Process and device for producing a highly dehydrated fluff pulp, and fluff thus obtained

Abstract

The present invention relates to a process and a device for producing a highly dehydrated fluff pulp, which passes through two to three dewatering zones in a structure which couples a DuoFormer papermaking machine to a sheet forming table. The process comprises ejecting the fibrous pulp for fluff from a headbox (2) onto a sheet forming table (11) with a horizontal lower wire (12) arranged on a discontinuous drainage shoe (13) in which a first quantity of water (100) is removed downwards through the first drainage zone (10a); and transporting the partially dehydrated fibrous pulp to the DuoFormer section (21) which forms the second drainage zone (20a), sandwiching the pulp between the lower wire and a horizontal upper wire (22) arranged under an upper discontinuous drainage shoe (23), in which a second quantity of water (200) is removed upwards, by a vacuum (50) through the upper wire (22), and downwards, by gravity, through the lower wire (12). A third discharge zone (30a) is provided, comprising a pressure roller arranged over the fluff pulp which moves along the sheet forming table (11). The final water content of the fluff pulp obtained is 6 – 11%.

Description

PROCESS AND APPARATUS FOR PRODUCING A HIGHLY DEHYDRATED FLUFF PULP, AND PULP OBTAINED FIELD OF INVENTION

[0001] The present invention is directed to a process for producing a highly dehydrated fluff pulp (HFDP). HISTORY OF THE INVENTION

[0002] Fluff pulp is also known as fluffed pulp, fluff pulp, defibrated pulp, fiberized pulp, or ground fluff pulp. It is a pulp fluffed from, typically, a web or sheet of fluff pulp. Fluff pulp, or fluff pulp, is pulp in the form of a sheet of cellulose suitably obtained for defibrating into fluff pulp.

[0003] Fluff pulp, or its undefibered pulp, is a cellulose pulp that can be hardwood, softwood, or both, obtained from wood pulping. The properties of fluff pulp can vary depending on the pulping process and the origin of the cellulose fiber. Examples of hardwood species are birch, oak, beech, maple, and eucalyptus; examples of softwood species are hemlock cedar, spruce, pine, southern pine, radiata pine, slash pine, Douglas fir, white spruce, Scandinavian pine, and Alpine lodgepole fir.

[0004] Traditionally, dewatering of fluff pulp to obtain a dry sheet of fluff pulp is carried out on a forming table.

[0005] The machine known as a duo-former is traditionally used in paper production machines. Paper is a completely different material from fluff pulp, as it contains additives such as carbonates, starch, gums, refined cellulose, dyes, etc., often amounting to 30% or more by weight of additives in the paper. Examples of commercial duo-formers are Valmet's Belbond® or Voith's duo-former.

[0006] Unlike paper, fluff pulp is used in a shredded form (thus forming a fluff pulp) in the manufacture of diapers and sanitary napkins.

[0007] Traditionally, it is believed that using a vacuum to dehydrate the upper surface of the fibrous pulp to fluff during the formation of the fluff pulp web would result in the formation of a dry, compact surface, which would prevent further removal of water from the body of the web formed by the sludge, trapping the water within the thick web, which would result in a heterogeneous water content throughout the formed fluff pulp sheet, especially for fluff pulp sheets with higher grammages or thicknesses.

[0008] Uneven drying then leads to problems such as delamination of the formed fluff pulp sheet, the formation of agglomerates after defibration of the fluff pulp sheet, a reduction in the defibration percentage of the fluff pulp, a decrease in the integrity of the defibrated fibers—which is represented by a reduced rupture rate in the fluff mat formed from the defibrated fibers—and a reduction in the specific absorption capacity of the mat once already formed in absorbent core constructions. These problems are exacerbated when using hardwoods in the fluff pulp, which have shorter fibers.

[0009] Additionally, a difference in roughness is noted on the surfaces of both sides of the sheet formed on the dewatering wire or felt, caused by the one-sided drainage typical of Fourdrinier machines. This can lead to even more uneven and complicated defibration. BRIEF DESCRIPTION OF THE INVENTION

[0010] An object of this invention is a process for producing a highly dehydrated fluff pulp (HDFP), comprising:

[0011] - ejecting the fibrous fluff pulp paste (PFPF) from an inlet box (2) onto a sheet forming table (11) and

[0012] - depositing the fibrous fluff pulp paste (PFPF) on a substantially horizontal lower wire (12) arranged on a substantially horizontal discontinuous discharge shoe (13) on a substantially horizontal sheet forming table (11)

[0013] wherein a first quantity of water (100) is removed below the fibrous pulp-to-fluff paste (PFPF) through the lower wire (12) during passage of the fibrous pulp-to-fluff paste (PFPF) through the first dewatering zone (10a);

[0014] - transporting the partially dewatered fluff pulp fibrous paste (LPFPD) formed on the lower wire (12) in a papermaking machine to a Duo-section Former (20) formed by a Duo-Former papermaking machine (21) and the sheet forming table (11), sandwiching the partially dehydrated fibrous fluff pulp (LPFPD) between the lower wire (12) and an upper wire (22)

[0015] the upper wire (22) is a substantially horizontal upper wire, arranged under

[0016] a substantially horizontal discontinuous dewatering top shoe (23)

[0017] the lower and upper strands (12, 22) defining between them a second dewatering zone (20a) for further dewatering the partially dewatered fluff pulp fibrous paste (LPFPD), forming a highly dewatered fluff pulp (PFAD),

[0018] the second drainage zone (20a) arranged downstream in relation to the first drainage zone (10a);

[0019] in which the partially dehydrated fluff pulp (PDFP) fibrous paste sandwiched between the lower and upper strands (12, 22) is conveyed

[0020] into the second outflow zone (20a)

[0021] in such a way that, during movement of the wires (12, 22), along the second drainage zone (20a);

[0022] - a second quantity of water (200) is removed upwards from the partially dewatered fluff pulp (LPFPD) fibrous paste via the upper wire (22) and downwards via the lower wire (12) during transport of the partially dewatered fluff pulp (LPFPD) fibrous paste along the second dewatering zone (20a);

[0023] the portion of water removed upwards is removed by a vacuum (50) through the upper wire (22) during movement of the wires (12, 22) along the upper shoe (23);

[0024] the upper wire (22) is connected to a vacuum source (50) so that water removed upwards is removed upwards through an upper wire (22) into an inverted box (56);

[0025] collecting a portion of the upwardly removed water through a vacuum opening (54) arranged in the Duo-Former papermaking machine (21) opposite the upper wire (22) and the discontinuous upper dewatering shoe (23);

[0026] and the portion of water removed downwards is removed by gravity through the lower wire (12) during movement of the wires (12, 22) along the lower shoe (13);

[0027] - move the threads (12, 22), forming and releasing the highly dehydrated fluff pulp (PFAD) to obtain a highly dehydrated fluff pulp (PFAD) with a water content of 6 - 11%.

[0028] Another object of the present invention is a dewatering system for dewatering the fibrous pulp paste for fluff (PFPF), the system comprising:

[0029] a sheet forming table (11);

[0030] a Duo-Former papermaking machine (21);

[0031] the Duo-Former papermaking machine (21) forming a second drain zone (20a) together with the sheet forming table (11);

[0032] superimposed on the sheet forming table (11);

[0033] in which

[0034] the first drain zone (10a) removes a first quantity of water (100) downwards, and

[0035] the second drainage zone (20a), is downstream in relation to the first drainage zone (20a);

[0036] the second drain zone removes a second quantity of water (200) downwards by gravity and upwards by vacuum.

[0037] Another object of the present invention is an apparatus for draining a pulp-to-fluff sludge (PFPF) comprising

[0038] a sheet forming table (11);

[0039] a Duo-Former papermaking machine (21);

[0040] the sheet forming table (11) comprising a first drain zone (10a) and a second drain zone (20a);

[0041] the Duo-Former papermaking machine (21) arranged on the sheet forming table (11) in the second drain zone (20a);

[0042] the Duo-Former papermaking machine (21) comprising a vacuum opening (54) wherein the vacuum opening (54) upwardly removes water from the fibrous fluff pulp (PFPF) by directing the removed water upwardly into an inverted box (56). FIGURES

[0043] Figure 1 is a perspective view of the process of the present invention.

[0044] Figure 2 is a view of the first discharge zone of the present invention.

[0045] Figure 3 is a close-up view of the discharge zone of the present invention.

[0046] Figure 4 is a close-up view of the first discharge zone of the present invention.

[0047] Figure 5 is a view of the second discharge zone of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0048] The present invention is directed to a process for producing a highly dehydrated fluff pulp (HDF) and a fluff pulp thus obtained.

[0049] The fluff pulp according to the present invention can be used in absorbent articles and sanitary products where fluff pulp is typically used in the formation of absorbent cores in infant diapers, incontinence products and feminine sanitary napkins.

[0050] Fluff pulp sheet defibration can be performed using hammer mills, saw mills, and / or pin grinders. A traditional method involves a series of saws, pins, or small hammers, for example, rotating at high speed, separating the fluff pulp sheet into loose individual fibers, thus forming fluff pulp. The fluff pulp fibers are then conveyed to the absorbent core forming system. Undesirable clumps or knots can form due to poor defibration of the fluff pulp sheet.

[0051] Typically, the fluff pulp sheet, once defibrated (i.e., formed into defibrated fluff pulp), is fed onto a forming wheel with receiving pockets that form an absorbent fluff pulp core, thereby applying some compression to the fluff pulp deposited therein. Alternatively, a defibrated fluff pulp web is placed on a moving belt, such as a moving coarse screen or a moving felt, and vacuum-assisted onto a lower forming screen, forming a fluff pulp web that can be cut and sandwiched between a nonwoven fabric and a plastic or polymeric sheet liner, thus forming an absorbent core for an infant diaper. In both cases, superabsorbent polymers (SAPs) can be introduced into the fluff pulp during the formation of the absorbent core, prior to sandwiching. Such products can be produced by methods known in the art.For example, the absorbent core with the fluff pulp can be combined with superabsorbent polymers (SAP) such as starch-acrylonitrile copolymer, hydrolyzed starch-acrylonitrile copolymer, acrylic acid (co)polymer, acrylamide (co)polymer, polyvinyl alcohol, polyacrylate / polyacrylamide copolymers, polyacrylic acid (co)polymers, sodium polyacrylate, ethylene maleic anhydride copolymer, cross-linked carboxymethyl cellulose, polyvinyl alcohol copolymer, polyethylene oxide, cross-linked polyethylene oxide, and polyacrylonitrile starch graft copolymer, salts thereof, and combination thereof.

[0052] The use of fluff cellulose pulp in hygienic articles or sanitary napkins imposes a need for hypoallergenic characteristics to the fluff pulp, which is observed by the use of little or no amount of fillers, sizing agents, dyes or pigments or any other compound other than cellulose fiber.

[0053] Defibrated fluff pulps, or fluff pulps, can be produced on a papermaking machine such as a Fourdrinier machine or any other suitable papermaking machine known in the art, and methodologies for producing fluff pulps on various papermaking machines are well known in the art.Typically, a fibrous fluff pulp slurry (FFP) may have a relatively low consistency of water pulp fiber slurry, such as about 1% by weight, and the fibrous fluff pulp slurry (FFP) is uniformly ejected from an exit box onto a forming table having a porous forming belt or an endless forming wire that moves in a loop, wherein water from the fibrous fluff pulp slurry (FFP) is gradually drained downward through tiny openings in the forming wire or porous belt by gravity or optionally with the aid of vacuum, until a warp web of pulp fibers is formed on the forming wire or forming belt.

[0054] Typically, the still-wet fiber web (a dewatered fluff pulp) is transferred from the forming wire or forming belt to a wet press, which typically features a pressure roller that presses the still-wet fiber web (a dewatered fluff pulp), further reducing its moisture content. The web then undergoes a downstream drying section to remove most, most, or substantially all, of the remaining moisture from the forming sheet and further consolidate the fibers into the web. After drying, the dried web, or fluff pulp, can be wound onto a roll to form a fluff pulp roll, or it can be cut into sheets and stacked to form a fluff pulp bale.

[0055] The process for producing highly dehydrated fluff pulp (HDFP) obtained by the present invention provides a fluff pulp with homogeneous dryness and also homogeneous specific volume with specific volume, unlike the art that presents only the forming table.

[0056] Thus, an object of the present invention is a process for producing a highly dehydrated fluff pulp (HFDP), comprising:

[0057] - ejecting the fibrous fluff pulp paste (PFPF) from an inlet box (2) onto a sheet forming table (11) and

[0058] - depositing the fibrous fluff pulp paste (PFPF) on a substantially horizontal lower wire (12) arranged on a substantially horizontal discontinuous discharge shoe (13) on a substantially horizontal sheet forming table (11)

[0059] wherein a first quantity of water (100) is removed below the fibrous pulp-to-fluff paste (PFPF) through the lower wire (12) during passage of the fibrous pulp-to-fluff paste (PFPF) through the first dewatering zone (10a);

[0060] - conveying the partially dewatered fluff pulp fibrous paste (LPFPD) formed on the lower wire (12) in a papermaking machine to a Duo-Former section (20) formed by a Duo-Former papermaking machine (21) and the sheet forming table (11), sandwiching the partially dewatered fluff pulp fibrous paste (LPFPD) between the lower wire (12) and an upper wire (22)

[0061] the upper wire (22) is a substantially horizontal upper wire, arranged under

[0062] a substantially horizontal discontinuous dewatering top shoe (23)

[0063] the lower and upper strands (12, 22) defining between them a second dewatering zone (20a) for further dewatering the partially dewatered fluff pulp fibrous paste (LPFPD), forming a highly dewatered fluff pulp (PFAD),

[0064] the second drainage zone (20a) arranged downstream in relation to the first drainage zone (10a);

[0065] in which the partially dehydrated fluff pulp (PDFP) fibrous paste sandwiched between the lower and upper strands (12, 22) is conveyed

[0066] into the second outflow zone (20a)

[0067] in such a way that, during movement of the wires (12, 22), along the second drainage zone (20a);

[0068] - a second quantity of water (200) is removed upwards from the partially dewatered fluff pulp (LPFPD) fibrous paste via the upper wire (22) and downwards via the lower wire (12) during transport of the partially dewatered fluff pulp (LPFPD) fibrous paste along the second dewatering zone (20a);

[0069] the portion of water removed upwards is removed by a vacuum (50) through the upper wire (22) during movement of the wires (12, 22) along the upper shoe (23);

[0070] the upper wire (22) is connected to a vacuum source (50) so that water removed upwards is removed upwards through an upper wire (22) into an inverted box (56);

[0071] collecting a portion of the upwardly removed water through a vacuum opening (54) arranged in the Duo-Former papermaking machine (21) opposite the upper wire (22) and the discontinuous upper dewatering shoe (23);

[0072] and the portion of water removed downwards is removed by gravity through the lower wire (12) during movement of the wires (12, 22) along the lower shoe (13);

[0073] - move the threads (12, 22), forming and releasing the highly dehydrated fluff pulp (PFAD) to obtain a highly dehydrated fluff pulp (PFAD) with a water content of 6 - 1 1%.

[0074] Figure i illustrates the coupling of the Duo-Former papermaking machine (21) onto the sheet forming table (11) which can be achieved by superimposing the sheet forming table (11) onto, and aligned with, the sheet forming table (11).

[0075] The sheet forming table (11) of the process of the process of producing a highly dewatered fluff pulp (HDFP) may further comprise a third dewatering zone (30a). The third dewatering zone (30a) may comprise at least one pressure roller disposed on the highly dewatered fluff pulp (HDFP) moving along the sheet forming table (11), and the at least one pressure roller presses the highly dewatered fluff pulp (HDFP) and removes water from the highly dewatered fluff pulp (HDFP) through the lower wire (12) disposed on the sheet forming table (11), thereby forming a sheet of fluff pulp (HDFP).

[0076] The fibrous fluff pulp (PFPF) from the highly dehydrated fluff pulp (PFAD) production process may be ejected from an inlet box (2), the fibrous fluff pulp (PFPF) having a consistency of 0.5-2%.

[0077] The fibrous fluff pulp (PFPF) from the highly dehydrated fluff pulp (PFAD) production process can be transported downstream at an average speed of 60 m / min.

[0078] The lower wire (12) from the highly dehydrated fluff pulp (HDFP) production process may be looped on the sheet forming table (11), and the upper wire (22) may be looped on the Duo-Former papermaking machine (21).

[0079] The process may further comprise a vacuum opening (54) which may be positioned immediately above or in contact with the partially dewatered fluff pulp (LPFPD) fibrous slurry in the second dewatering zone (20a). The vacuum opening (54) may provide a vacuum (50) applied to the partially dewatered fluff pulp (LPFPD) fibrous slurry which may be 0 - 6 mCa. The process further comprises an upper wire (22) which may move in the same direction and at the same speed as the lower wire (12).

[0080] A sheet of fluff pulp (FPF) is provided by the process, object of the present invention, presenting 600-800 g / m 2 , with a specific volume of at least 0.6 - 0.8 g / cm 2 , a thickness of 800 - 1000 micrometers and a width of 3-4 m, with a preferred grammage of 650-750 cm 2 .

[0081] When defibred, the fluff pulp sheet (FPF) obtained by the present invention produces fluff pulp with a knot percentage of less than 9%, typically with a defibration energy of less than 45 kWh / t. Knots are agglomerations of fibers and pulp pieces from the fluff pulp sheet that were not completely fragmented during the defibration process. Knots are defined herein as the fraction of the defibred fluff pulp that is retained on an ASTM 12 mesh screen. The knot percentage is a measure of the knots retained on the screen compared to the original amount of pulp to be defibred. Defibration energy is typically the amount of energy in kilojoules required to defiberize one kilogram of pulp in dry sheet form in a process of comminuting a dry pulp sheet into individual fibers.

[0082] Partially dewatered fluff pulp (PDFP) fibrous slurry is fed from the first dewatering zone (20a) to a second dewatering zone (20a) in the process of producing highly dewatered fluff pulp (HDFP) at a consistency of 1.5-3% and highly dewatered fluff pulp (HDFP) is fed from the second dewatering zone (20a) to the third dewatering zone (30a) at a consistency of 15-17%.

[0083] Fluff pulp sheet (FPF) may be from Bleached Hardwood Kraft Pulp (BEKP) fluff pulp sheet (FPF).

[0084] After drying, the formed fluff pulp sheet (FPF) may be further wound into a roll, thus forming a fluff pulp roll, or it may be cut into sheets and stacked, to form a bale of fluff pulp. For example, the fluff pulp sheet (FPF) may preferably be wound into a roll (60).

[0085] Another object of the present invention is to provide a dewatering system for dewatering a fibrous fluff pulp paste (PFPF), the system comprising:

[0086] a sheet forming table (11); comprising a first drain zone (10a) and a second drain zone (20a)

[0087] a sheet forming table (1 1 );

[0088] a Duo-Former papermaking machine (21);

[0089] the Duo-Former papermaking machine (21) forming a second drain zone (20a) together with the sheet forming table (11);

[0090] superimposed on the sheet forming table (11);

[0091] in which

[0092] the first drain zone (10a) removes a first quantity of water (100) downwards, and

[0093] the second drainage zone (20a), is downstream in relation to the first drainage zone (20a);

[0094] the second drain zone removes a second quantity of water (200) downwards by gravity and upwards by vacuum.

[0095] Another object of the present invention is an apparatus for draining a fibrous fluff pulp (PFPF) slurry comprising

[0096] a sheet forming table (11);

[0097] a Duo-Former papermaking machine (21);

[0098] the sheet forming table (11) comprising a first drain zone (10a) and a second drain zone (20a);

[0099] the Duo-Former papermaking machine (21) arranged on the sheet forming table (11) in the second drain zone (20a);

[0100] the Duo-Former papermaking machine (21) comprising a vacuum opening (54) wherein the vacuum opening (54) upwardly removes water from the fibrous fluff pulp (FFPF) by directing the removed water upwardly into an inverted box (56).

[0101] The process, system, or apparatus of the present invention provides improved drying / draining rate of the fibrous fluff pulp (FPS) on the sheeting table (11). For example, the dewatering process that utilizes only the sheeting table (11) to achieve a dry fluff pulp (FPF) sheet with, on average, 7% water, can utilize a sheeting table (11) up to 25 meters long (state of the art). With the process and system of the present invention, a reduction in the typical length of the sheeting table (11) can be achieved. Otherwise, production can also be increased. For example, coupling the Duo-Former papermaking machine (21) to the sheeting table (11), with the Duo-Former (21) superimposed and aligned above the sheeting table (11), which forms the dewatering process, system, and apparatus of the present invention, results in not only no negative impact on the The quality of the fluff pulp was also improved, even when operating with shortened tables. The operation of the art, using only the forming table (e.g., an Andritz forming table), results in average production rates of 57.1 m / min. The process, system, and apparatus of the present invention resulted in average production rates of 58.3 m / min. Thus, the process, system, and apparatus of the present invention allow an increase in the dewatering speed by 1.5 m / min, with a direct overall impact on the production rate equivalent to 2.7% of annual production.

[0102] Furthermore, it is believed that the Duo-Former papermaking machine (21), coupled to the sheet forming table (11), substantially removes the water intrinsic to the cellulose fiber. Intrinsic water is the water present within the cellulose fibers, and is not as easily removed as extrinsic water, and can vary greatly depending on the fiber's origin. Using the object of the present invention, extrinsic water is also removed, providing a shorter dewatering operation or, alternatively, a fluff pulp with a lower water content or, alternatively, a higher production, all three factors potentially occurring simultaneously. The water content obtained using only the sheet forming table (11) in the production of a fluff pulp results in an average water content of 7.7% by weight. The process, system and apparatus of the present invention results in an average water content of 7.32% w / w, with a 5.6% reduction in water content in the fluff pulp.

[0103] The fluff pulp sheet obtained in the present invention preferably has 600-800 g / m 2 For example, the characteristics of fluff pulp are determined by parameters of the fluff pulp sheet forming machine, such as consistency, screen exit speed control, headbox temperature, headbox ejected flow, and other operations, such as the application of steam distributed along the fluff pulp forming table and the fluff pulp fibrous pulp web; the use of drying cylinders; and other parameters such as—unlike conventional cellulose pulp—the use of air currents for drying. These state-of-the-art operations result in a fluff pulp sheet that traditionally achieves 85–95% defibration and a breaking strength of 500–950 kPa.

[0104] A reduced breaking strength leads, for example, among other problems, to the breakage of the absorbent core of diapers and sanitary napkins. Absorbent core breakage is detrimental to the proper functioning of infant diapers, leading to leaks and requiring replacement, reducing the lifespan of the sanitary napkin.

[0105] Using the process, system, and apparatus of the present invention, the high shredding rate is maintained despite the shortening of the forming table used, for example. For the fluff pulp (FPF) sheet obtained in the present invention, the shredding rate typically ranges from 85-95%.

[0106] Similarly, the burst rate is also maintained safely, even though the fluff pulp sheet (FPF) of the present invention is obtained with a shorter dewatering length. For example, the fluff pulp of the present invention has a burst rate ranging from 600 to 800 kPa.

[0107] Furthermore, the fluff pulp sheet (FPF) does not delaminate or become brittle. Water removal, or dewatering, is uniform throughout the body of the partially dewatered fluff pulp (PDFL) fibrous pulp, resulting in highly dewatered fluff pulp (HDFL) and, consequently, a uniformly dewatered fluff pulp sheet (FPF) with a uniform dry water content not only on the surface but also throughout the body.

[0108] Likewise, the present invention further provides a reduced burst rate for the obtained fluff pulp sheet (FPF). The operation of the art, as used, results in a fluff pulp with a burst rate of 726.3 kPa, and the process, system, and apparatus of the present invention resulted in a fluff pulp sheet (FPF) with a burst rate of 705.02 kPa. The defibration of the fluff pulp sheet (FPF) is not affected, where the operation of the art, with only the sheet forming table (11), typically produces a fluff pulp with a defibration rate of 96.7%, and the process, system, and apparatus of the present invention produces a fluff pulp sheet (FPF) with a defibration rate of 95.9%, with a statistically significant difference. The specific absorption capacity of the fluff pulp from the operation of the art, with only the sheet forming table, is 1.33 s / g, and with the process, system and apparatus of the present invention is 1.32 s / g, with a maximum of 1.5 s / g.The grammage obtained is further increased by 702.2 g / m. 2 to 706.6 g / m 2 and with a reduced thickness from 944.93 mm to 937.4 mm, which translates into more compact rolls for transport

Claims

CLAIMS 1. Process for producing highly dehydrated fluff pulp (HFDP), characterized by comprising: - ejecting the fibrous fluff pulp paste (PFPF) from an inlet box (2) onto a sheet forming table (11) and - depositing the fibrous fluff pulp paste (PFPF) on a substantially horizontal lower wire (12) arranged on a substantially horizontal discontinuous dewatering shoe (13) on a substantially horizontal sheet forming table (11) wherein a first quantity of water (100) is removed downwards from the fibrous fluff pulp paste (PFPF) via the lower wire (12) during passage of the fibrous fluff pulp paste (PFPF) through the first dewatering zone (10a); - conveying the partially dewatered fluff pulp fibrous slurry (LPFPD) formed on the lower wire (12) in a papermaking machine to a Duo-Former section (20) formed by a Duo-Former papermaking machine (21) and the sheet forming table (11), sandwiching the partially dewatered fluff pulp fibrous slurry (LPFPD) between the lower wire (12) and an upper wire (22), the upper wire (22) being a substantially horizontal upper wire arranged under a substantially horizontal discontinuous dewatering upper shoe (23), the lower and upper wires (12, 22) defining therebetween a second dewatering zone (20a) for further dewatering the partially dewatered fluff pulp fibrous slurry (LPFPD), forming a highly dewatered fluff pulp (PFAD), the second dewatering zone (20a) arranged to downstream in relation to the first outflow zone (10a);wherein the partially dewatered fluff pulp (PDFP) fibrous paste sandwiched between the lower and upper strands (12, 22) is conveyed into the second discharge zone (20a) in such a manner that, during movement of the strands (12, 22), along the second discharge zone (20a); - a second quantity of water (200) is removed upwards from the partially dehydrated fluff pulp (LPFPD) fibrous paste through the upper wire (22) and downwards, through the lower wire (12) during transportation of the partially dewatered fibrous fluff pulp (PLFPD) along the second dewatering zone (20a); the portion of water removed upward is removed by a vacuum (50) through the upper wire (22) during movement of the wires (12, 22) along the upper shoe (23); the upper wire (22) is connected to a vacuum source (50) such that the water removed upward is removed upward through an upper wire (22) into an inverted box (56); collecting a portion of the water removed upward by a vacuum opening (54) disposed in the Duo-Former papermaking machine (21) opposite the upper wire (22) and the discontinuous upper dewatering shoe (23); and the portion of water removed downwards is removed by gravity through the lower wire (12) during movement of the wires (12, 22) along the lower shoe (13); - moving the threads (12, 22), forming and releasing the highly dehydrated fluff pulp (HDF) to obtain a highly dehydrated fluff pulp (HDF) with a water content of 6 - 11%.

2. Process, according to claim 1, characterized by the sheet forming table (11) further comprising a third drain zone (30a).

3. Process, according to claim 1, characterized by the third dewatering zone (30a) comprising at least one pressure roller arranged on the highly dehydrated fluff pulp (PFAD) that moves along the sheet forming table (11), the at least one pressure roller pressing the highly dehydrated fluff pulp (PFAD) that moves along the sheet forming table (11) and removing water from the highly dehydrated fluff pulp (PFAD) through the lower wire (12), arranged on the sheet forming table (11), forming a sheet of fluff pulp (FPF).

4. Process according to claim 1, characterized in that the fibrous fluff pulp paste (PFPF) is ejected from an inlet box (2) with the fibrous fluff pulp paste (PFPF) having a consistency of 0.5-2%.

5. Process according to claim 1, characterized in that the fibrous fluff pulp paste (PFPF) is transported downstream at an average speed of 60 m / min.

6. Process according to claim 1, characterized in that the lower wire (12) is looped on the sheet forming table (11) and the upper wire (22) is looped on the Duo-Former papermaking machine (21).

7. Process according to claim 1, characterized in that the vacuum (50) is 2 - 6 mCa.

8. The process of claim 1, wherein the vacuum opening (54) is positioned immediately above the partially dewatered fluff pulp (PDFL) fibrous paste in the second dewatering zone (20a).

9. Process according to claim 1, characterized in that the upper wire (22) moves in the same direction and at the same speed as the lower wire (12).

10. Process, according to claim 1, characterized in that the fluff pulp sheet (FPF) has a grammage of 600-800 g / m 2 .

11. Process, according to claim 1, characterized in that the fluff pulp sheet (FPF) comprises a specific volume of at least 0.6 - 0.8 g / cm 3 .

12. Process according to claim 1, characterized in that the fluff pulp sheet (FPF) comprises a sheet with a thickness of 800 - 1000 micrometers.

13. Process according to claim 1, characterized in that the fluff pulp sheet (FPF) comprises a sheet with a width of 3-4 m.

14. Process, according to claim 10, characterized by the fluff pulp sheet (FPF) comprising a sheet with a grammage of 670 - 760 g / m 2 .

15. Process according to claim 1, characterized in that the partially dewatered fluff pulp fibrous paste (PDFP) is fed from the first dewatering zone (20a) to the second dewatering zone (20a) at a consistency of 1.5-3%.

16. Process, according to claim 1, characterized in that the highly dehydrated fluff pulp (HFDP) is fed from the second dewatering zone (20a) to the third dewatering zone (30a) at a consistency of 15-17%.

17. Process according to claim 1, characterized by the fluff pulp sheet (FPF) comprising BEKP.

18. Process, according to claim 1, characterized in that the sheet of fluff pulp (FPF) is wound on a roll (60).

19. Fluff pulp characterized by being obtained by the process as defined in claim 1.

20. A dewatering system for dewatering a fibrous fluff pulp (PFPF) pulp, characterized in that it comprises: a sheet forming table (11); comprising a first dewatering zone (10a) and a second dewatering zone (20a) a sheet forming table (11); a Duo-Former papermaking machine (21); the Duo-Former papermaking machine (21) forming a second dewatering zone (20a) together with the sheet forming table (11); superimposed on the sheet forming table (11); wherein the first dewatering zone (10a) removes a first quantity of water (100) downwardly, and the second dewatering zone (20a) is downstream in relation to the first dewatering zone (20a); the second drain zone removes a second quantity of water (200) downwards by gravity and upwards by vacuum.

21. Apparatus for draining a fibrous fluff pulp (PFPF) slurry, comprising a sheet forming table (11); a Duo-Former papermaking machine (21); the sheet forming table (11) comprising a first dewatering zone (10a) and a second dewatering zone (20a); the Duo-Former papermaking machine (21) disposed above the sheet forming table (11) in the second dewatering zone (20a); the Duo-Former papermaking machine (21) comprising a vacuum opening (54) wherein the vacuum opening (54) upwardly removes water from the fibrous fluff pulp (PFPF), directing removed water upwardly into an inverted box (56).

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