capacity is reported in the above test results in mllliliters per pad of absorbent material in the form of a sheet of 20 cm X 5 cm having a weight of 4 grams (g).
• Test fluid 1% NaCl solution
• Test procedure the instrument disclosed in the US patent 5,361,627 assigned to Johnson & Johnson Inc that was issued on November 8, 1994 is used for this purpose.
• a sample of the material to be tested in the form of a rectangle 5 cm by 20 cm is laid on a horizontal support surface.
• 3 cc of test fluid is deposited on the virgin sample and the sensor of the instrument is placed in contact with the absorbing surface of the sample. After 30 minutes from the fluid discharge the pressure reading in millimeters of mercury (mmHg) is recorded.
• mmHg millimeters of mercury
• the sensor is removed, an additional load of 3 cc of test fluid is
• Test fluid synthetic menstrual liquid with protein having a viscosity of 25 cps.
• Purpose to determine fluid migration profile of test fluid in a sample material.
• Test procedure a sample of the absorbent material in the form of a rectangle 10 cm X 10 cm is laid on a flat surface and 1 cc of test fluid is discharged in the center of the absorbent surface. After the liquid has disappeared the surface area of the stain is measured and recorded. A comparatively small surface area indicates that the absorbent material has a good wicking power in the Z direction (vertical).
• Test fluid synthetic menstrual fluid with protein having a viscosity of 25 cps.
• Test procedure the time required for a 5 cm X 20 cm sample to absorb 5 cc of test fluid fed to the sample from an
• Purpose the purpose of this test is to assess the propensity of a fluid present in an absorbent material under pressure to wet back an adjacent surface in contact therewith.
• test fluid 10 cubic centimeters of test fluid is allowed to rest 15 minutes and it is covered with a NuGauze brand pad. A pressure of 10.48 kPa is applied over the NuGauze pad. After 3 minutes, the amount of fluid (mass) captured by the pad is measured and reported in percentage on the basis of the dry weight of the pad.
• Test Fluid synthetic menstrual fluid with protein having a viscosity of 100 cps.
• test fluid is deposited on the absorbent surface of the structure. After 20 minutes following the test fluid discharge each layer of the absorbent structure is weighted to determine the individual amount of fluid take-up.
• Test fluid synthetic menstrual fluid with protein having viscosity of 100 cps.
• Purpose to determine the porosity distribution profile in an absorbent structure.
• Test procedure A GATS (Gravimetric Absorbency Test System) is used to determine the amount of liquid retained in the sample at different hydrostatic negative pressures.
• the results are then converted to interstice size values using a known formula.
• the GATS apparatus uses a "medium" fritted disc (CANADAWIDE) having a 90 mm diameter.
• the fritted disc is in liquid communication with a vertical burette containing test liquid.
• the vertical distance between the meniscus in the burette and the top surface of the fritted disc on which the sample is deposited defines the hydrostatic pressure exerted on the sample.
• the burette is continuously replenished with liquid at the same rate at which the liquid is being absorbed by the sample.
• the amount of liquid absorbed by the sample is then measured for the following neqat ive hydrostatic
• interstice sizes is meant the equivalent interstice diameter.
• test results clearly demonstrate the advantages of the liquid absorbent article in accordance with the invention. Note particularly the dramatic improvement in penetration time and capillary pressure over the control. The ability of such liquid absorbent article to manifest a powerful capillary attraction is particularly useful in sanitary napkin
• the results of test I show that the liquid absorbent article in accordance with the invention collects virtually all the liquid discharged on the sanitary napkin, totally desorbing the cover layer and leaving only a small amount of liquid in the transfer layer.
• the control has a less favorable fluid distribution pattern, with only 48 % of the total liquid discharge being contained in the absorbent core.

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• 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)
• Orthopedics, Nursing, And Contraception (AREA)

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• 1996
  • 1996-09-20 EP EP96930001A patent/EP0927015A1/de not_active Withdrawn
  • 1996-09-20 WO PCT/CA1996/000626 patent/WO1997013484A1/en not_active Ceased
  • 1996-09-20 AU AU69220/96A patent/AU6922096A/en not_active Abandoned
  • 1996-09-20 CA CA002237154A patent/CA2237154A1/en not_active Abandoned
  • 1996-09-27 UY UY24333A patent/UY24333A1/es not_active Application Discontinuation
  • 1996-10-04 CO CO96052881A patent/CO4750792A1/es unknown
  • 1996-10-04 HN HN1996000063A patent/HN1996000063A/es unknown
  • 1996-10-10 GT GT199600084A patent/GT199600084A/es unknown
  • 1996-10-11 ZA ZA9608624A patent/ZA968624B/xx unknown
  • 1996-10-11 AR ARP960104724A patent/AR003870A1/es unknown
  • 1996-10-21 TW TW085112832A patent/TW345495B/zh active

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