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Detailed description of preferred embodiments

In one aspect, the present invention provides adhesive cellulose fiber product, the products include in situ cross-linking of the cellulose fiber. In this use of the terminology of the "in-situ crosslinked cellulosic fibers" during the formation of the web that has been cross-linked cellulosic fibers. Therefore, the product of this invention comprising the first formed and then during the web-forming process to introduce network conventional network the cross-linked cellulose fibers.

Products include in situ cross-linking of the cellulose fiber. Because the fiber in the cross-linked during the web-forming process (i.e., in-situ), products include intrafiber cross-linking of the cellulose fiber (in other words, containing each of the fibrous an emplacing device of fiber) and fibers cross-linked cellulose fiber (in other words, containing between the fibers of the fiber /). The product containing the binding structure and includes intrafiber cross-linking cellulose fibers, their/through the fiber between the further crosslinked to the adjacent fiber. The product has the intrafiber cross-linking fiber related advantageous pine density and resilience performance and by the adhesion-imparting between the advantages of the structural integrity of the structure. Product is bonding, wherein the cross-linked fiber and the self-bonding structure is beneficial to the resilience and liquid collecting performance.

In one embodiment, the products can be produced by the following manner : (1) forming the cellulosic fiber web, at least some of the cellulosic fibers have already been used (if necessary) and cross-linking agent cross-linking catalyst processing ; (2) dry net; and (3) the temperature and time of being crosslinked paramatta under.

The product of the present invention is used for forming the suitable fiber including those that have a crosslinking agent and a crosslinking catalyst (if necessary) and then dried and is not solidified cross-linking agent of cellulose fiber. These drying and processing of fiber can be into the forming apparatus used for the subsequent product formation.

Many cross-linking agent and a crosslinking catalyst (if needed) of any one may be used to provide the product of this invention. The following is a representative list of cross-linking agent and a catalyst. The following provide each of the full text of the Patent to introduce clear as a reference.

Appropriate ureido-Dcarbamido crosslinking agent comprising substituted urea like hydroxymethylation urea , methylolated urea, methylolated lower alkyl cyclic urea, methylolated dihydroxy cyclic urea, dihydroxy cyclic urea, and lower alkyl substituted cyclic ureas. Specific ureido-Dcarbamido crosslinking agent comprises two a base b hydroxyurea (DMDHU, 1, 3-dimethyl -4, 5-dihydroxy-2-imidazolidinone), hydroxy dimethylol dihydroxy ethylene urea (DMDHEU, 1, 3-di-hydroxymethyl -4, 5-dihydroxy-2-imidazolidinone), dimethylol methyl urea (DMU, double [N-hydroxymethyl] urea), two hydroxy ethylene urea (DHEU, 4, 5-dihydroxy-2-imidazolidinone), two methylol Asia ethylene urea (DMEU, 1, 3-di-hydroxymethyl-2-imidazolidinone), and dimethyl hydroxy ethylene urea (DDI, 4, 5-dihydroxy -1, 3-dimethyl-2-imidazolidinone).

Suitable cross-linking agent comprises a dialdehyde such as C₂-C₈ dialdehyde (such as glyoxal), comprising at least one aldehyde groups of C₂-C₈ b glyoxylic acid analogs, and these aldehyde and two aldehydic acids analogue oligomer, such as in the U.S. Patent Nos. 4,822,453, 4,888,093, 4,889,595, 4,889,596, 4,889,597, and 4,898,642 those in the description. Other suitable dialdehyde cross-linking agent included in the U.S. Patent Nos. 4,853,086, 4,900,324, and 5,843,061 those in the description.

Other appropriate crosslinking agent including aldehyde and urea formaldehyde, shut the product. Refer to, for example, U.S. Patent Nos. 3,224,926, 3,241,533, 3,932,209, 4,035,147, 3,756,913, 4,689,118, 4,822,453, 3,440,135, 4,935,022, 3,819,470 and 3,658,613.

Suitable cross-linking agent composition comprising urea glyoxal adducts, for example, U.S. Patent No. 4,968,774, and as in the U.S. Patent Nos. 4,285,690, 4,332,586, 4,396,391, 4,455,416, and 4,505,712 described in glyoxal/cyclic urea Canada of the composition.

Other suitable cross-linking agent comprises a carboxylic acid crosslinking agent like many carboxylic acid. Multi-carboxylic acid cross-linking agent (such as, citric acid, c three carboxylic acid, and butanetetra-carboxylic acid) and catalyst described in U.S. Patent Nos. 3,526,048, 4,820,307, 4,936,865, 4,975,209, and 5,221,285. Of comprising at least three carboxyl groups C₂-C₉ multi-carboxylic acids (such as citric acid and the oxygen is joint II succinic acid) as described in the U.S use of cross-linking agent. Patent Nos. 5,137,537, 5,183,707, 5,190,563, 5,562,740, and 5,873,979.

Polymeric polycarboxylic acid is also suitable cross-linking agent. Suitable polymeric polycarboxylic acid crosslinking agent described in U.S. Patent Nos. 4,391,878, 4,420,368, 4,431,481, 5,049,235, 5,160,789, 5,442,899, 5,698,074, 5,496,476, 5,496,477, 5,728,771, 5,705,475, and 5,981,739. As the cross-linking agent of polyacrylic acid and related copolymers described in U.S. Patent Nos. 6,306,251, 5,549,791, and 5,998,511. Poly-maleic acid cross-linking agent described in U.S. Patent No. 5,998,511.

Specific suitable polycarboxylic acid crosslinking agents include citric acid, tartaric acid, malic acid, succinic acid, glutaric acid, citraconic acid, itaconic acid, tartrate ester list succinic acid, maleic acid, polyacrylic acid, polymethacrylic acid, polyethylene maleic acid, polymethylvinylether-co-maleate copolymer, polymethylvinylether-co-itaconic acid ester copolymer, copolymers of acrylic acid, and maleic acid copolymer.

Other suitable cross-linking agent described in U.S. Patent Nos. 5,225,047, 5,366,591, 5,556,976, and 5,536,369.

Suitable catalysts can include acidic salts, such as ammonium chloride, ammonium sulfate, aluminum chloride, magnesium chloride, magnesium nitrate, and alkali metal salt of phosphoric acid. In one embodiment, crosslinking catalyst is sodium hypophosphite.

Cross-linking agent and a catalyst may also be used or the mixture of the blend.

In order to be sufficient to carry on the above-mentioned intrafiber cross-linking and fiber cross-linked between the quantity of the cross-linking agent is applied to the cellulose fiber. Applied to the cellulose fiber is based on the number of the total weight of the fibers can be about 1-about 10 wt %. In one embodiment, the number of cross-linking agent for the fiber based a total weight of about 4 to about 6 wt %.

Appropriate forming the cellulose fibers of the product of the invention including the techniques known to those skilled in the field of those, including any can be cross-linked and from it to form a web or layer of any fiber or fiber mixture.

Although it can be obtained from other sources, cellulosic fibers derived from wood pulp. The method of the invention uses the appropriate wood pulp fibers may be from a known chemical method, such as the existence or not follow-up the bleaching bleaching the kraft paper pulping method for obtaining and sulphite process. Thermomechanical weapon law can also be used, or a combination thereof chemical thermomechanical weapon law method for processing wood pulp fiber. Preferred wood pulp fibers with chemical processing method. Grinding wood fibers can also be used, recovery or secondary wood pulp fiber and bleaching or unbleached wood pulp fiber. Also can use the softwood or hardwood. The details of the selection of wood pulp fibers is the ordinary technical personnel in this field the known. These fibers can also be to purchase from a number of companies, including Weyerhaeuser Company, the assignee of this invention. For example, the invention can be used by the United States long red of manufacturing cellulose fiber can be purchased from Weyerhaeuser Company to, its is: CF416, NF405, PL416, FR516 and NB416.

The invention can be used for the wood pulp fibers can also be pretreated prior to use. This pre-processing may include physical treatment, such as for performing steam treatment or chemical treatment.

Although content should not be interpreted as restrictive, fiber pre-processing examples include using a surfactant or a modified fiber surface chemical nature of the other liquid. Other pre-treatment comprises adding antibacterial agent, pigment, dye, thickening agent or a softener. In other chemicals can also be used, such as thermoplastic and thermosetting resin pre-processing of the fiber. The combination of pre-treatment may also be used. After the formation of fiber products in the post-processing can also be carried out in similar processing.

Can also be in accordance with the present invention is used in order to the known in the field of particle binder and/or thickening/softening agent treated cellulose fiber. Particle binder used for the other material, for example of highly absorbent polymer substance to adhere to the other and on the cellulose fibers. The use of appropriate particle binder and/or thickening/softening agent treated cellulose fibers and cellulose fibers to be combined with the above-mentioned preparation process disclosed in the following U.S. patents : (1) Patent number No. 5,543,215, topic "bonded particulate to the fiber polymer binder"; (2) Patent number No. 5,538,783, topic "bonded particulate to the fibers of the non-polymeric organic binder"; (3) Patent number No. 5,300,192, topic "bonding particles to the binder integrating activated adhesive manufacturing wet-laid fiber sheet"; (4) Patent number No. 5,352,480, title "using the re-activating the particles bonded to the fiber of the method"; (5) Patent number No. 5,308,896, topic "used for the high-bulk fiber of the particle binder"; (6) Patent number No. 5,589,256, topic "reinforced fiber thickening of the particle binder"; (7) Patent number No. 5,672,418, topic "particle binder"; (8) Patent number No. 5,607,759, topic "the particles bonded to the fiber"; (9) Patent number No. 5,693,411, topic "the water-soluble particles bonded to the fiber binder"; (10) Patent number No. 5,547,745, "particle binder" subject ; (11) Patent number No. 5,641,561, topic "the particles bonded to the fiber"; (12) Patent number No. 5,308,896, topic "used for the high-bulk fiber of the particle binder"; (13) Patent number No. 5,498,478, topic "polyethylene glycol as the fibrous binder material"; (14) Patent number No. 5,609,727, topic "for bonding particulate fiber product"; (15) Patent number No. 5,571,618, topic "bonded particles to the fibers and binder activation integrating a"; (16) Patent number No. 5,447,977, topic "used for the high-bulk fiber of the particle binder"; (17) Patent number No. 5,614,570, topic "containing with adhesive of the absorbent article of the bulked fibers"; (18) Patent number No. 5,789,326, topic "binder treated fibers"; and (19) Patent number No. 5,611,885, "particle binder" topic, the above-mentioned patents in the introduced as a reference.

In addition other than natural fibers, can also be added to a product comprising a polymer fiber, such as a polyolefin, polyamide, polyester, polyvinyl alcohol, polyvinyl acetate fiber of the synthetic fiber. Suitable synthetic fibers include, for example, polyethylene terephthalate, polyethylene, polypropylene, nylon and rayon fiber. Other suitable synthetic fiber including those fibers made from thermoplastic polymers, with the thermo-plastic polymer-coated cellulose fiber and other fiber, and wherein the at least one component comprises a multi-component fiber of thermoplastic polymers. Single-component or multi-component fiber can be made of polyester, polyethylene, polypropylene and other traditional thermoplastic fiber material. Monocomponent and a multi-component fiber may be obtained from commercial sources. Suitable bi-component fiber can be obtained from the   Company Hoechst-Celanese CELBOND fibers. Fiber product may also include a combination of natural and synthetic fibers.

In one embodiment, product further includes an adhesive. Adhesive is used to further enhance the structural integrity of the product. A suitable adhesive includes the thermoplastic material, such as bi-component fiber and rubber latex, and wet strength agent. When the adhesive is a thermoplastic fibers, fibers and cellulose fibers can be combined and then shaped to a cross-linking agent of the network. When the adhesive is the wet strengthening agent, the network can be subjected to a fiber cross-linking conditions on the Internet before applied to the adhesive.

Suitable thermoplastic fibers include a thermoplastic polymer-coated cellulose fiber and other fiber, and wherein the at least one component comprises a thermoplastic polymer of the multi-component fiber. Can be from polyester, polyethylene, polypropylene, and other conventional thermoplastic fiber material preparation of monocomponent and a multi-component fiber. Monocomponent and a multi-component fiber may be obtained from commercial sources. Suitable bi-component fiber can be obtained from the   Company Hoechst-Celanese CELBOND fibers.

Suitable wet strength agent comprises a nitrogen-containing group (e.g., amino) cationic modified starch,   and may, for example, from National   Chemical   Starch   Corp. , Bridgewater, NJ of those products obtained; latex ; wet strength resin, such as polyamide-epichlorohydrin resin (for example, KYMENE   557LX, Hercules, Inc. , Wilmington, DE), polyacrylamide resin (such as the United States Patent No. 3,556,932; another example is by American   Cyanamid Co. , Stanford, using CT PAREZ   631   NC trade names selling of polyacrylamide); urea formaldehyde and melamine-formaldehyde resin and resin invention. The field of use the paper wet strength resin in the general discussion of the invention and general application see TAPPI No. 29 thematic series, "paper and cardboard wet strength in the", wood pulp and paper industrial technical Society (new York, 1965).

In other embodiments, the product can be include other fibers. Other fibers include, for example, cellulose fiber, in particular the above-mentioned wood pulp fiber, and hemp fiber, cotton fiber, groundwood pulp fiber, bleaching and unbleached pulp fiber, recovery or secondary fiber.

Liquid retained in which a requirement of the embodiments of the product, the product can be further includes absorbing material (such as, high absorption polymer particles). In this use of the term "absorbent material" said absorption liquid and absorption capacity cellulose fibers generally greater than the composite material of the material of the component. Preferably, the absorbent material is a water-swellable, generally water-insoluble polymer material, the material can absorb at least about 5, the required approximately 20, and preferably about 100 times or more times as much as the salt water (such as, 0.9% saline) the weight of the in. Absorbent material can be used in the method of forming a composite material can be dissolved in the disperse medium swell. In one embodiment, the absorption material is not processing and swell in a dispersion medium. In another embodiment, the absorbent material it is applied to the absorbent material, the material of the product during the process for forming the anti-water absorption.

In the absorbent material the quantity of the product can be greatly depends on the required use of the product changes. Absorbent article, such as for a baby diaper of the amount of absorbent material in an absorbent core, in the composite material to the presence of the appropriate amount of the composite material is based on a total weight of about 2 to about 80 wt %, preferably about 30-about 60 wt %.

The absorbing material may include natural materials such as agar, pectin, and guar gum, and a synthetic material, such as synthetic hydrogel polymers. Synthetic hydrogel polymers include, for example, carboxymethyl cellulose, the alkali metal salt of polyacrylic acid, polyacrylamide, polyvinyl alcohol, ethylene maleic anhydride copolymer, polyethylene ether, [...] cellulose, polyvinyl morpholone (morpholinone), vinyl sulfonic acid polymers and copolymers, polyacrylate, polyacrylamide, and polyvinyl pyridine, and the like. In one embodiment, the absorbent material is a high-absorbent material. In this use of "high-absorbent material" can be the fluid and absorb a large amount of swelling to form a hydrated gel (i.e., hydrogel) polymer material. Other than in addition to absorbing a large number of fluids, superabsorbent material can also be at an appropriate pressure to retain its in vivo significant amount of fluid.

Highly absorbent material is generally divided into three categories: the starch graft copolymer, cross-linked carboxymethyl cellulose derivatives, and modified hydrophilic polyacrylic ester. Examples of such absorbing material comprising hydrolyzed starch-acrylonitrile graft copolymer, neutralized starch-acrylic acid graft copolymers, saponified acrylate-vinyl acetate copolymer, hydrolyzed acrylonitrile copolymer or acrylamide copolymer, modified cross-linked polyvinyl alcohol, of a self-cross-linked polyacrylic acid, cross-linked polyacrylic acid salt, carboxylated cellulose, and neutralization of crosslinked isobutylene-maleic anhydride copolymer.

High-absorbent material can be purchased on market, for example, purchased from Portsmouth, polyacrylate of Virginia. These high-superabsorbent polymer with various size, shape, and absorbent can (with tradenames IM   3500 and IM   3900 purchased from Clariant). Other high-absorbent material in order to trade mark SANWET (by Sanyo   Kasei   Kogyo   Kabushiki   Kaisha offers), and SXM77 (by Stockhausen, Greensboro, North provide   Carolina) market. Other high absorbent material described in U.S. Patent No. 4,160,059, U.S. Patent No. 4,676,784, U.S. Patent No. 4,673,402, U.S. Patent No. 5,002,814, U.S. Patent No. 5,057,166, U.S. Patent No. 4,102,340, and U.S. Patent No. 4,818,598, introduced in this clear all literature as a reference. The introduction of high-absorbent material described in the U.S products, such as diapers. Patent No. 3,699,103 and U.S. Patent No. 3,670,731.

For the high product absorbent material comprises high absorptive particles and high-absorbent fibers.

In one embodiment, the product including the relatively slow product manufacturing purpose of swelling and still at an acceptable rate without swelling the contrary influence the product or include a product of any of the absorption characteristics of the structure of high-absorbent material. Generally the smaller lower absorbing material, the material absorbs liquid more rapidly.

In another aspect of the invention, to provide a method for binding cellulose fiber product. Can be formed by extrusion process form a bond cellulose fiber product.

Normal circumstances, the method of which the product is formed in the forming apparatus to provide product. Generally, as the fiber pulp slurry (i.e., the fiber dispersion in the dispersion medium) introduction apparatus. Pulp slurry can include the drying of pulp, paper pulp drying from the, treated pulp, or mixtures thereof. Pulp slurry having a relatively high consistency can be, for example, in one embodiment about 15 to about 50 wt % solid, and in another embodiment about 20-about 35 wt % solid. Can then be introduced into the mixing/extruding equipment combined with other components of the paper pulp. In the apparatus for the do not include the introduction of cross-linking agent treated pulp embodiment, these component comprises a cross-linking agent and (if necessary) a crosslinking catalyst. For the embodiment of the present invention of the adhesive, the adhesive can be added to the in the equipment in the pulp slurry. The surface active agent can also be added to the air and in the paper pulp in the apparatus to provide the foam forming medium. If necessary can add other components, such as absorbing material in order to provide the required products.

The components of the product in combination with the apparatus and mixed and then extruded from the apparatus. Then dry extruded cellulose material and final product is formed by heat treatment. The product has the favorable low-density, low to about 0.02g/cm³. Normal circumstances, the density of the product is about 0.02-about 0.20g/cm³.

As mentioned above, is formed through the following way the product of the present invention: will include cross-linking agent and for (if necessary) and a crosslinking catalyst (such as including) adhesive treated cellulose fiber web is subjected to sufficient for a cross-linked (i.e. solidify) and fiber bonding temperature and time. Can be formed by several kind of method to provide cross-linking agent of the product for solidification. Cross-linking typically requires a relatively high temperature (the 180 [...]) and a long reaction time (more than 4 minutes). In one embodiment, is heated in the curing oven of the products are formed, in which the high temperature and large volume air through the network. In another embodiment, curing takes place in the network has been put into the box after used for the transport. In this embodiment, including processing of the web passing through the dryer box (such as, the kiln dryer) to complete the cross-linking reaction.

The product of this invention can be formed as a mesh or sheet, it has to allow web is rolled, transfer, and in order to roll form for subsequent the structural integrity of the process and strength.

The product of this invention can be fiber rolled form and easily into the subsequent process. Product can advantageously be introduced into every kind of absorbent article, such as a diaper, include disposable diapers and shorts; female care products, including a sanitary napkin, tampon, and a pair of pants liner; adult incontinence products; toweling ; surgical and dental sponge; bandage ; tray pad such as food.

In one embodiment, the method of the present invention provides includes intrafiber cross-linking fiber and to obtain composite material improved performance of the crosslinked fibers between fibers bonded composite material. As mentioned above, the method is foam forming method, which can make in the high solids content (i.e., high consistency) forming the composite material and do not need to use the form a wire and draining. In the method, the air content and the density of the foam in the method are the characteristics of the foam. Foam can be divided into stable or unstable. However, generally, the foam is a thermodynamically relatively unstable. The foam stability is dependent on many factors, including the surfactant type and concentration, temperature, concentration of the stabilizing agent, and the presence of the solid. When the foam by gravity of the liquid at the bottom of the mobile to the foam bubbles collapse in the foam generation, caused by the air bubbles between the top of the thin layer or the deterioration point. Refer to, Porter,   of Surfactants M.R.Handbood, paragraph 2 Edition, Blackie   Academic   &   Professional (Chapman & Hall), 1994, 65-69 page. In the process of this invention, that of the foam is stable.

For method for further understanding of the foam, the foam air content and the density of the foam is indefinitely prolonging our discussions illustrative.

Taught Wiggins-Teape according to the volume air content of at least 65% of the foam (refer to, U.S. Patent Nos. 3,716,449 and 3,938,782). For dispersion, according to the air content of the foam volume is 55-75% (refer to, U.S. Patent No. 3,817,952) or according to the volume 50-70% (refer to, U.S. Patent No. 3,937,273). Other than in the air content range (higher or lower), solid foam, such as glass fibers, cellulose fibers, particles, agglomerated. However, from the same solid content of more aqueous slurry preparation of handmade paper network or provide greater dispersion. According to the volume is described using Ahlstrom 25-75% improved method for air content (refer to, U.S. Patent No. 5,904,809).

However, in the has high content (such as, according to the volume is greater than about 75%)lower, viscosity rise of the foam described Wiggins-Teape to which the liquid in the bubble is no longer discharged from the mixture (within a reasonable period of time) of the point (such as, the foam is a stable foam). Therefore, the formation of the porous carrier, and discharge the liquid from the network, such as on a paper machine, is not practical. In the method of the present invention, high air content of the foam is a performance such as semi-solid stable foam that has liquid discharge slowly. Because less liquid can be discharged from the foam (for example, in according to the volume 95% air contents, 1000 ml foam contains only 50 ml liquid), the liquid foam collapse caused by movement (due to the gravity or suction) needs a long period of time. The overall discharge time according to the index rate is exhibited, as shown in Figure 1. In fact, never reaches complete liquid discharge. Therefore, the long discharge time and foam of stiffness or high viscosity so that the normal discharge is not practical. The method of the present invention has high content of the foam, by volume, typically greater than about 75%. In one embodiment, is greater than the air content by volume of about 90%, and in another embodiment, according to the volume is greater than about 98%. Previously does not implement this has high content does not require foam in order to produce the product of a porous carrier, through the carrier free liquid discharged from the network. In the method of the invention, foam collapse by the temperature and/or in the system caused by the absorbent material, the absorbent material absorbs sufficient to cause the foam bubble collapse of the liquid.

The density of the foam is closely related with the air content. In the above-mentioned reference documents, describe in 1 bar pressure range is 250-500g/l, the foam density. By eliminating the need of liquid discharged, lower the density of the foam can be used for forming the web (for example, about 20-about 100 g/l of the density of the foam is obtained according to the volume of about 90 to about 98% of the air content). In the present invention, in the 1 under Pakistan approximately 20-about 200 g/l foam density is useful. Process step of forming in the elimination of the need to greatly reduce the apparatus. Because during the formation of the web from the foaming material is discharged liquid, there is no typical white liquor or regenerating liquid or foam need to be re-processed and re-use. Reduced liquid/foam load also reduces the quantity of the liquid in the product, resulting in a more economic drying. This from the examination process for forming solid or consistency in the description.

Ahlstrom Patent describes the use of consistency up to 12% of the foam forming the fibers of a method in accordance with the volume of the air content 25-75% of the foam is possible. According to the method of the invention uses a volume of about 15 to about 50% fiber consistency. In certain embodiments, fiber consistency of about 30-about 50%. In other embodiments, fiber consistency of about 20-about 35%. The consistency can be achieved under such a high fiber dehydration. The extruder can be sliding auxiliary is added into the high solid fiber sludge further dehydration. Similarly, the in the high consistency of the sliding additive extrusion regenerated fiber in order to regenerate the typically found in the printed paper fiber and filler. In the method of the invention, the foam used for fluidized fiber, and adding the sliding additive on the contrary. The or co-rotating extruder is complete, the high speed screw or rotary mixer/foaming machine of appropriate high-speed rotor of the pump is the role of the surface active agent to produce the foam. For process the foam includes a surfactant. The suitable surface active agent is about 0.01-about 5 wt % surfactant concentration of the composite material, produce about 100 g/l the density of the foam is about 90% air content of a surfactant. In one embodiment, the surface active agent is the production of Croda Incronam   30.

High solid fiber is used for the method of the present invention. High solid fiber can be from the has been dewatered to greater than about 20% from the consistency of the wet pulp or through the hammer mill to obtain dry fiber and adding water production. Therefore, in the method of the invention, in the can in the mixing device for mixing and foaming high solid composition, with the appropriate chemical additives, including the binder, latex, wet strengthening agent, dry strength agent, cross-linking agent, acid, alkali, dye, powder, pigment, polymer.

The method of the present invention use is made of foam by fluidizing a high consistency fiber. Representative method of the present invention the total picture of Figure 2.

Can be made of shear inducing mixing apparatus to achieve foaming and mixing operation. In one embodiment, shear inducing mixing device is a mixer/foaming machine, for example, purchased from E.T.Oakes Corporation, Hauppauge, the type NY 8M mixer/foaming machine. This apparatus is a rotary mixer and see Figure 3A-C. As fluidized fiber, adopts the plunger piston will be approximately in the 30% solid fiber is added in the device, plunger to the rotor to promote fiber. Where the fibers contact the shear or mixing point of the rotor, into the surface active agent. Foamed fiber to leave the mould feeding pipe. See Figure 3A-C, radially of the rotor can also be added to the air and other chemicals. The front of the rotor can be in the rear surface or surfaces of the added chemicals. In Figure the rotor and the stator 3B and C. In the apparatus, the fiber must be through the channels are curved, and there is no appropriate foaming lower, fiber blocking rotor. Representative plate mixer extruding apparatus, method, according to the invention form a representative product, and the operating characteristics of the representative product described in embodiment 2.

In another embodiment, the shear inducing mixing equipment is extrusion equipment. One such extruder is a ZSK   58, bought from Coperion   Corporation, Ramsey   NY superbank mixing machine. One possible configuration of the extruder in Figure 4. In the process, at about 20-about 40% solid lower, the pulp is added to the extruder. Then adding a surface active agent in order to initiate foaming. Furthermore, the foaming is added downstream of the chemicals, but can be added prior to the foaming. Cross-linking agent, (such as citric acid and catalyst) can be added and mixed in an extruder with fibers, used for the preparation of the fiber during the subsequent drying of the product cross-linked. KYMENE can also be used as binder (purchased from Hercules, Wilmington   DE) and latex (purchased from DuPont, Midland   mi or HB Fuller,   MN St.Paul). Can be added as a solid, liquid, or gas form of chemicals and other binder. If the need to increase the foaming and/or the air content of the air, can also be included. Representative double-screw extruder, method, according to the invention form a representative product, and the operating characteristics of the representative product described in embodiment 1.

The use of any apparatus, (i.e., rotary mixer or twin-screw extruder), the foamed fiber and additive to extrusion through the die formed slice or composite screen. Also can generate other shapes. The foam composite material extrusion to the solid on a conveyor belt, wire, non-woven carrier fabric at the network transmission to the dryer. Then use techniques such as convection drying, through air drying, collision, microwave, radio frequency, and the like, drying (and/or optionally cured) foamed composite material.

By the method of the invention comprises a composite material formed of composite material collection and storage. The method of the present invention enable the formation of the by any fiber composite material, the composite material has a low density, and includes in situ cross-linking fiber composite material. In-situ cross-linking fibers in a composite material, the fiber is added before the extruder in the cross-linking agent is added to the fiber. Or, during the extrusion process can be a crosslinking agent is added to the mixing device.

In order to achieve the appropriate collection performance, collecting composite material having a relatively low density. Collection composite material also has appropriate-absorbing characteristic, in this known as the mid-point of the desorption pressure (MDP).

As shown in Figure 5, the production by the method of the invention more less than the density of the composite material by the other method for forming composite material. Figure 5 shows that in the method of the invention and the two types of fiber of the difference between the method of batching. Can be typically at about 0.14g/cm³ lower, described in the following literature the cellulose composite material the formation of the foam process of producing only a loose: PCT/US99/26560, reticulated absorbent composite material, and PCT/US99/05997, method of the composite material of the groove is formed. In the traditional papermaking fibers in the wet-laid system, depending on the grade density can be 0.1-1.4g/cm³ (refer to K.Britt pulp and paper technical manuals, 1970,669 page). The method of the invention can be from the same fiber (loose) in 0.037g/cm³ formed under the density of the composite material. The density of a density of less than this, in the latter a the lower foam density, or high dilution wet-laid process can be formed of composite material including cross-linked fibers.

Density distribution associated with the flammability. The method of the present invention, agglomeration of the foam on the nature and effect of the two dispersion effect, produces a net wide Kong Du range. By measuring and kong Duji flammability from the foam metallographs the measured value received confirmation. Less than 750 the flammability of   m can be easily distributed by the purchased from TRI/Princeton, Princeton, NJ automatic kong Duji measurement. In theory, application, and the description of the apparatus, refer to Miller and Tyomkin   Science Journal   Interface   of Colloid   and the (162,163-170 page, 1994). kong Duji through absorbing and desorbing cycle test sample. Simply, the presaturation of the sample into the instrument. Increase the pressure in the sample chamber, caused by the liquid in the first sample from the largest hole subsequently discharged by a small hole. Is connected with the balance interface in each computer monitoring of the pressure exerted from the sample liquid quantity. After the test the final pressure, the contrary operation of the system, cause the sample absorption liquid, again by the pressure of the tracking. From the data, the hole distribution can be determined and absorption/desorption lag.

Method for preparing by a mode radius of flammability similar net , µm, see table 1. For mode definition has the flammability of the volume of, indication of the highest frequency. These value indicating the extrusion method by the present invention in the composite material formed of a pattern hole degrees (from flammability of the maximum volume) is larger than those of the other production method.

Table 1. Mode method for comparing the radius of flammability (µm) extruding a foam air into the absorption curve- net aqueous method   330     225     210     250 desorption curve   150     88     98     75

The data in the above table from Figure 6-9 flammability of the distribution map is shown. Figure 6-9 described by the invention of an extrusion process, respectively, of the foam forming method, air into a net, and wet-laid process to form a representation of the distribution map flammability of the composite material. Each kind of composite material based on the weight of the goal of 300g/m². In these Figure, indicating absorption of flammability mode. Mark has been de-suction mode, but can be determined as such as absorption.

Capillary desorption pressure (CDP) to the low value is preferably had been instructed to collect composite material. Capillary desorption pressure (CDP) is defined as the pressure head, the pressure head in the saturation in the sample under 50% liquid has been discharged from the sample. Collecting the fluid, 8-40cm   H₂ O (general 8-25cm   H₂ O) capillary desorption pressure value for the synthetic foam is beneficial to collect fluid (refer to, e.g., U.S. Patent No. 5,571,849, U.S. Patent No. 5,550,167, U.S. Patent No. 5,851,648). Distribution of the fluid, the CDP 12-50cm   H₂ O (general 20-40cm   H₂ O) value that is required for good performance of the (refer to U.S. Patent No. 6,013,589).

As mentioned above, and Miller Tyomkin display can be determined from the following map capillary desorption pressure: obtained from automatic kong Duji the percentage of saturation of the graph of the pressure exerted. The absorption of the pressure range (intake) reconciliation suction (retaining) the collection and retention material curve to obtain an indication of liquid capacity. For use in absorbent products, such as baby diapers collection material must be able to rapidly absorb liquid and is also effective to release it again in urine cloth wick. By the automatic kong Duji measuring capillary desorption pressure known as the mid-point of the desorption pressure (MDP). MDP can be used as the material as a measure of the ability of the collection material. It is clear that any saturated and percentage can be selected (for simple) the inflection point of the curve when it is close to the mid-point of the selected curve. In addition to the material formed by the method of the invention outside, non-cellulosic material can not just to reach less than 14 cm   H₂ O of the value MDP. Therefore, display more low-MDP value of the cellulose material of the collection of the lead to improved performance.

In one embodiment, the composite material of the present invention is less than about the value MDP 14 cm H₂ O. In another embodiment, composite material of less than about the value MDP 12 cm   H₂ O. In a further embodiment, the composite material is less than about MDP 10 cm   H₂ O.

Cellulose-based collection to the current performance of the material, taking into account how a long by the United States air-laying fibers collecting material. Automatic TRI kong Duji use, the MDP 44 cm H₂ O. The data in fig. 10 to display the display in the output of the automatic kong Duji.

Cross-linked cellulose fibers in the personal care absorbent products, such as baby diapers the use of the improved performance of the diaper on the market. Test from the two kind of cross-linked fiber preparation of MDP air-laid pad. From citric acid cross-linked fiber (chemical B) preparation of the liner of the MDP 24.2 cm H₂ O. Selected from polyacrylic acid/citric acid cross-linked fiber (chemical A) preparation of the liner of the MDP 14.4-15.9 cm   H₂ O. Chemical C relates to a polypropylene acid cross-linked fiber.

The method of the present invention to provide the network with improved MDP values. For example, the Oakes mixer/foaming machine without the use of cross-linked chemical and form the extrusion engelm web provides 18.5 cm   H₂ O of the value MDP (compared with the air of the wire forming methods 44 cm   H₂ O). A total of from the polyacrylic acid and citric acid fiber mixes crossing linking (pre-cross linking chemical A) form of MDP value of the measure to the dirt 10.5 cm   H₂ O (compared with air of the wire forming methods 15.2 cm   H₂ O). From citric acid cross-linked fiber formed (pre-cross linking chemical B) of the dirt of the MDP values 12.0 cm   H₂ O (compared with air of the wire forming methods 24.2 cm   H₂ O).

Because the net structure and the surface tension effect extrusion process provides improved MDP. Related to the surface tension of the pressure difference, such as represented by the Laplace equation: γ=2σΔPcos[!theta!]

Wherein ΔP = differential pressure, σ = surface tension, contact angle θ =, and r= radius.

If the presence of the surface active agent for reducing surface tension (such as in this invention as foam extrusion process), under the constant radius, must also reduce the pressure difference (in fact MDP). But unless anti-collapse, most hole collapse when wet. Cross-linking can be increased through the fiber between the bonding and in the structure and/or binder be further improved. If adhesive and fiber resilience increase, the hole radius will not collapse, once again receive lower MDP value (the avalanche hole radius and minimizing the increase in pressure). The addition of the latex is increased and so to reduce the contact angle value of the cosine. This is also a constant radius for the reducing of the MDP.

The above-mentioned improvement in Figure 11 and 12 in said representation. Fig. 11 is a display for the method of the invention as a cross-linking chemical function the mid-point of the reducing of the desorption pressure. From the loose fiber, citric acid cross-linked fiber, and in-situ citric acid cross-linked fiber (i.e., processed is added to the mixing device but not using citric acid-curable fiber) form the extrusion of the composite material of the numerical value to the MDP 18.5, 12.0, and 9.8 cm   H₂ O. Fig. 12 is a display for including the use of polyacrylic acid and citric acid a total fiber mixes crossing linking (pre-cross linking chemical A), citric acid cross-linked fiber (pre-cross linking chemical B), in-situ citric acid cross-linked fiber (in-situ chemical B) and in-situ polyacrylic acid cross-linked fiber (in-situ chemical C) extrusion composite material, the effect of the MDP [...]. When the [...] number, from these fiber preparation of the composite material of the value MDP is reduced. The reducing of the MDP (from 12 to 9.8 cm   H₂ O) by the dashed-line display, compared with the cross-linked chemical B solid-line. Chemical C display even greater MDP reduced.

Latex, such as purchased from HB   Fuller, the adding of   MN St.Paul, (such as based on composite material of the total weight of 5 wt %)is also positively influence the collection performance and improved MDP. Figure 13 shows that single latex and with in situ cross-linking of the latex reduce MDP. Again, consider the digital-linked in situ cross-linking effect display divert compared with the (previously displayed as 12 to 9.8 cm   H₂ O). No in-situ cross-linked latex effect is 12 to 9.5 cm   H₂ O in the MDP. In-situ crosslinking and latex added to the combination effect from MDP 9.8 into 8.3 cm   H₂ O. In the higher level of the latex, to obtain even lower MDP value. As an example, containing 15% of the latex chemical crosslinks A of the fiber composite material is MDP 7.7 cm   H₂ O. Summing up the values of the MDP table 2 provide in.

Table 2. Representative value MDP extruded composite material

^* apply only to the cross-linked fiber

(E) in a double-screw extruder = preparation of the sample

(O) = Oakes mixer/foaming machine the preparation of the sample

= (E & O) included in the Oakes mixer/foaming machine or double-screw extruder of the sample preparation

The measurement according to the present invention forms the collection rate of the extruded composite material. As in the U.S. Patent No. 5,460,622 and U.S. Patent No. 4,486,167 measured in the collection rate, is introduced into each of the patents in this as a reference. The only change is to the procedure using 75 ml total load close to the pouring out of the total capacity of the diaper, make the test more strictly.

The purchased commercial diaper (Procter PAMPERS of the   &   Gamble) and by indicating program test section 4-discharge collection rate. Commercial diaper to 75 ml of the 4th-discharge display 0.44 ml/sec and collect the speed. This performance said the current technical level. The use of chemical B (citric acid cross-linked fiber) and C (polyacrylic acid cross-linked fiber) in 4 and 6% cross-linked in situ production of the collection patch. These patch is then inserted into the commercial diaper (and controls the same size and type of PAMPERS). Inserted into the completed as follows. The covering material of the diaper a careful cutting and rearward end of the strip in order to show the commercial collection patch and carrier tissue. Carefully remove these materials, but does not disrupt the diaper core. The commercial patch of the same size of the representative extrusion patch is inserted into the diaper. The covering material to return to the original position and sealing.

In 4% cross-linking agent level, depending on the chemical type, section 4-discharge collection rate is 0.48-1.13 ml/s. The object as the 2nd, also test-linked fiber. In the 6% level, depending on the basis weight and the chemical type, speed is 0.36-1.60 ml/s. These data show the object relative to the commercial diaper from and relative to the cross-linked fiber production collection material, extruding a composite material significant improvement of collection rate. The crotch area of the diaper is reduced, thus reducing can be used to collect the area of, the improvement is of special importance. The collection of data in table 3.

Table 3. Representation of the collection rate of the extruded composite material

Extruded composite material of this invention also display favourable tensile strength. Since many test sample is very weak (such as air-laying loose cushioning), the situation for measuring tensile stretching method. Method for extending the use of fixed to the constant rate of drawing machine such as those provided by the Instron crosshead under the horizontal clamp. The 10 cm × 10 cm sample clamping into the clamp. For each sample the load cell zero. Then pull the sample by the stretching machine. Machine to measure each sample elongation and breaking load.

Adopts two different kinds of chemical and in three horizontal lower production in situ cross-linking of the sample. These sample tensile data as shown in table, and a map. It is clear that when the in-situ chemical [...] increases, tensile increase. This increase is an indication of increased bonding between fibers. All of the sample (except for those indicated as the cross-linked) production in the same way, only in the change table 4 chemical type and shown in horizontal.

Table 4. Representative the tensile strength of extruded composite material

Based on fiber weight level; using the Oakes mixer/foaming machine extruding all of the sample.

Depends on the application of the cross-linked chemical, when the stretch increase in-situ cross linking 10-20X. Figure 14 the in-situ cross linking by the effect of the tensile strength of the composite material.

Latex can be used for increasing the strength of the extruded composite structure with net. Latex and fiber blend to the representative extrusion composite material strength effect see Figure 15. Latex and cross-linked chemical to the representative extrusion composite material strength effect see Figure 16. The reference Figure 15 and 16, using 6% chemical chemical B strength of a specimen is 34g/in (BW=205gsm). Using 5% latex of chemical crosslinks composite material is B 94g/in (BW=157gsm). Using 5% latex and 6% in-situ crosslinking of the composite material of the stretch being 1065g/in (208gsm), the process of large than either a separate more than ten times.

In a further aspect, the present invention provides includes crosslinked cellulosic fibers of the absorbent article products. Product can be with one or more other layer in order to provide for the introduction of absorbing products such as baby diapers, adult incontinence products, and female nursing the structure of the product. Embodiment embodiment 1 representativetwin-screw extruding apparatus and method, and representative products and their performance characteristics

In this embodiment, twin-screw extrusion equipment described representative, products formed using the same method, the method of using the apparatus to form a representation of the product, and representative performance characteristics of the product.

Laboratory testing the foam medium in the possibility of providing enhanced performance of the fiber. Consider successfully to the laboratory, a pilot-scale test. The following description of use in the methods of the invention by Krupp, Werner, and Pfleiderer (& P KW) production twin-screw extrusion machine to provide the representative product of the present invention.

In the experiment, a broad range of basic weight (-400-2000g/m²) continual net of the extrusion material. The bi-component fiber (CELBOND   T105) is added to the system in order to produce a stronger in the sample integrity. The surfactant concentration in the two level: of the total mass of the 1% and 0.5% the test. Two horizontal generate an appropriate foam. Similar foam quality from those of the Oakes laboratory unit (plate mixer/foaming machine, 94-99% air content, the density of the foam is 10-60g/l). On the fiber length, does not damage the fiber of the fiber. The quality and performance of the product is not optimized, the Oakes can be satisfactorily as a sample of preparing system. Extruder unit is close, and depends on the diameter of the screw, can be installed on the concrete slab without a foot or pile foundation. Compared with the typical paper industry, small size and process simple also into low-capital and engineering cost. Directly to the equipment in order to dry is added in the form of the ability of SAP.

Equipment. The use of nine barrel ZSK   58 mm twin-screw extruder (KW & P) used for the test. Extruder set the chart sees the chart 4. Four Acrison single screw feeder is used for addition of raw material in the extruder. Total five different screw design used for dispersing the fiber and generate foam. Different screw design described in the following parts.

Figure 4 shows the device displaying the characteristics of several noteworthy. 1st characterized in that the relative sizes of the equipment. Extruder contains about 25 the   × 25 the regional [...]. Extrusion machine in host 2nd and on the floor on the floor of the feeder. Each barrel is less than 1 ft-long. In absorbent products in a commercial design, does not need to be nine barrel system (note: from the left count, 1st and finally a machine barrel is not necessary). 3rd of a machine barrel is also optional.

Another one is to simplify important spot. This system is basically builds up into , the operation of the assembly the. The feeding system is simple, with known technology: weight loss feeder. When the absorbent material (such as high-absorbent polymer, SAP) can adopt a dry form by directly adding the wet fiber stream side feeding machine without blocked, emphasize this point. This system can easily processed fiber and meet the most first SAP two test purposes. SAP proper in order to dry the process to maintain the form of the swelling SAP SR1001 (bought from Stockhausen of minor cross-linked polyacrylate) minimum situation. When the drying by adding and retention time in the extruder in 5 seconds the following, another kind of polypropylene ester from Stockhausen, SXM-77, soluble and bulge adversely affect operability.

Test details. A series of operation of the extruding machine test. These run the see table 7. No fiber, foamed no problem, for generating foam 96-97% air content range (compared with the described in the following literature foam forming process (froth Cheng Wang) theoretical optimum 67% : PCT/US99/26560, reticulated absorbent composite material, and PCT/US99/05997, forms the groove method of composite material, each Patent in that a full-text clearly introduce as a reference). Is the density of the foam 29-30g/l, compared with the foam-laid process typically 350 g/l. Foam after the, start fiber feed. In order to obtain the fiber dispersion is, trying to three different screw configuration. 1st kind of configuration has a considerable number of high shear element. Although these elements generate shear, they also limit the flow of the material (such as increased retention time). This design produce some heat and can not be effectively dispersed fiber. 2nd design, there is no restriction on the low shear design. This design can achieve 1000rpm screw speed and is not significantly increased temperature. As a result, improved fiber dispersion. textile fiber knot in the network is still visible. However, screw 1st disperse better in this test design and better than in the dispersion of the reached, this test the following identified as 1051-XNP.

3rd design re-insert a limited number of more high shear element in order to improve the fibrosis. These less shearing element for increasing the temperature.

4th screw design (similar to 2nd kind of design but using more kneading section) allow up to 225 pounds OD fiber/hr (2.5 tons/day) of the feeding. Processing the fiber only, the display design the screw to break the fiber block. Reducing the feed to 0.5 ton/day can be more easily see the fiber dispersion. Then install the slit die, it produces approximately 500g/m² and 0.05g/cc (26.6% solid (couch) "lieth") network.

In the sample and machine data, in about 50% level by adding SR1001. Side feeder operation of feeding problem of complete and no SAP. The composite material (BW-1100g/m², density -0.11g/cc) through the die head for extrusion and sample (39% "lieth" solid). Capacity value is 16g/g. When the attempt to SXM-77 time, remove all the free water and produce SAP and fiber drying block. This is in the previous test (1050-XNP) the same results seen in.

Because the network can adopt mold production, SAP on the weight basis of the production of the sample to the previous preparation and testing of a foam-laid material. CELBOND bi-component fiber to   T105 in order to increase the integrity. In the system can also be adding the wet strengthening agent KYMENE, the bi-component fiber. A low basis weight of the material. Surfactant from 1% of the total mass of the reduced to 0.5% without adverse effect. Experience, water availability than the total amount of surface active agent is more restrictive factors.

The screw design using some 5th sail element is formed containing and no CELBOND   T105 other low basis weight material. Material display with less junction. Study to yield, it is determined that the screw limiting fiber feed to 700 pounds/hr (the status quo so) or about 1170 pounds per hour total mass (assumed 40% solid and 50% SAP).

Fiber quality/dispersion results: screw design and production. Several of the design of the screw shaft the material of the junction and percentage of the sample of the fiber length. These two test typically composed of a small laboratory material in order to evaluate the efficiency of use. These tool for the evaluation of different screw design. According to the acoustic wave hierarchical data, table 5 indicating design 5 slightly better than design 4. In either design, has not cut the fiber, such as that of a fiber length data.

Table 5. The design of the screw 4 and 5 compare the fiber quality

Other data indicating the design 2 is small and the efficiency of the subsequent design improvement fiber dispersion.

Solid content. The solid percentage 25-65% measuring range, but does not follow the predicted value according to the material balance (17-47% range). All except one measurement value indicates higher than theoretical value of solid, it has not been fully dried sample may be instructions.

Capacity as a result. The 37-46% SAP content of the sample measuring approximately 11-17g/g the capacity of the load under the number value. Consider high basis weight and the size of the die slit constant and increase the density, capacity value is reasonable.

Surfactant active level. The use of the three surface active agent (bought Incronam 30 of Croda) level is 5.0, 7.5 and 10.0 (the status quo so) pounds/hr. The surface tension value from the water extract indicating surface active agent exists on the surface and is easy to remove. The level of the three surface active agent (5.0, 7.5 and 10.0 pounds/hr) is surface tension value 40.7, 40.4, and 35.5 dynes/cm. As the foaming in all horizontal is successful and in the process is not in the "washing" step, can adopt low level of surface active agent in order to reduce the level of residual surfactant. More low levels of surfactant to collect the characteristic of the product can be enhanced. The use of the foam web forming Incronam the network   30 or Dehyton   K is the typical extract surface tension value 40-43 dynes/cm.

In distribution/collection/flammability value more than the suction pressure. The method for testing Edana, new market pulp standard measurement collection. For 100 ml dose of the 1st to the 3rd, the   &   Gamble PAMPERS Procter of the collection time is 27 seconds, 60 seconds, and 85 seconds. Representative performance indicating collection of sample the presence of excess surfactant. For all sample collection time is 1st dose 30-70 seconds. Normal circumstances, 2nd and 3rd dose time consuming and is longer than 300 seconds (5 minutes).

The diagram gives representative of the product in the distribution and the flammability value more than the suction pressure.

Flammability (PSD) distribution (MDP) and the suction pressure value more than the surfactant active level does not go beyond on the collection performance insight other. The above chart 17-20 display in this test two production during more low basis weight of the sample and PSD MDP. When the and Figure 21 and 22 when compared to the, 1051-XNP sample is very similar to the embodiment of the the Oakes 2 production during said laboratory study of those. MDP the two data do not show any differences between study. Operation 17 and 19 respectively of the value MDP 17.2 cm   H₂ O and 16.2 cm   H₂ O, Oakes process in the 100% value is loosen 16.5 cm   H₂ O.

And similar comparison of the foam-laid material. In the following table 6 display according to the present invention with respect to the foam web forming the material of the comparison material prepared. Prominent difference is the vertical wicking density and to obtain the effect. Although wooden fabric pulp (long red the United States) have different content, similar to the capacity value. Even without optimization, 1051-XNP material can achieve the foam-laid the prepared material.

Table 6.1051-XNP and foam-laid (943 and 946) comparison of the sample

Yield. Research instruction can be output through the 58 mm machine processing -450   OD-pound/hour (5 tons/day) of the total mass.

Table 7. A SUMMARY of representative extrusion composite material

Embodiment 2

Representative plate mixer extruding apparatus and method, and representative products and their performance characteristics

In this embodiment, extrusion equipment described representative plate mixer, the product is formed using the same method, the method of using the apparatus to form a representation of the product, and representative performance characteristics of the product.

Plate mixer/extrusion process is the material used for preparing the core of the traditional forming technology of an alternative. In this embodiment, Oakes mixer/foaming machine (Oakes continuous mixing head, E.T.Oakes   Corporation, Hauppauge, NY) is used for generating an extruding a foam, from the foam by a simple die head by extrusion prepares the net. Use of three fiber armaturen: the United States long red pulp fiber (CPine), citric acid treated cellulose fiber (XLA), and these two kinds of fiber of the 50 [...] 50 blend. Purchased from the   Company H.B.Fuller PD8161 latex, in order to 5 wt %, 10 wt %, and 15 wt % as bonding and resilience of the level of compounding chemicals.

The terminology used here that "EXPRO" and extrusion process of the present invention, the product that is formed by the technique.

Results show the following. The apparatus and method may be lower than other prior art in the density of the loose fibers and treated fiber form. The average of these products via traditional flammability to the radius of the dirt to form a larger network. Compared with the existing material product has improved information-gathering. Compared with the products formed by the traditional process of the current material in the display to be more low value more than the suction pressure. Extrusion process with raw materials or the minimum waste of the product.

Overview. In this embodiment, CPine, XLA, and PD8161 latex for the formed with different fiber ingredients and latex content of the sample. Sample description table 8.

Table 8. Extrusion composite sample description

Oakes setting. For the production of these sample, as shown in Figure to use 3A-C laboratory equipment shown. Specific machine and operating requirements given below.

Normal circumstances, in the 30% of the required consistency of pulp fiber, and 2 wt % Polyox as a sliding aid (4 million molecular weight poly-ethylene oxide) is added to the feeder through the plunger together with a mixer/foaming machine. Feeder through the plunger the other additive such as air, surface active agent and latex in place on the apparatus to the inlet of the Oakes. The present system is a batch operation system, the builds up into , the build-up on the basis of the basic operation no waste. By paper pulp feed rate and the conveyor speed control sample target basis weight (300g/m²).

Distribution of flammability. Automatic TRI kong Duji measuring the distribution of flammability. In this discussion a few examples. In this selected three sample representative of the three ingredients of the difference in: engelm (embodiment 2, Figure 23), XLA (embodiment 6, Figure 24), and the 50 [...] 50 blend (example 10, fig. 25).

In Figure 24 in, attention to the curve of each curved more high average radius of the transition. This is slack the indication of the change to the cross-linked fiber. Figure 25, blend sample, display in Figure 23 and 24 between those seen in middle mode value. Greater average radius is formed more loose net more hard-crosslinked fibers and also as the result of the support structure. The following area of the curve is an indication of the total volume in the sample, is an indication of the capacity of the sample. This is based on the following facts: PSD curve is obtained from the automatic kong Duji derivatives of cumulative volume chart. According to their flammability can be therefore the impact evaluation of the fiber ingredient, also influence the flammability or the volume of the volume of the structure.

However, on the collection, flammability preferably only comparison process according to the mode. Such values as listed in table 1. These numerical instructions extrusion process of the present invention producing four kinds of the maximum flammability testing process.

Collection. Collecting performance is typically based on multi-dose the results of the test. 4th-discharge as a result, is the most strict conditions, are commonly used as an indicator of performance. The study of the sample in the 4th-discharge results see table 9 summarized in the table.

Normal circumstances, is the most promising XLA of the results. These results in Figure 26 gives in. These data show the control relative to the current diaper, collection rate by a separate XLA improved. When the latex is present, relative to the control result and to continue 1012-XNP improved the performance of a. 4th-discharge result is not only improved. All of the-discharge (1-4) display to improving the collection rate of the object.

In value more than the suction pressure. Although for collecting material is quickly is important to collect the fluid, the material must also be able to easily to the absorbent core from it. By this ability to release fluid in the suction pressure judgment value more than the. This is the period of the automatic flammability test meter 50% collection fluid has been removed from the sample pressure.

From citric acid crosslinked fibers of the composite material formed of approximately MDP 20-22cm   H₂ O. From the fiber composite material formed of such as XLA can reach only 16-19cm   H₂ O of the value MDP. Fig. 29 displayed for producing XLA 1012-XNP in the embodiment of the sample. In this MDP is 17 cm   H₂ O.

The use of extrusion process, formed separately from citric acid crosslinked fibers of the composite material of the value MDP 10.5 cm   H₂ O (igur 28). Latex to the MDP by adding improved 7.7 cm H₂ O (igur 27). According to the table 9 of the batching shown in MDP range of fibers, these fibers can be used, the latex and extrusion process control for the MDP 8-17cm   H₂ O.

These results show that different process in density and flammability different in the structure of the distribution. These differences in the structure, surface characteristics and, also affect absorption value more than the pressure in.

Figure 29, 30, and 31 by the three different process of the composite material formed of MDP. Figure 31 display from the identification is 46-01 and 46-02 XLA fiber preparation of the two batch of gauze pad. For the density of the secret presciption 0.06g/cm³ but does not contain any surfactant in order to inhibit MDP (14-16cm   H₂ O). Figure 29 as previously light rays penetrate the rubber head composite material formed of foam. Despite having a low density, but slightly higher than the air-laying MDP of the sample. Figure 30 shows the MDP wet-laid composite material. This material for the MDP 18.5 and has similar to the density of the foam forming the sample. As shown in Figure 27 and 28 the see, by the extrusion process to form a sample display lower MDP value.

Stretching. Stretching in accordance with the tendency of the change of the desired : (1) when the content is increased when pine , [...] ; (2) when the cross-linked fiber content increases, tension reducing; and (3) when the latex content is increased, the rope. The Instron using the horizontal clamp measuring these samples.

The results can be summarized as follows. When using loose fiber or cross-linked fibers, the dirt forming an absorption net density of which is less than other process. The radius of the dirt, the greater the average flammability, providing enhanced collection performance. Extrusion process to be able to use the loose fiber and cross-linked fiber production network with improved MDP, it indicates the material will be more easily release the liquid to in storing core. Extrusion process can be added to the latex and other additives to aminaka without spray and no waste situation.

Latex and fiber blend for the extruded composite material strength effect see Figure 15.

Table 9. Representative stretch composite material properties

^a by the air-laid/SAP mchp surrounding the test sample in Procter   PAMPERS   &   Gamble. The same commercial diaper as control.

^b select the most nearly 300g/m² used for testing of the sample. Set value of the average basis weight indicating process (fiber feed and the conveyor speed) close to an extent as to achieve the target basis weight.

^c XLA fiber (WTC)

^d XLA fiber embodiment (CMF) 3 representativeperformance characteristics of the product

In this embodiment, according to the present invention described the representation of the performance characteristics of the product.

Representative of the present invention (MUP) absorption pressure in the middle of the product, intermediate desorption pressure (MDP), and measuring calipers diameter , and compared with the conventional air form the network. Standardized results are shown in table 10. In table 10 in, expressed XLA adopts a citric acid crosslinked cellulosic fibers of the air form the network, using citric acid XLB said combination of fiber and polyacrylic acid cross-linked cellulosic fibers of the air form the network, said EXPRO-D adopts a citric acid cross-linked cellulosic fiber composite material, from EXPRO-E adopts a citric acid treated cellulose fiber product of the invention, and from the said EXPRO-F adopts a citric acid and polyacrylic acid conjugates treated cellulose fiber and latex formation product of the present invention. In 300gsm basis weight lower test all of the sample.

Table 10. Intermediate absorption pressure, intermediate desorption pressure, and calipers diameter

Representative of the present invention collect the speed of the product, and re-humidity content, and tensile strength measurement, and compared with the conventional air form the network. Standardized results are shown in table 11. In table 11 in, expressed XLA adopts a citric acid crosslinked cellulosic fibers of the air form the network, using citric acid XLB said combination of fiber and polyacrylic acid cross-linked cellulosic fibers of the air form the network, said EXPRO-D adopts a citric acid cross-linked cellulose fiber foam form the composite material, and from the said EXPRO-E adopts a citric acid treated cellulose fiber product of the present invention. In 300gsm basis weight lower test all of the sample.

Table 11. Collection rate, then humidity content, and tensile strength

Despite the illustrated and described preferred embodiments of this invention, understanding among them can carry on various changes without departing from the spirit and scope of this invention.