Method for manufacturing a tissue paper web and tissue paper web and tissue paper web product thus obtained

Abstract

Method for manufacturing a tissue paper web, the method comprising: − Providing a pulp comprising recycled textile fibers, the recycled textile fibers comprising a mixture of cotton fibers and at least one other type of textile fibers, the recycled textile having an average fibers length between 0,5 mm and 1,5 mm; − Disaggregating the pulp for forming an aqueous suspension comprising recycled textile fibers; − Dispersing the recycled textile fibers in the said aqueous suspension; − Injecting said aqueous suspension on a forming fabric; − Pressing said aqueous suspension for forming an intermediate tissue web with at least one layer comprising recycled textile fibers; − Drying and creping the intermediate web, for obtaining the said tissue paper web, wherein the recycled textile fibers content is at least 5% in mass.

Description

[0001] Method for manufacturing a tissue paper web and tissue paper web and tissue paper product thus obtained

[0002]

[0001] The present invention relates to tissue paper web.

[0003]

[0002] More specifically, the invention relates to an ecological and economical tissue paper web with an increased softness, absorbency and bulk, particularly intended for hygienic and sanitary purposes, such as toilet papers and the like.

[0004]

[0003] Paper products are a specific kind of products comprising cellulosic fibers and manufactured from a pulp which is pressed and dried in order to get the paper product. Paper products should not be confused with non-woven materials, which are a different kind of products wherein fibers are bounded by mechanically interlocking them (for instance with needles or by hydroentangling), or with an adhesive or thermally by fusion of a binder.

[0005]

[0004] In the paper industry, the “tissue” world includes all paper products used for hygienic and sanitary purposes, both at home (“consumer” or “At Home” - AtH - products) and / or in public places (Away From Home - AFH - products): the term “tissue” therefore encompasses for instance toilet paper and kitchen towels but also handkerchiefs, napkins, industrial rolls, facial tissues, medical sheets, and other products from the industry. It contributes to improving hygiene, comfort, and convenience in our society, helping to reduce the spread of diseases.

[0006]

[0005] These tissue products are designed to include several important properties. For example, they should have good bulk, a soft feel and ought to have good strength and durability. Unfortunately, when steps are taken to enhance one property of the product, other characteristics of the product are often adversely affected. For example, if strength is increased, softness of the tissue paper would decline due to the increase of fiber-to-fiber bonds. Conversely, if softness increases, the strength is decayed due to limited fiber to fiber bonds.

[0007]

[0006] The tissue products production involves in general two stages: the manufacturing of a tissue paper web and its conversion into different finished products comprising a superimposition of tissue paper webs commonly called « ply ».

[0008]

[0007] Tissue paper webs can be manufactured in several ways, either through conventional processes such as conventional wet press (CWP) and light dry creped (LDC), or from recently developed more advanced methods such as Through Air Drying (TAD), Advanced Tissue Molding System (ATMOS) and Advanced New Tissue Technology (NTT). Even if different technics exist, they all involve a forming step, wherein a pulp of fibers is pressed, a dewatering step and / or drying step, and a creping step.

[0009]

[0008] The conversion of the tissue paper web into a final product, such as rolls of toilet papers, is characterized by several operations, namely: unwinding, winding, embossing, lamination, perforation, cutting, packaging, and palletizing.

[0010]

[0009] The main raw material used to produce tissue paper is cellulose pulp, which can be obtained from wood (for example: pine (long fiber / softwood) and eucalyptus (short fiber / hardwood)) or other fibrous plants (non-wood), such as bamboo, straw, hemp or cotton. The final tissue product characteristics depend not only on manufacturing and converting operations but also largely depend on the type of fiber(s) used in its manufacture.

[0011]

[0010] More recently, to the detriment of virgin pulp, the increasing use of recycled paper or cardboard fibers has been opted for the production of more sustainable tissue paper. However, waste papers used to manufacture recycled paper fibers have become less available, as the society becomes more digitalized. Coupled with the growing instability in pulp prices and the enhancement of tissue paper physical characteristics, there is a great need to explore new raw materials.

[0012]

[0011] In contrast to the scarcity of post-consumer paper, the textile industry continues to increase its production, namely clothes, with limited lifetime. Every year, many tons of textiles are made globally. These products, besides being responsible for significant carbon dioxide emissions and consuming large amounts of water, after being used, could be destined to remain in landfills or to be incinerated. Therefore, the integration of a circular economy system (i.e. , an economic system that is structured with the objectives of reduction in waste and consumption of resources) into the textile industry is crucial, as it will provide a fast and secure way towards sustainability.

[0013]

[0012] The use of recycled textile fibers for producing tissue paper web is mentioned in some prior art. However, one main obstacle when using recycled fibers is to get a product both soft and strong enough for being used as hygienic paper.

[0014]

[0013] Document EP1591584 discloses an example of a process for manufacturing tissue paper from secondary cotton fibers obtained from cotton rags. The secondary cotton fibers undergo a size reduction and a grading treatment, so that only properly sized fibers are used for manufacturing the tissue paper. However, this example involves that the textiles are processed for separating and selecting the cotton fibers from other textile fibers, which would increase the cost and the energy consumption. Moreover, according to this document, a maximum amount of 20 to 25% of secondary cotton fibers could be added to a conventional cellulose mixture in order to manufacture the tissue paper. The economic and ecological advantages for using recycled textile fibers are then limited.

[0015]

[0014] Document WO2024 / 019971 discloses a process for preparing textile materials for use in producing non-woven material, wherein the textile materials can contain cotton fibers and polyester fibers. However, as previously presented, nonwoven materials are not tissue paper products.

[0016]

[0015] Document US2021 / 0381166 discloses a process wherein textile pulp is mixed with wood pulp to produce packaging material and paper products. A proportion up to 55% of textile pulp is considered. However, this document does not disclose how the paper is manufactured from the pulp, in order to get in particular a tissue paper product soft enough for hygienic and sanitary use.

[0017]

[0016] Then, there is a need for a tissue paper product made from recycled textile wastes, presenting features which are adapted for hygienic and sanitary use, such as toilet paper, and which overcome the drawbacks of the state of the art.

[0018]

[0017] Thus, according to a first aspect, the invention relates to a method for manufacturing a tissue paper web, the method comprising:

[0019] Providing a pulp comprising recycled textile fibers, the recycled textile fibers comprising a mixture of cotton fibers and at least one other type of textile fibers, the recycled textile having an average fibers length between 0,5 mm and 1,5 mm;

[0020] Disaggregating the pulp for forming an aqueous suspension comprising recycled textile fibers;

[0021] Dispersing the recycled textile fibers in the said aqueous suspension;

[0022] Injecting said aqueous suspension on a forming fabric;

[0023] Pressing said aqueous suspension for forming an intermediate tissue web with at least one layer comprising recycled textile fibers;

[0024] Drying and creping the intermediate web, for obtaining the said tissue paper web, wherein the recycled textile fibers content is at least 5% in mass.

[0025]

[0018] The tissue paper web thus obtained presents combined specific features, such as caliper, bulk, absorption and softness, which cannot be found in the state of the art when considering the use of recycled textile fibers.

[0026]

[0019] According to an embodiment, during the drying and creping step, the intermediate tissue web may be dried up to a solid content between 93% and 98% in mass.

[0027]

[0020] According to an embodiment, the injecting step may be implemented on a multiple-layered headbox, and comprise the injection of said aqueous suspension comprising recycled textile fibers and the injection of at least another suspension of a different composition, forming a wet tissue web with at least two layers: A first layer comprising at least recycled textile fibers;

[0028] A second layer of different composition than the first layer.

[0029]

[0021] According to an embodiment, the drying and creping step could include a passage of the intermediate web on a Yankee cylinder surface. The first layer is then in contact with the surface of the Yankee cylinder, the second layer, opposed to the first layer, remaining free from direct contact with the surface of the Yankee cylinder.

[0030]

[0022] According to an embodiment, the second layer could be free of recycled textile fibers.

[0031]

[0023] According to an embodiment, before the injecting step, the starting suspension could be mixed with at least one type of fibers selected from a group comprising hardwood fibers and / or softwood fibers and / or non-wood fibers and / or secondary fibers. In other words, the pulp containing recycled textile fibers could be mixed with another pulp before the injecting step.

[0032]

[0024] According to an embodiment the recycled textile fibers content in the tissue paper could be above 25% in mass, preferentially above 30% in mass and more preferentially above 40% in mass in the tissue paper web.

[0033]

[0025] According to an embodiment the tissue paper web may present a basis weight from 8 to 50 g / m2. Preferentially, the basis weight could be less than 30 g / m2.

[0034]

[0026] In a second aspect, the invention relates to a tissue paper web obtained from the implementation of the method as presented here above.

[0035]

[0027] In a third aspect, the invention relates to a tissue paper product comprising at least one ply made from the said tissue paper web.

[0036]

[0028] Embodiments of the invention will be described below with reference to the drawings, described briefly below:

[0037] [Fig. 1] is a schematic illustration of a method for producing a tissue paper web according to an embodiment of the invention.

[0038] [Fig. 2] represents schematically an embodiment of a multiple-layered headbox for the method illustrated on figure 1.

[0039] [Fig.3] represents schematically a tissue paper web according to an embodiment of the invention.

[0040]

[0029] In the drawings, identical references designate identical or similar objects.

[0041]

[0030] The invention relates to a tissue paper web comprising pressed recycled textile fibers from fiber pulp.

[0042]

[0031] The expression “average fiber length” herein means the length-weighted average fiber length (or length-weighted mean length of the fibers), as defined in the standard ISO 16065-2.

[0032] The term “pressed” should be understood herein as encompassing every method wherein water is removed from the fibers under pressure. The most conventional methods for pressing are the use of a press, or of vacuum pumps.

[0043]

[0033] The expression “tissue paper web” used herein refers to a one-ply base tissue as obtained from a tissue machine. More precisely, a tissue paper web is a sheet of paper, i.e. containing cellulosic fibers, made by a process from a pulp and including a forming step under pressure, a dewatering step, a drying step and a creping step, wherein a doctor blade scrapes the tissue paper web off from the surface of a Yankee drum.

[0044]

[0034] The term “layer” refers herein to a stratification within a web. It is possible to form one or more layers by depositing one or more streams of pulp onto a wire during the forming step. Each layer could comprise the same fibers or different kinds of fibers and could comprise only one kind of fibers or a mixture of different kinds of fibers.

[0045]

[0035] The term “ply” is used herein to designate one tissue paper web when it is superimposed with other tissue paper webs.

[0046]

[0036] The expression “recycled textile fibers” refers herein to fibers obtained by textile recycling. More specifically, these fibers are produced from the recycling of textile wastes and / or used textiles, i.e. pre- and post-consumer textiles, respectively. For instance, pre-consumer textile can encompass unwanted or discarded textile, such as waste resulting from the manufacturing process, damaged or defective textiles and textile that were never sold. For instance, post-consumer textiles can encompass discarded garments or household textiles, such as sheets, towels, and pillowcases, that have been previously owned or used by consumers and are worn-out, damaged or outgrown.

[0047]

[0037] Recycled textile fibers could be distinguished from virgin textile fibers, i.e. non-recycled textile fibers, because recycled textile fibers are in general shorter, weaker, and exhibit a more frayed aspect than virgin textile fibers, and they also show lower uniformity in their characteristics. In particular, recycled textile fibers could present a greater variation in color, due for instance to textile dyeing and residual ink, than virgin textile fibers.

[0048]

[0038] “Textile” is an umbrella term that encompasses various fiber-based materials. These fibers are broadly classified into natural and man-made fibers, as presented in Piribauer, B & Bartl, A, 2019, ‘Textile recycling process, state of the art and current developments: A mini review’, Waste Management & Research, vol. 37, pp. 112-119. The most important natural fibers are: cellulosic fibers (e.g., cotton, flax, jute, sisal, wood), protein fibers (e.g., wool, silk) and mineral fibers (e.g., asbestos). On the other hand, man-made fibers can be subdivided into: regenerated fibers, i.e., unmodified (rayon, viscose, lyocell) and modified (cellulose acetate and triacetate), synthetic fibers (e.g., polyester, polyamide, polyacrylic, polyurethane), as well as refractory and industrial fibers (e.g., ceramic, carbon, glass). In general, textiles are produced through the spinning and subsequent weaving of textile fibers.

[0049]

[0039] By “textile recycling”, it is to be understood as the act of reprocessing preconsumer and post-consumer textile wastes to obtain fibers suitable for manufacturing new products. These fibers are referred to here as “recycled textile fibers”. Textile recycling can comprise for instance one or more of the following actions on the textile wastes and / or used textiles: shredding, grinding, washing, bleaching, sizing.

[0050]

[0040] The tissue paper web is manufactured from a pulp, called starting pulp, containing exclusively recycled textile fibers.

[0051]

[0041] According to the present invention, all fibers in the starting pulp originate from textile recycling and predominantly comprise cellulosic fibers, for instance more than 98%, which could involve a pre-selection of the textiles to be recycled or the implementation of techniques that allow separating the cellulose material from the noncellulose material. Such techniques, well-established in the art, are primarily employed in the production of dissolving pulp, which is essentially used to make viscose, lyocell, modal, acetate, and other types of regenerated fibers. These fibers are typically spun into yarns, woven or knitted into fabrics and finally cut and sewn into new high-quality textile products. Some examples of these techniques are described in the following patents:

[0052] - WO 2013 / 124265 discloses a method for regeneration of a cellulose containing material. The method makes it possible to remove non-cellulose parts of cloths.

[0053] - WO 2020 / 245053 relates to a method for selecting cellulose-containing used textiles and a method for manufacturing a cellulosic paper material from used textiles cellulose as starting materials.

[0054]

[0042] According to one embodiment of the invention, the recycled textile fibers in the starting pulp do not need to be totally of one kind but can be a mix of two or more kinds of fibers. As textiles are mainly made in cotton, the starting pulp comprises cotton fibers, and it also comprises at least one other type of textile fibers such as natural or man-made fibers as previously presented. The recycled textile fibers in the starting pulp have an average length between 0,5 mm and 1 ,5 mm (millimeters) and an average fiber diameter between 10 pm and 25 pm (micrometers). The fiber dimensions can be determined by techniques well-known in the art. Standards for measurement methods of fiber length such as International standards ISO 16065-1 and ISO 16065-2 could be applied. For instance, an instrument such as the L&W Fiber Tester, from Lorentzen & Wettre, model Code 912 plus (912+), which relies on image analysis, can provide the length-weighted average fiber length as an output data in conformity with ISO 16065-2.

[0055]

[0043] According to one further embodiment, the remaining fibers present in the tissue paper web of the invention, i.e., the fibers being not recycled textile fibers, are selected from fibers comprising hardwood fibers, such as eucalyptus, beech, aspen, acacia or birch fibers; softwood fibers such as pine, spruce, red cedar, Douglas fir, hemlock, and larch fibers; and non-wood fibers such as cotton, bagasse, hemp, linen, sisal, straw or flax fibers

[0056]

[0044] The expression “hardwood fibers” refers to fibrous materials derived from deciduous trees, such as eucalyptus, beech, aspen, acacia or birch. In the present invention, the hardwood fibers preferably used are derived from eucalyptus trees. Typically, hardwood fibers are “short” fibers with a length of 1 to 2 mm, a diameter of 15 to 30 pm, and a wall thickness of 2 to 3 pm.

[0057]

[0045] On the other hand, the expression “softwood fibers” refers to fibrous materials derived from coniferous trees, such as pine, spruce, red cedar, Douglas fir, hemlock, and larch. In the present invention, the softwood fibers preferably used are derived from pine trees. Compared to hardwood fibers, softwood fibers are “long” with typically a length between 3 and 4 mm, a diameter between 30 to 40 pm, and a wall thickness between 3 and 4 pm.

[0058]

[0046] Hardwood and softwood fibers are the main groups that constitute “wood fibers”.

[0059]

[0047] Regarding the expression “non-wood fibers”, it should be understood here as fibrous materials derived from non-woody plants or crops, such as cotton, bagasse, hemp, linen, sisal, straw or flax fibers.

[0060]

[0048] Furthermore, in another embodiment, the remaining fibers present in the tissue paper web of the invention, i.e., the fibers being not recycled textile fibers, can be primary fibers, a mixture of primary and secondary fibers or secondary fibers.

[0061]

[0049] According to the invention, the starting pulp could be mixed with another pulp comprising such other fibers, as it would be explained here below.

[0062]

[0050] The expression “primary fibers” refers here to virgin fibers, i.e. fibers that have never been used in tissue-making, which are obtained from the pulping process of wood and / or non-wood substances.

[0063]

[0051] The expression “secondary fibers” refers here in to recycled pulp fibers i.e. any fibrous mass that has undergone a manufacturing process (e.g. paper- or tissuemaking) and is being recycled as the raw material for the process of the present invention.

[0052] An example of a process for making a tissue paper web according to the present invention is now described. The tissue paper web according to the present invention comprises at least 5% in mass of recycled textile fibers.

[0064]

[0053] Such process could be implemented with conventional tissue making process or with advanced methods such as Through Air Drying (TAD), Advanced Tissue Molding System (ATMOS) and Advanced NTT Technology - which allow to produce a more structured / textured tissue web with a lower density than a web produced on a conventional tissue paper machine.

[0065]

[0054] In a first step, the starting pulp 1 is provided. As previously presented, the starting pulp is the pulp made from textile recycling. Then it could comprise exclusively recycled textile fibers. However, it could be mixed with other fibers, the proportion of each being adapted depending on the final targeted content of recycled textile fibers in the tissue paper web.

[0066]

[0055] The starting pulp 1 can be first submitted to a disaggregating step, wherein bales of starting pulp, with fibers originating from recycling textile, are disaggregated in a pulper 2. An aqueous suspension is obtained, with a consistency of around 6 wt.-% (percentage in mass) for instance. Fibers are separated in water, and possibly other solvents which could help in the disaggregation, in order to individualize the fibers. Despite the average length of recycled textile fibers in the starting pulp 1 being in the range of 0,5 to 1,5 mm (as mentioned above), there is significant heterogeneity in lengths, with very short fibers (fines) and very long fibers. Therefore, in this aqueous suspension, fiber clumps may exist, either because the longer fibers hindered disaggregation or because they promote subsequent fiber aggregation, as a result of system agitation.

[0067]

[0056] After the disaggregating step, the aqueous suspension enters a disperser 3, wherein it is subjected to a dispersing step, for dispersing, i.e. reducing the size of fiber clumps, and possibly eliminating fiber clumps. More precisely, the fiber width in the aqueous suspension could not be significantly affected by the dispersing step, whereas the average fiber length could be reduced approximately from 5% to 10% compared to the values when entering the disperser 3. The aqueous suspension should be processed through the dispersing system multiple times, as needed, until the majority of the fiber clumps are eliminated. Thus, subsequent problems in the tissue paper manufacturing process, such as clogging, are prevented. The Schopper-Riegler degree, as determined according to ISO 5267-1:1999, Determination of drainability - Parti : Schopper-Riegler method, of the aqueous suspension could be around 27-29 SR°. The Schopper-Riegler degree is a measure of the drainage capacity of the pulp: as the Schopper-Riegler degree increases, the drainage capacity of the pulp decreases.

[0068]

[0057] Following the dispersing step, optionally, the aqueous suspension could also pass through deflakers and cleaners (not illustrated). Depending on the desired final tissue product, the fibers may be refined using techniques well-known in the art.

[0069]

[0058] The aqueous suspension is consequently homogenous: the fibers are dispersed, and the clumps are drastically reduced, possibly eliminated.

[0070]

[0059] The aqueous suspension is then provided to a headbox 4. According to one of the embodiments of the present invention, the resulting homogeneous aqueous suspension of recycled textile fibers obtained could be mixed in the headbox with at least one another aqueous suspension (prepared separately) 5 of a different composition. For instance, the other aqueous suspension does not comprise recycled textile fibers but wood fibers and / or non-wood fibers and / or waste from paper industry making and / or recycled paper or cardboard fibers. The mixing of the aqueous suspensions is made in order to adapt the final targeted recycled textile fibers in the tissue paper web. In another embodiment, at least one another aqueous suspension 5 of a different composition could be provided to form at least one of the layers of the tissue paper web, or to form a web with layers of different fibrous composition, using a multi-layered headbox. The aqueous suspension comprising recycled textile fibers in the headbox has for instance a consistency (i.e a percentage in mass of solid matter to liquid) in the range of 0,5 to 1 ,5 wt.-%, preferably of 0,8 to 1 ,2 wt.-%.

[0071]

[0060] The aqueous suspension is injected or deposited by the headbox 4 onto a forming fabric 6, often called the “wire”, and enters a forming station 7, wherein it is subjected to pressure in a forming step. The forming step involves the formation of an intermediate tissue web 8 by pressing. More precisely, at the exit of the forming station 7 the intermediate tissue web is typically dewatered to a fiber consistency of between about 8% and about 35% (total web weight basis). Pressing in the forming station 7 could be obtained by gravity or vacuum dewatering. Further dewatering could also be obtained by pressing operations wherein the web is subjected to pressure developed by opposing mechanical members, for example cylindrical rolls. A shoe press can be used for the pressing operations.

[0072]

[0061] The dewatering step is then followed by a drying step, wherein the intermediate tissue web, still wet, is dried at the surface of a Yankee cylinder 9 up to a solids content of 93% to 98%. The drying process is performed by the steam-heated Yankee cylinder surface and by hot air flow from the hood 9’ placed above the surface of the Yankee cylinder and surrounding the Yankee cylinder. The drying is followed by creping, wherein a doctor blade 10 scrapes off the web from the surface of the Yankee cylinder, which crucially influences the properties of the finished tissue product. The surface of the Yankee cylinder could be sprayed with a coating to promote the adhesion between the web and the surface of the Yankee cylinder, and to protect the metal surface of the Yankee cylinder from the doctor blade 10. The pocket angle is preferably determined to be from 70° to 90°. The tissue paper web disclosed in this invention exhibits strong adhesion to the Yankee cylinder, therefore, a finer creping is achieved and a smoother / satin tissue surface on the final tissue web 11 is obtained.

[0073]

[0062] In the tissue paper web 11 thus obtained, the fibers are not bonded by mechanical interlocking, adhesives, or thermal fusion of a binder; instead, bonding between fibers is achieved merely through water removal, which allows the fibers to create bonds, such as hydrogen bonds, intrinsically between them.

[0074]

[0063] An example of a tissue paper web and a tissue paper product according to the invention will now be described.

[0075]

[0064] A tissue paper product refers herein to a multiple-ply final product made of tissue paper web and tailored to the end user’s need by further converting step.

[0076]

[0065] According to the present invention, recycled textile fibers establish solid bonds with the remaining fibers used.

[0077]

[0066] Consequently, the content of recycled textile fibers in the tissue paper web is not limited, and could be from 5% in mass, below which content the softness is not determinant, and up to 100% in mass. For instance, the recycled textile fibers content could be above 25% in mass, and preferentially above 40% in mass.

[0078]

[0067] In one preferred embodiment, the tissue paper web 11 is composed of two layers A and B wherein the first layer A comprises essentially fibers originating from recycling textile and a second layer B comprising essentially wood fibers.

[0079]

[0068] The first layer A and the second layer B are obtained during the forming step by a multi-layered headbox 4’ which deposits simultaneously and in a superimposed configuration two layers on the wire. More precisely, a first pulp T, which could be exclusively the starting pulp 1 or the starting pulp 1 mixed with another pulp, enters the multi-layered headbox 4’ together with a second pulp 1”. The first layer A, comprising recycled textile fibers, is the layer A in contact with the surface of the Yankee drum. Due to the crepe effect, the softer side of the tissue paper web is the side in contact with the surface of the Yankee drum. Therefore, to enjoy the satin feel provided by the recycled textile fibers and the crepe effect, it is preferable for the recycled textile fibers to be predominantly located in the first layer A: in other words, the first layer A contains more recycled textile fibers than the second layer B. The second layer B could be free from recycled textile fibers.

[0069] The number of layers could be increased. For instance, the second layer B could be covered on its two faces by a first layer A comprising recycled textile fibers.

[0080]

[0070] The present invention also relates to a tissue paper product comprising at least one ply made from the tissue paper web described above.

[0081]

[0071] After the manufacture of the tissue paper web, a final tissue product 12 is obtained through a step called “converting”, in a converting station 13. The finished tissue product 12, such as toilet paper or hand towels, depending on the desired final properties, can be obtained by combining for instance two to five plies during the converting step. The total basis weight of multiple-ply tissue products preferably does not exceed 90 g / m2and more preferably is lower 80 g / m2, e.g. lower than 65 g / m2.

[0082]

[0072] The tissue paper web, and the tissue paper product comprising such tissue paper web, presents specific properties.

[0083]

[0073] The table here below presents the results for three tissue paper webs produced as described here above, with a two layers configuration (i.e. formed with a two-layered headbox), wherein, as presented here above, the first layer is the layer that would in contact with the surface of the Yankee drum. The tissue paper webs tested have been produced on a conventional tissue machine with the following parameters:

[0084] - Yankee speed: 1525-1560 m / min

[0085] - Yankee pressure: about 7.0 bar

[0086] - Hood temperature (temperature applied on the Yankee drum): 370-380 °C

[0087] - first layer side refiner: 29-30 A (Ampere)

[0088] - second layer side refiner: 31-33 A

[0089] - doctor blade angle: 75°

[0090] - Dispersing system gap: 0.2-0.5 mm

[0091]

[0074] In the table:

[0092] HW stands for hardwood pulp, for example bleached hardwood kraft pulp (BHKP) from CMPC SA (Compania Manufacturera de Papeles y Cartones SA), Guaiba, standard grade;

[0093] SW stands for softwood pulp, for example bleached softwood kraft pulp (BSKP) from CMPC, Pacifico

[0094] TEX stands for recycled textile pulp, for instance recycled textile pulp Circulose® produced by RENEWCELL;

[0095] “Waste” stands for the fibers that are recovered from the water removed from the paper sheet in the tissue machine.

[0096]

[0075] The total weight basis could be measured according to ISO12625-6:2016 - Determination of grammage.

[0097]

[0076] The caliper, or thickness, could be determined according to ISO 12625- 3:2014 - Determination of thickness, bulking thickness and apparent bulk density and bulk. Samples are prepared for measurement, wherein each sample is a stack of eight base tissue webs, also called sheets. Therefore, the value obtained is the thickness of eight base tissue webs. To obtain the caliper per sheet, the thickness value of the eight base tissue webs should be divided by eight.

[0098]

[0077] The bulk of the tissue paper is calculated with the following formula: X = c / w,

[0099]

[0078] wherein :

[0100] - X = bulk (cm3 / g)

[0101] - c = mean caliper of a sheet (pm)

[0102] - w = basis weight of the sheets (g / m2)

[0103]

[0079] “Dry MD tensile” means the maximum strength, per unit width, applied on the tissue paper web once dried along the machine direction, before tearing. “Dry CD tensile” means the maximum strength, per unit width, applied on the tissue paper web once dried along the cross-machine direction, before tearing. Both could be determined according to ISO 12625-4:2022 - Determination of tensile strength, stretch at maximum force and tensile energy absorption.

[0104]

[0080] The absorption measures the water absorption capacity of the tissue paper. It is determined by measuring the mass of water that could be absorbed per mass of tissue paper web and could be determined according to ISO 12625-8:2010 - Waterabsorption time and water-absorption capacity, basket-immersion test method.

[0105]

[0081] The handfeel value is what humans feels while touching any kind of surface and could be measured by a TSA (Tissue Softness Analyzer). More precisely, a TSA, for instance form EMTEC, can measure different parameters which influence the handfeel. From the measurements, a proper algorithm can extrapolate a value for the handfeel. For instance, at least two measurements could be made with one TSA:

[0106] A sound measurement, which measures the noise produced by friction between a rotor with ceramic blades and the sample, with a charge of 100mN. The noise is measured from two sources: vibration of the sample (TS750 - smoothness) and vibrations of the blades (TS7 - softness).

[0107] A deformation measurement, wherein a load is applied progressively from 100 to 600 mN to the sample, and the deformation between 100 and 600 mN is measured in mm / N. The deformation is used to calculate the plastic deformation or stiffness (D - Stiffness).

[0108]

[0082] Other parameters could be taken into account for evaluating the handfeel, such as thickness of the material, number of plies, base weight, and the environmental conditions temperature and relative humidity. According to the invention, the algorithm used to calculate the hand feel value with TSA is "Base Tissue II".

[0109]

[0083] Example 1.1 is the reference, wherein no recycled textile fibers are incorporated.

[0110]

[0084] As could be seen from examples 1.1 to 1.3, the higher the recycled textile fibers content is, the higher the hand feel, the caliper and the absorption are.

[0111]

[0085] Then adding recycled textile fibers enhance the properties of the paper tissue web for being used in the manufacturing of hygienic paper rolls, for which in particular high softness is appreciated, and / or kitchen paper roll for in particular which high absorbency is useful.

[0112]

[0086] For instance, for a recycled textile fibers content of at least 5% in mass, preferentially at least 25%, preferentially at least 30%, and even preferentially at least 40%, and a total weight basis between 8 and 50 g / m2, the tissue paper web obtained according to the present invention could present:

[0113] - a caliper per sheet of at least 100 pm, for instance at least 122 pm, preferentially at least 126 pm, even preferentially at least 139 pm;

[0114] - a bulk of at least 5,00 cm3 / g, for instance at least 6,39 cm3 / g, preferentially at least 6,70 cm3 / g, even preferentially at least 7,24 cm3 / g;

[0115] - an absorption of at least 5,0 g / g, for instance at least 7,8 g / g, preferentially at least 8,1 g / g, even preferentially at least 8,8 g / g; - a softness as measured by handfeel of at least 70, for instance at least 75,2, preferentially at least 76,2, even preferentially 78,4.

[0116]

[0087] While exemplary embodiment of the invention has been described with reference to two main embodiments, it will be understood by those skilled in the art that various changes, omissions and / or additions may be made, and equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope thereof. Therefore, it is intended that the invention is not limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated any use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another.

Claims

CLAIMS

1. Method for manufacturing a tissue paper web, the method comprising: Providing a pulp comprising recycled textile fibers, the recycled textile fibers comprising a mixture of cotton fibers and at least one other type of textile fibers, the recycled textile having an average fibers length between 0,5 mm and 1,5 mm;Disaggregating the pulp for forming an aqueous suspension comprising recycled textile fibers;Dispersing the recycled textile fibers in the said aqueous suspension ;Injecting said aqueous suspension on a forming fabric;Pressing said aqueous suspension for forming an intermediate tissue web with at least one layer comprising recycled textile fibers;Drying and creping the intermediate web, for obtaining the said tissue paper web, wherein the recycled textile fibers content is at least 5% in mass.

2. Method according to claim 1, wherein during the drying and creping step, the intermediate tissue web is dried up to a solid content between 93% and 98% in mass.

3. Method according to any of claims 1 or claim 2, wherein the injecting step is implemented on a multiple-layered headbox, and comprise the injection of said aqueous suspension comprising recycled textile fibers and the injection of at least another suspension of a different composition, forming a wet tissue web with at least two layers:A first layer comprising at least recycled textile fibers;A second layer of different composition than the first layer.

4. Method according to the previous claim, wherein the drying and creping step includes a passage of the intermediate web on a Yankee cylinder surface, and wherein the first layer is in contact with the surface of the Yankee cylinder.

5. Method according to claim 3 or claim 4, wherein the second layer is free of recycled textile fibers.

6. Method according to any of the previous claims, wherein before the injecting step, the starting suspension is mixed with at least one type of fibers selected from a group comprising hardwood fibers and / or softwood fibers and / or non-wood fibers and / or secondary fibers.

7. Method according to any of the previous claims, wherein the recycled textile fibers content in the is above 25% in mass, and preferentially above 40% in mass in the tissue paper web.

8. Method according to any of the previous claims, wherein the tissue paper web presents a basis weight from 8 to 50 g / m2.

9. Tissue paper web obtained from the implementation of the method according to any of the previous claims.

10. Tissue paper product comprising at least one ply made from the tissue paper web according to claim 9.

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