Spunlace entangled nonwoven comprising cellulosic filaments

Abstract

A spunlace entangled nonwoven comprising artificial cellulose filaments, natural cellulose fibers, and staple fibers. The staple fibers have a length of 10 mm to 20 mm. A wipe comprising a spunlace entangled nonwoven. A method of making a nonwoven in which a web of artificial cellulose filaments is provided and natural cellulose fibers and staple fibers are wet-formed on top of the web of artificial cellulose filaments, thereby forming a fibrous web comprising the artificial cellulose filaments, natural cellulose fibers and staple fibers. The fibrous web is then spunlaced entangled to form a nonwoven. A method of manufacturing a wipe.

Description

Technical Field

[0001] The present invention relates to spunlace nonwovens comprising synthetic cellulose filaments, wipes containing such spunlace nonwovens, methods of manufacturing nonwovens, and methods of manufacturing wipes. Background Technology

[0002] Absorbent nonwoven materials are commonly used for wiping up various spills and leaks in industrial, service, office, and home settings. There are many requirements for the manufacture of nonwoven materials for wiping purposes. An ideal wipe should be strong, absorbent, abrasion-resistant, and exhibit low linting. To meet these requirements, absorbent nonwoven materials typically include different types of fibers, such as combinations of filaments and staple fibers, and fibers from different sources, such as fossil-based plastic fibers and / or natural fibers. Following the desire for non-fossil or plastic-free materials, man-made cellulose fibers (often referred to as regenerated cellulose fibers) have been considered as components of absorbent nonwoven materials.

[0003] WO 2018 / 184042 discloses a nonwoven material for industrial cleaning wipes. This nonwoven material comprises a cellulose nonwoven web made of substantially pure cellulose formed from continuous filaments. The nonwoven material may include layers formed from substantially continuous filaments, pulp fibers, or short fibers, all layers subsequently hydroentangled together. A method for manufacturing a nonwoven material composed of substantially continuous cellulose filaments is also disclosed.

[0004] WO 2005 / 042819 discloses a hydroentangled nonwoven material comprising continuous filaments, natural fibers, and synthetic staple fibers. A method for manufacturing the nonwoven material is also disclosed. The method includes forming a fiber web of continuous filaments on a shaped fabric, applying a wet-formed fiber dispersion comprising synthetic staple fibers and natural fibers to the top of the continuous filaments, and subsequently hydroentangled the fiber web. Summary of the Invention

[0005] The purpose of this invention is to provide strength, particularly wet strength, for nonwoven materials comprising man-made cellulose fibers.

[0006] This objective, as well as other objectives that will be apparent to those skilled in the art upon studying this specification, is achieved by the hydroentangled nonwovens, wipes, and methods of the appended claims.

[0007] It has thus been found that short fibers with a length of 10 to 20 mm, preferably 10 to 15 mm, are advantageous for providing strength to hydroentangled nonwovens, including synthetic cellulose filaments and wood pulp fibers. A high ratio of wet tensile index to dry tensile index can therefore be obtained, although cellulose-based nonwovens typically have a much lower such ratio than nonwovens based on synthetic or fossil materials.

[0008] In a first aspect, the present invention relates to a hydroentangled nonwoven fabric comprising synthetic cellulose filaments, natural cellulose fibers and synthetic short fibers, wherein the length of the synthetic short fibers is 10 to 20 mm, preferably 10 to 15 mm.

[0009] Staple fibers are natural fibers or cut lengths derived from man-made filaments. Staple fibers used in nonwovens are typically 5 to 60 mm in length, such as 20 to 60 mm or 40 to 60 mm. Staple fibers also include those shorter than 20 mm or less than 15 mm (also called chopped strands). Filaments are typically very long fibers proportional to their diameter, and in principle, unlimited. Filaments include fibers that break as a result of filament breakage during manufacturing or web forming.

[0010] The spunlace nonwoven fabric may comprise 10 to 50% by weight of man-made cellulose filaments, 20 to 85% by weight of natural cellulose fibers, and 2.5 to 25% by weight of man-made staple fibers, the weight percentages being based on the total weight of the nonwoven fabric. Alternatively, the spunlace nonwoven fabric may comprise 15 to 35% by weight of man-made cellulose filaments, 40 to 75% by weight of natural cellulose fibers, and 5 to 20% by weight of man-made staple fibers, the weight percentages being based on the total weight of the nonwoven fabric.

[0011] Synthetic cellulose filaments can be formed from naturally sourced cellulose such as regenerated cellulose. Regenerated cellulose is obtained by converting natural cellulose into a soluble cellulose derivative and subsequently regenerating the cellulose, typically forming fibers or filaments. Examples of regenerated cellulose are rayon, viscose, lyocell, and acetate. Using cellulose filaments formed from naturally sourced cellulose helps to provide bio-based or non-fossil nonwovens. Natural cellulose is preferably unmodified. Examples of unmodified natural cellulose are viscose or lyocell, with lyocell being preferred. Using unmodified cellulose filaments formed from natural cellulose further helps to provide plastic-free nonwovens. Typically, synthetic cellulose filaments can include a variety of filament types.

[0012] Synthetic cellulose filaments are preferably solution-blown filaments. WO 2018 / 184042 discloses a method for manufacturing a nonwoven material composed of substantially continuous cellulose filaments. The method includes preparing a cellulose-containing spinning solution, such as cellulose dissolved in N-methylmorpholine N-oxide (NMMO), extruding the spinning solution through a spinneret, drawing the extruded spinning solution using a high-speed airflow, forming a web on a moving surface, and washing and drying the web. During drawing and / or web forming, a coagulating liquid capable of causing the dissolved cellulose to coagulate is applied. This method is described as similar to or analogous to the “meltblown” method used for producing synthetic thermoplastic fibers. The disclosed method is referred to as “solution-blown” when the cellulose is dissolved in a solution (i.e., not molten thermoplastic) and the spinning and air temperatures are only moderately elevated.

[0013] Natural cellulose fibers can be pulp fibers, such as wood fibers. Wood fibers are particularly suitable. Both softwood and hardwood fibers are appropriate. Regenerated wood fibers can also be used. Fiber length will vary from about 3 mm for softwood fibers to about 1.2 mm for hardwood, and can be even shorter for regenerated fibers. Many other types of natural fibers can also be used, especially those with absorbent properties and a tendency to form coherent sheets. Other examples of natural cellulose fibers are seed hair fibers, such as cotton, kapok, or milkweed; leaf fibers, such as sisal, Manila hemp, pineapple, or New Zealand hemp; and bast fibers, such as flax, hemp, jute, or kenaf. Natural cellulose fibers can be derived from multiple natural sources.

[0014] Synthetic staple fibers can be formed from polyethylene, polypropylene, polyester, polyamide, polylactide, polyhydroxyalkanoate, or cellulose, preferably from polylactide, polyhydroxyalkanoate, or cellulose, and more preferably from cellulose. Using staple fibers formed from polylactide, polyhydroxyalkanoate, or cellulose helps to provide bio-based or non-fossil, as well as biodegradable and compostable nonwovens. Synthetic staple fibers can also be formed from bio-based polyethylene, bio-based polypropylene, bio-based polyester, or bio-based polyamide. Using staple fibers formed from bio-based polyethylene, bio-based polypropylene, bio-based polyester, or bio-based polyamide helps to provide bio-based or non-fossil nonwovens. Furthermore, synthetic staple fibers can be formed from naturally derived cellulose such as regenerated cellulose. Examples of regenerated cellulose are rayon, viscose, lyocell, and acetate. Using staple fibers formed from naturally derived cellulose helps to provide bio-based or non-fossil nonwovens. Preferably, the natural cellulose is unmodified. Examples of unmodified natural cellulose are viscose or lyocell, preferably lyocell. The use of short fibers formed from unmodified natural cellulose further contributes to the provision of plastic-free nonwovens. In general, synthetic short fibers can include a variety of fiber types.

[0015] If the synthetic cellulose filaments and synthetic staple fibers are formed from unmodified natural cellulose, more preferably from viscose or lyocell fibers, and most preferably from lyocell fibers, then plastic-free nonwovens can be provided. The cellulose filaments and staple fibers can be formed from the same unmodified natural cellulose or different unmodified natural celluloses, respectively.

[0016] Hydroentangled nonwovens can have a strength of 20 to 200 g / m². 2 Preferred concentration: 40 to 120 g / m 2 The base weight.

[0017] In a second aspect, the present invention relates to a wiping cloth comprising a hydroentangled nonwoven fabric as disclosed herein. The wiping cloth is a disposable cloth for cleaning objects. The wiping cloth may be provided as a discrete sheet or as a roll of wiping material from which a sheet of suitable length may be torn.

[0018] The wipes may be wet wipes, such as wipes that also contain liquid formulations. Liquid formulations may contain cleaning agents, disinfectants, and / or soothing agents.

[0019] In a third aspect, the present invention relates to a method of manufacturing a nonwoven fabric, wherein a web of man-made cellulose filaments is provided, and natural cellulose fibers and man-made short fibers are wet-formed onto the top of the web of man-made cellulose filaments to form a fiber web comprising the man-made cellulose filaments, natural cellulose fibers and man-made short fibers, and the fiber web is subsequently hydroentangled to form a nonwoven fabric, wherein the man-made short fibers have a length of 10 mm to 20 mm, preferably 10 mm to 15 mm.

[0020] Hydroentanglement, or jet spinning, is described in CA841 938. Hydroentanglement involves forming a fiber web, which is then entangled with filaments and fibers under high pressure via very fine water jets. Several water jets are directed onto the fiber web supported by a movable fabric.

[0021] Typically, a fiber dispersion comprising natural cellulose fibers and man-made short fibers can be wet-formed onto the top of the man-made cellulose filament web. Therefore, the wet-forming of the natural fibers and short fibers on the top of the web can be performed in a single operation.

[0022] Synthetic short fibers can be foam-formed onto the top of the synthetic cellulose filament web. Foam forming of the fibers helps to achieve uniform shaping. Short fibers with a length of 10 mm to 20 mm are difficult to distribute uniformly in other respects, especially when dispersed with natural fibers.

[0023] WO 96 / 02701 discloses hydroentanglement of fiber webs in foam forming. Foam forming is a special variant of wet web forming in which water, in addition to fibers and chemicals, contains a surfactant that enables the formation of foam, in which fibers can be embedded within and between foam bubbles. The fibers can be pulp fibers and other natural and synthetic fibers.

[0024] Webs of synthetic cellulose filaments can be provided by extruding a cellulose-containing solution through a spinneret onto a moving surface, for example, by solution blowing of a cellulose-containing solution. Alternatively, the webs of synthetic cellulose filaments can be provided as pre-formed webs, such as web material rolls. Preferably, the webs of the synthetic cellulose filaments have a width of 2 to 50 g / m. 2 Preferred concentration: 15 to 40 g / m 2 The base weight.

[0025] Additives such as wet strength agents, adhesive chemicals, latex, and desiccant can be added during the manufacturing of nonwovens.

[0026] The method for manufacturing nonwovens can also be characterized by the proposed method for the hydroentangled nonwovens disclosed herein.

[0027] In a fourth aspect, the present invention relates to a method for preparing a wiping material, the method comprising a method of manufacturing a nonwoven fabric as described herein, wherein the nonwoven fabric is further cut, perforated, folded, micro-creased, calendered, embossed, printed and / or provided with a liquid formulation.

[0028] The method for manufacturing a wiping material may also be characterized by its application to the wiping material disclosed herein. Attached Figure Description

[0029] Figure 1 An exemplary production line for manufacturing hydroentangled nonwovens according to the present invention is illustrated schematically. Detailed Implementation

[0030] refer to Figure 1An exemplary production line for manufacturing a hydroentangled nonwoven fabric according to the invention will be described. The production line is formed along an endless forming fabric 1, on which artificial cellulose filaments 2 are laid and excess air is drawn in. The resulting web 3 of artificial cellulose filaments is advanced to a wet web-forming stage 4, where a foam comprising wood pulp fibers 5 and short fibers 6 is wet-laid on top of the web 3, and excess water is drained through the forming fabric 1. The resulting web comprising the artificial cellulose filaments, wood pulp fibers, and short fibers is advanced to a hydroentanglement stage 7, where the filaments and fibers are combined by the action of numerous fine, high-pressure water jets impacting the web to form a nonwoven fabric 8, and hydroentanglement water is drained through the forming fabric 1.

[0031] The resulting nonwoven fabric 8 is then moved to a drying stage (not shown), where the nonwoven fabric 8 is dried, and further moved to a stage for rolling, cutting, packaging, etc. (not shown).

[0032] according to Figure 1 In the embodiment shown, the filaments 2 are laid directly on the shaped fabric 1, where they are allowed to form widths 3.

[0033] Air used to extract and stretch the filaments is drawn through the forming fabric 1 so that the filaments 2 follow the airflow into the web of the forming fabric to remain there.

[0034] When the filament 2 is laid on the shaped fabric 1, the speed of the filament 2 is much higher than that of the shaped fabric, so that the filaments will form irregular loops and bends as they are collected on the shaped fabric to form a very randomized width 3.

[0035] Wood pulp fibers 5 and short fibers 6 are pulped in a conventional manner, either mixed together or first pulped separately and then mixed, with the addition of conventional papermaking additives such as wet and / or dry strength agents, retention aids, and / or dispersants to produce a pulp in which the wood pulp fibers and short fibers are well mixed in water. This mixture is pumped through a wet-forming headbox 4 onto a moving forming fabric 1, where it is laid out on web 3. Excess water is drawn through the web 3 of the filaments 2 laid on the forming fabric 1 by a suction box arranged below the forming fabric and flows downwards through the forming fabric.

[0036] The web 3 of filaments 2, wood pulp fibers 5, and short fibers 6 is hydroentangled while still supported by the formed fabric 1. In the hydroentanglement stage 7, different filament and fiber types are hydroentangled to obtain a composite nonwoven fabric 8. The hydroentanglement stage 7 may include several transverse bars with multiple rows of nozzles from which very fine water jets are guided against the web 3 at very high pressure to provide hydroentanglement of the filaments and fibers. The water jet pressure can be adapted to provide a specific pressure distribution with different pressures in different rows of nozzles. Alternatively, or subsequently, the web 3 may be transferred to a separate hydroentangled fabric (not shown) where (further) hydroentanglement occurs.

[0037] The drying stage (not shown) can be carried out on conventional web drying equipment, preferably of the type used for drying tissue paper, such as air-penetration drying or Yankee drying. After drying, the material is typically wound into a master roll before conversion.

[0038] The material is then transformed into a suitable form and packaged in a known manner.

[0039] The present invention is not limited to the embodiments or examples shown in the accompanying drawings or described herein, but may be further modified within the scope of the claims.

[0040] Example

[0041] By using wood pulp ( Plus Fluff Pulp (from International Paper's Southern Cork Fluff) or a dispersion of wood pulp and lyocell short fibers (1.7 dtex) was foamed onto a web of solution-blown lyocell filaments to prepare a nonwoven fabric in a Formette sheet forming machine. Different lengths and contents of lyocell short fibers were applied to three different webs of solution-blown lyocell filaments, as shown in Tables 1, 2, and 3.

[0042] The nonwoven fabric was then hydroentangled on one side of the width using 10 manifolds / jet strips, of which 120 strips had entanglement nozzle orifices with a diameter of 120 μm and a spacing of 0.8 mm between the orifices.

[0043] For solution-blown Lyocell filaments and hydroentangled nonwovens, the basis weight (measured according to NWSP130.1.R0(15)) and thickness (measured according to NWSP 120.6R0(15)) as well as dry and wet tensile properties (measured according to NWSP 110.4R1(22), 50 mm wide strip, 50 mm clamping distance, constant elongation rate, test speed 100 mm / min, and for wet tensile properties, wetting to saturation) were obtained, as shown in Tables 1, 2 and 3.

[0044] The tensile index used in this specification is calculated according to the following formula:

[0045]

[0046] X2 - Tensile Index (Nm / g)

[0047] X 1MD -MD tensile strength (N / m)

[0048] X 1CD -CD tensile strength (N / m)

[0049] g1 - Basis weight (g / m³) 2 )

[0050] To facilitate the evaluation of the effects of short fiber length and content on the strength of nonwovens, the percentage increase in dry and wet tensile properties of nonwovens containing short fibers was calculated relative to the tensile properties of nonwovens without short fibers. The obtained data are shown in Tables 4 and 5.

[0051] Table 1. Preparation of the first solution spray width and hydroentangled nonwoven fabric

[0052]

[0053] Table 2 shows the preparation of the second solution spray width and hydroentangled nonwoven fabric.

[0054]

[0055] Table 3. Preparation of the third solution spray width and hydroentangled nonwoven fabric

[0056]

[0057] Table 4. Effect of short fiber length on nonwoven strength (percentage increase relative to samples without short fibers)

[0058]

[0059]

[0060] Table 5. Effect of short fiber content on nonwoven strength (percentage increase relative to samples without short fibers)

[0061]

Claims

1. A hydroentangled nonwoven fabric, comprising: Man-made cellulose filaments, Natural cellulose fibers, and Man-made short fibers, The artificial short fibers have a length of 10 mm to 20 mm, preferably 10 mm to 15 mm.

2. The hydroentangled nonwoven fabric according to claim 1, comprising: 10 to 50% by weight of man-made cellulose filaments, 20 to 85% by weight of natural cellulose fibers; and 2.5 to 25% by weight of man-made staple fibers, The weight percentage is based on the total weight of the nonwoven fabric.

3. The hydroentangled nonwoven fabric according to claim 2, comprising: 15 to 35% by weight of synthetic cellulose filaments, 40 to 75% by weight of natural cellulose fibers; and 5 to 20% by weight of man-made short fibers, The weight percentage is based on the total weight of the nonwoven fabric.

4. The spunlace nonwoven fabric according to any one of the preceding claims, wherein the artificial cellulose filament is formed from cellulose of natural origin, preferably from unmodified natural cellulose, more preferably from viscose fiber or lyocell, and most preferably from lyocell.

5. The hydroentangled nonwoven fabric according to any one of the preceding claims, wherein the artificial short fibers are formed of polyethylene, polypropylene, polyester, polyamide, polylactide, polyhydroxyalkanoate or cellulose, preferably polylactide, polyhydroxyalkanoate or cellulose, more preferably cellulose.

6. The hydroentangled nonwoven fabric according to claim 5, wherein the artificial short fibers are formed from naturally derived cellulose, preferably from unmodified natural cellulose, more preferably from viscose or lyocell, and most preferably from lyocell.

7. The spunlace nonwoven fabric according to any one of claims 4 to 6, wherein the artificial cellulose filaments and the artificial staple fibers are formed from unmodified natural cellulose, more preferably from viscose or lyocell, and most preferably from lyocell.

8. A wiping material comprising a hydroentangled nonwoven fabric according to any one of claims 1 to 7.

9. The wiping material according to claim 8, wherein the wiping material is a wet wiping material, such as a wiping material further comprising a liquid preparation.

10. A method for manufacturing a nonwoven fabric, wherein Provides the width of synthetic cellulose filaments, and Natural cellulose fibers and man-made short fibers are wet-formed on top of the web of the man-made cellulose filament. Therefore, a fiber web is formed comprising the aforementioned synthetic cellulose filaments, natural cellulose fibers, and synthetic staple fibers, and The fiber webs are then hydroentangled to form a nonwoven fabric. The artificial short fibers have a length of 10 mm to 20 mm, preferably 10 mm to 15 mm.

11. The method of claim 10, wherein the fiber dispersion of the natural cellulose fiber and the artificial short fiber is wet-formed on top of the web of the artificial cellulose filament.

12. The method of claim 10 or 11, wherein the synthetic short fibers are foam-formed on top of the web of the synthetic cellulose filaments.

13. The method according to any one of claims 10 to 12, wherein the width of the artificial cellulose filament is provided by extruding a cellulose-containing solution onto a moving surface through a spinneret, such as by blowing a solution containing a cellulose solution.

14. The method according to any one of claims 10 to 13, characterized in that... The method according to any one of claims 2 to 7.

15. A method of manufacturing a wiping material, comprising the method according to any one of claims 10 to 14, wherein the nonwoven material is further cut, perforated, micro-creased, calendered, embossed, printed, and / or provided with a liquid formulation.

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