A preparation process for modified nonwoven fabrics that are easy to inkjet print

Abstract

This invention relates to the field of nonwoven fabric technology and discloses a preparation process for modified nonwoven fabric that is easy to inkjet print, comprising the following steps: S1, preparing nonwoven fabric: preparing fibers according to the following weight parts: 4-7 parts wood pulp fiber, 5-12 parts resin fiber, 3-5 parts bamboo charcoal fiber, and 2-3 parts viscose fiber; mixing, opening, combing, hydroentangling, or needle punching the above fibers to form nonwoven fabric; S2, modifying nonwoven fabric; S3, preparing base color coating: rolling a base color slurry onto the upper surface of the modified nonwoven fabric and smoothing it; after the base color slurry dries, it forms a base color coating that is easy to inkjet print; the base color slurry comprises the following weight parts: 5-12 parts nano titanium dioxide, 20-28 parts adhesive, 0.6-1.35 parts coupling agent, and 0.3-0.5 parts dispersant. This invention has the beneficial effects of being environmentally friendly, being able to replace engineered wood veneer in composite use with boards, and improving the environmental protection level of boards.

Description

Technical Field

[0001] This invention relates to the field of nonwoven fabric technology, and in particular to a preparation process for modified nonwoven fabrics that are easy to inkjet print. Background Technology

[0002] In the home furnishing industry, the use of wood panels (mainly wood boards) is very large. The most common type is the melamine-faced board, which is usually made by hot-pressing a layer of engineered wood veneer onto the surface of the board, and then covering the engineered wood veneer with a layer of decorative paper. Engineered wood veneer is made by bonding solid wood veneers with an impregnating adhesive, which has a high formaldehyde content. The decorative paper, also called impregnated paper, is hot-pressed together with the engineered wood veneer. Because both the engineered wood veneer and the decorative paper have a high impregnating adhesive content, the melamine-faced board has a high formaldehyde content and is not environmentally friendly.

[0003] For example, Chinese patent number 2021110423445 discloses a preparation process for a nonwoven fabric that can replace natural wood veneer. This nonwoven fabric increases the bonding strength with decorative paper and better prevents glue penetration. However, when this nonwoven fabric is bonded to decorative paper with water-based environmentally friendly adhesive, the strength is insufficient. If impregnation adhesive is used, the impregnation adhesive contains a large amount of formaldehyde, resulting in insufficient environmental performance. Moreover, the nonwoven fabric still has defects in opacity and wrinkle resistance. When it is laminated with board after replacing engineered wood veneer, the surface decoration effect of the board cannot achieve the effect of existing melamine-faced boards. Furthermore, the nonwoven fabric lacks hardness and is prone to local indentation under pressure, thus affecting the surface decoration effect of the board. Summary of the Invention

[0004] To address the aforementioned problems in existing technologies where nonwoven fabrics are used in board surface coating devices, this invention provides a process for preparing modified nonwoven fabrics that facilitates inkjet printing. The modified nonwoven fabric produced by this process can directly replace natural wood veneer for board surface decoration. Its hardness, wrinkle resistance, and opacity all meet the requirements for board surface decoration. Furthermore, inkjet printing can be directly performed on the surface of the modified nonwoven fabric, eliminating the need for decorative paper and impregnation adhesive, resulting in better environmental performance.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A process for preparing modified nonwoven fabrics that are easy to inkjet print includes the following steps: S1. Preparation of nonwoven fabric: Prepare the fibers according to the following weight parts: 4-7 parts wood pulp fiber, 5-12 parts resin fiber, 3-5 parts bamboo charcoal fiber, and 2-3 parts viscose fiber. Mix the above fibers, open them, comb them, spun them into a web, or needle punch them to make nonwoven fabric. S2. Nonwoven fabric modification treatment: The nonwoven fabric is immersed in the modified slurry, so that the modified slurry fills the gaps in the nonwoven fabric. After that, it is processed by double roller extrusion and then dried in the drying zone to produce modified nonwoven fabric. The modified slurry includes the following components by weight: 5-10 parts of calcium carbonate powder, 20-32 parts of adhesive, 0.5-2.4 parts of coupling agent, and 0.5-1.5 parts of dispersant. S3. Preparation of base color coating: The base color slurry is roller-coated onto the upper surface of the modified nonwoven fabric and smoothed. After the base color slurry dries, a base color coating that is easy to inkjet print is formed. The base color slurry includes the following weight groups: 5-12 parts of nano titanium dioxide, 20-28 parts of adhesive, 0.6-1.35 parts of coupling agent, and 0.3-0.5 parts of dispersant.

[0006] By adopting the above technical solution: First, resin fibers and bamboo charcoal fibers are added to the fibers of the nonwoven fabric. Resin fibers have high strength, corrosion resistance, and wear resistance, increasing the overall strength and wear resistance of the nonwoven fabric. Bamboo charcoal fibers have good adsorption properties, and when combined with the board, they can absorb toxic gases such as formaldehyde emitted from the board, improving the environmental protection level of the board. After modifying the nonwoven fabric with a modified slurry, the pores in the nonwoven fabric are filled with the modified slurry, improving the hardness, strength, and light-blocking properties of the nonwoven fabric, while reducing its extensibility (preventing tensile cracking), breathability, and water absorption (preventing glue penetration during subsequent use). A layer is then applied to the surface of the modified nonwoven fabric... The base coating, containing nano-titanium dioxide, makes the surface of the modified nonwoven fabric smoother, whiter, and more even. This results in clearer patterns and more accurate colors during subsequent inkjet printing (of patterns or textures), while also improving the adhesion between the ink and the base coating. This modified nonwoven fabric can be directly bonded to the board using water-based environmentally friendly adhesive, thus directly replacing the hot-pressing (impregnation) lamination of engineered wood veneer and the board. Subsequently, inkjet printing directly replaces the hot-pressing impregnation of decorative paper (containing formaldehyde), significantly improving the environmental protection level of the board. Moreover, the modified nonwoven fabric can be rolled up and bent, making production and transportation more convenient. When laminating with the board, it can be directly wrapped at right angles.

[0007] Preferably, the fibers in step S1 also include 2-4 parts by weight of polyester fibers. The polyester fibers further improve the tensile and wrinkle resistance of the nonwoven fabric.

[0008] Preferably, the lower surface of the nonwoven fabric obtained in step S1 is subjected to meltblown treatment, and a meltblown layer is formed on the lower surface of the nonwoven fabric after meltblown treatment. During meltblown treatment, the polymer melt in the meltblown die includes the following components by weight: 5-8 parts of polypropylene fiber and 2-3 parts of ES adhesive fiber. The melt flow index of the polymer melt is 90-120 g / 10 min, the temperature of the meltblown die is 195-205℃, the air jet angle in the meltblown die is 35-40°, the pressure of the hot air in the meltblown die is 0.1-0.18 MPa, and the polymer melt extrusion rate is 0.2-0.4 g / hole / min.

[0009] A meltblown layer is formed on the lower surface of the nonwoven fabric. The fibers in the meltblown layer are denser and the pores are smaller, resulting in a difference in porosity between the nonwoven fabric and the meltblown layer. After subsequent impregnation with modified slurry, the nonwoven fabric contains more modified slurry, while the meltblown layer contains less. Therefore, the nonwoven fabric layer has higher hardness, is smoother, and has lower water absorption. When preparing the base color coating on the upper surface of the nonwoven fabric, it is smoother, reduces ink penetration, and makes the pattern clearer. On the other hand, the meltblown layer layer has relatively lower hardness, relatively higher water absorption, and better toughness. In use, the lower surface of the meltblown layer is bonded to the board with water-based environmentally friendly adhesive. The adhesive can better penetrate the meltblown layer but cannot penetrate the nonwoven fabric layer. This improves the bonding strength between the meltblown layer and the board while effectively preventing adhesive penetration into the nonwoven fabric. Moreover, the meltblown layer made of polypropylene fiber has better sound insulation, which can improve the sound insulation of the board after bonding with it.

[0010] Preferably, the nonwoven fabric obtained in step S1 has a basis weight of 60-150 g / m², the meltblown layer has a basis weight of 30-50 g / m², and the total basis weight of the nonwoven fabric after meltblowing treatment is 90-200 g / m². Hot rolling is then performed after meltblowing treatment. Hot rolling makes the bond between the meltblown layer and the nonwoven fabric more stable, and also makes the fiber gaps within the nonwoven fabric and meltblown layer smaller and more compact, allowing the overall fabric to maintain its bending toughness during subsequent modification treatments.

[0011] Preferably, the modified slurry in step S2 also contains 5-20 parts by weight of bamboo pulp fiber. The bamboo pulp fiber enhances the crack resistance and prevents the surface of the modified nonwoven fabric from cracking when rolled up or bent.

[0012] Preferably, the double rollers in step S2 are configured as two sets, namely a first double roller and a second double roller, with a pre-drying zone between the first double roller and the second double roller. The nonwoven base layer impregnated with the modified slurry passes through the first double roller, the pre-drying zone, the second double roller, and the drying zone in sequence. After passing through the pre-drying zone, the modified slurry in the nonwoven fabric reaches the basic hardening stage, and then enters the second double roller, finally reaching the fully hardened stage in the drying zone.

[0013] The process involves one extrusion, pre-drying, secondary extrusion, and drying to eliminate internal stress in the modified slurry during the hardening process and prevent cracking of the modified nonwoven fabric. At the same time, secondary rolling is performed during the basic hardening stage to make the surface of the nonwoven fabric smoother, which is conducive to the preparation of a smoother base color coating.

[0014] Preferably, the basis weight increase of the modified nonwoven fabric in step S2 is 25-45 g / m². That is, the content of the modified slurry is adjusted by the gap between the two rollers, and the basis weight increase of the nonwoven fabric is the basis weight after the modified slurry is cured. By limiting this basis weight, the surface of the modified nonwoven fabric will not crack when it is wound and bent, while ensuring that the hardness and wrinkle resistance of the modified nonwoven fabric meet the requirements.

[0015] Preferably, the second double roller has an array of spherical protrusions on its roller surface corresponding to the lower side of the nonwoven fabric. After passing through the second double roller, the lower surface of the nonwoven fabric forms an array of spherical recesses. These spherical recesses reduce the strength of the lower surface of the modified nonwoven fabric, facilitating bending and folding. Furthermore, when the lower surface of the modified nonwoven fabric is bonded to the board with adhesive, the spherical recesses increase the bonding surface and improve the adhesion strength. Thirdly, the bonding of the modified nonwoven fabric to the board increases the sound insulation performance of the board. Because the adhesive in the spherical recesses has a different composition than the modified nonwoven fabric, when sound waves are incident from one medium (the modified nonwoven fabric) to another medium with different acoustic properties (the solidified adhesive), reflection occurs at the interface between the two media (the spherical cavity wall of the spherical recess). The sound reflects along the spherical surface in different directions, greatly reducing sound penetration and improving sound insulation.

[0016] Preferably, the ratio of the depth of the spherical concave hole to the total thickness of the nonwoven fabric after modification in step S2 is 0.25-0.35.

[0017] Preferably, in step S3, the base color slurry comprises the following components by weight: 2-5 parts precipitated barium sulfate powder and 0.15-0.35 parts defoamer; the particle size of the nano titanium dioxide is 10-50 nm, and the particle size of the precipitated barium sulfate powder is 200-400 nm. The defoamer eliminates air bubbles in the slurry during stirring, resulting in a smoother base color coating. The precipitated barium sulfate powder is white; by utilizing the particle size difference between the precipitated barium sulfate powder and the nano titanium dioxide, the surface roughness of the final base color coating is greater than that obtained using only nano titanium dioxide. This roughness increases the surface area for inkjet printing, improves the adhesion between the ink and the base color coating, and makes the inkjet printed pattern clearer and with better color.

[0018] Therefore, the present invention has the following beneficial effects: (1) The modified nonwoven fabric does not contain formaldehyde, making it more environmentally friendly when used as a substitute for engineered wood veneer; (2) The base color coating of the modified nonwoven fabric can be directly inkjet printed to form a decorative layer, eliminating the need for decorative paper and the impregnation glue of the decorative paper, further improving the ring performance; (3) The overall quality of the modified nonwoven fabric is controllable and has better consistency; (4) The modified nonwoven fabric can be rolled up and folded, making transportation more convenient and the size design more flexible; (5) The modified nonwoven fabric can be rolled up and folded, so it can be continuously and automatically produced on the production line, greatly reducing manufacturing costs. Detailed Implementation

[0019] To make the technical problems to be solved, the technical solutions, and the beneficial technical effects of this invention clearer, the invention will be further described in detail below with reference to several exemplary embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of protection of this invention.

[0020] It should be understood that the terms "first," "second," etc., used herein are for descriptive purposes only and should not be construed as indicating or implying relative importance, nor should they be construed as implicitly specifying the number of technical features indicated. Features specified as "first" or "second" may expressly or implicitly indicate that at least one of those features is included.

[0021] A process for preparing a modified nonwoven fabric suitable for inkjet printing includes the following steps: S1, preparing the nonwoven fabric: Fibers are prepared in the following weight proportions: 4-7 parts wood pulp fiber, 5-12 parts resin fiber, 3-5 parts bamboo charcoal fiber, and 2-3 parts viscose fiber. The fibers are mixed, opened, combed, hydroentangled, or needle-punched to produce a nonwoven fabric with a basis weight of 60-150 g / m²; S2, modifying the nonwoven fabric: The nonwoven fabric is immersed in a modifying slurry, allowing the slurry to fill the gaps in the nonwoven fabric. Afterward, it is extruded using two rollers and dried in a drying zone to produce the modified nonwoven fabric. The modifying slurry comprises the following components in parts by weight: 5-10 parts calcium carbonate powder, 20-32 parts adhesive, 0.5-2.4 parts coupling agent, and 0.5-1.5 parts dispersant. The basis weight increase of the modified nonwoven fabric is 25-45 g / m². g / ㎡; S3, Preparation of base color coating: Roller-coating the base color slurry onto the upper surface of the modified nonwoven fabric and smoothing it. After the base color slurry dries, it forms a base color coating that is easy to inkjet print. The base color slurry includes the following weight groups: 5-12 parts of nano titanium dioxide, 20-28 parts of adhesive, 0.6-1.35 parts of coupling agent, and 0.3-0.5 parts of dispersant.

[0022] Example 1: A process for preparing modified nonwoven fabric suitable for inkjet printing includes the following steps: S1, preparing nonwoven fabric: preparing fibers according to the following weight parts: 4 parts wood pulp fiber, 5 parts resin fiber, 3 parts bamboo charcoal fiber, and 2 parts viscose fiber. The fibers are mixed, opened, combed, and hydroentangled to produce a nonwoven fabric with a basis weight of 60 g / m²; S2, nonwoven fabric modification treatment: immersing the nonwoven fabric in a modified slurry, allowing the modified slurry to fill the gaps in the nonwoven fabric, then extruding it through a two-roller press and drying it in a drying zone to produce a basis weight of 85 g / m². / ㎡ modified nonwoven fabric; the modified slurry includes the following components by weight: 5 parts calcium carbonate powder, 20 parts adhesive, 0.5 parts coupling agent, and 0.5 parts dispersant; S3, preparation of base color coating: the base color slurry is roller-coated onto the upper surface of the modified nonwoven fabric and smoothed. After the base color slurry dries, it forms a base color coating that is easy for inkjet printing; the base color slurry includes the following components by weight: 5 parts nano titanium dioxide, 20 parts adhesive, 0.6 parts coupling agent, and 0.3 parts dispersant. The particle size of the nano titanium dioxide is 10-50nm. The final modified nonwoven fabric has a total basis weight of 100g / ㎡ and a total thickness of 0.2mm.

[0023] Example 2: A process for preparing a modified nonwoven fabric suitable for inkjet printing includes the following steps: S1, preparing the nonwoven fabric: 7 parts wood pulp fiber, 12 parts resin fiber, 5 parts bamboo charcoal fiber, 3 parts viscose fiber, and 4 parts polyester fiber are prepared according to the following weight proportions. The fibers are mixed, opened, combed, and needle-punched to produce a nonwoven fabric with a basis weight of 150 g / m²; S2, modifying the nonwoven fabric: the nonwoven fabric is immersed in a modifying slurry, allowing the slurry to fill the gaps in the nonwoven fabric. Afterward, it is processed by double-roll extrusion and then dried in a drying zone to produce a modified nonwoven fabric with a basis weight of 195 g / m²; the modifying slurry comprises the following weight proportions... Components: 10 parts calcium carbonate powder, 20 parts bamboo pulp fiber, 32 parts adhesive, 2.4 parts coupling agent, and 1.5 parts dispersant; S3, Preparation of base color coating: Roller-coating the base color slurry onto the upper surface of the modified nonwoven fabric and smoothing it. After drying, the base color slurry forms a base color coating suitable for inkjet printing. The base color slurry comprises the following components by weight: 12 parts nano titanium dioxide, 5 parts precipitated barium sulfate powder, 0.35 parts defoamer, 28 parts adhesive, 1.35 parts coupling agent, and 0.5 parts dispersant. The particle size of the nano titanium dioxide is 10-50 nm, and the particle size of the precipitated barium sulfate powder is 200-400 nm. The final modified nonwoven fabric has a total basis weight of 225 g / m² and a total thickness of 0.4 mm.

[0024] Example 3: A process for preparing a modified nonwoven fabric suitable for inkjet printing includes the following steps: S1, preparing the nonwoven fabric: 5.5 parts wood pulp fiber, 8.5 parts resin fiber, 4 parts bamboo charcoal fiber, 2.5 parts viscose fiber, and 3 parts polyester fiber are prepared according to the following weight proportions. The fibers are mixed, opened, combed, and hydroentangled to produce a nonwoven fabric with a basis weight of 105 g / m²; S2, modifying the nonwoven fabric: immersing the nonwoven fabric in a modifying slurry, allowing the slurry to fill the gaps in the nonwoven fabric, then extruding it through a double roller and drying it in a drying zone to produce a modified nonwoven fabric with a basis weight of 140 g / m²; the modifying slurry comprises... The following components by weight are used: 7.5 parts calcium carbonate powder, 12 parts bamboo pulp fiber, 26 parts adhesive, 1.4 parts coupling agent, and 1 part dispersant; S3, Preparation of the base color coating: The base color slurry is roller-coated onto the upper surface of the modified nonwoven fabric and smoothed. After drying, the base color slurry forms a base color coating that is easy for inkjet printing. The base color slurry includes the following components by weight: 8.5 parts nano titanium dioxide, 3.5 parts precipitated barium sulfate powder, 0.25 parts defoamer, 24 parts adhesive, 1 part coupling agent, and 0.4 parts dispersant. The particle size of the nano titanium dioxide is 10-50 nm, and the particle size of the precipitated barium sulfate powder is 200-400 nm. The final modified nonwoven fabric has a total basis weight of 160 g / m² and a total thickness of 0.32 mm.

[0025] Example 4: A process for preparing a modified nonwoven fabric suitable for inkjet printing includes the following steps: S1, preparing the nonwoven fabric: 5.5 parts wood pulp fiber, 8.5 parts resin fiber, 4 parts bamboo charcoal fiber, 2.5 parts viscose fiber, and 2 parts polyester fiber are prepared according to the following weight proportions. The fibers are mixed, opened, combed, and hydroentangled to produce a nonwoven fabric with a basis weight of 110 g / m²; S2, modifying the nonwoven fabric: the nonwoven fabric is immersed in a modifying slurry, allowing the slurry to fill the gaps in the nonwoven fabric. Afterward, it is processed by double-roll extrusion and then dried in a drying zone to produce a modified nonwoven fabric with a basis weight of 150 g / m²; the modifying slurry package... The modified nonwoven fabric comprises the following components by weight: 7.5 parts calcium carbonate powder, 5 parts bamboo pulp fiber, 26 parts adhesive, 1.4 parts coupling agent, and 1 part dispersant; S3, Preparation of the base color coating: The base color slurry is roller-coated onto the upper surface of the modified nonwoven fabric and smoothed. After drying, the base color slurry forms a base color coating that is easy for inkjet printing. The base color slurry comprises the following components by weight: 8.5 parts nano titanium dioxide, 2 parts precipitated barium sulfate powder, 0.15 parts defoamer, 24 parts adhesive, 1 part coupling agent, and 0.4 parts dispersant. The particle size of the nano titanium dioxide is 10-50 nm, and the particle size of the precipitated barium sulfate powder is 200-400 nm. The final modified nonwoven fabric has a total basis weight of 165 g / m² and a total thickness of 0.35 mm.

[0026] Example 5: A process for preparing a modified nonwoven fabric suitable for inkjet printing includes the following steps: S1. Preparing the nonwoven fabric: Fibers are prepared in the following weight parts: 5.5 parts wood pulp fiber, 8.5 parts resin fiber, 4 parts bamboo charcoal fiber, 2.5 parts viscose fiber, and 3 parts polyester fiber. The above fibers are mixed, opened, combed, and hydroentangled to form a nonwoven fabric with a basis weight of 105 g / m². The lower surface of the nonwoven fabric is melt-blown, and a melt-blown layer with a basis weight of 30 g / m² is formed on the lower surface of the nonwoven fabric after melt-blowing. During melt-blowing, the polymer melt in the melt-blowing die includes the following weight parts: 5 parts polypropylene fiber and 2 parts ES adhesive fiber. The melt flow index of the polymer melt is 90 g / 10 min, the temperature of the melt-blowing die is 195°, the air jet angle in the melt-blowing die is 40°, the pressure of the hot air in the melt-blowing die is 0.1 MPa, and the polymer melt extrusion rate is 0.2 g / hole / min. After melt-blowing, hot rolling is performed. S2. Nonwoven fabric modification treatment: The nonwoven fabric is immersed in the modified slurry, which fills the gaps in the nonwoven fabric. After being processed by double roller extrusion, it is dried in the drying zone to produce a modified nonwoven fabric with a basis weight of 170 g / m². The modified slurry includes the following components by weight: 7.5 parts calcium carbonate powder, 12 parts bamboo pulp fiber, 26 parts adhesive, 1.4 parts coupling agent, and 1 part dispersant. S3. Preparation of base color coating: The base color slurry is roller-coated onto the upper surface of the modified nonwoven fabric and smoothed. After the base color slurry dries, it forms a base color coating that is easy to inkjet print. The base color slurry includes the following components by weight: 9 parts nano titanium dioxide, 4 parts precipitated barium sulfate powder, 0.25 parts defoamer, 24 parts adhesive, 1 part coupling agent, and 0.4 parts dispersant. The particle size of the nano titanium dioxide is 10-50 nm, and the particle size of the precipitated barium sulfate powder is 200-400 nm. The final modified nonwoven fabric has a total weight of 190 g / m² and a total thickness of 0.38 mm.

[0027] Example 6: The difference between this embodiment and Embodiment 5 is as follows: In step S1, the lower surface of the nonwoven fabric is subjected to meltblown treatment, and a meltblown layer with a basis weight of 50 g / m² is formed on the lower surface of the nonwoven fabric after meltblown treatment; during meltblown, the polymer melt in the meltblown die head includes the following components by weight: 8 parts of polypropylene fiber and 3 parts of ES adhesive fiber, the melt flow index of the polymer melt is 120 g / 10 min, the temperature of the meltblown die head is 205°, the air jet angle in the meltblown die head is 35°, the pressure of the hot air in the meltblown die head is 0.18 MPa, and the polymer melt extrusion rate is 0.4 g / hole / min. After meltblown, it is subjected to hot rolling treatment; in step S2, after being processed by double roller extrusion, it enters the drying zone for drying to produce a modified nonwoven fabric with a basis weight of 180 g / m²; in step S3, the total basis weight of the finally obtained modified nonwoven fabric is 200 g / m², and the total thickness is 0.42 mm.

[0028] Example 7: The difference between this embodiment and embodiment 5 is that: in step S1, the lower surface of the nonwoven fabric is subjected to meltblown treatment, and a meltblown layer with a basis weight of 40 g / m² is formed on the lower surface of the nonwoven fabric after meltblown treatment; during meltblown, the polymer melt in the meltblown die head includes the following components by weight: 6.5 parts of polypropylene fiber, 2.5 parts of ES adhesive fiber, the melt flow index of the polymer melt is 105 g / 10 min, the temperature of the meltblown die head is 200°, the air jet angle in the meltblown die head is 37°, the pressure of the hot air in the meltblown die head is 0.14 MPa, the polymer melt extrusion rate is 0.3 g / hole / min, and hot rolling treatment is performed after meltblown; In step S2, the double rollers are configured in two sets: a first double roller and a second double roller. A pre-drying zone is provided between the first and second double rollers. The nonwoven fabric base layer, impregnated with the modified slurry, passes sequentially through the first double roller, the pre-drying zone, the second double roller, and the drying zone. After passing through the pre-drying zone, the modified slurry in the nonwoven fabric reaches a basic hardening stage. Then, it enters the second double roller and finally reaches a fully hardened stage in the drying zone. The roller surface corresponding to the lower side of the nonwoven fabric in the second double roller has an array of spherical protrusions. After passing through the second double roller, an array of spherical concave holes are formed on the lower surface of the nonwoven fabric. The depth of the spherical concave holes is 0.25-0.35 to the total thickness of the nonwoven fabric after modification in step S2. After extrusion by the two sets of double rollers, a modified nonwoven fabric with a basis weight of 170 g / m² is produced. In step S3, the final modified nonwoven fabric has a total basis weight of 190 g / m² and a total thickness of 0.4 mm.

[0029] In the seven embodiments above: the adhesive is water-based acrylic resin, the coupling agent is silane coupling agent (KH550), the dispersant is ammonium salt dispersant (e.g., polyacrylate ammonium salt dispersant), and the defoamer is mineral oil defoamer (e.g., polyether-modified silicone oil defoamer); the particle size of the calcium carbonate powder is 8-12 μm. All the above adhesives, coupling agents, dispersants, defoamers, and other raw materials involved in the above embodiments were directly purchased.

[0030] The modified nonwoven fabric prepared through the above embodiments exhibits superior overall hardness and wrinkle resistance compared to ordinary nonwoven fabrics. Simultaneously, its extensibility, light transmittance, and water absorption are reduced, resulting in improved dimensional stability and opacity. When laminated with boards using water-based environmentally friendly adhesives, the adhesive cannot penetrate the modified nonwoven fabric. The base coating is white and smooth, making it ideal for inkjet printing. The modified nonwoven fabric is also resilient, allowing for winding and right-angle bending, facilitating processing and transportation. This modified nonwoven fabric itself does not contain formaldehyde, making it very environmentally friendly. Furthermore, the presence of bamboo charcoal fiber in the fabric allows it to absorb formaldehyde emitted from the boards during lamination, improving the environmental friendliness of the boards.

[0031] In Examples 2-7, nano-titanium dioxide and precipitated barium sulfate powder are used in the base color paste. By utilizing the particle size difference between the two particles, the surface roughness of the final base color coating is greater than that of nano-titanium dioxide alone in Example 1. This roughness can increase the surface area of ​​inkjet printing, improve the adhesion between ink and base color coating, and make the inkjet printed pattern clearer and with better color.

[0032] In Examples 5-7, a meltblown layer is laminated onto the surface of the nonwoven fabric. The upper and lower surfaces of the laminated nonwoven fabric have different porosities. The different porosities result in different amounts of modified slurry absorbed after entering the fabric. The nonwoven fabric has a higher content of modified slurry, greater hardness, higher flatness, and stronger opacity, leading to better inkjet printing results after preparing a base color coating on this surface. In contrast, the meltblown layer has a lower content of modified slurry, better toughness, and relatively higher water absorption. The lower surface of the meltblown layer is laminated to the board using a water-based environmentally friendly adhesive. The adhesive can better penetrate the meltblown layer but cannot penetrate the nonwoven fabric layer, which improves the composite strength of the meltblown layer and the board while effectively preventing the adhesive from penetrating the nonwoven fabric. Moreover, the meltblown layer made of polypropylene fiber has better sound insulation, which improves the sound insulation of the board after lamination.

[0033] In Example 7, a process of one-time extrusion, pre-drying, secondary extrusion, and drying is adopted to eliminate the internal stress of the modified slurry during the hardening process and prevent the modified nonwoven fabric from cracking. At the same time, secondary rolling is performed in the basic hardening stage to make the surface of the nonwoven fabric smoother, which is conducive to the preparation of a smoother base color coating. During the second double-roll extrusion, spherical concave holes are formed on the lower side of the modified nonwoven fabric. The spherical concave holes can enhance the bonding surface area when the modified nonwoven fabric and the board are bonded together with glue, improve the bonding strength, and further improve the sound insulation effect.

[0034] In the description of this invention, it should be understood that the directions or positional relationships indicated by up, down, left, right, inner end, outer end, one end, and the other end are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the purpose of more clearly describing the technical solutions of this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and should not be construed as limiting this invention.

[0035] Although specific embodiments of the invention have been described in detail herein, they are given for illustrative purposes only and should not be construed as limiting the scope of the invention. Various substitutions, alterations, and modifications can be conceived without departing from the spirit and scope of the invention.

Claims

1. A process for preparing modified nonwoven fabrics that are easy to inkjet print, characterized in that, Includes the following steps: S1. Preparation of nonwoven fabric: Prepare the fibers according to the following weight parts: 4-7 parts wood pulp fiber, 5-12 parts resin fiber, 3-5 parts bamboo charcoal fiber, and 2-3 parts viscose fiber. Mix the above fibers, open them, comb them, spun them into a web, or needle punch them to make nonwoven fabric. S2. Nonwoven fabric modification treatment: The nonwoven fabric is immersed in the modification slurry, so that the modification slurry fills the gaps in the nonwoven fabric. After being processed by double roller extrusion, it enters the drying zone to dry and produce modified nonwoven fabric. The modified slurry comprises the following components by weight: 5-10 parts calcium carbonate powder, 20-32 parts adhesive, 0.5-2.4 parts coupling agent, and 0.5-1.5 parts dispersant; the modified slurry also contains 5-20 parts by weight of bamboo pulp fiber; The double rollers are configured in two sets, namely the first double roller and the second double roller, with a pre-drying zone between the first double roller and the second double roller. The nonwoven fabric base layer impregnated with the modified slurry passes through the first double roller, the pre-drying zone, the second double roller, and the drying zone in sequence. After passing through the pre-drying zone, the modified slurry in the nonwoven fabric reaches the basic hardening stage, and then enters the second double roller, finally reaching the fully hardened stage in the drying zone. The roller surface of the second double roller, corresponding to the lower side of the nonwoven fabric, has an array of spherical protrusions. After passing through the second double roller, an array of spherical concave holes are formed on the lower surface of the nonwoven fabric. S3. Preparation of base color coating: The base color slurry is roller-coated onto the upper surface of the modified nonwoven fabric and smoothed. After the base color slurry dries, a base color coating that is easy to inkjet print is formed. The base color slurry includes the following components by weight: 5-12 parts of nano titanium dioxide, 20-28 parts of adhesive, 0.6-1.35 parts of coupling agent, and 0.3-0.5 parts of dispersant.

2. The preparation process of a modified nonwoven fabric suitable for inkjet printing according to claim 1, characterized in that, The lower surface of the nonwoven fabric obtained in step S1 is subjected to meltblown treatment, and a meltblown layer is formed on the lower surface of the nonwoven fabric after meltblown treatment. During meltblowing, the polymer melt inside the meltblowing die includes the following components by weight: 5-8 parts polypropylene fiber, 2-3 parts ES adhesive fiber, the melt flow index of the polymer melt is 90-120 g / 10 min, the temperature of the meltblowing die is 195-205℃, the air jet angle inside the meltblowing die is 35-40°, the pressure of the hot air flow inside the meltblowing die is 0.1-0.18 MPa, and the polymer melt extrusion rate is 0.2-0.4 g / hole / min.

3. The preparation process of a modified nonwoven fabric suitable for inkjet printing according to claim 2, characterized in that, The nonwoven fabric obtained in step S1 has a basis weight of 60-150 g / m², the meltblown layer has a basis weight of 30-50 g / m², and the total basis weight of the nonwoven fabric after meltblown treatment is 90-200 g / m²; after meltblown treatment, hot rolling treatment is performed.

4. The preparation process of a modified nonwoven fabric suitable for inkjet printing according to claim 1, characterized in that, The weight gain of the modified nonwoven fabric in step S2 is 25-45 g / m².

5. The preparation process of a modified nonwoven fabric suitable for inkjet printing according to claim 1, characterized in that, The ratio of the depth of the spherical concave hole to the total thickness of the nonwoven fabric after modification in step S2 is 0.25-0.

35.

6. The preparation process of a modified nonwoven fabric suitable for inkjet printing according to claim 1, characterized in that, In step S3, the base color slurry also includes the following components by weight: 2-5 parts of precipitated barium sulfate powder and 0.15-0.35 parts of defoamer; The nano-titanium dioxide has a particle size of 10-50 nm, and the precipitated barium sulfate powder has a particle size of 200-400 nm.