Preparation process of waterproof cloth

Abstract

The invention relates to a preparation process of waterproof cloth, which comprises the following steps: S1, positioning the pattern position of the cloth on a machine table, and applying a curable water-based slurry on the machine table corresponding to the edge of the cloth; the edge of the cloth is provided with a hollow structure or a porous structure; s2, before the primary curable water-based slurry is completely dried, the cloth is flatly laid on a machine table in an aligned mode, then secondary curable water-based slurry is coated in a silk-screen printing mode, and the secondary curable water-based slurry and the primary curable water-based slurry coincide in position; s3, stripping the cloth from the machine table, and drying to obtain the waterproof cloth. According to the method, a whole-surface bonding mode is not needed, on the basis that the original performance of the waterproof cloth is not affected, coating falling caused by edge tilting of the waterproof cloth can be effectively avoided, and meanwhile the problems that according to a conventional edge gluing technology, adhesive permeability and interlayer adhesive force are poor, and the edge covering effect is poor are solved.

Description

Technical Field

[0001] The invention relates to the technical field of textiles, and in particular to a preparation process of a waterproof cloth. Background Art

[0002] Existing waterproof cloth can effectively prevent water droplets from penetrating due to surface tension or dense weaving surface, but it also makes it more difficult for slurry to adhere. After a period of use, the edges of the waterproof cloth often curl up, causing the coating to easily fall off the cloth, which in turn affects the appearance and service life of the waterproof cloth and cannot meet people's needs.

[0003] Some existing technologies have studied some methods to improve the warping of fabric edges and avoid coating shedding, such as using other physical sewing methods such as sewing to process the edges of waterproof cloth to overcome the above problems, but this method has the disadvantages of high labor cost and cutting waste. For example, Chinese patent CN114393898A discloses a preparation process of a double-layer laminated PVC composite film, which prints colors and patterns on the mesh of the middle layer, and the mesh is laminated with a transparent PVC film on both sides by coating glue, which can solve the problem that the color or pattern on the surface of the mesh is easy to wear or fall off, and improve its use effect and use experience. However, due to the method of bonding the mesh with full-surface glue on both sides of the mesh, the basic performance of the mesh itself is inevitably affected, such as the air permeability of the mesh is significantly reduced, and the problem of edge warping has not been significantly improved. If the edge glue coating method is further used for bonding, the glue permeability after gluing is poor, which leads to a small area where the glue can adhere, poor interlayer adhesion, and still cannot effectively solve the problems of edge warping. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a preparation process of a waterproof cloth.

[0005] The technical solution adopted by the present invention is:

[0006] The present invention provides a process for preparing a waterproof cloth, comprising the following steps:

[0007] S1. Position the pattern of the fabric on the machine, and apply a layer of curable water-based slurry on the machine corresponding to the edge of the fabric;

[0008] The edge of the cloth has a hollow structure or a porous structure;

[0009] S2. Before the first layer of curable water-based slurry is completely dry, the cloth is aligned and laid flat on the machine table, and then a second layer of curable water-based slurry is applied by screen printing, and the second layer of curable water-based slurry overlaps with the first layer of curable water-based slurry;

[0010] S3, peeling the fabric from the machine and drying it to obtain the waterproof fabric.

[0011] The present invention proposes a preparation process of a waterproof cloth. Firstly, the present invention performs a hollowing treatment on the edge of the pattern of the cloth in advance (if the fabric itself has a porous structure, no treatment is required), which is beneficial to the penetration of a curable aqueous slurry and improves the adhesion between the first curable aqueous slurry and the cured coating of the second curable aqueous slurry; secondly, the present invention adjusts the coating timing of the second curable aqueous slurry to reduce the adverse effect on the interlayer adhesion, thereby avoiding the problems of imprint flow and unclear boundaries caused by the second coating of the slurry when the first curable aqueous slurry is not dry enough, or the problems of uneven surface and failure to firmly bond caused by the second coating of the slurry when the degree of dryness is too high; finally, the present invention can remove the waterproof cloth from the machine in time through the dovetail clamp structure formed between the two curable aqueous slurries, which can further ensure the curing and hemming effect. The present invention does not need to adopt the whole-surface bonding method. It can effectively avoid the coating shedding caused by the edge warping of the waterproof cloth without affecting the original performance of the waterproof cloth. At the same time, it avoids the problems of adhesive permeability, poor interlayer adhesion and poor hemming effect existing in the conventional edge gluing process, thereby extending the beauty and service life of the waterproof cloth.

[0012] Preferably, in step S1, the outer edge of the curable aqueous slurry extends 0.1-2 mm relative to the edge of the cloth.

[0013] Preferably, the hollow structure or the porous structure is 0.1-1 mm away from the edge of the cloth.

[0014] Preferably, in step S1, the applying is performed by hollow printing.

[0015] Preferably, in step S1, the viscosity of the curable aqueous slurry at 25°C is 200-2000 mPa·s.

[0016] Preferably, in step S1, the thickness of the applied layer of curable aqueous slurry is not less than the thickness of the cloth.

[0017] Preferably, in step S2, before completely drying means: the one layer of curable aqueous slurry is dried at temperature T, the drying time is H1, and the actual drying time of the one layer of curable aqueous slurry at temperature T is H2, then 0.7H2≤H1≤0.92H2.

[0018] More preferably, 0.75H2≤H1≤0.9H2.

[0019] Preferably, in step S1, the content of the polyether-modified silicone oil leveling agent in the first curable aqueous slurry is 0.1-0.2 wt %, and the content of the polyether-modified silicone oil leveling agent in the second curable aqueous slurry is 0.3-0.6 wt %.

[0020] Preferably, in step S2, the viscosity of the second curable aqueous slurry at 25°C is 1000-10000 mPa·s. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is further illustrated and described below through specific implementation methods.

[0022] An embodiment of the present invention provides a process for preparing a waterproof cloth, comprising the following steps:

[0023] S1. Position the pattern of the fabric on the machine, and apply a layer of curable water-based slurry on the machine corresponding to the edge of the fabric;

[0024] The edge of the fabric has a hollow structure or a porous structure;

[0025] S2. Before the first layer of curable water-based slurry is completely dry, the cloth is aligned and laid flat on the machine table, and then a second layer of curable water-based slurry is applied by screen printing, and the second layer of curable water-based slurry overlaps with the first layer of curable water-based slurry;

[0026] S3, peeling the fabric off the machine and drying it to obtain the waterproof fabric.

[0027] In the present invention, before the slurry is applied, the edge of the non-porous fabric needs to be pre-treated to make it hollow, so as to ensure the permeability of the first curable aqueous slurry and improve the interlayer adhesion between it and the second curable aqueous slurry. Conventional methods in the art can be used, such as laser cutting, without special restrictions.

[0028] In a preferred embodiment of the present invention, in step S1, the outer edge of a curable aqueous slurry extends 0.1-2 mm relative to the edge of the cloth. In the present invention, the outer edge of a curable aqueous slurry coating area needs to extend a certain distance relative to the edge of the cloth. If the extension distance is too small, it cannot be guaranteed that the edge of the cloth can be coated, which may easily lead to poor hemming effect; if the extension distance is too large, additional cutting processing is required after curing, resulting in waste of manpower and raw materials. For example, the extension distance of the outer edge of a curable aqueous slurry relative to the edge of the cloth can be any value of 0.1mm, 0.3mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, etc., but is not limited to the above-mentioned values.

[0029] In a preferred embodiment of the present invention, the hollow structure or porous structure is 0.1-1mm away from the edge of the fabric. In the present invention, a suitable width is required between the hollow structure or porous structure and the edge of the fabric, which can not only avoid the original basic properties of the waterproof fabric such as waterproofness and air permeability when the area coated with a curable aqueous slurry is too large, but also avoid the problems of insufficient adhesion area between the two curable aqueous slurries and too low interlayer adhesion when the area coated with a curable aqueous slurry is too small. For example, the distance between the hollow structure or porous structure and the edge of the fabric can be any value of 0.1mm, 0.2mm, 0.4mm, 0.6mm, 0.8mm, 1mm, etc., without special restrictions.

[0030] In a preferred embodiment of the present invention, in step S1, the application is performed by hollow printing. In the present invention, a layer of curable aqueous slurry is applied to the machine by hollow printing, which has high alignment efficiency and is beneficial to the coating, pore filling and penetration of a layer of curable aqueous slurry.

[0031] In a preferred embodiment of the present invention, in step S1, the viscosity of a curable aqueous slurry at 25°C is 200-2000mPa·s. In the present invention, the viscosity of the applied curable aqueous slurry needs to be controlled to ensure that it flows and fully fills and penetrates the hollowed-out portion of the edge of the cloth. If the viscosity is too small, the fluidity of the curable aqueous slurry is too large, and it is easy to flow, which is not conducive to the printing quality; if the viscosity is too large, it is not conducive to the penetration of the curable aqueous slurry into the cloth, and it is difficult to peel off from the machine later. For example, the viscosity of a curable aqueous slurry at 25°C can be any value of 200mPa·s, 500mPa·s, 800mPa·s, 1000mPa·s, 1200mPa·s, 1500mPa·s, 1800mPa·s, 2000mPa·s, etc., without special restrictions.

[0032] In a preferred embodiment of the present invention, in step S1, the thickness of the applied layer of curable aqueous slurry is not less than the thickness of the cloth. In the present invention, the thickness of the applied layer of curable aqueous slurry is controlled to be not less than the thickness of the cloth to ensure the penetration effect of the first layer of curable aqueous slurry and the curing and hemming effect of the first layer of curable aqueous slurry and the second layer of curable aqueous slurry. However, the applied thickness should not be too thick, otherwise the leveling speed of the first layer of curable aqueous slurry is too fast, and the subsequent application of the second layer of curable aqueous slurry is easy to overflow, which is not conducive to curing and molding.

[0033] In a preferred embodiment of the present invention, in step S2, before complete drying means: a layer of curable aqueous slurry is dried at a temperature of T, the drying time is H1, and the actual drying time of a layer of curable aqueous slurry at a temperature of T is H2, then 0.7H2≤H1≤0.92H2. During the drying process, the viscosity of the slurry system is continuously increased. In order to ensure that the interlayer adhesion, peel strength and other properties of the final two layers of slurry are easily within the required range, the coating timing of the two layers of curable aqueous slurry needs to be strictly controlled. In the present invention, the definition of a layer of curable aqueous slurry not being completely dried has three functions: (1) if 0.7H2≤H1≤0.92H2, it means that the layer of curable aqueous slurry is in a suitable state of being cured but not completely cured, and its viscosity increases to the point that the second layer of curable aqueous slurry is not easy to penetrate under the action of the scraper, and the adhesion between the first layer of curable aqueous slurry and the second layer of curable aqueous slurry is high; (2) if H1<0.7H2, it means that the curing degree of the first layer of curable aqueous slurry is not enough, and at this time, printing the second layer of curable aqueous slurry is not necessary. The material will squeeze the first curable water-based slurry, causing the first curable water-based slurry to overflow, and because the first curable water-based slurry is in contact with the machine and is not sufficiently cured, when the cloth is peeled off from the machine after printing the second curable water-based slurry, part of the first curable water-based slurry will remain on the machine, affecting the integrity of the hemming structure and the hemming effect; (3) If H1>0.92H2, it means that the curing degree of the first curable water-based slurry is too high, which will make it difficult to peel the cloth from the machine surface and easily destroy the hemming effect. For example, when the actual drying time H2 of the first curable water-based slurry at T=25°C is 20min, the drying time H1 is 14min-18.4min. Specifically, the drying time H1 can be any value of 14min, 14.8min, 15.6min, 16.4min, 17.2min, 18min, 18.4min, etc., but is not limited to the above-mentioned values.

[0034] In a more preferred embodiment of the present invention, 0.75H2≤H1≤0.9H2. In the present invention, further screening the range of the drying time H1 is conducive to better improving the interlayer adhesion of the two layers of curable aqueous slurries, and the effect of peeling the dovetail clip structure formed by the two layers of curable aqueous slurries from the machine. For example, when the actual drying time H2 of a layer of curable aqueous slurry at T=25°C is 20 minutes, the drying time H1 is 15 minutes to 18 minutes. Specifically, the drying time H1 can be any value of 15 minutes, 15.5 minutes, 16 minutes, 16.5 minutes, 17 minutes, 17.5 minutes, 18 minutes, etc., but is not limited to the above-mentioned values.

[0035] In a preferred embodiment of the present invention, in step S1, the content of the polyether-modified silicone oil leveling agent in the first curable aqueous slurry is 0.1-0.2wt%, and the content of the polyether-modified silicone oil leveling agent in the second curable aqueous slurry is 0.3-0.6wt%. In the present invention, a lower content of the polyether-modified silicone oil leveling agent in the first curable aqueous slurry is conducive to leveling and penetration, but can avoid negative effects on interlayer adhesion; an appropriate amount of the polyether-modified silicone oil leveling agent in the second curable aqueous slurry has not only the effects of leveling and penetration, but also can improve interlayer adhesion. For example, the content of the polyether-modified silicone oil leveling agent in one layer of curable aqueous slurry can be any value among 0.1wt%, 0.15wt%, 0.2wt%, etc.; the content of the polyether-modified silicone oil leveling agent in the second layer of curable aqueous slurry can be any value among 0.3wt%, 0.35wt%, 0.4wt%, 0.45wt%, 0.5wt%, 0.55wt%, 0.6wt%, etc.

[0036] In addition, the present invention does not impose any special restrictions on the raw material components of the one-stage / two-stage curable aqueous slurry, which can be directly purchased and used from the market. The present invention provides a typical curable aqueous slurry, which is composed of component A and component B in a weight ratio of 100:4-6, and component A, based on 100% by weight, includes: 90-92% of aqueous polyurethane dispersion, 0.1-0.3% of pH regulator, 0.4-0.5% of silicone defoamer, 0.8-1% of dispersant, 0.8-1% of polyether polyurethane thickener (PU thickener), 0.1-0.6% of polyether modified silicone oil leveling agent, 0.3-0.5% of acrylic copolymer thickener (PTF thickener), and 5-6% of propylene glycol; component B is an isocyanate curing agent. When used, component B is added to component A in proportion and stirred evenly, and then the coating operation can be carried out.

[0037] In a preferred embodiment of the present invention, in step S2, the viscosity of the second curable aqueous slurry at 25° C. is 1000-10000 mPa·s. In the present invention, the viscosity of the second curable aqueous slurry during coating is controlled to ensure good mixing with the first curable aqueous slurry during downward pressure coating, and the slurry layer can retain the original partially cured edge shape while having moderate fluidity, thereby achieving the purpose of improving interlayer adhesion.

[0038] Preparation Example: Preparation of curable water-based slurry

[0039] Preparation Example 1

[0040] A curable water-based slurry is composed of component A and component B in a weight ratio of 100:5. Component A, 100% by weight, includes: 91.3% waterborne polyurethane dispersion, 0.15% pH regulator, 0.45% silicone defoamer, 1% dispersant, 1% PU thickener, 0.15% polyether modified silicone oil leveling agent, 0.45% PTF thickener, 5-6% propylene glycol; component B is an isocyanate curing agent. When used, component B is added to component A in proportion and stirred evenly, and then coating can be carried out.

[0041] Preparation Example 2

[0042] The difference between this preparation example and preparation example 1 is that in this preparation example, no polyether-modified silicone oil leveling agent is added, and 0.15% of aqueous polyurethane dispersion is used to make up the difference. The other steps remain unchanged.

[0043] Preparation Example 3

[0044] The difference between this preparation example and preparation example 1 is that the 0.15% polyether-modified silicone oil leveling agent in preparation example 1 is replaced by 0.45% polyether-modified silicone oil leveling agent, and the amount of aqueous polyurethane dispersion is reduced by 0.3%. The other steps remain unchanged.

[0045] Preparation Example 4

[0046] The difference between this preparation example and preparation example 1 is that the 0.15% polyether-modified silicone oil leveling agent in preparation example 1 is replaced by 1% polyether-modified silicone oil leveling agent, and the amount of aqueous polyurethane dispersion is reduced by 0.85%. The remaining steps remain unchanged.

[0047] The viscosity of the samples prepared in Example 1-4 was tested and the results are shown in Table 1.

[0048] Viscosity test method: Use a rotary viscometer at T = 25°C and use a 100# rotor to measure the viscosity at 7.5 rpm.

[0049] Table 1

[0050] Preparation Example 1 Preparation Example 2 Preparation Example 3 Preparation Example 4 Initial viscosity / mPa·s 1450 1504 1426 1392

[0051] Example 1

[0052] Preparation Example 1 is used as a first curable aqueous slurry and Preparation Example 3 is used as a second curable aqueous slurry to prepare a waterproof cloth, including the following steps:

[0053] S1. Position the pattern of the fabric on the machine, and apply a layer of curable water-based slurry at the machine corresponding to the edge of the fabric by hollow printing;

[0054] The edge of the fabric has a hollow structure or a porous structure.

[0055] The outer edge of a curable aqueous slurry extends 0.15 mm relative to the edge of the fabric.

[0056] The hollow structure or porous structure is 0.5mm away from the edge of the fabric.

[0057] The thickness of a layer of curable water-based slurry applied shall not be less than the thickness of the cloth (the applied thickness shall be 1.1 times the thickness of the cloth).

[0058] S2. Before a layer of curable water-based slurry is completely dry (the actual drying time of a layer of curable water-based slurry at T = 25°C is 20 minutes, and the drying time is 14 minutes), the cloth is aligned and laid flat on the machine table, and then a second layer of curable water-based slurry is applied by screen printing, and the second layer of curable water-based slurry overlaps with the first layer of curable water-based slurry.

[0059] S3, peeling the fabric off the machine and drying it to obtain the waterproof fabric.

[0060] Example 2

[0061] The difference between this embodiment and embodiment 1 is that in step S2, the drying time of one layer of curable aqueous slurry is 15 minutes. The other steps remain unchanged.

[0062] Example 3

[0063] The difference between this embodiment and embodiment 1 is that in step S2, the drying time of one layer of curable aqueous slurry is 18 minutes. The other steps remain unchanged.

[0064] Example 4

[0065] The difference between this embodiment and embodiment 1 is that in step S2, the drying time of one layer of curable aqueous slurry is 18.4 minutes. The other steps remain unchanged.

[0066] Comparative Example 1

[0067] The difference between this comparative example and Example 1 is that in step S2, the drying time of one layer of curable aqueous slurry is 12 minutes. The other steps remain unchanged.

[0068] Comparative Example 2

[0069] The difference between this comparative example and Example 1 is that in step S2, the drying time of one layer of curable aqueous slurry is 20 minutes. The other steps remain unchanged.

[0070] Comparative Example 3

[0071] The difference between this comparative example and Example 1 is that Preparation Example 2 is used instead of Preparation Example 1 as a curable aqueous slurry. The other steps remain unchanged.

[0072] Comparative Example 4

[0073] The difference between this comparative example and Example 1 is that Preparation Example 3 is used as both the first and second curable aqueous slurries. The other steps remain unchanged.

[0074] Comparative Example 5

[0075] The difference between this comparative example and Example 1 is that Preparation Example 1 is used as both the first and second curable aqueous slurries. The other steps remain unchanged.

[0076] Comparative Example 6

[0077] The difference between this comparative example and Example 1 is that Preparation Example 4 is used instead of Preparation Example 3 as the second curable aqueous slurry. The other steps remain unchanged.

[0078] The waterproof fabrics prepared in Examples 1-4 and Comparative Examples 1-6 were subjected to performance tests, and the results are recorded in Table 2.

[0079] Washing resistance test: according to GB / T 22700-2008 standard;

[0080] Adhesion test between one and two layers of curable water-based slurry: according to GB / T 5210-2006 standard;

[0081] 180° peeling force test between a curable water-based slurry and a machine: according to GB2792-1998 standard;

[0082] Printability evaluation (visual inspection): Apply other water-based slurry on the original coating, repeat printing 7 times, place the printed sample in an oven, dry it at 50°C for 8 hours, and observe and judge.

[0083] Table 2

[0084]

[0085]

[0086] As can be seen from the data in Table 2, the coating curing and edge binding preparation process of Examples 1-4 of the present invention can effectively avoid the coating from falling off due to the warping of the edge of the waterproof cloth, and the interlayer adhesion is high, which prolongs the beauty and service life of the waterproof cloth. The data of Comparative Example 1 show that when the drying time of the first curable aqueous slurry is insufficient, it is in contact with the machine and is not sufficiently cured, which will cause part of the first curable aqueous slurry to remain on the machine when the cloth is peeled off from the machine after printing the second curable aqueous slurry, thereby affecting the integrity of the edge binding structure and the edge binding effect; while in Comparative Example 2, due to the excessive drying of the first curable aqueous slurry, the first and second curable aqueous slurries are difficult to be firmly bonded, and the cloth is also difficult to be peeled off from the surface of the machine, which ultimately destroys the edge binding effect. The results of Comparative Examples 3-6 show that the appropriate addition of the leveling agent in the preparation process of the present invention can be beneficial to the leveling and penetration of the first and second curable aqueous slurries, so as to achieve the effect of improving the interlayer adhesion. Too much or too little is not conducive to the edge binding effect of the final product.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A process for preparing a waterproof cloth, comprising the following steps: S1. Position the pattern of the fabric on the machine, and apply a layer of curable water-based slurry on the machine corresponding to the edge of the fabric; The edge of the cloth has a hollow structure or a porous structure; S2. Before the first layer of curable water-based slurry is completely dry, the cloth is aligned and laid flat on the machine table, and then a second layer of curable water-based slurry is applied by screen printing, and the second layer of curable water-based slurry overlaps with the first layer of curable water-based slurry; S3, peeling the fabric from the machine and drying it to obtain the waterproof fabric.

2. The process for preparing the waterproof cloth according to claim 1, characterized in that: In step S1, the outer edge of the curable aqueous slurry extends 0.1-2 mm relative to the edge of the cloth.

3. The process for preparing the waterproof cloth according to claim 1, characterized in that: The hollow structure or the porous structure is 0.1-1 mm away from the edge of the cloth.

4. The process for preparing the waterproof cloth according to claim 1, characterized in that: In step S1, the applying is performed by hollow printing.

5. The process for preparing the waterproof cloth according to claim 1, characterized in that: In step S1, the viscosity of the curable aqueous slurry at 25°C is 200-2000 mPa·s.

6. The process for preparing the waterproof cloth according to claim 1, characterized in that: In step S1, the thickness of the applied layer of curable aqueous slurry is not less than the thickness of the cloth.

7. The process for preparing the waterproof cloth according to claim 1, characterized in that: In step S2, before complete drying means: the one layer of curable aqueous slurry is dried at temperature T, the drying time is H1, and the actual drying time of the one layer of curable aqueous slurry at temperature T is H2, then 0.7H2≤H1≤0.92H2.

8. The process for preparing the waterproof cloth according to claim 7, characterized in that: 0.75H2≤H1≤0.9H2.

9. The process for preparing the waterproof cloth according to claim 1, characterized in that: In step S1, the content of the polyether-modified silicone oil leveling agent in the first curable aqueous slurry is 0.1-0.2 wt %, and the content of the polyether-modified silicone oil leveling agent in the second curable aqueous slurry is 0.3-0.6 wt %.

10. The process for preparing the waterproof cloth according to claim 1, characterized in that: In step S2, the viscosity of the second curable aqueous slurry at 25°C is 1000-10000 mPa·s.

Images