High-strength light-weight impregnated canvas and preparation method thereof

Abstract

The invention provides high-strength light-weight impregnated canvas and a preparation method thereof.The impregnated canvas comprises gray fabric, a first impregnation layer arranged on the gray fabric and a second impregnation layer arranged on the first impregnation layer, the gray fabric is formed by weaving warp yarn and weft yarn, the warp yarn comprises main warp yarn and binding warp yarn, and the binding warp yarn comprises weft yarn and main warp yarn; the main warp yarns and the weft yarns are interwoven and bundled together through the bundling warp yarns, the main warp yarns are special cords formed by secondarily twisting a plurality of strands of primarily twisted cords, and the primarily twisted cords comprise inner core fibers and outer layer fibers wrapping the peripheries of the inner core fibers. High-strength, high-lubricity and difficult-to-adhere fibers serve as inner core fibers, high-strength and easy-to-adhere fibers serve as outer layer fibers, the high-strength characteristic of a novel fiber material is effectively exerted through the mixed weaving design that the inner core fibers wrap the fibers, and the problem of interface adhesion with rubber is effectively solved through the physical effect with other fibers; the application range of various high-performance fiber materials is greatly expanded.

Description

Technical Field

[0001] The invention relates to the technical field of rubber conveyor belts for industrial conveying, in particular to a high-strength and lightweight dipped canvas and a preparation method thereof. Background Art

[0002] Rubber conveyor belts have been widely used to transport various industrial bulk materials, such as raw coal, iron ore and other ores. At present, rubber conveyor belts with steel rope cores are mainly used for long distances. However, steel rope conveyor belts are heavy and consume a lot of energy during operation. At the same time, they are easy to tear, have poor impact resistance, and are prone to rust, which brings certain risks to the safe operation of conveyor belts. Therefore, it is of great significance to use high-performance synthetic fibers to replace steel ropes and develop new high-strength, lightweight, stable and reliable conveyor belt products.

[0003] In recent years, the use of fiber fabrics as skeleton materials to replace traditional steel wire rope conveyor belts has gradually attracted market attention, especially aramid fiber, which has the advantages of high strength, high modulus, impact resistance, flame retardancy, and light weight. The conveyor belts developed with it as a skeleton material are widely used in the industry and have great advantages in lightweight and energy saving. Under the same linear density, the strength of aramid fiber is 6 times that of steel wire rope, but the price is 10 times that of steel wire rope. The strength-price ratio of aramid is 0.6 times that of steel wire rope. Steel wire rope is cheaper than aramid, and there is a certain resistance to the promotion of aramid conveyor belts. In addition, there are risks of internal wear and tear during use. Therefore, the development of lightweight conveyor belts with more stable and excellent performance and higher cost performance has broad market demand and promotion value.

[0004] In addition to aramid fibers, ultra-high molecular weight polyethylene fibers, polyarylate fibers, polyimide fibers, poly(p-phenylene benzobisoxazole) fibers, polyvinyl acetal fibers, etc., also have excellent performance or high cost-effectiveness, and are feasible for use in the field of conveyor belt skeleton materials. For example, ultra-high molecular weight polyethylene fibers are 9 times stronger than steel wire ropes, 2 / 3 more dense than aramid fibers, and are priced lower than aramid fibers. However, in the application process, problems such as interface adhesion, internal wear, and a serious decrease in overall strength due to uneven modulus between different fibers have affected the application and promotion of some fiber materials. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a high-strength and lightweight dipped canvas and a preparation method thereof, which effectively solve the problems of interface adhesion, internal wear and other problems existing in the use of some fiber materials; the canvas is woven from main warp yarns, binding warp yarns and weft yarns, the main warp yarns are special cords twisted with a variety of fibers, and the special cords are made of multiple strands of primary twisted cords twisted together; the primary twisted cords are composed of ultra-high molecular weight polyethylene fibers or polyarylate fibers at the center as inner core fibers, and the outer layer fibers that increase the tensile strength and enhance the interface adhesion are wrapped in parallel or in a spiral winding manner by twisting; the design of the inner core fibers covering the outer layer fibers is adopted, the outer layer fibers are bonded to the rubber material, and the force is transferred to the inner core fibers through physical action, which effectively solves the industry bottleneck problems that have not been solved, such as poor interface adhesion of materials such as ultra-high molecular weight polyethylene, and the surface adhesion problems caused by surface treatment of some fiber materials with oil agents considering smooth and wear-resistant surfaces.

[0006] The technical solution adopted by the present invention is: A high-strength and lightweight dipped canvas, wherein: the dipped canvas comprises a grey cloth, a first impregnation layer arranged on the grey cloth, and a second impregnation layer arranged on the first impregnation layer, the grey cloth is woven from warp yarns and weft yarns, the warp yarns comprise main warp yarns and binding warp yarns, the main warp yarns are interwoven with the weft yarns and bundled together by binding warp yarns, the main warp yarns are special cords made by twisting multiple strands of primary twisted ropes, the primary twisted ropes comprise inner core fibers and outer layer fibers wrapped around the inner core fibers.

[0007] Preferably, the high-strength and lightweight dipped canvas, wherein: the bundling warp yarn is selected from one or more of nylon 66, nylon 6, polyvinyl alcohol acetal fiber, and polyester fiber, and the fineness is 550 to 4000 dtex; the bundling warp yarn is a twisted yarn obtained by twisting 1 to 5 strands of bundling warp yarn.

[0008] Preferably, the high-strength and lightweight dipped canvas, wherein: the weft yarn is selected from one or more of nylon 66, nylon 6, polyvinyl alcohol acetal fiber, polyester fiber, and has a fineness of 550 to 4000 dtex; the weft yarn is a twisted yarn obtained by twisting 1 to 12 strands of weft yarn.

[0009] Preferably, in the high-strength and lightweight dipped canvas, the inner core fiber is selected from one of ultra-high molecular weight polyethylene fiber and polyarylate fiber.

[0010] Preferably, in the high-strength and lightweight dipped canvas, the molecular weight of the ultra-high molecular weight polyethylene fiber is greater than 1 million.

[0011] Preferably, the high-strength and lightweight dipped canvas, wherein: the outer layer fiber is selected from one or more of polyarylate fiber, polyarylamide fiber, polyimide fiber, poly(p-phenylene benzobisoxazole) fiber and polyvinyl acetal fiber.

[0012] Preferably, in the high-strength and lightweight dipped canvas, the outer layer fibers are wrapped around the periphery of the inner core fibers in parallel and side by side or in a spiral winding manner by twisting.

[0013] Preferably, the high-strength and lightweight dipped canvas, wherein: the breaking elongation of the special cord is 2% to 6%, and the fineness is 500dtex to 6000dtex.

[0014] The present invention also provides a method for preparing a high-strength and lightweight dipped canvas, comprising the following steps: Step S1. Weaving the main warp yarn, the binding warp yarn and the weft yarn to form a grey cloth; Step S2. Add the grey cloth obtained in step S1 into the first bath impregnation liquid for impregnation treatment, and dry at 100-120° C. for 20-50 min to obtain a semi-finished product; Step S3. Add the semi-finished product obtained in step S2 into the second bath dipping solution for dipping treatment, and dry it at 110-140° C. for 30-100 min to obtain a high-strength and lightweight dipped canvas.

[0015] Preferably, the preparation method of the high-strength lightweight dipped canvas is as follows: the first bath dipping solution includes, by mass percentage, 1% to 5% water-soluble epoxy resin, 0 to 2% blocked isocyanate, 0 to 2% water-based curing agent, and the rest is deionized water, the above total being 100%; the second bath dipping solution includes latex and water-based adhesive, and the solid ratio of latex to water-based adhesive is 85:15 to 60:40; the latex is selected from one or more of butyl latex, natural latex, styrene butadiene latex, carboxylated styrene butadiene, and carboxylated nitrile latex; the water-based adhesive is a phenolic resin aqueous solution or a mixed aqueous solution of a water-soluble epoxy resin and a curing agent, and the curing agent is a blocked isocyanate or a water-based imidazole curing agent.

[0016] Advantages of the present invention: (1) The high-strength and lightweight dipped rubber canvas and its preparation method of the present invention use high-strength, high-lubricity, and difficult-to-bond fibers as inner core fibers and high-strength and easy-to-bond fibers as outer layer fibers. Through the mixed design of inner core fibers and sheathed fibers, the high-strength characteristics of the new fiber material are effectively brought into play. Through the physical effect with other fibers, the interface bonding problem with rubber is effectively solved, which greatly improves the application range of various high-performance fiber materials.

[0017] (2) The high-strength and lightweight dipped canvas and its preparation method of the present invention, the design of inner core fiber covering outer layer fiber, can effectively bring out the advantages of the two fibers, make up for the performance deficiencies of a single fiber in certain aspects, and effectively improve the problem of internal wear caused by high friction coefficient that may exist in similar fibers under stress.

[0018] (3) The high-strength and lightweight dipped canvas and its preparation method of the present invention develop and design a new skeleton material that is lightweight, high-strength, low-elongation, impact-resistant and tear-resistant based on new materials, providing a fiber fabric for conveyor belts with better performance and higher cost performance; some of the fiber materials involved have not yet been used in the field of conveyor belts, and the implementation of this technology will greatly promote the application scope of some fiber materials; (4) Compared with the traditional high-temperature dipping process, the high-strength and lightweight dipped canvas and its preparation method of the present invention provide a relatively low-temperature dipping process, which provides an effective surface treatment solution for some fiber materials that are not resistant to high temperatures, and has certain advantages in energy saving and consumption reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a three-dimensional schematic diagram of the fabric structure of the present invention.

[0020] Figure 2 It is a fabric structure diagram of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with specific drawings and embodiments.

[0022] The high-strength and lightweight dipped canvas of the present invention is woven into a canvas with a complex fabric structure by wrapping the outer layer of fibers, which has the functions of increasing tensile strength and enhancing interface adhesion, in parallel or in a twisted and spirally wound manner around the periphery of the inner core fibers; a three-dimensional schematic diagram of the complex fabric structure is shown in the attached figure. Figure 1 As shown in the attached diagram, the fabric structure is Figure 2 As shown, the high-strength and lightweight dipped canvas adopts a diameter straight weft design, which effectively exerts the mechanical strength of the main warp yarn and effectively solves the problem of significant decrease in overall strength caused by asynchronous force due to slight differences in the curl of different yarns in other structures.

[0023] Example 1 like Figure 1-Figure 2A high-strength and lightweight dipped canvas, the dipped canvas comprises a grey cloth, a first impregnation layer arranged on the grey cloth and a second impregnation layer arranged on the first impregnation layer, the grey cloth is woven from warp yarns and weft yarns 1, the warp yarns comprise main warp yarns 2 and binding warp yarns 3, the main warp yarns 2 are interwoven with the weft yarns 1 and are bundled together through the binding warp yarns 3, the main warp yarns are twisted together to form a special cord by twisting a plurality of primary twisted cords, the primary twisted cords comprise inner core fibers and outer layer fibers wrapped around the outer core fibers, the outer layer fibers serve to improve tensile strength and enhance interface bonding; the outer layer fibers are wrapped around the outer core fibers in parallel and side by side.

[0024] The inner core fiber is 50% polyarylate fiber, the outer layer fiber is 50% polyarylamide fiber, the breaking elongation of the special rope is between 2% and 6%, the fineness is between 3000dtex and 4000dtex, the yarn of the binding warp yarn is polyester fiber, the fineness is 2000 to 3000 dtex, and the binding warp yarn is a twisted yarn that uses 3-ply binding warp yarns to be twisted together; the weft yarn is nylon 66, and the weft yarn is a twisted yarn that uses 6-ply weft yarns to be twisted together.

[0025] The method for preparing the high-strength and lightweight dipped canvas of this embodiment comprises the following steps: Step S1. Weaving the main warp yarn 2, the binding warp yarn 3 and the weft yarn 1 to form a grey cloth; Step S2. Add the grey cloth to the first bath impregnation liquid for impregnation treatment, wherein the first bath impregnation liquid includes 1% water-soluble epoxy resin, 1% blocked isocyanate, and the rest is deionized water, the total of which is 100%, and dry at 120° C. for 40 min to obtain a semi-finished product; the water-soluble epoxy resin is propylene glycol triglycidyl ether, and the manufacturer of the blocked isocyanate is Covestro Polymer China Co., Ltd., with a brand number of 2794; Step S3: adding the semi-finished product into the second bath dipping solution for dipping treatment, and drying at 140° C. for 90 min to obtain a high-strength and lightweight dipped canvas.

[0026] The second bath dipping solution includes latex and water-based adhesive, the solid ratio of latex to water-based adhesive is 85:15, the solid content of the aqueous solution after the latex and water-based adhesive are mixed is 20%, and the latex is butadiene latex; the water-based adhesive is a mixed aqueous solution of 2-ethyl-4-methylimidazole and epoxy resin, the water-based adhesive includes water-soluble epoxy resin and 2-ethyl-4-methylimidazole, the mass ratio of water-soluble epoxy resin to 2-ethyl-4-methylimidazole is 5:1, and the water-soluble epoxy resin is propylene glycol triglycidyl ether.

[0027] The design strength of Example 1 is 3150 N / mm, the actual strength is 3280 N / mm, the bonding performance is tested according to GB / T 6759 N / mm, and the bonding strength is 20.3.

[0028] Example 2 The difference between Example 2 and Example 1 is that the inner core fiber is 80% ultra-high molecular weight polyethylene, the outer layer fiber is 20% polyimide fiber, the yarn for binding the warp yarn is nylon 66, and the weft yarn is nylon 6.

[0029] In step S2, the first bath immersion liquid includes 1% water-soluble epoxy resin and 2% blocked isocyanate, the immersion treatment temperature is 110°C, and the reaction time is 40 minutes; in step S3, the latex is butylpyrrolidone latex; the immersion treatment temperature is 140°C, and the reaction time is 90 minutes.

[0030] The design strength of Example 2 is 2000 N / mm, the actual strength is 2180 N / mm, the bonding performance is tested according to GB / T 6759 N / mm, and the bonding strength is 17.8.

[0031] Example 3 The difference between Example 3 and Example 1 is that the inner core fiber is 10% polyarylate, the outer layer fiber is 90% polyvinyl acetal fiber, the yarn for binding the warp yarn is polyester fiber, and the weft yarn is nylon 66.

[0032] In step S2, the first bath immersion liquid includes 5% water-soluble epoxy resin, the immersion treatment temperature is 120° C., and the reaction time is 40 minutes; in step S3, the latex is butylpyrrolidone latex; the immersion treatment temperature is 140° C., and the reaction time is 90 minutes.

[0033] The design strength of Example 3 is 1000 N / mm, the actual strength is 1120 N / mm, the bonding performance is tested according to GB / T 6759 N / mm, and the bonding strength is 18.8.

[0034] Example 4 The difference between Example 4 and Example 1 is that the inner core fiber is 35% ultra-high molecular weight polyethylene, the outer layer fiber is 65% polyaramid fiber, the yarn for binding the warp yarn is polyester fiber, and the weft yarn is nylon 66.

[0035] In step S2, the first bath immersion liquid includes 2% water-soluble epoxy resin and 2% blocked isocyanate, the immersion treatment temperature is 120°C, and the reaction time is 30 minutes; in step S3, the latex is butylpyrrolidone latex; the immersion treatment temperature is 130°C, and the reaction time is 80 minutes.

[0036] The design strength of Example 4 is 2500 N / mm, the actual strength is 2840 N / mm, the bonding performance is tested according to GB / T 6759 N / mm, and the bonding strength is 18.2.

[0037] Example 5 The difference between Example 5 and Example 1 is that the inner core fiber is 50% ultra-high molecular weight polyethylene, the outer layer fiber is 50% polyvinyl acetal fiber, the yarn binding the warp yarn is polyvinyl acetal fiber, and the weft yarn is polyester fiber.

[0038] In step S2, the first bath immersion liquid includes 2% water-soluble epoxy resin and 3% blocked isocyanate, the immersion treatment temperature is 120°C, and the reaction time is 30 minutes; in step S3, the latex is butyl pyrrolidone latex / styrene butadiene latex; the immersion treatment temperature is 130°C, and the reaction time is 80 minutes.

[0039] The design strength of Example 5 is 1600 N / mm, the actual strength is 1820 N / mm, and the bonding performance is tested according to GB / T 6759, and the bonding strength is 19.4 N / mm.

[0040] Comparative Example 1 The difference between Comparative Example 1 and Example 4 is that the inner core fiber is 50% ultra-high molecular weight polyethylene, and the outer layer fiber is 50% ultra-high molecular weight polyethylene.

[0041] The design strength of comparative example 1 is 2500 N / mm, the actual strength cannot be tested, and the bonding performance is tested according to GB / T 6759 N / mm, and the bonding strength is 3.2.

[0042] In Comparative Example 1, both the inner core fiber and the outer layer fiber are ultra-high molecular weight polyethylene. Since there is no coating structure in Comparative Example 1, the strength cannot be tested and the bonding performance is very poor.

[0043] Comparative Example 2 The difference between Comparative Example 2 and Example 5 is that the temperature of the immersion treatment in step S2 is 90° C. and the reaction time is 30 min; the temperature of the immersion treatment in step S3 is 100° C. and the reaction time is 80 min.

[0044] The design strength of comparative example 2 is 1600 N / mm, the actual strength is 1760 N / mm, the bonding performance is tested according to GB / T 6759 N / mm, and the bonding strength is 5.4.

[0045] Comparative Example 3 The difference between Comparative Example 3 and Example 5 is that the temperature of the immersion treatment in step S2 is 180° C. and the reaction time is 30 min; the temperature of the immersion treatment in step S3 is 140° C. and the reaction time is 30 min.

[0046] The design strength of comparative example 3 is 1600 N / mm, the actual strength is 720 N / mm, the bonding performance is tested according to GB / T 6759 N / mm, and the bonding strength is 19.8.

[0047] Comparative Example 4 The difference between Comparative Example 4 and Example 5 is that the temperature of the immersion treatment is 120° C. and the reaction time is 10 min; the temperature of the immersion treatment in step S3 is 130° C. and the reaction time is 20 min.

[0048] The design strength of comparative example 4 is 1600 N / mm, the actual strength is 1690 N / mm, the bonding performance is tested according to GB / T 6759 N / mm, and the bonding strength is 5.6.

[0049] From the strength and bonding strength test results of Example 5 and Comparative Examples 2-4, it can be concluded that if the immersion temperature is too low and the time is too short, the bonding force will be relatively low; if the temperature is too high, the strength loss will be large.

[0050] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A high-strength and lightweight dipped canvas, characterized in that: The dipped canvas comprises a grey cloth, a first impregnation layer arranged on the grey cloth, and a second impregnation layer arranged on the first impregnation layer. The grey cloth is woven from warp yarns and weft yarns (1). The warp yarns comprise main warp yarns (2) and binding warp yarns (3). The main warp yarns (2) are interwoven with the weft yarns (1) and are bound together by the binding warp yarns (3). The main warp yarns are special cords made by twisting a plurality of primary twisted cords. The primary twisted cords comprise inner core fibers and outer layer fibers wrapped around the inner core fibers.

2. The high-strength and lightweight dipped canvas according to claim 1, characterized in that: The binding warp yarn (3) is selected from one or more of nylon 66, nylon 6, polyvinyl alcohol acetal fiber, and polyester fiber, and has a fineness of 550 to 4000 dtex; the binding warp yarn (3) is a twisted yarn obtained by plying and twisting 1 to 5 strands of binding warp yarn.

3. The high-strength and lightweight dipped canvas according to claim 1 is characterized in that: The weft yarn is selected from one or more of nylon 66, nylon 6, polyvinyl alcohol acetal fiber, and polyester fiber, and has a fineness of 550 to 4000 dtex; the weft yarn is a twisted yarn obtained by plying and twisting 1 to 12 strands of weft yarn.

4. The high-strength and lightweight dipped canvas according to claim 1, characterized in that: The inner core fiber is selected from one of ultra-high molecular weight polyethylene fiber and polyarylate fiber.

5. The high-strength and lightweight dipped canvas according to claim 4, characterized in that: The molecular weight of the ultra-high molecular weight polyethylene fiber is greater than 1 million.

6. The high-strength and lightweight dipped canvas according to claim 1, characterized in that: The outer layer fibers are selected from one or more of polyarylate fibers, polyaramid fibers, polyimide fibers, poly(p-phenylene benzobisoxazole) fibers, and polyvinyl acetal fibers.

7. The high-strength and lightweight dipped canvas according to claim 1, characterized in that: The outer layer fibers are wrapped around the outer periphery of the inner core fibers in a parallel and side-by-side manner or in a spirally wound manner by twisting.

8. The high-strength and lightweight dipped canvas according to claim 1, characterized in that: The breaking elongation of the special cord is 2% to 6%, and the fineness is 500dtex to 6000dtex.

9. The method for preparing the high-strength and lightweight dipped canvas according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step S1. Weaving the main warp yarn (2), the binding warp yarn (3) and the weft yarn (1) to form a grey cloth; Step S2. Add the grey cloth obtained in step S1 into the first bath impregnation liquid for impregnation treatment, and dry at 100-120° C. for 20-50 min to obtain a semi-finished product; Step S3. Add the semi-finished product obtained in step S2 into the second bath dipping solution for dipping treatment, and dry it at 110-140° C. for 30-100 min to obtain a high-strength and lightweight dipped canvas.

10. The method for preparing the high-strength and lightweight dipped canvas according to claim 9, characterized in that: In terms of mass percentage, the first bath dipping solution includes 1% to 5% water-soluble epoxy resin, 0 to 2% blocked isocyanate, 0 to 2% water-based curing agent, and the rest is deionized water, and the above total is 100%; the second bath dipping solution includes latex and water-based adhesive, and the solid ratio of latex to water-based adhesive is 85:15 to 60:40; the latex is selected from one or more of butyl latex, natural latex, styrene butadiene latex, carboxylated styrene butadiene, and carboxylated nitrile latex; the water-based adhesive is a phenolic resin aqueous solution or a mixed aqueous solution of a water-soluble epoxy resin and a curing agent, and the curing agent is a blocked isocyanate or a water-based imidazole curing agent.

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