MXPA99003765A - Readily defibered pulp products and method of their manufacture - Google Patents

Abstract

The invention relates to cellulose fluff pulp products that are debondable into fluff with markedly lower energy input, to a process for making the products, and to absorbent products using the fluff. Most of the pulp products show no reduction in liquid absorbency rate from that of untreated fiber and significantly higher rates than pulps treated with the usual debonding agents. The products are made by adhering fine noncellulosic particles to the fiber surfaces using a retention aid. The fiber is preferably treated with the retention aid in an aqueous suspension for a sufficient time so that the retention aid is substantively bonded with little or none left free in the water. The fine particulate additive is then added and becomes attached and uniformly distributed over the fiber surfaces with very little particle agglomeration occurring. The fiber is most usually not refined or only very lightly refined before sheeting. However, it may be significantly refined to produce a product having a very high surface area. Kaolin clay is a preferred particulate additive. The treated pulp may be mixed with other fibers before sheeting or after it is debonded into a fluff. The fluff is highly advantageous in the absorbent portions of personal care products such as diapers or sanitary napkins.

Description

EFFECTIVELY DEFIBRATED PULP PRODUCTS AND METHOD FOR MANUFACTURING The invention is a modified wood pulp product especially useful for the production of lint designed to be used as the absorbent layer in disposable diapers, sanitary napkins and similar absorbent sanitary products. The product can be debonded from the sheet form to create an absorbent fluff by significantly reducing the required fiberization energy compared to untreated pulps. The generation of static during the formation of the fluff is markedly reduced or eliminated. The lint has a lower knot content and has a water absorption rate essentially equivalent to that of the untreated fiber. The products can also be used in sheet form, mixed or not with other fibers, such as an absorbent layer in disposable diapers, sanitary napkins and similar sanitary products.

BACKGROUND OF THE INVENTION Absorbent hygienic products using fibrous wood pulp have been available for many years. However, the tonnage used for this purpose was relatively modest until the arrival of disposable diapers, first for infants and later for incontinent adults. The arrival of these products and their use worldwide created a explosion in demand. The basic product that comes out of the bin is very commonly called a "fluff pulp". In the United States it is typically a fully bleached southern pine sulfate wood pulp produced in leaves of relatively heavy caliber and high base weight. The product is redevated in continuous rolls for its shipment to the consumer. Since the sheet product is designed to be reprocessed later into individual fibers, a low sheet strength is desirable and typically very little or no refining is used prior to sheeting. The requirements for uniformity of surface and formation are moderately moderate. At the customer's plant, the rolls are continuously fed into a device, such as a shredder, to be reduced as reasonably as possible to individual fibers. The fiberized product is generally called a "fluff" of cellulose. This is then continuously drawn into the air to form pads that will be included in the desired product. The patent of E.U. No. 3,975,222 to Mesek is exemplary of said procedure. There are a number of quite recognized problems associated with the production of cellulose fluff. Shredders used for lint production consume a large amount of energy. In addition, the lint may contain significant numbers of bundles of fibers normally called knots or bundles. A more vigorous defibrization can reduce the content of knots but with the cost of a considerable rupture of fiber and a high content resulting from a very fine powdery material. To overcome this problem the pulp mill can add chemical binders before the formation of the sheet. These are usually cationic quaternary ammonium compounds with aliphatic substituents on the nitrogen atom which, in essence, coat the fibers with a hydrocarbon film and interfere with the natural hydrogen bonding tendency of the cellulose fibers. A typical binder can have the formula: R-i. • R3 x- R2 R4 wherein R-y and R 2 are long-chain or aliphatic polyether hydrocarbons, R 3 and R can be lower alkyl groups and X is a salt-forming anion. Examples of said compounds are observed in Canadian Patent 1, 151, 213 and Bréese, US patent. No. 4,432,833, the binder are effective in reducing energy consumption but create their own problem in the form of significantly more poor water absorption rates and a somewhat lower water retention capacity. Considerable research has been done to overcome this problem; e.g., as exemplified in May and others, US patent. No. 4,425,186 and Laursen, patent of E.U. No. 4,303,471. However, no satisfactory solution to the problem has been found so far. The handling during the papermaking process; e.g., by final pressing without water or with low moisture content or by using a Superior consistency can only contribute minimally to the reduction of fiberization energy. In this way, there has been an unmet need for a lint pulp that can be flighted with a significantly lower energy consumption without losing the excellent rate of water absorption of the lint made from an untreated pulp. The product of the present invention completely satisfies this need. Lyness et al., In the US patent. No. 3,998,690, separate a fiber supply material into two portions. One is treated with an additive to make it cationic while the other is treated with an additive to make it more anionic. The portions are then recombined. The object is to cause flocculation to reduce the loss of short fibers and fine powders. Clays are said to be one of the materials that increase the negative charge in the anionic portion. Weisman et al., In the US patent. No. 4,469,746, describe the coating of fibers with a continuous film of silica to improve hydrophilicity. The fibers themselves may be a naturally hydrophilic material, such as cellulose, or a hydrophobic polymer such as polypropylene. Jokinen et al., In the US patent. No. 5,068,009 describe the preparation of a cellulose fluff pulp with improved fibrillation characteristics. This is done by treating the cellulose with a cellulolytic or hemicellulolytic enzyme at any time during the pulp manufacturing process.

Kobayashi et al., In the US patent. No. 5,489,469, describe a mixed liquid-absorbent product in which water-insoluble hydrophilic fibers and a water-insoluble inorganic material are embedded in the surface of granules of water-absorbing polymer, such as a superabsorbent polymer. The inorganic material is chosen from a broad spectrum that includes alumina, silica, talc, clays and many others. The fibers can be cellulosic. Apparently, a leaf-pulped product is not contemplated by these inventors. Eriksson et al., In the US patent. No. 5,492,759, describe methods for adhering hydrophilic inorganic chemicals to fiber surfaces for the production of lint pulps. Aluminum and iron compounds are suggested. The hydrophilic layer results in a decrease in the contact angle and an increase in the absorption rate. Swedish patent application 8300460-6 describes the manufacture of a pulp easily deagglutinated by removing at least 75% of the fraction of fine powders that could pass through a 200 mesh screen. Up to 20-30% of the raw materials are removed before and during the formation of leaves. Swedish patent No. 462,918 discloses an easily deagglutinated wood pulp made by depositing highly finely ground alpha cellulose particles on the primary fibers. The particles act as separators between the fibers and prevent the strong agglutination of hydrogen between the adjacent fibers.

Chauvette et al., In the US patent. No. 5,562,649 disclose an absorbent and flexible pulp sheet made by incorporating an desaglutinapte and then perf-enhancing the product. The material can be used as such as an absorbent layer in absorbent sanitary products. Vinson et al., In the US patent. No. 5,611, 890, describe a low-dusting handkerchief product, useful as a bath or facial tissue, which incorporates a particulate filler such as kaolin clay as a softening agent. Research Disclosure Abstract 93355052 (1993) discloses air-laid pads made of talc-treated wood pulp, useful as oil-absorbing products or as a low-density hydrophobic pad used as a covering material for diapers or other products. absorbents It is said that the talc is distributed in the pad as aggregate materials, submicron particles or as coatings on the fibers. It is common practice to use talc in papermaking in very low percentages, eg, <1%, as an absorber of fats and resins extracted from the pulp. Mineral fillers have been used for a long time in paper production to lower costs and improve surface smoothness and print properties. Internal use can vary from as little as approximately 3% in products such as newspaper to as high as 30% or more in magazine paper. This internal use must be differentiated of the use of surface coatings that may also have a high content of mineral products. In common with cellulose fibers, most fillers have a negative surface charge. In this way, filler particles and fibers generally tend to repel each other unless some chemical material is used as a retention aid. Without such an auxiliary, the fillers are retained primarily by filtration in the network while it is dewatered on the forming wire and, since the individual filler particles typically have an average equivalent spherical diameter of only about 1 μm or less, it is usually quite high the loss in white water. The retention aids are mainly load modifiers. They may be anionic or non-ionic but are very commonly cationic materials. Depending on their use, the retention aids can act by making the cationic or less anionic fibers, or the cationic or less anionic filler, whereby there is an electrostatic attraction between the filler particles and the fibers. More generally, the retention aids are water soluble polymers of very high molecular weight that act as polyelectrolytes. As such, they act as bridges by linking filler particles to fibers. Typically they are polyacrylamides, polyamines, polyethyleneamines, polyoamidoamines or polyethylene oxides. The retention aids can act in a number of ways in addition to the load control to increase the retention of the filling. They can be used to attract individual filler particles to fiber surfaces to improve opacity. Most commonly, they are used in a manner that will cause flocculation of the fillers with themselves or with fibrils and fine fiber particles, whereby the effective particle size increases very significantly. As such, the flocs are retained much more effectively by filtration within the interstices of the drain sheet. Fillers affect the properties of the sheet of paper in many ways. The resistance, particularly the resistance to bursting and tension, can be reduced. Usually the opacity, brightness, surface smoothness and ink retention are increased. The particles adhered mainly to fiber surfaces interfere with fiber-to-fiber bonding. This increases the opacity due to the increased interfacial area which causes a higher proportion of incident or transmitted light to be scattered. Although there are exceptions, in the practice of general papermaking it is usually more desirable to promote flocculation of the filler so that it is retained predominantly in the spaces between the fibers, rather than on the surfaces of the fibers. Normally, the papers are highly refined to develop resistance and ensure excellent training. However, as far as the present inventors are aware, mineral fillers have never been used in conjunction with lint pulps that could be refined or unrefined to deliberately affect the loss of tensile strength to reduce the energy of debonding.

BRIEF DESCRIPTION OF THE INVENTION The present invention is a cellulose pulp product and the method of its manufacture. The product can be converted from sheets to individual fibers with significantly reduced energy consumption and very low static generation during debinding. It should be considered that the terms "deagglutination" or "deagglutination" have the above meaning, unless the context of use of the words clearly indicates a different meaning; e.g., a chemical "debinding agent" as described at the beginning added to a pulp suspension to reduce the strength of a leaf. The terms are synonymous with the words "defibrated", "defibrated" or "defibpzation". The unrefined pulps show essentially no reduction in the rate of water absorption in the final fluff. Other advantages of the product will also be apparent. The product comprises a sheet or net of relatively high base weight cellulosic fiber formed in wet in which the surfaces of the fibers are coated with finely divided fillers to reduce the fiber-to-fiber bond strength.

By wet formation it is intended to say the preparation of the sheet or network from a suspension in water by conventional papermaking techniques. The pulp products of the present invention are clearly differentiated from products designed for letters, pounds, magazines or similar papers. These are commonly refined very highly in relative form to develop network strength and should have base weights below about 100 g / m2. Some special papers, such as for covers, can have base weights that are significantly higher. Adequate resistance is essential. The papers are normally glued to improve the ink retention properties and other printing properties. The products of the present invention are not glued, and the strength properties such as tensile strength, bursting and tearing, which are considered essential in the papers, are generally much lower. The basis weight of the products of the present invention can be as low as about 250 g / m2 and is preferably approximately 550 g / m2 by hand. The fiber will very commonly be unrefined or only slightly refined, although the invention is not so limited. When a product with a high surface area is desired, the fiber will normally be refined significantly. The filler is present in an amount ranging from about 1-30%, based on the combined weight of filler and cellulose, most preferably between about 3-20%. The highest base weight of the products, their lower strength and the fact that they are not glued, serve to distinguish them clearly from ordinary papers that might contain similar quantities of fillers. The cellulose pulp of the invention can be manufactured using conventional sulphate (kraft), sulfite, chemithermomechanical or other well-known processes. The raw materials can come from various raw materials that contain cellulose.

Very commonly they will be perishable hardwoods, coniferous species, usually called coniferous woods; or mixtures of these materials. A preferred pulp is a bleached coniferous wood (kraft) pulp that would normally be designed for a final use of absorbent lint. Although so-called "dissolution pulps" can be used, they are not preferred due to their low yield and much higher cost.

Among the mineral fillers that are suitable are clays, both kaolin and bentonite; calcium carbonate such as powdered clay, lime or marble or precipitated calcium carbonate; and synthetic mineral fillers such as aluminosilicates or precipitated silica. Although titanium dioxide is normally used as a pigment to improve shine, it can also serve as a mineral filler. Talc (magnesium silicate) can be useful for certain purposes. This is not normally preferred in the liquid storage portion of absorbent products such as diapers since it tends to decrease absorption rates and hydrophilicity. However, for some products such as absorbents oil or in which the control of hydrophilicity is desired, this property can be advantageous. Also suitable are certain organic fillers such as those of the urea-formaldehyde type or polystyrene microspheres. The term "fillers" should be considered broad enough to include those mentioned above, as well as other inorganic, organic and synthetic fillers common in papermaking. Kaolin clays are the fillers that are preferred. The fillers are present in the product on a scale of about 1-30% of the total weight of the product, preferably on the scale of 3-20% by weight, and more preferably about 5-20% by weight.

The fillers are bonded to the fibers by the use of retention aids used in an amount of about 0.5-5 kg / t fiber, typically about 1-3 kg / t, although this will depend in some way on the particular retention aid. that is used. The retention aid should not be used in excess and should be added to the fiber before the addition of the filler so that it is bonded to the fiber leaving little or no free in the pulp suspension before the addition of the filler. This is done to promote the agglutination of the filler directly to the fiber and discourage flocculation of the fiber. Although it is not the most preferred procedure, it is within the scope of the invention to use the opposite approach and to alter the negative charge of the filling particles by treating them in an aqueous suspension with a retention aid and then adding the treated particles or less anionic to untreated cellulose fibers. It is also possible to mix fibers and filler particles and then add a suitable retention aid. However, it is important that the retention aid used and the conditions of use should be such as to avoid any significant flocculation of the particles and ensure uniform deposition on the fibers. An object of the invention is to provide a laminated fluff pulp that is easily deagglutinated with reduced energy consumption. Another object is to provide a laminated fluff pulp that is easily deagglutinated and that produces a fluff that maintains an excellent rate of water absorption. A further object is to provide a laminated fluff pulp that is not subjected to the generation of static electricity during the debinding process. It is also another object to provide an easily de-bleached pulp product having an exceptionally high surface area. It is also another object to provide a process for manufacturing lint pulps having the properties mentioned above. A further object is to provide a pulp product that is soft and absorbent and can be used directly as a component in personal care products.

These and many other objects will become readily apparent to those skilled in the art after reading the following detailed description along with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a bar graph showing the fiberization energy of the different product samples. Figures 2A, 2B, 3A and 3B are scanning electron micrographs of untreated fibers and fibers treated with 24.4% clay at respective magnifications of 150X and 8000X. Figure 4 is a scanning electron micrograph of a filled lithographic paper showing flocculating filler particles. Figures 5 and 6 are photographs showing, respectively, the effects of the generation of static electricity on untreated pulp vs. a product of the present invention. Figure 7 is a graph showing the variation in the basis weight of air-laid mats formed from conventional fibers and those of the present invention. Figure 8 is a graph showing the liquid absorbed vs. time for a fiber treated and not treated with added superabsorbent polymer.

Figure 9 is a graph showing the capacity for fluid retention vs. absorption time for lint pads formed from two commercial pulps and a product of the present invention using an inclined absorption test. Figure 10 shows a sanitary towel for menstrual protection made using a product of the present invention. Figure 11 similarly shows a baby diaper using one of the products of the invention.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The product of the invention can be produced using completely conventional papermaking techniques such as will be observed from the following example. Three test methods are generally used to evaluate the quality of the lint pulp. The fiberization energy requirement is determined using an instrumented laboratory scale crusher to measure the energy needed to fiber a certain pulp weight. The crusher used in the following tests was a Kamas Laboratory Mili, Model H01, manufactured by Kamas industp, AB. Vellinge, Sweden. The free height of the breaker bar was set at 4.0 mm, the sieve size was 19 mm and the rotor speed was set at 3024 rpm. The samples were conditioned at 50% relative humidity for a minimum of 4 hours before the test. The samples were cut into strips 5.0 cm wide and so as long as the sample would allow it. Sufficient strips were cut to produce about 150 g of fiberized pulp. The basis weight of the samples was previously determined and the speed of the crusher feed roller was adjusted to achieve a desired feed rate of 2.80 g / sec. The fiberization efficiency is determined by dry fractionation using a sonically agitated sieve stack using standard Tyler sieves of 5, 8, 12, 60 and 200 meshes having respective openings of 3.96 mm, 2.36 mm, 1.40 mm, 246 μm and 74 mm. μm. This is basically a determination of the percentages of knots, desired fiber and fine powders. It is considered that the material retained in the thickest sieve are knots and that the material passing through the 60 mesh sieve are fine powders. The rate of water absorption was determined using the automatic lint absorption quality test (FAQ) described in detail by Martinis et al., Tappi Annual Meeting Preprint No. 7-3, pp 1-8, Chicago (1981). The lint is first configured to create an air-formed pad inside a cylinder 160 mm long and 56.4 mm in diameter having a sieve of 16 meshes at the bottom. The area of the pad is 25 cm2. The tared cylinder is placed on a scale and the weight of the pad is adjusted to 4.0 g by carefully removing any excess fiber from the top with tweezers. The pad inside the cylinder is then placed in the tester and a 150 g plunger is lowered onto the lint mat. Water is then introduced into the base of the pad. The absorption speed is calculated from the time necessary for the water to rise by wicking from the bottom of the pad and make contact with the plunger; that is, through the thickness of the pad. You can also easily determine the dry volume, the wet volume and the liquid holding capacity.

EXAMPLE 11 Samples were obtained from a sulphate (kraft) wood pulp from bleached southern pine and never dried from a pulp mill in southeastern E.U. When the pulp is laminated and dried at the factory it is sold as Grade NB-416 by Weyerhaeuser Company, New Bem, North Carolina. This grade is produced as a commercial lint pulp and was used as a control material in all of the following examples. Other materials used were a retention aid "7135" supplied by Nalco Chemical Company, Naperville, Illinois and kaolin clay sold as a suspension 60% designated SWW and sold by J.M Huber, St. Louis, Missouri. The retention aid is a cationic polyamine of average molecular weight in a solution with 50% active material. This was diluted with ten parts of water to one part of 50% solution before use and was used at a rate of 3 kg / t based on the combined dry weight of clay and fiber. 20 305 x 305 mm hand towels were made using unrefined pulp at a desired basis weight of 750 g / m2 and density of 600 kg / m3. Clay retention was established at 5%, 10%, 20% and 30%. A batch of leaves without retention aid was made to observe how much clay could be retained by physical entrapment in the leaves. The ash content of these leaves showed that virtually no clay was retained. The clay particles were so fine that the very open, unrefined fiber matrix could not retain them by filtration and almost all the clay was transferred to white water. As mentioned before, in most papers it is desirable to flocculate the mineral filler while leaving the surface of the relatively uncoated fiber. This makes possible a maximum strength retention from the hydrogen bonds between fibers, but the increased size of the mineral filler flocs is sufficient to allow them to be captured by the fiber network during the formation of the sheet. For the present invention, an opposite mechanism is desired. The formation of filler flocs is discouraged, while the maximum fixation to, and the coating of the fibers is the mechanism that is preferred. This is accomplished by first adding the retention aid to the fiber suspension and allowing sufficient time for substantially all of the auxiliary to agglutinate to the surface of the fiber. Only then is the mineral filler added to the fiber suspension. The amount of retention aid used should not exceed that which will clump to anionic sites available on the fiber. Otherwise flocculation of the filler could occur. Although this is not especially harmful to achieve the goal of improved debonding characteristics, it does represent a waste of both retention aid and filler. Based on the desired base weight, the necessary amount of never dried pulp was weighed and retention aid was added at a load of 3 kg / t at the pulp suspension that had a consistency of 2-3%. The mixture was stirred for about 20 minutes to allow a maximum bonding of the retention aid to the fiber. The suspension was drained to remove any free non-agglutinated retention aid in the suspension. However, subsequent tests showed that this step was not necessary. The desired amount of clay was then added to the drained pulp; Water was also added to return the consistency to 2-3% and the suspension was stirred for an additional five minutes to allow the clay to clump to the fiber surfaces. Leaves were formed to a pulp consistency, based on the fiber plus clay retained, 0.2%. The leaves were initially dried and then pressed wet at a pressure of 380 kPa. After drying at 105 ° C and conditioning, the sheets were tested to verify the required debinding energy, evaluation of lint quality, absorption properties and clay retention. The dried handsheets were tested to verify the ash content before and after the fiberization. Comparison sheets were also made using 3 kg / t of a commercially available binder (Berocell 509, available from Eka Nobel) to simulate lint pulps treated with commercially available binder using this approach. An additional control sample was made using only clayless retention aid. Table 1 shows the sheet and the resulting lint properties obtained.

TABLE 1 Properties of leaves for hands and lint with clay added Treatment (Dontral Control + Desired clay level Auxiliary binder of treated in retention 5% 10% __%. ____ laboratory Properties of the sheet Basic weight, g / m 2 703 70 739 768 767 730 712 Caliber, mm 1 33 1 37 1 46 1 4 1 36 1 22 1 53 Density, kg / m3 530 514 508 549 562 600 466 Clay1",% 0 1 <2> - 6 5 15 7 22 6 284 (leaf shape) Clay '",% 0 1 < 2 > 20 6 26 6 (after fibpzation) Properties of the fluff Energy of 1 3 170 79 • 42 25 50 defibrated, kj / kg Total knots,% ND Absorption by test FAQ Time of 3 1 3 1 23 22 2 1 53 absorption, sec Speed of 27 7 28 8 31 1 28 1 25 8 25 7 15 'absorption, mm / sec (1) Determined by dividing the ash content between a factor of 0 86 (2) Actual ash content Various characteristics of the clay-coated product are readily apparent from the reference to Table 1. The added clay is substantially substantively quantitatively on the fiber treated with retention aid and surprisingly very little clay is lost during the fiberization. The energy of defibrization at all levels of clay use is dramatically lower than that needed for the control pulp and uses of 10% or more are significantly lower even than the pulp treated with binder. Of particular importance, the water absorption rates of all the samples treated with clay are not reduced in relation to the control samples and are approximately 65% higher than those of the material treated with binder. The water absorption times are about 35% faster than those of the control pulp and more than twice as fast as those of the pulp treated with binder. The control sample with retention aid but without clay had properties almost similar to those of the untreated control pulp, except for its slightly higher fiberization energy requirement. What is not shown in the table was the subjective observation that, in marked contrast to the control samples, the leaves treated with clay showed little or no generation of static defibption. The fibrillation energy data of Table 1 are shown graphically in Figure 1. It is noted that the fiberization energy increases by 20% from the addition of the retention aid alone. Apparently, the retention aid increases by itself the fiber to fiber bond. Without However, fiberization energy decreases below control pulp even at lowest level of clay addition and continues to fall as clay content increases. At 13.5% level of clay loading, fiberization energy is reduced to a level below that of chemically deagglutinated sheets with an energy consumption of only about 30% compared to that of control. It is evident that filler particles are highly effective at disrupting fiber-to-fiber bonding, even at low addition levels. scanning electron micrographs of fibers were revealing. As seen in Figures 2A and 2B, at a relatively low magnification of 150X, it was observed that untreated control fibers had a smooth and clean surface, while fibers treated with 24.4% clay had a very rough surface. At highest magnification of 8000X, shown in Figures 3A and 3B, individual clay platelets are easily observed on treated fibers. surface coverage even with as little as 5% clay content (not shown in micrographs) was surprisingly complete and uniform, and this was even more case with higher loads. Even when pulp was not refined, as in present case, e is usually at least a lesser amount of fibrification than occurs during pulping and bleaching processes. In scanning electron micrographs of FIG. 2A it is revealing to note that very few fibrils are observed on surface of uncoated fibers. Without However, significantly more fibrils are observed on samples coated with clay. As it is apparent in figure 3A, e were erected in a very similar way to bristles of a brush and are, toge with body of fiber, coated with clay particles to give a dendritic appearance similar to that of frost. comparison of Figure 2B with Figure 4 clearly shows marked difference between lint pulp of present invention and a filled paper. scanning electron micrograph to 200X of Figure 4 is on felt side of a lithographic paper with a calcium carbonate filler. In product shown, relatively little filler clings to fibers, but is retained primarily as flocs in interstices between fibers. Electrostatic phenomena were observed qualitatively during fibpzation and mat formation. It was observed that electrostatic accumulation was very significant for chemically deagglutinated pulp compared to untreated control, while essentially no accumulation of static was observed in clay-treated material. This is clearly shown in photographs of Figure 5, using an untreated lint pulp, and in Figure 6, where pulp is a product of present invention. rests of suspended fiber and a more poor mat formation are clearly visible in figure 5. e fiber remnants are eventually swept on mat and form lumpy areas or, by dragging against mat, can form strips which are areas of fiber. lower weight This is shown quantitatively in Figure 7, where it is shown variation in base weight of continuously formed mats. Two commercial North Carolina kraft lint pulps are used for comparison. One was not treated and o was treated with binder. clay-treated pulp materials came from large-scale pilot test that will be described in Example 3. vertical bars on graph represent two standard deviations in weight of mat. superior uniformity of clay treated pulp is immediately evident and is due to generation of reduced static during production of lint.

EXAMPLE 2 The samples described in example 1 were all based on hand sheets. These usually correlate well in most properties with machine-tested pulps. However, since the addition of clay to an essentially unrefined pulp is a radical departure from the normal papermaking practice, a test was made on a pilot-scale paper machine Noble and Wood continued to have a cutting width of 30 cm. The materials and the desired base weight and the density in the pilot machine were identical to those used in Example 1. The bleached wood fiber sulphate (kraft) from the southern identical pine was used again. The fiber was placed in water at 2-3% consistency and retention aid was added with continuous agitation for about 5 minutes. The material was drained to approximately 20% consistency and water was added again to return the consistency to the 2-3% level. Clay was then added at levels sufficient to achieve loading levels of approximately 5% and 10%. After slight agitation for about 5 minutes the consistency was reduced to about 0.7% and the pulp suspension was rolled continuously.

The results are shown in table 2.

TABLE 2 Properties of the clay treated pulp of the pilot scale test Commercial pulps Scale pulp and pilot Sample Untreated Pulp Control 5% of 10% treated with clay clay Binder Properties of the sheet Base weight, g / m2 780 700 474 456 584 Density, kg / m 605 515 445 524 469 Chemical properties Clay,% leaf shape (1) 7 11.6 Clay,% in the form of - - 7 10.5 fluff (1> Properties of the fluff Felling energy, kJ / kg 138 53 79 41 38 Total nodes,% 11 1 3 0 0 Absorption test FAQ Absorption time, sec. 2.8 5.8 2.8 2.4 2.2 Absorption speed, 28.8 14.6 32 34.1 36 mm / sec < 1) Determined by dividing the ash content by 0.86. Due to mechanical imitations, the desired conditions of base weight and density could not be achieved in the pilot machine. The values obtained for these two properties were significantly lower than those desired. However, again it is evident that the addition of clay was substantive, and that the properties of defibrization were similar to those of the leaves for hands. Even the addition of a nominal 5% clay reduced the energy of defibrization to almost half that of the laminated pilot control.

EXAMPLE 3 Since it was not possible to achieve the desired higher base weight due to machine limitations using the Noble and Wood pilot scale paper machine, a similar test was carried out on a larger pilot machine with a cutting width of 91 cm at Herty Foundation, Savannah, Georgia. All tests were done using a non-dried pulp similar to that used in examples 1 and 2.

TABLE 3 Properties of the clay treated pulp of the largest pilot scale test Level of clay desired Treatment Control 5% 10% Properties of the sheet Base weight, g / m 724 687 766 Caliber, mm 1.15 1.07 1.28 Density kg / m3 630 640 602 Clay'1 ',% (leaf shape) - 5.4 14.2 Clay'1',% (after the - 5.4 12.9 fiberization) Properties of the fluff Fiber energy, kJ / kg 127 72 26 Total knots,% 30 1 1 Absorption by test FAQ Absorption time, sec. 2.4 2.2 2.1 Absorption speed, 30.1 36.6 32.2 mm / sec. < 1) Determining dividing the ash content between 0.86. It is evident that the base weight has very little effect on the defibbing properties and the speed of absorption of the pulps, since the results are similar to those observed in table 2.

EXAMPLE 4 Most absorbent products for personal hygiene are now predominantly made using superabsorbent polymers (SAP) in conjunction with the cellulose fluff. In some cases, the polymer particles are physically fixed to the fibers by various mechanisms, for example as seen in Hansen et al., US patent. 5,308,896. Most commonly, the fiber particles and SAP are simply mixed in an air stream during the formation of the pad. Pads of the latter type were made from the pulp sheets with clay at the level of 10% made in the Noble and Wood pilot tests described in example 2. The sheets were fiberized and mixed with 40% based on the weight of final product. of an SAP, IM 3900, available from Hoechst Celanese Corp., Charlotte, NC, during the formation of air-laid pads. A similar set of samples was made using a bleached kraft pulp of commercially available southern pine. The never dried fiber used in all experiments was obtained from the raw material used to make this commercial pulp. The pads were compressed at similar densities, approximately 0.11 g / cm 3, under identical applied loads, and subjected to a gravimetric absorption test. In this absorption test, the pads are maintained under an applied load of 3.4 kPa and are moistened from the bottom with a synthetic urine composition. The weight increase from the consumption of liquid is measured continuously with a balance and graphically as grams of liquid absorbed per gram of dry pulp / SAP material as a function of time. Figure 8 shows a plot of the pulp treated with clay vs. the commercial lint pulp. The lint of the treated pulp has an equilibrium capacity approximately 7% higher than its untreated counterpart. The results show an increased absorbency in the compressed structures made in conjunction with superabsorbent polymers. It was also observed that the clay-treated fluff pulp exhibited greater softness and volume after dry compaction under the same load, as compared to the control pulp. This was observed both in the presence and in the absence of SAP. EXAMPLE 5 As will be seen in this example, the present invention is not limited to kaolin clay as the filler material. Using the never-dried fiber and the procedures of Example 1, samples of additional hand sheets were made in which the kaolin clay was replaced with precipitated calcium carbonate, pulverized calcium carbonate, bentonite clay and talc. This last product was used to prepare a hydrophobic material. The ppma material consisted of 65 g of dried weight in the fiber oven and 14 g, based on solids, of the filler (17.7% filler). The materials and sources are as follows: precipitated calcium carbonate (PCC) - Specialty Minerals, Longview, Washington; powdered calcium carbonate (GCC) - Microna S-93, Columbia River Carbonate Company, Woodland, Washington; Bentonite clay - Hydrocol HSUF, Allied Colloids, Suffolk, Virginia; and Talcum XP961, Luzenac America, Englewood, Colorado. The following table shows the filler content of the leaves (by ash formation), the absorption speed and the debonding energy: TABLE 4 Products with fillers that are not kaolin clay Filler material Retained filler,% < 1) Absorption speed Energy, mm / sea. kJ / kq Precipitated CaC03 9.9 31.6 76 CaCO3 pulverized 7.4 34.2 87.9 Bentonite clay 6.4 30.5 70.8 Talc 17.6 0.3 94.4 11 'Determined from the ash content and corrected for known weight loss of filler during ash formation. It can be seen that despite the lower retention of mineral filler than that achieved with the kaolin clay, the absorption rate was equivalent and the fiberization energy was essentially half that of the control sample of Example 1 .

EXAMPLE 6 Eriksson et al., In the US patent. No. 5,492,759, describe a method for making a cellulose fiber with increased surface area by depositing a silica coating on the fibers. The inventors discovered that the rate of liquid absorption was related to the surface area. The techniques of the present invention can also be used to make a fiber with an increased surface area but using a much simpler and more practical procedure for paper mills than those of Eriksson and others. Although most lint pulps are essentially unrefined or only lightly brushed in a refiner, the technology of the present invention can be applied to refined pulps to produce fibers with a very high surface area in the dry state. The filling particles avoid the crushing of the cellulose fibrils after drying. Approximately 2 tons of never dried pulp similar to that of the previous examples was used in a pilot scale test done on the Fourdrinier machine with a cutting width of 91 cm at the Herty Foundation, Savannah, Georgia. The pulp was refined at 230 mL CSF. A filler retention aid (Nalco 7607, Nalco Chemical Company, Naperville, Illinois) was added at a rate of 3 kg / t. After a short reaction time, 30% kaolin clay (based on dry pulp) was added. A rolled product was made as a basis weight of 750 g / m2 and a moisture content of 6%. The density of the leaf wasof 700 kg / m3, slightly higher than the desired value. Approximately 750 kg of clay treated sheet was produced. The results of the tests on the product can be found in the following table.

TABLE 5 Results of the large scale pilot trial of refined pulp Sample Control not refined Treated with clay produced in refined factory Clay content,% (1) 0 ax. 25 Defibrating energy, 131 56 kJ / kg Absorption speed 28.8 15.5 FAQ, mm / sec Surface area, m2 / g'2 ', < 1 7.6 defibrated (1) Determined by dividing the ash content by 0.86. < 2) B.E.T. nitrogen absorption method.

The defibration energy of the clay-treated pulp was significantly reduced compared to the commercially produced unrefined pulp and used as a control sample. The surface area of the treated material was equal to or better than the best obtained by Eriksson and others. The surface area of the pulp laminated and treated before defibration was measured as 7.2 m / g2. It was subjectively noted that the opacity of the material was Exceptionally high The lowest absorption rate of the clay-treated material was expected for a refined pulp. A refining still lighter than that used for the above material can contribute substantially to an increased surface area. Improvements are observed at refining values as high as 550 CSF, although the most significant increase in surface area is obtained at refined products of approximately 350 CSF or less. Although the rate of absorption of the products with an increased surface area may be lower than that of the unrefined pulps, the impulse force for absorption is increased. This can be considered analogous to a suction force that tends to absorb and distribute a liquid with which the product is in contact. The larger impulse force can be used to move the liquid further, retain the liquid more closely and, in combination with other materials, move the liquid more quickly. It can be advantageous to make mixtures of the above described high surface material with other fibers. These other fibers may have a cellulosic, chemically modified or non-cellulosic cellulose composition. As an example, a fiber having higher absorption rates or a higher volume can be mixed with the high surface area matepal to take advantage of the higher suction capacity of the latter material. For example, this added fiber could be a conventional untreated cellulose fiber or one of the treated and unrefined fibers of the previous examples.

Blends with non-cellulosic fibers can often be used to obtain advantages. Examples of these non-cellulosic fibers are synthetic polymer materials such as polyolefins, nylons and polyesters. Mixtures can have a ratio of 10-90% fiber added to 90-10% fiber with a high surface area. A particularly advantageous additive fiber would be an interlaced cellulose fiber. Very typically, the mixture would have approximately 25% of the high surface area material and 75% of the interlaced fiber. An exemplary interlaced fiber may be one available from Weyerhaeuser Company, Tacoma, Washington as a High Volume Additive or HBA ™ fiber. The blends can be made at any time, either before or after the addition of the retention aid and filling particles. Very typically, the refined fiber would be treated first with the filler, as in the present example, and then the added fiber would be added and mixed thoroughly. Although it is anticipated that in most cases a blended product in the form of a sheet could be prepared, it should be considered within the scope of the invention if the product were prepared as individual bulk fibers; e.g., by spray drying or other known means. When the other fibers mixed with the high surface area fibers are cellulosic, they would normally be refined only to a very high refining value, e.g., 550 CSF or more, or they would not be refined at all.

EXAMPLE 7 The liquid holding capacity can be measured by means of the FAQ test mentioned above. Another procedure that is an indicator of actual performance in a diaper or similar item is the inclined absorption capacity test. A sample having dimensions of 7 X 30 cm is cut from a lint pad spread to the air. This is placed on an acrylic plate on a support inclined at an angle of 30 °. The pads can be pressed to a predetermined density before starting the test. The support is on an electronic scale so that the weight can be constantly recorded as a function of time. The end of the pad is then slid into a constant height water reservoir and the weight gain is recorded over time. The tests are carried out in triplicate and the results are averaged. Figure 9 shows the results of the tests on a pulp treated with 10% clay, and compared with two pulps treated with binder and commercially available. The very significantly increased liquid retention capacity of the sample treated with clay is immediately evident.

EXAMPLE 8 Swedish patent No. 462,918 discloses the use of finely powdered alpha cellulose as a fluff pulp additive to reduce the debundling energy without the need for chemical additives. When they are laminated, the alpha cellulose particles are said to avoid surface contact between the fibers and reduce the natural forces of hydrogen bonding. The alpha cellulose particles (alpha content of 92.5%) had been sprayed by means not described to a particle size between about 0.001-0.1 mm. A use of 10 kg / t (1%) was noted without adding any other chemical. The leaves having a basis weight of approximately 800 g / m2 were wet-formed and dried. The leaves were defibrated in a non-described test apparatus and found to have a defibrating energy of 150 kJ / kg compared to 400 kJ / kg for the untreated pulp. The absorption capacity was also slightly increased. In an effort to duplicate the Swedish work, the never dried control pulp used in the above examples was treated with 1% and 4% microcrystalline cellulose Avicel® Type-PH101 from FMC Corp., Newark, Delaware. It has an average particle size of approximately 50 μm, which falls in the middle of the Swedish particle size distribution. Since a better description of powdered cellulose was not given in the Swedish patent, this material was chosen as its probable equivalent. Leaves were made for hands that had a base weight similar to that of the Swedish material.

In contrast to the Swedish results, no improvement was observed in defibering energy, as seen in the following table. The experiment was repeated using a retention aid (Nalco 7607 a 1. 5 kg / t) with the results being similar to those without the retention aid. An increase in the liquid retention capacity of the untreated samples was observed, but no differences in the absorption rate FAQ were observed. It was subjectively observed that the generation of static during defibration and during the training for the FAQ test was high, approximately the same as that of the control sample. TABLE 5 Use of fine particles dß cellulose as a potential deagglutination aid Control 1% of 4% of 1% of 4% cellulose cellulose finely fine fine particle fine particles with auxiliary retention assistant , g / r 785 778 772 768 768 Density, kg / m 521 494 511 473 512 Fiber energy 136 144 130 148 141 kJ / kg Capacity, g H20 / g 8.5 11.5 11 4 11.6 11.4 Absorption speed 3 311..55 30.8 31.3 29.8 31.7 FAQ, mm / sec In general, all products of the present invention will have a Kamas defibrillation energy of less than about 90 kJ / kg. With the exception of refined pulps with a high surface area, they will have a minimum FAQ absorption rate of at least approximately 25 mm / sec.

EXAMPLE 9 The high surface area product of Example 6 is mixed before rolling with an interlaced cellulose fiber in a ratio of 25% of the fiber treated with clay and 75% of the chemically interlaced cellulose fiber, by weight. The interlaced cellulose fiber is supplied as HBA ™ by Weyerhaeuser Company, Tacoma Washington. The mixed product is then rolled and dried in a normal manner. After defibring in a crusher, an air-laid network having a basis weight of 100 g / m2 is manufactured from the product. This network is reinforced by the addition of a binder material. In the present case, 15% by weight of an ethylene vinyl acetate latex is sprayed on both sides of the product after the network is formed. The agglutinated net is then dried and the latex cured. The product is beneficial as an acquisition / distribution layer in sanitary napkins or diapers. As such, it accepts an initial charge of fluid and distributes it in a storage area. As an alternative, the product is useful as towels.

As an alternative structure, the latex binder is replaced with a thermoagglutible fiber at the time the network is formed. A product of this type is prepared by the uniform inclusion of 16% by weight of Celbond fiber sold by Hoechst Celanese Corp., Charlotte, N.C. It is believed that Celbond is a two-component fiber that has a polyester core and a polyethylene shell. The formed product is passed over an area where hot air is passed at approximately 130 ° C through it to create a strong bond.

EXAMPLE 10 The fiber made of defibrated sheets similar to the product described in Example 4 is configured to create a network and is used to prepare sanitary napkins. The fiber used contains 10% kaolin clay. To this was added 15% by weight of the superabsorbent polymer to give an 85:15 mixture of treated fiber to SAP. As seen in Figure 10, a sanitary napkin 2 was formed using as an absorbent core portion 4 an air-laid network of the fiber / SAP blend with a base weight of 215 g / m 2 pressed to a thickness of 1.56 mm. and a density of approximately 0.14 g / cm3. This fiber network is backed with a thin sheet impervious to liquids of polyethylene film 6 and is enclosed within a moisture-permeable nonwoven envelope 8. A pressure sensitive adhesive 10 is formed on the underside of the wrapping and it is protected with a removable peeling strip 12. The tests show that the product has an excellent absorption of fluid. In another structure, the laminate can be used directly, without defibrization, either as the sole absorbent component or as a component in a multi-layer absorbent core portion.

Depending on the weight of the base, the density and other properties of the sheet, it may or may not be desirable to soften or soften it further. This can be done by any of the well-known methods; v.gr., by enhanced.

EXAMPLE 11 Similar to the product of Example 10, as seen in Figure 11, a baby diaper 20 is made using a main central portion having 20 parts by weight of fluff and 10 parts of the superabsorbent polymer. The treated fiber from which the lint is formed is similar to the previous example but contains only 5% by weight of kaolin clay. The lint containing SAP is laid in the air to form a pad 22 having a basis weight of about 500 g / m2. This lint layer is used as the liquid storage portion of the diaper. This is covered by a lighter acquisition / distribution layer 23 having a basis weight of approximately 200 g / m2 composed of the high surface area fibers prepared from the product of example 6. Alternatively, layer 23 may be formed from a mixture of high surface area fibers and interwoven fibers such as the Weyerhaeuser HBA fiber as shown in example 9. In turn, this is covered by a non-woven network permeable to liquids and that makes contact with the skin 24, and a backing of liquid-tight polyethylene film 26. Elastic strips 28 along the edges help to prevent spills when the diaper be in use Adhesive strips 30 are used to secure the diaper to the child. The product excellently absorbs a synthetic urine composition. Optionally, aita surface area fibers can be used as a core component. The products of the present invention have many advantages over similar products previously available. It will be understood by those skilled in the art that many variations in the products and method of their production will be possible that have not been suggested in the examples. Thus, the intention of the inventors is that these variations should be included within the scope and spirit of the invention if they are encompassed by the following claims.

Claims (59)

NOVELTY OF THE INVENTION REVNIDICATIONS

1. - An easily defibrated air-laid cellulose pulp product having a basis weight of at least about 250 g / m2, in which the hydrogen bonds between fibers are minimized by an effective amount of fine non-cellulosic particles bonded to said fiber surfaces before wet product formation.

2. The cellulose pulp product according to claim 1, wherein the base weight is at least about 550 g / m2.

3. The cellulose pulp product according to claim 1, wherein the non-cellulosic particles are a mineral filler selected from the group consisting of clays, calcium carbonate, talc and mixtures thereof.

4. The cellulose pulp product according to claim 3, wherein the non-cellulosic particles are kaolin clay.

5. The cellulose pulp product according to claim 1, wherein the non-cellulosic particles are present in an amount in the range of about 1-30%, based on the combined weight of the particles and the cellulose.

6. - The cellulose pulp product according to claim 5, wherein the non-cellulosic particles are present in an amount in the range of about 3-20%, based on the combined weight of the particles and the cellulose.

7. The cellulose pulp product according to claim 1, wherein the non-cellulosic particles are bonded to the cellulose fibers by a filler retention aid.

8. The cellulose pulp product according to claim 1, wherein the Kama fibrillation energy of the product is less than about 90 kJ / kg.

9. The cellulose pulp product according to claim 1, wherein the lint form has a water absorption rate measured by means of a normal FAQ test, of more than about 25 mm / sec.

10. The cellulose pulp product according to claim 1, wherein the fibers are essentially unrefined.

11. The cellulose pulp product according to claim 1, wherein the fibers are refined to a Standard Refining Canadian less than about 350.

12. The cellulose pulp product according to claim 10 or 11, mixed with 10-90% by weight of other fibers selected from the group consisting of cellulose fibers, chemically modified cellulose fibers and non-cellulosic fibers.

13. - The cellulose pulp product according to claim 12, wherein the other fiber is an interlaced cellulose fiber.

14. A method for manufacturing an easily defibrated air-laid cellulose pulp product having a basis weight of at least about 250 g / m2, which comprises placing the cellulose fibers in a dilute aqueous suspension, attaching the fine non-cellulosic particles to the surface of the fiber in an amount sufficient to substantially interrupt the agglutination of normal hydrogen between the fibers, configure the fibers by creating a sheet and drying the sheet.

15. The method according to claim 14, which comprises adding a filler retention aid to the fiber suspension, allowing sufficient time for the retention aid to attach to the surface of the fiber, adding the non-cellulosic particles to the suspension to bind to the fibers, and to laminate and dry the product.

16. The method according to claim 15, wherein all the retention aid is bonded to the surface of the fiber before the addition of the particles, to minimize the flocculation of the particles.

17. The method according to claim 15, wherein the retention aid is selected from the group consisting of polyacrylamides, polyamines, polyethylene imines, polyamidoamines, polyethylene oxides and mixtures thereof.

18. The method according to claim 14, which comprises adding a filler retention aid to an aqueous suspension of the filler particles to reduce the negative potential of said fillers without significantly flocculating the particles before adding them to the aqueous fiber suspension. of cellulose

19. The method according to claim 14, wherein the non-cellulosic particles are a mineral filler selected from the group consisting of clays, calcium carbonate, talc and mixtures thereof.

20. The method according to claim 19, wherein the particles are kaolin clay.

21. The method according to claim 14, wherein the non-cellulosic particles are present in an amount on the scale of about 1-30%, based on the combined weight of the particles and the cellulose.

22. The method according to claim 21, wherein the non-cellulosic particles are present in an amount on the scale of about 3-20%, based on the combined weight of the particles and the cellulose.

23. The method according to claim 14, wherein the product has a basis weight of at least about 550 g / mz.

24. - The method according to claim 14, wherein the product has a fiberization energy of Kamas of less than about 90 kJ / kg and the product in the form of fluff has a speed of water absorption measured by means of a normal FAQ test, of more than approximately 25 mm / sec.

25. The method according to claim 14, which comprises refining the pulp before joining the non-cellulosic particles to the fiber.

26.- An easily defibrated cellulose fluff pulp product having a basis weight of approximately 250 g / m2, and characterized by a low generation of static after subsequent defibration in which the joints are substantially interrupted of hydrogen between cellulose fibers by means of an effective amount of fine non-cellulosic particles attached to said fiber surfaces prior to the formation of the wet product.

27. The cellulose pulp product according to claim 26, wherein the base weight is more than about 550 g / m2.

28. The cellulose pulp product according to claim 26, wherein the non-cellulosic particles are selected from the group consisting of clays, calcium carbonate, talc and mixtures thereof.

29. The product of cellulose pulp according to claim 28, in which the non-cellulosic particles are kaolin clays.

30. - The cellulose pulp product according to claim 26, wherein the non-cellulosic particles are present in a amount on the scale of approximately 1-30%, based on the combined weight of the particles and cellulose.

31.- The cellulose pulp product according to claim 30, wherein the non-cellulosic particles are present in an amount in the range of about 5-20%, based on the combined weight of the particles and the cellulose.

32. The cellulose pulp product according to claim 26, wherein the non-cellulosic particles are bonded to the cellulose fibers by a filler retention aid.

33. The cellulose pulp product according to claim 26, which has a fiberization energy of less than about 90 kJ / kg.

34. The product of cellulose pulp according to claim 26, which in the form of lint has a water absorption rate measured by means of a normal FAQ test, of more than about 25 mm / sec.

35.- The cellulose pulp product according to claim 26, wherein the fibers are essentially unrefined.

36.- The cellulose pulp product according to claim 26, wherein the fibers are refined to a Canadian Standard Refining of less than about 350.

37. The cellulose pulp products according to claim 35 or 36, mixed with 10-90% by weight of other fibers selected from the group consisting of cellulosic fibers, chemically modified cellulose fibers and non-cellulosic fibers.

38.- The cellulose pulp product according to claim 37, wherein the other fiber is an interlaced cellulose fiber.

39.- A product of refined cellulose pulp in which the hydrogen bonds between fibers are minimized by an effective amount of fine non-cellulosic particles attached to said fiber surfaces, mixed with 10-90% by weight of other fibers selected from the group consisting of cellulosic fibers, chemically modified cellulose fibers and non-cellulosic fibers.

40.- The cellulose pulp product according to claim 39, wherein the cellulose pulp is refined to a Refined Canadian standard of less than about 350, before joining the non-cellulosic particles.

41. The cellulose pulp product according to claim 39, wherein the other fiber in the mixture is an interlaced cellulose fiber.

42.- A disposable absorbent product having a central absorbent portion comprising an easily de-binded cellulose product according to claim 1.

43.- The disposable absorbent product according to claim 42, comprising a central absorbent portion formed of lint made by shredding and air-stretching to create a cushion form of the product of confection with claim 1.

44. The disposable absorbent product according to claim 42, comprising a central absorbent portion of which at least a portion is configured from the product according to claim 1 to create a sheet form.

45.- A disposable absorbent product having a central absorbent portion comprising an easily deagglutinated cellulose product according to claim 11.

46.- The disposable absorbent product according to claim 45, comprising a central absorbent portion formed of lint made by defibrating and tending to the air to create a pad shape of the product according to claim 1.

47.- The disposable absorbent product according to claim 45, comprising a central absorbent portion of which at least a portion is configured from the product according to claim 1 to create a sheet form.

48. A disposable absorbent product according to claim 42, wherein the absorbent center is further mixed with a superabsorbent polymer.

49. A disposable absorbent product according to claim 45, wherein the absorbent center is further mixed with a superabsorbent polymer.

50. - The disposable absorbent product according to claims 42, 43, 44, 45, 46, 47, 48 or 49, wherein the product is a diaper.

51.- The disposable absorbent product according to claims 42, 43, 44, 45, 46, 47, 48 or 49, wherein the product is a sanitary napkin.

52. A disposable absorbent product having a central absorbent portion comprising an easily de-bleached cellulose product according to claim 1, wherein said easily de-binded product is mixed with 10-90% by weight of other fibers selected from the group which consists of cellulosic fibers, chemically modified cellulose fibers and non-cellulosic fibers.

53. The disposable absorbent product according to claim 52, comprising a central absorbent portion made by defibring and tending to the air to create a pad shape of the product according to claim 1.

54.- The absorbent product disposable in accordance with with claim 52, comprising a central absorbent portion of which at least a portion is configured from the product according to claim 1 to create a sheet form.

55.- A disposable absorbent product having a central absorbent portion comprising a cellulose product easily deagglutinated in accordance with claim 11, wherein said product easily deagglutinated is mixed with 10-90% by weight of other fibers selected from the group consisting of cellulosic fibers, chemically modified cellulose fibers and non-cellulosic fibers.

56.- The disposable absorbent product according to claim 55, comprising a central fleeced absorbent portion of lint made by defibring and tending to the air to create a pad shape of the product according to claim 11.

57.- The absorbent product disposable according to claim 55, comprising a central absorbent portion of which at least a portion is configured from the product according to claim 11 to create a sheet form.

58.- A disposable absorbent product according to claim 52, wherein the absorbent center is further mixed with a superabsorbent polymer.

59. A disposable absorbent product according to claim 55, wherein the absorbent center is further mixed with a superabsorbent polymer. 60.- The disposable absorbent product according to claims 52, 53, 54, 55, 56, 57, 58 or 59, wherein the product is a diaper. 61.- The disposable absorbent product according to claims 52, 53, 54, 55, 56, 57, 58 or 59, wherein the product is a sanitary napkin.