A high-strength-to-weight-ratio and zero-air-permeability nylon umbrella fabric, its preparation method and application

Abstract

The present invention discloses a nylon umbrella cloth with high strength-to-weight ratio and zero air permeability, its preparation method and application. The preparation method includes the following steps: (1) Pretreating the nylon umbrella cloth with polyamidase; (2) Immersing the nylon umbrella cloth treated in step (1) in an acrolein solution to introduce vinyl groups on the fiber surface; (3) Padding the nylon umbrella cloth treated in step (2) in a solution containing isopropylacrylamide, vinyl polyurethane and riboflavin to catalyze the grafting and deposition of polymers on the fabric surface; (4) Calendering the nylon umbrella cloth treated in step (3). Under the conditions of riboflavin initiator and ultraviolet irradiation, isopropylacrylamide and vinyl polyurethane in the present invention undergo graft polymerization and deposition to form polymers on the fabric surface, which not only improves the fabric strength, but also the polyisopropylacrylamide in the polymers has the thermosensitive property of shrinking when heated and expanding when cooled, ensuring that the umbrella cloth has stable zero air permeability in the low-temperature environment of airborne airdrop and high-altitude parachuting.

Description

Technical Field

[0001] The invention relates to the technical field of textile dyeing and finishing, and in particular to a brocade umbrella cloth with high strength-to-weight ratio and zero air permeability, and a preparation method and application thereof. Background Art

[0002] Polyamide fiber (commonly known as nylon) has high strength, high wear resistance and excellent elasticity. It is a synthetic fiber raw material with ideal mechanical properties. It can be used not only in sportswear and outdoor textile processing, but also in industrial textiles and special textile processing. Nylon spunlace, which is made of nylon filament and woven with plain weave, is a common nylon fabric, which can be used in a variety of special textiles including parachute cloth.

[0003] The canopy used for parachutes needs to have the application characteristics of high strength, lightness, and controllable air permeability. The existing brocade canopy fabrics are mostly made of nylon 66 high-strength yarn as raw material, woven with a plain weave structure, refined and degreased, and then processed with coating. In recent years, canopy fabrics with high strength-to-weight ratio and low air permeability (even zero air permeability) have become a research difficulty in the special textile industry. The processing methods of this type of special textiles are mainly concentrated in two aspects. On the one hand, by selecting fine denier nylon 66 filaments as raw materials and combining high warp and weft density for weaving, the high strength-to-weight ratio requirements are met. On the other hand, polypropylene ester finishing agents are used for coating processing to meet the requirements of low or even zero air permeability. In actual production, nylon silk products with high strength-to-weight ratio and zero air permeability are often difficult to achieve mass production. The reason is that if they are not coated, although the strength-to-weight ratio can reach a high value, it cannot meet the requirements of low air permeability; on the contrary, after coating, the air permeability can be reduced, but the weight of the umbrella canopy fabric increases significantly, which often cannot meet the requirements of high strength-to-weight ratio. In addition, the durability of the umbrella canopy surface coating is also a technical problem that needs to be solved urgently. The main reason is that the number of reactive groups (such as hydroxyl groups, amino groups, etc.) in nylon fibers is far less than that of natural fibers. The formed high-molecular polymer coating can only be combined with the fiber through hydrogen bonds and van der Waals forces, and the finishing effect is not durable enough.

[0004] Therefore, how to reasonably construct the processing technology of brocade umbrella cloth with high strength-to-weight ratio and zero air permeability, and achieve the quality requirements of umbrella cloth products with high strength-to-weight ratio and zero air permeability under the conditions of less coating finishing agent usage and lower production energy consumption, is a technical problem that needs to be urgently solved in the processing of brocade umbrella canopy in the current umbrella system. Summary of the invention

[0005] In view of the above problems, the present invention provides a brocade umbrella cloth with high strength-to-weight ratio and zero air permeability, and a preparation method and application thereof, aiming to achieve coating finishing of the brocade umbrella cloth with high strength-to-weight ratio and zero air permeability under relatively mild conditions, improve the durability of the finishing effect, and achieve the purpose of improving the finishing effect.

[0006] To achieve the above object, on the one hand, the present invention provides a preparation method of a high-strength-to-weight-ratio and zero-air-permeability nylon silk umbrella cloth, and the preparation method includes the following steps:

[0007] (1) Pretreat the nylon silk umbrella cloth with polyamidase, and wash the sample after treatment.

[0008] (2) Immerse the nylon silk umbrella cloth treated in step (1) in an acrolein solution, introduce vinyl on the fiber surface through a Schiff base reaction, and wash the sample after treatment.

[0009] (3) Pad the nylon silk umbrella cloth treated in step (2) in a solution of isopropylacrylamide, vinyl polyurethane and riboflavin, and catalyze graft deposition of polymers on the fabric surface through ultraviolet irradiation, and dry the sample after treatment.

[0010] (4) Calender the nylon silk umbrella cloth treated in step (3).

[0011] The present invention first pre-treats the nylon silk umbrella cloth enzymatically with polyamidase to hydrolyze the amide bonds on the surface of nylon fibers to generate amino groups, obtaining a nylon silk umbrella cloth with reactive activity; then, introduce vinyl on the nylon silk surface through reaction with acrolein, and then pad the nylon silk umbrella cloth in a mixed solution containing isopropylacrylamide, vinyl polyurethane and riboflavin, and carry out catalytic graft polymerization crosslinking through ultraviolet irradiation; finally, obtain a high-strength-to-weight-ratio and zero-air-permeability nylon silk umbrella cloth after calendering finishing.

[0012] The nylon silk umbrella cloth prepared by the above method

[0013] Preferably, in step (1), the nylon silk umbrella cloth is woven with nylon 66 filaments as raw materials using a plain weave, and the gram weight per square meter is 36 - 40 g / m 2 of the umbrella cloth.

[0014] Preferably, in step (1), the pretreatment method is: treat under the conditions of a polyamidase concentration of 0.5 - 1.5 U / mL, pH 7 - 8, temperature 45 - 55°C, and bath ratio 1:(5 - 10) for 0.5 - 1 hour.

[0015] Preferably, in step (2), the concentration of the acrolein solution is 5 - 10 g / L, and the reaction conditions are: react under the conditions of temperature 20 - 40°C, pH 4 - 6, and bath ratio 1:(5 - 10) for 1 - 2 hours.

[0016] Preferably, in step (3), the concentration of isopropylacrylamide in the solution is 10 - 20 g / L, the concentration of vinyl polyurethane is 30 - 50 g / L, and the concentration of riboflavin is 1 - 2.5 g / L.

[0017] Preferably, in step (3), the vinyl polyurethane includes polyester-based aqueous polyurethane containing vinyl or polyether-based aqueous polyurethane containing vinyl.

[0018] Preferably, in step (3), the padding conditions are a liquor pickup of 80-100%; and / or

[0019] the ultraviolet light irradiation conditions are as follows: the irradiation intensity of the light source is 20-50 mW / cm 2 , and the irradiation time is 15-20 min.

[0020] Preferably, in step (4), the calendering treatment conditions are: the calender roll temperature is 150-180 °C, the pressure is 120-160 kPa, and the vehicle speed is 20-40 m / min.

[0021] The second aspect of the present invention provides a high-strength-to-weight-ratio and zero air permeability nylon silk umbrella cloth prepared by the above preparation method.

[0022] The third aspect of the present invention provides the application of the above nylon silk umbrella cloth in the preparation of a parachute.

[0023] Through the above technical solutions, the present invention achieves the following beneficial effects:

[0024] The present invention first uses polyamidase for enzymatic pretreatment of nylon silk umbrella cloth to hydrolyze the amide bonds on the surface of nylon fibers to generate amino groups, obtaining nylon silk umbrella cloth with reactive activity; then, vinyl groups are introduced onto the nylon silk surface by reacting with acrolein, and then the nylon silk umbrella cloth is padded with a mixed solution containing isopropylacrylamide, vinyl polyurethane, and riboflavin, and catalytic graft polymerization crosslinking occurs under ultraviolet light irradiation; finally, after calendering finishing, a high-strength-to-weight-ratio and zero air permeability nylon silk umbrella cloth is obtained. Compared with the finishing based on the traditional direct coating and baking method, the present invention has the following advantages:

[0025] (1) The high strength-to-weight ratio and zero air permeability effects are remarkable: The present invention constructs a method for realizing the high strength-to-weight ratio and zero air permeability of nylon silk umbrella cloth. Among them, under the conditions of riboflavin initiator and ultraviolet irradiation, isopropylacrylamide and vinyl polyurethane undergo graft polymerization deposition to form polymers on the fabric surface, which not only improves the fabric strength, but also polyisopropylacrylamide in the polymer has the thermosensitive property of shrinking when heated and expanding when cooled, ensuring that the umbrella cloth has a stable zero air permeability in the low-temperature environment of airborne airdrop and high-altitude parachuting.

[0026] (2) The finishing effect is lasting: There are relatively few reactive groups on the surface of nylon fibers, and after common coating finishing, the film forming fastness is poor or the binding is not firm. In the method described in the present invention, more vinyl sites are introduced through fiber surface modification, realizing polymer deposition based on graft polymerization, and endowing the nylon silk umbrella cloth surface with a more lasting and stable finishing effect.

[0027] (3) Low production energy consumption: By using the method described in the present invention, the catalytic graft polymerization crosslinking of nylon umbrella cloth can be realized under low temperature and relatively mild conditions. Not only are the reaction conditions milder during the production process, but also the problem that the traditional high-temperature baking finishing method easily causes a decrease in fabric strength is avoided. Detailed implementation manners

[0028] The following further elaborates on the detailed implementation manners of the present invention in conjunction with examples. It should be understood that the detailed implementation manners described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0029] Example 1:

[0030] (1) Polyamidase pretreatment: Pretreat the nylon umbrella cloth with polyamidase, and wash the sample after treatment; among them, the polyamidase is 0.5 U / mL, and it is treated for 0.5 hours under the conditions of pH 7, 45 °C and bath ratio 1:5; the nylon umbrella cloth is made of nylon 66 filaments as raw materials, woven with plain weave, and the gram weight per square meter is 36 g / m 2 of umbrella cloth;

[0031] (2) Introduction of vinyl groups on the nylon surface: Immerse the nylon umbrella cloth treated in step (1) in an acrolein solution with a concentration of 5 g / L, and treat it for 1 hour under the conditions of 20 °C, pH 4 and bath ratio 1:5. Introduce vinyl groups on the fiber surface through Schiff base reaction, and wash the sample after treatment;

[0032] (3) Catalytic graft deposition of polymer: Immerse the nylon umbrella cloth treated in step (2) in a solution containing 10 g / L of isopropylacrylamide, 30 g / L of vinyl-containing polyester-based waterborne polyurethane and 1 g / L of riboflavin, with a liquor pickup rate of 80%. Irradiate with an ultraviolet light source with an intensity of 20 mW / cm 2 for 15 min, and catalytically graft deposit the polymer on the fabric surface through ultraviolet light irradiation. After treatment, the sample is dried at 105 °C;

[0033] (4) Calendering post-treatment: Calender the nylon umbrella cloth treated in step (3) under the conditions of a temperature of 150 °C, a calendering pressure of 120 kPa, and a vehicle speed of 20 m / min.

[0034] Example 2:

[0035] (1) Polyamidase pretreatment: Pretreat the nylon umbrella cloth with polyamidase, and wash the sample after treatment; among them, the polyamidase is 1.5 U / mL, and it is treated for 1 hour under the conditions of pH 8, 55 °C and bath ratio 1:10; the nylon umbrella cloth is woven with plain weave of nylon 66 filaments and has a gram weight per square meter of 40 g / m 2 of umbrella cloth;

[0036] (2) Introduction of vinyl groups onto the surface of nylon silk: Immerse the nylon silk umbrella cloth treated in step (1) in an acrolein solution with a concentration of 10 g / L, and treat it for 2 hours at 40°C, pH 6, and a liquor ratio of 1:10. Introduce vinyl groups onto the fiber surface through the Schiff base reaction, and then thoroughly wash the sample after treatment.

[0037] (3) Catalytic grafting and deposition of polymers: Immerse and pad the nylon silk umbrella cloth treated in step (2) in a solution containing 20 g / L of isopropylacrylamide, 50 g / L of vinyl-containing polyether-based waterborne polyurethane, and 2.5 g / L of riboflavin, with a pick-up rate of 100%. Irradiate it with an ultraviolet light source with an intensity of 50 mW / cm 2 for 20 min to catalytically graft and deposit polymers on the fabric surface through ultraviolet light irradiation, and then dry the sample after treatment.

[0038] (4) Calendering post-treatment: Perform calendering treatment on the nylon silk umbrella cloth treated in step (3) under the conditions of a calender roll temperature of 180°C, a calendering pressure of 160 kPa, and a vehicle speed of 40 m / min.

[0039] Example 3:

[0040] (1) Pretreatment with polyamidase: Pretreat the nylon silk umbrella cloth with polyamidase, and then thoroughly wash the sample after treatment. Among them, the polyamidase is 1 U / mL, and it is treated for 1 hour at pH 7.5, 50°C, and a liquor ratio of 1:8; the nylon silk umbrella cloth is woven with nylon 66 filament plain weave and has a weight per square meter of 38 g / m 2 of umbrella cloth;

[0041] (2) Introduction of vinyl groups onto the surface of nylon silk: Immerse the nylon silk umbrella cloth treated in step (1) in an acrolein solution with a concentration of 8 g / L, and treat it for 1.5 hours at 30°C, pH 5, and a liquor ratio of 1:8. Introduce vinyl groups onto the fiber surface through the Schiff base reaction, and then thoroughly wash the sample after treatment.

[0042] (3) Catalytic grafting and deposition of polymers: Immerse and pad the nylon silk umbrella cloth treated in step (2) in a solution containing 15 g / L of isopropylacrylamide, 40 g / L of vinyl-containing polyether-based waterborne polyurethane, and 2 g / L of riboflavin, with a pick-up rate of 90%. Irradiate it with an ultraviolet light source with an intensity of 40 mW / cm 2 for 16 min to catalytically graft and deposit polymers on the fabric surface through ultraviolet light irradiation, and then dry the sample after treatment.

[0043] (4) Calendering post-treatment: Perform calendering treatment on the nylon silk umbrella cloth treated in step (3) under the conditions of a calender roll temperature of 160°C, a calendering pressure of 140 kPa, and a vehicle speed of 30 m / min.

[0044] Comparative Example 1:

[0045] The nylon umbrella cloth in Example 1 without any treatment.

[0046] Comparative Example 2:

[0047] In Example 1, without undergoing treatments (1), (2), and (4), only undergoing step (3), with other conditions or descriptions being the same as in Example 1.

[0048] Comparative Example 3:

[0049] In Example 1, without undergoing treatments (2) and (4), only undergoing steps (1) and (3), with other conditions or descriptions being the same as in Example 1.

[0050] Comparative Example 4:

[0051] In Example 1, without undergoing treatments (1) and (4), only undergoing steps (2) and (3), with other conditions or descriptions being the same as in Example 1;

[0052] Comparative Example 5:

[0053] In Example 1, without undergoing treatment (4), only undergoing steps (1), (2), and (3), with other conditions or descriptions being the same as in Example 1;

[0054] Comparative Example 6:

[0055] The nylon umbrella cloth in Example 2 without any treatment.

[0056] Comparative Example 7:

[0057] In Example 2, without undergoing treatments (1), (2), and (4), only undergoing step (3), with other conditions or descriptions being the same as in Example 2.

[0058] Comparative Example 8:

[0059] In Example 2, without undergoing treatments (2) and (4), only undergoing steps (1) and (3), with other conditions or descriptions being the same as in Example 2.

[0060] Comparative Example 9:

[0061] In Example 2, without undergoing treatments (1) and (4), only undergoing steps (2) and (3), with other conditions or descriptions being the same as in Example 2;

[0062] Comparative Example 10:

[0063] In Example 2, without undergoing treatment (4), only undergoing steps (1), (2), and (3), with other conditions or descriptions being the same as in Example 2.

[0064] Performance Test

[0065] Measure the gram weight per square meter, breaking strength, and air permeability of the specimens in Examples 1-3 and Comparative Examples 1-10 above, and calculate the strength-to-weight ratio of the specimens (i.e., strength / gram weight per square meter); wash the specimens of Examples 1-3 and Comparative Examples at 60 °C for 2 hours and then dry them at room temperature again, and measure the air permeability of the nylon umbrella cloth after washing. Among them, the gram weight per square meter of the nylon umbrella cloth is measured with reference to FZ / T 65001-1995 / 5.6 "Textiles for special industrial use - Test methods for physical and mechanical properties - Weight per square meter"; the warp breaking strength of the umbrella cloth is measured with reference to FZ / T 65001-1995 / 5.4 "Textiles for special industrial use - Test methods for physical and mechanical properties - Breaking strength and elongation"; the air permeability is measured with reference to FZ / T 65001-1995 / 5.8 "Textiles for special industrial use - Test methods for physical and mechanical properties - Air permeability". The measurement results are shown in Table 1.

[0066] Table 1 Performance test results

[0067]

[0068] As can be seen from Table 1:

[0069] a. The specimens (Example 1, Example 2, Example 3) treated by the method described in the present invention have a relatively high strength-to-weight ratio, and the air permeability of the fabric specimens before and after washing is 0, indicating that the method described in the present invention can promote the catalytic grafting and cross-linking of polymers on the fiber surface, and further improve the flatness of the fabric by calendering, enhance the structural compactness of the fabric, reduce the air permeability, meet the preparation requirements of high-strength-to-weight ratio and zero air permeability nylon umbrella cloth, and the finishing effect has lasting stability.

[0070] b. The air permeability of the fabric specimens of the nylon umbrella cloth specimens (Comparative Example 1, Comparative Example 6) without any treatment is the highest, which cannot meet the application requirements of special spinning materials such as parachutes.

[0071] c. For the specimens (Comparative Example 2, Comparative Example 7) that are not treated by (1), (2), and (4) and are only treated by step (3), the gram weight and breaking strength of the fabric are both increased compared with the untreated specimens, but the strength-to-weight ratio is lower than that of the corresponding example specimens, and the air permeability of the specimens after washing increases significantly, indicating that the polymer formed by catalytic polymerization and cross-linking on the specimen surface is not firmly combined with the fiber, and the finishing effect does not have persistence.

[0072] d. For the specimens that are not processed through (2) and (4) but only through steps (1) and (3) (Comparative Example 3 and Comparative Example 8), although the nylon fibers are pretreated with polyamidase to generate amino groups in step (1), since the vinyl sites are not introduced through step (2) treatment, the fibers do not graft and crosslink with the polymer in step (3) treatment. Therefore, the strength of the specimens slightly decreases compared to the specimens only processed through step (3), and the air permeability of the specimens increases after washing, indicating that the finishing effect is not durable.

[0073] e. For the specimens that are not processed through (1) and (4) but only through steps (2) and (3) (Comparative Example 4 and Comparative Example 9), the strength is lower than that of the corresponding examples. Since the vinyl aldehyde in step (2) fails to react with the amino groups on the fiber surface, the actual improvement in the reaction activity on the fiber surface is less, and the covalent bond binding between the polymer and the fiber cannot be achieved. The wash resistance of the polymer on the fiber surface after finishing is also insufficient, manifested as an increase in air permeability after washing.

[0074] f. The specimens only processed through steps (1), (2), and (3) (Comparative Example 5 and Comparative Example 10) have a high strength-to-weight ratio similar to that of the examples, indicating that after pretreatment with polyamidase, the number of amino groups on the fiber surface can be increased, promoting the binding of vinyl aldehyde to the fiber through Schiff base reaction, thereby introducing more vinyl reaction sites on the surface of nylon fibers and promoting the subsequent free radical catalytic graft crosslinking of isopropylacrylamide and vinyl polyurethane through ultraviolet light initiation, forming a polymer with a relatively high binding fastness. Therefore, the umbrella cloth has a high strength-to-weight ratio. On the other hand, due to the lack of calendering treatment, there are a small number of intermittences on the surface of the nylon umbrella cloth, so it still shows a relatively low air permeability. However, the air permeability of the specimens after washing is similar to that before washing, indicating that the polymer on the surface has a good binding fastness on the umbrella cloth.

[0075] The preferred embodiments of the present invention are described in detail with the accompanying drawings of the above embodiments. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0076] In addition, it should be noted that for the various specific technical features described in the above specific embodiments, they can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0077] Furthermore, any combination can be made between different embodiments of the present invention as long as it does not violate the idea of the present invention, and it should also be regarded as the content disclosed by the present invention.

Claims

1. A preparation method of a brocade silk umbrella cloth with high strength-to-weight ratio and zero air permeability, characterized in that, It includes the following steps: (1) Pretreat the nylon umbrella cloth with polyamidase; (2) Immerse the nylon umbrella cloth treated in step (1) in an acrolein solution, and introduce vinyl on the fiber surface through a Schiff base reaction. The conditions for the reaction are: react for 1 to 2 hours under the conditions of a temperature of 20 to 40 °C, a pH of 4 to 6, and a bath ratio of 1:(5 to 10); (3) Immerse the nylon umbrella cloth treated in step (2) in a solution containing isopropylacrylamide, vinyl polyurethane and riboflavin, and catalyze the graft deposition of polymers on the fabric surface through ultraviolet irradiation. After treatment, dry the sample. The conditions of the ultraviolet irradiation are: the irradiation intensity of the light source is 20-50 mW / cm 2 , and the irradiation time is 15-20 min; (4) Calender the nylon umbrella cloth treated in step (3).

2. The preparation method according to claim 1, wherein In step (1), the nylon umbrella cloth is woven with nylon 66 filament as the raw material using a plain weave, and the gram weight per square meter is 36-40 g / m 2 umbrella cloth.

3. The preparation method according to claim 1, characterized in that, In step (1), the pretreatment method is: treat for 0.5 to 1 hour under the conditions of a polyamidase concentration of 0.5 to 1.5 U / mL, a pH of 7 to 8, a temperature of 45 to 55 °C, and a bath ratio of 1:(5 to 10).

4. The preparation method according to claim 1, characterized in that, In step (2), the concentration of the acrolein solution is 5 to 10 g / L.

5. The preparation method according to claim 1, characterized in that, In step (3), the concentration of the isopropylacrylamide in the solution is 10 to 20 g / L, the concentration of the vinyl polyurethane is 30 to 50 g / L, and the concentration of the riboflavin is 1 to 2.5 g / L.

6. The preparation method according to claim 1, wherein, In step (3), the vinyl polyurethane includes a polyester-based aqueous polyurethane containing vinyl or a polyether-based aqueous polyurethane containing vinyl.

7. The preparation method according to claim 1, characterized in that, In step (3), the padding conditions are a liquor pickup rate of 80 to 100%.

8. The preparation method according to any one of claims 1 to 7, characterized in that, In step (4), the calendering treatment conditions are: a calender roll temperature of 150 to 180 °C, a pressure of 120 to 160 kPa, and a vehicle speed of 20 to 40 m / min.

9. The nylon umbrella cloth with high strength-to-weight ratio and zero air permeability prepared by the preparation method according to any one of claims 1 to 8.

10. The application of the nylon umbrella cloth according to claim 9 in the preparation of a parachute.

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