Anti-slurry-seepage foaming coating method for thin-weave fabric

Abstract

The invention relates to the technical field of textile fabric coatings, and discloses an anti-slurry-seepage foaming coating method for a thin-weave fabric. The method aims at solving the problem of how to prevent slurry from permeating to a non-coating surface to keep the original appearance during processing of the single-side foaming coating. The core of the technical scheme comprises the following steps: preparing foaming slurry taking ammonium stearate and silicon resin polyether compound emulsion as a foam stabilizer; during coating, the scraper is adjusted to be in a specific'second blade coating state ', that is, the scraper is translated for 2-2.5 cm on the same side in the coating direction, and then a gap of 0.5-1.5 mm is kept between the scraper and the coating roller, so that micro-pressure or suspended coating is realized. Through the synergistic effect of'regulating and blocking a pollution path by the state of the scraper 'and'enhancing foam stability and reducing a permeation source by the compound foam stabilizer', slurry permeation can be effectively avoided, and the texture and color of a non-coating surface are ensured to be as initial. The method can be further expanded into a multi-layer structure in which a priming layer, a shading layer, a covering layer and an anti-sticking layer are sequentially coated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of textile fabric coating finishing, in particular to a method for anti-seepage foaming coating of sparse fabric. BACKGROUND

[0002] In the field of high-end decorative fabric, double-sided different effect fabric and product requiring to maintain the original aesthetic quality of fabric, it is often necessary to perform functional treatment (such as light shielding, thickening, etc.) on only one side of the fabric, while the other side is required to completely retain the original texture, color and hand feeling of the base fabric. Foaming coating technology is one of the ideal choices for realizing single-sided functionalization due to its excellent light shielding property and fullness.

[0003] However, for fabrics with sparse structure, the existing foaming coating technology faces a fundamental challenge: during the coating process, the foaming slurry is prone to "seepage". That is, the liquid components in the slurry penetrate through the sparse interstitial space between fibers, reach and contaminate the non-coated side of the fabric. This contamination leads to two unacceptable defects:

[0004] Firstly, the yarns on the non-coated side are covered by the slurry, the original clear texture is blurred, the color is changed, and the value as the "appearance side" is lost;

[0005] Secondly, the seepage of the slurry will contaminate the equipment rollers and may cause secondary defects.

[0006] Although the existing technology attempts to alleviate this by increasing the viscosity of the slurry, it often comes at the cost of sacrificing the hand feeling and processing performance of the coating, and cannot completely eliminate the microscopic penetration on the non-coated side.

[0007] Therefore, how to completely prevent the penetration of the slurry to the non-coated side during the single-sided foaming coating process of sparse fabric, so as to absolutely guarantee the originality of the visual and tactile quality of the non-coated side, has become a technical problem that needs to be solved in this field. SUMMARY

[0008] The technical problem to be solved by the present application is how to effectively prevent the penetration of the slurry to the non-coated side during the single-sided foaming coating process of sparse fabric, so as to maintain the original texture and color of the base fabric on that side.

[0009] The technical solution adopted by the present application to solve the technical problem is:

[0010] A method for anti-seepage foaming coating of sparse fabric, characterized in that it comprises the following steps:

[0011] S1, preparing a foaming coating slurry, the foaming coating slurry at least comprising an aqueous acrylate emulsion, a covering filler, a compounded foam stabilizer and a crosslinking agent; wherein the compounded foam stabilizer is a compound of ammonium stearate emulsion and silicone polyether emulsion;

[0012] S2, mechanically foaming the foaming coating slurry to obtain a foaming slurry;

[0013] S3, feeding the loose fabric into a coating machine, and coating the foaming slurry on one side surface of the loose fabric by means of a doctor blade coating method;

[0014] wherein the doctor blade is arranged on the coating roller and is translated by a preset distance from a first doctor blade state in which the foaming slurry can contact and adhere to the surface of the coating roller when the foaming slurry leaks in the doctor blade coating process to a second doctor blade state on the same side of the coating direction.

[0015] S4, drying and setting the coated loose fabric.

[0016] In a further preferred technical solution, the preset distance is 2-2.5 cm; to realize micro-pressure coating, the doctor blade has a gap of 0.5-1.5 mm between the blade edge and the surface of the coating roller in the second doctor blade state.

[0017] In a further preferred technical solution, in the compounded foam stabilizer, the mass ratio of the ammonium stearate emulsion to the silicone polyether emulsion is (85-95):(5-15).

[0018] In a further preferred technical solution, the mass percentage content of the water-based acrylate emulsion is 60-70%, the mass percentage content of the covering filler is 10-15%, the mass percentage content of the compounded foam stabilizer is 10-15%, and the mass percentage content of the crosslinking agent is 2-3%, based on the total weight of the foaming coating slurry.

[0019] In a further preferred technical solution, in step S2, the foaming ratio of the foaming slurry is controlled to be 3.5-3.7.

[0020] In a further preferred technical solution, in step S1, the foaming coating slurry further comprises a thickening agent and a pH adjusting agent, and the viscosity is controlled to be 14000-18000 mPa·s after compounding.

[0021] In a further preferred technical solution, steps S3 and S4 are repeated at least twice to form a foaming primer layer and a foaming light-shielding layer on the loose fabric in turn.

[0022] In a further preferred technical solution, carbon black paste is further added to the foaming coating slurry for forming the foaming light-shielding layer, and the foaming ratio of the foaming slurry of this layer is 3.1-3.3.

[0023] In a further preferred technical solution, after forming the foaming light-shielding layer, a foaming cover layer is further coated, and the foaming ratio of the foaming slurry of this layer is 3.3-3.5.

[0024] Further preferred technical solutions, on the surface of the foaming cover layer, further coated with an anti-sticking layer and dried.

[0025] The beneficial effects of the present application are:

[0026] The beneficial effects of the present application are that, for the key defect of easy penetration and pollution of the slurry on the non-coated side of the single-side foaming coating of the thin tissue fabric, a set of synergistic technical solutions are provided, which are embodied in:

[0027] 1. A new "suspended scraping" mechanical state is established, which fundamentally eliminates the main external force that causes slurry penetration. Unlike the conventional purpose of controlling coating thickness by adjusting the gap, the present application adjusts the specific gap of 0.5-1.5 mm between the scraper and the coating roller by translating the scraper along the same side of the coating direction by a preset distance, so that the scraper is in a unique working state of "suspended" blade edge above the base fabric during coating. This state actively and effectively eliminates the vertical mechanical pressure of the scraper on the wet slurry and the thin base fabric, thereby cutting off the main mechanical path of slurry forced to penetrate into the fiber gap and penetrate to the non-coated side due to external extrusion.

[0028] 2. A "rigid-elastic synergistic" foam stabilization system is designed, which significantly reduces the amount of free liquid available for penetration. The present application uses a specific compound of ammonium stearate emulsion and silicone polyether emulsion as a foam stabilizer. This system not only promotes foaming by reducing surface tension, but more importantly, the silicone polyether forms a high-elasticity reinforcement layer at the foam liquid film interface, greatly improving the ability of the foam to resist mechanical shear forces during foaming, transportation and coating. This makes the foam remain intact and delay rupture during the coating stage, thereby reducing the generation of low-viscosity free liquid from the source, i.e., directly reducing the material itself that can be penetrated.

[0029] 3. The synergistic effect of the above two means forms a double anti-permeation mechanism of "blocking external force" and "stabilizing the body". The innovative "suspended scraping" state provides a non-extrusion coating environment for the slurry, while the "rigid-elastic synergistic" foam stabilization system enhances the internal stability of the slurry body in this environment. The two are not simply added together, but are indispensable to each other and together form a complete anti-permeation solution, effectively solving the problem of slurry penetration and non-coated side pollution that cannot be eliminated by a single means such as adjusting the scraper or changing the foam stabilizer.

[0030] 4. Ultimately achieve the goal of "single-sided processing, double-sided different effects" of high-quality processing. Based on the above synergistic technical scheme, the present application can successfully build a functional foaming coating (such as a light-shielding layer) on one side of the thin fabric while ensuring that the non-coated side is completely free from slurry penetration pollution. The fiber texture of the non-coated side is clearly visible, and the color and hand feel are maximized to maintain the original state of the base fabric, thereby perfectly meeting the stringent requirements of high-end applications for different functions and appearances on the front and back of the fabric. The comparative experiments in the specific embodiments also confirm that the present application method has achieved significant and unexpected results in preventing texture blurring and color change on the non-coated side compared to the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 Process flow chart of the anti-seepage slurry foaming coating method of the present application.

[0032] Figure 2 Schematic diagram of the relative position of the scraper and the coating roller and the anti-seepage slurry mechanism in the present application.

[0033] In the figure: 1 - base fabric, 2 - coating roller; 3 - first scraper position in scraping state, 4 - second scraper position in scraping state. DETAILED DESCRIPTION

[0034] The present application will be further described in detail below in combination with the drawings and examples. In the following example of an anti-seepage slurry foaming coating method for thin fabric, the process flow can be referred to Figure 1 , and the relative position of the scraper and the coating roller can be referred to Figure 2 .

[0035] (I) Two method examples

[0036] Example 1: Basic anti-seepage slurry foaming coating method

[0037] This example shows the complete process of single-layer foaming coating using the core means of the present application.

[0038] S1, prepare foaming primer layer slurry: according to mass percentage, take 65% of water-based acrylate emulsion with solid content of 48%, 13% of titanium white slurry compounded by 1:1 of rutile titanium dioxide and water, 12% of foam stabilizer (the mass ratio of ammonium stearate emulsion to silicone polyether emulsion is 95:5), 2.5% of blocked isocyanate crosslinking agent, and the rest is deionized water. Put the above materials into the stirring kettle.

[0039] S2, slurry pretreatment and foaming: stirring at 520 r / min, adding thickening agent and adjusting pH to 8.5 with ammonia water, adjusting the viscosity of the slurry to about 16000 mPa·s, and continuing to stir for 20 min. Then the slurry is transported to the foaming machine, and the foaming ratio is controlled to be 3.6 to obtain foaming slurry A.

[0040] S3, base fabric pretreatment: select 600D600D polyester plain fabric with warp and weft density of 4030, preheat and set at 160℃.

[0041] S4, knife coating (core step): deliver foaming slurry A to the coating machine. The key operation is to set the state of the knife: first translate the knife along the same side of the coating direction by 2.2 cm; then finely adjust the height of the knife to form a uniform gap of about 1 mm between the knife edge and the surface of the coating roller. Under this optimized "second knife coating state", coating is carried out at a speed of 25 m / min.

[0042] S5, gradient drying and setting: drying is carried out at a gradient temperature of 60℃→80℃→100℃→120℃→140℃→160℃(4 zones)→140℃→120℃→100℃ to obtain a single-layer foaming primer coating fabric.

[0043] Example 2: multi-layer composite impermeable slurry sunscreen coating method

[0044] This example is based on Example 1 and demonstrates the process of producing a multi-layer functional coating with sunscreen and protection functions.

[0045] After obtaining the first semi-finished product of Example 1, the following steps are continued:

[0046] S6, preparation and coating of foaming sunscreen layer: additional addition of 12% carbon black paste in the base slurry of Example 1, after uniform stirring, foaming (ratio 3.2) to obtain foaming slurry B. Keep the knife in the same "second knife coating state" as Example 1, coat slurry B on the primer layer and gradient dry.

[0047] S7, coating of foaming cover layer: coat foaming slurry A (foaming ratio adjusted to 3.4) on the sunscreen layer under the same knife state, and gradient dry.

[0048] S8, coating of anti-adhesion layer: mix 5% silicone smoothing agent with 95% water and thicken to a viscosity of about 220000 mPa·s, coat on the surface of the cover layer by anilox roller, and dry at a maximum temperature of 150℃ to obtain the final product.

[0049] (II) Component optimization and effect verification

[0050] Test the optimization of the complex ratio of foam stabilizer and its effect on impermeability

[0051] 1. Basic Formulation and Experimental Design:

[0052] The basic formulation of the foaming primer is as follows (by weight percentage): 60-70% water-based acrylic emulsion, 10-15% titanium dioxide paste, 2-3% end-capped isocyanate crosslinking agent, and 10-15% foam stabilizer. Three sets of experiments were conducted with the total amount of foam stabilizer remaining constant:

[0053] Group A (Preferred Group): Ammonium stearate emulsion: silicone polyether emulsion = 95:5.

[0054] Group B (Control Group): Ammonium stearate emulsion: silicone polyether emulsion = 90:10.

[0055] Group C (Control Group): Ammonium stearate emulsion: silicone polyether emulsion = 85:15.

[0056] 2. Performance Evaluation and Results:

[0057] Foam stability: Measured volume retention 30 minutes after foaming. A higher proportion of silicone polyether results in a longer foam lifespan. Group C foam is the most durable.

[0058] Foam structure: Microscopic observation shows that from group A to group C, the foam pore size tends to be smaller and more uniform, and the proportion of closed-cell structure increases, indicating that the liquid film is more complete and the free liquid phase is reduced.

[0059] Process and seepage prevention effect: The same substrate was coated under the same "second coating state". Group A (95:5) achieved the best balance between seepage prevention effect (cleanliness of the non-coated surface), slurry process viscosity, and drying efficiency, and was established as the preferred ratio. Although Groups B and C could further improve foam fineness, the system viscosity increased, and the drying energy consumption increased.

[0060] 3. Conclusion:

[0061] The compounding of ammonium stearate and silicone polyether in the range of 85:15 to 95:5 significantly improves the seepage prevention effect, with 95:5 being the optimal ratio. This confirms the scientific nature and optimizability of the compounding scheme of the present invention.

[0062] (III) Comprehensive Analysis of Comparison and Effect

[0063] To verify the necessity of the collaborative solution of the present invention, the following comparative examples were set up for comparison with Example 1, and the results are summarized in the table below:

[0064]

[0065] In this example, the single foam stabilizer was replaced with an equal amount (12%) of single ammonium stearate emulsion, and no silicone polyether emulsion was added. All other process parameters (total formulation, viscosity, foaming ratio 3.6, machine speed, drying curve, etc.) were strictly kept consistent with those in Example 1.

[0066] Mechanism conclusion:

[0067] 1. Comparative Example 1 showed the worst results, confirming that the traditional process has serious problems of slurry seepage and secondary pollution.

[0068] 2. Comparative Example 2 shows that using only the "second scraping state" can basically solve the problem of secondary contamination (clean back side), but has limited effect on improving vertical penetration.

[0069] 3. Comparative Example 3 shows that using only "95:5 compound foam stabilizer" can reduce penetration to some extent, but cannot avoid secondary pollution.

[0070] 4. Example 1 combines the two methods to synergistically achieve "cutting off the pollution path" (scraper state) and "reducing the source of infiltration" (compound foam stabilization), achieving unexpectedly excellent results and proving the non-obviousness and synergistic necessity of the technical solution of the present invention.

[0071] The above embodiments and comparative examples fully illustrate the core innovations, technical advantages, and the basis for establishing the preferred solutions of this invention.

Claims

1. A method for applying a waterproofing slurry foam coating to thin-structure fabrics, characterized in that, Includes the following steps: S1. Prepare a foaming coating slurry, wherein the foaming coating slurry comprises at least an aqueous acrylic emulsion, a masking filler, a compounded foam stabilizer, and a crosslinking agent; wherein the compounded foam stabilizer is a mixture of ammonium stearate emulsion and silicone polyether emulsion; S2. The foamed coating slurry is subjected to mechanical foaming treatment to obtain a foamed slurry; S3. Feed the thin-structure fabric into a coating machine and apply the foaming slurry to one side surface of the thin-structure fabric by a doctor blade coating method. The scraper is disposed on the coating roller and, on the same side along the coating direction, is shifted by a preset distance to the second scraping state relative to the first scraping state in which the foaming slurry can contact and adhere to the surface of the coating roller when leakage occurs during the scraping process. S4. Dry and set the coated thin-structure fabric.

2. The method according to claim 1, characterized in that, The preset distance is 2 to 2.5 cm; and in the second coating state, there is a gap of 0.5 to 1.5 mm between the blade of the scraper and the surface of the coating roller.

3. The method according to claim 1, characterized in that, In the compound foam stabilizer, the mass ratio of ammonium stearate emulsion to silicone polyether emulsion is (85-95):(5-15).

4. The method according to claim 1, characterized in that, Based on the total weight of the foamed coating slurry, the water-based acrylic emulsion has a mass percentage of 60-70%, the masking filler has a mass percentage of 10-15%, the compounded foam stabilizer has a mass percentage of 10-15%, and the crosslinking agent has a mass percentage of 2-3%.

5. The method according to claim 1, characterized in that, In step S2, the foaming ratio of the foaming slurry is controlled to be 3.5 to 3.

7.

6. The method according to claim 1, characterized in that, In step S1, the foamed coating slurry also contains a thickener and a pH adjuster, and the viscosity is controlled at 14000-18000 mPa·s after formulation.

7. The method according to claim 1, characterized in that, Steps S3 and S4 are repeated at least twice to sequentially form a foamed underlayer and a foamed light-blocking layer on the thin-structure fabric.

8. The method according to claim 7, characterized in that, The foam coating slurry that forms the foamed light-shielding layer also contains carbon black slurry, and the foaming ratio of the foaming slurry is 3.1 to 3.

3.

9. The method according to claim 8, characterized in that, After forming the foamed light-shielding layer, a foamed covering layer is applied again, the foaming ratio of which is 3.3 to 3.

5.

10. The method according to claim 9, characterized in that, After applying an anti-stick layer to the surface of the foamed coating, it is dried.

Images