Paper pulp containing a fibrous by-product

Abstract

A process for preparing paper pulp, comprising the following steps: - mixing (E10) a mass percentage of a fibrous by-product (10) with a complementary mass percentage of cellulose pulp (20), wherein the fibrous by-product (10) comprises at least one of the following: coffee husks obtained from roasting coffee beans, the coffee husks having a mass percentage of water-soluble compounds greater than 15% and a mass water content less than 20%, and textile dust having a length of less than 5 mm; and - refining (E20) the mixture to obtain the paper pulp. Figure for the abstract: Fig. 1

Description

Title of the invention: Paper pulp comprising a fibrous by-product. Technical field

[0001] The present exposition relates to the general technical field of processes for preparing paper pulp and paper, and that of paper pulp and paper, in particular packaging paper. STATE OF THE ART

[0002] Papermaking processes make it possible to transform fibrous raw materials, such as wood fibers, into paper pulp. The paper pulp is then used to produce paper, for example, packaging paper.

[0003] Conventional processes consist of manufacturing paper pulp primarily from wood fibers. These processes can be divided into mechanical, chemical, or thermomechanical methods. Each method aims to separate cellulose fibers from components such as lignin and hemicelluloses, while preserving the integrity and length of the fibers to guarantee the quality of the final paper. However, these processes have a significant environmental impact due to the felling of trees to obtain the wood fibers and the chemicals used in the corresponding papermaking process.

[0004] In order to reduce the environmental impact of papermaking, papers may incorporate, for example, by-products corresponding to industrial waste, such as coffee husks generated during the roasting of coffee beans. EP 3 440 260 B1 describes a process for manufacturing paper from coffee husks from which the soluble portion has been previously extracted. The coffee husks are refined after the extraction of their soluble portion and then mixed with wood fibers. US 7 927 460 B1 describes a process for manufacturing paper from coffee husks that have been previously ground in the presence of water. The coffee husks are then mixed with an aqueous suspension of traditional paper pulp fibers.However, these processes are energy-intensive due to the separate processing of the coffee husks and the paper pulp with which they are mixed, and are also relatively complex due to the processing of the coffee husks before they are mixed with the paper pulp fiber.

[0005] Other papers exist that incorporate textile by-products such as textile scraps or textile fibers. However, these papers have basis weights exceeding 150 g / m², due to the substantial size of the textile fibers. Furthermore, textile fibers also require pre-treatment before use. The production and refining of paper is very energy-intensive, due to the large size of the textile fibers. GENERAL STATEMENT

[0006] One aim of the present application is to remedy the aforementioned disadvantages by proposing a paper pulp preparation process with a reduced environmental impact and a reduced cost.

[0007] Another objective of the present application is to remedy the aforementioned disadvantages by proposing a paper pulp, packaging paper or packaging that has a reduced environmental impact and a reduced cost.

[0008] According to a first aspect, the present application relates to a process for preparing paper pulp, comprising the following steps: - a mixture of a mass percentage of a fibrous by-product with a complementary mass percentage of a cellulose pulp, wherein the fibrous by-product comprises at least one of the following: coffee husk obtained from roasting coffee beans, the coffee husk comprising a mass percentage of water-soluble compounds greater than 15% and a mass content of water less than 20%, and textile dust having a length of less than 5 mm; and - refining the mixture to obtain paper pulp.

[0009] The cellulose pulp can be obtained from the cooking of at least one of the following fibers: a wood fiber, an annual plant fiber.

[0010] The wood fiber may include at least one of the following fibers: a softwood fiber, a hardwood fiber. The annual plant fiber may include at least one of the following fibers: a flax fiber, a hemp fiber, a jute fiber, a rice fiber, a bagasse fiber, a miscanthus fiber.

[0011] The mass percentage of fibrous by-product in the mixture can be between 10% and 60%, for example can be between 20% and 40%.

[0012] The coffee film may have an average surface area of ​​less than 2 cm2, or even less than 1.5 cm2.

[0013] At least 95% of the fibers present in textile dust may have a length of less than 3 mm, or even a length of less than 2 mm.

[0014] During the refining stage, the paper pulp can be refined so as to have a Schopper-Riegler degree between 55 °SR and 100 °SR, for example between 65 °SR and 85 °SR.

[0015] The cellulosic pulp can be obtained by cooking at least one fiber from an annual plant, the process further comprising at least one pre-mixing step among cooking, peeling, washing and bleaching the fiber from an annual plant in order to obtain the cellulosic pulp.

[0016] The process may further include a post-refining step to purify the paper pulp.

[0017] The process may further include a post-refining step of adding an additive to the paper pulp. The additive may include at least one of the following: a retention agent, a dry strength agent, a wet strength agent, a sizing agent, mineral fillers, or a colorant.

[0018] According to a second aspect, the present application relates to a process for preparing a molded cellulose object, comprising the following steps: - preparation of paper pulp using a process according to the first aspect; - molding of paper pulp; and - drying the molded paper pulp to obtain a molded cellulose object.

[0019] According to a third aspect, the present application relates to a process for preparing a paper roll, comprising the following steps: - preparation of paper pulp using a process according to the first aspect; - feeding a headbox of a paper machine with paper pulp; - gradual draining of the paper pulp on a forming table; - drying the drained paper pulp to obtain a strip of paper; and - winding the strip of paper onto a mandrel to obtain a roll of paper.

[0020] The process for preparing a paper roll may further include a step of applying at least one functional layer to the drained and dried paper pulp, for example, a starch layer, a barrier layer, a sealing layer, or a micro-pigmented layer. The step of applying at least one functional layer may be carried out prior to winding. The step of applying at least one functional layer may be carried out on one or, alternatively, on both sides of the paper web.

[0021] According to a fourth aspect, the present application relates to a paper pulp prepared using the process according to the first aspect.

[0022] The paper pulp may have a Schopper-Riegler degree between 55 °SR and 100 °SR, for example between 65 °SR and 85 °SR.

[0023] According to a fifth aspect, the present application relates to a molded cellulose object obtained by means of the process according to the second aspect.

[0024] According to a sixth aspect, the present application relates to a packaging paper obtained by means of the process according to the third aspect.

[0025] The packaging paper may have a basis weight between 10 g / m2 and 50 g / m2, for example between 18 g / m2 and 25 g / m2.

[0026] According to a seventh aspect, the present application relates to packaging comprising wrapping paper according to the sixth aspect or an object made of molded cellulose according to the fifth aspect. DESCRIPTION OF THE FIGURES

[0027] Fig. 1 represents a block diagram of a process for preparing paper pulp according to a first embodiment.

[0028] Figure [Fig.2] represents a block diagram of a process for preparing paper pulp according to a second embodiment compatible with the first embodiment.

[0029] Fig. 3 represents a block diagram of a process for preparing a molded cellulose object according to one embodiment, from paper pulp.

[0030] Fig. 4 represents a block diagram of a process for preparing a roll of paper according to a first embodiment, from paper pulp.

[0031] Figure 5 shows a block diagram of a process for preparing a roll of paper according to a second embodiment, from paper pulp.

[0032] Throughout the figures, similar elements bear identical references. DETAILED DESCRIPTION Manufacturing process

[0033] A process for preparing paper pulp, illustrated by way of non-limiting example in [Fig. 1], comprises the following steps: - mixture E10 of a mass percentage of a fibrous by-product 10 with a complementary mass percentage of a cellulose pulp 20, wherein the fibrous by-product 10 comprises at least one of the following: coffee husk obtained from roasting coffee beans, the coffee husk comprising a mass percentage of water-soluble compounds greater than 15% and a mass content of water less than 20%, and textile dust having a length of less than 5 mm; and - E20 refining of the mixture to obtain paper pulp.

[0034] The paper pulp thus prepared incorporates a fibrous by-product 10, which corresponds to an unrecovered industrial waste, generated in the case of coffee husks during the roasting of coffee beans, and in the case of textile dust during the production or processing of a textile product. The paper is therefore manufactured with a reduced environmental impact. Furthermore, the use of the fibrous by-product 10 does not degrade the visual or mechanical properties of the paper.

[0035] When the fibrous by-product 10 is coffee husk, the raw coffee husk, that is to say, directly from roasting and which therefore has a mass percentage of water-soluble compounds greater than 15% and a mass water content Less than 20%, the coffee hulls used for blending can be mixed with cellulose pulp without prior chemical or mechanical treatment. This simplifies and reduces the cost of the pulp preparation process. In particular, the coffee hulls used for blending have not undergone any extraction of their soluble fraction, grinding in the presence of water, or refining between roasting and blending. Furthermore, the entire coffee hull can be used for blending, which also contributes to reducing the cost of pulp preparation.

[0036] When the fibrous by-product 10 is textile dust, the raw textile dust, i.e., directly from the production or processing of the textile product and therefore less than 5 mm in length, can be mixed with the cellulosic pulp 20 without prior chemical or mechanical treatment. This simplifies and reduces the cost of the paper pulp preparation process. In particular, the textile dust used for mixing has not undergone any cutting, shredding, defibration, or refining prior to mixing. Furthermore, all of the textile dust can be used for mixing, which also helps to reduce the cost of paper pulp preparation.Finally, due to the short length of textile dust, the presence of textile dust in the mixture allows its use in paper with a reduced basis weight and allows E20 refining of the mixture to obtain the same level of refining which is less energy-intensive than refining a mixture which would contain a textile fiber.

[0037] Finally, the combined E20 refining of the mixture of the fibrous by-product 10 and the cellulose pulp 20 to obtain paper pulp provides an energy saving compared to separate refining of the cellulose pulp 20 and the fibrous by-product 10 upstream of their E10 mixture. Furthermore, such combined E20 refining of the mixture allows for better preservation of the fiber length of the cellulose pulp 20 used for the same level of refining, particularly in the case of pulp obtained from the cooking of wood fiber, compared to separate refining of the cellulose pulp 20 and the fibrous by-products 10. In addition, the presence of coffee hulls in the mixture allows for faster E20 refining, and therefore less energy-intensive, than refining cellulose pulp 20 alone. Coffee hulls

[0038] The term "coffee skin", or silver film, refers to a fibrous by-product 10 resulting from the roasting of coffee beans. It corresponds to a thin membrane that surrounds the coffee bean before it is roasted.

[0039] The mass percentage of water-soluble compounds in the raw coffee husk, i.e., directly from the manufacturing process in the absence of treatments subsequent chemical or mechanical, is classically greater than 15%, or even greater than 20%, and less than 60%, or even less than 30%.

[0040] The mass content of water in the raw coffee husk is classically less than 20%, or even less than 15% or even less than 10%.

[0041] A raw coffee film classically has an average surface area of ​​less than 2 cm2, or even less than 1.5 cm2.

[0042] A raw coffee film classically has an average thickness of between 20 micrometers and 80 micrometers, in particular between 40 micrometers and 60 micrometers. Textile dust

[0043] The term "textile fiber" refers to a by-product of the production or processing of textile products. It generally originates from textile material cutting scraps. Raw textile dust, that is, directly resulting from the production or processing of textile products without subsequent chemical or mechanical treatments, has a length greater than 5 mm, generally greater than 10 mm.

[0044] The term “textile dust” refers to a fibrous by-product 10 resulting from the production, use or processing of textile products and is generally in the form of a particle smaller than a textile fiber. Textile dust has a length of less than 5 mm.

[0045] At least 95% of the fibers present in textile dust, particularly in raw textile dust, may have a length of less than 3 mm. In other words, at least 95% of the particles corresponding to textile dust have a length of less than 3 mm. The average length of the fibers present in raw textile dust may be less than 2 mm, or even less than 1 mm.

[0046] At least 95% of the fibers present in the raw textile dust may have a width of less than 40 micrometers. An average width of the fibers present in the raw textile dust may be less than 35 micrometers, or even less than 25 micrometers.

[0047] A percentage of fibers present in raw textile dust with a length of less than 0.2 mm can be greater than 20%, or even greater than 25%.

[0048] The mass content of water in raw textile dust is classically less than 20%, or even less than 10%. Fibrous by-product

[0049] The fibrous by-product 10 used for mixing E10 with the cellulosic pulp 20 can correspond to a mass of coffee husks or a mass of textile dust, for example in the form of textile fluff.

[0050] The fibrous by-product 10 used for mixing E10 with the cellulosic pulp 20 may comprise a fibrous by-product 10 of a single type, or alternatively a mixture of different fibrous by-products 10. For example, the fibrous by-product 10 used for mixing may comprise only coffee skins, or only textile dust, or alternatively may comprise a mixture of coffee skins and textile dust. Cellulose pulp

[0051] The term "cellulose pulp" refers to any pulp that can be used to manufacture paper. The cellulose pulp 20 may be obtained by cooking a fiber and may not have undergone any refining prior to mixing E10 with the fibrous by-product 10.

[0052] The cellulose pulp 20 can be obtained by cooking at least one of the following fibers: a wood fiber, an annual plant fiber. The term "annual plant" refers to a plant that completes its life or harvest cycle in a single year or growing season, often in less than twelve months.

[0053] The wood fiber may include at least one of the following fibers: a softwood fiber, a hardwood fiber. The annual plant fiber may include at least one of the following fibers: a flax fiber, a hemp fiber, a jute fiber, a rice fiber, a bagasse fiber, a miscanthus fiber.

[0054] Cellulosic paste 20 can thus be obtained, for example, by isolating the cellulose fibers contained in wood or in an annual plant.

[0055] The cellulose pulp 20 used for the E10 blend can be obtained by boiling a single fiber or a blend of several fibers, including wood fibers and / or annual plant fibers. The type(s) of fiber used to obtain the cellulose pulp 20 can be chosen according to the cost of the fiber and / or the desired properties of the paper. For example, the cellulose pulp 20 used for the blend can be a pulp obtained by boiling only wood fibers, or a blend of a pulp obtained by boiling wood fibers and a pulp obtained by boiling flax or hemp fibers. A cellulose pulp 20 obtained by boiling wood fibers can be used for a wide range of applications, for example, for printing papers, board, and packaging.A cellulose pulp 20 obtained from the cooking of annual plant fibers such as flax or hemp can be used for paper with a long lifespan and a lower environmental impact. Blend.

[0056] The mass percentage of fibrous by-product 10 in the mixture can be between 10% and 60%, for example between 20% and 50%, for example between 30% and 40%, or can be equal to any value within these ranges. Such mass percentages make it possible to achieve to a pulp, and then to a paper, exhibiting satisfactory physical properties, for example, satisfactory mechanical strength, processing properties, tensile strength, and / or durability. The pulp produced by this process can be used to prepare paper suitable for various uses, for example, molded cellulose products or packaging paper.

[0057] Mass percentage represents the mass of a component relative to the total mass of a mixture or solution. For example, a mass percentage of 30% of fibrous by-product 10 means that there are 30 kg of fibrous by-product 10 in 100 kg of the total mixture of fibrous by-product 10 and cellulose pulp 20. Therefore, in this case, there will be 70 kg of cellulose pulp 20 in the 100 kg of total mixture.

[0058] For example, the mixture may comprise a mass percentage of coffee husks equal to 30% and a mass percentage of cellulose pulp 20, for example, obtained from the cooking of wood fibers, equal to 70%. The coffee husks present in the mixture will then have a total mass corresponding to 30% of the total mass of the mixture. Alternatively, the mixture may comprise a mass percentage of coffee husks equal to 50% and a mass percentage of cellulose pulp 20, for example, obtained from the cooking of wood fibers, equal to 50%. Alternatively, the mixture may comprise a mass percentage of textile dust equal to 30% and a mass percentage of cellulose pulp 20, for example, obtained from the cooking of wood fibers, equal to 70%. The textile dust present in the mixture will then have a total mass corresponding to 30% of the total mass of the mixture.Alternatively, the mixture may comprise a mass percentage of textile dust equal to 50% and a mass percentage of cellulose pulp, for example obtained from the cooking of wood fibers, equal to 50%.

[0059] The mass percentage of fibrous by-product 10 can be adjusted according to the desired paper basis weight. For example, for paper with a basis weight of less than 25 g / m², the mass percentage of fibrous by-product 10 can be less than 30%, and for paper with a basis weight of more than 40 g / m², the mass percentage of fibrous by-product 10 can be more than 30%. Refining

[0060] E20 refining is a mechanical treatment that shortens, hydrates, and fibrillates the fibers present in the mixture by applying compression and shear forces to the fibers. The fibrils help increase the bonds between fibers, and the cutting process, which reduces fiber length, improves their distribution in the pulp and subsequently in the resulting paper. The refined pulp is thus more suitable for preparing a molded cellulose object or a paper web, for the purpose of producing paper such as packaging paper.

[0061] The E20 refining can be carried out in one or more double-disc refiners and / or one or more conical refiners, for example by means of a continuous flow Claflin refiner and / or by means of a refining stack such as a Jones stack.

[0062] A double-disc refiner comprises a fixed disc and a moving disc, between which the mixture is compressed and sheared to shorten the fibers it contains. A refining stack comprises a cylinder and one or more rotating blades, between which the mixture passes and is cut to shorten the fibers it contains.

[0063] Refining parameters E20, such as the applied shear effect or refining time, are adjusted to preserve the length and properties of the blended fibers according to the desired Schopper-Riegler degree. Thus, the paper pulp containing the refined fibers can subsequently be easily drained E62 and effectively retained on the forming cloth.

[0064] The Schopper-Riegler degree (°SR) indicates the rate at which water can be extracted from a dilute pulp suspension. The Schopper-Riegler degree is measured at the end of the E20 refining process, using any suitable apparatus, for example, an apparatus conforming to ISO 5267-1:2000.

[0065] Paper pulp can have a Schopper-Riegler degree between 55 °SR and 100 °SR, for example between 65 °SR and 85 °SR, for example between 70 °SR and 80 °SR, for example equal to approximately 75 °SR. Such Schopper-Riegler degree ranges correspond to good physical properties of the paper pulp, particularly for its molding E51 and drying E52 to manufacture the molded cellulose object or for its draining E62 to manufacture the paper web.

[0066] When the fibrous by-product 10 includes coffee husk, refining E20 can be carried out for a refining time of less than 1h30, for example, between 45 minutes and 1h5. The refining time of a mixture comprising coffee husk and cellulose pulp 20 can be less than the refining time of cellulose pulp 20 alone. For example, for a mixture comprising a mass percentage of coffee husk equal to 50% and a mass percentage of cellulose pulp 20 obtained from the cooking of wood fibers equal to 50%, a refining time to obtain a Schopper-Riegler degree of 75 °SR can be about 50 minutes, whereas the refining time would be about 75 minutes for cellulose pulp alone. The presence of coffee skins in the mixture therefore reduces the refining time, and thus the energy consumed by refining E20.The higher the mass percentage of coffee hulls in the blend, the shorter the refining time required to achieve the same level of refinement, i.e., the same Schopper-Riegler degree. Furthermore, for the same level of refinement, the average fiber length in the refined blend containing hulls... The average fiber length in coffee pulp is greater than that of pulp refined alone. The presence of coffee bran therefore helps preserve fiber length, for the same level of refinement. This allows for the preservation of the mechanical properties of the paper obtained from this pulp. For example, for a Schopper-Riegler degree of 73 °SR, the average fiber length of pulp refined from an E10 blend of coffee bran and 20% cellulose pulp can range from 0.9 mm to 1.3 mm, compared to less than 1 mm for pulp refined alone, and the proportion of fibers longer than 1.5 mm is increased. Fibrillation is also improved.

[0067] When the fibrous by-product 10 includes textile dust, the refining E20 can be carried out for a refining time exceeding 45 minutes, for example, between 1h and 2h. The refining time of a mixture comprising textile dust and a cellulose pulp 20 can be substantially equivalent to the refining time of cellulose pulp alone. For example, for a mixture comprising a mass percentage of textile dust equal to 30% and a mass percentage of cellulose pulp 20 obtained from the cooking of wood fibers equal to 70%, a refining time to obtain a Schopper-Riegler degree of 75 °SR can be approximately 1h. For the same level of refining, the average fiber length in the refined mixture comprising textile dust is greater than the average fiber length in the cellulose pulp that would be refined alone.The presence of textile dust thus helps to preserve fiber length, for the same level of refining. This allows for the preservation of the mechanical properties of the paper obtained from this pulp. For example, for a Schopper-Riegler degree of 70 °SR, the average fiber length of paper pulp refined from an E10 mixture of textile dust and 20% cellulosic pulp can be between 1.1 mm and 1.5 mm, compared to a length of less than 1 mm for refined cellulosic pulp alone, and the proportion of fibers longer than 1.5 mm is increased. Fibrillation is also improved.

[0068] Refining E20 can be carried out at a dry fiber concentration of between 2% and 6%, for example, between 3% and 5%. Dry fiber corresponds to all the fibers of the fibrous by-product 10 and the fibers of the cellulosic pulp 20 contained in the paper pulp. The concentration corresponds to the mass of dry fiber, expressed in grams, relative to the total volume of the mixture of dry fiber and liquid, in particular water, present in the paper pulp, expressed in liters. The whole is expressed as a percentage. For example, a dry fiber concentration of 4%, i.e., 40 g / L, corresponds to a mass of 40 g of dry fiber present in a volume of 1 L of paper pulp.

[0069] One or more additional refinements may be carried out, for example in a double-disc refiner and / or a conical refiner. The mixture may undergo each additional refinement one or more times, depending on the desired final properties of the pulp and paper. Purge

[0070] The process may further include a post-refining step E20 involving the purification E30 of the paper pulp. Purification E30 removes impurities, agglomerates, or large particles that may be present in the paper pulp, such as coffee bean residues from the roasting by-product. Such purification E30 improves paper homogeneity and reduces the potential risk of machine breakage or other papermaking problems due to these impurities.

[0071] One or more additional refinements may for example take place after purification E30. Adding an additive

[0072] The process may further include a post-refining step E20 of adding an additive E40 to the paper pulp. The addition of one or more additives E40 improves the properties of the paper pulp and / or paper, for example, to facilitate the subsequent manufacture of the paper reel or the molded cellulose object.

[0073] The additive may include at least one of the following: a retention agent, a dry strength agent, a wet strength agent, a bonding agent, mineral fillers, a colorant.

[0074] The addition of the E40 additive can, for example, take place after the E30 purification, and before or after one or more additional refinings. Cellulose pulp production

[0075] As illustrated by way of non-limiting example in [Fig.2], the process may further include at least one pre-mixing step E10 from among a cooking El, a peeling E2, a washing E3 and a bleaching E4 of the wood or annual plant fiber in order to obtain the cellulosic pulp 20. In particular, when the cellulosic pulp 20 is obtained from the cooking of at least one annual plant fiber such as a flax fiber or a hemp fiber, the process may further include at least one pre-mixing step E10 from among a cooking El, a peeling E2, a washing E3 and a bleaching E4 of the annual plant fiber in order to obtain the cellulosic pulp 20.

[0076] The cooking El of the fiber can be carried out in a washing machine. Cooking parameters El, such as cooking time, cooking pressure and / or a The composition of a cooking solution can be adapted according to the nature of the fiber to be cooked and the desired properties of the cellulose pulp.

[0077] The E2 unwinding process can be carried out in a dewinding stack. The E2 unwinding process allows for an initial shortening of the fibers. Parameters of the E2 unwinding process, such as the unwinding time, can be adapted according to the nature of the fiber to be unwinded and the desired properties of the cellulose pulp 20.

[0078] The E3 wash may include black liquor extraction and / or wash liquor extraction. The wash liquors may include a mixture of wash water and sodium hydroxide (NaOH). The E3 wash may be carried out during and / or after the E2 deburring.

[0079] The E4 bleaching can be carried out in a bleaching machine, and allows the cellulosic pulp 20 to be lightened and / or purified, while preserving its fibers.

[0080] Method for preparing a molded cellulose object

[0081] A process for preparing a molded cellulose object, illustrated by way of non-limiting example in [Fig.3], comprises the following steps: - preparation of paper pulp using a process as described above; - E51 molding of paper pulp; and - E52 drying of the molded paper pulp so as to obtain a molded cellulose object.

[0082] The process for preparing a molded cellulose object described above offers advantages similar to those of the paper pulp preparation process described above. In particular, it allows the preparation of a molded cellulose object using a fibrous by-product 10 without prior treatment of the fibrous by-product 10 and with a less energy-intensive E20 refining of the mixture that better preserves fiber length, for a wide range of weights of the molded cellulose object. This makes the molded cellulose object preparation process simpler, less expensive, and reduces its environmental impact.

[0083] A molded cellulose object can be obtained by means of a molded cellulose object preparation process as described above. The molded cellulose object can, for example, be a cellulose tray. Method for preparing a roll of paper

[0084] A method for preparing a roll of paper, illustrated by way of non-limiting example in [Fig.4], comprising the following steps: - preparation of paper pulp using a process as described above; - feeding E61 of a headbox of a paper machine with paper pulp; - progressive draining E62 of the paper pulp on a forming table; - drying E63 of the drained paper pulp to obtain a strip of paper; and - winding E64 of the paper strip onto a mandrel to obtain a roll of paper.

[0085] The paper reel preparation process described above offers advantages similar to those of the paper pulp preparation process described above. In particular, it allows a paper reel to be prepared using a fibrous by-product 10 without prior treatment of the fibrous by-product 10 and with a less energy-intensive refining E20 of the mixture that better preserves fiber length, for a wide range of paper web weights wound onto the core. This makes the paper reel preparation process simpler, less expensive, and reduces its environmental impact.

[0086] A paper machine may include a headbox, a forming table, and one or more presses. The headbox allows the paper pulp to be discharged in a controlled and homogeneous manner onto the forming table for drainage (E62). The forming table includes a forming cloth that carries the pulp and allows the water to drain (E62), table rollers that guide and tension the forming cloth, and suction boxes that draw water from the paper pulp. The press(s) remove the water from the paper pulp by compression. The press(s) may include press felts, press rollers, suction boxes, etc.

[0087] Where appropriate, the process for manufacturing a roll of paper described above may include a step of diluting the paper pulp obtained by means of the paper pulp preparation process as described above, in order to obtain the desired dry fiber concentration before feeding E61 into the headbox.

[0088] The progressive E62 draining of the paper pulp can be carried out on a flat forming table.

[0089] The E63 drying of the paper pulp can be carried out in a press and drying section. The E63 drying process stabilizes the paper pulp into a continuous strip of paper.

[0090] The winding E64 of the paper strip can be carried out using a winder, in order to form the paper roll.

[0091] Any purification steps E30 and / or the addition of an additive E40 take place after refining E20 and before feeding the headbox with the paper pulp E61. One or more additional refining steps may take place after purification E30 and before feeding the headbox with the paper pulp E61.

[0092] The paper roll preparation process may further include a step of applying at least one E65 functional layer to the drained and dried paper pulp, or coating. Applying at least one E65 functional layer improves the properties of the paper obtained from the drained paper pulp. A functional layer may, for example, include a starch layer, a barrier layer, a sealing layer, and / or a micro-pigmented layer. In particular, one or more barrier layers may be applied (E65) to protect the paper against water, grease, oil, and / or oxygen.

[0093] The step of applying at least one functional layer E65 can be carried out inline, i.e., without interrupting the manufacturing process, so as to optimize the production of the paper roll. Thus, and as illustrated by way of non-limiting example in [Fig. 4], the step of applying at least one functional layer E65 can be carried out after the drying step E63, and the process may further include an additional drying step E66 of the paper pulp, the additional drying E66 occurring after the application E65 of the functional layer and before the winding E64 of the paper web onto the core. In particular, the functional layer is applied E65 to the paper web, then the paper web is dried again during the additional drying step E66, and finally the paper web is wound E64 onto the core.

[0094] Alternatively or in addition, the step of applying at least one functional layer E65 can be carried out offline. In this case, and as illustrated by way of non-limiting example in [Fig. 5], the process may further include an unwinding step E67 of the paper web carried out after the winding step E64, then the step of applying at least one functional layer E65, then an additional drying step E68, then an additional winding step E69 of the paper web onto a core so as to obtain a paper roll.

[0095] The step of applying at least one functional layer E65 can be carried out on only one of the two faces, or alternatively on both faces, of the paper strip.

[0096] A method for manufacturing a sheet of paper includes obtaining a roll of paper by means of the process described above, and cutting the roll of paper so as to obtain the sheet of paper. Paper pulp, paper, packaging

[0097] Paper pulp can be obtained by means of a paper pulp preparation process as described above. The described paper pulp is thus obtained in a simpler, less expensive, and less environmentally friendly way, compared to a conventional process.

[0098] The paper pulp comprises a refined mixture of a mass percentage of a fibrous by-product 10, such as coffee husks or textile dust, with a complementary mass percentage of cellulosic pulp 20. The paper pulp may comprise a mass percentage of fibrous by-product 10 of between 10% and 60%, for example between 20% and 50%, for example between 30% and 40%.

[0099] Paper pulp can have a Schopper-Riegler degree between 55 °SR and 100 °SR, for example between 65 °SR and 85 °SR, for example between 70 °SR and 80 °SR, for example approximately 77 °SR. Such Schopper-Riegler degree ranges correspond to good physical properties of the paper pulp, particularly for molding (E51) and drying (E52) to manufacture the molded cellulose object, or for draining (E62) to produce the paper web and then the paper.

[0100] A paper, in particular a wrapping paper, can be obtained by means of a paper roll preparation process as described above, with the advantages described above.

[0101] The basis weight of paper corresponds to the ratio between the weight and the surface area of ​​the paper. The basis weight can be measured using any suitable device, for example, a 100 cm² circular saw. Paper obtained by the process described above can have a basis weight of between 10 g / m² and 50 g / m², for example, between 20 g / m² and 40 g / m², or between 18 g / m² and 25 g / m². Such basis weights give the paper good mechanical properties and ease of handling for the user, and allow for a variety of uses for the paper, for example, for different types of packaging.

[0102] The paper may have a thickness of between 40 and 60 micrometers.

[0103] The tensile strength of a paper represents the tensile force required to Paper breakage. Tensile strength can be measured by any suitable device, for example, a vertical dynamometer. Paper can exhibit a tensile strength measured in the longitudinal direction of the paper between 2 daN / 30 mm and 8 daN / 30 mm, for example, between 5 daN / 30 mm and 6 daN / 30 mm. Paper can exhibit a tensile strength measured in the lateral direction of the paper between 1 daN / 30 mm and 5 daN / 30 mm, for example, between 2 daN / 30 mm and 4 daN / 30 mm, for example, between 2.5 daN / 30 mm and 3.5 daN / 30 mm. Such tensile strength ranges ensure good paper resistance for its end use and converting processes.

[0104] The paper may have a tear resistance measured in the longitudinal direction of the paper of between 150 mN and 250 mN, for example between 180 and 220 mN. The paper may have a tear resistance measured in the lateral direction of the paper of between 150 mN and 250 mN, for example between 180 and 220 mN.

[0105] The paper may have a differentiating visual appearance, for example with fragments of coffee film or textile dust having a different shade from the rest of the paper, while maintaining satisfactory homogeneity.

[0106] Packaging may include wrapping paper as described above or a molded cellulose object obtained by means of a molded cellulose object preparation process as described above.

[0107] Although the present exposition has been made with reference to specific embodiments, modifications and changes may be made to these examples without departing from their general scope. In particular, individual features of the various embodiments illustrated / mentioned may be combined in additional embodiments.

Claims

Demands

1. A process for preparing paper pulp, comprising the following steps: - mixing (E10) a mass percentage of a fibrous by-product (10) with a complementary mass percentage of a cellulosic pulp (20), wherein the fibrous by-product (10) comprises at least one of the following: coffee husk from roasting coffee beans, the coffee husk comprising a mass percentage of water-soluble compounds greater than 15% and a mass content of water less than 20%, and textile dust having a length of less than 5 mm; and - refining (E20) the mixture to obtain the paper pulp.

2. A process according to claim 1, wherein the cellulosic pulp (20) is obtained from cooking at least one of the following fibers: a wood fiber, an annual plant fiber.

3. A process according to claim 1 or claim 2, wherein the mass percentage of fibrous by-product (10) in the mixture is between 10% and 60%, for example is between 20% and 40%.

4. A method according to any one of claims 1 to 3, wherein the coffee film has an average surface area of ​​less than 2 cm2, or even less than 1.5 cm2.

5. A method according to any one of claims 1 to 4, wherein at least 95% of the fibers present in the textile dust have a length of less than 3 mm.

6. A process according to any one of claims 1 to 5, wherein, during the refining step (E20), the paper pulp is refined so as to have a Schopper-Riegler degree between 55 °SR and 100 °SR, for example between 65 °SR and 85 °SR.

7. A process according to claim 2, wherein the cellulosic pulp (20) is obtained by cooking at least one fiber from an annual plant, the process further comprising at least one pre-mixing step (E10) from among cooking (E11), peeling (E2), washing (E3) and bleaching (E4) of the annual plant fiber in order to obtain the cellulosic pulp (20).

8. A process according to any one of claims 1 to 7, further comprising a post-refining step (E20) of purifying (E30) the paper pulp.

9. A process according to any one of claims 1 to 8, further comprising a post-refining step (E20) of adding an additive (E40) to the paper pulp, the additive comprising at least one of a retention agent, a dry strength agent, a wet strength agent, a sizing agent, mineral fillers, a colorant.

10. A process for preparing a molded cellulose object, comprising the following steps: - preparing paper pulp by means of a process according to any one of claims 1 to 9; - molding (E51) the paper pulp; and - drying (E52) the molded paper pulp so as to obtain a molded cellulose object.

11. A method for preparing a paper roll, comprising the following steps: - preparing paper pulp by means of a method according to any one of claims 1 to 9; - feeding (E61) a headbox of a paper machine with the paper pulp; - progressively draining (E62) the paper pulp on a forming table; - drying (E63) the drained paper pulp so as to obtain a paper strip; and - winding (E64) the paper strip onto a mandrel so as to obtain a paper roll.

12. A process according to claim 11, further comprising a step of applying at least one functional layer (E65) to the drained and dried paper pulp, for example among a starch layer, a barrier layer, a sealing layer, a micro-pigmented layer.

13. Paper pulp prepared by means of the process according to any one of claims 1 to 9, wherein the paper pulp has a Schopper-Riegler degree between 55 °SR and 100 °SR, for example between 65 °SR and 85 °SR.

14. Packaging paper obtained by means of the process according to claim 11 or claim 12, wherein the packaging paper has a basis weight of between 10 g / m2 and 50 g / m2, for example between 18 g / m2 and 25 g / m2.

15. Packaging comprising wrapping paper according to claim 14 or a molded cellulose object obtained by means of a process according to claim 10.

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