Production process of fluffy hydroentangled nonwoven fabric and fluffy hydroentangled nonwoven fabric

Abstract

The application discloses a production process of fluffy hydroentangled non-woven fabric, comprising the following steps: S1, spreading the web output by a carding machine on a screen to obtain a laminated web of straight layers and cross layers; S2, guiding the laminated web to a jacquard roller, and clamping the straight layers between the cross layers and the jacquard roller; S3, drying the laminated web on the surface of the jacquard roller in the direction from the cross layers to the straight layers to obtain the fluffy hydroentangled non-woven fabric. The production process of the fluffy hydroentangled non-woven fabric clamps the straight layers between the cross layers and the jacquard roller for hydroentanglement, and the inner layer web of the cross layers and the straight layers is punctured to the outer layer web under the action of hydroentanglement; compared with the cross layers, the fiber orientation consistency of the straight layers is higher, and the straight layers are subjected to hot pressing, so that the jacquard surface is less prone to fuzzing and pilling; the fiber cohesion of the straight layers is low and easy to slip, so that the jacquard pattern tends to be three-dimensional. The application further discloses a fluffy hydroentangled non-woven fabric.

Description

Technical Field

[0001] This invention relates to the field of nonwoven fabric production technology, specifically to a production process for fluffy spunlace nonwoven fabric and fluffy spunlace nonwoven fabric. Background Technology

[0002] High-pressure micro-jet water is sprayed onto one or more layers of fiber web, causing the fibers to entangle and thus strengthening the web to a certain strength. The resulting fabric is called spunlace nonwoven fabric. Compared to hot-air cotton, spunlace nonwoven fabric does not have a melt-bonded structure between fibers, better preserving the fiber structure. It has better softness, breathability, and water absorption, and is therefore widely used in sanitary napkins, wet wipes, medical supplies, and clothing linings.

[0003] Nonwoven fabrics mainly employ two web laying methods: straight-lay web and cross-lay web. Nonwoven fabrics made from cross-lay webs through hydroentangling have high strength and dimensional stability. However, using cross-lay webs as jacquard surfaces presents the following technical problems: the fibers in the cross-layers are well-coordinated and do not easily slip, resulting in jacquard patterns that are not three-dimensional enough and lack sufficient bulk. Summary of the Invention

[0004] One of the objectives of this invention is to overcome the defects in the prior art and provide a production process for fluffy spunlace nonwoven fabric. During jacquard processing, the straight-lay layer is sandwiched between the cross layer and the jacquard roller, resulting in a full and fluffy nonwoven fabric with a more three-dimensional pattern.

[0005] To achieve the above-mentioned technical effects, the technical solution of the present invention is as follows: a production process for fluffy spunlace nonwoven fabric, comprising the following steps:

[0006] S1. Lay the fiber web output from the carding machine onto the wire mesh curtain to obtain a stacked fiber web of straight and cross layers;

[0007] S2. Guide the laminated fiber web to the jacquard roller, wherein the straight layer is sandwiched between the cross layer and the jacquard roller;

[0008] S3. The stacked fiber web on the surface of the jacquard roller is hydroentangled along the direction from the cross layer to the straight layer, and then dried to obtain the fluffy hydroentangled nonwoven fabric.

[0009] The surface of the jacquard roller is provided with unit protrusions and unit recessed dewatering sections. By using negative pressure to attract the water flow that has been spun into the fiber web, the water flow is drawn away from the fiber web from the unit recessed dewatering section. The water flow guides the fibers in the fiber web to slide into the unit recessed dewatering section, forming the protrusions on the jacquard surface.

[0010] The preferred technical solution is that S1 includes:

[0011] S10. Press and heat the outer layer of the straight-laid layer to obtain a pressed and heat-treated fiber web;

[0012] S11: Overfeeding the heat-pressed fiber mesh to form a pleated outer layer of straight-laid fiber mesh;

[0013] S12. The outer layer of direct-laid fiber web is stacked with the inner layer of direct-laid fiber web and the cross layer to obtain a stacked fiber web;

[0014] The flattened length of the outer layer of straight-laid fiber web along the fiber web extension direction is greater than the length of the stacked fiber web.

[0015] The pleated structure is based on the concave-convex structure of the fiber web. Compared with the pleated fiber web formed by vibratory vertical web laying during web laying, the pleated structure formed by pressing and positive overfeeding is more uniform, adapting to the evenly distributed depressions and protrusions on the jacquard roller surface, ultimately forming a nonwoven fabric with a more uniform fluffiness. The concave-convex structure formed by pre-pressing and the pleated structure formed by positive overfeeding both help to improve the cohesion of the straight-laid fiber web. During the hydroentangling process, the pleated structure comes into contact with the jacquard roller surface. The flattened length of the outer straight-laid fiber web is greater than the circumference of the dewatering depression on the jacquard roller surface. The fibers in the inner fiber web of the cross layer and the straight-laid layer are punctured by hydroentangling. Under the restriction of the dewatering depression, the pleated structure of the outer straight-laid fiber web is slightly unfolded, and the punctured fibers fix the unfolded pleated structure. The pleated structure is further unfolded during subsequent processing and use, making the jacquard protrusions of the nonwoven fabric more abundant and fluffy.

[0016] A preferred technical solution is that the concave-convex structure is fully distributed on the outer fiber web, and one of the arrangement directions of the concave-convex structure is consistent with the arrangement direction of the pleated structure.

[0017] Optionally, the pleats of the outer fiber web can be strips extending along the width direction of the fiber web, strips with acute angles between the fiber web width direction and the extension direction, or dots evenly distributed along the width and length directions of the fiber web. Pressing can be performed using rollers or pressing equipment with the upper and lower parts facing each other.

[0018] The preferred technical solution is that the convex and concave units of the shaped concave and convex structure are evenly distributed along the fiber web extension direction and the width direction;

[0019] The jacquard roller has a unit protrusion and a unit recessed dewatering part on its roller surface. The orthogonal projection size of the unit protrusion in the cross layer of the laminated fiber web along the width direction is L1, and the size of the unit recessed dewatering part along the roller axis is L2, where L1 is less than L2.

[0020] In addition to the pleated structure in the extension direction of the fiber web, the concave-convex structure in the width direction of the stacked fiber web is introduced into the unit recessed dehydration section, so that the flat size of the outer fiber web placed in the unit recessed dehydration section is larger than the size of the unit recessed dehydration section, which is conducive to the deformation, unfolding and fixing of the outer fiber web in the width direction, and further improves the fluffy effect.

[0021] A preferred technical solution is that the raw material fibers of the outer fiber web are composed of polyester fibers and hydrophilic fibers, the mass percentage of polyester fibers in the outer fiber web is 45% to 75%, the raw material fibers of the cross layer are mainly composed of hydrophilic fibers, and the mass percentage of polyester fibers in the outer fiber web can be specifically selected from point values ​​of 45%, 47%, 50%, 53%, 55%, 57%, 59%, 60%, 62%, 64%, 67%, 70%, and 75%, as well as the range of two point values ​​as the maximum and minimum values.

[0022] The role of polyester fibers in the outer web is to fix the shape of the heat press, facilitate the formation of pleats, and thus stabilize the pleat shape during positive overfeeding and hydroentangling production. Furthermore, the raw materials in the outer web also include hydrophilic fibers, the selection of which includes, but is not limited to, viscose or cotton fibers. Reducing the polyester fiber content in the outer web facilitates the slippage of fibers in the jacquard raised sections and enhances the three-dimensional effect of the jacquard during subsequent hydroentangling production and use, while reducing the deformation limitations imposed by the setting polyester on the raised sections.

[0023] A preferred technical solution is that the raw material fibers of the outer layer web further include cotton fibers or viscose fibers, the pressing temperature is 160-175℃, and the pressing pressure is 0.5-1.3 kg / cm². 2 The outer fiber web has a basis weight of 33–56 g / m². 2 The pressing and feeding speed is 60-90m / min.

[0024] Based on the preferred range, if the basis weight of the outer layer is too large, the fiber density of the outer layer obtained by heat pressing will be high, the cohesion between fibers will be too strong, and the fiber slippage and deformation of the outer layer will be limited; if the basis weight of the outer layer is too small, the outer layer will be more prone to bulging and deformation, but the cohesion and entanglement of the jacquard surface fibers obtained by single-sided hydroentangling will be insufficient, and the bulging and deformed outer layer will be prone to collapse and napping.

[0025] Furthermore, when the outer layer of the fiber web is a blend of polyester and cotton fibers, the pressing temperature is 165–175°C; when the outer layer of the fiber web contains viscose fibers, the pressing temperature is 160–167°C. The pressing pressure and pressing feed speed are adjusted accordingly to avoid problems such as viscose loosening and fiber strength damage.

[0026] A preferred technical solution is that S3 includes at least one humidification and dehydration process: humidifying the hydroentangling layered fiber web on the surface of the jacquard roller; and the jacquard roller continuously dehydrating the layered fiber web. The humidification and dehydration process guides water flow towards the recessed dehydration section of the unit, causing more fibers to gather, slide, and deform towards the protrusions on the jacquard surface and entangle with the punctured fibers, thereby effectively supporting the bulging and deformation of the outer layer of fiber web at the jacquard protrusions.

[0027] A preferred technical solution is that S3 further includes: while the jacquard roller is continuously dewatering, an ultrasonic roller presses against the surface of the laminated fiber web away from the jacquard roller to perform ultrasonic treatment on the laminated fiber web, so as to fluff up at least the cross-layer fibers corresponding to the unit recessed dewatering part of the jacquard roller.

[0028] Tiny air bubbles in the water within the fiber web undergo cavitation under the action of the ultrasonic roller. The bursting of these bubbles impacts and vibrates the fibers of the cross-layer and inner fiber web, making the fibers in the nonwoven fabric more fluffy. Compared to the raised section of the jacquard roller, the recessed dewatering section of the unit has a larger fiber sliding space in the thickness direction of the fiber web, further optimizing the deformation support effect of the sliding fibers on the outer fiber web at the jacquard raised section.

[0029] A preferred technical solution is that the ultrasonic frequency of the ultrasonic treatment is 30kHz to 40kHz, and the moisture content of the ultrasonically treated laminated fiber web is not less than 60%. If the moisture content is too low, the ultrasonic waves will act more on the nonwoven fibers, and the cavitation effect will have less impact on the fiber deformation of the cross-layer and inner layer fiber web.

[0030] The second objective of this invention is to provide a fluffy spunlace nonwoven fabric, which is produced by the above-mentioned fluffy spunlace nonwoven fabric production process.

[0031] The advantages and beneficial effects of this invention are as follows:

[0032] The production process of this fluffy spunlace nonwoven fabric involves sandwiching the straight layer between the cross layer and the jacquard roller for hydroentangling. The inner fiber web of the cross layer and the straight layer pierces into the outer fiber web under the action of hydroentangling.

[0033] Compared to cross-layered fabrics, straight-laid fabrics have a higher fiber orientation consistency and are hot-pressed, making the jacquard surface less prone to pilling and fuzzing.

[0034] The fibers in the direct-lay layer have low cohesion and are prone to slippage, thus making the jacquard pattern more three-dimensional;

[0035] Based on the use of a straight-laid layer as the jacquard surface, the outer layer of the straight-laid layer is pre-heat-pressed, and the fibers in the fiber web are fixed by the pre-pressed concave-convex structure. The positive overfeed is then used to form a regular and evenly distributed pleated structure. The pleated structure is then hydroentangled by the jacquard roller, and the protrusions of the jacquard surface are further enlarged, resulting in a more three-dimensional, fluffy and soft nonwoven fabric. Detailed Implementation

[0036] The specific embodiments of the present invention will be further described below with reference to examples. These examples are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0037] The fiber colors of the straight-lay layer and the cross-lay layer can be the same or different. Preferably, the degree of hydrophilicity of the jacquard surface and the spunlace surface can also be distinguished by color.

[0038] Understandably, the hydroentangled fiber web is dehydrated, dried, slit, and packaged into rolls to obtain the finished fabric rolls.

[0039] The hydrophilic fibers in nonwoven fabrics include, but are not limited to, cotton fibers and viscose fibers. In addition to hydrophilic fibers, polyester fibers are also added to nonwoven fabrics to enhance their strength, abrasion resistance, quick-drying properties, wrinkle resistance, and other properties.

[0040] The spunlace nonwoven fabric is made by stacking several fiber webs. A single layer of fiber web uses the same fiber or a blend of two or more fibers.

[0041] raw material fiber

[0042] Viscose fiber: 1.6-1.7 dtex;

[0043] Polyester fiber: 1.5-1.6 dtex.

[0044] Example 1

[0045] Example 1: The production process of fluffy spunlace nonwoven fabric is as follows:

[0046] S10, viscose fiber and polyester fiber are processed sequentially through opening, blending and carding at a mass ratio of 35:65 to obtain 45±1g / m². 2 The outer fiber mesh is laid directly and then introduced into the ironing equipment. The ironing temperature is 160-165℃, and the ironing pressure is 0.9 kg / cm². 2 The pressing and feeding speed is 70m / min, and the raised roller surface of the pressing roller has raised dots evenly distributed along the width and extension direction of the fiber web.

[0047] S11: The heat-pressed fiber mesh is fed onto the mesh curtain at a positive overfeed rate of 50% to form a pleated structure, resulting in an outer layer of straight-laid fiber mesh.

[0048] S12: The inner layer of the direct-lay layer is made of fiber mesh (30g / m²). 2 ) and cross-laminated fiber web (100g / m 2 The layers are stacked on top of the outer straight-laid fiber web to obtain a multilayer fiber web. The inner fiber web and the cross-layer fiber web are both composed of 20% polyester fiber and 80% viscose fiber.

[0049] S2. Guide the laminated fiber web to the pearl pattern jacquard roller, with the straight layer sandwiched between the cross layer and the jacquard roller; the feed speed of the jacquard roller is 60m / min, and the tension of the laminated fiber web is 95N;

[0050] The raised and recessed units of the shaped raised and recessed structure are evenly distributed along the fiber web extension direction and the width direction; the roller surface of the jacquard roller has a raised unit and a recessed dewatering unit. The orthogonal projection size of the raised and recessed units in the cross layer of the fiber web stacked along the width direction is L1, and the size of the recessed dewatering unit along the roller axis is L2, where L1 is smaller than L2.

[0051] S3. The layered fiber web on the surface of the spunlace jacquard roller along the direction from the cross layer to the straight layer is dried at a pressure of 80 bar and a temperature of 135°C to obtain a fluffy spunlace nonwoven fabric.

[0052] Example 2

[0053] Example 2 is based on Example 1, except that a row of atomizing nozzles arranged along the axial direction of the roller is provided on the discharge side of the hydroentangling assembly and on the radially outer side of the jacquard roller.

[0054] S3: The layered fiber web on the surface of the spunlace jacquard roller along the direction from the cross layer to the straight layer is spun at a pressure of 80 bar. The spunlace fiber web is kept in contact with the surface of the jacquard roller. The spunlace fiber web is humidified by an atomizing nozzle. The unit recessed dewatering section of the jacquard roller continuously dewaters the spunlace fiber web on its roller surface under vacuum. Then the nonwoven fabric is separated from the jacquard roller and introduced into a 135°C drying tunnel to dry, resulting in a fluffy spunlace nonwoven fabric.

[0055] Example 3

[0056] Example 3 is based on Example 2, except that an ultrasonic roller is provided on the discharge side of the atomizing nozzle and on the radial outer side of the jacquard roller.

[0057] S3 of Example 3 further includes: while the jacquard roller is continuously dewatering, the ultrasonic roller presses against the non-jacquard surface (the nonwoven fabric surface opposite to the jacquard surface) of the laminated fiber web to perform ultrasonic treatment on the laminated fiber web. The ultrasonic frequency of the ultrasonic treatment is 32kHz, and the moisture content of the laminated fiber web treated by the ultrasonic treatment is calculated to be 73% based on the vacuum dewatering speed.

[0058] Example 4

[0059] Example 4 is based on Example 3, except that: S10, viscose fiber and polyester fiber are processed sequentially in a mass ratio of 20:80 through opening, blending and carding to obtain 45±1g / m 2 The outer fiber mesh is laid straight.

[0060] Example 5

[0061] Example 5 is based on Example 3, except that: viscose fiber and polyester fiber are processed sequentially in a mass ratio of 35:65 through opening, blending, and carding to obtain 60±1g / m 2 The outer fiber mesh is laid straight.

[0062] Example 6

[0063] Example 6 is based on Example 1, except that: the outer fiber web is laid directly with a density of 67.50 g / m². 2 Inner layer fiber mesh 30g / m 2 and cross-laminated fiber web 100g / m 2 A comparative layered fiber web is configured, and a semi-cross-woven spunlace jacquard nonwoven fabric is produced using the same process as in Example 1, wherein the straight-laid layered fiber web abuts against the roller surface of the jacquard roller to form a jacquard surface.

[0064] Comparative Example

[0065] According to the direct-lay outer fiber mesh 67.50g / m 2 Inner layer fiber mesh 30g / m 2 and cross-laminated fiber web 100g / m 2 A comparative layered fiber web is configured, and a semi-cross-woven hydroentangled jacquard nonwoven fabric is produced using the same process as in Example 1, wherein the cross-layered fiber web abuts against the roller surface of the jacquard roller to form a jacquard surface.

[0066] Testing of Example and Comparative Samples:

[0067] Testing standard: GB / T 24442.1 Textiles. Determination of compression properties. Part 1: Constant method. Mean values ​​of compression ratio and recovery rate under light compression of 0.5 kPa for 10 s and heavy compression of 30 kPa for 60 s.

[0068] The calculated compression and recovery rates for the examples and comparative examples are shown in the table below:

[0069]

[0070] In the initial products obtained by drying in the drying tunnel, the thicknesses of Examples 1-6 were similar, while the thickness of Comparative Example 1 was slightly smaller; the recovery rates of the samples of Example 6 and the Comparative Example were similar, but the pressing rates differed significantly, indicating that the fiber orientation of the cross-layer and the cohesion between fibers limited the increase in jacquard protrusions and three-dimensionality.

[0071] As shown in the table above, heat pressing and positive overfeeding have a significant effect on improving the product compression rate. Both atomized nozzle humidification and dehydration, and humidifying ultrasonic roller treatment methods are beneficial to increasing the probability of deformation of the inner layer fiber web and cross-linked fibers towards the jacquard surface in the straight-lay layer, especially the fiber deformation of the inner layer fiber web, which is conducive to further improving the product thickness and fluffiness. If the polyester content in the outer layer fiber web of heat pressing is too high or the fiber web weight is too large, it is not conducive to the sample maintaining a high recovery rate.

[0072] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A production process for fluffy spunlace nonwoven fabric, characterized in that, Includes the following steps: S1. Lay the fiber web output from the carding machine onto the wire mesh curtain to obtain a stacked fiber web of straight and cross layers; S2. Guide the laminated fiber web to the jacquard roller, wherein the straight layer is sandwiched between the cross layer and the jacquard roller; S3. The stacked fiber web on the surface of the jacquard roller is hydroentangled along the direction from the cross layer to the straight layer, and then dried to obtain the fluffy hydroentangled nonwoven fabric; S1 includes: S10. Press and heat the outer layer of the straight-laid layer to obtain a pressed and heat-treated fiber web; S11: Overfeeding the heat-pressed fiber mesh to form a pleated outer layer of straight-laid fiber mesh; S12. The outer layer of direct-laid fiber web is stacked with the inner layer of direct-laid fiber web and the cross layer to obtain a stacked fiber web; The flattened length of the outer layer of straight-laid fiber web along the fiber web extension direction is greater than the length of the stacked fiber web; The pre-pressed textured structure is fully distributed on the outer fiber mesh, and one of the arrangement directions of the textured structure is consistent with the arrangement direction of the pleated structure.

2. The production process of the fluffy spunlace nonwoven fabric according to claim 1, characterized in that, The concave-convex units of the concave-convex structure are evenly distributed along the fiber web extension direction and the width direction. The jacquard roller has a unit protrusion and a unit recessed dewatering part on its roller surface. The orthogonal projection size of the unit protrusion in the cross layer of the laminated fiber web along the width direction is L1, and the size of the unit recessed dewatering part along the roller axis is L2, where L1 is less than L2.

3. The production process of the fluffy spunlace nonwoven fabric according to claim 1, characterized in that, The outer layer of the fiber web is composed of polyester fibers and hydrophilic fibers. The mass percentage of polyester fibers in the outer layer of the fiber web is 45% to 75%, and the raw material fibers of the cross-layer are mainly composed of hydrophilic fibers.

4. The production process of the fluffy spunlace nonwoven fabric according to claim 1, characterized in that, The outer layer of the fiber web also includes cotton or viscose fibers as raw materials. The pressing temperature is 160–175℃, and the pressing pressure is 0.5–1.3 kg / cm². 2 The outer fiber web has a basis weight of 33–56 g / m². 2 The pressing and feeding speed is 60-90m / min.

5. The production process of the fluffy spunlace nonwoven fabric according to claim 1, characterized in that, S3 includes at least one humidification and dehydration process: humidifying the hydroentangled fiber web on the surface of the jacquard roller; and continuously dehydrating the fiber web by the jacquard roller.

6. The production process of the fluffy spunlace nonwoven fabric according to claim 5, characterized in that, S3 further includes: while the jacquard roller is continuously dewatering, an ultrasonic roller presses against the surface of the laminated fiber web away from the jacquard roller to perform ultrasonic treatment on the laminated fiber web, so as to fluff up at least the cross-layer fibers corresponding to the unit recessed dewatering portion of the jacquard roller.

7. The production process of the fluffy spunlace nonwoven fabric according to claim 6, characterized in that, The ultrasonic frequency of the ultrasonic treatment is 30kHz to 40kHz, and the moisture content of the ultrasonically treated laminated fiber web is not less than 60%.

8. A fluffy spunlace nonwoven fabric, characterized in that, It is produced by the production process of fluffy spunlace nonwoven fabric as described in any one of claims 1 to 7.

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