Coated fibrous WEBS and sheets and uses thereof

Abstract

According to an example aspect, there is provided a coated fibrous web or sheet comprising: a fibrous layer, containing 95 to 65 % of wood pulp fibers and 5 to 35 % of man-made fibers, calculated from the total weight of the fibers of the fibrous layer, and a binder component in an amount of 01 to 15 %, calculated from the total weight of the fibers of the fibrous layer, wherein the man-made fibers have a fiber length of at least 4 mm and the binder component comprises a binder selected from emulsion-polymers, and a coating layer at least on one side of the fibrous layer, wherein the coated fibrous web or sheet has a grammage of 120 to 180 g / m2, a caliper of 180 to 230 µm and a cross-directional tear strength of at least 2700 mN.

Description

COATED FIBROUS WEBS AND SHEETS AND USES THEREOFFIELD

[0001] The present invention relates to fibrous webs and sheets. In particular, the present invention relates to coated fibrous webs and sheets which comprise a fibrous layer formed by a mixture of wood pulp fibers and man-made fibers, and which further contains a binder component. The present invention also relates to tags for attachment to packages.BACKGROUND

[0002] Tags for outdoor and indoor cold products, including net packages for fruits and vegetables, are typically shaped as elongated labels with a first portion comprising a narrow strip that is to be mechanically attached to the packages by staples or metal clips, and an adjacent second portion that exhibits at least one printed surface for identification purposes. To avoid the tag from being tom off during processing and transport of the product, the material used needs to have, in combination, good tensile strength and, in particular, excellent tear strength. Further, the tag needs to have proper moisture resistance.

[0003] So far, tags of the above kind have conventionally been manufactured from substrates of plastic materials, such as polypropylene. To meet the requirement of printability, for example by direct thermal printing, the tags typically have a separate layer of thermal paper laminated onto the substrate. Lamination impairs recyclability of the tags.

[0004] There is a need for replacing plastics and laminates with recyclable materials that can be obtained from renewable sources, such as cellulosic materials, and that can be readily produced as reasonably thin, but mechanically strong, smooth webs and sheets with at least one printable surface, while avoiding lamination.SUMMARY

[0005] It is an aim of the present technology to address problems of the art by providing a fibrous web or sheet, for example in the form of a fibrous monolayer, that can be produced in a web-forming step and has good mechanical properties. The fibrous web or sheet can further comprise, on at least one side thereof, a coating layer that is capable of being printed.

[0006] In a first aspect, there is provided a fibrous web or sheet comprising:- a fibrous layer, containing 95 to 65 % of wood pulp fibers and 5 to 35 % of manmade fibers, calculated from the total weight of the fibers, and a binder component in an amount of 0.1 to 15 %, calculated from the total weight of the fibers, wherein the man-made fibers have a fiber length of at least 4 mm and the binder component comprises a binder selected from emulsion-polymers,wherein the fibrous web or sheet has a grammage of 120 to 180 g / m2, a caliper of 180 to 230 pm and a cross-directional tear strength of at least 2700 mN.

[0007] In a second aspect, there is provided a coated fibrous web or sheet comprising:- a fibrous layer, containing 95 to 65 % of wood pulp fibers and 5 to 35 % of manmade fibers, calculated from the total weight of the fibers, and a binder component in an amount of 0.1 to 15 %, calculated from the total weight of the fibers, wherein the man-made fibers have a fiber length of at least 4 mm and the binder component comprises a binder selected from emulsion-polymers, and- a coating layer at least on one side of the fibrous layer,wherein the coated fibrous web or sheet has a grammage of 120 to 180 g / m2, a caliper of 180 to 230 pm and a cross-directional tear strength of at least 2700 mN.

[0008] In a third aspect, there is provided a tag for attachment to a package, in particular to packages for fruits and vegetables, or for use in the shape of a band, such as a wrist band, comprising the coated fibrous web or sheet according to the second aspect.

[0009] More specifically, the present invention is characterized by what is stated in the characterizing portions of the independent claims.

[0010] Considerable advantages are obtained by the present technology. Thus, the present coated fibrous webs or sheets may be readily obtained by coating of, for example, wet-laid fibrous layers produced in, e.g., a single, web or sheet forming step. The present coated fibrous webs or sheets typically exhibit excellent tear strength and good tensile strength. Further, the fibrous layer generally has excellent bulk and good opacity and moisture resistance.

[0011] One or both opposite sides of the fibrous layer may be coated, in particular with a coating composition containing a mineral pigment. The coated side of the fibrous webor sheet may provide a smooth surface which can be subjected to printing, for example by direct thermal printing.

[0012] Furthermore, the present fibrous webs or sheets may have a sufficient mechanical strength to enable their use as blanks in the manufacture of tags with narrow strips that can be mechanically attached to packages without significant risk that the tags are torn away during normal handling of the packages in indoor and outdoor conditions. Other potential uses of the present fibrous webs or sheets are as blanks for short term labels, receipts and tickets.

[0013] One or more embodiments may comprise one or more features from the following itemized list:• the wood pulp fibers form a fibrous matrix into which the man-made fibers are interspersed• the matrix exhibits a first bonding strength between the wood pulp fibers forming the matrix and a second bonding strength between the wood pulp fibers of the matrix and the man-made fibers• the first bonding strength being greater than the second bonding strength• the man-made fibers have a tensile strength greater than the second bonding strength • the man-made fibers have a tensile strength of 250 MPa or more• the fibrous web or sheet comprises a further fibrous layer between said fibrous layer and the coating layer• the said further fibrous layer contains 80 to 100 % of wood pulp fibres and 0 to 20 % of man-made fibres, calculated from the total weight of the fibres of the further fibrous layer• the binder component comprises at least a first binder selected from emulsion- polymers and mixtures thereof, and a second binder selected from water-soluble polymers and mixtures thereof• the first binder for example being selected from the group of acrylic latexes and styrene butadiene dispersions• the binder component comprises 0.1 to 20 % by weight, in particular 1 to 15 % by weight, for instance 2 to 10 % by weight, of an acrylic or styrene butadiene emulsion polymer or a mixture of such polymers, the percentages being calculated from the total weight of the binder component• the binder component comprises 0.01 to 6 % by weight, in particular 0.1 to 5 % by weight, for instance 0.2 to 4 % by weight, of a water-soluble polymer or water- soluble polymers, the percentages being calculated from the total weight of the binder component• the binder component comprises the first binder selected from emulsion-polymers and mixtures thereof• the binder component comprises the second binder selected from water-soluble polymers and mixtures thereof• a weight ratio of the first binder and the second binder is 1:10 to 10:1, in particular 1:5 to 5:1 or 1:2 to 2:1, calculated based on the dry matter of the polymers• the first binder is selected from acrylic dispersions containing styrene and acrylonitrile• the second binder is a water-soluble homo- or copolymer or a mixture of thereof • the second binder is selected from polyvinyl alcohols, polyvinyl acetate dispersions, ethyl vinyl alcohol dispersions and polyurethane dispersions and combinations thereof, for example aqueous copolymer dispersions based on vinyl acetate and ethylene• the second binder comprises 0.1 to 10 % by weight of polyvinyl alcohol or polyvinyl acetate dispersions or both, calculated from the total weight of the binder• the coated fibrous web or sheet exhibits a bulk of 110 to 150 cm3 / g, such as 115 to 145 cm3 / g, of the fibrous layer• the wood pulp fibers are selected from the group of chemical pulp fibers, recycled fibers, mechanical pulp fibers, semi-mechanical pulp fibers, and combinations thereof• at least 50 %, in particular at least 60 %, for example 75 to 100 %, by weight of the wood pulp fibers are chemical pulp fibers, any remainder of wood pulp fibers being selected from the group of recycled fibers, semi-mechanical pulp fibers and mechanical fibers and combinations thereof• at least 50 % of the wood pulp fibers are unrefined, bleached or both• the man-made fibers are selected from the group of regenerated cellulose fibers, and polylactide fibers and combinations thereof• the regenerated cellulose fibers are selected from the group of viscose fibers, modal fibers, rayon fibers, lyocell fibers, ioncell fibers and carbamate fibers and mixturesthereof, and the natural fibers are selected from the group of annual and perennial plant fibers and combinations thereof• man-made fibers are fibers derived from the group of straws of grain crops, wheat straw, reed canary grass, reeds, flax, hemp, kenaf, jute, ramie, seed, sisal, abaca, coir, bamboo, bagasse, cotton kapok, milkweed, pineapple, cotton, rice, reed, esparto grass, Phalaris cirundinacea. seed hair fibers, leaf fibers, bast fibers, and combinations thereof• the man-made fibers have a length of 4 to 50 mm, in particular 5 to 25 mm, and a thickness of 0.5 to 20 dtex, such as 1 to 15 dtex or 1.5 to 10 dtex• the fibrous matrix is capable of at least partially disintegrating in an aqueous medium, for example at a temperature of 10 to 95 °C and a pH of 1 to 12, for example a temperature of 20 to 75 °C and a pH of 2 to 10 or a temperature of 25 to 60 °C and a pH of 6 to 8, so that at least a part of the man-made fibers is released from the fibrous matrix• the coating layer has a weight of 1 to 10 g / m2, in particular 2.5 to 7.5 g / m2, for example 3 to 6 g / m2• the coating layer is formed by a coating binder and a coating pigment, for example a plate-like pigment, in particular talc or kaolin• the coated fibrous web or sheet has a grammage of 140 to 160 g / m2, a caliper of 200 to 220 pm and a CD tear strength of at least 2750 mN• the fiber orientation of the fibrous layer, as defined by the ratio of a machine direction orientation to a cross direction orientation, is greater than 1 and up to 10, and in particular greater than 1 and up to about 5, typically 1.1 to 3, for example 1.5 to 2 • the fibrous layer is essentially free from fillers, such as mineral fillers• the coated fibrous web or sheet is obtained by wet-laying or foam-forming

[0014] Further features of preferred embodiments of the present technology will be discussed in more detail with the aid of the following detailed description.BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIGURE 1 shows a schematic cross-sectional view of a coated fibrous web according to one embodiment; and

[0016] FIGURE 2 shows a top view of a tag according to one embodiment.EMBODIMENTSDefinitions

[0017] As used herein, the term “about” refers to a value, which is ±5% of the stated value. The term “essentially free”, unless otherwise states, means that there is at most 1% of the component the item is essentially free of.

[0018] Any percentages that are not absolute percentages are weight-percentages. Unless otherwise stated herein or clear from the context, any percentages referred to herein are expressed as percent by weight based on a total weight of the respective composition.

[0019] Unless otherwise stated, properties that have been experimentally measured or determined herein have been measured or determined at room temperature. Unless otherwise indicated, room temperature is 25 °C.

[0020] Unless otherwise stated, properties that have been experimentally measured or determined herein have been measured or determined at atmospheric pressure. Unless otherwise indicated, atmospheric pressure is 101.325 kPa.

[0021] In the present application, the term “fiber length” refers to length weighted fiber length, unless otherwise indicated.

[0022] The present technology provides fibrous webs and sheets that are formed by a generally planar fibrous layer comprising wood pulp fibers, man-made fibers and a binder component and which fibrous layer can be coated on either or both sides with a coating layer comprising a coating pigment and a coating binder for the pigment.

[0023] “Web” stands for a continuous length of planar material and “sheet” for a discrete piece of planar material.

[0024] In the present context, the fibrous layer can be characterized as a “monolayer”, as opposed to laminated structures that comprise overlapping fibrous layers joined by intermediate adhesive layers. The fibrous layer can have a first side and an opposite second side. The fibrous layer may be coated on either or both sides with coating layer(s).

[0025] In one embodiment, the fibrous layer or the fibrous web or sheet of the present kind is manufactured by wet-laying or foam forming in one web or sheet forming process step using a single- or multilayer headbox.

[0026] In the present context, the term “binder component” covers both one binder (a single-binder composition) and mixtures of two or more binders (a multi-binder composition).

[0027] The present coated fibrous webs or sheets are generally recyclable.

[0028] In the present context, the term “man-made fibers” stands for fibers of synthetic or, in particular, natural raw-material which have been subjected to industrial processing for example by spinning or moulding to produce continuous threads, which can be cut to predetermined fiber length. Examples of man-made fibers include in particular regenerated cellulosic fibers, such as viscose fibers, modal fibers, rayon fibers, lyocell fibers and ioncell fibers and fibers of cellulosic derivatives, such as carbamate fibers.

[0029] The “fiber length” of the man-made fibers is given as length weighted fiber length.

[0030] In one embodiment, the term “recyclable” implies that the coated fibrous webs or sheets are water dispersible. “Water dispersible”, when used in connection of the present materials, means that the fibrous matrices can be broken up and at least a part of the wood pulp fibers or the man-made fibers or both can be separated from the materials and, optionally, from each other. Thus, at least a portion, e.g., at least 5 %, in particular at least 10 %, suitably at least 20 % by weight of the wood pulp fibers, or 5 %, in particular at least 10 %, suitably at least 20 % by weight of the man-made fibers, or both, can be recovered and optionally recycled.

[0031] In one embodiment, the term “recyclable” implies that the coated fibrous webs and sheets can be composted or otherwise reused as biodegradable waste.

[0032] In one embodiment, the term “recyclable” implies that a part of the wood pulp fibers or the man-made fibers or both can be separated from the present coated fibrous web or sheet and, optionally, from each other, and recovered and optionally recycled by industrial processes, and a part of the present materials are composted or otherwise reused as biodegradable waste.

[0033] In the present context, “CD” or “Cross-Directional” tear strength can be measured by the TAPPI Elmendorf testing method T414 (Internal tearing resistance of paper).

[0034] Tensile Strength can be measured by ASTM Cl 557; Caliper by TAPPI Test Method T411; and Surface Roughness by ISO 8791 / 2 and 8791 / 4.

[0035] “MD” stands for machine direction and “CD” stands for cross direction.Embodiments

[0036] In one embodiment, the fibrous layer of the present coated webs and sheets comprises 95 to 65 % of wood pulp fibers and 5 to 35 % of man-made fibers, calculated from the total weight of the fibers, and a binder component in an amount of 0.01 to 15 %, calculated from the total weight of the fibers, wherein the man-made fibers have a fiber length of at least 4 mm and wherein the binder component comprises a binder selected from emul si on-poly mers .

[0037] In one embodiment, the coated fibrous web or sheet comprises:- a fibrous layer, containing 95 to 65 % of wood pulp fibers and 5 to 35 % of manmade fibers, calculated from the total weight of the fibers, and a binder component in an amount of 0.1 to 15 %, calculated from the total weight of the fibers, wherein the man-made fibers have a fiber length of at least 4 mm and the binder component comprises a binder selected from emulsion-polymers, and- a coating layer at least on one side of the fibrous layer,wherein the coated fibrous web or sheet has a grammage of 120 to 180 g / m2, a caliper of 180 to 230 pm and a cross-directional tear strength of at least 2700 mN.

[0038] In one embodiment, the wood pulp fibers form a matrix into which the manmade fibers are interspersed. The cellulose fibers of the matrix are bonded together with a first bonding strength, whereas the wood pulp fibers of the matrix and the man-made fibers are bonded to each other with a second bonding strength. Typically, the first bonding strength is greater than the second bonding strength, in particular the first bonding strength is at least 10 %, in particular at least 15 %, for example at least 20 % greater than the second bonding strength.

[0039] In one embodiment, the man-made fibers have a tensile strength greater than the second bonding strength, in particular the man-made fibers have a tensile strength of 250 MPa or more.

[0040] In one embodiment, the fiber orientation of the fibrous layer, as defined by the ratio of machine direction (abbreviated “MD”) to cross direction (abbreviated “CD”), is greater than 1 and up to 10, and in particular greater than 1 and up to about 5, typically 1.1 to 3, for example 1.5 to 2.

[0041] It would appear that when the fibrous layer of the present coated webs and sheets is subjected to mechanical forces, some of the energy of the mechanical forces exerted on the fibrous layer will be taken up by or converted into movement of the man-made fibers within the matrix. Such movement may contribute to the excellent mechanical properties, in particular a CD tear strength of at least 2700 mN, of the coated fibrous web or sheet, although this is merely one possibility and the scope of the present invention is not limited to that explanation. At the same time, the tensile strength, in particular MD tensile strength, meets the requirements of many fields of application.

[0042] In some embodiments, at least 50 %, such as at least 60 %, such as at least 80 % of the total weight of the fibrous layer consists of wood pulp fibres and man-made fibres.

[0043] The wood pulp fibers of the fibrous layer are typically selected from the group of chemical pulp fibers, recycled fibers, regenerated fibers, mechanical pulp fibers, semimechanical pulp fibers, and combinations thereof. In one embodiment, at least 50 %, in particular at least 60 %, for example 75 to 100 %, by weight of the wood pulp fibers are chemical pulp fibers, any remainder of wood pulp fibers being selected from the group of recycled fibers, regenerated fibers, semi-mechanical pulp fibers and mechanical fibers and combinations thereof.

[0044] In one embodiment, the wood pulp fibers are selected from bleached and nonbleached, refined and unrefined, in particular unrefined chemical fibers or mixtures of unrefined and refined chemical pulp fibers. For example, the wood pulp fibers are selected from mixtures containing 50 to 95 % by weight of unrefined chemical pulp fibers and 5 to 50 % by weight of refined chemical pulp fibers, the percentages being calculated from the total weight of the mixture of unrefined and refined chemical pulp fibers.

[0045] In one embodiment, at least 50 % by weight of the wood pulp fibers are chemical pulp fibers that are unrefined or bleached or both.

[0046] The wood pulp fibers are typically obtained from wood material. Examples of wood species from which the wood material can be obtained include hardwood, such asbirch, beech, aspen, such as European aspen, alder, eucalyptus, maple, acacia, and mixed tropical hardwood, and softwood pine, such as loblolly pine, fir, hemlock, larch, spruce such as Black spruce or Norway spruce, and mixtures of two or more of the wood species thereof.

[0047] In one embodiment, the wood pulp fibers comprise a blend of softwood and hardwood fibers.

[0048] The fibrous web or sheet may comprise only a single fibrous layer or it may comprise several fibrous layers.

[0049] In one embodiment, the fibrous layer comprises softwood fibers mixed with man-made fibers interspersed throughout said layer, and the fibrous layer forms a base layer onto which further fibrous layers may be arranged. For example, a further fibrous layer comprising hardwood fibers, such as birch or eucalyptus, may be arranged on one or both sides of the fibrous layer to render the surface a predetermined smoothness.

[0050] In one embodiment, the coated fibrous web or sheet comprises an intermediate layer between the fibrous layer and the coating layer. The intermediate layer preferably consists of a further fibrous layer.

[0051] The further fibrous layer may comprise wood pulp fibres, such as hardwood fibres. In an embodiment, the further fibrous layer contains 80 to 100 % of wood pulp fibres and 0 to 20 % of man-made fibres, calculated from the total weight of the fibres of the further fibrous layer.

[0052] In some embodiments, at least 50 %, such as at least 80 %, such as at least 90% of the total weight of the further fibrous layer consists of wood pulp fibres.

[0053] The types and amounts of fibres may be different or alternatively the same in the fibrous layer and in the further fibrous layer(s).

[0054] The further fibrous layer may comprise, independently from the fibrous layer, a binder component, for example in an amount of 0.1 to 15 %, calculated from the total weight of the fibres of the further fibrous layer. The fibrous layer and the further fibrous layer(s) may be impregnated together with the binder component before the coating layer is applied.

[0055] FIGURE 1 shows a schematic cross sectional view a coated fibrous web according to one embodiment. The coated fibrous web comprises a fibrous layer 1. The coating layers 3, 4 are provided on both sides of the fibrous layer 1. Additionally, the coated fibrous web comprises an intermediate layer 2 (a further fibrous layer) between the fibrous layer 1 and the coating layer 3.

[0056] The man-made fibers of the fibrous layer are typically selected from the group of regenerated cellulose fibers, and polylactide fibers and combinations thereof.

[0057] In one embodiment, the regenerated cellulose fibers are selected from the group of viscose fibers, modal fibers, rayon fibers, lyocell fibers, ioncell fibers and carbamate fibers and mixtures thereof, and the natural fibers are selected from the group of annual and perennial plant fibers and combinations thereof.

[0058] In one embodiment, the regenerated fibers are selected from viscose fibers, lyocell fibers and combinations thereof.

[0059] In one embodiment, the regenerated fibers are viscose fibers.

[0060] In one embodiment, the man-made fibers are fibers derived from the group of straws of grain crops, wheat straw, reed canary grass, reeds, flax, hemp, kenaf, jute, ramie, seed, sisal, abaca, coir, bamboo, bagasse, cotton kapok, milkweed, pineapple, cotton, rice, reed, esparto grass, Phalaris cirundinacea. seed hair fibers, leaf fibers, bast fibers, and combinations thereof.

[0061] In one embodiment, the man-made fibers have a length of 4 to 50 mm, in particular 5 to 25 mm.

[0062] In one embodiment, the man-made fibers have a thickness, also referred to as “linear density” or “length per unit mass”, of 0.5 to 20 dtex, such as 1 to 15 dtex or 1.5 to 10 dtex.

[0063] In one embodiment, the man-made fibers comprise mixtures of fibers of different dimensions and origins. For example, the man-made fibers may comprise manmade staple fibers having a length of 5 to 25 mm mixed with man-made staple or natural fibers having a length of 10 to 40 mm.

[0064] In general, the fibrous layer may contain up to 35 % by weight of man-made fibers, calculated from the total weight of the fibers of the fibrous layer.

[0065] As mentioned above, the binder component may comprise several binders. In one embodiment, the binder component comprises at least a first binder selected from emulsion-polymers and mixtures thereof and a second binder selected from water-soluble polymers and mixtures thereof. The first binder is, for example, selected from the group of acrylic latexes and styrene butadiene dispersions.

[0066] In one embodiment, the binder component comprises 0.1 to 20 % by weight, in particular 1 to 15 % by weight, for instance 2 to 10 % by weight, of an acrylic or styrene butadiene emulsion polymer or a mixture of such polymers, and 0.01 to 6 % by weight, in particular 0.1 to 5 % by weight, for instance 0.2 to 4 % by weight, of a water-soluble polymer or water-soluble polymers, the percentages being calculated from the total weight of the binder component.

[0067] In one embodiment, the binder component comprises a first binder selected from emulsion-polymers and mixtures thereof, and a second binder selected from water-soluble polymers and mixtures thereof, at a weight ratio of 1 : 10 to 10: 1, in particular 1 :5 to 5: 1 or 1 :2 to 2:1, calculated based on the dry matter of the polymers.

[0068] In one embodiment, the binder component comprises the first binder which is selected from acrylic dispersions containing styrene and acrylonitrile.

[0069] In one embodiment, the binder component comprises the second binder which is selected from water-soluble homo- and copolymers and mixtures thereof. In particular, the second binder may be selected from the group of polyvinyl alcohols, polyvinyl acetate dispersions, ethyl vinyl alcohol dispersions and polyurethane dispersions and combinations thereof, for example the second binder can be an aqueous copolymer dispersion containing vinyl acetate and ethylene.

[0070] In one embodiment, the second binder comprises 0.1 to 10 % by weight, for example about 1 to 8 % by weight of polyvinyl alcohol or polyvinyl acetate dispersions or both, calculated from the total weight of the binder.

[0071] It would appear, but this is merely one possibility and the present technology is not limited to the finding, that the presence of a water-soluble binder will influence the bonding of the man-made fibers to the fibrous matrix of the wood pulp fibers.

[0072] The present material can be produced by wet-laying or foam-forming.

[0073] In one embodiment, a fibrous layer is produced by the steps of- forming an aqueous fibrous slush comprising 95 to 65 % of wood pulp fibers and 5 to 35 % of man-made fibers, calculated from the total weight of the fibers,- conducting the aqueous fibrous slush to a foraminous support, i.e. for example a conventional wire for wet laying,- draining liquid through the foraminous support to form a wet fibrous layer, and - drying and optionally calendering the wet fibrous layer to obtain the fibrous layer.

[0074] A binder component is incorporated, such as impregnated, into the fibrous layer. To that aim, in one embodiment, the aqueous phase comprises at least one binder or a mixture of binders, for example a first binder and a second binder. In one embodiment, the fibrous layer is finalized before, during or after drying by treating the surface of the fibrous layer with at least one binder or a mixture of binders. It is also possible to introduce the first binder into the aqueous phase and to treat the fibrous layer before, during or after drying with the second binder.

[0075] Typically, the amount of a binder component is 0.1 to 15 % by weight, in particular 1 to 10 % by weight, calculated from the total weight of the fibers.

[0076] In one embodiment, the above method is carried out on a paper or paperboard machine, or on a wet-laid non-woven machine, using a single- or multilayer former.

[0077] In one embodiment, the above method is carried out on a paper machine.

[0078] In one embodiment, the consistency of the aqueous fibrous slush is from 0.01 to 5 % by weight, in particular 0.1 to 2 % by weight.

[0079] The fibrous layer can also be prepared by foam forming. Such an embodiment comprises forming a wet fibrous layer from a dispersion of fibers in a foamed liquid. Typically, a pulp or fiber furnish is first prepared in a pulper, followed by dewatering. The fibers are then mixed with a foam or foamable liquid containing a surfactant and water to form a fiber dispersion in the form of a foam. The fiber-foam is deposited on a wire and themain portion of the liquid, which is essentially in the form of foam, is removed, e.g., by suction. Foam forming, optionally with suction, may be carried out as disclosed in US 10 906268.

[0080] In one embodiment, a fibrous layer is produced by the steps of:- forming a foamed dispersion by dispersing wood pulp fibers and man-made fibers in a foam or foamable liquid comprising water and at least one foaming agent to obtain a fiber-foam comprising 95 to 65 % of wood pulp fibers and 5 to 35 % of man-made fibers, calculated from the total weight of the fibers, and 0.1 to 20 % by weight, in particular 0.5 to 10 % by weight of at least one foaming agent, such as a surfactant, calculated from the total dry matter of the dispersion,- conveying the formed fiber-foam to a foraminous support,- draining liquid through the foraminous support to form a wet fibrous layer, and - drying and optionally calendering the wet fibrous layer to obtain the fibrous layer.

[0081] A binder component is incorporated, such as impregnated, into the fibrous layer. Thus, the foam or foamable liquid may comprise at least one binder; or the formed fibrous layer is finalized before, during or after drying by treating the surface of the fibrous layer with at least one binder. It is also possible to combine these two embodiments. Thus, in one embodiment, a first binder is fed into the aqueous phase a second binder is used for treating the fibrous layer before, during or after drying.

[0082] In an embodiment, the fiber-foam composition comprises 20 to 90 % by volume, in particular 20 to 80 % by volume, for example 55 to 75% by volume of gas, in particular air.

[0083] In one embodiment, the above method is carried out on a paper or paperboard machine provided with a foam former.

[0084] In one embodiment, the consistency of the aqueous fibrous slush is from 0.01 to 5 % by weight, in particular 0.05 to 3 % by weight, for example 0.1 to 2 % by weight.

[0085] After drying of the wet-laid or foam formed fibrous layer, in one embodiment the fibrous layer is subjected to calendering to modify its surface smoothness. Calendering can be carried out on-machine or off-machine at one or several calenders. In one embodiment, the surface (Bendtsen) roughness of the calendered layer is smaller than 150 ml / min, for example smaller than 140 ml / min, such as smaller than 130 ml / min.

[0086] After calendering, if any, the fibrous layer thus obtained is subjected to coating with a coating composition comprising at least one pigment and a coating binder, optionally in combination with dispersants and other chemical additives. The coating can be carried out with a blade, rod, air knife, gravure or curtain coater at one or several coating stations. In one embodiment, a first surface of the fibrous layer is coated with blade or air knife coater whereas an opposite second surface of the fibrous layer is coated with a gravure coater.

[0087] In embodiments in which the fibrous web or sheet comprises one or more further fibrous layers, all fibrous layers are preferably first formed in a single web forming step to obtain the fibrous web or sheet, and thereafter one or both sides of the fibrous web or sheet are coated with a coating composition.

[0088] The coating pigment can for example be selected from the group consisting of precipitated calcium carbonate, ground calcium carbonate, calcium sulphate, calcium oxalate, aluminium silicate, kaolin (hydrous aluminium silicate), aluminium hydroxide, magnesium silicate, talc (hydrous magnesium silicate), titanium dioxide and barium sulphate, and mixtures thereof. In particular, the pigment is a plate-like pigment, such as talc or kaolin.

[0089] In one embodiment, the fibrous layer is, after an optional calendering step, precoated with a binder, optionally provided with a pigment, to increase smoothness before coating.

[0090] The binders of the coating composition and the precoating composition can be selected from the group of starch, including cooked or cold soluble surface sizing starch slurry, polyvinyl alcohol, ethylene vinyl alcohol and mixtures thereof.

[0091] The dispersants and other chemical additives include dispersing agents, such as sodium salts of polyacrylic acid, viscosity -modifying agents, such as carboxymethyl or hydroxyethyl cellulose, polyacrylates, alginates and benzoate, hardeners for improving water repulsion, anti-foaming agents, pH adjusting agents, preservatives and slip agents.

[0092] In one embodiment, the coating composition comprises based on its dry weight 5 to 60 % of at least one pigment, such as talc or kaolin, and 95 to 40 % of binder, in particular it comprises based on its dry weight approximately 10 to 50 % mineral pigment and 90 to 50 % binder, for example 15 to 40 % mineral pigment and 85 to 60 % binder, possibly together with dispersion additives.

[0093] In one embodiment, a coating layer is applied on one side of the fibrous layer, in another embodiment, a coating layer is applied on two opposite sides of the fibrous layer. Typically, the coating layer has a weight of 1 to 20 g / m2, for example 2 to 15 g / m2, typically 1 to 10 g / m2, in particular 2.5 to 7.5 g / m2, for example 3 to 6 g / m2per side.

[0094] Coating of the fibrous layer will enhance its runnability on the paper machine. The coated surface(s) of the fibrous layer will provide printing surfaces. Various printing techniques can be used, as will be explained below.

[0095] In one embodiment, a coated web, produced on paper or paperboard machine or by equipment for non-woven materials, can be converted into sheets using conventional paper or paperboard converting equipment. Further conversion of the webs or sheets into intended final products, such as tags for packages, as will be discussed below, can be performed by conventional paper and paperboard conversion.

[0096] Generally, the grammage of the fibrous layer is about 110 to about 180 g / m2, typically in the range from about 120 to about 170 g / m2. One or both opposite sides of the fibrous layer exhibit a coating layer having a weight of 1 to 20 g / m2, for example 2 to 15 g / m2, typically 1 to 10 g / m2, in particular 2.5 to 7.5 g / m2, for example 3 to 6 g / m2per side.

[0097] The grammage of the further fibrous layer may be in the range 10 to 40 g / m2, such as 20 to 30 g / m2.

[0098] The total grammage of the coated web or sheet may be about 115 to about 185 g / m2, for example about 130 to about 170 g / m2or 140 to 160 g / m2.

[0099] The caliper of the coated web or sheet is typically in the range from about 180 to about 230 pm. In one embodiment, the caliper is about 200 to 220 pm.

[0100] In one embodiment, the bulk of the fibrous layer is about 110 to about 150 cm3 / g, such as 115 to 145 cm3 / g.

[0101] The present coated webs and sheets have a cross-directional (CD) tear strength of at least 2700 mN, in one embodiment about 2750 mN to 3700 mN, for example at least 2800 mN.

[0102] In one embodiment, the coated web or sheet has a grammage of 120 to 180 g / m2, a caliper of 180 to 230 pm and a CD tear strength of at least 2700 mN.

[0103] In one embodiment, the coated web or sheet has a grammage of 140 to 160 g / m2, a caliper of 200 to 220 and a CD tear strength of at least 2750 mN, such as 2800 mN or more.

[0104] The coated webs or sheets have good mechanical properties, including tensile and tear strengths as well as properties of stretch and opacity, and food contact is approved.

[0105] The coated webs or sheets are, even without lamination, suitable for conversion into tags for attachment to packages for outdoor and indoor cold products. The tags can be attached to packages, such as net packages for fruits, vegetables and root vegetables. The tags may be suitable for use in the shape of a band, such as a wrist band or as bands for strapping elongated products.

[0106] FIGURE 2 shows a top view of a tag according to one embodiment. The tag 11 comprises a first portion 12 adapted to be attached to a package, for example by gluing or, preferably, mechanically, and a second portion 13 adjacent to the first portion 12 having at least one printable surface 14.

[0107] The first portion 12 can be attached to a package with a mechanical fastening means 15. Generally, the fastening means 15 can be selected from the group of staples, plastic clips, metal clips, threads, strings, hooks and loop fasteners.

[0108] As shown in FIGURE 2, the first portion 12 is typically narrow, whereas the second portion 13 is broader than the first portion 12 to offer a larger surface for printing of the desired information of the content of the package to which the first portion 12 is to be attached.

[0109] As also shown in FIGURE 2, there can be two first portions 12, 16, each with fastening means 15, 17, for example for attaching the printable surface 14 by way of a girdle to the package.

[0110] In one embodiment, the second portion 13 comprises two opposite printable surfaces on the second portion. At least one surface is adapted to be printed with information identifying the content of the package to which it is adapted to be attached. On the same surface or on an opposite surface, information of supplier and on shelf-life can be provided.

[0111] The printing can be carried out, for example, by direct thermal printing or thermal transfer printing. In thermal printing, no inks, toners or ribbons are needed, whichmakes the printing method inexpensive to operate and it can be used for printing of the present material for use as short-term labels but also for receipts and tickets.

[0112] It is also possible to print opposite sides of the tag using different printing techniques. Thus, in one embodiment, a first surface (top side) of the fibrous web is formed by a fibrous layer rich in hardwood fibers, whereby the top side will - after coating - be capable of being printed using a roll-feed web printing process, such as Flexo printing, whereas an opposite surface (back side) of the fibrous web is formed by a fibrous layer rich in softwood fibers, whereby the back side will - after coating - be capable of being printed by thermal transfer printing.

[0113] The materials of the present fibrous webs or sheets, and tags and other products made from them, have good dimensional stability while, at the same time being typically recyclable, in particular by industrial processes. In one embodiment, the fibrous webs or sheets and articles produced from them, e.g., by paper or paperboard conversion, are capable of being disintegrated in a pulper, as conventionally used in the paper and paperboard industry, and at conditions used in recycling of paper, cardboard, and other fiber-based products. The pulping process may include chemicals, such as NaOH, H2O2, chelant, sodium silicate, and surfactants.

[0114] In one embodiment, the fibrous web or sheet is capable of dispersing in an aqueous medium, such as water, at a temperature of 10 to 95 °C at a pH in the range from 1 to 12, for example at a temperature of 20 to 80 °C at a pH of 2 to 10, or a temperature of 30 to 70 °C at a pH of 3 to 9, or a temperature of 40 to 60 °C at a temperature of 6 to 8, typically at a consistency of 1 to 50 wt-%, for example 2 to 40 wt-%, such as 3 to 30 wt-% or 5 to 20 wt-%, which consistency is applicable to any of the foregoing intervals.

[0115] In one embodiment, the fibrous web or sheet is pulped at a consistency of 2 to 7 wt-% and a temperature of 30 to 60 °C. In another embodiment the fibrous web or sheet is pulped at a consistency of 10 to 35 wt-% and a temperature of 30 to 60 °C, while the pH is maintained at 3 to 9.

[0116] Due to disintegration of the fibrous matrix during pulping, at least 5 %, for example at least 10 % or at least 15 %, preferably at least 20 % and in particular at least 25 % of the man-made fibers, calculated from the dry weight of the man-made fibers, will be released from the fibrous matrix formed by the wood pulp fibers and can be recovered and,potentially, recycled. Generally, about 30 to 95 % of the man-made fibers will be released during disintegration of the fibrous matrix. At least 50 % of the released man-made fibers can typically be recovered.

[0117] Typically, during disintegration at least of 5 %, for example at least 10 % or at least 15 %, preferably at least 20 % and in particular at least 25 % of the wood pulp fibers, calculated from the dry weight of the wood pulp fibers, of the fibrous matrix can be recovered and, potentially, recycled. Generally, about 30 to 99 %, for example 40 to 90 %, of the wood pulp fibers will be released during disintegration of the fibrous matrix, the percentages being calculated from the dry weight of the fibers. At least 50 % of the released wood pulp fibers, calculated from the dry weight of the wood pulp fibers, can typically be recovered,

[0118] In one embodiment, the wood pulp fibers and / or man-made fibers are separated from other components by coarse screening. The recovered fibers can be reused in the production of new consumer products, such as paper, paperboard or non-woven products.Example

[0119] A fibrous layer having a grammage of 145 g / m2was prepared from a blend of softwood kraft fibers and viscose fibers by wet laying. The blend comprised 80 wt-% kraft fibers and 20 wt-% viscose fibers. The viscose fibers had a length weighted fiber length of 8 mm. On the wet fibrous layer, 20 wt-%, calculated from the weight of the fibers, of an emulsion polymer Acronal mixed with polyvinyl alcohol Vinamul was evenly applied by spraying.

[0120] After drying, the fibrous layer was calendered.

[0121] On the top side of the calendered fibrous layer, a coating composition was applied using a rod coater. No suction was used. The coating composition comprised, in addition to water, a mixture of the same binders as used for the fibrous layer. Further, the coating composition contained talc pigment in an amount of 35 % by weight of the total weight of the solids of the coating composition. The solids content was 45 % by weight of the total weight of the composition. The dynamic viscosity at room temperature was 676 mPas (ASTM445, Anton Paar). The grammage of the dried coating on top of the fibrous layer was 5 g / m2.

[0122] The fibrous layer which was coated on one side had a grammage of 150 g / m2and a caliper of 210 pm. The tear strength (CD) was 2800 mN and tensile strength was 7.85 kN / m.

[0123] The fiber orientation of the fibrous layer, as defined by ratio of machine direction to cross direction was 1.55.

[0124] The obtained coated fibrous layer was used for printing and after conventional converting it was used as a tag which could be attached by staples to a net package of onions.

[0125] It is to be understood that the embodiments of the invention disclosed are not limited to the particular structures, process steps, or materials disclosed herein, but are extended to equivalents thereof as would be recognized by those ordinarily skilled in the relevant arts. It should also be understood that terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting.

[0126] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the description, numerous specific details are provided, such as examples of lengths, widths, shapes, etc., to provide a thorough understanding of embodiments of the invention.

[0127] The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of also un-recited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated. Furthermore, it is to be understood that the use of "a" or "an", i.e. a singular form, throughout this document does not exclude a plurality.INDUSTRIAL APPLICABILITY

[0128] The present fibrous web or sheet can be used as tags for outdoor and indoor cold products, bands and nets for fruits and vegetables, and wristbands.

Claims

CLAIMS:

1. A coated fibrous web or sheet comprising:- a fibrous layer, containing 95 to 65 % of wood pulp fibers and 5 to 35 % of manmade fibers, calculated from the total weight of the fibers of the fibrous layer, and a binder component in an amount of 0.1 to 15 %, calculated from the total weight of the fibers of the fibrous layer,wherein the man-made fibers have a fiber length of at least 4 mm and the binder component comprises a binder selected from emulsion-polymers, and- a coating layer at least on one side of the fibrous layer,wherein the coated fibrous web or sheet has a grammage of 120 to 180 g / m2, a caliper of 180 to 230 pm and a cross-directional tear strength of at least 2700 mN.

2. The coated fibrous web or sheet according to claim 1, wherein the wood pulp fibers form a fibrous matrix into which the man-made fibers are interspersed.

3. The coated fibrous web or sheet according to claim 2, wherein the matrix exhibits a first bonding strength between the wood pulp fibers forming the matrix and a second bonding strength between the wood pulp fibers of the matrix and the man-made fibers, the first bonding strength being greater than the second bonding strength.

4. The coated fibrous web or sheet according to claim 3, wherein the man-made fibers have a tensile strength greater than the second bonding strength, in particular the man-made fibers have a tensile strength of 250 MPa or more.

5. The coated fibrous web or sheet according to any of the preceding claims, comprising a further fibrous layer between said fibrous layer and the coating layer, wherein said further fibrous layer contains 80 to 100 % of wood pulp fibres and 0 to 20 % of man-made fibres, calculated from the total weight of the fibres of the further fibrous layer.

6. The coated fibrous web or sheet according to any of the preceding claims, wherein the binder component comprises at least a first binder selected from emulsion-polymers and mixtures thereof, and a second binder selected from water-soluble polymers and mixturesthereof, the first binder for example being selected from the group of acrylic latexes and styrene butadiene dispersions.

7. The coated fibrous web or sheet according to any of the preceding claims, wherein the binder component comprises 0.1 to 20 % by weight, in particular 1 to 15 % by weight, for instance 2 to 10 % by weight, of an acrylic or styrene butadiene emulsion polymer or a mixture of such polymers, and 0.01 to 6 % by weight, in particular 0.1 to 5 % by weight, for instance 0.2 to 4 % by weight, of a water-soluble polymer or water-soluble polymers, the percentages being calculated from the total weight of the binder component.

8. The coated fibrous web or sheet according to any of the preceding claims 6 to 7, wherein the binder component comprises the first binder selected from emulsion-polymers and mixtures thereof, and the second binder selected from water-soluble polymers and mixtures thereof, at a weight ratio of 1:10 to 10:1, in particular 1:5 to 5:1 or 1:2 to 2:1, calculated based on the dry matter of the polymers.

9. The coated fibrous web or sheet according to any of the preceding claims 6 to 8, wherein the first binder is selected from acrylic dispersions containing styrene and acrylonitrile.

10. The coated fibrous web or sheet according to any of the preceding claims 6 to 9, wherein the second binder is a water-soluble homo- or copolymer or a mixture of thereof.

11. The coated fibrous web or sheet according to any of the preceding claims 6 to 10, wherein the second binder is selected from polyvinyl alcohols, polyvinyl acetate dispersions, ethyl vinyl alcohol dispersions and polyurethane dispersions and combinations thereof, for example aqueous copolymer dispersions based on vinyl acetate and ethylene.

12. The coated fibrous web or sheet according to any of the preceding claims 6 to 11, wherein the second binder comprises 0.1 to 10 % by weight of polyvinyl alcohol or polyvinyl acetate dispersions or both, calculated from the total weight of the binder.

13. The coated fibrous web or sheet according to any of the preceding claims, exhibiting a bulk of 110 to 150 cm3 / g, such as 115 to 145 cm3 / g, of the fibrous layer.

14. The coated fibrous web or sheet according to any of the preceding claims, wherein the wood pulp fibers are selected from the group of chemical pulp fibers, recycled fibers, mechanical pulp fibers, semi-mechanical pulp fibers, and combinations thereof.

15. The coated fibrous web or sheet according to any of the preceding claims, wherein at least 50 %, in particular at least 60 %, for example 75 to 100 %, by weight of the wood pulp fibers are chemical pulp fibers, any remainder of wood pulp fibers being selected from the group of recycled fibers, semi-mechanical pulp fibers and mechanical fibers and combinations thereof.

16. The coated fibrous web or sheet according to any of the preceding claims, wherein at least 50 % of the wood pulp fibers are unrefined, bleached or both.

17. The coated fibrous web or sheet according to any of the preceding claims, wherein the man-made fibers are selected from the group of regenerated cellulose fibers and polylactide fibers and combinations thereof.

18. The coated fibrous web or sheet according to any of the preceding claims, wherein the regenerated cellulose fibers are selected from the group of viscose fibers, modal fibers, rayon fibers, lyocell fibers, ioncell fibers and carbamate fibers and mixtures thereof, and the natural fibers are selected from the group of annual and perennial plant fibers and combinations thereof.

19. The coated fibrous web or sheet according to any of the preceding claims, wherein the man-made fibers are fibers derived from the group of straws of grain crops, wheat straw, reed canary grass, reeds, flax, hemp, kenaf, jute, ramie, seed, sisal, abaca, coir, bamboo, bagasse, cotton kapok, milkweed, pineapple, cotton, rice, reed, esparto grass, Phalaris arundinacea. seed hair fibers, leaf fibers, bast fibers, and combinations thereof.

20. The coated fibrous web or sheet according to any of the preceding claims, wherein the man-made fibers have a length of 4 to 50 mm, in particular 5 to 25 mm, and a thickness of 0.5 to 20 dtex, such as 1 to 15 dtex or 1.5 to 10 dtex.

21. The coated fibrous web or sheet according to any of the preceding claims 2 to 20, wherein the fibrous matrix is capable of at least partially disintegrating in an aqueous medium, for example at a temperature of 10 to 95 °C and a pH of 1 to 12, for example a temperature of 20 to 75 °C and a pH of 2 to 10 or a temperature of 25 to 60 °C and a pH of 6 to 8, so that at least a part of the man-made fibers is released from the fibrous matrix.

22. The coated fibrous web or sheet according to any of the preceding claims, wherein the coating layer has a weight of 1 to 10 g / m2, in particular 2.5 to 7.5 g / m2, for example 3 to 6 g / m2.

23. The coated fibrous web or sheet according to any of the preceding claims, wherein the coating layer is formed by a coating binder and a coating pigment, for example a plate-like pigment, in particular talc or kaolin.

24. The coated fibrous web or sheet according to any of the preceding claims, having a grammage of 140 to 160 g / m2, a caliper of 200 to 220 pm and a CD tear strength of at least 2750 mN.

25. The coated fibrous web or sheet according to any of the preceding claims, where the fiber orientation of the fibrous layer, as defined by the ratio of a machine direction orientation to a cross direction orientation, is greater than 1 and up to 10, and in particular greater than 1 and up to about 5, typically 1.1 to 3, for example 1.5 to 2.

26. The coated fibrous web or sheet according to any of the preceding claims, wherein the fibrous layer is essentially free from fillers, such as mineral fillers.

27. The coated fibrous web or sheet according to any of the preceding claims, obtained by wet-laying or foam-forming.

28. A tag for attachment to packages, in particular to packages for fruits and vegetables, or for use in the shape of a band, such as a wrist band, comprising the coated fibrous web or sheet according to any of claims 1 to 27.

29. The tag according to claims 28, wherein the coated fibrous web or sheet exhibits a caliper of 200 to 220 pm, a CD tear strength of at least 2750 mN, and further has at least one printable surface adapted to be printed by thermal printing or thermal transfer printing.

30. The tag according to claim 28 or 29, comprising a first portion adapted to be attached to a package, for example by gluing or mechanically, and a second portion adjacent to the first portion having at least one printable surface.

31. The tag according to any of claims 28 to 30, wherein the first portion is adapted to be attached to a package with a mechanical fastening means selected from the group of staples, plastic clips, metal clips, threads, strings, hooks and loop fasteners.

32. The tag according to any of claims 28 to 31, comprising two opposite printable surfaces on the second portion of the tag.

33. The tag according to any of claims 28 to 32, comprising a surface printed with information identifying the content of the package to which it is adapted to be attached.

34. The tag according to any of claims 28 to 33, comprising the coated fibrous web or sheet according to any of claims 1 to 27 which has been calendered and has a roughness smaller than 140 ml / min.

Images