DE2339207A1 - AIRLINED FIBER WEB FOR USE IN DISPOSABLE CLOTHS OR THE SAME, AND METHOD OF MANUFACTURING THEREOF - Google Patents

Description

EIKENBERG & BRÜMMERSTEDT PATENT LAWYERS IN HANOVER

Kimberly-Clark Corporation 240/572

Airlaid fibrous web for use in we gwe rf bare cloths or the like, as well as processes for their production

The invention relates to an airlaid

Paserbahn with low web weight, especially made of cellulose fibers for use in disposable wipes or the like, At the same time, the invention provides a method for producing such a fiber web.

Pure we gwe rf bare face, handkerchiefs, Towels and similar products have hitherto been used throughout so-called "water-laid" fiber webs. This is to be understood as fiber webs that are after the for the

509807/0598

Papermaking common technique by depositing a aqueous pulp from cellulose fibers on an open-pored Wire screens are generated, initially the main part of the Water drips through the pores of the wire screen and that residual water is removed from the paserbahn either by drying or by a combination of drying and pressing will. During the removal of the water, however, strong, due to the capillary surface tension, arise Forces between the fibers which inevitably lead to a strong bond between the fibers. As a result this phenomenon · possess paserbahns, which after a water-laid Method made have a very unfavorable feel, i.e. they are hard, rough and stiff, not very fluffy and overall not gentle and soft. In addition, they also have poor absorbency. To these disadvantages To eliminate, water-laid fibrous webs are usually creped, which gives both the feel and the Absorbency can be improved somewhat because the excessive bonding of the pasers to one another is somewhat interrupted.

But creped water-laid paserbahns are not yet optimal either. On the one hand, the excessive bonding of the pasers to one another is not completely eliminated by creping, and on the other hand, water-laid pas webs have the fundamental disadvantage that the pasers are typically oriented in the machine direction, ie in the direction of movement of the screen. This will

509807/0598

the strength in the machine direction is always higher than in Direction across it. As a result, creped show what serge put Webs that have cross-machine direction strength is sufficient, generally an excessive machine direction strength, which in turn is the setting of a prevents optimal grip.

When the "disposable products are to be used in contact with moisture, such as Towels and facial tissues, it is common to still bring them with you to add certain agents which increase the wet strength, mostly plastics. This also improves the grip feeling of the products and sometimes also their absorption capacity.

Air-laid fiber webs, their manufacture for a number of years, e.g. from US Pat. No. 2,447,161 and 2 810 940 and GB-PS 1 088 991 are known, have the fundamental disadvantages of water-laid fiber webs not. The known air-laid fiber webs could, however, so far only be used for purposes in which either only a low strength was required (as e.g. for certain absorbent products) or where it only . a certain minimum strength and not the absorption properties were important (e.g. for certain Special paper). In addition, the speed is also with which the known fiber webs can be produced, not always sufficient for modern mass production.

509807/0598

-A-

In U.S. Patent 3,692,622 a vicarious iat described which allows to produce air-laid roads at relatively high speed. An air-laid continuum of fibers is generated on an open-pored wire screen, which is completely moistened on the wire screen and then transferred to a station in which the binding of the fibers is somewhat loosened. Moisture penetration of the fiber web, however, requires subsequent complete drying of the web, which is complex and expensive.

The invention aims to put an air pressure on

Fiber web with a low web weight, in particular made of cellulose fibers are created, which on the one hand the necessary for use for towels and the like disposable products:? Has strength and which, on the other hand, has excellent properties in terms of absorbency and feel. The invention is also intended to provide a method be specified, which allows the production of such a fiber web at high operating speed.

The fiber web according to the invention characterizes by the fact that a three-dimensional continuum is provided from fibers in the air-laid state, which is interrupted by individual, discrete adhesive-bonded areas distributed in a predetermined distribution pattern, with the adhesive-bonded areas versus the unbonded areas Areas to a strength that is many times less than the strength of the unbound areas,

509807/0598

BATH

are compressed and their distance from one another is smaller than the average length of the fibers, and wherein the adhesive is supplied from the outside and applied to the adhesive-bondedη Areas is limited.

For the production of such a fiber web

In a further embodiment of the invention, a method is provided which is characterized in that it is assumed that a fiber web of non-compressed, statistically oriented fibers laid dry air on a circulating open-pored wire screen, that this fiber web on the side remote from the wire screen with a decrease Element is brought into contact, which revolves at approximately the same speed as the wire screen and on its surface in a distribution pattern which corresponds to the distribution pattern of the adhesive-bonded areas in the end product, an adhesive F'Uissi ^ kiti ifc carries, which at the moment the contact of the decrease-moose in with the Yanerliihn quickly penetrates into this transverse to the plane of the orbit, incU "ß then the adhesive is solidified.

Under the handle "Klssatoff-PlIiBdi" iii? Lv ¹¹ -

is in the context of the invention a mixture of an adhesive and one as a solvent, dispersant, or plasticizer to understand acting liquid, the solidification of the adhesive with simultaneous removal of the liquid is done by heating the removal element. Alternatively, this term can also mean “fusible

509807/0598

and in 'meltable form adhesive' means its solidification by cooling the acceptance element happens.

The compression of the adhesive-bonded Areas such that the unbound areas of the Paserbahn have a layer thickness that is many times greater than that of the bound areas, and can be in different Way to be effected. For example, the adhesive bonded Areas by raised areas with the adhesive liquid coated protrusions on the take-off element should not be compressed. Alternatively, the Paserbahn are compressed as a whole when removed from the wire screen, whereupon after pressure relief only those not from the Adhesive-liquid-penetrated areas elastically their original layer thickness spring back, while the areas penetrated by the adhesive liquid die keep compressed layer thickness. Finally, however, it is also possible to compress the adhesive-bonded Areas a liquid softening the fibers, in the case of cellulose fibers preferably water, to be used as a component of the adhesive liquid, while removing the liquid for the purpose of solidifying the adhesive, the areas of the fiber web penetrated by the adhesive liquid by forces be compressed due to surface tension.

The fibrous web of the invention is a

lightweight product made of preferably ZeI IuI ο se fibers, which is excellent to use for! towels and

509807/0598

such disposable products are suitable. It owns as a result the adhesive bond has very good strength. Since the adhesive bond is only distributed in certain, discretely Areas is present and the unbound areas of the fiber web practically the original, air-laid state have retained, but at the same time are also the properties in terms of absorption capacity and feel optimal.

The method according to the invention allows

very high working speeds of e.g. more than 300 m / min. Such high operating speeds generally cause quite a difficulty in removing the fiber web from the wire screen, since an air laid fiber web is usually has no significant cohesion of the pasers. The creation of a sufficient fiber bond is also important usually difficult at high working speeds. In the process according to the invention, however, the penetrates Liquid component of the adhesive liquid practical at the moment of contact of the fiber web with the removal element immediately in the fiber web, whereby a temporary consolidation and thus improved cohesion of the fibers of the fiber web results in ". This temporary consolidation facilitates the removal of the fiber web from the wire screen and also the subsequent final solidification by setting the plastic. Otherwise, in the method according to the invention neither a subsequent dissolution of fiber bonds excessive drying of the fiber web is still necessary, as moisture is only minimal and only in limited parts.

509807/0598

BATH ORIGINAL

areas is applied to the fibrous web. In this context It is also important that the moisture does not get onto the wire rope, but into the fiber web later.

Details of the

Invention and its advantages in exemplary embodiments the drawings explained in more detail. In the drawings show:

Pig. 1 is a side view of a first

Embodiment of a device for carrying out the invention according to the invention Procedure,

Fig. 2 schematically in cross section that

end product produced with the device according to FIG. 1, and

3 and 4 show further embodiments in side view a device for carrying out the method according to the invention.

50980 7/0598

The one in Pig. The device shown in FIG. 1 goes from one to the other for producing an air-laid paserbane 10 paper web 12 made from wood pulp by wet means. This paper web 12 is unwound from a roll 16 and in a shredding device into their individual fibers divided up. For this purpose, the paper web 12 is fed into the shredding device by means of a pair of intake rollers 18, 20 moved in. The crusher itself is not Shown in detail, it contains a plucking roller driven in the direction of the arrow '22.

The strands 14 formed in the shredding device become substantially perpendicular running conveyor shaft 24 promoted downwards and arrive then onto an open-pored wire screen 26 moving past below the conveyor shaft at a constant running speed, on which they are placed in random orientation to form the Paserbahn 10. The promotion of the Pasern 14 to the wire screen 26 is brought about by an air flow supplied via a blow channel 28, the effect of which is supported is through one in the area of the end of the conveyor shaft Suction box 30 arranged below the wire screen 26.

The so far based on the Pig. 1 described

Apparatus for producing an air-laid paserbahn can also be used by known others serving the same purpose Facilities to be replaced. The one in Pig. 1 selected pre

509807/0598

direction, however, has the advantage that it is the production a fiber web 10 which is particularly suitable for the purposes of the invention, especially at high operating speeds. The shaft shown in Fig. 1 has a width about the height of the plucking teeth on the plucking roller 22 corresponds, and the arrangement of this conveyor shaft is made so that the fibers flying off the plucking roller 22 enter the conveying shaft in the tangential direction " can. These measures make it possible to control the speed of the fibers 14 over the length of the conveyor shaft 24 in a practical manner to keep constant, and this contributes to the fact that the fiber web 10 produced in the manner shown in FIG has an extremely good uniformity and is practical is completely free of fiber flakes or similar agglomerations.

The weight of the airlaid fibrous web 12 depends on the intended use of the end product. Usually the track weight is in the range of

Order of about 8-85 g / m, with sheet weights of about

17-43 g / m are the preferred range. The type of cellulose fibers used to produce the fiber web 10 is not critical, it depends somewhat on the desired surface texture of the end product. For example Cedar fibers lead to a fibrous web with a soft, fluffy texture, while a slightly more woolly texture with reinforced Body made from fibers of the "Southern Pine" can be obtained.

509807/0598

After the formation of the fiber web 10 on

the wire screen 26 the free upper surface of the fiber web is brought into contact with a heated take-off roller 32, which are at some distance in the running direction of the wire screen behind the device part for producing the Paserbahn is located. This take-off roller 32 rotates at a speed that essentially corresponds to the running speed of the wire screen 26 Peripheral speed and takes the fiber web from the wire ie b 26. TJm to promote the decrease can thereby the sieve 26 may be wrapped around the roller 32 to a small extent.

The surface of the pickup roller 32 is

with numerous small, more or less punctiform elevations on which an adhesive is continuously applied. The adhesive is located in a reservoir 36 and is applied by means of a set of transfer rollers 38,40 applied to the elevations on the surface via take-off roller 32. The elevation on the. Roller 32 is relatively steep, its height can be in the range of about 0.3-0.8 mm.

The one on the bumps on the roller

Applied adhesive is in a form of a solvent or dispersant acting liquid distributed. When the fiber web 10 comes into contact with the roller 32, this liquid penetrates and thus also the adhesive distributed therein quickly into the fiber web, whereby the air-laid fibers in those

509807/0598

Areas that affect the distribution of the bumps on the surface the roller 32 correspond to be moistened. This rapid moistening leads to a preliminary connection of the fibers of the fiber web, so that the fiber web passes from the wire onto the surface of the roller 32 without any significant disturbance of its structure can be transferred.

After being transferred to roller 32

the fiber web 10 remains on the heated surface for so long the roller 32 until the liquid contained in the adhesive has evaporated, the adhesive solidifying in the process remains behind. This leads to the desired "bound" Fiber web that forms the end product. This bound fiber web is rolled from the take-off roller 32 via a further roller 42 accepted and sent for further processing. The decrease of the end product from the roller 32 can be conveyed in that the surface of the roller 32 is coated with an adhesive, thus made of a "repellent" material such as tetrafluoroethylene is. Incidentally, in the same way, the transfer of the fiber web 10 from the wire screen 26 to the take-off roller 32 to favor the wire screen 10 coated with an adhesive material or made entirely of such a material be made.

For the purposes of the invention, it is important that the liquid containing the adhesive in the form of many discrete, that is, unrelated stains are applied to the surface of the roller 32. The distance

509807/0598

this spot should be less than the average length of the strands contained in the fibrous web. Such a distribution pattern for the liquid not only ensures that the fibrous web maintains adequate cohesion as it is transferred from wire screen 26 to roller 32, but also ensures that the final product bonded by the adhesive becomes fully adequate for most uses . The distribution pattern of the liquid in the fiber web (which corresponds to the distribution pattern of the elevations on the surface of the roller) is expediently designed so that in the end product in both surface dimensions bound areas with a frequency of about 10 to 40 bonds per surface of 6.45 cm (one square inch) and that the bonded areas total about 10 to 40 percent of the total area of the web. Sheets bound in this way not only have sufficient strength, but are also characterized by a very good absorption capacity and a very pleasant feel. This is primarily because there are substantial areas of unbonded fibers between the bonded zones of the web.

Furthermore, it is also important for the invention that the fiber web practically without disturbing its original air-laid structure is transferred to the take-off roller 32 and that it does not compress significantly will. Using an essentially uncompressed air-laid fiber web favors the rapid penetration of the liquid with the adhesive at the moment of contact

5 09807/0598

-H-

Fiber web with the surface of roller 32. As a result, the fiber web is initially only provisional, but instead practically immediate initial strength granted that the

promotes structural cohesion of the railway.

The type of adhesive used does not matter, as long as it is ensured that the adhesive is used can be used in combination with a liquid which penetrates rapidly into the fiber web and that the When set, the adhesive has sufficient strength and does not remain noticeably sticky.

There are many types of adhesives on the market,

which can be dispersed in a liquid medium and at a temperature that is necessary for the liquid to evaporate necessary temperature is the same or can be lower, change into a solid, non-sticky state, to disposal. Many of these types of adhesive can be used as Use aqueous solutions or aqueous dispersions. Examples include numerous starches, water-soluble polymers Materials and water-dispersible resins such as vinyl resins (e.g. polyvinyl acetate and vinyl acetate-ethylene copolymers) as well as acrylic resins. Adhesive materials can also be used how vinyl resins are applied in the form of a solution in suitable organic solvents. Also is it is possible to use plastisols of sufficiently low viscosity, for example polymeric materials such as vinyl polymers (e.g. polyvinyl chloride) and copolymers used in

509807/0598

liquid plasticizers such as dioctyl phthalate and the like are dispersed. With these plastics, the removal of the liquid component, namely the plasticizer, is effected by that the plasticizer in the "when hardening the plastisol resulting polymeric particles is absorbed.

The one in Pig. 1 is based on the use of an adhesive belonging to the aforementioned types. Alternatively, however, meltable adhesives in the molten state can also be used. These adhesives unite the puncture of the liquid and the adhesive puncture in a substance, in that when the melt cools, the liquid character disappears and the solidified adhesive remains. The device according to Pig. 1 must then be modified to the effect that the molten Cool the adhesive sufficiently on the surface of the roller 32 or, at the latest, on the upper surface of the roller 42 can.

Pig. 2 schematically illustrates, in cross section, one with the device according to Pig. 1 produced "bound paserbahn". This path is characterized by a continuum of fibers 44, which is formed by a pattern of adhesive bonds 46 is interrupted. In the area of adhesive bonds are those Pipes are highly compressed compared to the unbonded areas between the bonds. It can be seen as typical be that the strength of the unbound areas is at least several times greater than the strength of the bound Areas.

In Pig. 3 is schematically a further embodiment of a device for carrying out the

509807/0598

represents inventive method. In the device according to Pig. 3, an airlaid fibrous web 48 is formed on a rotating wire screen 50, preferably in the same manner as this with reference to Pig. 1 has already been described. This fiber web is transported with the wire 50 to the gap between a wire deflection roller 52 and a heated take-off roller 54. The surface of the take-off roller 54, like the surface of the take-off roller 32, carries in Pig. 1 an adhesive liquid that is distributed on the roller surface in small, discrete spots with a predetermined distribution pattern. In contrast to the roller 32, however, the surface of the take-off roller 54 is smooth, and the adhesive is applied to the surface of the roller 54 with an intaglio roller 56 in the manner of the offset process. The intaglio roller 56 is located above the take-off roller 54 and has a rubber surface in which small depressions are formed in a distribution pattern which corresponds to the desired distribution pattern of the adhesive on the surface of the take-off roller 54. These depressions in the surface of the intaglio roller 56 are filled with the adhesive liquid, and since the intaglio roller 56 is in slight pressure contact with the pick-up roller 54, the adhesive is transferred from the depressions of the intaglio roller to the surface of the pick-up roller . To fill the depressions in the intaglio roller, a supply of adhesive liquid can be used, which is located in a space delimited by the intaglio roller 56 on the one hand and a scraper blade 60 on the other and, for example, from a storage container 58 via a pump P is constantly kept at a constant level. When rotating

509807/0598

of the intaglio roller 56 fill the surface arranged wells with the adhesive liquid, while the adhesive liquid from the non-recessed Areas of the surface of the intaglio roller 56 is stripped by the doctor blade 60, so that at the moment of The intaglio roller 56 contacts the take-off roller 54 the non-recessed areas of the intaglio roller are adhesive-free are.

When the parts of the surface covered in such a way with the discrete stains of the adhesive liquid the take-off roller 54 in the gap between the rollers 54 and 52 come into contact with the fibrous web 48, the penetrates. Adhesive liquid as well as in the device according to Fig. 1 quickly into the fiber web, with an immediate, provisional solidification effect, just as in the device according to FIG. 1 ″ entry. There is also the one with the adhesive liquid wetted surface of the take-off roller 54 for the fiber web 48 is "more attractive" than the wire screen 50, is in the gap between the rollers 54 and 42, the fiber web 48 is transferred to the surface of the removal roller 54, namely in practically intact condition. In order to ensure this transfer properly, it is useful to adjust the gap width of the gap between the rollers 54 and 52 to be set small enough so that the fiber web 48 can come into contact with the surface of the take-off roller 54, but with the gap width should not be so small that the ones on the surface

509807/0598

the take-off roller 54 ″ located through the adhesive liquid the Faserbabji 48 can pass through onto the wire 50. This is because if the surface of the wire ie be s 50 is also contaminated with adhesive liquid in the course of operation is, the screen 50 also develops some adhesiveness for the fiber web, through which the transfer of the fiber web to the take-off roller 54 can be impaired.

The further treatment of the fiber web in the device according to FIG. 3 corresponds to that already based on the treatment explained in FIG. 1. The fiber web remains in contact with the take-off roller 54 until the liquid in the adhesive liquid is removed and the adhesive becomes has solidified. Thereafter, the "bonded fiber web" is removed from the take-off roller 54 via a roller 62 and the further processing. Has preferential prices to promote the transfer of the "bonded fiber web" to the roller 62, the removal roller 54 has an adhesive surface, as has already been mentioned with reference to FIG. Alternatively, however, if the roller 54 has a smooth steel surface possesses, from which the fiber web cannot be removed very easily, the transfer of the "bound fiber web" on the roller 62 with the aid of a conventional take-off blade.

The embodiment shown in FIG to carry out the method according to the invention is the Embodiment according to FIG. 3 is very similar, but differs from this in that instead of the take-off roller 54 a

509807/0598

A decrease element in the form of an endless belt 70 is used will. The air-laid paserbane 66, which in turn is expediently produced in the manner explained in FIG. 1, and itself is located on a rotating wire screen 64, is in one between the wire screen 64 and the endless take-off belt 70 The gap 68 formed by two rollers is transferred from the wire screen to the removal belt 70. The acceptance tape 70 is in a station 72, which is an intaglio roller 56 ', a Reservoir 58 ', a pump P and a doctor blade 60' and which is similar to the corresponding part of the device in FIG. 3, with small, discretely distributed spots an adhesive liquid, the distribution pattern of these spots being the distribution pattern of the depressions corresponds in the surface of the intaglio roller 56 '.

The fiber web transferred to the removal belt 70 in the removal gap 68 is, as in the examples explained above, immediately penetrated by the adhesive liquid and thus temporarily solidified. The final solidification takes place by removing, for example, evaporation of the liquid, whereby the adhesive solidifies. However, since it is difficult to keep the removal tape 70 from the removal gap 68 in a heated state, as is necessary for the removal of the liquid and the solidification of the adhesive, it is expedient to keep the fiber web temporarily solidified in the removal gap 68 at a distance behind the removal gap 68 again from the removal belt 70 and transferred to a heated roller 74, on which then

509807/0598

the liquid is removed and the adhesive finally solidifies will. In order to promote this transfer of the fiber web to the roller 74, it is as in those explained above Examples expediently to coat the surface of the removal tape 70 abhesively. Besides, it's the same Purpose favorable, the peripheral speed of the roller 74 slightly set higher than the running speed of the Belt 70. Since the fiber web 66 in the contact point of the roller 74 temporarily stabilized with the band 70 iat, impaired the tension necessary to transfer the fiber web to the roller 74 does not affect the cohesion of the fiber web.

After the final solidification of the

The glue and the removal of the liquid is the end product, the “bound fiber web”, done, this is then removed from the roller 74. A crepe blade can be used for this can be used, but it can also be used in the already in the manner explained with reference to Fig. 3, i. the removal can take place by means of a further roller, in which case the surface of the roller is again expedient 74 is coated with an adhesive, or the entire roller 74 is made of an adhesive material.

The device shown in Fig. 4 is

especially useful when the glue fluid is in shape an adhesive melt is used. In that case the Adhesive in station 72 in a molten state is applied to the decrease tape 70, and also the Roller 74 operated as a cooling roller. At the latest on the upper

509807/0598

The molten liquid goes flat on the cooling roller 74 Glue in its solid state.

Look the Pig. 2 it was explained that

the end product has areas of unbound fiber, as well as others distributed in a certain distribution pattern Areas in which the fibers are connected by glue. If as acceptance elements for the acceptance of the Paserb ahn of the Wire screen a pick-up roller in the style of Pig. 1 used with raised elevations coated with the adhesive liquid is, the bonded areas of the tape are compressed, so that the strength of the bonded areas around becomes many times less than the strength of the unbound areas. The same character of the Paserbahn can but can also be achieved by other means, for example by applying a low pressure when transferring the fiber web from the screen to a smooth removal element. By Such a slight pressure compresses the fiber web over its entire surface when the pressure is released however, the areas not penetrated by the adhesive liquid spring back elastically to their original position State back while the areas penetrated by the adhesive fluid remain compressed. Will continue the same character is also achieved with the "bonded paserbahn" when the liquid in which the adhesive is distributed is, has the ability to expand the pasers of the paserbahn. In the case of wood fibers, this particularly applies to water the removal of the water occurring on the surface

509807/0598

Forces decreasing tension compress the fiber web in the moistened areas, so that in this case too "bound, fibrous web" arises at which the strength of the bound Areas is much less than the strength of the unbound areas.

-Pattern claims-

CFU / kä

509807/0598

Claims (7)

Claims 1 J Iiuftgelegte fiber web with a low web weight and in particular of cellulose fibers for use in disposable wipes or the like, characterized in that a three-dimensional Kontiuum of fibers is provided in the air-laid state gekennzeichne1 _1, which is interrupted by individual discrete, distributed in a predetermined distribution pattern bonded adhesive areas, wherein the adhesive-bonded areas are compared to the unbonded regions to a thickness which is many times less than the thickness of the unbonded areas, compressed and their distance from one another is less than the average length of the fibers, and wherein the adhesive is supplied from the outside and is limited to the adhesive-bonded areas. 2. A method for producing a fiber web according to claim 1, characterized in that it is assumed from a circulating open-pored wire screen dry air laid track of non-compressed, statistically oriented fibers that this track on the remote side of the wire screen with a decrease E le me nt is brought into contact, which revolves at approximately the same speed as the wire screen and carries on its surface in a distribution pattern which corresponds to the distribution pattern of the adhesive-bonded areas in the end product, an adhesive plush, which at the moment of contact of the 509807/0598 Remove element with the Paserbahn quickly in this across Level penetrates, and that then the adhesive is solidified. 3. The method according to claim 2, characterized in that the adhesive liquid is a mixture of an adhesive and a liquid acting as a solvent, dispersant or plasticizer, and that the solidification of the adhesive occurs with simultaneous removal of the liquid by heating the removal element . 4. The method according to claim 2, characterized in that the adhesive liquid is a molten adhesive and that the solidification of the adhesive occurs by cooling the decrease-E le me nt s. 5. The method naoh one of claims 2 to 4, characterized in that the adhesive-bonded areas are compressed by raised projections coated with the adhesive liquid on the removal element. 6. The method according to any one of claims 2 to 4, characterized in that the adhesive-bonded areas are compressed in that the fiber web is compressed as a whole when removed from the wire screen and that after pressure relief only the areas not penetrated by the adhesive liquid are elastic jump back to about their original layer thickness. 509807 / Q598 7. The method according to any one of claims 2 to 4, characterized gekennzelehnet that the adhesive-bonded areas are compressed by using a fiber-softening liquid, preferably water, as a component of the adhesive liquid by removing the liquid
the areas of the fiber web penetrated by it are compressed by forces due to the surface tension. KRE / kä 509807/0598 Blank page