RU2771694C2 - Paper products exhibiting high bending stiffness and strength in the transverse direction, and methods for production thereof - Google Patents

Abstract

FIELD: paper.

SUBSTANCE: group of inventions relates to a paper product and a method for production of the paper product, including: providing a forming mesh; bringing the forming mesh to rotation so that the upper surface of the forming mesh moves in the machine direction; providing a multi-layered headbox including a first and a second intake collectors and a layer outlet; introducing a first aqueous suspension of the first fibres into the first intake collector and a second aqueous suspension of the second fibres into the second intake collector; combining the flows of the first and second aqueous suspensions, forming a jet exiting through the layer outlet; directing the jet to the upper surface of the forming mesh, forming a web; bringing the forming mesh to oscillatory motion in the transverse direction relative to the machine direction, resulting in at least a significant amount of the first fibres being oriented in a direction diverging from the machine direction; and producing a paper product from the web.

EFFECT: produced paper product exhibits high bending stiffness and strength in the transverse direction.

10 cl, 14 dwg

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to paper products, and more particularly to paper products having improved flexural stiffness and transverse strength, and methods for making the same.

State of the art of the present invention

Flexural stiffness, tensile strength and compressive strength are important characteristics of many paper products, such as those used to make folding cartons, liquid packs and corrugated containers. Multilayer or multilaminate paper materials, which are generally stiffer and exhibit higher tensile and compressive strengths than the corresponding single layer products, are widely used in the manufacture of such products. In some conventional papermaking techniques, aqueous slurries of wood fibers are introduced into a multilayer headbox that produces a paper product that includes two or more layers or layers.

Each of the aqueous suspensions may contain fibers that have certain properties (such as, for example, fiber length, type of wood, recycled or untreated fibers, etc.) and/or that have been subjected to one or more types of processing (for example , refined), so that each layer or layer contains fibers having different properties, which allows the production of paper products with specialized characteristics. In addition, it is known that the formation of a paper product is improved by vibrations or vibrations of one or more components of the paper machine, such as, for example, the forming wire, on which aqueous suspensions are placed, and/or the breast roll.

However, there is still a need for paper products having increased flexural rigidity and transverse tensile and compressive strength, as well as methods for making them.

Brief description of the figures

While the description of the invention is consistent with the claims, by disclosing and expressly stating the present invention, the authors believe that the present invention will become more clear from the following description in combination with the accompanying graphic figures, in which like reference numbers designate like elements, and at the same time:

in fig. 1 is a side view of a part of a Foudrinier forming section of a paper machine with a two-layer headbox;

in fig. 2 is a side view of a portion of a Fudrinier forming section of a paper machine with a three-layer headbox;

in fig. 3 is a side view of a portion of two stacked Fudrinier forming units of a paper machine, each Fudrinier forming unit using a three-layer headbox;

in fig. 4 is a plan view of an upstream portion of a paper machine's Fudrinier forming section, including a paper machine vibrator known as a vibrating table;

in fig. 5 is a partial cross-sectional view of a chest roll incorporating one type of chest roll vibrating device;

in fig. 6 is a perspective view of a cross section of a three-ply web formed in accordance with the present invention;

in fig. 7A and 7B are perspective views of stacked boxes;

in fig. 8 is a perspective view of an exemplary final paper product;

in fig. 9 is a flow diagram illustrating an exemplary method for manufacturing a paper product;

in fig. 10 is a sectional perspective view of a two-ply web formed in accordance with the present invention;

in fig. 11 is another flow diagram illustrating an exemplary method for manufacturing a paper product;

in fig. 12 are bar graphs comparing the flexural stiffness (cross direction (CD)) of sheets containing a mixture of 25% kraft fibers and 75% old corrugated cardboard (OCC) container formed without vibration; sheets containing a mixture of 25% kraft fibers and 75% OSS, formed with vibration; laminated sheets containing 75% OSS and 25% kraft fibers, and kraft fibers form the bottom layer closest to the forming wire; and delaminated sheets containing 75% OSS and 25% kraft fibers, with OSS forming the bottom layer closest to the forming wire; and

in fig. 13 are bar graphs comparing compressive strength (cross direction) of sheets containing a mixture of 25% kraft fibers and 75% OSS, formed without vibration; sheets containing a mixture of 25% kraft fibers and 75% OSS, formed with vibration; laminated sheets containing 75% OSS and 25% kraft fibers, and kraft fibers form the bottom layer closest to the forming wire; and delaminated sheets containing 75% OSS and 25% kraft fibers, with OSS forming the bottom layer closest to the forming wire.

Detailed disclosure of the present invention

In the following detailed description of the preferred embodiments, reference is made to the accompanying figures, which form part of it, and which provide, by way of illustration and not as limitation, specific preferred embodiments in which the present invention may be practiced. It should be understood that other embodiments can be used and that changes can be made without departing from the idea and going beyond the scope of the present invention.

According to one embodiment of the subject matter of the invention as claimed herein, a paper product and method for making the same is provided, wherein the forming wire oscillates during formation of a web comprised of a plurality of layers or layers such that it causes a plurality of first fibers adjacent to the forming wire to , navigate in a direction that deviates from the machine direction. The terms "machine direction" or "MD" may be used herein to refer to the direction of material flow in a manufacturing process. In addition, the relative position and movement of the material can be described as corresponding to the machine direction in the manufacturing process from the upstream process position to the downstream process position. The terms "cross-machine direction", "cross-machine direction", or "CD" may be used herein to refer to a direction that is generally perpendicular or transverse to the machine direction, including in the plane of the forming fabric and in the plane of the sheet, which is in the process of being molded.

One advantage of the subject matter of the invention claimed herein is that the paper product exhibits improved lateral compression strength compared to paper products made without oscillatory motion. Another advantage of the subject matter claimed herein is that the paper product exhibits increased transverse bending stiffness compared to paper products made without oscillatory motion. A further advantage is that the composition of each formation or layer can be individually adjusted to achieve the desired properties. Additional benefits are presented in this document.

According to one embodiment of the subject matter of the invention claimed herein, a paper product is provided that includes first fibers and second fibers, wherein:

the first fibers have a shorter average length than the average length of the second fibers;

most of the fibers located near one outer surface constitute the first fibers, and most of the fibers located near the opposite outer surface constitute the second fibers; and

the first fibers are deviated from the direction in which most of the second fibers are oriented.

In one embodiment, most of the second fibers are oriented substantially in the machine direction and most of the first fibers are skewed toward the lateral direction.

According to another embodiment, the first fibers are deflected in a direction passing at an angle in the range between >0 and ≤90 degrees with respect to the machine direction. This range includes all intermediate values and sub-ranges, including +5, +10, +15, +20, +25, +30, +35, +40, +45, +50, +55, +60, +65 , +70, +75, +80 and +85 degrees and -5, -10, -15, -20, -25, -30, -35, -40, -45, -50, -55, -60, -65, -70, -75, -80 and -85 degrees.

According to another embodiment of the subject matter claimed herein, there is provided a paper product made by a method including:

providing a forming wire that is supported by the chest roll and at least one additional roll;

bringing the forming fabric into rotation so that the upper surface of the forming fabric moves in the machine direction;

providing a multilayer headbox including first and second intake manifolds and a layered outlet of the multilayer headbox, the first intake manifold located below the second intake manifold;

introducing a first aqueous suspension of first fibers into a first intake manifold and a second aqueous suspension of second fibers into a second intake manifold, the first fibers having a shorter average length than the average length of the second fibers;

combining the streams of the first and second aqueous suspensions in the area of the layer outlet of the multilayer headbox to form a jet exiting through the layer outlet of the multilayer headbox;

directing a jet of the combined and thus layered suspensions to the upper surface of the forming wire, and the jet of the combined suspensions forms a web on the forming wire, and at the same time, near the forming wire, the first fibers are present in a higher percentage than the second fibers;

bringing the forming wire into an oscillating motion transverse to the machine direction, thereby ensuring the orientation of at least a significant number of the first fibers in a direction that deviates from the machine direction; and

fabrication of paper products.

Although not specifically limited, according to one embodiment, at least one additional shaft includes a drive shaft, and driving the forming wire includes driving the drive shaft.

According to one embodiment, the method further includes maintaining the flows of the first and second aqueous slurries separated from each other as the first and second aqueous slurries move from the first and second inlet manifolds into the layered outlet area of the multilayer headbox.

According to one embodiment, oscillating the forming wire includes oscillating a structure in contact with the forming wire. According to another embodiment, oscillating the forming wire includes oscillating the breast roll in a direction generally parallel to the axis of the breast roll.

In one embodiment, the forming fabric oscillates causing a significant number of first fibers to orient in a direction that is between >0 and *<90 degrees with respect to the machine direction. This range includes all intermediate values and sub-ranges, including +5, +10, +15, +20, +25, +30, +35, +40, +45, +50, +55, +60, +65 , +70, +75, +80 and +85 degrees and -5, -10, -15, -20, -25, -30, -35, -40, -45, -50, -55, -60, -65, -70, -75, -80 and -85 degrees.

Although not specifically limited, in one embodiment, the paper product includes paper, and in another embodiment, the paper product includes paperboard.

According to a further embodiment of the subject matter claimed herein, a method for making a paper product is provided, the method comprising:

providing a forming wire that is supported by the chest roll and at least one additional roll;

bringing the forming fabric into rotation so that the upper surface of the forming fabric moves in the machine direction;

providing a multilayer headbox including first and second intake manifolds and a layered outlet of the multilayer headbox, the first intake manifold located below the second intake manifold;

introducing a first aqueous suspension of first fibers into a first intake manifold and a second aqueous suspension of second fibers into a second intake manifold, the first fibers having a shorter average length than the average length of the second fibers;

combining the streams of the first and second aqueous suspensions in the area of the layer outlet of the multilayer headbox to form a jet exiting through the layer outlet of the multilayer headbox;

directing a jet of the combined and thus layered suspensions to the upper surface of the forming wire, and the jet of the combined suspensions forms a web on the forming wire, and at the same time, near the forming wire, the first fibers are present in a higher percentage than the second fibers;

bringing the forming wire into an oscillating motion transverse to the machine direction, thereby ensuring the orientation of at least a significant number of the first fibers in a direction that deviates from the machine direction; and making a paper product from a web.

Although not specifically limited, according to one embodiment, at least one additional shaft includes a drive shaft, and driving the forming wire includes driving the drive shaft.

According to one embodiment, the method further includes maintaining the flows of the first and second aqueous slurries separated from each other as the first and second aqueous slurries move from the first and second inlet manifolds into the layered outlet area of the multilayer headbox.

According to one embodiment, oscillating the forming fabric includes oscillating the fibrous oriented structure in contact with the forming fabric. According to another embodiment, oscillating the forming wire includes oscillating the breast roll in a direction generally parallel to the axis of the breast roll.

According to another embodiment, the forming fabric oscillates causing a significant number of first fibers to orient in a direction that is at an angle ranging between >0 and ≤90 degrees with respect to the machine direction. This range includes all intermediate values and sub-ranges, including +5, +10, +15, +20, +25, +30, +35, +40, +45, +50, +55, +60, +65 , +70, +75, +80 and +85 degrees and -5, -10, -15, -20, -25, -30, -35, -40, -45, -50, -55, -60, -65, -70, -75, -80 and -85 degrees.

Although not specifically limited, in one embodiment, the paper product includes paper, and in another embodiment, the paper product includes paperboard.

In FIG. 1 shows a portion of a Fudrinier forming section 100 of a paper machine in accordance with the present invention, in which the Fudrinier forming section 100 includes a two-layer headbox 10, which is shown in partial cross section. In FIG. 2 shows a similar part of the Fudrinier forming section 100 of a paper machine with a three-layer headbox 50, which is shown in partial cross-section, with the corresponding parts designated by the same reference numbers. As shown in FIG. 1 and 2, the Fudrinier forming section 100 includes a forming wire 102 supported by a breast roll 104, one or more drive rolls 106, and return rolls 108 back to the breast roll 104. Although two drive rolls 106 and four return rolls 108 are illustrated, the Fudrinier forming section 100 may include any number of drive and/or return rolls 106, 108. The forming wire 102 may include an endless wire or belt and is driven by one or more drive rolls 106 such that the forming wire 102 rotates and the top surface 102A forming wire 102 moves in the machine direction represented by arrow A.

As shown in FIG. 1, a two-layer headbox 10 may include a first intake manifold 12 and a second intake manifold 14, with the first intake manifold 12 located below the second exhaust manifold 14. The first intake manifold 12 receives a first aqueous slurry 20 containing first fibers and the second intake manifold 14 enters the second aqueous suspension 22 containing the second fibers. As described herein, the second aqueous suspension 22 may have different characteristics or properties than the first aqueous suspension 20. In particular, the second fibers may have different characteristics or properties compared to the first fibers. From the first inlet manifold 12, the first aqueous slurry 20 passes into the turbulence generator 26, including the turbulence tubes 26-1 to 26-n, and then into the first inlet chamber 30 in the layered cone 40. The layered cone 40 is formed at the narrowed downstream end headbox 10. From the second inlet manifold 14, the second aqueous suspension 22 passes into the turbulence generator 28, including the turbulence pipes from 28-1 to 28-n, and then into the second inlet chamber 32 in the layered cone 40. The first and second inlet chambers 30, 32 are defined and separated from each other by a plate 34 commonly known as a lamellar plate. Separate streams of aqueous slurries 20, 22 are maintained within the headbox 10 by plate 34 until the aqueous slurries 20, 22 are combined in the (not individually numbered) layered outlet of the multilayer headbox 42 with jet definition 44. Jet 44, comprising the combined yet layered aqueous slurries 20, 22, exits the layered outlet 42 onto the top surface 102A of the forming wire 102. The layered cone 40 may optionally include a layered regulator 41 as shown in FIG. 1, which allows the size of the layer outlet 42 to be controlled, i. e. the area of the layer outlet, extending in the transverse direction (not shown; see Fig. 4) and usually in the vertical direction, indicated by the arrow V in Fig. one.

The jet 44 forms a layer of aqueous fibrous slurry 46 (also referred to as web) on the forming wire 102. Although the combination of the aqueous slurries 20, 22 to form the jet 44 causes some mixing of the aqueous slurries 20, 22, it is known that separation of the aqueous slurries 20, 22 in layers along is at least partially supported in the web 46 which is formed when the combined aqueous slurries 20, 22 are deposited on the forming wire 102. Thus, FIG. a first aqueous slurry 20; and a second layer or layer 46-2 containing primarily a second aqueous slurry 22, wherein the first fibers in the first aqueous slurry 20 present in greater percentages are located closer to the forming wire 102 than the second fibers in the second aqueous slurry. slurry 22. Thereafter, a paper product can be made from the web 46 using known methods.

As shown in FIG. 2, the three-layer headbox 50 may include a first intake manifold 52, a second intake manifold 54, and a third intake manifold 56. The first intake manifold 52 is the lowest intake manifold that is located below the second intake manifold 54. The second intake manifold 54 is located below the third intake manifold. manifold 56. The first intake manifold 52 receives the first aqueous slurry 60 containing the first fibers, the second intake manifold 54 receives the second aqueous slurry 62 containing the second fibers, and the third intake manifold 56 receives the third aqueous slurry 64 containing the third fibers. As described herein, the first, second, and third aqueous suspensions 60, 62, 64 may have different characteristics or properties from each other. From the first inlet manifold 52, the first aqueous slurry 60 passes into the turbulence generator 66, which includes turbulence tubes (not individually numbered; see Fig. 1), and then into the first inlet chamber 80 in a layered cone 90, which is formed in a narrowed downstream flow at the end of the headbox 50. From the second inlet manifold 54, the second aqueous slurry 62 passes into the turbulence generator 68, which includes turbulence tubes (not individually numbered; see Fig. 1), and then into the second inlet chamber 82 in the layered cone 90. From third inlet manifold 56, the third aqueous slurry 64 passes into a turbulence generator 70 including turbulence tubes (not individually numbered) and then into a third inlet chamber 84 in a layered cone 90. The first, second and third inlet chambers 80, 82 and 84 are defined and separated from each other by means of the first and second plates or lamellar plates 86, 88.

In addition, as shown in FIG. 2, separate streams of aqueous slurries 60, 62, 64 are maintained within the headbox 50 by plates 86, 88 until the aqueous slurries 60, 62, 64 exit through the layered outlet of the multi-layered headbox 92 in a jet 94 comprising combined yet layered aqueous slurries 60, 62, 64. Layered cone 90 may optionally include a layered regulator 91 that can be used to control the size of layered outlet 92 as described with respect to FIG. 1. Jet 94 forms a layer of aqueous fibrous slurry 96 (also referred to as web) on forming wire 102. Although the combination of aqueous slurries 60, 62, 64 to form jet 94 causes some mixing of aqueous slurries 60, 62, 64, it is known that separation of aqueous slurries 60, 62, 64 in layers is at least partially supported in web 96, which is formed when the combined aqueous slurries 60, 62, 64 are deposited on forming wire 102. Thus, web 96, which is illustrated in FIG. 2 includes a first layer or formation 96-1 containing primarily a first aqueous slurry 60, a second layer or formation 96-2 containing primarily a second aqueous slurry 62, and a third layer or formation 96-3 containing, especially the third aqueous slurry 64. Thereafter, a paper product can be made from the web 96 using known methods.

In FIG. 3 shows two Fudrinier forming sections, for example, the first Fudrinier forming section 100-1 and the second Fudrinier forming section 100-2, of a paper machine, the Fudrinier forming sections 100-1, 100-2 being stacked, and each of them includes a respective three-layer pressure box 50-1, 50-2, shown in partial cross section. Each Fudrinier forming section 100-1, 100-2 includes a respective forming wire 102-1, 102-2 supported by a chest roll 104-1, 20104-2, one or more drive rolls 106-1, 106-2 and return rolls. 108-1, 108-2 leading back to the chest shaft 104-1, 104-2. The forming wire 102-1, 102-2 may include an endless wire or belt driven by one or more drive shafts 106-1, 106-2 such that the upper surface of the forming wire 102A-1, 102A-2 moves in machine direction, which is represented by arrow A-1 in FIG. 3 for the first Fudrinier forming section 100-1 and arrow A-2 for the second Fudrinier forming section 100-2. Although the Fudrinier forming sections 100-1, 100-2 are illustrated as having two drive rolls 106-1, 106-2 and three or four return rolls 108-1, 108-2, each Fudrinier forming section 100-1, 100-2 may include any number of drive and return shafts.

Headboxes 50-1, 50-2 in FIG. 3 may be substantially similar in construction to the three-layer headbox 50 illustrated in FIG. 2 or the two-layer headbox 10 illustrated in FIG. 1. The designations of some of the components in Fig. 3 are missing to illustrate in detail other aspects of the Fudrinier forming sections 100-1, 100-2. Each three-layer headbox 50-1, 50-2 may include a first intake manifold 52-1, 52-2, a second intake manifold 54-1, 54-2, and a third intake manifold 56-1, 56-2. The first intake manifold 52-1, 52-2 is the lowest intake manifold, which is located below the corresponding second intake manifold 54-1, 54-2. The second intake manifold 54-1, 54-2 is located below the corresponding third intake manifold 56-1, 56-2. The first intake manifold 52-1, 52-2 of each headbox 50-1, 50-2 receives the first aqueous suspension 60-1, 60-2 containing the first fibers, the second intake manifold 54-1, 54-2 receives the second an aqueous slurry 62-1, 62-2 containing the second fibers, and a third aqueous slurry 64-1, 64-2 containing the third fibers enters the third intake manifold 56-1, 56-2. As described herein, the first, second and third aqueous suspensions 60-1, 60-2, 62-1, 62-2, 64-1, 64-2 may have different characteristics or properties compared to other aqueous suspensions within the respective headbox 50-1, 50-2.

From the first intake manifold 52-1, 52-2, the first aqueous slurry 60-1, 60-2 passes into the turbulence generator including turbulence tubes (not individually numbered; see FIGS. 1 and 2) and then into the first inlet chamber 80-1, 80-2 in a layered cone 90-1, 90-2, which is formed at the respective tapered downstream end of each headbox 50-1, 50-2. From the second intake manifold 54-1, 54-2, the second aqueous slurry 62-1, 62-2 passes into the turbulence generator, including turbulence tubes (not individually numbered; see Figs. 1 and 2), and then into the second inlet chamber 82-1, 82-2 in layer cone 90-1, 90-2. From the third intake manifold 56-1, 56-2, the third aqueous slurry 64-1, 64-2 passes into the turbulence generator, including turbulence tubes (not individually numbered), and then into the third inlet chamber 84-1, 84-2 in layer cone 90-1, 90-2. The first, second and third inlet chambers 80-1, 80-2, 82-1, 82-2, 84-1, 84-2 are defined and separated from each other by respective first and second plates or lamellar plates (not numbered; see Fig. 1 and 2).

In addition, as shown in FIG. 3, separate streams of aqueous slurries 60-1, 60-2, 62-1, 62-2, 64-1, 64-2 are maintained within their respective headboxes 50-1, 50-2 by first and second plates (not numbered ) until the aqueous suspensions 60-1, 60-2, 62-1, 62-2, 64-1, 64-2 exit through the layer outlet of the multilayer headbox 92-1, 92-2 in the jet 94- 1, 94-2. The jet 94-1 leaving the headbox 50-1 includes the combined and thus layered aqueous suspensions 60-1, 62-1, 64-1, and the jet 94-2 leaving the headbox 50-2 includes the combined aqueous suspensions 60-2, 62-2, 64-2. The layered cone 90-1, 90-2 may optionally include a layered regulator (not numbered; see FIGS. 1 and 2). Each jet 94-1, 94-2 forms layers of aqueous fibrous slurry 96A, 96B (also referred to as first and second webs) on a respective forming wire 102-1, 102-2. Although the combination of aqueous suspensions 60-1, 62-1, 64-1 to form jet 94-1 causes some mixing of aqueous suspensions 60-1, 62-1, 64-1, it is known that the separation of aqueous suspensions 60-1, 62- 1, 64-1 in layers is at least partially supported in the first web 96A, which is formed when the combined aqueous slurries 60-1, 62-1, 64-1 are deposited on the forming wire 102-1. Thus, the first web 96A, which is illustrated in FIG. slurry 62-1, and a third layer or formation 96A-3 containing primarily a third aqueous slurry 64-1. Similarly, the second web 96B that is formed from the jet 94-2 is illustrated as including a first layer or formation 96B-1 containing primarily a first aqueous slurry 60-2, a second layer or formation 96B-2 containing primarily , a second aqueous slurry 62-2, and a third layer or formation 96B-3 containing primarily a third aqueous slurry 64-2.

As shown in FIG. 3, the second Fudrinier forming section 100-2 is positioned so that it moves "against" the first Fudrinier forming section 100-1. The breast roll 104-2, the drive rolls 106-2, and the forming wire 102-2 of the second Fudrinier forming section 100-2 may be positioned such that the second web 96B begins to move in a direction that is reverse or opposite to that of the first. canvases 96-2. At a position downstream of the chest roll 104-2, the direction of the second web 96B is reversed such that the second web 96B moves in the same direction as the first web 96A. Thereafter, webs 96A, 96B may be combined or stacked to form a six layer web 98 as shown in FIG. 3, webs 96A, 96B may be combined or stacked such that the third layers 96B-3 of the respective webs 96A, 96B were in contact with each other, and the respective first layers 96A-1, 96B-1 formed the outer surface of the six-layer web 98, as described in more detail herein. Thereafter, a paper product can be made from the web 98 using known techniques.

Although in FIG. 1-3 illustrate two-layer and three-layer headboxes 10, 50, 50-1, 50-2, it should be understood that the present invention can also be implemented using four-layer headboxes, five-layer headboxes, etc. Additional examples of multilayer headboxes that may be used are described in US Pat. Nos. 6,544,387; 6,962,646 and 7,381,295, the disclosures of which are incorporated herein by reference in their entirety.

In all embodiments, each aqueous slurry may have one or more different characteristics or properties compared to the aqueous slurry in one or more adjacent intake manifolds. In particular, each of the aqueous suspensions may contain fibers with a different average fiber length. You can use one or more technologies known in the art to obtain aqueous suspensions containing fibers with different average lengths. One or more starting or input materials used to form aqueous suspensions may contain raw materials, recycled materials, or mixtures thereof. As one example, the average length of the fibers can be at least partially controlled by selecting starting materials from one or more bales of fibers containing, for example, fibers obtained predominantly from a particular type or species of plant (eg, coniferous or deciduous). Chemically kraft pulped softwood fibers are typically the longest and strongest softwood fibers produced, which may include fibers with an average length of, for example, about 3 to 4 mm. This average length includes all intermediate values and sub-ranges, including 3.20, 3.25, 3.30, 3.35, 3.40, 3.45, 3.50, 3.55, 3.60, 3 .65, 3.70, 3.75, and 3.80 mm. Hardwood fibers are generally shorter and may include fibers with an average fiber length of, for example, about 1 to 1.2 mm. This average length includes all intermediate values and sub-ranges, including 1.05, 1.10 and 1.15 mm. Typical fiber sizes of raw materials may include, for example, the following (depending on the geographical area of origin and the method of pulping):

coniferous kraft fibers: from 2.4 to 3.6 mm;

fibers from bleached chemothermomechanical/thermomechanical (BCTM/TMR) softwood pulp: 1.45 to 2.0 mm; and

hardwood kraft fibers: 0.9 to 1.1 mm.

Average lengths quoted include all intermediate values and sub-ranges, including 2.45, 2.50, 2.55, 2.60, 2.65, 2.70, 2.75, 2.80, 2.85, 2.90, 2.95, 3.00, 3.05, 3.10, 3.15, 3.20, 3.25, 3.30, 3.35, 3.40, 3.45, 3, 50 and 3.55 for softwood kraft fibers; 1.50, 1.55, 1.60, 1.65, 1.70, 1.75, 1.80, 1.85, 1.90 and 1.95 mm for HTTM/TMP softwood fibers; and 0.95, 1.00 and 1.05 mm for hardwood kraft fibers.

As shown in FIG. 1-3, the first aqueous slurry 20, 60, 60-1, 60-2 may contain fibers having the longest average length used to form the web. The first aqueous slurry 20, 60, 60-1, 60-2 can be obtained, for example, by selecting starting materials containing mainly untreated softwood fibers, although each of the second aqueous slurry 22, 62, 62-1, 62- 2 and the third aqueous slurry 64, 64-1, 64-2 can be obtained by selecting raw materials containing mainly untreated hardwood fibers. As is known in the art, each of the first, second, and third aqueous slurries can be made using a separate wood pulp slurry (not shown) that enters each respective intake manifold from a separate feed tank (not shown).

Alternatively or in addition, fractionation may be used to classify and separate the fibers in the pulp slurry by size into a short fiber fraction ("SF") and a long fiber fraction ("LF"). For example, fractionation can be used when the starting materials include recycled materials, such as old corrugated cardboard containers, newspapers, magazines, etc., and/or materials with a higher degree of fiber length variability. Recycled materials may include fibers having a length of, for example, 0.9 to 2.7 mm. This average length includes all intermediate values and subranges, including 0.95, 1.00, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1 .40, 1.45, 1.50, 1.55, 1.60, 1.65, 1.70, 1.75, 1.80, 1.85, 1.90, 1.95, 2.00 , 2.05, 2.10, 2.15, 2.20, 2.25, 2.30, 2.35, 2.40, 2.45, 2.50, 2.55, 2.60 and 2 .65 mm. As shown in FIG. 1-3, the first aqueous slurry 20, 60, 60-1, 60-2 may contain one or more streams containing long fibers that result from one or more fractionation stages, while each of the second aqueous slurry 22, 62, 62-1, 62-2 and the third aqueous slurry 64, 64-1, 64-2 may contain one or more streams containing short fibers that result from one or more fractionation stages. As is known in the art, each of the first, second, and third aqueous slurries can be obtained by fractionating one or more wood pulp slurries (not shown) that come from one or more feedstock tanks (not shown), the resulting streams being short fibers and long fibers enter the respective intake manifolds.

In addition, one or more additives can be used to, for example, change the amount of free fines in an aqueous suspension, increase the strength of the final paper product, and so on. The fibers may also go through one or more additional steps before or after fractionation, such as purification, dispersion and/or refining.

In this example, the first aqueous suspension 20, 60, 60-1, 60-2 in FIG. 1-3, i.e. the portion of the web 46, 96, 96A, 96B that is in contact with the upper surface 102A, 102A-1, 102A-1 of the forming wire 102, 102-1, 102-2, contains the first fibers with the first (longest) average length, and the second aqueous suspension 22, 62, 62-1, 62-2 contains second fibers with a second average length that is less than the first average length. As shown in FIG. 2 and 3, when a third intake manifold 56, 56-1, 56-2 is present, the third aqueous slurry 64, 64-1, 64-2 may comprise third fibers with a third average length. In some specific cases, the third average length may be less than the first average length. In other specific cases, the third average length may be less than the first and second average lengths. For example, the first fibers in the first aqueous slurry 20, 60, 60-1, 60-2 may include fibers that are approximately three times the length of the second and/or third fibers, such as when the first aqueous slurry 20, 60, 60- 1, 60-2 contains softwood fibers, and the second and/or third aqueous suspensions 22, 62, 62-1, 62-2, 64, 64-1, 64-2 contain hardwood fibers. In the following specific cases, according to the embodiment shown in FIG. 2, the third average length may be substantially the same or greater than the first average length as described herein.

As shown in FIG. 1 As another example, the first aqueous slurry 20 may contain fibers having an average length that is less than the average length of the fibers in the second aqueous slurry 22. The first and second aqueous slurries 20, 22 may be prepared in the manner described herein. document, which may optionally include the use of one or more additives, which is also described in this document. In this example, the first aqueous suspension 20, i. the portion of web 46 that is in contact with top surface 102A of forming wire 102 includes first fibers having a first average length, and second aqueous slurry 22 includes second fibers having a second average length that is greater than the first average length. In some instances, the second fibers in the second aqueous slurry 22 may include fibers that are many times the length of the first fibers (eg, twice as long, three times as long, etc.). As shown in FIG. 2, when a third intake manifold 56 is present, the third aqueous slurry 64 may comprise third fibers having a third average length that is greater than the first average length. In some cases, the second average length may be less than the first average length. In other cases, the second average length may be greater than or the same as the first average length and less than or the same as the third average length.

As shown in FIG. 1-3, when the aqueous slurries are combined to form the respective jets 44, 94, 94-1, 94-2 and deposited onto the forming wire 102, 102-1, 102-2, the majority of the fibers in each layer or layer of the resulting webs 46 , 96, 96A, 96B with higher predominance are oriented in the machine direction, as illustrated by the respective arrows A, A-1, A-2. The transverse vibrations of the forming wire 102, 102-1, 102-2, i. e. vibrations of the forming fabric in a direction that is transverse or substantially perpendicular to the machine direction can be used to improve the formation of the final paper product by excitation of hydrodynamic and mechanical shear forces in the web 46, 96, 96A, 96B on the forming fabric 102, 102- 1, 102-2. In particular, since the first layer 46-1, 96-1, 96A-1, 96B-1 of each web 46, 96, 96A, 96B containing mainly the first aqueous suspension 20, 60, 60-1, 60-2 containing fibers with the first (longest) average length is in contact with the forming fabric 102, 102-1, 102-2, the authors believe that the first fibers are subjected to the greatest effect of transverse shear forces.

The transverse or transverse vibrations of the forming wire 102, 102-1, 102-2 according to any of the embodiments illustrated in FIG. 1-3 can be achieved with one or more structures known in the art. As one example, as shown in FIG. 4, the fiber oriented structure including the paper machine vibrating table device 200 causes the forming wire 102 to oscillate in the direction transverse to the machine direction, i.e. causes the forming wire 102 to oscillate in the transverse direction. The paper machine vibratory table apparatus 200 may be used with a breast roll 104 and a headbox 10, which may correspond to any of the embodiments described herein, including the embodiment shown in FIG. 3 that includes two Fudrinier forming sections. The paper machine vibratory table apparatus 200 may include a plurality of T-beams 202, 204 and a side frame (not shown), with alternating T-beams attached to the side frame, such as T-beams 202 or T-beams movable with respect to the side frame in the direction indicated. arrow B, for example, T-beams 204. The paper machine vibrating table apparatus 200 is described in more detail in US Pat. No. 4,055,460, the disclosure of which is incorporated herein by reference in its entirety.

In addition, as shown in FIG. 4, the movable T-beams 204 may be mounted by means of rods 206 on eccentrics 208, 210 which are mounted on a shaft 212. Rotation of the shaft 212 about longitudinal axis C causes the eccentrics 208, 210 to rotate, which causes the movable T-beams 204 to slide, i. move back and forth, from side to side in the direction indicated by arrow B. Arrow B is oriented in the transverse direction, i.e. substantially perpendicular to the machine direction, which is represented by arrow A. In some cases, as shown in FIG. of the beams 204 will move from side to side in opposite directions due to the action of the eccentrics 208, 210. In other cases (not shown), the eccentrics 208, 210 can be set in phase with each other so that the movable tee beams 204 move together from side to side.

In all cases, the movement of the eccentrics 208, 210 causes the forming wire 102 to oscillate transversely with respect to the fixed T-beams 202. formed on the forming wire 102 as described in more detail with respect to FIG. The normal (straight) position of the forming wire 102 without the use of the vibrating table device 200 of the paper machine is illustrated in FIG. 4 with a solid line, while the moving position of the forming wire 102' (with exaggeration) during the use of the paper machine vibrating table device 200 is illustrated with a dotted line.

As another example, the thoracic shaft vibrating device 300, which is shown in partial cross section in FIG. 5, may be used according to any of the embodiments described herein (including the embodiment shown in FIG. 3, including two Fudrinier forming sections) to stimulate transverse vibrations of the forming fabric (not shown; see Figs. 1-4). The chest roll vibration device 300 is described in more detail in US Pat. No. 5,560,808, the disclosure of which is incorporated herein by reference in its entirety. As shown in FIG. 5, the breast shaft 104 is rotatably supported within the bearing arrangements 302, which are attached to the fixed portion 304 by a movable member 306. In some examples, the movable member 306 may include glass fiber springs. One of the bearing assemblies 302 is connected to the thoracic shaft vibrator 300 via a lever 308. The thoracic shaft vibrator 300 may include one or more hydraulic sliders assemblies (not shown) that actuate the lever 308, the bearing assemblies 302, the thoracic shaft 104, and the movable members 306 move from side to side in the direction indicated by arrow B, which is transverse to the machine direction (not shown; see FIGS. 1-4) and generally parallel to axis D of the breast shaft 104. The dashed lines in FIG. 5 shows the position of the breast roll 104, the bearings 302, and the movable members 306 as they move back and forth under the action of the breast roll vibrator 300 via the arm 308. Similar to the paper machine vibrating table apparatus 200 illustrated in FIG. 4, the movement of the breast roll 104 from side to side in Fig. 5 causes the forming wire (not presented; see fig. 1-4) oscillate laterally as the forming wire passes over the breast roll 104. In some embodiments (not shown), the paper machine vibrating table assembly 200 of FIG. 4 and the thoracic shaft vibrating device 300 in FIG. 5 can be used together in a single Fudrinier forming section.

In all embodiments, we believe that transverse or transverse vibrations of the forming fabric, as described herein, cause at least a portion of the fibers in the web composition to orient more in a direction that deviates from the machine direction, with the fibers those occupying the closest position to the forming wire, as a rule, the greatest transverse shear forces act, so that these fibers are oriented in the direction that deviates most from the machine direction. According to the prior art, when a single layer headbox is used in combination with transversely oriented forming wire vibrations, or the aqueous slurries of each layer in a multilayer headbox have the same composition, the inventors believe that the longest fibers tend to be evenly distributed throughout the thickness. web and the final paper product made from the web (see Fig. 6 and 7). The longest fibers are generally the strongest fibers in terms of providing the desired strength and flexural stiffness properties in the final paper product. When the forming fabric is subjected to transverse vibrations, since all layers generally contain the same number of longest fibers, only a limited number of longest fibers in the web, i. only those fibers closest to the forming wire will be subjected to transverse shear forces of sufficient magnitude to cause the fibers to orient in a direction that deviates from the machine direction. Most of the remaining longest fibers will generally be oriented in the machine direction.

As one example, in accordance with the present invention, the inventors believe that the first layer or layer closest to the forming wire will contain a significant amount of the longest fibers present in the web, and in addition that a significant part of the longest fibers will orient, position, or align in a direction that deviates from the machine direction. As described herein with respect to FIG. 1 and 2 to the lowest feed intake manifold, i. e. the first inlet manifold 12, 52 of the respective multilayer headbox 10, 50 receives the first aqueous slurry 20, 60 containing first fibers that have an average length greater than the average length of the fibers of the aqueous slurry entering at least the inlet manifold located above the first intake manifold (for example, into the second intake manifold 14, 54). Although the combination of the aqueous suspensions to form the respective jet 44, 94 provides some mixing of the aqueous suspensions, separation of the aqueous suspensions is known to be at least partially maintained in the respective web 46, 96 which is formed when the combined aqueous suspensions are deposited on the forming wire 102, thus that the web 46, 96 contains two or more layers or layers. Thus, the inventors believe that the first layer or ply 46-1, 96-1 of each web 46, 96 will generally contain fibers whose average length is greater than the average length of the fibers of the first ply or ply formed according to methods of the prior art. Similarly, as shown in FIG. 3, into the lowest intake manifold, i.e. the first intake manifold 52-1, 52-2 of each respective headbox 50-1, 50-2 receives the first aqueous slurry 60-1, 60-2 containing the first (longer) fibers, such that the first layer or the sheet 96A-1, 96B-1 of each respective web 96A, 96B that occupies the closest position to the respective forming wire 102-1, 102-2 will typically contain fibers having a greater average length.

In FIG. 6 is a top sectional view of the three-ply web 96 illustrated in FIG. 4 and made in accordance with this example, where parts of the second and third layers 96-2, 96-3 are cut out. The web 96 may be similar to the three-ply web 96 illustrated in FIG. 2 and may have a thickness T _W that generally extends perpendicular to both the machine direction and the transverse direction. In FIG. 6, the machine direction is represented by arrow A and the cross direction is represented by arrow B. The insets show idealized images of the first, second and third fibers 97-1, 97-2, 97-3, 97-3', which are located, respectively, in the first , second and third layers 96-1, 96-2, 96-3 of the web 96 that follows the weave of the forming wire as described herein. As shown in FIG. 6, the first fibers 97-1 have a first average length and the second fibers 97-2 have a second average length, the first average length being greater than the second average length. The third fibers 97-3, 97-3' have a third average length. In some cases, the third average length of the third fibers, such as 97-3 fibers, is less than one or both of the first length and the second average length. In other cases, the third average length of the third fibers, for example the fibers 97-3', is the same as or greater than the first average length of the first fibers 97-1.

In addition, as shown in FIG. 6, a significant portion of the first fibers 97-1 are caused to orient at an angle with respect to the machine direction. In some cases, the authors believe that at least the majority (>50%) of the first fibers 97-1 is oriented at an angle with respect to the machine direction. Since the second and third fibers 97-2, 97-3, 97-3' located in the second and third layers 96-2, 96-3 are located farther from the forming wire, the authors believe that the second and third fibers 97-2 , 97-3, 97-3' will be affected by lateral shear forces to a much lesser extent, and they will exhibit a significantly lower degree of deflection with respect to the machine direction compared to the first fibers 97-1.

The number of first fibers 97-1 angled with respect to the machine direction and the angles at which the first fibers 97-1 extend with respect to the machine direction may vary depending on the magnitude and frequency of the shear forces that the forming fabric applies to the the first fibers 97-1, as well as the speed of movement of the forming fabric in the machine direction and in the transverse direction. The inventors believe that the angles at which the first fibers 97-1 can run with respect to the machine direction can range from +1 degree to +90 degrees and from -1 degree to -90 degrees, with the machine direction corresponding to an angle of 0 degrees, as shown in Fig.6. For example, the deviation of the first fibers 97-1 with respect to the machine direction direction can be >0 degrees and ≤90 degrees. The specified ranges include all intermediate values and subranges, including +5, +10, +15, +20, +25, +30, +35, +40, +45, +50, +55, +60, +65 , +70, +75, +80 and +85 degrees and -5, -10, -15, -20, -25, -30, -35, -40, -45, -50, -55, -60, -65, -70, -75, -80 and -85 degrees.

Although web 96 shown in FIG. 6 includes three layers, the authors believe that these principles apply equally to webs that include two layers (for example, web 46 illustrated in Fig. 1), four layers, etc. In addition, the inventors also believe that these principles apply to embodiments such as the embodiment illustrated in FIG. 3, whereby two three-ply webs 96A, 96B formed in separate Fudrinier forming units 100-1, 100-2 are combined to form one six-ply web 98, and in FIG. 5, according to which the vibrating device 300 of the chest roll is used to stimulate the transversely oriented vibrations of the forming fabric 102 (see Fig. 1-4).

As shown in FIG. 1, 6 and 13, paper products that are made in accordance with the present invention, and in which the longest fibers are located closest to the forming wire (for example, delaminated sample 1), exhibit increased compressive strength in the transverse direction compared to the paper product. , made by methods in accordance with the prior art (for example, control and control vibration samples; see also example 3). The authors believe that the increase in lateral compression strength is due at least partially to the transverse vibration of the forming fabric on which the web is formed, which causes a significant part of the longest fibers to orient at an angle with respect to the machine direction. The inventors believe that this increase in lateral compression strength translates into an increase in compressive strength of a box or other container made from the paper product. As shown in FIG. 7A, a compressive force is applied to the stacked boxes 400 as represented by arrow F. Due to the tendency of fibers to MD and the limitations of conventional box machines, boxes 400 made from conventional paper products as shown in FIG. 7A generally have the greatest amount of compressive strength in the circumferential direction, as indicated by the arrow _CD . Since traditional boxes exhibit the greatest amount of compressive strength in a direction that is substantially perpendicular to the direction of the compressive force F, these boxes may be more prone to weakening and breaking. The authors believe that the methods described herein help solve this problem by causing at least a portion of the longest fibers to orient at an angle with respect to the machine direction, which increases the compressive strength, in particular, the compressive strength of boxes made from these paper products. As shown in FIG. 7B, we believe that a box 400' made from a paper product formed in accordance with the present invention will have increased compressive strength in the vertical direction, as indicated by the arrows V _D , which is substantially parallel to the direction of the compressive force F.

In addition, paper products that are made in accordance with the present invention, and in which the longest fibers are located closest to the forming wire (laminated sample 1), exhibit increased flexural rigidity compared to paper products made using traditional methods (controls). and control vibration samples, see example 2 below and Fig. 12). In FIG. 8 shows an exemplary final paper product 500 made in accordance with the present invention. The paper product 500 includes a first outer surface 502, a second opposite outer surface 504, and a thickness T _F . The paper product 500 may be made from a web comprising two or more layers or layers as described herein and may include, for example, paper or paperboard. As shown in FIG. 1, 6 and 8, the first layer or layer 46-1, 96-1 closest to the forming wire 102 includes primarily the first aqueous slurry 20 containing the first longest fibers 97-1 and the second layer or layer 46- 2, 96-2 mainly includes a second aqueous slurry 22 containing second shorter fibers 97-2. It is believed by the inventors that most of the fibers located on or near one outer surface, such as the first outer surface 502 of the final paper product 500, will be the longest first fibers 97-1 from the first layer or formation 46-1, 96-1 , although most of the fibers located near the opposite outer surface, such as the second outer surface 504, will be the second fibers 97-2 from the second layer or formation 46-2, 96-2. At least a portion of the first fibers 97-1 may deviate from the direction in which most of the second fibers 97-2 are oriented, as described herein. For example, most of the second fibers 97-2 may be oriented in the machine direction, and most of the first fibers 97-1 may be oriented in a direction that deviates from the machine direction. In some cases, as shown in FIG. 1, the second layer or layer 46-2, 96-2 may be the final layer or layer of the web 46, 96, and in other cases one or more additional layers or layers may be formed over the second layer or layer 46-2, 96- 2 (see FIGS. 2 and 3). Since the longest fibers tend to provide increased flexural rigidity, we believe that the increased flexural rigidity of the paper product 500 made in accordance with FIG. 1 and 6 is due at least in part to the fact that the longest first fibers 97-1 are located predominantly on or near one outer surface 502, as compared to a paper product made by prior art methods in which the longest fibers , as a rule, are evenly distributed throughout the thickness T _F of the paper product (see example 2 and Fig. 12).

In addition, the authors believe that the paper product 500, made from web 96, 96A, 96B, in which the longest fibers are closest to the forming wire, and which includes three or more layers, as shown in Fig. 2 and 3 will also exhibit an increase in bending stiffness. As shown in FIG. 2, 6 and 8, the first layer or ply 96-1 proximal to the forming wire 102 includes primarily a first aqueous slurry 60 containing first fibers 97-1; the second middle layer or layer 96-2 includes mainly the second aqueous suspension 62 containing the second fibers 97-2; and the third outer layer or layer 96-3 mainly includes a third aqueous slurry 64 containing third fibers 97-3, 97-3'. It is believed by the inventors that most of the fibers located on or near one outer surface, such as the first outer surface 502, of the final paper product 500 will constitute the longest first fibers 97-1 from the first layer or formation 96-1. Most of the fibers located near the opposite surface, such as the second outer surface 504, will constitute the second fibers 97-2 from the second layer or formation 96-2, and most of the fibers located on or near the opposite surface 504 will constitute the third fibers 97-3 , 97-3' from the third layer or formation 96-3, with at least some of the second fibers 97-2 located between the first and third fibers 97-1, 97-3, 97-3'.

In addition, as shown in FIG. 2, 6 and 8, in some of the examples that are described herein, the third average length of the third fibers, such as fibers 97-3 in FIG. 6 may be less than the first average length of the first fibers 97-1, and in other examples the third average length may be less than the first and second average lengths of the first and second fibers 97-1, 97-2. In both examples, the second average length is less than the first average length, and the authors believe that the first fibers 97-1, ie. the fibers having the largest average length will be located on or near one outer surface, for example, the first outer surface 502, of the paper product 500 such that the paper product 500 exhibits increased flexural rigidity (compared to a conventional paper product), as described above with respect to FIG. 1. In other examples, the third average length of the third fibers, such as fibers 97-3' in FIG. 6 may be the same as or greater than the first average length such that both outer surfaces 502, 504 of the paper product 500 include fibers with an average length that is greater than the average length of the fibers found within the paper product 500. The authors believe that that paper product 500 with longer fibers located at or near both outer surfaces 502, 504 may exhibit increased flexural rigidity compared to conventional paper products. The authors believe that these paper products can also exhibit higher bending stiffness than the paper products 500 described herein, in which the longest fibers are located on only one outer surface 502 or near it.

As shown in FIG. 3, 6 and 8, the first layer or ply 96A-1, 96 B-1 closest to the respective forming wire 102-1, 102-2 comprises primarily the first aqueous slurry 60-1, 60-2 containing the most long first fibers 97-1; the second middle layer or formation 96A-2, 96B-2 includes primarily a second aqueous slurry 62-1, 62-2 containing second shorter fibers 97-2; and the third outer layer or sheet 96A-3, 96B-3 includes primarily a third aqueous slurry 64-1, 64-2 containing third shorter fibers, such as fibers 97-3 in FIG. 6. The second average length of the second fibers 97-2 is less than the first average length of the first fibers 97-1, and the third average length of the third fibers 97-3 may be less than one or both of the first and second average lengths of the first and second fibers 97 -1, 97-2. In the final paper product 500, the webs 96A, 96B may be combined in such a way that the authors consider that the majority of the fibers located on or near the same outer surface, for example, the first outer surface 502, of the final paper product 500 will constitute the first fibers 97-1 from the first layer or ply 96A-1 of the first web 96A, and most of the fibers located on or near the opposite outer surface, such as the second outer surface 504, of the final paper product 500 will constitute the first fibers 97-1 from the first layer or ply 96B -1 second blade 96V. At least some second dies 97-2 from respective second layers or layers 96A-2, 96B-2 and third fibers 97-3 from respective third layers or layers 96A-3, 96B-3 of each web 96A, 96B are located between the first fibers 97-1 of the first layers or layers 96A-1, 96B-1. Since the first fibers 97-1 include fibers having the largest average length, we believe that both outer surfaces 502, 504 of the paper product 500 made using the embodiment shown in FIG. 3 will contain fibers with an average length that is greater than the average length of the fibers found within the paper product 500. As described with respect to FIG. 2, we believe that paper products 500 with longer fibers located at or near both outer surfaces 502, 504 may exhibit increased flexural rigidity compared to conventional paper products and also compared to paper products 500 described herein. a document in which the longest fibers are located on or near only one outer surface 502.

In another example, in accordance with the present invention, the authors believe that the first layer or layer closest to the forming wire will contain a significant amount of the shortest fibers present in the web, and in addition that a significant portion of the shortest fibers will be oriented, be located or aligned in a direction that deviates from the machine direction. As described herein with respect to FIG. 1 into the lowest feed intake manifold, i. e. the first inlet manifold 12 of the multilayer headbox 10 may receive a first aqueous slurry 20 containing first fibers having an average length that is less than the average length of the fibers of the aqueous slurry 22 entering the inlet manifold located above the first inlet manifold 12 (for example, into the second intake manifold 14). Although the combination of the aqueous slurries 20, 22 to form the jet 44 causes some mixing of the aqueous slurries 20, 22, separation of the aqueous slurries 20, 22 is known to be at least partially maintained in the web 46 that is formed when the combined aqueous slurries are deposited onto the forming wire 102 , and as a result, the canvas 46 includes two layers or layers. Thus, we believe that the first layer or layer 46-1 of the web 46 in this example will typically contain fibers with an average length that is less than the average length of the fibers in the second layer or layer 46-2.

In FIG. 10 is a top sectional view of a two-ply web 196 made in accordance with this example, in which a portion of the second layer 196-2 has been cut. Web 196 may have a thickness T _W that generally runs perpendicular to the MD and CD. In FIG. 10, the machine direction is represented by arrow A and the cross direction is represented by arrow B. The insets show idealized images of the first and second fibers 197-1, 197-2 located in the first and second layers 196-1, 196-2 of web 196, respectively. following the transverse oscillations of the forming wire, as described in this document. The first fibers 197-1 have a first average length and the second fibers 197-2 have a second average length, the first average length being less than the second average length.

In addition, as shown in FIG. 10, the authors believe that a significant portion of the first fibers 197-1 is forced to orient at an angle with respect to the machine direction. In some cases, the authors believe that at least the majority (>50%) of the first fibers 197-1 is oriented at an angle with respect to the machine direction. Since the second fibers 197-2 located in the second layer 196-2 are farther away from the forming wire, the inventors believe that the second fibers 197-2 will be subjected to much less lateral shear forces and exhibit a significantly reduced amount of deflection. relative to machine direction compared to the first fibers 197-1.

The number of first fibers 197-1 angled with respect to the machine direction and the magnitude of the angles at which the first fibers 197-1 extend with respect to the machine direction may vary depending on the magnitude and frequency of the shear forces that the forming fabric applies to the the first fibers 197-1, as well as the speed of movement of the forming fabric in the machine direction and in the transverse direction. It is believed by the inventors that the angles at which the first fibers 197-1 can run with respect to the machine direction can range from +1 degree to +90 degrees and from -1 degree to -90 degrees, with the machine direction corresponding to an angle of 0 degrees, as shown in Fig. 10. For example, the deviation of the first fibers 197-1 with respect to the machine direction direction may be >0 degrees and ≤90 degrees. The specified ranges include all intermediate values and subranges, including +5, +10, +15, +20, +25, +30, +35, +40, +45, +50, +55, +60, +65 , +70, +75, +80 and +85 degrees and -5, -10, -15, -20, -25, -30, -35, -40, -45, -50, -55, -60, -65, -70, -75, -80 and -85 degrees.

Although web 196 shown in FIG. 10 includes two layers, we believe that these principles apply equally to webs comprising three layers as described herein (eg, web 96 illustrated in FIG. 2). For example, as shown in FIG. 2 and 10 and as described above, the first layer or ply 96-1 proximal to the forming wire 102 comprises primarily a first aqueous slurry 60 containing first (smaller length) fibers that may be substantially similar to fibers 197-1 ; the second middle layer or layer 96-2 mainly includes a second aqueous slurry 62 containing second fibers (not shown); and the third outer layer or layer 96-3 primarily includes a third aqueous slurry 64 containing third (longer) fibers that may be substantially similar to fibers 197-2.

As shown in FIG. 1, 10 and 13, the authors believe that a paper product that is made in accordance with the present invention, and in which the shortest fibers are in the closest position to the forming wire (see, for example, delaminated sample 2), will exhibit increased compressive strength. in the transverse direction compared to a paper product made by methods in accordance with the prior art (see, for example, control and control vibration samples), but will exhibit reduced compressive strength in the transverse direction compared to a paper product in which the longest fibers occupy the closest position to the forming wire (layered sample 1). However, as discussed in detail below, it has surprisingly been found that the cross-direction compression strength (as reflected in the short-roller cross-compression study (SCT) results explained below) of a paper product made from a web in which the shortest fibers occupy the nearest position to the forming fabric (see layered sample 2) when a top-felt-defined press is used in production) is more than the lateral compression strength exhibited by both conventional paper products (control and control vibration sample) and the paper product made from a fabric in which the longest fibers occupy the closest position to the forming wire (stratified sample 1). The authors believe that this increased lateral compression strength determines the increased compressive strength of a box or other container made from a paper product as described above with respect to FIG. 7A and 7B.

In addition, the authors believe that a paper product that is made in accordance with the present invention, and in which the shortest fibers are located closest to the forming wire (laminated sample 2), will exhibit increased flexural rigidity compared to a paper product made by methods in accordance with the prior art (control and control vibration samples in Fig. 12), but will exhibit reduced bending stiffness compared to a paper product in which the longest fibers occupy the closest position to the forming wire (delaminated sample 1 in Fig. . 12). As shown in FIG. 1, 8, and 10, the first layer or layer 196-1 closest to the forming wire 102 includes primarily the first aqueous slurry 20 containing the first shortest fibers 197-1, and the second layer or layer 196-2 includes mainly thus, the second aqueous suspension 22 containing the second fibers 197-2 of greater length. It is believed by the inventors that most of the fibers located on or near one outer surface, such as the first outer surface 502, of the final paper product 500 will constitute the first shorter fibers 197-1 from the first layer or formation 196-1, although most of the fibers located near the opposite outer surface, for example, the second outer surface 504, will constitute the second fibers 197-2 of greater length from the second layer or layer 196-2. At least some of the first fibers 197-1 may deviate from the direction in which most of the second fibers 197-2 are oriented, as described herein. For example, most of the second fibers 197-2 may be oriented in the machine direction, and most of the first fibers 197-1 may be oriented in a direction that deviates from the machine direction. As discussed in Example 2 and shown in FIG. 12, the experimental results for flexural stiffness reflect these expectations, with the delaminated paper product sample 2 exhibiting a lateral flexural stiffness index that is slightly greater than the lateral flexural stiffness index of the reference vibratory paper product, but less than the index bending stiffness in the transverse direction of the delaminated sample 1 of the paper product. The authors believe that the increased flexural rigidity of the delaminated sample 2 paper product compared to the control and control vibration paper products is due at least in part to the fact that the longer second fibers 197-2 are located on or near the same outer surface 504, as opposed to a traditional paper product in which the longest fibers are generally evenly distributed throughout the thickness T _F of the paper product.

Similarly, we believe that a paper product 500 made from a web in which the shortest fibers are closest to the forming wire and which includes three layers as shown in FIG. 2 and described above will also exhibit an increase in bending stiffness compared to a paper product made by methods in accordance with the prior art. As shown in FIGS. 2 and 8, we believe that most of the fibers located on or near one outer surface, such as the first outer surface 502, of the final paper product 500 will be the first fibers of shorter length, such as fibers 197-1 in fig. 10 from the first layer or formation 96-1. Most of the fibers located near the opposite surface, for example, the second outer surface 504, will constitute the second fibers (not shown) from the second layer or formation 96-2, and the majority of the fibers located on or near the opposite surface 504 will constitute the third (more long) fibers, such as fibers 197-2 in FIG. 10 from a third layer or formation 96-3, with at least some of the second fibers located between the first and third fibers 197-1, 197-2. Because the longer fibers are located at or near one of the outer surfaces 502, 504, we believe that a paper product 500 made from a web in which the shortest fibers are closest to the forming wire, and which includes three layers, may exhibit increased bending stiffness compared to traditional paper products.

In all examples, due to the orientation of the first longest fibers at an angle with respect to the machine direction, alone or in combination with the location of the longest fibers on or near one or both of the outer surfaces of the final paper product, the authors believe that the paper product according to the present invention can be is made from less starting material than a conventional paper product, while maintaining substantially the same lateral compressive strength and lateral bending stiffness properties as a conventional paper product. Thus, the authors believe that a paper product made in accordance with the present invention using about n percent less starting material (for example, n percent fewer fibers) compared to a conventional paper product can have a ratio of machine tensile strength values direction and cross direction which is the same as or less than the ratio of tensile strengths in the machine direction and in the cross direction of a conventional paper product. The inventors believe that other properties, such as compressive strength and bending stiffness, of paper products made in accordance with the present invention can similarly be maintained at the level of a conventional paper product while reducing the amount of starting material required.

In FIG. 9 is a flow diagram illustrating an exemplary method for manufacturing a paper product. Although the components of the two-layer headbox 10 in FIG. 1, it should be understood that the method is not limited to this structure. The method may begin at 600 by providing a forming wire 102 supported by a chest roll 104 and at least one additional roll 106. The method may continue at 610 by rotating the forming wire 102 such that the top surface 102A of the forming wire 102 moves. in the machine direction (as shown by arrow A in Fig. 1). In some examples, at least one additional shaft may include a drive shaft 106, and driving the forming wire 102 may include driving the drive shaft 106. At 620, a multilayer headbox 10 is provided, including first and second intake manifolds 12, 14 and layered outlet of the multilayer headbox 42, wherein the first intake manifold 12 is located below the second intake manifold 14. In step 630, the first aqueous suspension 20 of first fibers enters the first intake manifold 12, and the second aqueous suspension 22 of the second fibers enters the second intake manifold 14, and the first fibers have a greater average length than the average length of the second fibers (see Fig. 6).

The process may continue at step 640 with the combined flows of the first and second aqueous suspensions 20, 22 in the area of the layered outlet of the multilayer headbox 42 with the formation of a jet 44 exiting through the layered outlet of the multilayer headbox 42. At step 650, the jet 44 of the combined and thus layered suspensions 20, 22 is delivered to the top surface 102A of forming wire 102. The jet 44 of the combined suspensions forms a web 46 on forming wire 102, with a greater percentage of first fibers than second fibers present near forming wire 102. In step 660, the forming wire 102 is oscillating in a transverse direction with respect to the machine direction (see FIGS. 4 and 5), which ensures that at least a significant number of the first fibers are oriented in a direction that deviates from the machine direction (see Fig. 6). In step 670, a paper product (see FIG. 8) is formed from the web 46 and the process can then be completed. The paper product made by this method may include, for example, paper or paperboard.

In some aspects, the method may further include maintaining the flows of the first and second aqueous slurries 20, 22 separate from each other as the first and second aqueous slurries 20, 22 move from the first and second inlet manifolds 12, 14 into the layered outlet area 42 of the multilayer headbox.

As one example, oscillating forming wire 102 in step 660 may include oscillating a fibrous oriented structure (e.g., paper machine vibratory table assembly 200 as shown in FIG. 4) in contact with forming wire 102. As another example, for example, vibrating the forming wire 102 in step 660 may include oscillating the breast roll 104 in a direction generally parallel to the axis of the breast roll 104 (e.g., by vibrating the breast roll device 300 as shown in FIG. 5). As a further example, forming wire 102 can be oscillated to cause a significant number of first fibers to orient in a direction ranging between >0 and ≤90 degrees with respect to the machine direction (see FIG. 6). The first fibers can be oriented with respect to the machine direction at an angle of +1 degree to +90 degrees and from -1 degree to -90 degrees, with the machine direction corresponding to an angle of 0 degrees. The specified ranges include all intermediate values and subranges, including +5, +10, +15, +20, +25, +30, +35, +40, +45, +50, +55, +60, +65 , +70, +75, +80 and +85 degrees and -5, -10, -15, -20, -25, -30, -35, -40, -45, -50, -55, -60, -65, -70, -75, -80 and -85 degrees.

In other aspects, as shown in FIG. 2, the multilayer headbox 50 may further include a third intake manifold 56 located above the second intake manifold 54, and the method may further include: introducing a third aqueous suspension 64 of third fibers into the third intake manifold 56; and combining the flow of the third aqueous slurry 64 with the flows of the first and second aqueous slurries 60, 62 in the layered outlet of the multilayer headbox 92 to form a jet 94 exiting through the layered outlet of the multilayer headbox 92 (see also FIG. 3). In some examples, the third fibers may have a shorter average length than the average length of the first fibers (see FIG. 56). In other examples, the third fibers may have an equal or greater average length than the average length of the first fibers (see FIG. 6).

In FIG. 11 is a flow diagram illustrating another exemplary method for manufacturing a paper product. The method may begin at 700 by providing a forming wire 102 supported by a chest roll 104 and at least one additional roll 106. The method may continue at 710 by rotating the forming wire 102 such that the top surface 102A of the forming wire 102 moves. in the machine direction (as shown by arrow A in Fig. 1). In some examples, at least one additional shaft may include a drive shaft 106, and bringing the forming wire 102 into rotation may include driving the drive shaft 106. layered outlet of a multi-layered headbox 42, in which the first inlet manifold 12 is located below the second inlet manifold 14. In step 730, the first aqueous suspension 20 of first fibers enters the first inlet manifold 12, and the second aqueous suspension 22 of the second fibers enters the second inlet manifold 14, and the first fibers have a smaller average length than the average length of the second fibers (see Fig. 10).

The method can continue at step 740 with the combination of the streams of the first and second aqueous suspensions 20, 22 in the area of the layered outlet of the multilayer headbox 42 with the definition of the jet 44 exiting through the layered outlet of the multilayer headbox 42. At step 750, the jet 44 of the combined and thus layered suspensions 20, 22 is delivered to the top surface 102A of forming wire 102. The jet 44 of combined slurries forms a web 46 on forming wire 102, with a greater percentage of first fibers than second fibers present near forming wire 102. In step 760, the forming wire 102 is caused to oscillate transversely with respect to the machine direction (see FIGS. 4 and 5), thereby ensuring that at least a significant number of the first fibers are oriented in a direction that deviates from the machine direction (see FIGS. . ten). At step 770, a paper product (see FIG. 8) is made from the web 46 and the process can then be completed. The paper product made by this method may include, for example, paper or paperboard.

In some aspects, the method may further include maintaining the flows of the first and second aqueous slurries 20, 22 separate from each other as the first and second aqueous slurries 20, 22 move from the first and second inlet manifolds 12, 14 into the layered outlet area of the multilayer headbox 42.

As one example, oscillating forming wire 102 in step 760 may include oscillating a fibrous oriented structure (e.g., paper machine vibratory table assembly 200 as shown in FIG. 4) in contact with forming wire 102. As another example, for example, oscillating the forming wire 102 in step 760 may include oscillating the breast roll 104 in a direction generally parallel to the axis of the breast roll 104 (e.g., by vibrating the breast roll device 300 as shown in FIG. 5). As a further example, the forming wire 102 may be oscillated to cause a significant number of first fibers to orient in a direction ranging between >0 and ≤90 degrees with respect to the machine direction (see FIG. 10). The first fibers can be oriented with respect to the machine direction at an angle of +1 degree to +90 degrees and from -1 degree to -90 degrees, with the machine direction corresponding to an angle of 0 degrees. The specified ranges include all intermediate values and subranges, including +5, +10, +15, +20, +25, +30, +35, +40, +45, +50, +55, +60, +65 , +70, +75, +80 and +85 degrees and -5, -10, -15, -20, -25, -30, -35, -40, -45, -50, -55, -60, -65, -70, -75, -80 and -85 degrees.

Examples

The following examples are presented to illustrate certain specific embodiments of the present invention. It should be understood that additional embodiments, not limited to the specific features described, correspond to the following experimental examples.

Main Products

Kraft fibers (long fibers) are made from wood kraft pulp by International Paper (Pensacola, FL, USA), the average length of the fibers is approximately 2.6 mm; and

old corrugated cardboard (OCC; short fibre) containers provided by International Paper (Henderson, Kentucky, USA), average fiber length is approximately 1.6 mm.

Example 1 Sample preparation

Sheets of samples having four different compositions were made using a single Fudrinier forming section. The first set consists of sheets of samples ("control samples") containing a mixture of 25% kraft fibers and 75% OSS and formed using a two-layer headbox, simulating a single layer molding at a speed of 1640 feet per minute (ft/min). Vibration was absent during the formation of sheets of control samples. The second set consists of sample sheets (“control vibration samples”) having the same composition as the control sample sheets and formed using a two-layer headbox simulating one-layer molding at a speed of 1640 ft/min using breast roll vibration (Valmet® FormMaster, pitch 30 mm, 7 Hz) during molding. The third set consists of sample sheets ("Laminated Sample 1") made using a two-layer or delaminated headbox in which the upper inlet manifold contains 100% OSS and the lower intake manifold contains 100% kraft fibers, with the sample sheets containing 75% OSS and 25% kraft fibers. Sheets of laminated sample 1 were formed using a two-layer headbox at a speed of 1640 ft/min while vibrating the chest roll as described with respect to the sheets of the control vibration sample. The fourth set consists of sample sheets ("Laminated Sample 2") made using a two-layer or delaminated headbox in which the upper inlet manifold contains 100% kraft fibers and the lower inlet manifold contains 100% OSS, with the sample sheets containing 75% OSS and 25% kraft fibers. Sheets of laminated sample 2 were formed using a two-layer headbox at a speed of 1640 ft/min while vibrating the chest roll as described with respect to the sheets of the control vibration sample.

Sample sheets were made using a single top felt-defined press including a four-shaft wet press section with a shoe press at the third roll. It is generally expected that the use of a top felt-driven press will result in a density gradient, with the side of the sheet near the felt ("felt side") having a higher density compared to the side of the sheet away from the felt.

For research, three sheets are randomly selected from each set. Five strips are cut transversely from each sheet to measure the lateral bending stiffness, and five strips are cut transversely from each sheet to measure the compressive strength in the transverse direction, thus obtaining 15 test specimens from each a set of sample sheets for each strength parameter. The strips used to measure the bending stiffness have dimensions of approximately 12.7 mm x 152.4 mm and the strips used to measure the compressive strength have dimensions of 15 mm x 100 mm. Strips are cut from the center third of each sheet when measured in the transverse direction to eliminate potential edge instability effects. Each strip is individually weighed and the areal density calculated (not shown).

Example 2 Flexural Stiffness

The transverse bending stiffness is measured for each of the 15 test specimens, and the bending stiffness index is calculated for each test specimen (flexural stiffness divided by areal density). The measurement of bending stiffness is carried out in accordance with the well known Technical Association of the Pulp and Paper Industry (TAPPI) study method Τ 543, which is incorporated herein by reference. The results illustrated in FIG. 12 represent the average bending stiffness indices (lateral bending stiffness indices) for all test specimens from each set of specimen sheets.

It can be expected that the control vibration test specimens will exhibit a higher transverse bending stiffness index than the control test specimens, and that the laminated test specimens 1 will exhibit a higher transverse bending stiffness index than the control vibration test specimens. In addition, the test laminated samples 2 can be expected to show a lower index of transverse bending stiffness than the test laminated samples 1. As shown in Fig.12, the bending stiffness indices in the transverse direction correspond to this expected trend.

Example 3: Short Roller Compression Studies (SCT)

The compressive strength in the transverse direction is measured for each of the 15 test samples, and for each test sample, the SCT index (the result of dividing the compressive strength by the surface density) is calculated. The measurement of compressive strength is carried out in accordance with the known test method TAPPI Τ 543, which is incorporated herein by reference. The results illustrated in FIG. 13 represent the average SCT indices for all test samples (CD-SCT index) from each set of sample sheets.

Control vibratory test specimens can be expected to exhibit a higher CD-SCT index than control test specimens, since vibrations in the forming fabric, as described herein, cause at least some of the fibers in the web composition to orient in a direction that deviates from machine direction. In addition, the test delaminated samples 1 can be expected to exhibit a higher CD-SCT index than the control vibratory test samples, since the longer fibers take the closest position to the forming wire, and they can be expected to orient in a direction that deviates from machine direction. In addition, the tested laminated samples 2 can be expected to exhibit a lower CD-SCT index than the tested laminated samples 1, since the fibers closest to the forming wire have a shorter length.

As shown in FIG. 13, Test Control, Vibration Control, and Stratified Samples 1 follow the expected trend, with Control Vibration Test Samples exhibiting a higher CD-SCT Index than Control Test Samples and Stratified Test Samples 1 exhibiting a higher CD-SCT Index than Control Vibration Test Samples . Surprisingly, however, it was found that the CD-SCT index of the tested stratified samples 2 was greater than the CD-SCT index of the tested stratified samples 1.

The authors believe that this unexpected finding in relation to the CD-SCT index of the investigated layered samples 2 may be due at least in part to the type or type of press used to form the sheets of samples. In a single top felt press, dewatering occurs predominantly from the top side of the sheet near the forming fabric to the top side of the sheet near the felt. The fine particles in the sheet composition will move to the side of the sheet near the felt. In addition, the use of a four-shaft wet press with a shoe press at the third roll further provides dewatering towards the top of the sheet where the fines are. Thus, the sheet may have a higher density on the side of the sheet near the felt compared to the density on the side away from the felt. For a bottom felt-driven press, the same density gradient can be expected to occur on the (under) side of the sheet near the felt. It can be expected that a press containing two felts creates a sheet with two areas of increased density on the upper and lower sides of the sheet adjacent to the felt.

Simulations were made of sheets made using a top felt-defined, bottom-felt-defined, two-felt press (data not shown). In the case of control and control vibratory sheets, the long and short fibers are substantially evenly distributed throughout the sheet, and thus press type can be expected to have less effect on relative CD-SCT indices and lateral bending stiffness. Because the sheets of delaminated Samples 1 and 2 have longer fibers on one side or the other, the type of press would be expected to have a greater impact on the relative CD-SCT indices and lateral bending stiffness.

The simulation modeling of the CD-SCT indices for the felt press determined closely with the experimental data described in the examples and presented in Figs. 12 and 13. by the upper felt press, is more than for all other sheets, including sheets of delaminated samples 1. In addition, as correctly predicted by the simulation, it can be expected that the bending stiffness index in the transverse direction of the sheets of delaminated samples 2 is less than the bending stiffness index in the transverse direction of sheets of delaminated specimens 1.

For a bottom felt-driven press, simulations show that the CD-SCT index and the lateral stiffness index for the control vibrating sheets are more than the corresponding indices for the control sheets, and the indexes for the sheets of delaminated specimens can also be expected to be 1 are more than the corresponding indices for the control vibration sheets. In addition, as shown by the simulation, it can be expected that the CD-SCT index and the transverse bending stiffness index for sheets of laminated sample 2 are less than the corresponding indices of sheets of laminated samples 1, and the CD-SCT index of sheets of laminated samples 2 is almost the same. the same as the CD-SCT index of the control vibration sheets, and the transverse bending stiffness index of the sheets of the delaminated samples 2 is slightly more than the transverse bending stiffness index of the control vibration sheets.

For a two-felt press, simulations show that the CD-SCT index and the lateral stiffness index of the control vibrating sheets are greater than the corresponding indices for the control sheets, and that the sheet indices of the delaminated samples 1 are greater than the respective indices. control vibration sheets. In addition, as simulations show, it can be expected that the CD-SCT index and the transverse bending stiffness index of the sheets of delaminated samples 2 are less than the corresponding indices of sheets of delaminated samples, with the CD-SCT index of sheets of delaminated samples 2 being only slightly less than for sheets of delaminated samples 1 and significantly more than for control vibrating sheets. In the case of a two-felt press, the predicted lateral stiffness index of the sheets of the delaminated samples 2 is substantially the same as the lateral stiffness index of the control vibrating sheets. Thus, the experimental data and simulation results simultaneously suggest that the density gradient created by different types of presses can affect the properties of the sheet, in particular the compressive strength, depending on the type of fibers (for example, long or short) that prevail in the region of high density.

Throughout this specification, ranges are used for conciseness in representing each and every value that falls within a given range, including all subranges within it.

Although specific embodiments of the present invention have been illustrated and described, it should be understood that various changes and modifications can be made without deviating from the idea and departing from the scope of the present invention. Thus, the appended claims are intended to cover all such changes and modifications that fall within the scope of the present invention.

Claims (23)

1. A method for manufacturing a paper product, the method comprising: providing a forming wire that is supported by the chest roll and at least one additional roll; bringing the forming fabric into rotation so that the upper surface of the forming fabric moves in the machine direction; providing a multilayer headbox including first and second intake manifolds and a layered outlet of the multilayer headbox, the first intake manifold located below the second intake manifold; introducing a first aqueous suspension of first fibers into a first intake manifold and a second aqueous suspension of second fibers into a second intake manifold, the first fibers having a shorter average length than the average length of the second fibers; combining the streams of the first and second aqueous suspensions in the area of the layer outlet of the multilayer headbox to form a jet exiting through the layer outlet of the multilayer headbox; directing a jet of the combined and thus layered suspensions to the upper surface of the forming wire, and the jet of the combined suspensions forms a web on the forming wire, and at the same time, near the forming wire, the first fibers are present in a higher percentage than the second fibers; bringing the forming fabric into an oscillatory motion in a transverse direction with respect to the machine direction, thereby ensuring the orientation of the first fibers in a direction that deviates from the machine direction; and fabrication of paper products. 2. The method according to claim 1, in which: at least one additional shaft includes a drive shaft; and bringing the forming fabric into rotation includes driving the drive shaft. 3. The method of claim 1, further comprising: keeping the first and second aqueous slurries separated from each other as the first and second aqueous slurries move from the first and second inlet manifolds to the layered outlet area of the multilayer headbox. 4. The method of claim 1 wherein oscillating the forming fabric comprises oscillating a fibrous oriented structure in contact with the forming fabric. 5. The method of claim 1, wherein oscillating the forming fabric comprises oscillating the breast roll in a direction generally parallel to the axis of the breast roll. 6. The method of claim 1, wherein the forming fabric oscillates causing the first fibers to orient in a direction at an angle between >0 and ≤90 degrees with respect to the machine direction. 7. The method of claim. 1, in which the paper product includes paper. 8. The method of claim. 1, in which the paper product includes cardboard. 9. A paper product comprising a first outer surface, a second outer surface and a thickness, and further comprising first fibers and second fibers, wherein the first fibers have a shorter average length than the average length of the second fibers; most of the fibers located near one of the first and second outer surfaces include first fibers, and most of the fibers located near the other of the first and second outer surfaces include second fibers; and most of the fibers located near the other outer surface, including the second fibers, are oriented substantially in the machine direction and most of the fibers located near one outer surface, including the first fibers, are inclined towards the transverse direction, with the thickness direction usually being perpendicular to the machine and cross directions . 10. The paper product of claim. 9, wherein the first fibers are deflected in a direction passing at an angle in the range between >0 and ≤90 degrees with respect to the machine direction.

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