CA2022080C - Low fluid pressure dual-sided fiber entanglement method, apparatus and resulting product - Google Patents
Low fluid pressure dual-sided fiber entanglement method, apparatus and resulting productInfo
- Publication number
- CA2022080C CA2022080C CA002022080A CA2022080A CA2022080C CA 2022080 C CA2022080 C CA 2022080C CA 002022080 A CA002022080 A CA 002022080A CA 2022080 A CA2022080 A CA 2022080A CA 2022080 C CA2022080 C CA 2022080C
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- Prior art keywords
- fluid
- starting material
- streams
- fiber
- nonwoven fabric
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Classifications
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H18/00—Needling machines
- D04H18/04—Needling machines with water jets
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
- D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
- D04H1/58—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives
- D04H1/64—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives the bonding agent being applied in wet state, e.g. chemical agents in dispersions or solutions
- D04H1/655—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives the bonding agent being applied in wet state, e.g. chemical agents in dispersions or solutions characterised by the apparatus for applying bonding agents
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- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Dispersion Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Nonwoven Fabrics (AREA)
Abstract
A low fluid pressure dual-sided fiber entangling method and apparatus for manufacturing a nonwoven fabric.
A fibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces is subjected to coacting opposed fluid streams while being confined between a flexible screen belt and a rigid perforated hollow drum.
The fibers of the starting material are entangled under the effect of fluid forces applied in opposition, forming a reticular network which defines a pattern of blind holes, each hole extending transversely to the fabric plane and containing a protuberant fiber packing at a closed end thereof.
A fibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces is subjected to coacting opposed fluid streams while being confined between a flexible screen belt and a rigid perforated hollow drum.
The fibers of the starting material are entangled under the effect of fluid forces applied in opposition, forming a reticular network which defines a pattern of blind holes, each hole extending transversely to the fabric plane and containing a protuberant fiber packing at a closed end thereof.
Description
- 1 202208~
TITLE: LOW FLUID PRES5URE DUAL-SIDED FIBER EN--TAN-GLEMENT
HETHOD, APPARATUS AND RESULTING PRODUCT
FIELD OF THE INVENTION
The invention relates to the general field of fibrous materials and, more particularly, to a novel method for entangling loosely associated fibers to form a unitary reticular network by using fluld streams applied in opposition to the fibers. The invention also extends to an apparatus for carrying out the method and to the resulting product.
BACKGROUND OF THE LNV~;~TlON
Nonwoven fabric3 are well-~uited for applications which require a low cost fibroul3 web. Example~ are disposable artlcles such as polishing or washing cloth3, cast paddings and facing layer3 for fibrous mat products.
Nonwoven fabrics are normally produced from a web of loosely associated fibers that are subjected to a fiber rearranging method to entangle and mechanically interlock the fiber3 lnto a unitary reticular network. The fiber rearrangement i3 achieved under the effect of fluid force~
applied to the fibers through a fluid ~ermeable web - 2 ~ 2022080 confinlng and supparting structure comprising a rigid apertured member with a predetermlned pattern of fluld passages, and a flexible foraminous sheet disposed in a face-to-face relationship to the apertured member. In one form of construction, the rigid apertured member iB a rotating hollow drum and the flexible foraminous sheet is an endless screen belt in overlapping relationship with the hollow drum and advancing therewith. The web of loosely associated fibers which forms the starting material of the nonwoven fabric production method is confined between the drum and the screen belt and i~
advanced through a fluid stream creating the entangling forces on the fibers.
~he so-called "Rosebud" nonwoven fabric production method reguires that the fluid stream be located outside the hollow drum, the fluid partlcles impinging on the fibers through the screen belt. In operation, the fibers are drawn by the fluid mass flowing out of the apertured hollow drum, into the fluid passages thereof, and they are mechanically interlocked and entangled in protuberant packings which are interconnected by flat fiber bundles extending over the land areas of the drum. The resulting nonwoven fabric has a three-dimensional structure presenting a knobby side containing the apexes of the fiber packings, and a ~lat and smoother side containing _ 3 _ 2022080 the base portions of the fiber packings and the interconnecting bundles.
In a variant of the Rosebud method, known as the "Keybak" method, the direction of the fluid stream i3 reversed, whereby the fluid particles reach the fibers by passing through the fluid passages on the drum. In contrast to the Rosebud method, the fibers are packed together on the land areas of the drum forming a network with clear holes arranged into a pattern corresponding to the pattern of fluid passa~es on the hollow drum.
For a wide range of applications, nonwoven fabrics having superior resistance characteristics are required.
Basically, the resistance or durability of a nonwoven fibrous web depends on the degree of fiber entanglement achieved during the fiber rearranging process. When the fibers are tightly interlocked, they form a den~e and tenacious network which is highly resistant to forces tending to destroy the web integrity, such as tear ~orces for example. In contrast, a web constituted by loo~ely associated fibers is substantially less resistant because, at the ~iber Level, the network of the web lacks cohesion.
_ 4 _ 2 02208~
In conventional nonwoven fabric production methods, a certain increa8e in the degree of fiber entanglement may be achieved at the fiber rearranging stage by increasing the fluid supply pressure of the stream in order to augment the intensity of the fluid forces acting on the fibers. However, there are disadvantages and inherent limits in increasing the fluid supply pressure which considerably offset any advantage that may be gained in terms of higher fiber entanglement. Traditional production methods already require fairly high fluid supply pressures and a further pressure increase creates considerable strain on the equipment whlch translates lnto an increa3e of the fabric manufacturing cost. In addition, regardles3 of cost con6ideratlons, the fluid supply pre3sure cannot be indefinitely increased a3 beyond a certaln polnt, a destructive condition known as "floodlng" occurs which is deflned as a loss of web ldentity resulting from the appllcatlon of fluid forces to the fiber which are too intense.
It is also known from the prior art to apply a binder substance to the fiber3 of the fabric subsequently to the fiber rearranging step, in order ~o increase the fabrlc resistance. The binder substance, when cured, establishe3 a bond ~etween ad~acent fiber3 and prevents them to move one relative to the other. Accordingly, the tenacity of - S- 202208~
the fabric will increase because of the reduction in the inter-flber displacement when destructive forces act on the fabric.
Although a binder can effectively increase the resistance of a nonwoven fabric, for cost considerations, it cannot be considered as an ideal solution.
Fundamentally, the ob~ective of any nonwoven fabric production method is to turn out the least expensive product, therefore, it is desirable to eliminate or at least reduce as much as possible the binder application.
OBJECTS AN-D STATEMENT OF THE LNv~b~
An object of the invention is a novel three-dimensional nonwoven fabric having superior resistance characteristics and possessing two textured sides, high bulk, softness, better absorbency and aesthetics.
Another ob~ect of the invention is a novel low pressure fluid formation method and apparatus for producing the aforementioned fabric.
Yet, another object of the invention is a method and an apparatus for fluid formation of nonwoven fabrics allowing a higher level of control of the fabric structure .
s In one aspect, the invention provides a method for fluid formation of a unitary nonwoven fabric, comprising the steps of:
- providlng a fibrous ætarting material whose lndividual fibers are capable of movement relatively to one another under the lnfluence of applied fluid force8;
and - sub~ecting the fibrous starting material to opposed coacting fluid stre~ms while supporting the material between an apertured member having a predetermined pattern of fluld pas~ages therethrough and a foraminous fluid permeable member, whereby under the influence of fluid forces applled ln opposltion, the individual fiberæ of the starting materlal are entangled forming a reticular network which defines a pattern of holes corresponding to the predetermined pattern of fluid passages on the apertured member.
- 7 ~ 2022080 For the purpose of this speclfication, the scope of the expression "opposed coacting fluid streams" is not intended to be restricted to an arrangement where the fluid streams are colinear, but should be con5trued to encompass any form of construction where a given fiber of the starting material is sub~ected simultaneously ~o the influen~e of fluid streams having generally opposite directions. Having regard to the foregoing, an embodiment with slightly offset or staggered fluid streams is considered to meet this definition at the condition that the ma~ority of the fibers in the web of starting material are long enough and are oriented in such a way as to span the offset between the streams. Hence, a given fiber under fluid treatment will be affected simultaneously by the streams, albeit the streams will be acting on different portions of the fiber. The degree of offset between the streams which will determine whether they are coacting or not is primarily a function of fiber length and fiber orientation. In a web formed of short fibers, only a small offset will be allowed, however in a web of longer fibers, it is possible to further space the streams and still retain the benef it of a simultaneous dual stream action on the fibers.
In addition, the respective propagation paths o~ the streams do not necessarily have to be parallel or colinear in order to be characterized by "opposite". This word is to be interpreted ln a broad sense/ as it ls intended to encompass embodiments where the streams are at a certain angular relationship which is such that the streams give rise to fluid forces whose principal components are applied to the web along truly opposite directions.
In a preferred embodimentr the apertured member is a rotating rigid hollow drum while the foraminous ~luid permeable member is an endless screen belt for holding the fibrous starting materLal agalnst the drum. The opposed fluid streams are created by providing inslde and outside of the hollow drum, manifolds with respective ~ets disposed in a face-to-face relatlonship. The fluid mass coming from the manifold positioned outside the hollow drum is diffused through the screen belt and impacts on the fibers drawing them in the fluid passages of the drum as this fluid mass flows therethrough. The opposite ~luid stream produced by the inside manifold passes through the fluid passages and has a tendency to e~ect the fibers out of the fluid passages and to pack them over the land areas of the hollow drum. Surprisingly, it has been found that the fluid forces applied to the fibers in opposition have a synergistic effect, rearranging the fibers into a - 9 - 2~22080 retlcular network having a substantially higher degree of entanglement and cohesion comparatively to what can be achieved with a single-sided fluid formation method, be it the Rosebud or the Beybak method.
The method according to the invention is hi~hly advantageous because it uses a relatively low fluid supply pressurer yet it can deliver a higher fiber entanglement comparatively to single sided fluid formation methods, to produce fabrics which require less binder to achieve predetermined resistance characteristlcs. In addltlon, the method can also increase the fabric performance in bulk, softness, absorbency and texture.
The dual-sided fluid entangling method can achieve dlfferent fabrlc structures by selectively varying the intenslty of the fluld forces actlng in opposition on the fibers. In one extreme condition when only the manifold located lnslde the hollow drum operates, the nonwoven fabric has a network definlng a pattern of clear holes corresponding to the pattern of fluld pa~sages on the hollow drum. Thls fabrlc structure 18 ldentlcal to what can be obtained with the Keybak method.
By actlvatlng the outside manlfold to lmpinge a fluid stream on the flbrous startlng material through the screen belt, the structure of the nonwoven fabric is altered.
The clear holes wlll start closing at the extremity facing the screen belt and a protuberant fiber packing will form at the closed end of each hole. Thls three-dimensional fabric structure i8 novel and constitutes another aspect of the present invention. Conventional three-dimensional fabrics have only one textured side, the other one being flat, while the aforementioned network structure provides a fabric with two textured surfaces having a very distinct appearance and feel. On one side of the fabric are disposed the openings of the blind holes creating a pattern of recesses, the opposite side being knobby as a result of the protuberant f iber packings closing the holes .
Eurther augmenting the velocity of the stream from the outside manifold with respect to the velocity of the stream from the inside manifold will result in a further growth of the fiber packings at the expense of an erosion of the network defining the holes which will become shallower, bringing the fiber packings closer to the drum surf ace .
Shutting down the inside manifold is the other extreme condition. The fiber packings will grow larger and will penetrate into the drum openings. The holes will - 11 - 202208~
disappear creating flat fiber bundles interconnecting the protuberant fiber packings and extending over the land areas of the drum. This fiber structure is eguivalent to what is achieved wlth the Rosebud method.
In summary, each fluid stream imparts a distinct pattern to the web of starting material and when the opposite streams are simultaneously applied to the web, the fibers are tightly entangled into a fabric network where the two patterns coexist. If it is desired that one of the patterns predominates the other, this can be achieved simply by increasing the intensity of the fluid stream creating this pattern relatively to the intensity of the other stream.
The ability of the method to control the fabric structure constitutes another aspect of the invention. In broad terms the method can be expressed as the combination of the following steps:
- providing a fibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces - ~ub~ecting the fibrous starting material to coacting opposed fluid streams while confining the material between spaced apart foraminous members forming a fluid permeable supporting structure, whereby under the - 12- 2~22080 influence of fluid force3 applied in opposition the individual fibers of the material are entangled forming a reticular network; and - controlling the intensity of the fluid forces to control the fiber distribution profile of the network in a trensverse direction to the plane of the nonwoven fabric .
In a further aspect, the invention provides an apparatus for producing a unitary nonwoven fabric from a fibrous 6tarting material whose individual fibers are capable of movement under the influence of applied fluid forces, the apparatus comprising a fiber rearranging station which includes s a) an apertured member having fluid passages therethrough;
b) a foraminous member spaced apart from the apertured member to define therewith a fluid permeable supporting structure for the fibrous starting material;
2 0 and c ) means to generate opposed and coacting f luid streams producing respective fluid forces which are applied in opposition to the starting material through the fluid permeable supporting structure, causing a dual-sided fiber entangling of the starting material to form the nonwoven fabric.
- 13 ~ 2~22080 AdvantageoUsly, the apparatus comprises means to control the intensity of the fluid forces in order to control the nonwoven fabric structure. In a preferred embodiment, the pressure of the fluid supply to the jets producing the streams can be selectively varied to produce the desired fabric network pattern.
As embodied and broadly described herein, the invention provides a method for fluid formation of a unitary nonwoven fabric, comprising the steps of:
- providing a f ibrous starting material whose individual f ibers are capable of movement relatively to one another under the influence of applied fluid forces;
and - subjecting said fibrous starting material to coacting first and second opposed fluid streams while supporting the material between an apertured member having a predetPrm~nPd pattern of fluid passages therethrough and a foraminous fluid permeable member, said first fluid stream acting through said apertured member so as to tend to f orm a pattern of holes in said f ibrous starting material corresponding to said predetermined pattern of fluid passages, said second fluid stream acting through said foraminous member, the force of said second fluid stream relative to said f irst f luid stream being maintained so that said second fluid stream tends to close ...
i,`;
- 13a - 2n22080 t said holes formed by said first fluid stream by packing a portion of said f iber6 into said holes, whereby under the influence of fluid forces applied in opposition, the individual fibers of the material are entangled forming a retioular network of holes at least partially closed by said f iber packings .
As embodied and broadly described herein, the invention also provides a method for fluid formation of a unitary nonwoven fabric, comprising the steps of:
- providing a f ibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces;
- subjecting said fibrous starting material to coacting first and second opposed fluid streams while supporting the material between an apertured member having a predetermined pattern of fluid passages therethrough, and a foraminous fluid permeable member, said first fluid stream acting through said apeL l_UL ~d member so as to tend to form a pattern of holes in said ~ibrous starting material corresponding to said predet~r~ninc~ pattern of fluid passages, said second fluid stream acting through said foraminous member, the force o~ said second fluid stream relative to said first fluid stream being maintained so that said second fluid stream tends to close said holes formed by said first fluid stream by packing a portion of said fibers into said holes, whereby under the - 13b - 2~22080 influence of fluid forces applied in opposition, the individual fibers of the material are entangled forming a reticular network of holes in which f iber packings are formed; and - controlling the intensity of the fluid forces to control the degree to which said fiber packings close said holes .
As embodied and broadly described herein, the invention further provides a method for fluid formation of a unitary nonwoven fabric, comprising the steps of:
- providing a f ibrous starting material whose individual fibers are capable of movement under the influence of applied fluid forces;
- conf ining said f ibrous starting material between first and second fluid permeable members forming a supporting structure, said first member having a plurality of apertures forming a pattern;
- passing said fibrous starting material confined between said f irst and second members through a f luid treatment station comprising opposed f irst and second coacting f luid streams in a staggered relationship producing respective fluid forces which are applied in opposition through said supporting structure, said first fluid stream acting through said apertured member, therQby tending to form a pattern of holes corresponding to said pattern of apertures, said second fluid stream applied in , = .
- 13c ~ 2022D80 opposition to 5aid first fluid stream, thereby tending to close said holes formed by 6aid first fluid stream by packing a portion of said fiber5 into said holes, whereby a progressive dual-sided fiber entangling of said f ibrous starting material occurs 50 as to form the nonwoven fabric having a f irst side in which a pattern of holes are disposed and a second side in which a protuberant f iber packing closes each of said holes.
As embodied and broadly described herein, the invention further provides a method for fluid formation of a tri-dimensional unitary nonwoven fabric, comprising the steps of:
- providing a f ibrous starting material whose individual f ibers are capable of movement relatively to one another under the influence of applied fluid forces;
- subjecting said fibrous starting material to a plurality of coacting first and second opposed fluid streams while confining the material between spaced apart f luid permeable members, whereby under the inf luence of fluid forces applied in opposition the individual fibers of the material are entangled forming a reticular network defining a prede~orm~ d pattern of holes formed by said first fluid stream, each hole extending transversely to the plane of the fabric and containing a protuberant fiber packing formed by said second 5tream and clo5ing said holes, and - 13d - 2022080 - controlling the relative intensity of said ~luid forces of said first and second ~luid streams to control the f iber distribution provide of said network in a transverse direction to the plane of the nonwoven fabric.
BRIBF DE~r~TPTION OP T~IB DRAWING5 - Figure 1 is a schematical view of the fiber rearranging station of an apparatus for producing a nonwoven fabric in accordance with the invention;
- Figure 2 is an enlarged fragmentary side view of the fiber rearranging station, illustrating the manifolds creating the opposed fluid streams;
- Figure 3 is a perspective and ~ further enlarged view of the f iber rearranging station illustrating in addition to Figure 2, the structure of the perforated hollow drum and of the screen belt for holding and advancing fibrous starting material between the fluid str~ams;
- Figure 4 i8 a graph showing the effect of manifold pressure on the tenacity of the nonwoven fabric;
- Figures 5, 6, 7, 8 and 9 are schematical diagrams illustrating how the variation of the intensity of one fluid stream relative to the other fluid steam affects the fiber rearranging process;
- Figure 10 i8 a photomicrograph of a nonwoven fabric produced with the apparatus depicted in Figure~ 1, 2 and 3r showing the side of the fabric which faces the perforated hollow drum;
- Figure 11 is a photomicrograph of a nonwoven fabric produced with the apparatus depicted in Figures 1, 2 and 3~ showlng the slde o~ the fabrlc facing the screen belt;
and - Figure 12 is a schematical view in cross-section of the fabrlc shown in Figures 10 and 11; and Throughout the drawin~s, the same re~erence numerals designate identi~al or similar components.
.
- 15 ~ 202~080 DESCRIPTION OF A ~t;r~;n~rll E~IBODIHENT _ Flgure 1 i5 a schematlcal side view of the fiber rearranglng station of an apparatus used for the manufacture of a nonwoven fabric by applying fluid forces to a web of starting material in which the individual fibers are loosely associated and are free to move one relatively to the other. The fiber rearranging station, identified comprehensively by the reference numeral 10, comprises a hollow metallic drum 12 mounted for rotation about its longitudinal axis into a suitable cradle ~ not shown). A drive mechanism (not shown) is provided to rotate the drum 12 in the counterclockwise direction, as shown by the arrows 14 at a controlled speed. The drive mechanism i8 of a well-known construction and does not form part of thls lnventlon.
The structure of the hollow drum 12 wlll be described with more detail by referring to Figures 2 and 3. The shell of the drum 12 is provided on its entire surface with perforations 16 arranged into a predetermined pattern and separated from one another by land areas 18 corresponding to the closed or impermeable zones of the drum 12. The pattern of the openings 16 is an important factor which determines, in conjunction with other factors, the network structure o~ the nonwoven fabric. In - 16 ~ 2022080 the art of manufacturing nonwoven fabrics, the effect of the perforation scheme on the nonwoven fabrlc structure is well understood by those skilled in the art and it is not deemed necessary here to discuss this matter.
Referring back to Figure 1, the fiber rearranging station 10 also comprises an endless screen belt 20 which is mounted in a partially overlapping relationship to the drum 12 by means of guide rollers 22. Support rollers 24 are positioned at the corners of an imaginary rectangle and act, in con~unction with guide rollers 22, to tension and establish a path for the ~creen belt 20. One or more of the rollers 22 or 24 are drive rollers for advancing the belt 20 in unison with the drum 12, in other words to prevent a relative translatory motion therebetween.
The structure of the screen belt 20 is another factor influencing the network structure of the nonwoven fabric, as it is known to those skilled in the art. Therefore, the screen belt must be selected carefully in accordance with all the other operating conditions o~ the machine, such as the type of drum which is being used, the type of fibers to be processed and the desired fabric network structure and surface finish, amon~ others, to optimize the performance of the machine.
- 17 ~ 2~22080 A pair of manlfolds 26 and 28 are mounted on either slde of the structure formed by the screen belt 20 and the hollow perforated drum 12 to create fluid streams for rearranging loosely associated fibers confined between the drum 12 and the screen belt 20 into a unitary, thin reticular network. The manifold 26 is located outside the hollow drum 12 and includes a metallic box 30 with a concave wall 32 which faces the drum/screen belt and has a curvature corresponding to the curvature of the drum shell. On the concave wall 32 are mounted a series of water jets or nozzles 34 in fluid communication with the interior of the box 30 so as to create a plurality of fluid streams impinging on the screen belt 20. The concave shape of the wall 32 permits the orientation of each jet 34 into a radial direction relative to the drum/
screen belt and also to position the extremity of each nozzle at exactly the same d$stance from the screen belt 20. This feature is best illustrated in Figures 1 and 2.
The nozzles 34 are grouped into four parallel rows, each row extending along the longitudinal axis of the drum 12. The nozzles produce fluid streams under the form of flat cones lying in an imaginary plane which contains the drum longitudinal axis, the nozzles into the same row being spaced from one another by a distance 50 that a certain overlap occurs between streams from ad~acent - 18- 2~22080 nozzles immediately in front of the screen belt 20. The distance between successive nozzle rows is relatively small so that, for all practical purposes, the individual fluid streams produced by the nozzles 34 are united into a common fluid front acting on a given area of the fibrous web ln the drum~screen belt facing the manlfold 26.
The structure of the manifold 28 is essentially the same as in the case of the manifold 26, the only exception being that the front wall of the manifold is convex rather than concave for following the internal curvature of the hollow drum 12, and also six rows of nozzles are provided instead of four.
The individual fluid streams from one manifold do not necessarily have to be colinear with the indlvidual fluid streams from the other manlfold. A certain degree of offset or stagger, elther ln the machine dlrection, the cross-machine directlon or an intermediate direction, is aLlowed upon the conditlon that the majority of the fibers forming the starting material are long enough and oriented in such a way as to span the offset dlstance between two opposite fluld streams, whereby the fibers will be sub~ected to the influence of fluid forces applied in opposition, albeit acting on different portions of a given fiber. The maximum permissible amount of offset depends upon the average f lber length . The orientation of the offset should normally be consistant with the fiber orientation ln the starting material.
The embodiment shown in Figure 2 is an exemplary hybrid form of construction where the two lower nozzle rows of the manifold 26 are perfectly in line with the two lower nozzle rows of the manifold 28, while the two upper nozzle rows of manifold 26 are slightly offset with relation to their companion nozzle rows of manifold 28.
The important point is that the arrangement does not adversely affect the operation o~ the apparatus, achieving a fully satisfactory dual-sided fiber entangling action.
The difference in operation between embodiments using colinear streams and slightly offset streams resides essentially in the speed o~ fiber entangling. When the streams are colinear, the entangling of the fibers ls almost immediate because the fibers are subjected to intense and localized forces. In contrast, with offset streams, the entangling action is achieved progressively as the fibers move through successive streams.
The individual f luid streams produced by the nozzle banks of manifolds 26 and 28 do not have to be necessarily oriented in the plane containing the drum axis. It may very well be envisaged to rotate or tilt the nozzles to .
- 20 ~ 2022~80 inaline the streams with reference to the drum axis. In such a construction, the overlap between ad~acent streams will be lost because the streams will lie ln respective planes which are parallel to one another and they extend obliquely to the drum axis. Varying the orientation of the fluid streams is an adjustment that can be performed to obtain a uniform web treatment, preventing the formation of fuzziness zones in the final product.
It is also possible to orient the nozzles of the manifolds 26 and 28 at a certain angular relationship so that the fluid streams are not perfectly colinear nor parallel. This variant can also function well at the condition that the fluid streams give rise to fluid forces which have ma~or components applied in opposition along colinear or parallel directions to the web.
The number of nozzles per manifold is a function of the amount of energy per unit of time or power, that must be supplied by the fluid streams to rearrange the fibers of the web into the desired network structure. The type of fibers used, the speed of the web through the fluid streams, among other factors, determine the power requirement of the apparatus.
- 21 - 2~22~80 Although not shown in the drawlngs, it ls to be understood that the manifolds 26 and 28 are connected to respective sources of pressurized fluid, preferably water, for producing the fluid streams. Fluid supply pressure control devices 35, of a type known in the art, are also provided so that the fluid supply pressure in each manifold can be conveniently controlled.
The operation of the fiber rearranging station 10 is as follows. A web 36 of starting material, containing loosely associated fibers, thus capable of movement one relative to the other, is supplled in a continuous 8heet form from a supply station (not shown) that will also card the fibers in the machine direction and is deposited over the horizontally extending forward run of the screen belt 20 prece~ing the section of the screen belt which loops the hollow drum 12. The web 36 is pulled between the hollow drum 12 and the screen belt 20, which form in combination a fluid permeable web confining and supporting structure guiding and advancing the web 36 through the opposed water streams from the manifolds 26 and 28, applying fluid force~ to the web fibers to entangle them and form a unitary reticular network.
- 22 ~ 2022~80 When the web 36 passes through the fluid treatment zone, the flbers ln the area of the web 36 over which the fluld fronts generated by the manlfolds 2~ and 28 meet are subjected to fluld forces applied through respective sides of the fluid permeable web con$ining and supporting structure. Under the effect of coacting fluid forces applied in opposition, the fibers will migrate toward preferential positions, overcoming inter-fiber friction, fiber to ~creen belt frlction and fiber to drum frlction.
The fibers leaving the treatment zone are reoriented into a reticular network whose basic configuration is dependent upon the relative intensities of the fluid forces and upon the drum/screen belt combinatlon, and which has a considerably higher degree of fiber entanglement by comparison to what can be achieved with a conventional method using only one fluid stream, either on the inside or on the outside of the drum.
The fundamental aspect of this invention resides in applying to the web opposite and coacting fluid streams.
Surprisingly, these opposite fluid streams have a synergistic effect, rearranging the fibers into a predetermined network with a higher degree of entanglement by comparison to single sided fluid formation methods.
Another significant advantage which results from the use of opposed fluid streams to rearrange the fibers resides - 23 ~ 2022080 in the lower f luid supply pressure necessary to operate the apparatus whlch contributes to reduce the manufacturing cost of the final product.
Results of tests conducted with an apparatus accordlng to the lnventlon are summarlzed in the following table. Dlfferent fabric samples have been produced by varying the manifold fluid supply pressures. For each ~ample, the following data is reported:
1) Pressure in manifola6 26 and 28 in pounds per square inch gage (psig~;
2) weight (W) in grams per meter squared (g/m2);
3) tensile strength (TS) in Newton per 6 ply (N~6 ply), measured in the machine direction (MD) and in the cross-machlne dlrectlon (CD);
TITLE: LOW FLUID PRES5URE DUAL-SIDED FIBER EN--TAN-GLEMENT
HETHOD, APPARATUS AND RESULTING PRODUCT
FIELD OF THE INVENTION
The invention relates to the general field of fibrous materials and, more particularly, to a novel method for entangling loosely associated fibers to form a unitary reticular network by using fluld streams applied in opposition to the fibers. The invention also extends to an apparatus for carrying out the method and to the resulting product.
BACKGROUND OF THE LNV~;~TlON
Nonwoven fabric3 are well-~uited for applications which require a low cost fibroul3 web. Example~ are disposable artlcles such as polishing or washing cloth3, cast paddings and facing layer3 for fibrous mat products.
Nonwoven fabrics are normally produced from a web of loosely associated fibers that are subjected to a fiber rearranging method to entangle and mechanically interlock the fiber3 lnto a unitary reticular network. The fiber rearrangement i3 achieved under the effect of fluid force~
applied to the fibers through a fluid ~ermeable web - 2 ~ 2022080 confinlng and supparting structure comprising a rigid apertured member with a predetermlned pattern of fluld passages, and a flexible foraminous sheet disposed in a face-to-face relationship to the apertured member. In one form of construction, the rigid apertured member iB a rotating hollow drum and the flexible foraminous sheet is an endless screen belt in overlapping relationship with the hollow drum and advancing therewith. The web of loosely associated fibers which forms the starting material of the nonwoven fabric production method is confined between the drum and the screen belt and i~
advanced through a fluid stream creating the entangling forces on the fibers.
~he so-called "Rosebud" nonwoven fabric production method reguires that the fluid stream be located outside the hollow drum, the fluid partlcles impinging on the fibers through the screen belt. In operation, the fibers are drawn by the fluid mass flowing out of the apertured hollow drum, into the fluid passages thereof, and they are mechanically interlocked and entangled in protuberant packings which are interconnected by flat fiber bundles extending over the land areas of the drum. The resulting nonwoven fabric has a three-dimensional structure presenting a knobby side containing the apexes of the fiber packings, and a ~lat and smoother side containing _ 3 _ 2022080 the base portions of the fiber packings and the interconnecting bundles.
In a variant of the Rosebud method, known as the "Keybak" method, the direction of the fluid stream i3 reversed, whereby the fluid particles reach the fibers by passing through the fluid passages on the drum. In contrast to the Rosebud method, the fibers are packed together on the land areas of the drum forming a network with clear holes arranged into a pattern corresponding to the pattern of fluid passa~es on the hollow drum.
For a wide range of applications, nonwoven fabrics having superior resistance characteristics are required.
Basically, the resistance or durability of a nonwoven fibrous web depends on the degree of fiber entanglement achieved during the fiber rearranging process. When the fibers are tightly interlocked, they form a den~e and tenacious network which is highly resistant to forces tending to destroy the web integrity, such as tear ~orces for example. In contrast, a web constituted by loo~ely associated fibers is substantially less resistant because, at the ~iber Level, the network of the web lacks cohesion.
_ 4 _ 2 02208~
In conventional nonwoven fabric production methods, a certain increa8e in the degree of fiber entanglement may be achieved at the fiber rearranging stage by increasing the fluid supply pressure of the stream in order to augment the intensity of the fluid forces acting on the fibers. However, there are disadvantages and inherent limits in increasing the fluid supply pressure which considerably offset any advantage that may be gained in terms of higher fiber entanglement. Traditional production methods already require fairly high fluid supply pressures and a further pressure increase creates considerable strain on the equipment whlch translates lnto an increa3e of the fabric manufacturing cost. In addition, regardles3 of cost con6ideratlons, the fluid supply pre3sure cannot be indefinitely increased a3 beyond a certaln polnt, a destructive condition known as "floodlng" occurs which is deflned as a loss of web ldentity resulting from the appllcatlon of fluid forces to the fiber which are too intense.
It is also known from the prior art to apply a binder substance to the fiber3 of the fabric subsequently to the fiber rearranging step, in order ~o increase the fabrlc resistance. The binder substance, when cured, establishe3 a bond ~etween ad~acent fiber3 and prevents them to move one relative to the other. Accordingly, the tenacity of - S- 202208~
the fabric will increase because of the reduction in the inter-flber displacement when destructive forces act on the fabric.
Although a binder can effectively increase the resistance of a nonwoven fabric, for cost considerations, it cannot be considered as an ideal solution.
Fundamentally, the ob~ective of any nonwoven fabric production method is to turn out the least expensive product, therefore, it is desirable to eliminate or at least reduce as much as possible the binder application.
OBJECTS AN-D STATEMENT OF THE LNv~b~
An object of the invention is a novel three-dimensional nonwoven fabric having superior resistance characteristics and possessing two textured sides, high bulk, softness, better absorbency and aesthetics.
Another ob~ect of the invention is a novel low pressure fluid formation method and apparatus for producing the aforementioned fabric.
Yet, another object of the invention is a method and an apparatus for fluid formation of nonwoven fabrics allowing a higher level of control of the fabric structure .
s In one aspect, the invention provides a method for fluid formation of a unitary nonwoven fabric, comprising the steps of:
- providlng a fibrous ætarting material whose lndividual fibers are capable of movement relatively to one another under the lnfluence of applied fluid force8;
and - sub~ecting the fibrous starting material to opposed coacting fluid stre~ms while supporting the material between an apertured member having a predetermined pattern of fluld pas~ages therethrough and a foraminous fluid permeable member, whereby under the influence of fluid forces applled ln opposltion, the individual fiberæ of the starting materlal are entangled forming a reticular network which defines a pattern of holes corresponding to the predetermined pattern of fluid passages on the apertured member.
- 7 ~ 2022080 For the purpose of this speclfication, the scope of the expression "opposed coacting fluid streams" is not intended to be restricted to an arrangement where the fluid streams are colinear, but should be con5trued to encompass any form of construction where a given fiber of the starting material is sub~ected simultaneously ~o the influen~e of fluid streams having generally opposite directions. Having regard to the foregoing, an embodiment with slightly offset or staggered fluid streams is considered to meet this definition at the condition that the ma~ority of the fibers in the web of starting material are long enough and are oriented in such a way as to span the offset between the streams. Hence, a given fiber under fluid treatment will be affected simultaneously by the streams, albeit the streams will be acting on different portions of the fiber. The degree of offset between the streams which will determine whether they are coacting or not is primarily a function of fiber length and fiber orientation. In a web formed of short fibers, only a small offset will be allowed, however in a web of longer fibers, it is possible to further space the streams and still retain the benef it of a simultaneous dual stream action on the fibers.
In addition, the respective propagation paths o~ the streams do not necessarily have to be parallel or colinear in order to be characterized by "opposite". This word is to be interpreted ln a broad sense/ as it ls intended to encompass embodiments where the streams are at a certain angular relationship which is such that the streams give rise to fluid forces whose principal components are applied to the web along truly opposite directions.
In a preferred embodimentr the apertured member is a rotating rigid hollow drum while the foraminous ~luid permeable member is an endless screen belt for holding the fibrous starting materLal agalnst the drum. The opposed fluid streams are created by providing inslde and outside of the hollow drum, manifolds with respective ~ets disposed in a face-to-face relatlonship. The fluid mass coming from the manifold positioned outside the hollow drum is diffused through the screen belt and impacts on the fibers drawing them in the fluid passages of the drum as this fluid mass flows therethrough. The opposite ~luid stream produced by the inside manifold passes through the fluid passages and has a tendency to e~ect the fibers out of the fluid passages and to pack them over the land areas of the hollow drum. Surprisingly, it has been found that the fluid forces applied to the fibers in opposition have a synergistic effect, rearranging the fibers into a - 9 - 2~22080 retlcular network having a substantially higher degree of entanglement and cohesion comparatively to what can be achieved with a single-sided fluid formation method, be it the Rosebud or the Beybak method.
The method according to the invention is hi~hly advantageous because it uses a relatively low fluid supply pressurer yet it can deliver a higher fiber entanglement comparatively to single sided fluid formation methods, to produce fabrics which require less binder to achieve predetermined resistance characteristlcs. In addltlon, the method can also increase the fabric performance in bulk, softness, absorbency and texture.
The dual-sided fluid entangling method can achieve dlfferent fabrlc structures by selectively varying the intenslty of the fluld forces actlng in opposition on the fibers. In one extreme condition when only the manifold located lnslde the hollow drum operates, the nonwoven fabric has a network definlng a pattern of clear holes corresponding to the pattern of fluld pa~sages on the hollow drum. Thls fabrlc structure 18 ldentlcal to what can be obtained with the Keybak method.
By actlvatlng the outside manlfold to lmpinge a fluid stream on the flbrous startlng material through the screen belt, the structure of the nonwoven fabric is altered.
The clear holes wlll start closing at the extremity facing the screen belt and a protuberant fiber packing will form at the closed end of each hole. Thls three-dimensional fabric structure i8 novel and constitutes another aspect of the present invention. Conventional three-dimensional fabrics have only one textured side, the other one being flat, while the aforementioned network structure provides a fabric with two textured surfaces having a very distinct appearance and feel. On one side of the fabric are disposed the openings of the blind holes creating a pattern of recesses, the opposite side being knobby as a result of the protuberant f iber packings closing the holes .
Eurther augmenting the velocity of the stream from the outside manifold with respect to the velocity of the stream from the inside manifold will result in a further growth of the fiber packings at the expense of an erosion of the network defining the holes which will become shallower, bringing the fiber packings closer to the drum surf ace .
Shutting down the inside manifold is the other extreme condition. The fiber packings will grow larger and will penetrate into the drum openings. The holes will - 11 - 202208~
disappear creating flat fiber bundles interconnecting the protuberant fiber packings and extending over the land areas of the drum. This fiber structure is eguivalent to what is achieved wlth the Rosebud method.
In summary, each fluid stream imparts a distinct pattern to the web of starting material and when the opposite streams are simultaneously applied to the web, the fibers are tightly entangled into a fabric network where the two patterns coexist. If it is desired that one of the patterns predominates the other, this can be achieved simply by increasing the intensity of the fluid stream creating this pattern relatively to the intensity of the other stream.
The ability of the method to control the fabric structure constitutes another aspect of the invention. In broad terms the method can be expressed as the combination of the following steps:
- providing a fibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces - ~ub~ecting the fibrous starting material to coacting opposed fluid streams while confining the material between spaced apart foraminous members forming a fluid permeable supporting structure, whereby under the - 12- 2~22080 influence of fluid force3 applied in opposition the individual fibers of the material are entangled forming a reticular network; and - controlling the intensity of the fluid forces to control the fiber distribution profile of the network in a trensverse direction to the plane of the nonwoven fabric .
In a further aspect, the invention provides an apparatus for producing a unitary nonwoven fabric from a fibrous 6tarting material whose individual fibers are capable of movement under the influence of applied fluid forces, the apparatus comprising a fiber rearranging station which includes s a) an apertured member having fluid passages therethrough;
b) a foraminous member spaced apart from the apertured member to define therewith a fluid permeable supporting structure for the fibrous starting material;
2 0 and c ) means to generate opposed and coacting f luid streams producing respective fluid forces which are applied in opposition to the starting material through the fluid permeable supporting structure, causing a dual-sided fiber entangling of the starting material to form the nonwoven fabric.
- 13 ~ 2~22080 AdvantageoUsly, the apparatus comprises means to control the intensity of the fluid forces in order to control the nonwoven fabric structure. In a preferred embodiment, the pressure of the fluid supply to the jets producing the streams can be selectively varied to produce the desired fabric network pattern.
As embodied and broadly described herein, the invention provides a method for fluid formation of a unitary nonwoven fabric, comprising the steps of:
- providing a f ibrous starting material whose individual f ibers are capable of movement relatively to one another under the influence of applied fluid forces;
and - subjecting said fibrous starting material to coacting first and second opposed fluid streams while supporting the material between an apertured member having a predetPrm~nPd pattern of fluid passages therethrough and a foraminous fluid permeable member, said first fluid stream acting through said apertured member so as to tend to f orm a pattern of holes in said f ibrous starting material corresponding to said predetermined pattern of fluid passages, said second fluid stream acting through said foraminous member, the force of said second fluid stream relative to said f irst f luid stream being maintained so that said second fluid stream tends to close ...
i,`;
- 13a - 2n22080 t said holes formed by said first fluid stream by packing a portion of said f iber6 into said holes, whereby under the influence of fluid forces applied in opposition, the individual fibers of the material are entangled forming a retioular network of holes at least partially closed by said f iber packings .
As embodied and broadly described herein, the invention also provides a method for fluid formation of a unitary nonwoven fabric, comprising the steps of:
- providing a f ibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces;
- subjecting said fibrous starting material to coacting first and second opposed fluid streams while supporting the material between an apertured member having a predetermined pattern of fluid passages therethrough, and a foraminous fluid permeable member, said first fluid stream acting through said apeL l_UL ~d member so as to tend to form a pattern of holes in said ~ibrous starting material corresponding to said predet~r~ninc~ pattern of fluid passages, said second fluid stream acting through said foraminous member, the force o~ said second fluid stream relative to said first fluid stream being maintained so that said second fluid stream tends to close said holes formed by said first fluid stream by packing a portion of said fibers into said holes, whereby under the - 13b - 2~22080 influence of fluid forces applied in opposition, the individual fibers of the material are entangled forming a reticular network of holes in which f iber packings are formed; and - controlling the intensity of the fluid forces to control the degree to which said fiber packings close said holes .
As embodied and broadly described herein, the invention further provides a method for fluid formation of a unitary nonwoven fabric, comprising the steps of:
- providing a f ibrous starting material whose individual fibers are capable of movement under the influence of applied fluid forces;
- conf ining said f ibrous starting material between first and second fluid permeable members forming a supporting structure, said first member having a plurality of apertures forming a pattern;
- passing said fibrous starting material confined between said f irst and second members through a f luid treatment station comprising opposed f irst and second coacting f luid streams in a staggered relationship producing respective fluid forces which are applied in opposition through said supporting structure, said first fluid stream acting through said apertured member, therQby tending to form a pattern of holes corresponding to said pattern of apertures, said second fluid stream applied in , = .
- 13c ~ 2022D80 opposition to 5aid first fluid stream, thereby tending to close said holes formed by 6aid first fluid stream by packing a portion of said fiber5 into said holes, whereby a progressive dual-sided fiber entangling of said f ibrous starting material occurs 50 as to form the nonwoven fabric having a f irst side in which a pattern of holes are disposed and a second side in which a protuberant f iber packing closes each of said holes.
As embodied and broadly described herein, the invention further provides a method for fluid formation of a tri-dimensional unitary nonwoven fabric, comprising the steps of:
- providing a f ibrous starting material whose individual f ibers are capable of movement relatively to one another under the influence of applied fluid forces;
- subjecting said fibrous starting material to a plurality of coacting first and second opposed fluid streams while confining the material between spaced apart f luid permeable members, whereby under the inf luence of fluid forces applied in opposition the individual fibers of the material are entangled forming a reticular network defining a prede~orm~ d pattern of holes formed by said first fluid stream, each hole extending transversely to the plane of the fabric and containing a protuberant fiber packing formed by said second 5tream and clo5ing said holes, and - 13d - 2022080 - controlling the relative intensity of said ~luid forces of said first and second ~luid streams to control the f iber distribution provide of said network in a transverse direction to the plane of the nonwoven fabric.
BRIBF DE~r~TPTION OP T~IB DRAWING5 - Figure 1 is a schematical view of the fiber rearranging station of an apparatus for producing a nonwoven fabric in accordance with the invention;
- Figure 2 is an enlarged fragmentary side view of the fiber rearranging station, illustrating the manifolds creating the opposed fluid streams;
- Figure 3 is a perspective and ~ further enlarged view of the f iber rearranging station illustrating in addition to Figure 2, the structure of the perforated hollow drum and of the screen belt for holding and advancing fibrous starting material between the fluid str~ams;
- Figure 4 i8 a graph showing the effect of manifold pressure on the tenacity of the nonwoven fabric;
- Figures 5, 6, 7, 8 and 9 are schematical diagrams illustrating how the variation of the intensity of one fluid stream relative to the other fluid steam affects the fiber rearranging process;
- Figure 10 i8 a photomicrograph of a nonwoven fabric produced with the apparatus depicted in Figure~ 1, 2 and 3r showing the side of the fabric which faces the perforated hollow drum;
- Figure 11 is a photomicrograph of a nonwoven fabric produced with the apparatus depicted in Figures 1, 2 and 3~ showlng the slde o~ the fabrlc facing the screen belt;
and - Figure 12 is a schematical view in cross-section of the fabrlc shown in Figures 10 and 11; and Throughout the drawin~s, the same re~erence numerals designate identi~al or similar components.
.
- 15 ~ 202~080 DESCRIPTION OF A ~t;r~;n~rll E~IBODIHENT _ Flgure 1 i5 a schematlcal side view of the fiber rearranglng station of an apparatus used for the manufacture of a nonwoven fabric by applying fluid forces to a web of starting material in which the individual fibers are loosely associated and are free to move one relatively to the other. The fiber rearranging station, identified comprehensively by the reference numeral 10, comprises a hollow metallic drum 12 mounted for rotation about its longitudinal axis into a suitable cradle ~ not shown). A drive mechanism (not shown) is provided to rotate the drum 12 in the counterclockwise direction, as shown by the arrows 14 at a controlled speed. The drive mechanism i8 of a well-known construction and does not form part of thls lnventlon.
The structure of the hollow drum 12 wlll be described with more detail by referring to Figures 2 and 3. The shell of the drum 12 is provided on its entire surface with perforations 16 arranged into a predetermined pattern and separated from one another by land areas 18 corresponding to the closed or impermeable zones of the drum 12. The pattern of the openings 16 is an important factor which determines, in conjunction with other factors, the network structure o~ the nonwoven fabric. In - 16 ~ 2022080 the art of manufacturing nonwoven fabrics, the effect of the perforation scheme on the nonwoven fabrlc structure is well understood by those skilled in the art and it is not deemed necessary here to discuss this matter.
Referring back to Figure 1, the fiber rearranging station 10 also comprises an endless screen belt 20 which is mounted in a partially overlapping relationship to the drum 12 by means of guide rollers 22. Support rollers 24 are positioned at the corners of an imaginary rectangle and act, in con~unction with guide rollers 22, to tension and establish a path for the ~creen belt 20. One or more of the rollers 22 or 24 are drive rollers for advancing the belt 20 in unison with the drum 12, in other words to prevent a relative translatory motion therebetween.
The structure of the screen belt 20 is another factor influencing the network structure of the nonwoven fabric, as it is known to those skilled in the art. Therefore, the screen belt must be selected carefully in accordance with all the other operating conditions o~ the machine, such as the type of drum which is being used, the type of fibers to be processed and the desired fabric network structure and surface finish, amon~ others, to optimize the performance of the machine.
- 17 ~ 2~22080 A pair of manlfolds 26 and 28 are mounted on either slde of the structure formed by the screen belt 20 and the hollow perforated drum 12 to create fluid streams for rearranging loosely associated fibers confined between the drum 12 and the screen belt 20 into a unitary, thin reticular network. The manifold 26 is located outside the hollow drum 12 and includes a metallic box 30 with a concave wall 32 which faces the drum/screen belt and has a curvature corresponding to the curvature of the drum shell. On the concave wall 32 are mounted a series of water jets or nozzles 34 in fluid communication with the interior of the box 30 so as to create a plurality of fluid streams impinging on the screen belt 20. The concave shape of the wall 32 permits the orientation of each jet 34 into a radial direction relative to the drum/
screen belt and also to position the extremity of each nozzle at exactly the same d$stance from the screen belt 20. This feature is best illustrated in Figures 1 and 2.
The nozzles 34 are grouped into four parallel rows, each row extending along the longitudinal axis of the drum 12. The nozzles produce fluid streams under the form of flat cones lying in an imaginary plane which contains the drum longitudinal axis, the nozzles into the same row being spaced from one another by a distance 50 that a certain overlap occurs between streams from ad~acent - 18- 2~22080 nozzles immediately in front of the screen belt 20. The distance between successive nozzle rows is relatively small so that, for all practical purposes, the individual fluid streams produced by the nozzles 34 are united into a common fluid front acting on a given area of the fibrous web ln the drum~screen belt facing the manlfold 26.
The structure of the manifold 28 is essentially the same as in the case of the manifold 26, the only exception being that the front wall of the manifold is convex rather than concave for following the internal curvature of the hollow drum 12, and also six rows of nozzles are provided instead of four.
The individual fluid streams from one manifold do not necessarily have to be colinear with the indlvidual fluid streams from the other manlfold. A certain degree of offset or stagger, elther ln the machine dlrection, the cross-machine directlon or an intermediate direction, is aLlowed upon the conditlon that the majority of the fibers forming the starting material are long enough and oriented in such a way as to span the offset dlstance between two opposite fluld streams, whereby the fibers will be sub~ected to the influence of fluid forces applied in opposition, albeit acting on different portions of a given fiber. The maximum permissible amount of offset depends upon the average f lber length . The orientation of the offset should normally be consistant with the fiber orientation ln the starting material.
The embodiment shown in Figure 2 is an exemplary hybrid form of construction where the two lower nozzle rows of the manifold 26 are perfectly in line with the two lower nozzle rows of the manifold 28, while the two upper nozzle rows of manifold 26 are slightly offset with relation to their companion nozzle rows of manifold 28.
The important point is that the arrangement does not adversely affect the operation o~ the apparatus, achieving a fully satisfactory dual-sided fiber entangling action.
The difference in operation between embodiments using colinear streams and slightly offset streams resides essentially in the speed o~ fiber entangling. When the streams are colinear, the entangling of the fibers ls almost immediate because the fibers are subjected to intense and localized forces. In contrast, with offset streams, the entangling action is achieved progressively as the fibers move through successive streams.
The individual f luid streams produced by the nozzle banks of manifolds 26 and 28 do not have to be necessarily oriented in the plane containing the drum axis. It may very well be envisaged to rotate or tilt the nozzles to .
- 20 ~ 2022~80 inaline the streams with reference to the drum axis. In such a construction, the overlap between ad~acent streams will be lost because the streams will lie ln respective planes which are parallel to one another and they extend obliquely to the drum axis. Varying the orientation of the fluid streams is an adjustment that can be performed to obtain a uniform web treatment, preventing the formation of fuzziness zones in the final product.
It is also possible to orient the nozzles of the manifolds 26 and 28 at a certain angular relationship so that the fluid streams are not perfectly colinear nor parallel. This variant can also function well at the condition that the fluid streams give rise to fluid forces which have ma~or components applied in opposition along colinear or parallel directions to the web.
The number of nozzles per manifold is a function of the amount of energy per unit of time or power, that must be supplied by the fluid streams to rearrange the fibers of the web into the desired network structure. The type of fibers used, the speed of the web through the fluid streams, among other factors, determine the power requirement of the apparatus.
- 21 - 2~22~80 Although not shown in the drawlngs, it ls to be understood that the manifolds 26 and 28 are connected to respective sources of pressurized fluid, preferably water, for producing the fluid streams. Fluid supply pressure control devices 35, of a type known in the art, are also provided so that the fluid supply pressure in each manifold can be conveniently controlled.
The operation of the fiber rearranging station 10 is as follows. A web 36 of starting material, containing loosely associated fibers, thus capable of movement one relative to the other, is supplled in a continuous 8heet form from a supply station (not shown) that will also card the fibers in the machine direction and is deposited over the horizontally extending forward run of the screen belt 20 prece~ing the section of the screen belt which loops the hollow drum 12. The web 36 is pulled between the hollow drum 12 and the screen belt 20, which form in combination a fluid permeable web confining and supporting structure guiding and advancing the web 36 through the opposed water streams from the manifolds 26 and 28, applying fluid force~ to the web fibers to entangle them and form a unitary reticular network.
- 22 ~ 2022~80 When the web 36 passes through the fluid treatment zone, the flbers ln the area of the web 36 over which the fluld fronts generated by the manlfolds 2~ and 28 meet are subjected to fluld forces applied through respective sides of the fluid permeable web con$ining and supporting structure. Under the effect of coacting fluid forces applied in opposition, the fibers will migrate toward preferential positions, overcoming inter-fiber friction, fiber to ~creen belt frlction and fiber to drum frlction.
The fibers leaving the treatment zone are reoriented into a reticular network whose basic configuration is dependent upon the relative intensities of the fluid forces and upon the drum/screen belt combinatlon, and which has a considerably higher degree of fiber entanglement by comparison to what can be achieved with a conventional method using only one fluid stream, either on the inside or on the outside of the drum.
The fundamental aspect of this invention resides in applying to the web opposite and coacting fluid streams.
Surprisingly, these opposite fluid streams have a synergistic effect, rearranging the fibers into a predetermined network with a higher degree of entanglement by comparison to single sided fluid formation methods.
Another significant advantage which results from the use of opposed fluid streams to rearrange the fibers resides - 23 ~ 2022080 in the lower f luid supply pressure necessary to operate the apparatus whlch contributes to reduce the manufacturing cost of the final product.
Results of tests conducted with an apparatus accordlng to the lnventlon are summarlzed in the following table. Dlfferent fabric samples have been produced by varying the manifold fluid supply pressures. For each ~ample, the following data is reported:
1) Pressure in manifola6 26 and 28 in pounds per square inch gage (psig~;
2) weight (W) in grams per meter squared (g/m2);
3) tensile strength (TS) in Newton per 6 ply (N~6 ply), measured in the machine direction (MD) and in the cross-machlne dlrectlon (CD);
4 ) the percentage of elongatlon ( ~ ELONG ) measured ln the machine direction and in the cross-machine direction;
5) the tenacity (TEN) measured in the machine direction and in the cross-machine direction in pounds per ply ( lb/ply) over 100 grains per yard squared ( grains/yd2 ); and - 24 ~ 2022~80 6) a general measure of the sample tenacity (G.
S TE~), reflecting the level of entanglement achieved, which is defined as the square root of the product between the machine direction tenacity and the cross-machine direction tenacity values.
All samples are produced with a screen belt HC-7-800 commercialized by TETC0 INC., having a mesh opening of 800 microns. The hollow drum used has 144 openings per square inch corresponding to a 38% open area. The pattern of lS holes on the drum is such as shown in Figure 2, where the holes are grouped into rows and columns intersecting at right angles. The manifold 26 has four rows of nozzles, each nozzle having a 15-10 size, oriented at 0, i.e. the resulting fluid stream is horizontal. The manifold 28 has six rows of nozzles, each nozzle having a size 15-12, tilted at 45 relatively to the drum axis.
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- 26 ~ 2022080 The general tenacity values of samples 1, 4 and 5 are particularly significant, illustrating the improvement in entanglement that can be achieved with the present method.
Sample 1 has been produced with only one fluid stream at 140 psig generated by the manifold 28 which is located within the hollow drum, the outside manifold 26 being rendered inoperative by shutting down its fluid supply.
The method is therefore equivalent to the Keybak method.
The general tenacity value that has been achleved is 0 . 036 .
Sample 5 has been produced under reversed operating conditions, i.e., manifold 26 is functional at 140 psig while manifold 28 is inoperative. The method is equivalent to the Rosebud method. The general tenacity value is 0.039, virtually the same as in the case with sample 1.
Sample 4 has been produced with both manifolds operating at 140 psig, the same fluid supply pressure used with samples 1 and 5. The general tenacity value achieved is 0.157, an improvement of over 400% by comparison to samples 1 and 5 produced with prior art single sided fluid formation methods.
The graph in Flgure 4 illustrates the effect of manifold pressure on the general fabric tenacity. The fabric used for the test has a weight of approxlmately 40 g/m2 ~
s The fluid supply pressure of manifold 26 appears on the X axls. The general fabrlc tenaclty appears on the Y
axls. Varlou6 curves are plotted for glven fluld supply pressures of the manlfold 28. The graph shows that the tenaclty of the fabrlc lncreaæes aæ the fluid supply pressure in either manifold increases. The higher tenacity values are achieved as a result of relatively hlgh fluid supply pressures in each manifold.
The above table and the graph in Figure 4, also illustrate another advantage of the method according to the invention residing in the low fluid supply pressure necessary to entangle the fibers. In all cases, fluid supply pre~sures not exceeding 220 psig have been used, which is considerably less than conventional processes that may require pressures above 1000 psig.
The fiber rearranging process which occurs under the operating conditions corresponding to sample 1, is schematically illustrated in Figure 5. Only the manifold 28 1~ operatlve, projectlng fluld streams agalnst the - 28 ~ 2022080 internal surface of the hollow drum 12. The fluid mass flows through the openings 16, packing the individual flbers of the web 36 on the land areas 18 of the drum.
The resulting fabric network structure i8 identical to what is achieved with the Keybak method, i . e. having a pattern of clear holes in register with the drum openings 16 .
The f iber rearranging process corresponding to sample 2 is shown in Figure 6. Both manifolds operate, the inside manifold being supplied with fluid under a higher pressure than the outside manifold. The fluid force acting on the web 36 through the screen belt 20 starts closing the hole8 produced by the fluid mass flowing out of the drum 12. Packings of fibers, identified by the reference numeral 37, starts forming at the closed end3 of the fabric holes.
Figure 7 illustrates the f iber rearranging procesY
corresponding to 3ample 3. The fluid forces acting on either side of the web 36 have the same intensity as the fluid supply pressure to each mani~old iB the same. Under these operating conditions, a certain equilibrium between the effect of each stream on the web iB noted. By comparison to the previous Figure, the packings 37 are no~d clearly visible as a re~ult of a fiber migration from the network def ining the holes to the packings 37 .
Accordingly, the holes in the fabrlc are shallower which has the effect of bringing the packings 37 closer to the drum outside surface.
s Figure 8, corresponding to the fiber rearranging process of sample 4, illustrates what occurs when the intensity of the outside stream is higher than the intensity of the stream produced inside the drum 12. The packings 37 have grown larger at the eYpense of the fabric network which defines the holes, and are closer to the drum outside surface.
Figure 9, corresponding to the fiber rearranging proces of sample 5, shows what happens when the internal manifold is shut down. The resulting i~abric structure exhibits large fiber packings sitting in the openings 16 of the drum 12. The original structure of holes has disappeared. The only fibers remaining on the land areas 18 of the drum 12 serve to interconnect the fiber packings 37. This fabric network structure corresponds to what is achieved with the Rosebud method.
The ability of the method for manufacturing a nonwoven fabric to control the fabric network structure by adjusting the relatlve intensities of the fiber ~30- 2a22~80 entangling fluld forces constitutes another important advantage of the invention. With this method, it becomes very easy to fine tune the fabric structure for specific applications æimply by selectively varying the manifold fluid supply pressure. The fluid streams impart respective and distinct patterns to the fabric, which coeYist in the final product. More specifically, the fluid stream from the manifold 28 creates the holes in the fabric. The fluid stream from the manifold 26 closes the holes, producing a protuberant fiber packing or knob at the end of each hole. One pattern can be made predominant simply by increasing the velocity of the fluid stream providing this pattern relatively to the velocity of the other fluid stream.
The nonwoven fabric network structures obtained under the operating conditions depicted in Figures 6 to 8 are novel. Figures 10 and 11 are photomicrographs of the respective sides of the preferred fabric structure obtained by the setup of Figure 8, while Figure 12 is a schematical illustration depicting the cross-sectional fiber distribution pattern across the fabric. As it is shown in Figure 10, the fabric has a highly cohesive reticular network, the holes which extend transversely to the plane of the fabric are identified by the reference numeral 38. The holes 38 are closed at one extremity by 2022~80 the protuberant fiber packings or knobs 37, best shown in Flgure 11. The fabric has two textured sides, one includlng a pattern of recesses formed by the openlngs of the blind holes 38, the other side having a knobby surface resultlng from the apexes of the protuberant fiber packings 37. Accordingly, the fabric has a very distinct feel, one surface being knobby and the other surface contalning the openlngs of the holes 38, being much 80 f te r .
The starting materlal 36 used wlth the method and apparatus of thls lnventlon can be any of the standard fibrous webs such as oriented card webs, isowebs, air-laid webs or webs formed by liquid deposition. The webs may be formed ln a single layer or by laminatlng a plurallty of the webs together. The fibers ln the web may be arranged in a random manner or may be more or less orlented as ln the card web. The lndlvldual flbers may be relatively straight or slightly bent. The fibers intersect at various angles to one another such that ad~acent fibers come into contact only at the points where they cross.
Possible types of fibers are polyester rayon, cotton, bico, polypropylene, nylon, acrylic, and mixtures thereof, among others.
- 32 ~ 2~22080 If it ls desired to increase the resistance of the fabric accordlng to the invention, a binder substance may be applled in a known fashlon. Posslble binder substances are acrylic, ethylene vinyl, vlnyl chloride, vinyl S acetate, polyvlnyl alcohol, polyvinyl acetate, carboxilated polystyrene, rubber and polyethylene emulsion and mixtures thereof, among others. The binder substance may be incorporated directly in the fiber entangling fluid streams to treat the fabric simultaneously during the fiber entangling step. The fluid streams may also be used as a vehicle to apply a fire retardant composition, a coloring die or any other suitable agent to the fabric.
As stated earlier, the novel fabric structure has a distinctive appearance, ~oftness and feel. It has been found that it ls partlcularly well suited for maklng general purpose wlplng cloths. When compared to commerically available wiping cloths, such as the J-cloth~
( trademark of Johnson & Johnson ), it has superior performance in various categories, as summarized ln the followlng table, yet belng made with less blnder than the J-cloth, whlch provldes a conslderable advantage ln terms of manufacturing costs.
FABRIC ACCORDING
TO TIIE INVENTION J-CLOTEi Blnder (% per weight) 15 19 Weight ( g/m2 ) 53 . 2 52 . 2 Tensile strength M. D.
(Newton) 367 342 Tensile strength C. D .
( Newton ) 57 47 . 8 Bulk (4 ply per inch) 0.083 0.060 Absorptive capaci~y ( % ) 1005 828 Absorbency rate ( seconds ) 1. 2 1. 6 Washability (cycles) 120 100 The above description of preferred embodiments should not be interpreted in any limiting manner as these embodiment3 may be refined without departing from the spirit of the invention. The scope of the invention is defined in the appended claim3.
S TE~), reflecting the level of entanglement achieved, which is defined as the square root of the product between the machine direction tenacity and the cross-machine direction tenacity values.
All samples are produced with a screen belt HC-7-800 commercialized by TETC0 INC., having a mesh opening of 800 microns. The hollow drum used has 144 openings per square inch corresponding to a 38% open area. The pattern of lS holes on the drum is such as shown in Figure 2, where the holes are grouped into rows and columns intersecting at right angles. The manifold 26 has four rows of nozzles, each nozzle having a 15-10 size, oriented at 0, i.e. the resulting fluid stream is horizontal. The manifold 28 has six rows of nozzles, each nozzle having a size 15-12, tilted at 45 relatively to the drum axis.
`, 5 - ` \
2Q22~80 ,~ N U- ~ o O O O O O
O O O O O
~ V O O O O O
Z ~ d' ~ ~ O O O .1 0 V O o o N N
V ,., d, r~ 1~
_I O O 0: 0 01 ~ N ~) N
~ d' d' O O O O O rl N ~ N d' _ 11 3 - D. n o s~
C~ ~ ~ d' ~ --O
s~ o.
o _ n ~
.. . . .
- 26 ~ 2022080 The general tenacity values of samples 1, 4 and 5 are particularly significant, illustrating the improvement in entanglement that can be achieved with the present method.
Sample 1 has been produced with only one fluid stream at 140 psig generated by the manifold 28 which is located within the hollow drum, the outside manifold 26 being rendered inoperative by shutting down its fluid supply.
The method is therefore equivalent to the Keybak method.
The general tenacity value that has been achleved is 0 . 036 .
Sample 5 has been produced under reversed operating conditions, i.e., manifold 26 is functional at 140 psig while manifold 28 is inoperative. The method is equivalent to the Rosebud method. The general tenacity value is 0.039, virtually the same as in the case with sample 1.
Sample 4 has been produced with both manifolds operating at 140 psig, the same fluid supply pressure used with samples 1 and 5. The general tenacity value achieved is 0.157, an improvement of over 400% by comparison to samples 1 and 5 produced with prior art single sided fluid formation methods.
The graph in Flgure 4 illustrates the effect of manifold pressure on the general fabric tenacity. The fabric used for the test has a weight of approxlmately 40 g/m2 ~
s The fluid supply pressure of manifold 26 appears on the X axls. The general fabrlc tenaclty appears on the Y
axls. Varlou6 curves are plotted for glven fluld supply pressures of the manlfold 28. The graph shows that the tenaclty of the fabrlc lncreaæes aæ the fluid supply pressure in either manifold increases. The higher tenacity values are achieved as a result of relatively hlgh fluid supply pressures in each manifold.
The above table and the graph in Figure 4, also illustrate another advantage of the method according to the invention residing in the low fluid supply pressure necessary to entangle the fibers. In all cases, fluid supply pre~sures not exceeding 220 psig have been used, which is considerably less than conventional processes that may require pressures above 1000 psig.
The fiber rearranging process which occurs under the operating conditions corresponding to sample 1, is schematically illustrated in Figure 5. Only the manifold 28 1~ operatlve, projectlng fluld streams agalnst the - 28 ~ 2022080 internal surface of the hollow drum 12. The fluid mass flows through the openings 16, packing the individual flbers of the web 36 on the land areas 18 of the drum.
The resulting fabric network structure i8 identical to what is achieved with the Keybak method, i . e. having a pattern of clear holes in register with the drum openings 16 .
The f iber rearranging process corresponding to sample 2 is shown in Figure 6. Both manifolds operate, the inside manifold being supplied with fluid under a higher pressure than the outside manifold. The fluid force acting on the web 36 through the screen belt 20 starts closing the hole8 produced by the fluid mass flowing out of the drum 12. Packings of fibers, identified by the reference numeral 37, starts forming at the closed end3 of the fabric holes.
Figure 7 illustrates the f iber rearranging procesY
corresponding to 3ample 3. The fluid forces acting on either side of the web 36 have the same intensity as the fluid supply pressure to each mani~old iB the same. Under these operating conditions, a certain equilibrium between the effect of each stream on the web iB noted. By comparison to the previous Figure, the packings 37 are no~d clearly visible as a re~ult of a fiber migration from the network def ining the holes to the packings 37 .
Accordingly, the holes in the fabrlc are shallower which has the effect of bringing the packings 37 closer to the drum outside surface.
s Figure 8, corresponding to the fiber rearranging process of sample 4, illustrates what occurs when the intensity of the outside stream is higher than the intensity of the stream produced inside the drum 12. The packings 37 have grown larger at the eYpense of the fabric network which defines the holes, and are closer to the drum outside surface.
Figure 9, corresponding to the fiber rearranging proces of sample 5, shows what happens when the internal manifold is shut down. The resulting i~abric structure exhibits large fiber packings sitting in the openings 16 of the drum 12. The original structure of holes has disappeared. The only fibers remaining on the land areas 18 of the drum 12 serve to interconnect the fiber packings 37. This fabric network structure corresponds to what is achieved with the Rosebud method.
The ability of the method for manufacturing a nonwoven fabric to control the fabric network structure by adjusting the relatlve intensities of the fiber ~30- 2a22~80 entangling fluld forces constitutes another important advantage of the invention. With this method, it becomes very easy to fine tune the fabric structure for specific applications æimply by selectively varying the manifold fluid supply pressure. The fluid streams impart respective and distinct patterns to the fabric, which coeYist in the final product. More specifically, the fluid stream from the manifold 28 creates the holes in the fabric. The fluid stream from the manifold 26 closes the holes, producing a protuberant fiber packing or knob at the end of each hole. One pattern can be made predominant simply by increasing the velocity of the fluid stream providing this pattern relatively to the velocity of the other fluid stream.
The nonwoven fabric network structures obtained under the operating conditions depicted in Figures 6 to 8 are novel. Figures 10 and 11 are photomicrographs of the respective sides of the preferred fabric structure obtained by the setup of Figure 8, while Figure 12 is a schematical illustration depicting the cross-sectional fiber distribution pattern across the fabric. As it is shown in Figure 10, the fabric has a highly cohesive reticular network, the holes which extend transversely to the plane of the fabric are identified by the reference numeral 38. The holes 38 are closed at one extremity by 2022~80 the protuberant fiber packings or knobs 37, best shown in Flgure 11. The fabric has two textured sides, one includlng a pattern of recesses formed by the openlngs of the blind holes 38, the other side having a knobby surface resultlng from the apexes of the protuberant fiber packings 37. Accordingly, the fabric has a very distinct feel, one surface being knobby and the other surface contalning the openlngs of the holes 38, being much 80 f te r .
The starting materlal 36 used wlth the method and apparatus of thls lnventlon can be any of the standard fibrous webs such as oriented card webs, isowebs, air-laid webs or webs formed by liquid deposition. The webs may be formed ln a single layer or by laminatlng a plurallty of the webs together. The fibers ln the web may be arranged in a random manner or may be more or less orlented as ln the card web. The lndlvldual flbers may be relatively straight or slightly bent. The fibers intersect at various angles to one another such that ad~acent fibers come into contact only at the points where they cross.
Possible types of fibers are polyester rayon, cotton, bico, polypropylene, nylon, acrylic, and mixtures thereof, among others.
- 32 ~ 2~22080 If it ls desired to increase the resistance of the fabric accordlng to the invention, a binder substance may be applled in a known fashlon. Posslble binder substances are acrylic, ethylene vinyl, vlnyl chloride, vinyl S acetate, polyvlnyl alcohol, polyvinyl acetate, carboxilated polystyrene, rubber and polyethylene emulsion and mixtures thereof, among others. The binder substance may be incorporated directly in the fiber entangling fluid streams to treat the fabric simultaneously during the fiber entangling step. The fluid streams may also be used as a vehicle to apply a fire retardant composition, a coloring die or any other suitable agent to the fabric.
As stated earlier, the novel fabric structure has a distinctive appearance, ~oftness and feel. It has been found that it ls partlcularly well suited for maklng general purpose wlplng cloths. When compared to commerically available wiping cloths, such as the J-cloth~
( trademark of Johnson & Johnson ), it has superior performance in various categories, as summarized ln the followlng table, yet belng made with less blnder than the J-cloth, whlch provldes a conslderable advantage ln terms of manufacturing costs.
FABRIC ACCORDING
TO TIIE INVENTION J-CLOTEi Blnder (% per weight) 15 19 Weight ( g/m2 ) 53 . 2 52 . 2 Tensile strength M. D.
(Newton) 367 342 Tensile strength C. D .
( Newton ) 57 47 . 8 Bulk (4 ply per inch) 0.083 0.060 Absorptive capaci~y ( % ) 1005 828 Absorbency rate ( seconds ) 1. 2 1. 6 Washability (cycles) 120 100 The above description of preferred embodiments should not be interpreted in any limiting manner as these embodiment3 may be refined without departing from the spirit of the invention. The scope of the invention is defined in the appended claim3.
Claims (87)
1. A nonwoven three-dimensional fabric comprising a unitary reticular network of fibers in mechanical engagement one with another, defining a predetermined pattern of blind holes, each hole extending transversely to the plane of the fabric and containing a protuberant fiber packing at a closed end thereof, one side of said fabric containing a pattern of recesses corresponding to openings of said blind holes, the other side of said fabric having a knobby surface containing apexes of the protuberant fiber packings.
2. A nonwoven three-dimensional fabric as defined in claim 1, wherein said openings are all disposed on the same side of the fabric.
3. A nonwoven three-dimensional fabric as defined in claim 1, wherein said apexes are all disposed on the same side of the fabric.
4. A nonwoven three-dimensional fabric as defined in claim 1, comprising a binder effecting a bond between fibers of said network.
5. A three-dimensional nonwoven fabric as defined in claim 1, wherein said fibers are selected from the group consisting of polyester, rayon, cotton, bico, polypropylene, nylon, acrylic and mixtures thereof.
6. A three-dimensional nonwoven fabric as defined in claim 4, wherein said binder is selected from the group consisting of vinyl ethylene, vinyl chloride, vinyl acetate, polyvinyl alcohol, acrylic, polyvinyl acetate, carboxylated polystyrene, rubber, polyethylene emulsion and mixtures thereof.
7. A three-dimensional nonwoven fabric comprising fibers in mechanical engagement one with another arranged solely under the influence of fluid forces in a unitary reticular fibrous network which defines a predetermined pattern of blind holes, each hole extending transversely to the plane of the fabric and containing a protuberant fiber packing at a closed end thereof.
8. A method for fluid formation of a unitary nonwoven fabric, comprising the steps of:
- providing a fibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces;
and - subjecting said fibrous starting material to coacting opposed fluid streams while supporting the material between an apertured member having a predetermined pattern of fluid passages therethrough and a foraminous fluid permeable member, whereby under the influence of fluid forces applied in opposition, the individual fibers of the material are entangled forming a reticular network which defines a pattern of holes corresponding to said predetermined pattern of fluid passages.
- providing a fibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces;
and - subjecting said fibrous starting material to coacting opposed fluid streams while supporting the material between an apertured member having a predetermined pattern of fluid passages therethrough and a foraminous fluid permeable member, whereby under the influence of fluid forces applied in opposition, the individual fibers of the material are entangled forming a reticular network which defines a pattern of holes corresponding to said predetermined pattern of fluid passages.
9. A method as defined in claim 8, wherein each fluid stream is a combination of a plurality of independent streams.
10. A method as defined in claim 9, wherein said independent streams are longitudinally and transversely spaced from one another relatively to said fibrous starting material.
11. A method as defined in claim 8, comprising the step of continuously passing fibrous starting material between said coacting opposed fluid streams.
12. A method as defined in claim 11, comprising the step of advancing said apertured and foraminous members through said coacting opposed fluid streams for continuously processing fibrous starting material by said coacting opposed fluid streams.
13. A method as defined in claim 12, wherein said apertured member is a hollow drum, comprising the step of rotating said drum.
14. A method as defined in claim 13, wherein said foraminous fluid permeable member is a screen belt, comprising the steps of locating said screen belt in at least partially overlapping relationship to said drum and advancing said screen belt at a speed to prevent a substantial translatory movement between said screen belt and said drum.
15. A method as defined in claim 8, comprising the step of carding the individual fibers of said fibrous starting material in a machine direction prior to passing said fibrous starting material between said coacting opposed fluid streams.
16. A method as defined in claim 8, comprising the step of applying a binder to said fibers for effecting a bond therebetween.
17. A method as defined in claim 8, wherein the fibers of said fibrous starting material are selected from the group consisting of polyester, rayon, cotton, bico, polypropylene, nylon, acrylic and mixtures thereof.
18. A method as defined in claim 16, wherein said binder is selected from the group consisting of vinyl ethylene, vinyl chloride, vinyl acetate, polyvinyl alcohol, acrylic, polyvinyl acetate, carboxylated polystyrene, rubber, polyethylene emulsion and mixtures thereof.
19. A method as defined in claim 8, comprising the step of incorporating into at least one of said coacting opposed fluid streams a certain substance for conditioning said nonwoven fabric, whereby the stream constitutes a vehicle for applying said substance to said fibers.
20. A method as defined in claim 8, comprising the step of controlling the degree of fiber entanglement in the nonwoven fabric by controlling the velocity of said coacting opposed fluid streams.
21. A method as defined in claim 20, comprising the steps of providing a pair of manifolds with respective jet means to create said coacting opposed fluid streams, and maintaining a fluid supply pressure in each manifold in the range from 0 to approximately 220 psi.
22. A method as defined in claim 14, comprising the steps of providing a pair of manifolds with respective jet means to create said coacting opposed fluid streams, locating one of said manifolds within said drum and the other of said manifolds outside of said drum with the jet means of the manifolds in a face-to-face relationship, and controlling the fluid supply pressure in each manifold in order to control the degree of fiber entanglement in the nonwoven fabric.
23. A method as defined in claim 22, comprising the step of maintaining a fluid supply pressure in each manifold within the range from 0 to approximately 220 psi.
24. A method as defined in claim 22, comprising the step of maintaining approximately the same fluid supply pressure in each manifold.
25. A method as defined in claim 22, comprising the step of establishing a fluid supply pressure differential between said manifolds.
26. A method as defined in claim 25, comprising the step of establishing a higher fluid supply pressure in the manifold located within said drum.
27. A method as defined in claim 25, comprising the step of establishing a higher fluid supply pressure in the manifold located outside said drum.
28. An apparatus for producing a unitary nonwoven fabric from a fibrous starting material in sheet form whose individual fibers are aapable of movement under the influence of applied fluid foraes, said apparatus comprising a fiber rearranging station, includings a) an apertured member having a predetermined pattern of fluid passages therethrough;
b) a foraminous member spaced apart from said apertured member to define therewith a fluid permeable supporting structure for said fibrous starting material;
and c) means to generate opposed and coacting fluid streams producing respective fluid forces which are applied in opposition to said starting material through said fluid permeable supporting structure, causing a dual-sided fiber entangling of said 6tarting material to form the nonwoven fabric.
b) a foraminous member spaced apart from said apertured member to define therewith a fluid permeable supporting structure for said fibrous starting material;
and c) means to generate opposed and coacting fluid streams producing respective fluid forces which are applied in opposition to said starting material through said fluid permeable supporting structure, causing a dual-sided fiber entangling of said 6tarting material to form the nonwoven fabric.
29. An apparatus as defined in claim 28, comprising means to move said members in unison through said coacting opposed fluid streams for continuously processing starting material in said fiber rearranging station.
30. An apparatus as defined in claim 29, wherein said apertured member is a hollow drum and said foraminous member is a screen belt in at least a partially overlapping relationship with said drum for holding the starting material against said drum.
31. An apparatus as defined in claim 28, wherein said means for producing opposed fluid streams comprises jet means in a face-to-face relationship coupled to a fluid supply means.
32. An apparatus as defined in claim 31, wherein said means for producing opposed fluid streams comprises a pair of manifolds on either side of said fluid permeable supporting structure, a plurality of jets on each manifold, spaced apart from one another thereon, said manifolds being coupled to said fluid supply means.
33. An apparatus as defined in claim 32, wherein said apertured member is a hollow drum and said foraminous member is a screen belt in at least a partially overlapping relationship with said drum for holding the starting material against said drum, one of said manifolds being positioned within said drum with the jets thereof oriented toward an internal wall of said drum, the other of said manifolds being positioned outside of said drum with the jets thereof oriented toward said screen belt.
34. An apparatus as defined in claim 32, wherein some of said jets are spaced in a longitudinal direction and others in a transverse direction on the manifold.
35. An apparatus as defined in claim 28, comprising means upstream of said fiber rearranging station for carding the fibers of the starting material in a machine direction.
36. An apparatus as defined in claim 28, comprising means to apply a binder to effect a bond between fibers of said network.
37. An apparatus as defined in claim 28, wherein said individual fibers are selected from the group consisting of polyester, rayon, cotton, bico, polypropylene, nylon, acrylic and mixtures thereof.
38. An apparatus as defined in claim 36, wherein said binder is selected from the group consisting of vinyl ethylene, vinyl chloride, vinyl acetate, polyvinyl alcohol, acrylic, polyvinyl acetate, carboxylated polystyrene, rubber, polyethylene emulsion and mixtures thereof.
39. An apparatus as defined in claim 28, comprising means for controlling the velocity of each fluid stream to control the structure of said nonwoven fabric.
40. An apparatus as defined in claim 33, further comprising means to control a fluid supply pressure to each manifold to control the velocity of each fluid stream for in turn controlling the structure of said nonwoven fabric.
41. An apparatus as defined in claim 40, comprising means to establish a pressure differential between the fluid supplies to the manifolds.
42. An apparatus as defined in claim 41, comprising means to establish a higher fluid supply pressure to the manifold positioned within said drum.
43. An apparatus as defined in claim 41, comprising means to establish a higher fluid supply pressure to the manifold positioned outside of said drum.
44. A method for fluid formation of a unitary nonwoven fabric, comprising the steps of, - providing a fibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces;
- subjecting said fibrous starting material to coacting opposed fluid streams while supporting the material between an apertured member having a predetermined pattern of fluid passages therethrough, and a foraminous fluid permeable member, whereby under the influence of fluid forces applied in opposition, the individual fibers of the material are entangled forming a reticular network which defines a pattern of holes corresponding to said predetermined pattern of fluid passages; and - controlling the intensity of the fluid forces to control the structure of said network.
- subjecting said fibrous starting material to coacting opposed fluid streams while supporting the material between an apertured member having a predetermined pattern of fluid passages therethrough, and a foraminous fluid permeable member, whereby under the influence of fluid forces applied in opposition, the individual fibers of the material are entangled forming a reticular network which defines a pattern of holes corresponding to said predetermined pattern of fluid passages; and - controlling the intensity of the fluid forces to control the structure of said network.
45. A method as defined in claim 44, comprising the step of controlling the velocity of said fluid streams to control the intensity of said fluid forces.
46. A method as defined in claim 45, comprising the step of establishing a velocity differential between fluid steams.
47. A method as defined in claim 45, comprising the step of producing fluid streams having approximately the same velocity.
48. A method for fluid formation of a tri-dimensional unitary nonwoven fabric, comprising the steps of:
- providing a fibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces;
- subjecting said fibrous starting material to coacting opposed fluid streams while confining the material between spaced apart fluid permeable members, whereby under the influence of fluid forces applied in opposition the individual fibers of the material are entangled forming a reticular network; and - controlling the intensity of said fluid forces to control the fiber distribution profile of said network in a transverse direction to the plane of the nonwoven fabric.
- providing a fibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces;
- subjecting said fibrous starting material to coacting opposed fluid streams while confining the material between spaced apart fluid permeable members, whereby under the influence of fluid forces applied in opposition the individual fibers of the material are entangled forming a reticular network; and - controlling the intensity of said fluid forces to control the fiber distribution profile of said network in a transverse direction to the plane of the nonwoven fabric.
49. A method as defined in claim 48, comprising the step of controlling the velocity of one fluid stream relatively to the velocity of an opposite fluid stream to control the intensity of said fluid forces.
50. A method as defined in claim 48, comprising the steps of positioning said members between a pair of manifolds comprising respective jet means in a face-to-face relationship creating said opposed fluid streams, controlling a fluid supply pressure to each manifold to control the intensity of the fluid forces entangling said individual fibers.
51. A method as defined in claim 50, comprising the step of selectively varying the fluid supply pressure to one manifold relatively to the fluid supply pressure to the other manifold for altering the fiber distribution profile of said network in a transverse direction to the plane of the nonwoven fabric.
52. A method for fluid formation of a unitary nonwoven fabric, comprising the steps of:
- providing a fibrous starting material whose individual fibers are capable of movement under the influence of applied fluid forces;
- confining said fibrous starting material between fluid permeable members forming a supporting structure;
- passing said fibrous starting material in a confined condition through a fluid treatment station comprising opposed and coacting fluid streams in a staggered relationship producing respective fluid forces which are applied in opposition to the fibrous starting material through said supporting structure, causing a progressive dual-sided fiber entangling of said fibrous starting material to form the nonwoven fabric.
- providing a fibrous starting material whose individual fibers are capable of movement under the influence of applied fluid forces;
- confining said fibrous starting material between fluid permeable members forming a supporting structure;
- passing said fibrous starting material in a confined condition through a fluid treatment station comprising opposed and coacting fluid streams in a staggered relationship producing respective fluid forces which are applied in opposition to the fibrous starting material through said supporting structure, causing a progressive dual-sided fiber entangling of said fibrous starting material to form the nonwoven fabric.
53. An apparatus for producing a unitary nonwoven fabric from a fibrous starting material in sheet form whose individual fibers are capable of movement under the influence of applied fluid forces, said apparatus comprising a fiber rearranging station, including, - two fluid permeable members spaced apart from one another defining a supporting structure for confining said fibrous starting material; and - means for advancing said fibrous starting material while in a confined condition through a fluid treatment zone comprising opposed and coacting fluid streams in a staggered relationship producing respective fluid forces applied in opposition to said fibrous starting material through said supporting structure, causing a progressive dual-sided fiber entangling of said fibrous starting material to form the nonwoven fabric.
54. A method for fluid formation of a tri-dimensional unitary nonwoven fabric, comprising the steps of:
providing a fibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces;
- subjecting said fibrous starting material to coacting opposed fluid streams while confining the material between spaced apart fluid permeable members, whereby under the influence of fluid forces applied in opposition the individual fibers of the material are entangled forming a reticular network defining a predetermined pattern of blind holes, each hole extending transversely to the plane of the fabric and containing a protuberant fiber packing at a closed end thereof; and - controlling the intensity of said fluid forces to control the fiber distribution profile of said network in a transverse direction to the plane of the nonwoven fabric.
providing a fibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces;
- subjecting said fibrous starting material to coacting opposed fluid streams while confining the material between spaced apart fluid permeable members, whereby under the influence of fluid forces applied in opposition the individual fibers of the material are entangled forming a reticular network defining a predetermined pattern of blind holes, each hole extending transversely to the plane of the fabric and containing a protuberant fiber packing at a closed end thereof; and - controlling the intensity of said fluid forces to control the fiber distribution profile of said network in a transverse direction to the plane of the nonwoven fabric.
55. A method as defined in claim 54, comprising the step of increasing the velocity of one fluid stream relatively to the velocity of the other fluid stream to increase the size of the protuberant fiber packings and to decrease the size of the blind holes.
56. A method as defined in claim 54, comprising the step of increasing the velocity of one fluid stream relatively to the velocity of the other fluid stream to increase the size of the blind holes and to decrease the size of the protuberant fiber packings.
57. An apparatus for producing a three-dimensional unitary nonwoven fabric from a fibrous starting material in sheet form whose individual fibers are capable of movement under the influence of applied fluid forces, said apparatus comprising a fiber rearranging station, including:
- two fluid permeable spaced apart from one another defining a supporting structure for confining said fibrous starting material; and - means for advancing said fibrous starting material while in a confined condition through a fluid treatment zone comprising opposed and coacting fluid streams, whereby respective fluid forces applied in opposition to said fibrous starting material through said supporting structure, causing a dual-sided fiber entangling of said fibrous starting material to form a nonwoven fabric having a network defining a pattern of blind holes, each hole extending transversely to the plane of the fabric and containing a protuberant fiber packing at a closed end thereof; and - means for controlling the intensity of said fluid forces to control the fiber distribution profile of said network in a transverse direction to the plane of the fabric .
- two fluid permeable spaced apart from one another defining a supporting structure for confining said fibrous starting material; and - means for advancing said fibrous starting material while in a confined condition through a fluid treatment zone comprising opposed and coacting fluid streams, whereby respective fluid forces applied in opposition to said fibrous starting material through said supporting structure, causing a dual-sided fiber entangling of said fibrous starting material to form a nonwoven fabric having a network defining a pattern of blind holes, each hole extending transversely to the plane of the fabric and containing a protuberant fiber packing at a closed end thereof; and - means for controlling the intensity of said fluid forces to control the fiber distribution profile of said network in a transverse direction to the plane of the fabric .
58. An apparatus as defined in claim 57, comprising means to increase the velocity of one fluid stream relatively to the velocity of an opposite fluid stream for increasing the size of the protuberant fiber packings and to decrease the size of the blind holes.
59. An apparatus as defined in claim 57, comprising means to increase the velocity of one fluid stream relatively to the velocity of an opposite fluid stream for increasing the size of the blind holes and to decrease the size of the protuberant fiber packings.
60. A method for fluid formation of a unitary nonwoven fabric, comprising the steps of:
- providing a fibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces;
and - subjecting said fibrous starting material to coacting first and second opposed fluid streams while supporting the material between an apertured member having a predetermined pattern of fluid passages therethrough and a foraminous fluid permeable member, said first fluid stream acting through said apertured member so as to tend to form a pattern of holes in said fibrous starting material corresponding to said predetermined pattern of fluid passages, said second fluid stream acting through said foraminous member, the force of said second fluid stream relative to said first fluid stream being maintained so that said second fluid stream tends to close said holes formed by said first fluid stream by packing a portion of said fibers into said holes, whereby under the influence of fluid forces applied in opposition, the individual fibers of the material are entangled forming a reticular network of holes at least partially closed by said fiber packings,
- providing a fibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces;
and - subjecting said fibrous starting material to coacting first and second opposed fluid streams while supporting the material between an apertured member having a predetermined pattern of fluid passages therethrough and a foraminous fluid permeable member, said first fluid stream acting through said apertured member so as to tend to form a pattern of holes in said fibrous starting material corresponding to said predetermined pattern of fluid passages, said second fluid stream acting through said foraminous member, the force of said second fluid stream relative to said first fluid stream being maintained so that said second fluid stream tends to close said holes formed by said first fluid stream by packing a portion of said fibers into said holes, whereby under the influence of fluid forces applied in opposition, the individual fibers of the material are entangled forming a reticular network of holes at least partially closed by said fiber packings,
61. A method as defined in claim 60, wherein each fluid stream is a combination of a plurality of independent streams.
62. A method as defined in claim 61, wherein said independent streams are longitudinally and transversely spaced from one another relatively to said fibrous starting material.
63. A method as defined in claim 60, comprising the step of continuously passing fibrous starting material between said coacting opposed fluid streams.
64. A method as defined in claim 63, comprising the step of advancing said apertured and foraminous members through said coacting opposed fluid streams for continuously processing fibrous starting material by said coacting opposed fluid streams.
65. A method as defined in claim 64, wherein said apertured member is a hollow drum, comprising the step of rotating said drum.
66. A method as defined in claim 65, wherein said foraminous fluid permeable member is a screen belt, comprising the steps of locating said screen belt in at least partially overlapping relationship to said drum and advancing said screen belt at a speed to prevent a substantial translatory movement between said screen belt and said drum.
67. A method as defined in claim 60, comprising the step of carding the individual fibers of said fibrous starting material in a machine direction prior to passing said fibrous starting material between said coacting opposed fluid streams.
68. A method as defined in claim 60, comprising the step of applying a binder to said fibers for effecting a bond therebetween.
69 . A method as defined in claim 60, wherein the fibers of said fibrous starting material are selected from the group consisting of polyester, rayon, cotton, bico, polypropylene, nylon, acrylic and mixtures thereof.
70. A method as defined in claim 68, wherein said binder is selected from the group consisting of vinyl ethylene, vinyl chloride, vinyl acetate, polyvinyl alcohol, acrylic, polyvinyl acetate, carboxilated polystyrene, rubber, polyethylene emulsion and mixtures thereof .
71. A method as defined in claim 60, comprising the step of incorporating into at least one of said coacting opposed fluid streams a certain substance for conditioning said nonwoven fabric, whereby the stream constitutes a vehicle for applying said substance to said fibers.
72. A method as defined in claim 60, comprising the step of controlling the degree of fiber entanglement in the nonwoven fabric by controlling the velocity of said coacting opposed fluid streams.
73. A method as defined in claim 72, comprising the steps of providing a pair of manifolds with respective jet means to create said coacting opposed fluid streams, and maintaining a fluid supply pressure in each manifold in the range from 0 to approximately 220 psi.
74. A method as defined in claim 66, comprising the steps of providing a pair of manifolds with respective jet means to create said coacting opposed fluid streams, locating one of said manifolds within said drum and the other of said manifolds outside of said drum with the jet means of the manifolds in a face-to-face relationship, and controlling the fluid supply pressure in each manifold in order to control the degree of fiber entanglement in the nonwoven fabric.
75. A method as defined in claim 74, comprising the step of maintaining a fluid supply pressure in each manifold within the range from 0 to approximately 220 psi.
76. A method as defined in claim 74, comprising the step of maintaining approximately the same fluid supply pressure in each manifold.
77. A method as defined in claim 74, comprising the step of establishing a fluid supply pressure differential between said manifolds.
78. A method as defined in claim 77, comprising the step of establishing a higher fluid supply pressure in the manifold located within said drum.
79. A method as defined in claim 77, comprising the step of establishing a higher fluid supply pressure in the manifold located outside said drum.
80. A method for fluid formation of a unitary nonwoven fabric, comprising the steps of:
- providing a fibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces;
- subjecting said fibrous starting material to coacting first and second opposed fluid streams while supporting the material between an apertured member having a predetermined pattern of fluid passages therethrough, and a foraminous fluid permeable member, said first fluid stream acting through said apertured member so as to tend to form a pattern of holes in said fibrous starting material corresponding to said predetermined pattern of fluid passages, said second fluid stream acting through said foraminous member, the force of said second fluid stream relative to said first fluid stream being maintained so that said second fluid stream tends to close said holes formed by said first fluid stream by packing a portion of said fibers into said holes, whereby under the influence of fluid forces applied in opposition, the individual fibers of the material are entangled forming a reticular network of holes in which fiber packings are formed; and - controlling the intensity of the fluid forces to control the degree to which said fiber packings close said holes.
- providing a fibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces;
- subjecting said fibrous starting material to coacting first and second opposed fluid streams while supporting the material between an apertured member having a predetermined pattern of fluid passages therethrough, and a foraminous fluid permeable member, said first fluid stream acting through said apertured member so as to tend to form a pattern of holes in said fibrous starting material corresponding to said predetermined pattern of fluid passages, said second fluid stream acting through said foraminous member, the force of said second fluid stream relative to said first fluid stream being maintained so that said second fluid stream tends to close said holes formed by said first fluid stream by packing a portion of said fibers into said holes, whereby under the influence of fluid forces applied in opposition, the individual fibers of the material are entangled forming a reticular network of holes in which fiber packings are formed; and - controlling the intensity of the fluid forces to control the degree to which said fiber packings close said holes.
81. A method as defined in claim 80, comprising the step of controlling the velocity of said fluid streams to control the intensity of said fluid forces.
82. A method as defined in claim 81, comprising the step of establishing a velocity differential between fluid streams.
83. A method as defined in claim 81, comprising the step of producing fluid streams having approximately the same velocity.
84. A method for fluid formation of a unitary nonwoven fabric, comprising the steps of:
- providing a fibrous starting material whose individual fibers are capable of movement under the influence of applied fluid forces;
- confining said fibrous starting material between first and second fluid permeable members forming a supporting structure, said first member having a plurality of apertures forming a pattern;
- passing said fibrous starting material confined between said first and second members through a fluid treatment station comprising opposed first and second coacting fluid streams in a staggered relationship producing respective fluid forces which are applied in opposition through said supporting structure, said first fluid stream acting through said apertured member, thereby tending to form a pattern of holes corresponding to said pattern of apertures, said second fluid stream applied in opposition to said first fluid stream, thereby tending to close said holes formed by said first fluid stream by packing a portion of said fibers into said holes, whereby a progressive dual-sided fiber entangling of said fibrous starting material occurs so as to form the nonwoven fabric having a first side in which a pattern of holes are disposed and a second side in which a protuberant fiber packing closes each of said holes.
- providing a fibrous starting material whose individual fibers are capable of movement under the influence of applied fluid forces;
- confining said fibrous starting material between first and second fluid permeable members forming a supporting structure, said first member having a plurality of apertures forming a pattern;
- passing said fibrous starting material confined between said first and second members through a fluid treatment station comprising opposed first and second coacting fluid streams in a staggered relationship producing respective fluid forces which are applied in opposition through said supporting structure, said first fluid stream acting through said apertured member, thereby tending to form a pattern of holes corresponding to said pattern of apertures, said second fluid stream applied in opposition to said first fluid stream, thereby tending to close said holes formed by said first fluid stream by packing a portion of said fibers into said holes, whereby a progressive dual-sided fiber entangling of said fibrous starting material occurs so as to form the nonwoven fabric having a first side in which a pattern of holes are disposed and a second side in which a protuberant fiber packing closes each of said holes.
85. A method for fluid formation of a tri-dimensional unitary nonwoven fabric, comprising the steps of:
- providing a fibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces;
- subjecting said fibrous starting material to a plurality of coacting first and second opposed fluid streams while confining the material between spaced apart fluid permeable members, whereby under the influence of fluid forces applied in opposition the individual fibers of the material are entangled forming a reticular network defining a predetermined pattern of holes formed by said first fluid stream, each hole extending transversely to the plane of the fabric and containing a protuberant fiber packing formed by said second stream and closing said holes; and - controlling the relative intensity of said fluid forces of said first and second fluid streams to control the fiber distribution provide of said network in a transverse direction to the plane of the nonwoven fabric.
- providing a fibrous starting material whose individual fibers are capable of movement relatively to one another under the influence of applied fluid forces;
- subjecting said fibrous starting material to a plurality of coacting first and second opposed fluid streams while confining the material between spaced apart fluid permeable members, whereby under the influence of fluid forces applied in opposition the individual fibers of the material are entangled forming a reticular network defining a predetermined pattern of holes formed by said first fluid stream, each hole extending transversely to the plane of the fabric and containing a protuberant fiber packing formed by said second stream and closing said holes; and - controlling the relative intensity of said fluid forces of said first and second fluid streams to control the fiber distribution provide of said network in a transverse direction to the plane of the nonwoven fabric.
86. A method as defined in claim 85, comprising the step of increasing the velocity of one fluid stream relatively to the velocity of the other fluid stream to increase the size of the protuberant fiber packings and to decrease the size of the blind holes.
87. A method as defined in claim 85, comprising the step of increasing the velocity of one fluid stream relatively to the velocity of the other fluid stream to increase the size of the blind holes and to decrease the size of the protuberant fiber packings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002022080A CA2022080C (en) | 1990-07-26 | 1990-07-26 | Low fluid pressure dual-sided fiber entanglement method, apparatus and resulting product |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002022080A CA2022080C (en) | 1990-07-26 | 1990-07-26 | Low fluid pressure dual-sided fiber entanglement method, apparatus and resulting product |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2022080A1 CA2022080A1 (en) | 1992-01-27 |
| CA2022080C true CA2022080C (en) | 1996-12-24 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002022080A Expired - Lifetime CA2022080C (en) | 1990-07-26 | 1990-07-26 | Low fluid pressure dual-sided fiber entanglement method, apparatus and resulting product |
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| Country | Link |
|---|---|
| CA (1) | CA2022080C (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US12232939B2 (en) * | 2018-11-30 | 2025-02-25 | Kimberly-Clark Worldwide, Inc. | Three-dimensional nonwoven materials and methods of manufacturing thereof |
| CN118979336B (en) * | 2024-10-22 | 2025-01-07 | 淄博德坤薄膜有限公司 | A composite processing technology of spunlace nonwoven fabric |
-
1990
- 1990-07-26 CA CA002022080A patent/CA2022080C/en not_active Expired - Lifetime
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| Publication number | Publication date |
|---|---|
| CA2022080A1 (en) | 1992-01-27 |
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