Method of making a fiber rope

Abstract

The present invention relates to a process for preparing a fiber rope. The process comprises the steps of: i) twisting fibers to form a plurality of strands having twist directions of S and Z, respectively; ii) braiding the strands having twist direction of S and the strands having twist direction of Z to form a rope; iii) impregnating the rope obtained in step ii) with an aqueous coating; and iv) subjecting the rope obtained in step iii) to a drawing process to obtain a coated fiber rope. The process of the present invention omits the twisting process, simplifies the process of coating impregnation drying, and increases the strength utilization of the fibers from about 50% to about 60% relative to the process of the prior art. Thus, the production cost is reduced by about 20% and the production cycle is shortened by at least 50%.

Description

Technical Field

[0001] This invention belongs to the field of chemical fiber post-processing technology. Specifically, this invention relates to a method for preparing fiber ropes. Background Technology

[0002] Fiber ropes have existed since ancient times, from early ropes made of twisted natural short fibers such as cotton and linen to modern ropes made of long synthetic fibers such as nylon. In the 1980s, Union Signal (later merged into Honeywell) used its ultra-high molecular weight polyethylene fiber for the development of new fiber ropes, which brought about a new revolution in the rope industry. Today, high-strength chemical synthetic fiber ropes have begun to replace steel wire ropes in many fields. Generally, according to the diameter, twisted or braided fiber bundles below 4mm are called threads, twisted or braided fiber bodies between 4mm and 25mm are called ropes or cords, and twisted or braided fiber bodies above 25mm are called cables or cords.

[0003] With the development and application of high-performance fibers, high-performance fiber braided ropes are becoming increasingly widely used. While the breaking strength of high-performance fiber braided ropes of the same diameter is close to, but still does not exceed, that of conventional steel wire ropes, their material costs are several times higher. The key factors for replacing steel wire ropes are how to improve the breaking strength of high-performance fiber ropes, increase the utilization rate of fiber strength, and simultaneously reduce the manufacturing cost of high-performance fiber ropes.

[0004] Improving the strength utilization rate of ultra-high molecular weight polyethylene (UHMWPE) fibers in ropes is a key technology for producing high-strength UHMWPE braided ropes.

[0005] Currently, ropes with a diameter exceeding 25mm are mainly made by twisting multiple fibers into yarn or rope yarn, then twisting multiple yarns or rope yarn into strands, and finally weaving multiple strands into a rope. For ultra-high molecular weight polyethylene fiber ropes, surface treatments such as coating are required to obtain coated ropes. Specifically, the existing rope weaving process includes: a figure-eight shaped rotating strand tray, a traction disc overcoming the tension of the tray to pull out the interwoven strands, and a winding disc collecting the woven rope; the existing coating process includes: immersing the rope on the winding disc in a coating, drying, and winding it up.

[0006] CN101363197A discloses an ultra-high molecular weight polyethylene rope and its preparation process. The preparation process includes the following steps: 1) selecting raw materials; 2) twisting the yarn; 3) making strands; 4) making the rope; and 5) surface treatment. The surface treatment involves uniformly penetrating the rope body with carefully selected high-quality ethanol or propylene glycol solvent in a specific ratio.

[0007] CN101748558B discloses a method for producing high-strength polyethylene fiber braided high-strength ropes, including selecting high-strength large-tow polyethylene fibers, uniformly tensioning them with a fiber tensioner, twisting and plying multiple bundles of fibers, and then uniformly tensioning and plying the twisted multi-strand fibers according to the rope specifications. The plyed single strands are then uniformly tensioned again and braided into 12-strand ropes using a braiding machine. Finally, the ropes are coated with a surface resin and dried to become high-strength polyethylene fiber ropes.

[0008] The methods described above all involve complex processes such as fiber twisting, strand twisting, rope weaving, and rope coating, resulting in numerous steps and high costs. Furthermore, the fibers undergo repeated wear, reducing their strength utilization rate to approximately 50%. Therefore, there is a desire to provide a method for preparing fiber ropes that can improve the strength utilization rate of the fibers within the rope. Summary of the Invention

[0009] One object of the present invention is to provide a method for preparing fiber ropes, which can improve the strength utilization rate of fibers in the ropes, reduce manufacturing costs, and thus expand the application fields.

[0010] According to a first aspect of the present invention, a method for preparing a fiber rope is provided, characterized in that it comprises the following steps:

[0011] i) The fibers are combined and twisted into several strands with twist directions of S and Z respectively;

[0012] ii) Weave the strands with the S-direction and the strands with the Z-direction into a rope;

[0013] iii) Impregnate the rope obtained in step ii) with an aqueous coating; and

[0014] iv) The rope obtained in step iii) is subjected to a stretching process to obtain a coated fiber rope.

[0015] According to a second aspect of the present invention, a system for preparing fiber ropes is provided, comprising:

[0016] A ply-making machine equipped with several fiber yarn frames; and

[0017] Downstream of the stranding machine is a rope braiding machine, which includes a braiding guide wheel and a traction disc.

[0018] The feature is that an impregnation device is provided between the braided grinding guide wheel and the traction disc.

[0019] According to a third aspect of the invention, a fiber rope prepared by the above method is provided.

[0020] Compared to existing methods, the method for preparing fiber ropes of the present invention can improve the strength utilization rate of fibers by about 20%.

[0021] In the method of this invention, after the braided strands have passed through the grinding joint and the grinding joint guide wheel, a coating impregnation step is added before traction. The traction process squeezes out excess coating, which flows back to the impregnation equipment. This eliminates the need for the subsequent coating process found in the prior art.

[0022] Compared with existing methods, the method of the present invention differs in the following ways: 1) the fibers are directly combined and twisted on a twisting machine to form several rope strands, saving the process of twisting to form yarn; 2) multiple rope strands are woven on a rope braiding machine, then impregnated with coating, stretched, and excess coating is removed to produce coated fiber ropes. This simplifies the coating impregnation and drying process.

[0023] Furthermore, compared to existing methods, the method of the present invention omits the twisting process, simplifies the coating impregnation and drying process, and increases the fiber strength utilization rate from about 50% to about 60%. This reduces production costs by about 20% and shortens the production cycle by at least 50%. Detailed Implementation

[0024] The various aspects of the invention, as well as further objects, features and advantages, will be set forth more fully below.

[0025] According to a first aspect of the present invention, a method for preparing a fiber rope is provided, characterized in that it comprises the following steps:

[0026] i) The fibers are combined and twisted into several strands with twist directions of S and Z respectively;

[0027] ii) Weave the strands with the S-direction and the strands with the Z-direction into a rope;

[0028] iii) Impregnate the rope obtained in step ii) with an aqueous coating; and

[0029] iv) The rope obtained in step iii) is subjected to a stretching process to obtain a coated fiber rope.

[0030] The fiber can be any fiber in the textile industry.

[0031] For example, the fiber can be any type of polymer fiber, preferably selected from high-strength, high-modulus fibers, such as polyolefin fibers (including but not limited to, ultra-high molecular weight polyethylene fibers and polypropylene fibers), aromatic polyamide fibers, and polyamide fibers.

[0032] Particularly preferred fiber types for use in this invention include ultra-high molecular weight polyethylene fiber sold by Honeywell under the trademark Spectra® and "Lilun" fiber sold by Sinopec Yizheng Chemical Fiber. Also preferred are aramid fibers sold by Kolon Industries, Inc. of South Korea under the trademark Heracron®. These fiber types are known in the art and are commercially available.

[0033] Those skilled in the art can select the fineness of the fibers used as needed.

[0034] Preferably, the fineness of the fiber is in the range of 400D-30000D, more preferably in the range of 3000D-10000D, and the monofilament strength is above 4cN / dtex.

[0035] The fibers do not undergo the process of being twisted into yarn before being processed into strands.

[0036] Preferably, the twist of the rope strands obtained in step i) is 5-100 N / m.

[0037] Preferably, the strands with twist directions of S and Z have the same twist.

[0038] The process parameters for preparing rope strands are well known in the field and will not be elaborated here.

[0039] Step i) can be performed on a stock-making machine.

[0040] Preferably, in step ii), the number of strands in the rope with twist directions of S and Z are the same or close.

[0041] Preferably, in step ii), the number of strands with the S-direction and the Z-direction is 2-48. Preferably, the diameter of the rope is in the range of 25-136 mm.

[0042] Preferably, the section of the rope is in the range of 150-1000 mm.

[0043] Preferably, the linear density of the rope is in the range of 400-10000 g / m.

[0044] The process parameters for braiding ropes are well known in this field and will not be elaborated here.

[0045] Step ii) can be performed on a rope braiding machine.

[0046] The water-based coating used in step iii) can be any functional coating used in the textile industry for coating fibers or ropes, such as those used to improve the abrasion resistance, high temperature resistance, and water resistance of ropes.

[0047] In some embodiments, the aqueous coating comprises a resin binder.

[0048] Suitable resin adhesives include, but are not limited to, waterborne polyurethanes, waterborne acrylic resins, waterborne polyester resins, waterborne silicone-containing and fluorine-containing resins, waterborne amino resins, waterborne alkyd resins, waterborne epoxy resins, waterborne phenolic resins, waterborne oils and waterborne polybutadiene, waterborne hyperbranched polymers and combinations thereof.

[0049] Preferably, the resin adhesive is selected from waterborne polyurethane, waterborne acrylic resin, and combinations thereof.

[0050] More preferably, the resin adhesive is selected from waterborne polyurethane. The waterborne polyurethane is commercially available, for example, Impranil DL1537 and Impranil DLH waterborne polyurethanes from Covestro; ICO-THANE 10 and ICO-THANE 96 waterborne polyurethanes from I-Coat (Belgium); and XL-901 and XL-902 waterborne polyurethanes from Jiangsu Xinglong Optoelectronics Co., Ltd.

[0051] Preferably, the resin binder is present in the water-based coating in an amount ranging from 3% to 65% by weight, based on the total weight of the water-based coating.

[0052] The aqueous coating may optionally contain other additives, including but not limited to wetting agents, leveling agents, defoamers, light stabilizers, and pigments. Those skilled in the art can select the appropriate type and amount of additives according to actual needs.

[0053] The water-based coating can be formulated using any suitable method known to those skilled in the art.

[0054] Preferably, in step iii), the rope is immersed in an aqueous coating for 0.1-600 seconds, more preferably 0.1-300 seconds, and more preferably 0.5-100 seconds.

[0055] In the stretching process, the rope is stretched and excess paint is removed under the pressure of the stretching disc.

[0056] In this application, "excessive coating" refers to coating that is too much relative to achieving the target amount of adhesive.

[0057] Those skilled in the art can adjust the pressure of the draw roller on the rope according to the target amount of adhesive on the fiber to expel excess coating.

[0058] Preferably, the amount of adhesive applied to the fiber rope is 1% to 25% by weight, more preferably 2% to 20% by weight, relative to the weight of the fiber rope.

[0059] The amount of adhesive applied to the fiber rope is calculated using the following formula:

[0060] Fiber rope adhesive application amount = (weight of fiber rope - weight of uncoated fiber rope) / weight of fiber rope

[0061] The weight of uncoated fiber rope refers to the weight of the fiber rope obtained after the fibers undergo the same process but without impregnation.

[0062] Step iii) can be carried out using the impregnation equipment of a rope braiding machine.

[0063] Preferably, in step iv), the draw ratio is in the range of 1.001-1.1, and more preferably in the range of 1.005-1.05.

[0064] Step iv) can be performed using the draw plate of a rope braiding machine.

[0065] After step iv), the resulting fiber rope can be directly wound onto a take-up reel, or it can be dried at a certain temperature and then wound onto a take-up reel.

[0066] Those skilled in the art can determine the drying temperature and time based on the coating and the amount of adhesive used.

[0067] Alternatively, the winding reel with the fiber rope can be left to air dry or sun dry.

[0068] According to a second aspect of the present invention, a system for preparing fiber ropes is provided, comprising:

[0069] A ply-making machine equipped with several fiber yarn frames; and

[0070] In the downstream rope braiding machine, the rope braiding machine includes a braiding guide wheel and a traction disc.

[0071] The feature is that an impregnation device is provided between the braided grinding guide wheel and the traction disc.

[0072] The number of fiber yarn frames can be set according to actual needs, for example, it can be 50-2000.

[0073] Preferably, the system further includes a winding machine, which includes a winding reel.

[0074] The stranding machine and the winding machine are commonly used equipment in the field of fiber rope preparation, and will not be described in detail here.

[0075] Apart from the impregnation equipment, the rope braiding machine is basically the same as the rope braiding machine commonly used in the field of fiber rope preparation.

[0076] Preferably, a guide plate or guide groove is provided below the traction disc to guide excess coating squeezed off the fiber rope to the impregnation equipment.

[0077] The impregnation equipment can be, for example, an impregnation tank.

[0078] In some implementations, the fibers are placed on a fiber support, guided from the fiber support to a stranding machine to form strands, the strands are guided to a rope braiding machine to interweave, pass through a grinding wheel and a grinding wheel guide, and then guided to a drawing plate by an impregnation device. The drawing plate draws and squeezes to remove excess coating to obtain a coated fiber rope, which is then wound onto a winding reel by a winding machine.

[0079] According to a third aspect of the invention, a fiber rope prepared by the above method is provided.

[0080] The terms "comprising" and "including" as used in this application cover situations where other elements not explicitly mentioned are also included, as well as situations where the elements mentioned are constituted.

[0081] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of any discrepancy between the definitions of terms in this specification and their commonly understood meaning by one of ordinary skill in the art to which this invention pertains, the definitions set forth herein shall prevail.

[0082] Unless otherwise stated, all numerical values ​​for the amounts of expressed components, process conditions, etc., used in the specification and claims are to be understood as being modified by the term "about". Therefore, unless otherwise indicated, the numerical parameters set forth herein are approximate values ​​that can be varied to obtain the desired performance.

[0083] Example

[0084] The following will further illustrate the concept and technical effects of the present invention with reference to embodiments, so that those skilled in the art can fully understand the purpose, features, and effects of the present invention. It should be understood that some embodiments are merely illustrative and do not constitute a limitation on the scope of the present invention.

[0085] Comparative Example 1

[0086] Five HMPE fibers (Spectra S900, 5600D, with a breaking strength of 1.4 kN, purchased from Honeywell) were twisted on a twisting machine to produce a twist of 20 n / m. This resulted in 22 twists, 11 in the S-direction and 11 in the Z-direction.

[0087] Eleven S-twist yarns are twisted into strands on a stranding machine, with a twist of 11 n / m. The total number of strands produced is six (Z-direction).

[0088] Eleven Z-twist yarns are twisted into strands on a stranding machine, with a twist of 11 n / m. The total number of strands produced is six (S-direction).

[0089] The 12 strands prepared above are braided into a rope on a rope braiding machine with a cross section of 220 mm and a linear density of 455 g / m.

[0090] The rope obtained by impregnating it with the coating prepared as follows (impregnation time is 20 seconds) and then stretching the rope through a stretching disc and squeezing to remove excess coating is obtained to obtain a coated fiber rope:

[0091] Impranil DL1537 waterborne polyurethane purchased from Covestro was mixed with deionized water at a weight ratio of 1:1 until homogeneous.

[0092] The draw ratio during the draw process is 1.01.

[0093] The resulting fiber rope has a diameter of 28 mm, a cross section of 222 mm, a linear density of 480 g / m, and an impregnation amount of 5.1% by weight relative to the total weight of the fiber rope. The breaking strength measured according to ISO 10325 is 509 kN.

[0094] Invention Embodiment 1

[0095] Fifty-five HMPE fibers (Spectra S900, 5600D, with a breaking strength of 1.4 kN, purchased from Honeywell) were twisted into strands on a stranding machine with a twist of 11 n / m. The resulting strands comprised 12 strands, six in the S-direction and six in the Z-direction.

[0096] The 12 strands prepared above are braided into a rope on a rope braiding machine with a cross section of 220 mm and a linear density of 450 g / m.

[0097] The rope obtained by impregnating it with the coating prepared as follows (impregnation time is 20 seconds) and then stretching the rope through a stretching disc and squeezing to remove excess coating is obtained to obtain a coated fiber rope:

[0098] Impranil DL1537, purchased from Covestro, was mixed with deionized water at a weight ratio of 1:1.

[0099] The draw ratio during the draw process is 1.01.

[0100] The resulting fiber rope has a diameter of 28 mm, a cross section of 222 mm, a linear density of 476 g / m, and an impregnation amount of 5.4% by weight relative to the total weight of the fiber rope. The breaking strength measured according to ISO 10325 is 606 kN.

[0101] Compared with the rope prepared in Comparative Example 1, the breaking strength of the fiber rope of Invention Example 1 is increased by 19%.

[0102] While some aspects of the invention have been shown and discussed, those skilled in the art will recognize that changes can be made to these aspects without departing from the principles and spirit of the invention, and therefore the scope of the invention will be defined by the claims and their equivalents.

Claims

1. A method for preparing fiber ropes, characterized in that, It includes the following steps: i) The fibers are combined and twisted into several strands with twist directions of S and Z respectively; ii) Weave the strands with the S-direction and the strands with the Z-direction into a rope; iii) Impregnate the rope obtained in step ii) with an aqueous coating; and iv) The rope obtained in step iii) is subjected to a stretching process to stretch the rope and remove excess coating under pressure, resulting in a coated fiber rope with a stretch ratio in the range of 1.001-1.

1. The method is carried out in a system for preparing fiber ropes, and includes: A ply-making machine equipped with several fiber yarn frames; and Downstream of the stranding machine is a rope braiding machine, which includes braiding guide rollers and a drafting disc. An impregnation device is provided between the braiding guide wheel and the drawing disc.

2. The method according to claim 1, characterized in that, The fibers are selected from high-strength, high-modulus fibers.

3. The method according to claim 1, characterized in that, The fibers are selected from polyolefin fibers, aromatic polyamide fibers, and polyamide fibers.

4. The method according to claim 1, characterized in that, The fibers are selected from ultra-high molecular weight polyethylene fibers and polypropylene fibers.

5. The method according to claim 1 or 2, characterized in that, The fineness of the fiber is in the range of 400D-30000D, and the monofilament strength is above 4cN / dtex.

6. The method according to claim 5, characterized in that, The fineness of the fiber is in the range of 3000D-10000D.

7. The method according to any one of claims 1 to 3, characterized in that, The twist of the rope strands obtained in step i) is 5-100 N / m.

8. The method according to any one of claims 1 to 3, characterized in that, The strands with twist directions of S and Z have the same twist.

9. The method according to any one of claims 1 to 3, characterized in that, In step ii), the number of strands with the twist direction S and the number of strands with the twist direction Z are 2-48.

10. The method according to any one of claims 1 to 3, characterized in that, The water-based coating contains a resin binder.

11. The method according to claim 10, characterized in that, The resin binder is present in the aqueous coating in an amount ranging from 3% to 65% by weight, based on the total weight of the aqueous coating.

12. The method according to claim 10, characterized in that, The resin adhesive is selected from waterborne polyurethane, waterborne acrylic resin, waterborne polyester resin, waterborne silicone-containing resin, fluorine-containing resin, waterborne amino resin, waterborne alkyd resin, waterborne epoxy resin, waterborne phenolic resin, waterborne oil, waterborne polybutadiene, waterborne hyperbranched polymer, and combinations thereof.

13. The method according to any one of claims 1 to 3, characterized in that, In step iv), the draw ratio is in the range of 1.005-1.

05.

14. The method according to claim 1, characterized in that, A guide plate or guide trough is provided below the drawing plate to guide the excess coating squeezed off the fiber rope to the impregnation equipment.

15. A fiber rope prepared by the method according to any one of claims 1 to 14.