Product to promote fluid flow

Abstract

A cellulose pulp particle having the shape of a general prismatoid having two parallel bases, the pulp particle comprising pulp fibers in a wet laid pulp sheet form, one of the bases having an area that is equal to or greater than the area of the other base, the area of the larger base being equal to or less than 30 mm.sup.2 and equal to or greater than 8 mm.sup.2, the height of the particle, the perpendicular distance between the bases, being equal to or greater than 0.9 mm and equal to or less than 5 mm.

Claims

1. A cellulose pulp particle having the shape of a general prismatoid having two parallel bases, the pulp particle comprising hydrogen bonded cellulose pulp fibers in a wet laid pulp sheet form, one of the bases having an area that is equal to or greater than the area of the other base, the area of the larger base being equal to or less than 35 mm.sup.2 and equal to or greater than 8 mm.sup.2, and the height of the particle being equal to or greater than 0.9 mm and equal to or less than 6 mm, wherein the base of the particle has a dimension greater than the height of the particle, wherein the particle does not contain bulking fibers and wherein the particle has a basis weight of from 600 g/m.sup.2to 1000 g/m.sup.2.

2. The particle of claim 1 in which the general prismatoid is a simple prismatoid.

3. The particle of claim 1 in which the general prismatoid is a cuboid.

4. The particle of claim 1 in which the general prismatoid is a square cuboid.

5. The particle of claim 1 in which the general prismatoid is a general cylinder.

6. The particle of claim 1 in which the general prismatoid is a right general cylinder.

7. The particle of claim 1 in which the general prismatoid is a right circular cylinder.

8. The particle of claim 1 in which the particle is formed from two or more plies, each of the plies comprising hydrogen bonded pulp fibers in a wet laid pulp sheet form, the adjacent plies being adhered together along a base, the height of the particle is equal to or greater than 1.5 mm and equal to or less than 6 mm and wherein each of the plies has a basis weight of from 600 g/m.sup.2 to 1000 g/m.sup.2.

9. The particle of claim 8 in which the general prismatoid is a simple prismatoid.

10. The particle of claim 8 in which the general prismatoid is a cuboid.

11. The particle of claim 8 in which the general prismatoid is a square cuboid.

12. The particle of claim 8 in which the general prismatoid is a general cylinder.

13. The particle of claim 8 in which the general prismatoid is a right general cylinder.

14. The particle of claim 8 in which the general prismatoid is a right circular cylinder.

Description

(1) Several embodiments of the present invention are illustrated in the drawings.

(2) FIG. 1 is an isometric view of an embodiment of the present invention showing a “general prismatoid” having square shaped bases in which 1a is the cut edge of the particle and bases 1b are the surfaces of the original pulp sheet from which this particle was formed. The square shaped base is exemplary. The base may be rectangular, have undulating edges or jig-saw shaped edges. It may have any number of cut sides. It may have 3 up to ten or more sides. It may be a general prismatoid, a simple prismatoid, a cuboid or a square cuboid. The planes of the bases are substantially parallel because they are the surfaces of the original pulp sheet.

(3) FIG. 2 is an isometric view of a second embodiment of the present invention showing a cylindrical particle in which 2a is the cut edge of the particle and bases 2b are the surfaces of the original pulp sheet from which this particle was formed. The edges of the bases are shown as circular. Again this is exemplary. The edges can be any continuous shape. Among other shapes it may be a general cylinder, a right general cylinder or a right circular cylinder. These specified shapes are not limiting but only given as examples. The planes of the bases are substantially parallel because they are the surfaces of the original pulp sheet.

(4) FIG. 3 is an isometric view of a third embodiment of the present invention showing cylindrical particle in which 3a is the cut edge of the particle and base 3b is the surface of the original pulp sheet from which this particle was formed. This exemplifies a cylindrical particle in which the edges of the bases are other than a circle. The edges are shown as flower shaped. This shape is not limiting but only given as an example. The planes of the bases are substantially parallel because they are the surfaces of the original pulp sheet.

(5) FIG. 4 is an isometric view of a fourth embodiment of the present invention showing a general prismatoid particle cut from a material in which two pulp sheets 4a and 4b are adhered together with an adhesive 4c. The outer surfaces of the sheets 4a and 4b form the bases of the general prismatoid. It may be a general prismatoid, a simple prismatoid, a cuboid or a square cuboid. These shapes are not limiting but only given as examples. In the drawing the edges of the bases form a square. The square shaped base is exemplary. The base may be rectangular, have undulating edges or jig-saw shaped edges. It may have any number of cut sides. It may have 3 up to ten or more sides. The planes of the bases are substantially parallel because they are the surfaces of the original adhered pulp sheets. The two pulp sheets are exemplary. Two or more pulp sheets may be adhered together.

(6) FIG. 5 is an isometric view of a fifth embodiment of the present invention showing a general prismatoid particle 5b cut from a pulp sheet and having on one base a lamination film 5a and on the other base a lamination film 5c. The lamination films are exemplary of treating the bases of the particle with either a film or a chemical such as a hydrophilic or hydrophobic chemical. The laminations or treatment chemicals would be placed on the pulp sheet prior to the manufacture of the particles. The films could be either heat laminated or adhered to the pulp sheet. It may be a general prismatoid, a simple prismatoid, a cuboid or a square cuboid. In the drawing the edges of the bases form a square. These shapes are not limiting but only given as examples. The square shaped base is exemplary. The base may be rectangular, have undulating edges or jig-saw shaped edges. It may have any number of cut sides. It may have 3 up to ten or more sides. The planes of the bases are substantially parallel because they are the surfaces of the original pulp sheet.

(7) FIG. 6 is an isometric view of a sixth embodiment of the present invention showing a cylindrical particle 6b cut from a pulp sheet and having on one base a lamination film 6a and on the other base a lamination film 6c. The lamination films are exemplary of treating the bases of the particle with either a film or a chemical such as a hydrophilic or hydrophobic chemical. The laminations or treatment chemicals would be placed on the pulp sheet prior to the manufacture of the particles. The films could be either heat laminated or adhered to the pulp sheet. Among other shapes it may be a cylinder, a right general cylinder or a right circular cylinder. These specified shapes are not limiting but only given as examples The edges of the bases are shown as circular. Again this is exemplary. The edges can be any continuous shape. The planes of the bases are substantially parallel because they are the surfaces of the original pulp sheet.

(8) FIG. 7 is an isometric view of a seventh embodiment of the present invention showing a general prismatoid particle cut from two pulp sheets 7a and 7b adhered together with an adhesive 7c and having a lamination film 7d on one base and a lamination film 7e on the other base. The lamination films are exemplary of treating the bases of the particle with either a film or a chemical such as a hydrophilic or hydrophobic chemical. The laminations or treatment chemicals would be placed on the pulp sheets prior to the manufacture of the particles. The films could be either heat laminated or adhered to the pulp sheet. It may be a general prismatoid, a simple prismatoid, a cuboid or a square cuboid. These shapes are not limiting but only given as examples. In the drawing the edges of the bases form a square. The square shaped base is exemplary. The base may be rectangular, have undulating edges or jig-saw shaped edges or have a single unitary edge of any shape such as a circle or ellipse or flower shaped. It may have any number of cut sides. It may have 3 up to ten or more sides. The planes of the bases are substantially parallel because they are the surfaces of the original pulp sheets.

(9) FIG. 8 is an isometric view of an eighth embodiment of the present invention showing a general prismatoid particle formed from the portion of the pulp sheet left over after the general cylindrical particles have been cut from a pulp sheet. It is the section between 4 tangential cylindrical portions and is formed of four concave surfaces 8a that meet at points 8c. A base 8b is also shown. The shape of the concave surfaces will depend on the particular shape of the cylinders.

(10) FIG. 9 is an isometric view of an ninth embodiment of the present invention showing a general prismatoid particle formed from the portion of the pulp sheet left over after the general cylindrical particles have been cut from a pulp sheet. It is the section between 4 cylindrical portions that are spaced from each other. and is formed of four concave surfaces 9a that are joined at their ends by planes 9c. A base 9b is also shown. The shape of the concave surfaces will depend on the particular shape of the cylinders.

(11) These embodiments are exemplary of the shapes and types of particles that can be formed. It should be understood that any of the particle shapes may be made of more than one ply and may be treated as described herein.

(12) The bases of the particle may have the same or different areas. The area of the largest base, if the bases have different areas, or of a base, if the bases have the same area, will be equal to or less than 35 mm.sup.2 and equal to or greater than 8 mm.sup.2. Although square particles are shown, the length can be greater than the width. The thickness or height of the particle will be from 0.9 to 1.5 mm if the particle is a single thickness particle, from 1.8 mm to 3 mm if the particle is a double thickness particle, and from 2.7 mm to 4.5 mm if the particle is a triple thickness particle. The height can be as high as 6 mm. As described above the dimension of the base of the particle should be greater than the thickness of the particles so that the particles will lie on their bases in the absorbent article. As described below the thickness of a pulp sheet has a maximum dimension so there may be two or more thicknesses of pulp in some embodiments.

(13) The dimensions of the particle must be small if they are being used in an absorbent article such as a diaper, a feminine care product or an adult incontinent product. They must lie down within the garment and be form fitting to the contours of the body. They must provide comfort to the wearer. A large particle will not provide these attributes. Also they must be able to distribute evenly. Smaller particles will tend to distribute more evenly than large particles. It has been found that the smaller particles will absorb more quickly in repeated insults as compared to larger particles. This can be seen in the examples. It has also been found that round particles absorb more quickly in repeated insults than square or rectangular particles. This can also be seen in the examples. The particles cannot be too small or they will not lay right in the absorbent article.

(14) These particles are formed from pulp sheets or enhanced pulp sheets. In practice a pulp sheet made from any pulp may be used.

(15) The raw material for pulp may be any hardwood or softwood or other material commonly used for pulp, such as bagasse. It may be made from a chemical, mechanical, thermomechanical or chemithermomechanical process. In one embodiment a kraft pulp made from southern U.S. softwoods may be used. In another embodiment a kraft pulp made from southern U.S. pine, such as loblolly pine, may be used.

(16) A chemical pulp is manufactured by cooking the raw material in an alkali such as sodium hydroxide. The hydroxide may be combined with a sulfate to manufacture kraft pulp. The hydroxide may be combined with a sulfite to manufacture sulfite pulp. In the cook the lignin and hemicellulose are solubilized and separated from the cellulose. The yield of the pulp will depend on the amount of lignin and hemicellulose removed. Usually more hemicellulose and lignin is removed in sulfite pulping than in sulfate pulping. The hemicellulose and lignin are washed from the pulp and the pulp is then brightened with oxidizing agents by bleaching. Chlorine dioxide and chlorine are typically used as bleaching agents.

(17) A mechanical pulp is manufactured by grinding the raw material into fibers. The lignin and hemicelluloses in the raw material will for the most part remain with the fiber.

(18) A thermomechanical pulp is manufactured by steaming the raw material and then grinding the raw material into fibers. The steam softens the raw material and makes it easier to grind into fibers. The steam may remove some of the hemicellulose and lignin from the fiber during the process.

(19) A chemithermomechanical pulp is manufactured by treating the raw material with chemicals and steam and then grinding the raw material into fibers. The chemicals and steam may remove some of the hemicellulose and lignin from the fibers.

(20) The process, after forming the fibers, is the same for any of the fibers. The fibers are slurried in water and the slurry of fibers and water is flowed onto a moving screen. The purpose of the rest of the process is to remove water from the fibers and to cause the fibers to form into a self-supporting web, either by hydrogen bonding between the fibers in the case of chemical pulp, or by intertwining and hydrogen bonding in the case of mechanical, thermomechanical and chemithermomechanical fibers.

(21) Water is removed from the fibers as they pass along the screen. The fibers are then calendered between rolls to further remove water and to press the fibers together. The fibrous web is then passed to a drier to further remove water. The drier can be a through air drier or a steam heated can drier. In any case, the pulp mat must be thin enough to be thoroughly dried. Because of the requirements of the process, the pulp mat will have a thickness of from 0.9 mm to 1.5 mm. A typical pulp mat can have a thickness of 1.2 mm.

(22) In the wet end of the pulp process, hydrophilic chemicals can be added to the pulp. These chemicals will remain in the pulp sheet.

(23) The thickness of the pulp mat will dictate the number of thicknesses in the particle.

(24) The basis weight of the pulp sheet can also vary because of the pulp being used and the manufacturing techniques. It may vary from 600 g/m.sup.2 to 1000 g/m.sup.2.

(25) The pulp sheet can be used as is for the manufacture of the particles or it can be adhered to another pulp sheet to form a double thickness pulp sheet. It can also be adhered to other pulp sheets to form multiple thickness pulp sheets before the manufacture of the particles. The outer surface of the pulp sheet or sheets may be treated in a size press or other apparatus to apply material to the sheet. It may also have film laminated to its outer surface.

(26) In commercial practice the particles would be formed by cutting the particles out of the pulp sheets or laminated pulp sheets using a rotary die cutter having the required particle shape and size, or by other cutting devices known in the art.

(27) The pulp sheet used for the particles in the examples below is commercially available Weyerhaeuser Columbus Pine pulp manufactured in Columbus, Miss. It contained only pulp fibers and contained no modified fibers or other types of fibers.

(28) The adhesive used for adhesive laminations in the examples was a 2″ wide commercial splicing tape, product number AR7418 CO#E5863, produced by Adhesive Research Inc., Glen Rock, Pa. This tape has an adhesive on both sides. The adhesive on one side is attached to a removable backing. In practice any adhesive that will adhere two sheets of pulp together may be used. It may be in sheet form or may be a liquid that can be coated on the pulp sheet by brush, roll or curtain coating. In any embodiment the adhesive must coat the entire surface of a roll so that the pulp portions forming the particles taken from the adhered rolls will be adhered together.

(29) The adhesive laminated pulp sheet used in the examples was produced by applying strips of the Adhesive Research adhesive tape described above to one side of a pulp sheet. The strips were laid side-by-side until the whole surface of the pulp sheet had the adhesive strips adhered to it. The tape backing was removed thereby exposing the other adhesive layer. A second pulp sheet was then pressed onto the first sheet resulting in the adhesive lamination of the two sheets. In practice the adhesive would be applied to one surface of a pulp sheet. The adhesive could be two sided adhesive material, or a liquid adhesive that is spread or sprayed or curtain coated onto the surface of the pulp sheet. The adhesive may be spread by a roll coater or other type of coater. Another sheet of pulp would be placed on the first sheet of pulp and the two sheets adhered together. The process would be repeated if a three ply pulp sheet were to be used.

(30) The lamination film used to produce the laminated pulp sheet was a 3.0 mil Doculam CR film available from Binder Products, Seattle, Wash. They are composed of general purpose polyesters. The laminator used was a model BA-PS27 made by Banner American Products, Inc., Rancho California, Calif.

(31) Pulp sheets having film laminated to their bases were produced by feeding the pulp sheet into the Banner American laminator at a speed setting of 10, roll temperatures of 325° F., top and bottom, and maximum pressure with the Doculam lamination film on the top and bottom unwinds. The pulp sheet had film laminated to its top and bottom surfaces. Pulp sheets adhered together to form a two ply sheet had film laminated to their bases in the same manner.

(32) In practice any type of laminating film may be used to provide a film on the exterior outer bases of the particles. The laminating films may be adhered by heat or by an adhesive.

(33) Twelve types of particles were provided for the examples.

(34) Particle 1 was a square cuboid as shown in FIG. 1. It was 3 mm long, 3 mm wide and the perpendicular distance between the bases was 1.2 mm. The areas of the bases of a particle were equal and the area of each base was 9 mm.sup.2. The particles were cut from a single thickness pulp sheet with a conventional paper cutter. The particles had no surface coating or lamination.

(35) Particle 2 was also a square cuboid as shown in FIG. 1. It was 5 mm long, 5 mm wide and the perpendicular distance between the bases was 1.2 mm. The areas of the bases of a particle were equal and the area of a base was 25 mm.sup.2. The particles were punched from a single thickness pulp sheet using a hand paper punch produced by Fiskars, item 23587097. The particles had no surface coating or lamination.

(36) Particle 3 was a square cuboid as shown in FIG. 4. It was 5 mm long, 5 mm wide and the perpendicular distance between the bases was 2.4 mm. The areas of the bases of a particle were equal and the area of a base was 25 mm.sup.2. The particles were cut from a double thickness pulp sheet. The double thickness pulp sheet was formed by adhering two pulp sheets together as described in the above description of forming a double thickness pulp sheet. The particles were cut using a conventional paper cutter. The particles had no surface coating or lamination.

(37) Particle 4 was a square cuboid as shown in FIG. 5. It was 5 mm long, 5 mm wide and the perpendicular distance between the bases was 1.2 mm. The areas of the bases of a particle were equal and the area of a base was 25 mm.sup.2. The particles were cut from a single thickness pulp sheet using a conventional paper cutter. The particle had a PET surface lamination on both bases.

(38) Particle 5 was a square cuboid as shown in FIG. 7. It was 5 mm long, 5 mm wide and the perpendicular distance between the bases was 2.4 mm. The areas of the bases of a particle were equal, and the area of a base was 25 mm.sup.2. The particles were cut from a double thickness pulp sheet. The double thickness pulp sheet was formed by adhering two pulp sheets together as described in the above description of forming a double thickness pulp sheet. The particles were cut using a conventional paper cutter. The particle had a PET surface lamination on both bases.

(39) Particle 6 was a right circular cylinder as shown in FIG. 2. It had a diameter of 3 mm and the perpendicular distance between the bases was 1.2 mm. The areas of the bases of the particle were equal and the area of a base was 7 mm.sup.2. The particles were punched from a single thickness pulp sheet using a Fiskars punch, item 23517097. The particles had no surface coating or lamination.

(40) Particle 7 was a right circular cylinder as shown in FIG. 2. It had a diameter of 6 mm and the perpendicular distance between the bases was 1.2 mm. The areas of the bases of the particle were equal and the area of a base was 28 mm.sup.2. The particles were punched from a single thickness pulp sheet using a Fiskars punch, item 23527097. The particles had no surface coating or lamination.

(41) Particle 8 was a right flower shaped cylinder as shown in FIG. 3. The perpendicular distance between the bases was 1.2 mm. The bases had the same area and each base had a cross sectional area of 26 mm.sup.2. The particles were punched from a single thickness pulp sheet using a Fiskars punch, item 23627097. The particles had no surface coating or lamination.

(42) Particles 1A, 2A, 6A, and 7A, are PET surface lamination versions of particles 1, 2, 6, and 7 respectively.

(43) FIG. 9 is an isometric view of the apparatus used for in-house loaded acquisition testing in Example 1. A cylinder 9a is attached to a square plate 9b. The lower half of the apparatus 9c is a matching plate to 9b.

(44) FIG. 10 is a side view schematic of the layers of the commercially available diaper used in Examples 2 and 3. The outside of the diaper is the backsheet 10a. A tissue 10b lies on top of the backsheet 10a and underneath the fluff and SAP storage core or member 10c. On top of the storage core 10c is another tissue layer 10d. On top of the tissue layer 10d is an acquisition patch 10e, and on top of the acquisition patch 10e is a top sheet 10f which is in contact with the wearer's skin.

(45) The fluff pulp used in the specially made pads was commercially available Weyerhaeuser NB416, manufactured in New Bern, N.C. It was fiberized on a Fitz Hammer Mill, model DAS06, milled with a fixed hammer rotor, at 10,000 rpm, with a breaker bar gap of 3 mils, with a feed rate of about 50 g/minute, with no screen.

(46) The topsheet used in the specially made pads in the examples was a spunbond polyester web, with a basis weight of 15 gram per square meter and a caliper of 1.8 mm, commercially available from First Quality Nonwovens Inc, product #SB1501810.

(47) The tissue used in the specially made pads in the examples was produced by Cellu Tissue Holdings, Alpharetta, Ga., grade 32201-1, with a basis weight of 18 g/m.sup.2.

EXAMPLE 1

(48) The experimental pads for Example 1 below were produced as follows. Six inch diameter pads containing these pulp sheet particles were made as follows. A mass of 4.0 grams of fiberized NB416 and 1.0 gram of Hysorb 8600 superabsorbent were fed into a six inch airlaid pad former and airlaid onto an 8 inch square of tissue. This resulted in a 5.0 gram airlaid pad with a basis weight of 274 grams per square meter, not including the tissue. Production of such airlaid pads is well known in the art. The airlaid pad was then laid onto an 8 inch square of blotter paper for conveyance. An additional 5.0 grams of additional NB416 fluff was evenly placed on top of the pad for the control pad, and 5.0 grams of pulp particles were evenly placed on top of the other pads. A 6 inch circle of tissue was placed directly on top of the pads. The pad was then placed into a square plastic mold with a 6 inch circular cylinder cut of the center. An 8 inch square of top sheet was then laid on top of the mold. A matching 6 inch circular plug was then placed into the center of the mold on top of the pad resulting in the corners of the top sheet extending out beyond the plug. Two small 0.5 mm thick metal shims were placed on top of the square mold on opposite corners. The mold and its contents were then put between two 12 inch square aluminum plates and compressed at force of 7 tons on a Wabash hydraulic press, model 125-15-SIMX, manufactured by Wabash MPI, Wabash, Ind. The mold surrounding the pad was removed, and the corners of the topsheet were smoothed back down. The caliper of the pad was measured. If the pad was not in the target caliper range of 2.40-2.60 mm, the compression procedure was repeated until the target caliper was achieved.

(49) The acquisition test frame was manufactured in-house and is shown in FIG. 9. It can be described as follows. A Plexiglas tube of a 6 inch height, an outer diameter of 1.5 inches, and an inner diameter of 1.125 inches is permanently attached to the center of a 10 inch square Plexiglas plate. The plate is 5 mm thick with a 1.125 inch hole cut out of the center. This top plate and tube together weigh 425.55 g. The bottom plate is also a 10 inch square, 5 mm thick, but with no holes.

(50) The compressed pads were then placed and carefully centered on the bottom plate of the acquisition test frame, and the blotter paper was carefully removed. The top plate was then carefully centered and placed on top of the pad and the bottom plate. One 125 gram weight was then placed onto each of the four corners of the top plate, with the center of the weight located 1 inch from the two sides forming the corner. A small funnel with a delivery spout of 5 mm in diameter was placed inside the tube on the top plate with the bottom of the funnel being 2⅞ inches above the top surface of the pad. Thirty milliliters of synthetic urine was quickly poured in the funnel and a stopwatch started. The stopwatch is stopped when the meniscus of the synthetic urine falls below the bottom of the tube in the top plate. This time is the acquisition time for the “first insult” and was recorded in seconds. A second stopwatch was started when the first one was stopped. When 20 minutes had elapsed on the second stopwatch, the insult procedure was repeated with a second 30 milliliter dose in exactly the same manner with the recorded time being the second insult time. After another waiting period of 20 minutes, a third 30 milliliter dosage was added in exactly the same manner with the recorded time being the third insult time. The acquisition rate was calculated by taking the insult volume, 30 ml, and dividing by the individual acquisition times. The results for a fluff control and particles 1 through 8 are shown in Table 1.

(51) TABLE-US-00001 TABLE 1 Loaded Acquisition Rate (ml/sec) Number 1st 2.sup.nd 3.sup.rd of Insult Insult Insult Sample Tests ave s.d. ave. s.d. ave. s.d. NB416 6 1.3 0.1 1.6 0.1 1.7 0.1 Fluff Particle 1 3 2.1 0.2 4.0 0.3 3.8 0.3 Particle 2 1 1.4 — 2.4 — 2.3 — Particle 3 3 2.4 0.0 6.1 0.7 6.6 0.3 Particle 4 3 1.8 0.2 3.6 0.4 3.6 0.3 Particle 5 3 2.6 0.4 5.9 0.7 6.5 0.4 Particle 6 3 2.2 0.1 4.2 0.7 4.1 0.4 Particle 7 3 1.8 0.1 2.7 0.1 2.5 0.3 Particle 8 1 1.9 — 3.5 — 3.3 —

(52) For absorbent products, a fast acquisition is preferable since this indicates that the fluid expressed is rapidly taken up into the product and there is less chance of leakage and would give a more comfortable feeling to the user since the article would feel dryer on the skin. In every case, the particles performed better than an equivalent weight of fluff. The adhesive laminated particles, particles #3 and #4, showed the best acquisition times. It is believed that during the insult, the particles swelled causing a larger void for the insulting liquid to pass more freely. In terms of cross sectional area, the smaller particles performed better. Three mm circles were better than 5 mm circles, and 3 mm squares were better that 4 mm squares. In general, circles seemed better than squares.

EXAMPLE 2

(53) The diapers used for Example 2 and Example 3 were obtained commercially. A cross section of the diaper is shown in FIG. 9. The layers of the diaper, starting from the skin contact side are: nonwoven topsheet, high loft nonwoven acquisition layer, tissue, fluff and SAP (superabsorbent) storage core, tissue, and a polymer film-nonwoven laminate. The diaper had a foam type waistband with Velcro fasteners and 2 elastic leg strands and 2 elastic inter-leg gather strands. The backsheet was a white, breathable, nonwoven lamination. The entire diaper weighed 40 grams, with the fluff core weighing 12.6 g, the SAP weighing 10.9 g, the acquisition layer weighing 0.23 g. The entire diaper was 47 cm in length, 38 cm wide in the back, 28 cm wide in the front, and 23 cm at its narrowest point. The acquisition layer was 16 cm in length, 5 cm in width, resulting in a basis weight of 30 g/m.sup.2. The fluff and SAP core was 40 cm in length, and a uniform 12 cm in width.

(54) In sample 1, the diapers were used as is for the tests. In sample 2, the sides of the top sheet were cut along the side edge of the diaper, pulled back, replaced, and resealed with a hot air gun as a control for the diapers using particles. In sample 3, the sides of the top sheet were cut along the side edge of the diaper and the acquisition layer was removed. In examples 4-6 the sides of the top sheet were cut along the side edge of the diaper and the acquisition layer removed and replaced with particles of the type shown in the Table 2 in the amount shown in Table 2. In samples 3-6, the topsheet was replaced in the same manner as sample 2.

(55) The diapers were tested for loaded acquisition times on an Anarewet Plus tester, obtained from Courtray Consulting, Douai, FRA. The basic operating procedure is as follows. Up to three diapers or test specimens are placed on top of a flat inflatable rubber bladder and a thick plastic plate is placed on top. The rubber bladder is inflated to the desired pressure. An aliquot of the desired fluid is automatically added to the insult point of the specimen and the time it takes to be fully absorbed into the diaper is electronically measured. After a specified pause, the insult procedure is repeated, followed by an additional pause and insult.

(56) For both Examples 2 and 3 the insult point was 0.75 inches from the front edge of the acquisition patch. The front edge of this patch was approximately 5 inches from the front edge of the diaper. The pressure applied to the diaper was 10 mb. The volumes of the three insults were 60 ml each, and the pauses between the insults were 300 seconds. In this manner the loaded acquisition times were obtained and are listed in table 2.

(57) TABLE-US-00002 TABLE 2 Weight of Loaded Acquisition Time Particles or (sec) Acquisition 1st 2nd 3rd Acquisition Layer Insult Insult Insult Total Sample Layer (g) ave s.d ave. s.d ave. s.d ave. s.d. 1 As is 0.23 17 1 39 6 64 11 119 17 2 As is but 0.23 20 3 43 7 68 13 130 22 opened 3 Removed 0 22 1 50 4 85 9 158 14 4 Particle 1 2.0 16 2 32 2 51 2 100 6 5 Particle 1 0.5 22 3 47 11 76 19 144 33 6 Particle 3 2.0 12 1 19 2 60 6 91 8
As show in the table, opening and reclosing the diaper increases the acquisition time slightly. This is a known phenomenon due to the disruption of the contact between the top sheet and the acquisition layer. The higher the level of contact there is, the faster the acquisition is. The table also shows that completely removing the acquisition layer raises the acquisition times substantially as expected. Replacing the acquisition layer with 2.0 gram of particle type 1, lowered the acquisition time by about 25% when compared to the control, “as is but opened” diaper. When the acquisition layer was replaced with only 0.5 g of particle 1, the acquisition time was slightly more than the “as is but opened” control diaper. When the acquisition layer was replaced with 2 grams of particle type 3, the double thick particle, the acquisition time drops about 30% when compared to the “as is but opened” control diaper. Because of the significantly higher basis weight of the particles compared to the high loft acquisition layer, a significantly higher total weight of particles had to be added to get a reasonable coverage, since each particle weighed on the order of 0.01-0.03 grams.

EXAMPLE 3

(58) Example 3 illustrates another experiment run in an exactly same manner as Example 2 on the Anarewet tester. Table 3 shows the results of experiment.

(59) TABLE-US-00003 TABLE 3 Weight of Loaded Acquisition Time Particles or (sec) Acquisition Number 1st 2.sup.nd 3rd Sam- Acquisition Layer of Insult Insult Insult Total ple Layer (g) Obs. ave. ave. ave. ave. 1 As it but 0.3 1 24 49 78 151 opened 2 Particle 2A 2.2 1 15 30 46 91 3 Particle 1A 2.2 1 13 20 30 63 4 Particle 5 2.2 1 8 9 12 29 5 Particle 7A 2.2 1 16 29 15 60 6 Particle 6A 2.2 1 13 19 25 57 7 Particle 8 2.0 1 15 25 39 79

(60) Samples 2-6 are all PET laminated particles of various shapes where particle 5 is also an adhesive laminated, double thick particle. Sample 1, the control, is reasonably close to the identical control in Example 2. Changes in ambient temperature and humidity can affect the acquisition time, and diapers do have a natural variability between them. The same trends appear in Example 3 as Example 2. Smaller circles and squares show an improvement with lower acquisition times than larger ones, and circles generally have a lower acquisition time than squares. When comparing PET laminated particles to non-laminated particles, one can see a sharp drop in the laminated particles acquisition time. For particle 1a, which is a laminated square, when compared to particle 1, which is the same square but not laminated, shows a 37% drop in total acquisition time. For particle 5, which is the laminated version of particle 3, an adhesive laminated double thick square, the drop is 73%.

(61) While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.