CN1387592A

CN1387592A - Soft, absorbent material for use in absorbent articles and process for making same

Info

Publication number: CN1387592A
Application number: CN00815375A
Authority: CN
Inventors: K·兰加查里; E·谭; S·S·哈伦; K·W·苏姆纳; D·S·瓦尼
Original assignee: Rayonier Products and Financial Services Co
Current assignee: Eam Corp
Priority date: 1999-09-03
Filing date: 2000-08-15
Publication date: 2002-12-25
Anticipated expiration: 2020-08-15
Also published as: CA2384508A1; CN1177090C; JP2003508647A; IL148199A0; MXPA02002278A; WO2001018302A1; IN2002MU00212A; EP1268914A1; TR200200537T2; CN1545992A; BR0014164A; AU6908700A

Abstract

An absorbent material (20, 300, 400, 520) is provided with improved characteristics. A process is provided for making the absorbent material. A web is formed with at least one layer of absorbent material, and it may include a mixture of cellulosic fibers (32, 532) and superabsorbent material (40, 540). The moisture content of the web is increased so as to increase the web density. Then, the web is compacted at an elevated temperature to further increase the web density and preferably to also effect hydrogen bonding within the web. In one embodiment a tissue layer (22, 522) is provided, is wetted with water, and is bonded to the layer of absorbent material.

Description

Be used for using absorbing material and manufacture method thereof in the softness of absorbent article

Technical field

The present invention relates to absorbing material and the manufacturing method as the absorbing material of the absorbent core in the goods, these goods for example are disposable diaper, feminine hygiene and incontinence device.Particularly, the present invention relates to improved absorbing material, this absorbing material is the high density with splendid absorbent properties, strong matter, flexible material.

Background technology

Have been found that disposable absorbent article, diaper for example, feminine hygiene and adult incontinence devices etc. extensively is accepted.In order more effectively to work, this absorbent article is absorb body fluids apace, with these liquid distribution in absorbent article everywhere, and can retain these body fluid, place load following time can utilize enough energy to make the body surface drying with box lunch.In addition, absorbent article should be fully soft and easily bent, so as cosily consistent with body surface, and can fit tightly, leak to reduce.

Although the design consideration purposes of single absorbent article and changing still exists some common element or parts for this goods.Absorbent article comprises liquid top flat or surface layer thoroughly, and this surface layer is designed to contact with body surface.Surface layer is made from the material that health is transferred to the core of goods basically in the clear by a kind of fluid that allows.Surface layer itself is not answered absorption fluids, and like this, it should keep dry.Goods also comprise liquid-tight tergite or the backing layer on the outer surface that is arranged on goods, and this layer is designed to prevent that fluid from leaking into outside the goods.

Being arranged between surface layer and the backing layer is absorbing component, and this absorbing component is called as absorbent core or absorbing sheet in the art.The effect of absorbent core is absorption and retains the body fluid that enters absorbent article through surface layer.Because the source of body fluid usually is local, and a kind of device preferably is provided, this device distributes a fluid in the whole dimension scope of absorbent core, so that utilize all available absorbing materials fully.It is typically or by the distribution member that is arranged between surface layer and the absorbent core is provided, and/or the one-tenth that changes absorbent core itself realization of assigning to.

Fluid is by transition zone, transport layer or be arranged on surface layer and absorbent core between catch the different piece that layer is assigned to absorbent core.Because this body surface of catching layer contiguous wearer is caught layer and should do not formed by the material that retains a large amount of fluids.The purpose of catching layer is the deflection dispersion of being convenient to fluid, and further transmits fast and distributing fluids to absorbent core.

Absorbent core typically is made of cellulose wood pulp fibres matrix, and this cellulose wood pulp fibres matrix can absorb a large amount of fluids.Absorbent core can be designed to enhance fluid absorbability and stand-up in many ways.For instance, by superabsorbent materials is arranged between the wood pulp fibre, the fluid stand-up of absorbent core strengthens greatly.In the art, superabsorbent materials is well known that, can absorb a large amount of fluids and form the water-fast basically absorbing polymeric composition of aquogel after absorbing with respect to its weight.In the art, it is known comprising the slurry and the alloy of superabsorbent thing and the absorbent article of mixture.

The distribution of the superabsorbent thing in absorbent core can be uniform or uneven.For instance, be configured to comprise the superabsorbent thing that those parts than close the surface layer or the core of catching layer have high level near the absorbent core (farthest) of backing layer apart from the wearer.By further for example, the section construction that enters the core at place (for example trapping region) near fluid becomes the peripheral part (for example storage area) that fluid transmission (wicking) is arrived core.

Except making slurry and superabsorbent materials fusion, many other methods of the performance that is used to promote slurry have been described also.For example, by utilizing the chemical Degumming agent can be easily to pulpboard defibre (referring to for example United States Patent (USP) 3930933).In addition, but the cellulose fibre of wood pulp in conjunction with flash drying before entering in the compound outer lining absorbing material (referring to the UK Patent Application GB2272916A that for example announced on June 1st, 1994).And the cellulose fibre crosslinkable of handling respectively of wood pulp is (referring to for example United States Patent (USP) 4822453; 4888093; 5190563; With 5252275).The defective of all these methods need to be wood pulp manufacturer to take time intensive, operation that expense is high in the wood pulp preparation process.Like this, use these method steps to cause the substantial increase of wood pulp cost.

Improved absorbent properties although reported all above-mentioned treatment steps, but still had some defectives relevant with this processing as the slurry of absorbent core.For instance, the manufacturer of final use absorbent article (for example feminine hygiene or diaper) obtains the wood pulp of slabbing form usually there from wood pulp manufacturer.Then, the final use product manufacturer must make the fibre pick in the wood pulp sheet, so that the single fiber of separation limit in lodicule.Usually, the slurry have the low humidity amount, this causes single fiber easily broken relatively, so since the fluffing operating process in since fiber breakage cause thin dirt.If slurry manufacturer implements this fluffing operation before being transported to the absorbent article producer, the cost of transportation of slurry increases.At least one slurry producer once attempted without the chemical Degumming agent but made the slurry that flash drying crosses and solve this problem (referring to United States Patent (USP) 5262005) in the basic weight of close limit and pulp density, yet, even adopt this method, the producer of absorbent article must still will handle this slurry after purchase.

A large amount of trials had once been done by the manufacturer of absorbing material, had the core material of high absorption, strong matter, softness with manufacturing.United States Patent (USP) 4610678 discloses a kind of airlaid material that comprises hydrophilic fibers and superabsorbent materials, and this airlaid material becomes net in the drying regime downstream, and compacting under the situation of not using any additional binding agent.Yet this material has low globality, and the danger that exists most superabsorbent materials to scatter or lose.United States Patent (USP) 5516569 discloses in the process of air lay method by the water that adds significant quantity in material can reduce scattering of superabsorbent materials in the air lay absorbent.Yet the material of generation is thickness, low-density and has high moisture (greater than about 15% percentage by weight).United States Patent (USP) 5547541 discloses by add thickening agent in material and has made the high density airlaid material that comprises hydrophilic fibers and superabsorbent materials.Yet, use this thickening agent to increase the manufacturing cost of material.

United States Patent (USP) 5562645 discloses low-density absorbing material (density is less than 0.25g/cc) and has used this low-density, discrete material to increase transportation and processing cost.United States Patent (USP) 5635239 discloses the absorbing material that comprises two kinds of synthetic forming agents, and these two kinds of synthetic forming agents react to each other to form a kind of synthetic when moistening.The synthetic forming agent is an olefin polymerization.European patent application EP 0763364 A2 discloses the absorbing material that comprises CATION and anion binding agent, and this binding agent is used for making superabsorbent materials to stay in the material admittedly.Use this forming agent and binding agent to increase the danger of making the cost of absorbing material and having brought potential environmental pollution.

United States Patent (USP) 2955641 and United States Patent (USP) 5693162 disclose (1) with vapor applications in absorbing material, to increase wet amount and (2) compressed absorbent material of absorbing material.United States Patent (USP) 5692162 also discloses and has used hot calender roll (can cotton ginning) to form compact texture, and uses thermoplastic and the thermosetting resin that is fit to heat bonding.

United States Patent (USP) 5919178 discloses a kind of method of making absorbing structure, and this absorbing structure has an intermediate layer that comprises superabsorbent materials that is clipped between two absorbed layers, and wherein bottom can be a flimsy material.This patent disclosure when flimsy material during as upper strata or lower floor, the wet amount of flimsy material should be 20%-70% and (is 100-200kg/cm, temperature when being 120 ℃-250 ℃ at linear pressure for example, thereby just in calendering outer lining is compressed into 0.1g/cm ³Density, to make before the thick slurry mat of 1mm-4mm, be sprayed on the flimsy material with moisture).

However, this area constantly needs a kind of improved method of making absorbing material, this absorbing material satisfies be used as the needed absorbability of absorbent core, intensity and soft requirement in disposable absorbent article, also the saving that brings time and cost for the manufacturer of slurry manufacturer and absorbent article.

Summary of the invention

According to an aspect of the present invention, provide a kind of method of making absorbing material, this absorbing material does not add Chemical Felter and thermosetting adhesive.In the embodiment of a material, outer lining forms the mixture of one deck cellulose fiber peacekeeping superabsorbent materials at least.The wet amount of outer lining increases, so that increase web density.Best, this is by added about 1% the realizing to about 9% moisture of gross weight that weight is outer lining before humidification.Then, outer lining is real in the temperatures of a raising, so that further increase web density and realize hydrogen bonded in outer lining, has moisture in the outer lining hardly.After outer lining cooling, preferably keep air pressure balance so that wet amount by weight the gross weight of outer lining with moisture 2% and 8% between, be preferably between 3% to 6%.

In the method for a kind of preferred form of the present invention, by being carried, outer lining is higher than about 100 ℃ vapor area through excess temperature, thereby increase the wet amount of outer lining, this outer lining of compacting between calender roll, wherein at least one roller is heated to the interior surface temperature in zone between about 70 ℃ and about 200 ℃.

Method of the present invention can be used to make multi-form absorbing material.A kind of absorbing material of form has from about 180g/cm ²To about 600g/cm ²Basic weight, from about 0.25g/cc to the density of about 0.45g/cc.This material air lay forms a slurry (or slurry and the superabsorbent materials between slurry) bottom, starches and the middle level of the superabsorbent materials between slurry and the top layer of a slurry for one.Slurry preferably has the Kappa value less than about 100.Absorbing material comprise from about 40% cellulose fiber peacekeeping to about 90% percentage by weight have superabsorbent materials outer lining gross weight from about 10% superabsorbent materials to about 60% percentage by weight.This absorbing material have band water material gross weight less than the water content of about 10% weight percent with greater than the density of about 0.25g/cc.

For various forms of materials, preferably has relative crystallinity to the small part cellulose fibre less than about 65%.

In another form, absorbing material has from about 100g/cm ²To about 500g/cm ²Basic weight and from about 0.25g/cc to the density of about 0.50g/cc.This material comprises the core of the cellulose fibre that is obtained by slurry, wherein has Kappa value less than about 100 to the small part pulp fibres.Bearing bed (for example flimsy material layer) can be superimposed upon on the outer surface of core.Bearing bed is the crape flimsy material preferably.Has relative crystallinity to the small part cellulose fibre less than about 65%.Core comprises from about 40% to the cellulose fibre of about 100% percentage by weight with from about 0 superabsorbent materials to about 60% percentage by weight.Best, core comprises from about 40% to the cellulose fibre of about 90% percentage by weight with from about 10% superabsorbent materials to about 60% percentage by weight.

In another form, absorbing material has from about 0.25g/cc to the density of about 0.50g/cc with from about 200g/cm ²To about 500g/cm ²Basic weight.This material is made of following basically: (1) is from about 60% cellulose fibre to about 90% percentage by weight, wherein have Kappa value to the small part cellulose fibre, and have relative crystallinity to the small part cellulose fibre less than about 60% less than about 100; (2) from about 10 superabsorbent materials to about 40% percentage by weight; (3) comprise from about 3% a flimsy material layer to the absorbing material of about 20% percentage by weight.This flimsy material is the crape flimsy material preferably.

Best, material use has best cellulose fibre less than about 60% relative crystallinity and makes.Particularly, cellulose fibre has the relative crystallinity less than about 50%, even less than about 40% relative crystallinity.Obtain by the slurry that has less than about 75,50,25 or 10 Kappa value to the small part cellulose fibre.More particularly, the Kappa value is less than 5 or 2.5.

In a kind of absorbing material of form, in the material to the small part cellulose fibre by a kind of method manufacturing that comprises the steps, promptly from about 15 ℃ to about 60 ℃ temperature, the liquid suspension that water becomes aqueous solution of alkali metal salt to handle slurry reaches about 5 minutes to about 60 minutes a period of time, this water become aqueous solution of alkali metal salt have described solution from about 2% alkali metal salt concentration to about 25% percentage by weight.

In the absorbing material of another kind of form, to small part cellulose fibre flash drying.

In the absorbing material of another kind of form, cellulose fibre does not have flash drying, but handles through beater grinder.

The absorbing material of a kind of special preferred form made according to the method for the present invention has the density from about 0.28g/cc to about 0.40g/cc, and has from about 180g/cm ²To about 550g/cm ²Basic weight.

According to another aspect of the present invention, a kind of improved method of manufacturing absorbing material comprises the steps:

(A) form the outer lining with a flimsy material layer, on this flimsy material layer at least one absorbed layer is set, this absorbed layer comprises the cellulose fibre that does not add Chemical Felter and thermoset adhesive;

(B) on outer lining, spray water, so as to add weight be before the humidification outer lining weight about 2% and about 9% between the moisture of (being preferably between about 1% and about 8%); With

(C) afterwards, at the real outer lining of the temperatures of a raising,, and preferably can also realize increasing the intensity of one or more absorbed layers, and/or increase the bonding strength of flimsy material and at least one absorbed layer so that further increase web density in step (B).

Absorbing material by improved method manufacturing is characterised in that, its (I) made by the method that comprises the following steps, promptly (A) forms the outer lining with a flimsy material layer, on this flimsy material layer at least one absorbed layer is set, this absorbed layer comprises the cellulose fibre that does not add Chemical Felter and thermoset adhesive; (B) on described flimsy material layer, spray water, so as to be added on weight before the humidification be outer lining weight about 2% and about 9% between the moisture of (being preferably between about 1% and about 8%); (C) afterwards, at the real described outer lining of the temperatures of a raising,, and realize increasing the bonding of described flimsy material and described at least one absorbed layer so that further increase web density in step (B); (II) it has the bonding strength between described flimsy material layer and absorbed layer, and this bonding strength surpasses 3 newton's test stratification forces (definite according to the test that below will describe).

The second flimsy material layer also can be adhered on the side of the outer lining relative with the ground floor of flimsy material.

The feature of the absorbing material of a kind of preferred form like this can be a kind of outer lining with bearing bed, at least one absorbed layer is set on this bearing bed, this absorbed layer comprises the cellulose fibre that does not add Chemical Felter and thermoset adhesive at least, and wherein outer lining has following preferred performance:

(1) density between about 0.25 gram/cubic centimetre and about 0.5 gram/cubic centimetre;

(2) about 150 the gram/square metre and about 600 the gram/square metre between basic weight;

(3) less than about 1500 milligrams Gurley rigidity;

(4) greater than about 9 newton's machine direction tensile strength; With

(5) between described at least one absorbed layer and described bearing bed, test the bonding strength of stratification forces greater than 3 newton.

The material of preferred form has splendid absorbent properties.Absorbing material made according to the method for the present invention can be used to make absorbent article, for example diaper, feminine hygiene or incontinence device.

Description of drawings

In the accompanying drawing that constitutes a specification part:

Fig. 1 is the simplification fragmentary, perspective view by a slice absorbing material of method manufacturing of the present invention;

Fig. 2 is usually along the partial cross-sectional view of the special amplification of the plane 2-2 intercepting of Fig. 1, and in Fig. 2, the height of the part of schematic structure or thickness are exaggerative so that diagram should be appreciated that Fig. 2 needn't draw in proportion at the thickness of different piece;

Fig. 3 is the schematic diagram of the method for a kind of form of the present invention;

Fig. 4 is the view of similar Fig. 2, but Fig. 4 represents the absorbing material of another kind of form;

Fig. 5 is the view of similar Fig. 4, but Fig. 5 represents the absorbing material of another form;

Fig. 6 is the view of similar Fig. 2, but Fig. 6 represents the absorbing material of another form;

Fig. 7 is the view of similar Fig. 3, but Fig. 7 represents to be used for to make the method for the present invention of another form of absorbing material shown in Figure 6, and this absorbing material has the bonding strength of the increase between the remainder of flimsy material layer and absorbent core part;

Fig. 8 is the preceding perspective partial view of the simplification of tension force/compression test;

Fig. 9 is the perspective partial view of the top board that uses in the testing machine shown in Fig. 8;

Figure 10 is the perspective view of a part of the absorbing material of a kind of form of the present invention, and it is connected with the two-sided tape of certain-length;

Figure 11 is the perspective view that the part signal of the absorbing material part of Figure 10 is simplified, and this absorbing material partly illustrates and is arranged in hydraulic press, utilizes circle die cut round specimen;

Figure 12 is the perspective view of the cross cutting round specimen of absorbing material;

Figure 13 is the perspective view that was installed to the cross cutting sample on the top board before top board is installed in testing machine;

Figure 14 is the fragmentary, perspective view of lower platen that expression is fixed to the testing machine of a two-sided tape on the lower platen;

Figure 15 is used for the partial side elevation view of the testing machine in the work of initial compression sample;

Figure 16 is the partial view of similar Figure 14; But Figure 16 is illustrated in the after-stage of duration of test, and wherein testing machine applies tension force and sample is torn on sample; With

Figure 17 is the typical figure or the chart of load and elongation in process of the test.

The specific embodiment

Method of the present invention provides a kind of improved absorbing material, and this absorbing material is especially suitable for use as for example core in diaper, feminine hygiene, incontinence device and the analog of absorbent article.Absorbing material also can be used as the absorbent core that is used in any device of absorbing bodily effluent (for example urine, milk, blood, serum).Like this, absorbing material can be used for nursing mother's chest pad or as the absorbing material in surgical drage (for example towel) or the bandage.

The absorbing material of preferred form comprises in the fiber that is arranged on slurry and the admixture or the mixture of the cellulose fiber peacekeeping superabsorbent thing between the fiber.That absorbing material has is submissive, the combination of the uniqueness of intensity and absorbent properties, and this is particularly suitable in the absorbent article it.Absorbing material can directly use by the manufacturer of absorbent article, and does not need any additional processing of manufacturer, to replace the absorbing material cutting or to be folded into the required size and dimension of absorbent article.

Method of the present invention can be used to make softness, thin and absorbing material with higher density.In addition, this material has the absorbent properties that improved, and with superabsorbent materials securely clamping in network of fibers, and do not need to use chemicals, binding agent, bonding agent, thermoplastic resin, thermoplastic binder fiber, synthetic moulding material or analog.Absorbing material has enough globalities (intensity), so that handle in traditional disposable products manufacturing equipment, simultaneously fiber is ruptured significantly.

According to an aspect of the present invention, method of the present invention can provide a kind of absorbing material, it comprise absorbing material gross weight from about 40% cellulose fibre to about 100% percentage by weight, with the gross weight of absorbing material from about 0% about 10% percentage by weight or water still less to the gross weight of the superabsorbent materials of about 60% percentage by weight and absorbing material.

With reference to comprising a kind of composition of current material of material, the weight that phrase used herein " percentage by weight " refers to material is divided by the total binding weight of material and material (determining according to environmental condition) and multiply by 100.For instance, the absorbing material that comprises the superabsorbent materials of 10% percentage by weight refers to have 10 gram superabsorbent materials in comprising 100 gram samples of absorbing material and superabsorbent materials.

On the other hand, when relating to when current material adds the moisture of constant weight percentage or water, the percentage by weight of the water of Tian Jiaing is based on the weight of adding water material before so.

The cellulose fibre that can be used in the method for the present invention is known in the art, and comprises wood pulp, cotton, flax, peat moss.Wood pulp is best.Slurry can obtain from machinery or chemical machinery, sulphite, brown paper, slurrying obsolete material, organic solvent slurry etc.Cork and hardwood sample are useful.Soft wood pulp is best.Needn't handle cellulose fibre with chemical Degumming agent, crosslinking agent and analog in order to be used for absorbing material.

As mentioned above, the preferred cellulose fibre that is used for material of the present invention is a wood pulp.Preferably utilize the method for the content of lignin that reduces wood to prepare wood pulp.Best, the content of lignin of slurry is less than about 16%.More particularly, content of lignin is less than about 10%.Even content of lignin is less than about 5%.Best, content of lignin is less than about 1%.As known in the art, content of lignin is calculated by the Kappa value of slurry.The Kappa value utilizes the known test procedure (TAPPI tests 265-cm 85) of standard to determine.Measure the Kappa value of various slurries, and utilize TAPPI test 265-cm 85 to calculate content of lignin.Find that peat moss has about 104 Kappa value and about 13.5% content of lignin.Find that the CTMP slurry has about 123 Kappa value and about 16% content of lignin.Utilization or brown paper or sulphite process have about 1.1 Kappa value and about 0.15% content of lignin by the slurry of cork manufacturing.When the latter's slurry utilizes cold alkali extraction to handle, find that the Kappa value is about 0.97, content of lignin is about 0.12%.

In order to use in the method for the invention, cellulose fibre is preferably by the wood pulp acquisition that has less than about 100 Kappa value.More preferably, the Kappa value is less than about 75,50,25 or 10.Best, the Kappa value is less than about 2.5.

There are some further features in wood pulp, and this makes it be particularly suitable for absorbing material.Cellulose in most of wood pulps has high relative crystallinity (greater than about 65%).In a kind of material of the present invention, preferably use the wood pulp have less than about 65% relative crystallinity.Be more preferably, relative crystallinity is less than about 50%.Best is that relative crystallinity is less than about 40%.And the slurry with fiber crimp value of increase is best.

Being used to handle slurry is known so that optimize the device of these characteristics in the art.For instance, handling wood pulp with liquid ammonia knownly can reduce relative crystallinity and increase the fiber crimp value.Flash drying knownly can increase the fiber crimp value of slurry and reduce degree of crystallinity.The cold alkali treatment of slurry also increases fiber crimp and reduces relative crystallinity.Chemical crosslinking knownly can reduce relative crystallinity.Preferably be used for utilizing cold alkali treatment or flash drying to obtain by cellulose fibre to the small part of method manufacturing absorbing material of the present invention.

Find the description of cold alkali extraction in No. 08/370571 U.S. Patent application of owning together of application on January 18 nineteen ninety-five, this application is the part continuation application of No. 08/184377 U.S. Patent application that application is also abandoned now on January 21st, 1994.Disclosure in these two U.S. Patent applications provides as a reference at this.

In brief, cold alkali treatment is typically less than about 60 ℃ temperature, but is preferably less than about 50 ℃ temperature, preferably implements under the temperature between about 10 ℃ to about 40 ℃.Preferred alkali metal salt soln is the sodium hydroxide solution of new system, perhaps as the solution byproduct that produces in pulp mill or the paper mill operation, for example, the white liquid of half alkali, oxidized white liquor and analog.Also can utilize otheralkali metal for example ammonium hydroxide and potassium hydroxide etc.Yet from the viewpoint of cost, preferred salt is NaOH.The concentration of alkali metal salt be typically solution about 2% to about 25% percentage by weight, preferably from about 6% to about 18%.The slurry of two-forty fast Absorption purposes preferably utilizes from the about 10% alkali metal salt soln processing to about 18% percentage by weight.

Be as known in the art, flash drying is a kind of method of dry slurry, wherein starches partial dehydration, fibration and sends in the steam of hot-air the moisture content rapid drawdown in this causes starching to.In brief, the slurry that is initially 30-45% denseness (comprising 55-70% water) is delivered directly to (for example disk refiner) in the mixer, and the mechanical activity here is used for fibration (decompose and separate) and fiber is dispersed in the flash drying system.In case discharge from the mixer device, Fibrotic slurry is sent in the flash drying system.Drying system itself was made of two stages, and each stage is made of two drying towers.Fiber is carried through drying tower by high velocity, hot air.The intake air temperature of phase I is near 240-260 ℃, and the intake air temperature of second stage is near 100-120 ℃.Be accompanied by each drying stage, slurry and hot-air deliver into cyclone separator, and at this, the hot-air that comprises the moisture that evaporates from slurry is now vertically discharged.

In a kind of typical minisystem, in this case, the delivery temperature of phase I is about 100-120 ℃, and the delivery temperature of second stage is about 90-100 ℃.Simultaneously, the material processed fan aspirates the next part that pulp fibres passes through the cyclone cone and arrives system.At last, after the second stage cyclone separator, dry slurry passes the cooling stage that is made of the cooling fan of carrying surrounding air, passes final cooling cyclone separator then.The time of staying that comprises the total system of drying stage, cyclonic separation and cooling is about 30-60 second under the feed speed of using (1.5kg dry substance/minute, this is the feed speed of typical small-sized machine).Fairly large traditional flash drying system typically has higher feed speed.

The final stage of utilizing the system of the above-mentioned type to make the fiber of flash drying is to make local fibre bundle in final products.During pulp fibresization, form fibre bundle by the mechanism in the mixer device.The said system cause disk refiner of forming by the plectane of two flutings that are maintained fixed gap width, in this case, this fixed interval (FI) width is 4mm.A plate is to be in a fixed position, and another piece plate is with rotation at a high speed.The slurry feed enters in the gap between the two boards, and the rotation of plate causes fiber to separate along groove.Unfortunately, when pulp fibres, what the independent fiber of part tended to become tangles mutually, forms the tuftlet by plurality of single fiber groove.When these fiber flash dryings of tangling and when discharging moisture, tangle tensioning and sclerosis so that in whole flash drying slurry, form little local fibre bundle.The a large amount of local fibre bundle that exists in the final air lay product that utilizes the flash drying slurry to make has harmful effect to the physical features and the performance of product.By utilizing cold alkali extraction slurry, the quantity of local fibre bundle reduces basically.

A kind of absorbing material that comprises superabsorbent materials is made in an aspect (as described later) of the method according to this invention.In the art, superabsorbent materials is known.As used herein, term " superabsorbent materials " refers to can absorb with respect to its weight the water-fast basically polymeric material of a large amount of fluids.Superabsorbent materials can be into particulate matter, thin slice, fiber and analog.The exemplary particles form comprises particle, ball, pellet and the agglomerate of particulate, pulverizing.Superabsorbent materials can be from buying (for example from StockhausenGmbH, Krefeld, Germany) often.A kind of preferred form of absorbing material comprises from about 0 superabsorbent materials to about 60% percentage by weight, particularly from about 20% to about 60% superabsorbent materials.The absorbing material of this preferred form has from about 40% to the cellulose fibre of about 100% percentage by weight and best from about 40% to about 80% cellulose fibre.

According to a further aspect of the invention, the outer lining that provides unique method to be used for making absorbing material, but this method can not adopt superabsorbent materials in the each several part of whole outer linings even outer lining.

The form of absorbing material

Absorbing material by method manufacturing of the present invention preferably have the gross weight that accounts for absorbing material less than about 10% wet amount, to hinder bacterial growth.And material does not add Chemical Felter and thermoset adhesive.

Fig. 1 represents a kind of absorbing material of form, and it can be by method manufacturing of the present invention.Absorbing material is represented by Reference numeral 20 in Fig. 1 usually.For the manufacturer of absorbent article, material 20 is made the sheet of a broad usually by method of the present invention, and this sheet can be the form of sheet or the form of big volume.The typical thickness of material is between 0.5mm to 2.5mm.

Fig. 2 represents the cross section of material.The different-thickness zone of the material 20 that Fig. 2 represents is expression in proportion not necessarily, and in some cases, it can amplify so that clear and convenient diagram.

Absorbing material 20 shown in Figure 2 comprises an optional bearing bed 22.Bearing bed 22 can for example be by spunbond, melt-blown non-woven thing natural or that synthetic fiber constitute.The another kind of preferable material that can be used for bearing bed is a flimsy material.

To those skilled in the art, be known as the suitable sheer fabric material that absorbs the bearing bed in the product.Best this flimsy material is made by the wood pulp of bleaching, and has the gas permeability of about 273-300CFM (cubic feet per minute).The tensile strength of flimsy material makes it keep globality during the shaping of absorbing material and calendering.Suitable MD (machine direction) and CD (cross-directional) tensile strength represented with Newton/meter are about 100-130 and 40-60 respectively.The flimsy material that is used for the air lay absorbing material be commercially available (for example by Cellu Tissue company, 2 Forbes Street, East Hartford, CT 06108, the U.S. and by Duni AB, Sweden).In a preferred embodiment, flimsy material is the crape fabric that per inch has the crape of quantity sufficient, with the percentage elongation (this is determined by SCAN P44:81 test method) between 20% and 35% that allows machine direction.

Absorbing material 20 on the flimsy material layer 22 generally includes one or more different layers.The quantity of every layer thickness and layer can change.Fig. 2 represents to be applied to especially the material of the business form of the present application in the feminine hygiene.Absorbing material 20 shown in Figure 2 comprises the bottom or ground floor 24,26, the three layers 28 and the 4th layers of the second layers or top layer 30.In a kind of form of absorbing material shown in Figure 2 20, layer 24,26 and 28 limits absorbent core part 36 together.Optionally top layer 30 is characterised in that usually it is below with transition zone, securing layer or the transport layer described in detail.

Layer 24,26,28 and 30 is preferably multilayer, initially is laid to independent layer or one deck in the method for the invention and is positioned at layer on another layer because form the material of these layers, and this will be discussed in more detail below.Yet after the method for making absorbing material finished, each layer became single or integrally-built part.Typically, between different layers, there is recognizable hardly vision difference.If someone attempts absorbing material is separated in manufacture method initial each layer of laying, he the absorbing material of finding to finish is difficult to separately or layering and formation corresponding to each layer that particularly can distinguish of each layer of in manufacture process, laying.

Best, when bearing bed when for example flimsy material layer 22 uses, flimsy material layer 22 is embedded in the bottom 24 of absorbent core part 36 a little, and in process, this is by below with knurling roller or the realization of flax roller (or other cotton ginning) calender roll described in detail.Best, if use annular knurl or flax calender roll, the annular knurl of roller or flax surface have 5% the degree of depth greater than the thickness of bearing bed (flimsy material layer).

Typically, absorbent article manufacturer adds surface layer, top flat or rubber cover (not shown), the people's of this surface layer and wearing article contact skin on transition zone 30.Top transition zone 30 passes the liquid (for example menstruation or urine) of surface layer as securing layer with the phase I that is contained in drainage.This transition zone 30 is gathered the liquid from the surface layer of absorbent article rapidly, and this liquid is dispensed to absorbent core 36.Transition zone 30 keeps a segment distance between surface layer and core 36, so that stop liquid from the backflow wearer's skin of absorbent article of core 36.Transition zone 30 is convenient to the liquid deflection dispersion, particularly at liquid second be discharged into stage in the absorbent article subsequently.In an alternative embodiment, transition zone 30 can omit.

Layer 24,26 and 28 comprises pulp fibres 32, and this pulp fibres has the typical average length of about 2.40mm.Best, make by above-mentioned cold alkali extraction to small part pulp fibres 32.This be included in from about 15 ℃ to about 60 ℃ temperature, water becomes the liquid suspension of the slurry of aqueous solution of alkali metal salt pack processing cellulose fiber to reach about 5 minutes to about 60 minutes a period of time, this water become aqueous solution of alkali metal salt have described solution from about 2% alkali metal salt concentration to about 25% percentage by weight.Then, the pulp cellulose fiber of handling or through flash drying or pass beater grinder and handle.

Each preferably includes the superabsorbent materials of aforementioned type the layer 24,26 and 28 of absorbent core part, and preferably is arranged to the form of superabsorbent particle or particulate 40.Top transition zone 30 does not contain the superabsorbent particulate.If omit transition zone 30, the top layer (for example absorbent core part top layer 28) in each layer of all the other absorbent core parts does not preferably contain the superabsorbent particulate so.

In a kind of preferred form of the absorbing material with transition zone 30 20 shown in Figure 2, each layer 24,26 and 28 of each absorbent core part 36 comprises the superabsorbent particulate.If desired, each layer that comprises slurry and superabsorbent thing can be laid to homogenous mixts or heterogeneous body mixture, and wherein superabsorbent thing content is from (being end bearing bed 22) changes to the bottom nearby.In the absorbing material of improved form, the concentration of the superabsorbent materials in every layer 24,26 and 28 (percentage by weight) can change, and the character of specific superabsorbent materials or type also are like this.And superabsorbent materials can be limited in the only one deck or part layer that constitutes absorbent core hole part 36.

Best, total basic weight of slurry in bottom 24 and superabsorbent materials is typically about 50 and about 270g/m ²Between.Layer total basic weight of 26 is typically about 50 and about 270g/m ²Between.Layer total basic weight of 28 is typically about 20 and about 270g/m ²Between.Total basic weight of top layer 30 is typically about 0 and about 50g/m ²Between.

The preferred thickness of top transition zone 30 is in the scope of about 0.20mm and about 0.50mm.Each sandwich layer 24,26 and 28 preferred thickness are in the scope of about 0.2mm and about 0.9mm.In some cases, the thickness of each sandwich layer can be low to moderate 0.04mm or littler.

The preferable range of the averag density of absorbing material 20 is 0.25 and 0.5g/cm ³Between.With the ambient air balance after, the wet amount of absorbing material 20 is best less than about 10% (accounting for the percentage by weight of total material weight), is more preferably less than about 8%, preferably drops between about 3% and about 8%.

Manufacture method and equipment: first embodiment

Above-mentioned absorbing material can be by method manufacturing of the present invention.First embodiment of method of the present invention is schematically illustrated by Fig. 3.Illustrated method has adopted the ring-type silk, sieved or has been with 60, and the absorbing material parts deposit thereon.

This method allows bearing bed selectively to be applied in this absorbing material (for example, the flimsy material layer 22 in the above-mentioned absorbing material 20 shown in Figure 2).For this purpose, flimsy material outer lining 62 is by 64 debatchings of flimsy material clad can material roller, and guiding is on ring-type sieve 60.A series of forming heads 65 are arranged on the ring-type sieve 60.In the preferred form of this method, this series comprises first forming head 71, second forming head 72, the 3rd forming head 73 and the 4th forming head 74.Can provide the more or less forming head of quantity according to having laid how many layer materials.

Cellulose fibre utilizes traditional beater grinder (not shown) to handle, so that fiber is handled respectively, this cellulose fibre of part becomes the form of the pulp fibres of above-mentioned cold alkali extraction.The fiber of Chu Liing mixes with superabsorbent materials, particle or particulate in the independent hybrid system of each forming head is provided respectively.Forming head 71 is connected with hybrid system 81, and forming head 72 is connected with hybrid system 82, and forming head 73 is connected with hybrid system 83.In the part system, pulp fibres and superabsorbent particle or particulate pneumatically are sent to forming head, and are mixed together in forming head.In other systems, pulp fibres and superabsorbent particle or particulate are sent to forming head separately, and are mixed together in forming head.Between fiber treatment or fiber and superabsorbent materials mixing period, do not add Chemical Felter and thermoset adhesive.

Forming head 74 is connected with hybrid system 84, and forming head 74 provides pulp fibres or other parts for top transition zone 30.Top layer 30 does not have the foregoing superabsorbent materials with reference to absorbing material 20 shown in Figure 2.

The mixing of material and distribution can be controlled separately at each forming head.For example, in some systems, controlled atmosphere circulation and band wing agitator produce and mix and distribute (

hybrid system

81,82 and 83 slurry and the only pulp fibres of superabsorbent particulate and hybrid system 84) basically uniformly in each hybrid system.

The superabsorbent particulate can or in the mixing fully and with quality everywhere of the absorbent core part of the structure of manufacturing, thereby perhaps only be included in a certain layer or the multilayer by the superabsorbent particulate being assigned to selected forming head.

If desired, the superabsorbent particulate can divide each layer that is equipped with as 100% superabsorbent thing separately from independent forming

head

91,92 and 93.In this selectable structure, superabsorbent particulate forming head 91 is positioned between forming

head

71 and 72, and superabsorbent particulate forming head 92 is positioned between forming

head

72 and 73, and superabsorbent particulate forming head 93 is positioned between forming head 73 and 74.If adopt independent superabsorbent

particulate forming head

91,92,93, so Fu Jia superabsorbent particulate also can mix in

hybrid system

81,82 and 83.As an alternative, have only pulp fibres to carry respectively and through

hybrid system

81,82 and 83 and forming

head

71,72 and 73, this moment, superabsorbent materials was discharged from forming

head

91,92 and 93.

From the material vacuum moulding machine of each forming head (or directly being deposited on the ring-type sieve 60) on flimsy material outer lining or the bearing bed 62, to form the absorption outer lining of layering.The absorption outer lining of layering end from circulation sieve 60 under the help of traditional vacuum transmitting device 100 is transported to moisture interpolation equipment 110.As an alternative, system can be designed to cancel transmitting device 100.

Equipment 110 typically comprises a shell or capsule and proper device, and this proper device is used to provide moisture and/or the control moisture in the capsule of the outer lining of layering.In the embodiment of an application, moisture can with the form of low-pressure steam on the top and bottom side of the outer lining of layering nozzle or only from the bottom side feed.In the embodiment of Another application, moisture passes nozzle 114 feeds on the outer lining with the form of low-pressure steam.On the side of the outer lining relative with nozzle 114, equipment can comprise a steam suction chamber 118.Other device can be arranged in the device 110, and to form around the required atmosphere of the outer lining of layering, wherein the wet amount of atmosphere is controlled.

In one of the method for the present invention preferred embodiment of using at present, moisture is with about 0psi steam form feedway 110 of the temperature between the pressure between about 20psi and about 100 ℃ and about 125 ℃ extremely.Steam is preferably to remain on a side of outer lining at least about 100 ℃ temperature.The outer lining of steam inflow and process layering, thereby the wet amount of increase outer lining.The preferred form of first embodiment of the method according to this invention, just after accepting the steam effect, the wet amount of outer lining is about 10% less than the gross weight of outer lining, preferably less than about 9%.There is not the heat bonding of pulp fibres.Yet at present still believing to moisturize has increased the density of outer lining, and is convenient to the formation of the mutual hydrogen bonded of pulp fibres, and the combining of flimsy material layer and pulp fibres, and this has increased the intensity or the globality of the absorbing material of finishing.

When the outer lining of the layering that moisturizes left moisture adding set 110, it was to be compressed or to compress between top roll 121 and the lower roll 122 at a pair of heating calender roll.This has increased the density of outer lining.Do not contain in the preferred form of superabsorbent materials at top layer, the superabsorbent materials in the bottom of outer lining does not contact and clings calender roll in the heating.

Top roll 121 is typically steel rider, and lower roll 122 is typically the bending roll with about 85SH D hardness.Although these two kinds of rollers are smooth, in a preferred method, top roll 121 has smooth surface, and lower roll 122 has knurled surface.The effect of knurled surface is the bottom of the bearing bed of flimsy material layer 62 or other type being imbedded absorbing material.Best, knurled surface has 5% the degree of depth greater than bearing bed thickness.

Each

roller

121 and 122 is heated to the temperature between about 70 ℃ and about 200 ℃, preferably is about 150 ℃.The weight bearing of top roll 121 is on the outer lining of layering.Act on roller 121 the axle on traditional hydraulic unit driver (not shown) can apply additional force.In a kind of form of the present invention, about 28 and the horizontal outer lining width of about 400 Newton/millimeter (160-2284 ft lbf/inch laterally outer lining width) between the load effect under, outer lining compacting between roller 121 and 122.Believe at present to add the density that hot compaction has increased outer lining, and influence the formation of the mutual hydrogen bonded of pulp fibres, and combining between flimsy material layer and the pulp fibres, so that increase the intensity and the globality of the absorbing material of finishing.This provides unusual resistance for final product, to remove superabsorbent materials.Owing to leave calender roll, outer lining comprises moisture seldom.

Compression and closely knit outer lining utilize traditional Wiring apparatus to be wound on the roller 130.The wet amount of outer lining typically increases, because outer lining reaches the balance with ambient atmosphere, but preferably wet amount is too not high, be preferably in outer lining gross weight about 3% to about 8% between.

Processing line is preferably with the linear velocity operation of about 0.5 meter per second to about 5.0 meter per seconds.The duration of outer lining in moisture adding set 110 is preferably between about 0.1 to about 1.0 seconds.

The preferred form of the current application of first embodiment of method of the present invention has adopted

calender roll

121 and 122, so that apply heat and pressure to outer lining.Yet, be appreciated that the present invention also adopts other device, so that compacting outer lining and heat to outer lining.For example, can adopt a pair of mobile heated platen to replace calender roll.As an alternative, can adopt relative heating endless belt assembly to replace calender roll to come compacting and heating outer lining.At last, the device of extruding and compacting outer lining can separate with the device to the outer lining heating.Yet seeming the most practical at present is with these devices as the combination of heating calender roll.

The feature of absorbing material

The single or multiple lift absorbing material of the first embodiment manufacturing by method of the present invention has high relatively density and has composite denseness more preferably greater than about 0.25g/cc.In a preferred embodiment, absorbing material has from about 0.25g/cc to the composite denseness between about 0.50g/cc.Be more preferably, this density be from about 0.25g/cc between about 0.45g/cc.Best, this density be from about 0.28g/cc between about 0.40g/cc.

The high density absorbing material that comprises superabsorbent materials by method manufacturing of the present invention astoundingly and unexpectedly submissive.Term used herein " submissive " is used for describing the feature of softness, elasticity and flexible.Features relevant is a Gurley rigidity, and it measures the rigidity of absorbing material.The Gurley rigidity value is big more, and material has rigidity and elasticity more.Like this, the inverse (g to restrain ^-1) inverse of Gurley rigidity of expression is softness, flexible and flexible the measuring of absorbing material.Submissively be defined and show as the reciprocal of Gurley rigidity and have the g of unit ^-1

Although the high density absorbing material is submissive sufficient intensity is arranged.The pad globality is the well-known features of absorbing material intensity.High density absorbing material by method manufacturing of the present invention has good intensity (high pad globality).

Absorbing material can be prepared into by method of the present invention has basic weight widely, and can not influence its softness or intensity conversely.Like this, absorbing material can have from about 50g/m ²To about 800g/m ²Or basic weight in larger scope.In a kind of preferred form, basis weight range is from about 100g/m ²To about 500g/m ²In the scope, be more preferably from about 100g/m ²To about 250g/m ²Or from about 300g/m ²To about 500g/m ²In the scope.

Method of the present invention can be used to make when comparing the absorbing material with outstanding absorbent properties with existing material.The absorbent properties of material can be evaluated in many ways.Material opposing load that relevant especially with the manufacturer of absorbent article is absorbs a large amount of fluids and fluid is distributed the ability of leaving fluid deposition point or inlet point.

Wicking is that absorbing material guiding fluid leaves the fluid inlet point and fluid distributed the ability that runs through material.Absorbing material by method manufacturing of the present invention has the good wicking performance.

The combination of the intensity of the absorbing material by method manufacturing of the present invention, absorbability and submissive uniqueness has significant advantage for the manufacturer of absorbent article.Typically, this manufacturer buys slurry, then when manufacturing end article (for example diaper, sanitary napkin) at this slurry of manufacturing works' online treatment.This treatment step can comprise the step of the fiber separation that makes slurry, adds superabsorbent thing and analog.In on-line system, the rapid degree that these steps are implemented is limited by step the slowest in the different step.An example (for example fiber separation) of the slurry of this treatment step of needs is open in United States Patent (USP) 5262005.

The online needs that existing material fiber separated or handle of manufacturer mean that total manufacture method is more complicated in fact.And manufacturer must buy, keeps and operate required equipment, to implement this treatment step.Like this, total cost of production increases.

Such absorbing material by method manufacturing of the present invention can directly apply in the required absorbent article, and does not need this treatment step.The manufacturer of absorbent article has to make fiber separation or handles the absorbing material that method of the present invention is made, this method with any be not that absorbing material is configured as required form is that mode is implemented.By this way, manufacturer can quicken installation process, and realizes cost and the substantial saving of time.

Method of the present invention can be used to make the absorbing material with superperformance, so that keep superabsorbent materials when bearing mechanical stress.

The form that is used for the absorbing material that uses in feminine hygiene

Fig. 4 represents three layers of form of the absorbing material 300 that first embodiment of the method according to this invention makes, and this material is specially adapted to feminine hygiene.This absorbing material has from about 100g/m ²To about 250g/m ²Basic weight in the scope and the density between about 0.25g/cc and the 0.5g/cc.Particularly, density from about 0.28g/cc to about 0.45g/cc, preferably, density is from about 0.28g/cc about 0.33g/cc extremely.

In a kind of variation example, absorbing material 300 air lays that are used for feminine hygiene are three layers: comprise basic weight and be about 25g/m ²The bottom 301 of slurry (no superabsorbent thing); Basic weight is about 150g/m ²And comprise from about 10g/m ²To about 30g/m ²Superabsorbent thing 40C and from about 120g/m ²To about 140g/m ²The middle level 302 of slurry; With comprise basic weight and be about 25g/m ²The top layer 303 of slurry (no superabsorbent thing).With respect to the gross weight of absorbing material 300, the content range of superabsorbent thing 40C from about 5% to about 40% percentage by weight (every g/m ²The g/m of the superabsorbent thing of material ²).Best, the contents level of superabsorbent thing be absorbing material 300 from about 7.5% to about 12.5% percentage by weight.More particularly, absorbing material 300 comprises the superabsorbent thing that is about 30% percentage by weight.Like this, the middle level 302 of absorbing material 300 preferably comprises from about 15% to about 25% superabsorbent thing and from about 125g/m ²To about 135g/m ²Slurry, be more preferably about 20g/m ²Superabsorbent thing and about 130g/m ²Slurry.The middle level 302 that comprises slurry and superabsorbent thing can be laid to homogenous mixts, or the heterogeneous body mixture, and wherein the level of superabsorbent thing changes to bottom from nearest layer.If desired, the superabsorbent thing also can add bottom.

Fig. 5 represents the another kind of form of absorbing material 400, and this material becomes four layers by method air lay of the present invention: layer 401, layer 402, layer 403 and layer 404.The feature of

layer

402 and 403 can be two intermediate layers: near first middle level 403 of top layer 404 and second middle level 402 of close bottom 401.Each of first and second middle levels comprises independently from about 10g/m ²To about 30g/m ²Superabsorbent thing 40D and from about 40g/m ²To about 65g/m ²Slurry.When the fluid that absorbs when hope leaves the top (promptly leaving the surface near wearer's goods) of feminine hygiene, the amount of the superabsorbent thing in first and second

middle levels

403 and 402 is through overregulating, so that there is the superabsorbent thing of high level level in second middle level.Superabsorbent thing in first and second middle levels 403 in 403 can be identical or different superabsorbent thing.Bottom 401 and top layer 404 do not contain any superabsorbent materials.Yet if desired, the superabsorbent thing can add bottom to.

The form that is used for the absorbing material of diaper and incontinence product

In another kind changed example, the absorbing material of the first embodiment manufacturing by method of the present invention was specially adapted to diaper and incontinence product.Because this goods absorb than the feminine hygiene products expectation and keep more sticking hardly fluid, this goods adopt heavier, like this, have from about 300g/m ²To about 500g/m ²The absorbing material of the preferred basis weights in the scope.Total composite denseness of material is between about 0.3g/cc and 0.5g/cc.More particularly, total composite denseness is from about 0.35g/cc to about 0.45g/cc, preferably is about 0.38g/cc.

In a kind of mode of similar above-mentioned feminine hygiene, but be applicable to that the material air lay of diaper is one or more layers, for example two-layer, four layers or multilayer.When using three layers (Fig. 4), bottom 301 has about 50g/m ²Basic weight.Middle level 302 has the 300g/m of being about ²Basic weight, and comprise from about 40g/m ²To about 200g/m ²Superabsorbent thing 40C and from about 100g/m ²To about 260g/m ²Slurry; Top layer 303 has the 50g/m of being about ²Basic weight.Best, the middle level comprises from about 70g/m ²To about 170g/m ²Superabsorbent thing and from about 130g/m ²To about 230g/m ²Slurry.Even best, middle level 302 comprises about 80g/m ²Superabsorbent thing and about 220g/m ²Slurry, perhaps about 160g/m ²Superabsorbent thing and about 140g/m ²Slurry.Comprise that the slurry and the middle level of superabsorbent thing can be laid in homogenous mixts or as the heterogeneous body mixture, wherein the contents level of superabsorbent thing changes to bottom from nearest layer.If desired, the superabsorbent thing also can add bottom to.

Change example (Fig. 5) at four layers that are used for diaper and adult incontinence products, absorbing material 400 has two

middle levels

403 and 403, and they comprise independently from about 20g/m ²To about 100g/m ²Superabsorbent thing 40D and from about 50g/m ²To about 130g/m ²Slurry.In a preferred embodiment, second (descending) middle level 402 have than first (on) the middle level 403 superabsorbent thing 40D of high-load level more.By this way, the fluid of the absorbing material 400 of shaping with the absorption of making leaves the wearer's of goods the trend of body surface.Superabsorbent thing 40D in first and second middle levels 403 in 402 can be identical or different material.If desired, the superabsorbent thing can add bottom to.

Absorbing material by forwarding method manufacturing of the present invention can be applicable in absorbent article such as the single or multiple lift structure.The device that utilization is folded to form this structure is known in the art.For instance, those of ordinary skill in the art can " C folding ", " G be folding " before using it for absorbent article, or " Z-folded ".

The improved form of absorbing material

Fig. 6 represents the another kind of form of absorbing material 520, and it can be made by another embodiment of method of the present invention.Absorbing material 520 comprises flimsy material layer or bearing bed 522, ground floor 524, the second layer 526 and the 3rd layer or top layer 529.In the form of absorbing material shown in Figure 6 520, layer 524,526 and 529 has defined the absorbent core part 536 with flimsy material bearing bed or flimsy material layer 522 together.In this certain embodiments, there are not transition zone or securing layer.Yet that is available optional layer, and the 26S Proteasome Structure and Function of this layer is the same with 26S Proteasome Structure and Function with reference to the above-mentioned transition zone 30 of first embodiment shown in Figure 2.

For the above-mentioned layer of first embodiment shown in Figure 2, the layer 525,526 and 529 of embodiment shown in Figure 6 is called as layer, because the material that forms this layer initially is laid to independently layer or the layer of one deck on another layer top with the form of method of the present invention.A kind of form of making the equipment of absorbing material 520 shown in Figure 6 or processing line is as follows with reference to figure 7.

After finishing the method for making absorbing material 520, layer becomes a single or integrally-built part.Typically, between different layers, there is recognizable hardly vision difference.If someone attempts absorbing material is separated into initial each layer of laying in manufacture method, he is with each layer that the absorbing material of finding to finish is difficult to separately or layering particularly can be distinguished with formation, and this each layer that can distinguish is corresponding to each layer of laying in manufacture process.

In absorbing material 520, special wish be flimsy material layer 522 effectively and be glued fast on the absorbent core part bottom 524, and can be not on the contrary or influence the physical property of material 520 nocuously, for example fill up globality, softness, flexible, elasticity, submissive and tensile strength.

Flimsy material layer 522 can have the identical composition of flimsy material layer 22 among first embodiment with above-mentioned absorbing material 20 shown in Figure 2.For the certain embodiments of absorbing material shown in Figure 6 520, flimsy material layer 522 can be 100% a southern softwood bleached pulp of traditional type.

The layer 524,526 and 529 of absorbent core part all comprises the pulp fibres 532 with pulp fibres 32 same form of first embodiment of absorbing material shown in Figure 2 20.Absorbing material 520 preferably includes at the ground floor 524 of absorbent core part 536 and superabsorbent particulate in the second layer 526 or particle 540.Be distributed to identical mode in the layer 24 and 26 of first embodiment of above-mentioned absorbing material 20 shown in Figure 2 with a kind of and superabsorbent particulate 40, this superabsorbent particulate 540 is distributed in two-layer 524 and 526 everywhere.

In the preferred embodiment of absorbing material shown in Figure 6 520, the 3rd layer or top layer 529 do not comprise any superabsorbent particulate 540.Although the superabsorbent particulate can be arranged in the top layer 529, be preferably in many application, top layer 529 does not contain the superabsorbent particulate.The concentration (percentage by weight) of the superabsorbent materials 540 in every layer changes, and the character of specific superabsorbent materials or type also are like this.

Manufacture method and equipment: improve

As mentioned above, make absorbing material 20 shown in Figure 2 with reference to equipment that utilizes improved form and method, absorbing material 520 shown in Figure 6 can be according to the embodiment manufacturing of equipment shown in Figure 3 and method.Fig. 7 represents to make the equipment and the method for the improved form of absorbing material shown in Figure 6 520.

This method is adapted at using in the absorbing material bearing bed (for example with reference to figure 6 the flimsy material layer 522 in absorbing material 520) as mentioned above.For this purpose, flimsy material outer lining 62 is from 64 debatchings of flimsy material clad can material roller and guide on the ring-type shown in Figure 7 sieve 60.On ring-type sieve 60, provide a series of forming heads 65 with the deposit fiber cellulose fiber.In the method for preferred form, this series comprises first forming head 71, second forming head 72 and the 3rd forming head 73.More or less how many forming heads of quantity can be determined according to the number of plies of material-paving.

Cellulose fibre preferably includes from the finished slurry of brown paper of (1) the 100% finished slurry of southern loose brown paper and (2) above-mentioned cold alkali treatment (for example cold alkali extraction pulp fibres), mixture.The traditional beater grinder (not shown) of this fiber utilization is handled so that handle fiber respectively.The fiber of handling respectively is preferably in the independent hybrid system that forming

head

71 and 72 are provided and mixes with superabsorbent materials, particle or particulate.Forming head 71 is connected with hybrid system 81, and forming head 72 is connected with hybrid system 82.In the part system, pulp fibres and superabsorbent particle or particulate pneumatically are sent to forming

head

71 and 72 also to be mixed therein.Forming head 73 can have hybrid system 83, if but the top layer 529 of absorbing material 520 manufacture and do not contain the superabsorbent thing, then hybrid system 83 inoperation mix the superabsorbent particulate.In other systems, pulp fibres and superabsorbent particulate or particle transfer to forming head separately, and are mixed together in forming head.Between fiber treatment or fiber and superabsorbent materials mixing period, preferably do not add Chemical Felter and thermoset adhesive.

The mixing of material and distribution can be controlled separately at each forming head.For example, in some systems, in each hybrid system, controlled atmosphere circulation and band wing agitator produce and mix and distribute (the only pulp fibres of the pulp fibres of

hybrid system

81,82 and superabsorbent particulate and hybrid system 83) basically uniformly.

If desired, the superabsorbent particulate can divide the individual layer that is equipped with as 100% superabsorbent thing separately from independent forming head 91 and 92.In this selectable structure, superabsorbent particulate forming head 91 is positioned between forming

head

71 and 72, and superabsorbent particulate forming head 92 is positioned between forming head 72 and 73.If adopt independent superabsorbent

particulate forming head

91,92, so Fu Jia superabsorbent particulate also can mix in hybrid system 81 and 82.As an alternative, have only pulp fibres to carry respectively and through

hybrid system

81 and 82 and forming

head

71 and 72, this moment, superabsorbent materials was discharged from forming

head

91 and 92.

From the material vacuum moulding machine of each forming head on flimsy material outer lining or bearing bed 62, to form the absorption outer lining of layering.The absorption outer lining of layering can but need be under the help of traditional vacuum transmitting device 100 not be transported to moisture and add spraying equipment 150 from the end of circulation sieve 60.The steam that adopts in first embodiment of method shown in Figure 3 adds capsule 110 and cancels in second embodiment of method shown in Figure 7.As an alternative, system can be designed to can also be used for cancelling transmitting device 100.

Spraying equipment 150 comprises six spray nozzles that distribute along the width of outer lining.The quantity of nozzle can be according to the size or the wide variety of processing line.Each nozzle is oriented in against the water spray of the downside guiding cone shaped pattern of flimsy material layer outer lining 62.Each nozzle is that variable injecting sprays automatic air automatic nozzle type 1/8 VAA-SS+SUV67-SS automatically, and it is by spraying system company, North Avenue at Schmele Road, and P.O.Box 7900, Wheaton, Illinois 60189, and USA sells.Can use the nozzle of other type.

Nozzle is positioned at about 10 inches places below the flimsy material layer outer lining, and opens 30cm (be between the adjacent nozzle distance be 30cm) along the width central compartment of outer lining.Water pressure is regulated so that the liquid that is ejected into the requirement on the outer lining to be provided.In the method for present preferred form, water pressure is maintained at about 15psig, with the moisture of the interpolation that obtains 3% percentage by weight (based on the weight of adding absorbing material outer lining before the moisture).Water temperature is maintained at about 15 ℃.Water temperature can improve or reduce if desired.The type of nozzle, setting, operation and quantity can be according to the type of flimsy material, the composition and the structures of absorbent core part 536, the size of processing line, and linear velocity, the character of downstream waits and changes.

In the preferred embodiment of the present employing of method shown in Figure 7, the wet amount of outer lining increases, and is adhered to the bottom of absorbent core part to realize flimsy material layer outer lining 62 (gas producing formations of finishing 522 among Fig. 6), and can be thermally bonded on the pulp fibres.

Cross after moisture adds injection apparatus 150 at the outer lining of the layering that moisturizes, it a pair of heating calender roll be between top roll 121 and the lower roll 122 by compression or compress.This has increased the density of outer lining.Do not contain in the preferred form of superabsorbent materials at top layer, the superabsorbent materials in the bottom of outer lining does not contact and clings calender roll in the heating.

Top roll 121 is typically steel rider, and lower roll 122 is typically the bending roll with about 85 SH D hardness.Although these two kinds of rollers are smooth, in a preferred method, top roll 121 has smooth surface, and lower roll 122 is rough.Lower roll 122 can have knurled surface.Best, lower roll 122 is characterised in that it is " flax roller " with non-smooth surface, and this flax roller has the three-dimensional structure or the impression of flax shape fabric.The effect of non-smooth surface is the bearing bed of flimsy material layer outer lining 62 or other type is imbedded the bottom of absorbing material.Best, the indentation on flax roller surface has 5% the degree of depth greater than bearing bed 522 thickness.

A kind of form that is used for being manufactured on flax roller of the following described sample of the present invention of " example " part by name is, by Saveressig GmbH ﹠amp; Co.Gutenbergstrasse1-3, D-48691 Vreden, Germany sells and the design label is flax roller of 204RE87.This roller is by metal alloy 42 CrMo manufacturing and without nitrated.Roller diameter is 500mm, and roller bag (bale) width is 1950 μ m.The Gravour width is 1850mm, and the gravour degree of depth is 300 μ m.

Each

roller

121 and 122 is preferably the temperature that is heated between about 70 ℃ and about 200 ℃, preferably is about 150 ℃.The weight bearing of top roll 121 is on the outer lining of layering.Act on roller 121 the axle on traditional hydraulic unit driver (not shown) can apply additional force.In a kind of form of method of the present invention, about 160 and the horizontal outer lining width of about 2284 ft lbfs/linear inch between preferred load range under, preferably about 515 ft lbfs/linear inch, outer lining compacting between

roller

121 and 122.

Believe at present to add the density that hot compaction has increased outer lining, and (Fig. 6) forms the mutual hydrogen bonded of pulp fibres in the layer of absorbent core part 536, and combining between the interior pulp fibres of the bottom 524 of flimsy material layer 522 and absorbent core part 536.Compacting has also increased the physical entanglement of fiber.These factors have increased the bonding delamination strength between absorbent core part 536 and the flimsy material layer 522.The intensity and the globality of the absorbing material of finishing 520 have also been increased.This prevents that flimsy material layer 522 is from bottom 524 layerings of absorbent core part 536 during material is for example being made the absorption product of employing absorbing material 520 between the operating period.This also provides unusual resistance for the product of finishing, to remove superabsorbent materials.Yet, surprisingly, do not have adverse influence aspect soft, submissive and the absorbability.

A preferred range of processing line speed be about 30 and about 300 meters/minute between, favor speed is 90 meters/minute.

Compression and closely knit outer lining utilize traditional Wiring apparatus to be wound on the roller 130.

Utilize the single or multiple lift absorbing material 520 of the embodiment manufacturing of method of the present invention shown in Figure 7 to have high relatively density and have composite denseness more preferably greater than about 0.25g/cc.In a preferred embodiment, absorbing material 520 has from about 0.25g/cc to the composite denseness between about 0.50g/cc.Be more preferably, this density be from about 0.28g/cc between about 0.45g/cc.

Absorbing material can be prepared into by method of the present invention shown in Figure 7 has basic weight widely, and can not influence its softness or intensity conversely.Like this, absorbing material can have from about 50g/m ²To about 800g/m ²Or basic weight in larger scope.In a preferred form, basic weight is from about 100g/m ²To about 500g/m ²In the scope.

The embodiment of method of the present invention shown in Figure 7 can be used to make compare with existing material has the splendid absorbability and the absorbing material of wicking properties.

The form of the absorbing material of the embodiment manufacturing by method shown in Figure 7 has the flimsy material layer, and this flimsy material layer is adhered to absorbent core and partly goes up and have higher intensity.Concerning the processor or manufacturer of absorbent article, the combination of the submissive uniqueness of the bonding and total strength of materials of high-strength flimsy material, absorbability, good wicking performance and absorbing material that the embodiment by method shown in Figure 7 brings has significant advantage.When making end article (for example diaper or sanitary napkin), absorbing material can be handled and process at an easy rate, and absorbing material will bear this processing, can not remove flimsy material simultaneously, and material monolithic can not lost significantly.As a result, manufacturer can handle absorbing material and make it to have splitting of runnability and minimizing better.

The sample of absorbing material 520 shown in Figure 6 after tested, with the bulk strength of the material estimating to compare with the flimsy material layer 522 and the adhesive strength between the bottom 524 of absorbent core part 536.Some samples are by method manufacturing shown in Figure 7 usually.Except water is not to be ejected on the flimsy material layer and the calendering condition changed, other sample was also by method manufacturing shown in Figure 7.And, by from the absorbing material of making previously, removing flimsy material, and adopt new flimsy material layer, in laboratory, add water then and, make other sample at dull and stereotyped forcing press heating sample.

As later detailed description, when sample bears the tension force that vertically acts on the sample plane, the crack resistance of test sample or laminarity.As pointing out in detail that later on log also compares.Analysis result shows that adding water has improved bonding between the flimsy material layer that absorbs the flimsy material part and the bottom.And, utilize specific calendering condition to improve cohesiveness in a way.

Determine to have the layering process of the test of delamination strength of the absorbent core part of flimsy material layer

Determine the layering of sample or the tensile strength of splitting according to the process of the test that proposes below.Test is used for estimating the bondability that exists between the carrying flimsy material layer of absorbing material sample and remaining absorbent core divide.If act on the sample perpendicular to sample plane when tension force, split or draw back in the interface place of sample between flimsy material and absorbent core divide, and bonding strength is directly corresponding to the tension force of maximum effect then.Yet if sample splits rather than splits at flimsy material/core intersection at in-core, the breaking resistance with core is the same big at least in the bonding strength of flimsy material core intersection so.

A kind of tension force/compression test of Instron board is used for applying tension force on the circular specimen of one 2 inch diameter, and this circular specimen is the laminated product of flimsy material layer and absorbent core part, and this power applies perpendicular to the plane of sample.Tension force in the slurry surface action in a side of sample, at the opposite side of the right carrying flimsy material surface action of opposite face, up to being damaged at sample.This power is delivered to the surface of facing mutually of sample from testing equipment, and this sample is fixed on two-sided tape on the metal platen of machine, will describe in detail this later on.

This layering test makes the necessary tension force quantification of splitting of the sample in the absorbent core part, perhaps at carrying flimsy material and absorbent core intersection partly, if less than the intensity of absorbent core part itself, making at this sample necessary tension force that splits, this intersection bonding strength quantizes.Bondability or bonding strength between the slurry of flimsy material layer and absorbent core part depend on many variations.Wish to have the bonding or bonding of minimum degree to keep the product globality.For the material of accept handling at interpreter subsequently, this is correct especially, and the product that the material in this interpreter is used for absorbent article is diaper or feminine hygiene products for example.

Use in test following article:

A) model is the tension force/compression test (Reference numeral is 600 among Fig. 8) of 554201 Instron board and the special-purpose computer that the software kit of the Merlin board that Instron provides is housed;

B) 50 newton's tension force/compressive load sensor (Reference numeral among Fig. 8 is 610);

C) pivot fitting of the Instron board of last fixation clip;

D) model is ATOM-SE 15 Hudson Machinery Worldwide hydraulic presses (Reference numeral is 620 among Figure 11);

E) 2 inch diameter circular mode (Reference numeral is 630 among Figure 11);

F) 3M Scotch board two-sided tape (#41010DSLD01AC502D);

G) has the circular brass top board (Reference numeral is 650 among Fig. 8 and 9) of the clamp surface of 1.978 inch diameter D1; With

H) has lower platen (Reference numeral is 660 among Fig. 8) greater than 2 inches diameter.

At first, to adapt to the controlled environment condition be to keep minimum 2 hours under 23 ± 1 ℃ temperature and 50% ± 2% the relative humidity to the material that uses of sample.The arithmetic product of thickness, length and width by calculating volume of sample such as measured sample is determined measured weight the density of sample material then divided by the volume of sample.

Prepare a sample material, so as it at least 18 inches long, wide greater than 2 inches.As an alternative, obtain the sample material 720 (Figure 10) of enough small bores, so that form seven (7) individual circular specimens thus, each has 2 inch diameters.

Then, sample material 720 is placed to its flimsy material layer 722 and places stayed surface 750 times (Figure 10).The paper that gets loose removes (Figure 10) from an only side of the length of Scotch board 3M two-sided tape 760.The adhesive side of the exposure of adhesive tape 760 acts on the slurry side (Figure 10) towards last exposure of sample material 720.At this moment, the top surface paper 762 (Figure 10) that gets loose is stayed on the adhesive tape 760 in place.

Then, as shown in figure 11, the sample material 720 with jointing tape 760 is placed on the bed 770 of hydraulic press, so that bearing bed (flimsy material layer) side is downward, adhesive tape gets loose the paper side upwards.Circular specimen 720 ' (Figure 12) utilizes 2 inch diameter circular mode, 630 cross cuttings of hydraulic press 620.Cross cutting sample 720 ' has cross cutting flimsy material 722 ' in the bottom surface, and has the cutting part of the adhesive tape 760 ' that also is connected to the top and the paper 762 ' that gets loose, and therefore as described below, after erecting testing machine, sample 720 ' can be installed on the testing machine subsequently.

For having splitting or the typical sample of layering tensile strength between 2 newton and 11 newton, 50 newton's tension force/compressive load sensor 610 (Fig. 8) are installed on the Instron board testing machine crosshead, so that suitable sensing to be provided, and has sufficiently high rated value simultaneously, so that bear initial compressive load, this moment, top board 650 initially moved down so that at first force sample 720 ' to withstand lower platen 660 between the adhesive tape, thus make sample 720 ' as following detailed description bond on the pressing plate.

The circular metal lower platen 660 (Fig. 8) that has greater than 2 inch diameters (for example 8 inches) is used as fixture under the machine of Instron board.

Start computer, open Merlin board software.The vertical demixing test of compression method is classified in selection as, to start Instron board machine." preceding cycle " parameter below setting:

Crosshead speed: 75mm/ branch; With

Greatest limit: 35 newton's load (as following detailed description, the compressive load of sufficient to guarantee firm gluing fixedly sample 720 ' on upper and lower pressing plate).

Second Scotch board 3M two-sided tape 680 (Figure 14) are placed on the lower platen 660.Particularly, the paper that gets loose removes from the bottom side of bar shaped adhesive tape 680, a position, the bonding bottom side of adhesive tape 680 is adhered on the lower platen 660 (Figure 14), therefore, when top board 650 is installed subsequently, the whole surface of top board and second adhesive tape 680 vertical registration on the lower platen 660.Then, the paper 690 that gets loose is removed from the top side towards last of the second adhesive tape 680 of lower platen 660.

The cross cutting sample 720 ' for preparing previously then is connected (Figure 13) with top board 650.Its realization is by the top side paper 762 ' that gets loose is removed from the adhesive tape 760 ' on the sample 720 ', so that expose the adhesive side of adhesive tape 760 ', sample is pressed onto on the surface of last circular brass pressing plate 650 of 2 inch diameters with the connection adhesive tape then.

Then, on Instron board machine 660, in the fixture, hold in the connection (the Instron catalog number (Cat.No.) is 2301-115), have the last circular brass pressing plate 650 that connects sample 720 ' alignment pin is installed in self-adjustment.

Then, Instron board machine 600 is regulated to locate circular brass pressing plate 650, so that the distance of circular pressing plate 660 is 2.5 inches under its distance.

Set Instron board machine measuring length then.

Checking the equipment, is minimum to guarantee that any random sample moves.

The load of Instron board machine is come balance by pushing " balance " switch.

By pushing " startup " switch activated test.

In process of the test, top board 650 will be downwards towards lower platen 660 initial movable, up to 35 newton's force compresses sample 720 ' (Figure 15) forming the bonding of top board 650, two-sided tape 760 ' and sample 720 ', and form the bonding of lower platen 660, two-sided tape 680 and sample 720 '.After reaching 35 newton's pressure, the moving direction automatic reverse of top board 650, top board 650 will leave lower platen 660 and move up with the speed that 75mm/ divides, and sample will split or layering (Figure 16).

During pressing plate 650 leaves pressing plate 660 and moves, sample 720 ' will pressurize under the stretch-draw pattern.In the stretch-draw mode process, the amplitude peak of tension force corresponding to sample 720 ' split or layered portion between bondability (Figure 16).This shows or flimsy material (bearing bed) and core (if flimsy material and core layering) between bonding strength, the perhaps intensity of core itself, if the bonding strength between bearing bed and the core greater than the intensity of core own, itself splits core.

Sample 720 ' split or layering after, top board 650 removes from Instron board machine 600, sample coupon removes from top board and lower platen.

As mentioned above, new sample can prepare and be installed on the top board, and then, top board reinstalls on the Instron board machine, and returns to measuring length by pushing " recovery " switch.

Seven samples are done experiment.Write down splitting or stratification forces (this is the positive peak in the force curve that is produced by graph making software) of each sample in seven samples, and calculating mean value.Typical force curve is represented in Figure 17.

Other tests and measurement

Determine the sample that other physical property of material, this material are used to split or delamination strength is tested by additional test.

Determining of basic weight

By sample is weighed first, determine to choose the basic weight of the absorbing material of delamination strength test sample by sample material.Measure the length and the width of sample.Length multiply by reference area mutually with width.Weight is divided by area then, and its merchant is a basic weight.

Determining of density

By sample is weighed first, determine to choose the density of the absorbing material of delamination strength test sample by sample material.Measure length, width and the thickness of sample, and make it multiply by volume calculated mutually.Sample weight is divided by volume, with bulk density then.

Determining of Gurley rigidity

Determine to choose " the Gurley rigidity " of the absorbing material of delamination strength test sample by sample material, this sample material is tested according to the traditional Gurley stiffness test that is used for non-woven absorption fiber art.The Gurley stiffness test machine (4171E model) that utilizes the Gurley PrecisionInstruments of USA New York Troy to make is measured the Gurley rigidity value of absorbing material.This apparatus measures is required adds moment of flexure, and with the given bending of the specific dimensions that produces the test sample bar, this test sample bar is at one end fixing, and has the concentrfated load that applies at the other end.The result is unit " Gurley rigidity " value with the milligram.The rigidity of material is high more, and the elasticity of material is low more, and pliability is also low more.

Tensile strength

Determine to choose the tensile strength of the absorbing material of delamination strength test sample by sample material, this sample material is tested according to the traditional tensile strength test that is used for non-woven absorption fiber art.Indicate according to the disposable and non-woven association in Europe (" edana ") and ISO9073-3:1989 (EN 29073 the 3rd part) and the test of tensile strength 20.2-89 longitudinally on sample plane, to apply the tensile strength value that power is determined the material of Rack and length by constant rate of speed with regulation.

Five (5) individual elongated sample materials cut into length and are parallel to the material machine direction.Each test specimen is that 50 ± 0.5mm is wide, and has enough length, separates with the clamp that allows 200mm.Test sample is a condition with ERT 60.1-75.Pulling test machine (dynamometer) applies the constant extension speed that 200mm/ divides, and this pulling test machine is at initial alignment composition fixation test sample between the stretch-draw machine clamp of 200 ± 1mm.Record power-extension curve.The highest deviation value by the power of reading-extension curve is determined tensile strength.

Example

Example 1

On the sample of the absorbing material of structure, carry out strength test according to above-mentioned test with material shown in Figure 6 520.In example 1, except injector arrangement 150 water spray add do not work, choose sample in the material 520 of the embodiment manufacturing by method shown in Figure 7.Like this, in processing procedure, water does not add in the material.

The material of making 520 has the upper strata 529 that (1) has 42gsm (gram/square metre) basic weight and 0% superabsorbent polymer (" SAP "), (2) have 89gsm basic weight and the middle level 526 of comparing the superabsorbent polymer of 47.7% percentage by weight with the weight of pulp fibres in the middle level, have 102gsm basic weight and the bottom 524 of comparing the superabsorbent polymer of 45.7% percentage by weight with the weight of pulp fibres in the bottom with (3).

In each sample, top layer 529 and middle level 526 comprise slurry, and this slurry is the slurry that 100% southern loose brown paper was handled.Bottom 524 comprises south pine slurry, the mixture of the slurry of the brown paper processing of the slurry of the brown paper processing that this south pine slurry is 84% percentage by weight and the cold alkali treatment of 16% percentage by weight, wherein cold alkali treatment is that the application number in application on above-mentioned January 18 nineteen ninety-five is to define in 08/370571 the U.S. Patent application, and as mentioned above referring to the pulp fibres of the layer 24,26 and 28 that is used for absorbing material shown in Figure 2 20.

Superabsorbent materials 540 in example 1 sample material is into the form of particulate, it is by Stockhausen GmbH, Krefeld, Germany sells with title 7440, and there is office in the said firm in the 2401Doyle street of the Greensboro of American South Gary Fu Niya 27406.

The flimsy material layer 522 of material 520 is the outer lining of rolling, to be used as the clad can bed of material 62 in the method shown in Figure 7.Flimsy material is by Cellu Tissue Corporation, 2 Forbes streets, and East Hartford, Connecticut 06108, and USA sells.The flimsy material of four kinds of different brackets is used to provide multi-form absorbing material 520: flimsy material grade 3007, flimsy material grade 3007X, flimsy material grade 3007Y and flimsy material grade 3008.Each flimsy material grade is by 100% southern softwood manufacturing, and each grade has the advantages that to propose among the table 1A, and wherein " MD " refers to that flimsy material makes the line machine direction, and " CD " refers to that flimsy material makes the line cross-directional.

Table 1A

Grade	??3007	??3007X	??3007Y	??3008
Grade	??3007	??3007X	??3007Y	??3008	Basic weight (pound/300 square feet)	??10-10.5	??10	??11.7-12.3	??10.0-11.0
Bulk density (.000 inch)	??-	??76-89	??-	??-	Basic weight (pound/300 square feet)	??10-10.5	??10	??11.7-12.3	??10.0-11.0
Bulk density (.000 inch)	??-	??76-89	??-	??-	MD tension force (gram/inch) is done	??475-575	??496-518	??475-575	??250-275
CD tension force (gram/inch) is done	??90-125	??101-105	??90-125	??50-60	MD tension force (gram/inch) is done	??475-575	??496-518	??475-575	??250-275
CD tension force (gram/inch) is done	??90-125	??101-105	??90-125	??50-60	MD tension force (gram/inch) is wet	??-	??104-118	??-	??-
CD tension force (gram/inch) is wet	??-	??-	??-	??-	MD tension force (gram/inch) is wet	??-	??104-118	??-	??-
CD tension force (gram/inch) is wet	??-	??-	??-	??-	??ELONGATION?????(％) ??(@MD?BREAK)	??12.18	??24	??22-28	??22-28
Porosity (foot ³/ Min/ foot ²)	??200-276	??273-312	??-	??285	??ELONGATION?????(％) ??(@MD?BREAK)	??12.18	??24	??22-28	??22-28
Porosity (foot ³/ Min/ foot ²)	??200-276	??273-312	??-	??285	Brightness (reflectivity 457 nm)	??-	??86.4-86.7	??-	??78
Absorptivity (second)	??-	??-	??-	??1-9	Brightness (reflectivity 457 nm)	??-	??86.4-86.7	??-	??78
Absorptivity (second)	??-	??-	??-	??1-9	Absorbability (X/ deadweight)	??-	??-	??-	??-
Humidity (%)	??-	??7.9	??-	??4.6-6.0	Absorbability (X/ deadweight)	??-	??-	??-	??-
Humidity (%)	??-	??7.9	??-	??4.6-6.0	Fluorescence (not allowing)	??-	??-	??-	??-

The embodiment of method shown in Figure 7 is used for making four (4) one-time continuous production length overalls of absorbing material shown in Figure 6 520, and each one-time continuous production length overall has different one of them in four grade flimsy materials that table lists among the 1A.Therefore sprinkler 150 inoperation, do not have water to add.This method is operated with 90 meters/minute linear velocity.Top roll 121 and lower roll 122 all keep 150 ℃ temperature.Outer lining is in compacting between

roller

121 and 122 under the load of 315 ft lbfs/linear inch.Top roll 121 has smooth surface, and lower roll 122 is " flax " rollers with rough surface.

From four one-time continuous production length overalls each, the sample of preparation seven (7) individual samples, and test according to above-mentioned layering process of the test.For each one-time continuous production length overall, the test value of stratification forces (be sample split power) is asked on average, so that single average stratification forces to be provided.Under tabulate among the 1B, (name is called sample one-time continuous production length overall 1 to four one-time continuous production length overalls, sample one-time continuous production length overall 2, sample one-time continuous production length overall 3, with sample one-time continuous production length overall 4) in each, list and be called as the average stratification forces of " average delamination strength ".

Table 1B also is listed in the basic weight of the specimen material in each one-time continuous production length overall, the tensile strength of Gurley rigidity and its machine direction.

Table 1B also comprise May Day time continuously the production length overall average layering test power and the 6th one-time continuous production length overall of seven (7) individual samples that promptly be labeled as the contrast one-time continuous production length overall of " contrast one-time continuous production length overall 1 " promptly be labeled as the average layering test power of seven (7) individual samples of the contrast one-time continuous production length overall of " contrast one-time continuous production length overall 2 ".Contrast one-time continuous production length overall 1 and contrast one-time continuous production length overall 2 materials are by the said method manufacturing of four one-time continuous production length overalls, except contrast one-time continuous production length overall 1 and contrast one-time continuous production length overall 2 are not used down flax roller 122, sample one-time continuous production length overall 1,2,3 and 4 data produce thus.What replace is that the lower roll 122 of contrast one-time continuous production length overall 1 and contrast one-time continuous production length overall 2 is smooth surface roller shape top rolls 121.Contrast one-time continuous production length overall 1 material comprises 3007 grade flimsy materials, and contrast one-time continuous production length overall 2 materials comprise 3008 grade flimsy materials.The composition of absorbent core part is identical in contrasting one-time continuous production length overall 1 and contrasting one-time continuous production length overall 2, and divides identical with the absorbent core of sample one-time continuous production length overall 1,2,3 and 4.

Table 1B

Sample one-time continuous production length overall mark	Basic weight (gram/rice ²)	Density (gram per centimeter ³)	GURLEY rigidity (milligram)	Machine direction tensile strength (newton)	The flimsy material grade	The average delamination strength (newton) of seven samples	Remarks
Sample one-time continuous production length overall mark	Basic weight (gram/rice ²)	Density (gram per centimeter ³)	GURLEY rigidity (milligram)	Machine direction tensile strength (newton)	The flimsy material grade	The average delamination strength (newton) of seven samples	Remarks	Sample one-time continuous production length overall 1	??247	??0.27	??164.6	??11.53	?3007	?2.61	Flimsy material is easy to break away from
Sample one-time continuous production length overall 2	??250	??0.27	??210.4	??12.66	?3007X	?4.52	The flimsy material that breaks away from is peeled off some fibre from core	Sample one-time continuous production length overall 1	??247	??0.27	??164.6	??11.53	?3007	?2.61	Flimsy material is easy to break away from
Sample one-time continuous production length overall 2	??250	??0.27	??210.4	??12.66	?3007X	?4.52		Sample one-time continuous production length overall 3	??260	??0.28	??203.9	??16.29	?3007Y	?5.78	Flimsy material is peeled off many fibers and SAP
Sample one-time continuous production length overall 4	??245	??0.26	??181.1	??12.16	?3008	?5.12	The flimsy material that breaks away from is peeled off some fibre from core	Sample one-time continuous production length overall 3	??260	??0.28	??203.9	??16.29	?3007Y	?5.78	Flimsy material is peeled off many fibers and SAP
Sample one-time continuous production length overall 4	??245	??0.26	??181.1	??12.16	?3008	?5.12		Contrast one-time continuous production length overall 1 (smooth roll)	??251	??0.29	??192	??11.43	?3007	?2.66	Flimsy material is easy to break away from
Contrast one-time continuous production length overall 2 (smooth roll)	??250	??0.27	??180	??11.70	?3008	?2.17	Flimsy material is easy to break away from		??251	??0.29	??192	??11.43	?3007	?2.66	Flimsy material is easy to break away from

Value among the table 1B shows the power value of delamination strength, and under this power value, flimsy material breaks away from absorbent core (being that flimsy material layer 522 separates with absorbent core part bottom 524).These values are at the sample material that does not add water in manufacture process (i.e. the interpolation of water in Fig. 7 equipment 150 is not worked).Result of the test shows that the flimsy material of different brackets breaks away from the absorbent core part under less than 6 newton's stratification forces effect.

It shall yet further be noted that utilization and smooth roll are in a ratio of rough roller or flax roller can increase delamination strength.For example, in contrast one-time continuous production length overall 2 (utilizing smooth roll), delamination strength only is 2.17 newton for the outer lining with grade 3008 flimsy materials, but in sample one-time continuous production length overall 4 (utilization has following flax roller of non-smooth surface), delamination strength bigger for outer lining (i.e. 5.12 newton) with grade 3008 flimsy materials.

Like this, the part combination for flimsy material of handling with flax roller and core utilizes non-smooth roll to increase the bonding delamination strength of flimsy material/core.The increase of this delamination strength does not even need to add moisture, below at once will in example 2, describe the influence of moisture interpolation itself in detail.

Example 2

The influence of moisture is added in investigation to flimsy material during the method for making absorbing material below.In example 2, the embodiment of method shown in Figure 7 and above-mentioned example 1 the same operation, but for the one-time continuous production length overall of using three different flimsy materials, water is injected on the flimsy material layer outer lining, for two other " contrasts one-time continuous production length overall ", water is not injected on the flimsy material.Table 2 has been listed the characteristics of the material of making in each one-time continuous production length overall in example 2.

The one-time continuous production length overall of example 2 upper strata 529, middle level 526 and the bottom 524 of absorbent core part 536 have slurry and the superabsorbent thing composition identical with example 1.Processing line (Fig. 7) is with speed identical with example 1 and identical calender roll temperature and pressure operation.For the sample one-time continuous production length overall 1,3 and 4 in the table 2, water is ejected into the bottom of flimsy material layer outer lining 62 from the nozzle (Fig. 7) of said apparatus 150, this bottom distance of 10 inches below outer lining 62.Six nozzles separate 30 centimetres of distributions along the width center of outer lining.Water is with the temperature of 15psig pressure and 15 ℃ and with the certain speed supply nozzle, so that made 3% moisture addition based on absorbing material outer lining weight before adding moisture.

Just after outer lining passed calender roll, the wet amount of outer lining was low.Yet after sample and ambient atmosphere reached balance, the measuring of the moisture in the material in each sample one-time continuous production length overall 1,3 and 4 showed that wet measurer has in the scope of from 4% to 4.5% percentage by weight of gross weight of sample of the moisture that comprises.

For contrast one-time continuous production length overall of listing in the table 21 and contrast one-time continuous production length overall 2,

calender roll

121 and 122 is smooth.

The sign of the flimsy material grade of using in the one-time continuous production length overall of the example of listing in table 22 is corresponding to the example 1 flimsy material grade of listing among the superincumbent table 1A.

Be used for determining the contrast one-time continuous production length overall 2 of the average delamination strength in the table 2 for test, flimsy material at first manually removes in laboratory before test, therefore, only absorbent core is partly carried out the delamination strength test.

Owing to lack the pot life in production equipment, can not make the sample one-time continuous production length overall 2 of utilizing grade 3007X flimsy material.Like this, table 2 is not listed sample one-time continuous production length overall 2.

Table 2

Sample one-time continuous production length overall mark	Basic weight (gram/rice ²)	Density (gram per centimeter ³)	GURLEY rigidity (milligram)	Machine direction tensile strength (newton)	The flimsy material grade	The average delamination strength (newton) of seven samples	Remarks
Sample one-time continuous production length overall mark	Basic weight (gram/rice ²)	Density (gram per centimeter ³)	GURLEY rigidity (milligram)	Machine direction tensile strength (newton)	The flimsy material grade	The average delamination strength (newton) of seven samples	Remarks	Sample one-time continuous production length overall 1	?253	?0.29	?185.7	?17.52	?3007	??7.78	Replacement is from the core of the layering of the flimsy material of core disengaging
Sample one-time continuous production length overall 3	?260	?0.29	?217.1	?17.87	?3007Y	??8.40	Replacement is from the core of the layering of the flimsy material of core disengaging	Sample one-time continuous production length overall 1	?253	?0.29	?185.7	?17.52	?3007	??7.78
Sample one-time continuous production length overall 3	?260	?0.29	?217.1	?17.87	?3007Y	??8.40		Sample one-time continuous production length overall 4	?255	?0.29	?195.0	?14.69	?3008	??7.86	Replacement is from the core of the layering of the flimsy material of core disengaging
Contrast one-time continuous production length overall 1 (smooth roll)	?251	?0.29	?192	?11.43	?3007	??2.66	Flimsy material from the core disengaging	Sample one-time continuous production length overall 4	?255	?0.29	?195.0	?14.69	?3008	??7.86
	?251	?0.29	?192	?11.43	?3007	??2.66	Flimsy material from the core disengaging	Contrast one-time continuous production length overall 2 (smooth roll)	?237	?0.27	?-	?-	?3007	??3.42	The core of layering (flimsy material manually removes from sample before test)

Table 1B and table 2 can compare, with the effect that shows that moisture adds.When adding moisture, the bonding strength between flimsy material and absorbent core divide increases.Table 1B is illustrated in sample one-time continuous production length overall 1,2,3 and 4 and does not add water, and flimsy material breaks away from core before the core layering.On the other hand, table 2 is illustrated in sample one-time continuous production length overall 1,3 and 4 and has added water, flimsy material bonding securely so that its can not break away from, replace the core of layering.

Table 2 is illustrated in also in the process of method shown in Figure 7 that the globality of absorbent core part (part 536 among Fig. 6) itself significantly improves when adding water.Contrast one-time continuous production length overall 2 in table 2 is made under the situation of not adding water, and before carrying out the layering test on the sample of contrast one-time continuous production length overall 2, in laboratory, flimsy material manually removes.Contrast one-time continuous production length overall 2 sample cores split or layering under 3.42 newton's average delamination strength.This is significantly less than the average delamination strength of the sample of being tested of sample one-time continuous production length overall 1, sample one-time continuous production length overall 3 and sample one-time continuous production length overall 4, wherein outer lining is by adding water treatment, and core splits or layering under the average intensity value that surpasses 7 newton (being significantly higher than 3.42 newton's of contrast one-time continuous production length overall 2 samples average core delamination strength value).

Example 3

The effect that example 3 investigation are sprayed water on flimsy material under laboratory scale.Use has the absorbing material of structure shown in Figure 6, and that describes in the composition of absorbing material and example 1 and the example 2 is different.Particularly, the material 520 (Fig. 6) that uses in example 3 manufactures and has: the upper strata 529 with 25gsm basic weight and 0% superabsorbent polymer; Have 225gsm basic weight and the middle level 526 of comparing the superabsorbent polymer of 57% percentage by weight with the weight of pulp fibres in the middle level; And have 233gsm basic weight and the bottom 524 of comparing the superabsorbent polymer of 54% percentage by weight with the weight of pulp fibres in the bottom.In each sample, top layer 529 and middle level 526 comprise slurry, and this slurry is the slurry that 100% southern loose brown paper was handled.Bottom 524 comprises south pine slurry, the mixture of the slurry of the brown paper processing of the slurry of the brown paper processing that this south pine slurry is 78% percentage by weight and the cold alkali treatment of 22% percentage by weight, wherein cold alkali treatment is that the application number in application on above-mentioned January 18 nineteen ninety-five is to define in 08/370571 the U.S. Patent application, and as mentioned above referring to the pulp fibres of the layer 24,26 and 28 that is used for absorbing material shown in Figure 2 20.The form of the 540 one-tenth particulates of superabsorbent materials in example 3, it is sold with above-mentioned title 7440 by Stockhausen.Flimsy material layer 522 (Fig. 6) is grade 3008 (top table 1A).

The absorbing material of example 3 prepares on processing line, and this schematically illustrates as Fig. 7, but does not have the operation of water adding set 150, so that anti-sealing adds on the outer lining of shaping.Processing line moves under 35 meters/minute speed.Top roll 121 and lower roll 122 all remain on 140 ℃ temperature.Top roll 121 and lower roll 122 smooth surfaces, and outer lining compacting between roller under the load of 315 ft lbfs/linear inch.After absorbing material is shaped, gather the materials samples that is shaped, the flimsy material layer manually removes from sample.New then flimsy material spare is placed on (the flimsy material grade 3008 among the table 1A) on the absorbent core.

In first sample, the sample 1 of example 3, the new flimsy material that does not add water 300 and the time be in heated press, to be adhered on the core under 60 seconds the pressure of 120psi.There is not water to add.

Except being placed at sample 2 before the forcing press of heating, the new flimsy material on the sample 2 with water spray with the weight of the oven-dried weight of the sample that moisturizes 4% outside, second sample, sample 2 prepares in the mode identical with sample 1.Then, moistening sample 2 under the condition identical with example 1 in heated press pressurized.

Except the water yield of adding is 11% percentage by weight of oven-dry weight of sample, the 3rd sample, sample 3 prepares in the mode identical with said sample 2.

At last, the preparation control sample, make the material of control sample except not adding water, before the layering test, remove outside the flimsy material then, control sample only is made up of absorbent core material, and this absorbent core material is made in the mode identical with 2 employed materials with making sample 1 on the processing line of Fig. 7.

The result of the delamination strength test of table 3 expression sample.The higher standard deviation of sample 2 is the heterogeneities owing to injection water in laboratory's spraying system.This causes the bonding variability between flimsy material and the core.The data representation of table 3 adds moisture and has improved the bonding of absorbent core part and flimsy material.

Table 3

Sample	Add the water yield	The average delamination strength (newton) of seven samples	Remarks
Sample	Add the water yield	The average delamination strength (newton) of seven samples	Remarks	Control sample	0% water	2.26, std.dev.=0.52	Do not use flimsy material.The core layering
Sample 1	0% water	0	Flimsy material is not adhered on the core	Control sample	0% water	2.26, std.dev.=0.52	Do not use flimsy material.The core layering
Sample 1	0% water	0	Flimsy material is not adhered on the core	Sample
2	4% water	4.80, std.dev.=1.55	Flimsy material breaks away from from core	Sample
2	4% water	4.80, std.dev.=1.55	Flimsy material breaks away from from core	Sample 3	11% water	------	Flimsy material and core excellent bonds

Under the situation of sample 1, between core and flimsy material, there be seldom bonding.Under the situation of sample 3, bonding fine of flimsy material and core, so that core at first separates, and bonding bigger power between flimsy material and core or intensity is energy measurement not.Yet,, have the bonding general trend that improves basically by adding water.

Example 4

The type of laboratory's investigation of describing in example 3 is to carry out in example 4, it at have with example 1 and 2 in material in the absorbing material of the identical structure as shown in Figure 6 that adopts and identical composition of layer (being superabsorbent thing percentage, kraft pulp and cold alkali treatment slurry percentage).The absorbing material of choosing example 4 test specimens initially with above-mentioned example 3 in identical mode make.

Yet the control sample of absorbent core is by the absorbing material preparation of not adding water of making on the processing line shown in Fig. 7, and flimsy material removes from core then.This control sample with below be called in the table 4 of " control sample " identical.

The absorbent core preparation that sample 1 is removed by hand by old flimsy material.New flimsy material (grade 3008) is placed on the core, assembly 300 and 120psi assigned 60 seconds and in heated press, pressurize.Do not add water.

Second sample, sample 2 is by the absorbent core preparation of having removed old flimsy material (grade 3008).New flimsy material (grade 3008) is placed on the absorbent core, and water is ejected on the flimsy material side of core, compares 11% percentage by weight so that wet amount is increased to the oven-dried weight of core.Then, assembly is with the mode hot pressing identical with the sample 1 of above-mentioned example 4.

Then sample is carried out the delamination strength test, the result proposes in following table 4.

Table 4

Sample	Add the water yield	The average delamination strength (newton) of seven samples	Remarks
Sample	Add the water yield	The average delamination strength (newton) of seven samples	Remarks	Control sample	0% water	2.98, std.dev.=0.53	Do not use flimsy material.The core layering
Sample 1	0% water	0	Flimsy material is not bonding with core	Control sample	0% water	2.98, std.dev.=0.53	Do not use flimsy material.The core layering
Sample 1	0% water	0	Flimsy material is not bonding with core	Sample
2	11% water	7.00, std.dev.=2.7	Flimsy material breaks away from from core	Sample

The delamination strength of the material of table 4 expression interpolation water is lower than the delamination strength of the material that adds water.

Under the situation of sample 1, between core and flimsy material, exist very little bonding.And, because the restriction of test spraying system can not be added the water than 11% low dosage.Therefore, the water filling of use 11%.The higher standard deviation of sample 2 is because the heterogeneity of water spray produces.This causes some the bonding variabilities between flimsy material and the core.This data representation adds moisture and has improved the bonding of absorbent core part and flimsy material.

The effect that moisture adds on absorbing material

As mentioned above, be called in name in the part of " manufacture method and equipment: first embodiment ", moisture (for example steam or water spray) can add on the absorbing material, formation with the mutual hydrogen bonded of influence pulp fibres in core segment (slurry layer), and the hydrogen bonded between flimsy material layer and the core segment pulp fibres, so that increase the intensity and the globality of the absorbing material of finishing.Have been found that on the contrary with traditional expectation, moisture adds and can significantly not increase the rigidity of finishing material.Manufacturing increases globality and intensity by hydrogen bonded but the absorbing material of finishing that do not increase rigidity is wished very much, and the material here is used for having soft and flexible absorption product for example disposable diaper and feminine hygiene.

Sample to absorbing material carries out the strength and stiffness test.Part sample does not after tested have the moisture of interpolation, and the part sample is done experiment after adding moisture.Expression in the result of the test table 5 below.

Table 5 is listed the value of Gurley rigidity and machine direction tensile strength, and this value is definite by the different tests sample of Sample A material, sample B material and contrast material being done experiment come.For each Sample A, sample B and contrast material, six test specimens are carried out the test of Gurley rigidity value, calculating mean value is also listed in table 5.For each Sample A, sample B and contrast material, five samples are done the machine direction tensile strength test, calculating mean value is also listed in table 5.Carry out the Gurley stiffness test according to the method that in above-mentioned " determining of Gurley rigidity " by name part, proposes, carry out the machine direction tensile strength test according to the method that in above-mentioned " tensile strength " by name part, proposes.

The Sample A material of listing in table 5, sample B material and contrast material are initially chosen in the absorbing material according to the method manufacturing described in the example 3 that proposes above.Do not spray water during the material that in initial manufacturing table 5 test, uses like this.Yet different with example 3, the flimsy material layer is not to remove by hand in the employed production material of finishing from table 5 test.

The control sample of table 5 is selected from the production material of handling without further, and determines Gurley rigidity value and the machine direction tensile strength value listed through testing in table 5.

For the sample of the Sample A of table 5, before carrying out rigidity and strength test, water is ejected into each sample top slurry layer and goes up (being the upper strata 529 among Fig. 6), so that wet amount increases to 5% of initial dry sample weight.Then, the sample of Sample A 300 and 120psi pressure under and in the heated plate forcing press pressurized 30 seconds.

Sample for the sample B of table 5, before carrying out rigidity and strength test, new additional thin tissue layer is used for top slurry layer (being the upper strata 529 of Fig. 6), sprays water on the surface of the exposure of the new flimsy material layer of each sample then, so that wet amount increases to 5% of initial dry sample weight.Act on additional flimsy material on the top layer and be with bottom on flimsy material same type (being the flimsy material grade 3308 that in table 1A, identifies as mentioned above in the reference example 3).Then, the sample of sample B 300 and 120psi pressure under and in the heated plate forcing press pressurized 30 seconds.

For each Sample A, sample B and contrast material, six samples to be measured to determine basic weight and density, the mean value of calculating basic weight and density is also listed in table 5.For Sample A, sample B material, after removing, heated press determines basic weight and density at sample.Determine the basic weight listed in the table 5 according to the method that in above-mentioned by name " determining of basic weight " part, proposes.Determine the density listed in the table 5 according to the method that in above-mentioned by name " determining of density " part, proposes.

Table 5 shows that the mean value of the tensile strength of contrast material (not adding water) is 15.57 newton.Be 25.42 newton and 27.25 newton's Sample A and sample B contrast with average tensile strength value respectively, 15.57 newton's of contrast material intensity is obviously little.The tensile strength of adding moist Sample A and B material is at least than the tensile strength of the contrast material that does not add moisture about 63%.And, undesirably, to compare with contrast material, the Gurley rigidity of Sample A and B material is not increased to any degree significantly.For sample B, increase less than 0.01%, for Sample A (second top layer that comprises flimsy material), increase less than 3.5%.Like this, the moisture of interpolation is convenient to the formation of hydrogen bonded, and the intensity that hydrogen bonded has increased material can desirably increase rigidity simultaneously.Even in the sample B material sample, add extra (second) layer flimsy material, to compare with contrast material, rigidity increases indistinctively.

Table 5

The sample sign	Basic weight (gram/rice ²)	Density (gram per centimeter ³)	GURLEY rigidity (milligram)	Machine direction tensile strength (newton)
The sample sign	Basic weight (gram/rice ²)	Density (gram per centimeter ³)	GURLEY rigidity (milligram)	Machine direction tensile strength (newton)	Sample A	?532	?0.41	?1253	?25.42
Sample B	?530	?0.39	?1213	?27.25	Sample A	?532	?0.41	?1253	?25.42
Sample B	?530	?0.39	?1213	?27.25	Contrast	?552	?0.36	?1212	?15.57

Under the prerequisite of the real essence of notion that does not exceed novelty of the present invention or principle and scope, obviously front detailed description of the invention and diagram thereof can be carried out a large amount of variations and modification.

Claims

1. method of making absorbing material, it comprises the steps:

A) formation has the outer lining of one deck at least, and this layer comprises the cellulose fibre that does not add Chemical Felter and thermosetting adhesive;

B) by add weight be before the humidification outer lining gross weight about 1% and about 8% between moisture, increase described web density; With

C) afterwards, at the real described outer lining of the temperatures of a rising, so that further increase web density in step (B).

2. method according to claim 1 is characterized in that, its step also comprises, in step (A) following steps before:

(1) from about 15 ℃ to about 60 ℃ temperature, water becomes aqueous solution of alkali metal salt to handle to comprise the liquid suspension of the slurry of described cellulose fibre to reach about 5 minutes to about 60 minutes a period of time, this water become aqueous solution of alkali metal salt have described solution from about 2% alkali metal salt concentration to about 25% percentage by weight; With

(2) utilize controlled atmosphere circulation and mechanical agitation that described cellulose fiber peacekeeping superabsorbent materials is mixed, to form the mixture of cellulose fiber peacekeeping superabsorbent materials.

3. method according to claim 1 is characterized in that, step (B) comprises low-pressure steam is sprayed near in the capsule of described outer lining one side, perhaps facing to the side water spray of described outer lining.

4. method according to claim 1 is characterized in that, step (C) comprising:

The described outer lining of compacting between two calender rolls, wherein the temperature of these two rollers is maintained at about in the scope between 70 ℃ and about 200 ℃, and one of them described roller has smooth surface, and another described roller has the surface of band indentation; With

Under the load effect between the horizontal outer lining width about 160 of per inch and about 2284 ft lbfs between described roller the described outer lining of compacting.

5. method according to claim 1 is characterized in that, its step (A) comprises the described outer lining of formation, and this outer lining comprises bearing bed, and this bearing bed is provided with the mixture of the described cellulose fibre of one deck at least.

6. absorbing material, its

(I) make by the method that comprises the following steps:

(B) the wet amount of described outer lining increase to weight be before the humidification outer lining weight about 1% and about 8% between; With

(C) afterwards, at the real described outer lining of the temperatures of a rising,, and realize increasing the bonding of described flimsy material and described at least one absorbed layer so that further increase web density in step (B); With

(II) it has the bonding strength between described flimsy material layer and described at least one absorbed layer, and this bonding strength surpasses 3 newton's test stratification forces.

7. absorbing material as claimed in claim 6, it is characterized in that, step (C) is included in the described outer lining of compacting between two calender rolls, wherein the temperature of these two rollers is maintained at about in the scope between 70 ℃ and about 200 ℃, and one of them described roller has smooth surface, and another described roller has the impressed rough surface of qualification, described indentation has 5% the degree of depth greater than the thickness of described flimsy material layer, so that contact with described flimsy material, thereby the some parts of described flimsy material is imbedded in described at least one absorbed layer, and described outer lining is compacted between described roller under the load effect between the horizontal outer lining width about 160 of per inch and about 2284 ft lbfs.

8. absorbing material, it is made by the process that comprises the steps, and the step of this process is:

(B) add water for described outer lining, so as the wet amount of described outer lining increase to weight be before the humidification outer lining weight about 1% and about 8% between; With

(C) afterwards in step (B), at the real described outer lining of the temperatures of a rising,, and make outer lining material tensile strength increase at least 60% so that further increase web density, make this material with omission step (B) simultaneously and compare, Gurley rigidity is increased surpass 0.01%.

9. absorbing material, it comprises:

Outer lining with a bearing bed is provided with at least one absorbed layer on this bearing bed, this absorbed layer comprises the cellulose fibre at least that does not add Chemical Felter and thermoset adhesive

Described outer lining has the density between about 0.25 gram/cubic centimetre and about 0.5 gram/cubic centimetre;

Described outer lining have about 150 the gram/square metre and about 600 the gram/square metre between basic weight;

Described outer lining has less than about 1500 milligrams Gurley rigidity;

Described outer lining has the machine direction tensile strength greater than about 9 newton; With

Described outer lining has tests the bonding strength of stratification forces greater than 3 newton between described at least one absorbed layer and described bearing bed.

10. absorbing material as claimed in claim 9 is characterized in that:

From about 15 ℃ to about 60 ℃ temperature, the liquid suspension that water becomes aqueous solution of alkali metal salt at first to handle the slurry that comprises described cellulose fibre reaches about 5 minutes to about 60 minutes a period of time, this water become aqueous solution of alkali metal salt have described solution from about 2% alkali metal salt concentration to about 25% percentage by weight, come the described cellulose fibre of fabrication portion thus;

Described at least one absorbed layer comprise based on the gross weight of described at least one absorbed layer with described superabsorbent materials from about 10% superabsorbent materials to about 60% percentage by weight; With

Described outer lining comprises an absorbed layer of described cellulose fibre, and this cellulose fibre does not contain superabsorbent materials, and is arranged on the top of described at least one absorbed layer.