Rapier loom device for preparing degradable monofilament net type sand barrier and preparation method thereof

Abstract

The invention relates to the technical field of textile fiber products, and discloses a rapier loom device for preparing a degradable monofilament net type sand barrier and a preparation method thereof.The rapier loom device for preparing the degradable monofilament net type sand barrier comprises a rapier loom body, a support arranged in the middle of the rapier loom body and a weft insertion mechanism arranged at the top of the support. By arranging the weft insertion mechanism, the stressed area of the monofilament weft yarn is increased when the monofilament weft yarn is dragged, stress is dispersed, and the situation that a single part is fractured due to the fact that the single part bears too large pressure is reduced. The preparation method of the degradable monofilament net type sand barrier comprises the steps that polylactic acid monofilaments with the diameter being 0.2-0.4 mm are used as sand barrier woven fabric, and the weft density is alternately changed by 10-30 pieces / 10 cm and 30-60 pieces / 10 cm. The prepared net type sand barrier woven fabric has high stiffness without being subjected to stiffness finishing, and can be composted and degraded. Meanwhile, natural wrinkles can be formed without depending on a specially-designed laying machine in laying construction, and the method has advantages when applied to desert ecological restoration.

Description

Technical Field

[0001] The present invention relates to the technical field of textile fiber products, in particular to a rapier loom device for preparing a degradable monofilament net-type sand barrier and a preparation method thereof. Background Art

[0002] Sand barriers are a common method for preventing wind and sand in arid and semi-arid regions. They physically slow down windblown sand, thus preventing wind and sand from spreading. Compared to traditional straw grid or fence-type sand barriers, net-type sand barriers are more amenable to mechanized and large-scale construction. Currently, the warp and weft yarns of net-type sand barriers primarily consist of yarn spun from single fibers (such as cotton or viscose) or polyethylene monofilament. Of these two materials, sand barriers made from short-staple yarns are prone to lodging and typically require stiffening, which directly increases their cost. Sand barriers made from polyethylene monofilaments are prone to degradation and are ecologically unfriendly. Considering both lodging resistance and ecological degradation requirements, using coarse polylactic acid monofilaments (0.2 mm diameter) to construct net-type sand barriers is a viable and advantageous solution.

[0003] From an application perspective, woven sand barrier fabrics need to have a pleated shape after installation to improve wind resistance and lodging resistance. Traditional woven fabric sand barriers (with a constant warp and weft density) cannot automatically form pleats and require the assistance of sand-fixing machinery, which places complex demands on sand barrier installation machinery. From a fabric perspective, intermittently varying the weft density can promote pleating, thereby reducing the requirements for sand barrier installation machinery. This type of net-type sand barrier automatically forms pleats after installation, providing natural lodging resistance. Currently, no woven fabric designs for sand barriers of this type are available in the industry. Due to the inherent brittleness of polylactic acid (PLA) polymer, coarse PLA monofilaments (0.2mm diameter) are typically brittle and stiff, posing challenges to the weaving process. Major issues include long downtime and low weaving efficiency, necessitating improvements to the rapier loom mechanism. The rapier head of a conventional rapier loom secures the weft yarn using a precise mechanical or pneumatic clamping mechanism, and its design directly impacts weft insertion reliability and weaving efficiency. Currently, over 80% of rapier looms use elastic grippers to clamp the weft yarn. These grippers are made of high-carbon steel or titanium alloy, and their clamping force (typically 0.5-3N, adjustable) is generated by a preloaded spring. The gripper's opening and closing timing is controlled by a trigger cam, synchronized with the loom's main shaft. To enhance gripping force, the gripper surface is often designed with a fine tooth pattern (pitch 0.2-0.5mm) to increase friction. The gripper's gripping control is generally effective when the weft yarn is a soft, staple-fiber yarn. However, when the weft yarn is monofilament, particularly the thick, brittle polylactic acid monofilament, insufficient effective clamping area can occur. In such cases, stress concentration is easily generated in the weft monofilament during high-speed movement. Furthermore, the weft monofilament is subjected to significant impact and bending stress during the splicing process, leading to breakage or yarn slippage. Therefore, a specialized rapier gripper device is required to handle coarse, monofilament sand barriers. On the one hand, it solves the problem of weft monofilament breakage caused by low effective clamping area and large local stress; on the other hand, it solves the problem of weft monofilament breakage or weft detection failure caused by excessive tension fluctuation during the intersection of the rapier head and the movement of the cloth fell.

[0004] Rapier looms play a key role in producing sand barrier fabrics. The reciprocating motion of the rapier precisely guides the weft yarn into the weft shed, where it forms a compact woven fabric alongside the warp yarn. This flexible loom allows for customized adjustments in fabric density and width, ensuring the sand barrier possesses sufficient strength and stability. The high efficiency of the rapier loom significantly improves production efficiency and shortens the manufacturing cycle for sand barriers. The use of rapier looms has significantly enhanced the quality and performance of sand barriers, providing strong support for sand control and prevention projects.

[0005] Rapier looms are widely used in the textile industry, but due to the limitations of their structure and working principle, they often have some problems that cannot be ignored. During the weft delivery stage, the rapier uses rapid reciprocating motion to deliver the weft yarn from the supply side to the receiving side. Due to the limited contact area between the rapier and the weft yarn, the weft yarn is subject to large friction and tension during high-speed movement, which can easily cause local stress concentration and lead to weft breakage. At the same time, the rapier needs to overcome a certain amount of resistance during the weft delivery process, which further increases the force on the weft yarn. During the weft receiving stage, the weft receiving rapier also faces similar problems. In addition, due to the small contact area between the weft delivery and receiving rapiers and the weft yarn, the weft yarn is subject to large impact force and bending stress during the weft receiving process, which can also easily lead to weft breakage. Summary of the Invention

[0006] In view of the problem in the existing technology that the weft yarn is easily broken during the weft insertion process of the rapier loom, a rapier loom device for preparing a degradable monofilament net type sand barrier is proposed.

[0007] The purpose is to reduce the probability of thread breakage by increasing the contact area between the rapier loom and the end of the weft yarn and reducing the curvature of the weft yarn when it is pulled.

[0008] The technical solution of the present invention is a rapier loom device for preparing a degradable monofilament net-type sand barrier, comprising a rapier loom body, a bracket arranged in the middle of the rapier loom body, a weft insertion mechanism arranged on the top of the bracket, and a clamping mechanism arranged on the top of the weft insertion mechanism; The weft insertion mechanism includes a housing 1 disposed on the top of the bracket, a double-layer cavity provided inside the housing, clamping arms 1 disposed on both sides of the lower layer of the double-layer cavity, a pulling unit symmetrically disposed on the upper layer of the double-layer cavity, two ends of a tension spring fixedly connected to the rotary arms and the upper layer of the double-layer cavity respectively, a lower transverse plate disposed on the side of the bracket close to the lower push rod, the lower push rod disposed outside the housing 1, a reciprocating transverse plate disposed on the side of the bracket opposite to the lower push rod, and a weft joining unit disposed on the side of the bracket away from the housing 1. The lower layer of the double-layer cavity accommodates clamping arm 1, and the upper layer of the double-layer cavity accommodates the pulling unit. The pulling unit drives clamping arm 1 to move, the lower horizontal plate squeezes the pulling unit on the corresponding side, and the reciprocating horizontal plate squeezes the other pulling unit on the corresponding side. After the pulling unit is squeezed, it drives the corresponding clamping arm 1 to move.

[0009] Furthermore, the pulling unit includes a support shaft symmetrically arranged on the upper layer of the double-layer cavity, a rotary arm arranged on the outside of the support shaft, a guide rail arranged on one end of the rotary arm close to the support shaft, the guide rail is connected to the corresponding clamping arm in a limited sliding manner, and a tension spring arranged in the middle of the rotary arm.

[0010] Furthermore, the end of the swing arm away from the support shaft is provided with two branches, and the two branches are at different heights, wherein the lower branch is at the same height as the lower cross plate and the lower push rod, and the thickness of the reciprocating cross plate is equal to the thickness of the swing arm on the corresponding side.

[0011] Furthermore, the weft splicing unit includes a shell 2 arranged on the side of the bracket away from the shell 1, the structure of the shell 2 is symmetrical to the structure of the shell 1, clamping arms 2 are arranged on both sides of the lower layer of the double-layer cavity of the shell 2, another pulling unit is arranged on the upper layer of the double-layer cavity of the shell 2, a torsion spring is sleeved on the top of the clamping arm 2, a cross arm is arranged on the top of the torsion spring, the two ends of the torsion spring are respectively fixedly connected to the cross arm and the clamping arm 2, an upper push rod is arranged on the side of the shell 2 close to the corresponding pulling unit, the clamping arm 2 on the side away from the upper push rod is fixedly connected to the shell 2, and an upper cross plate is arranged on one end of the bracket close to the upper push rod.

[0012] Furthermore, the upper horizontal plate and the upper push rod have the same height, and the higher branch of the rotary arm corresponding to the second housing has the same height as the upper horizontal plate.

[0013] Furthermore, the clamping mechanism includes pressure plates respectively arranged on the top of clamping arm one and clamping arm two, a rotating block arranged on the side where two adjacent pressure plates are close to each other, the rotating block is rotatably connected to the pressure plate, a rubber plate arranged on the side where the rotating blocks are close to each other, and a short rod arranged in the middle of the pressure plate on the side closest to the lower horizontal plate.

[0014] Furthermore, the pressing plate is elliptical and the outer shape of the rotating block is truncated cone.

[0015] Another object of the present invention is to provide a method for preparing a degradable monofilament mesh sand barrier, the purpose of which is to use a weaving method to prepare a sand barrier with the function of intercepting sand and gravel.

[0016] To achieve the above-mentioned object, the present invention provides the following technical solution: a method for preparing a degradable monofilament net-type sand barrier, comprising the following steps: First, select the monofilament with a diameter of 0.2-0.4mm, a strength of 2.5-3.5cN / dtex, an elongation at break of 25-35%, and a Young's modulus of 25-45cN / dtex; Secondly, after the monofilament warp is threaded, the weft yarn is pulled by the weft insertion mechanism and the clamping mechanism to weave the monofilament in the warp and weft directions into a sand barrier. The fabric structure can be plain or twill, with a width of 60-120cm. Finally, the sand barrier has a warp density of 30-80 strands / 10cm and a weft density of 10-30 strands / 10cm and 30-60 strands / 10cm alternatingly.

[0017] Furthermore, the monofilaments constituting the sand barrier are composed of three parts: polylactic acid, calcium carbonate and polycaprolactone or polybutylene terephthalate-adipate, wherein the mass percentage of polycaprolactone or polybutylene terephthalate-adipate is 0-15%, and the mass percentage of calcium carbonate is 0-5%.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. By setting up a weft insertion mechanism, during the weft yarn transportation process, the weft yarn is fixed by squeezing two parallel surfaces, and the pressure is evenly applied to the weft yarn to keep the weft yarn in a stable state. Compared with the traditional method of fixing the weft yarn by yarn clamping pieces, the weft insertion mechanism allows the weft yarn to form effective contact with the clamping component, increasing the force area. The weft yarn fixed by the yarn clamping piece may face the risk of breakage due to concentrated force during movement. Now that the force area is increased, the stress is dispersed, and the situation where a single part is subjected to excessive pressure is reduced. In this way, the weft yarn can pass through the warp yarn more smoothly during the weft delivery process, avoiding the problem of broken thread caused by excessive local force or severe vibration. This design of the weft delivery mechanism ensures the continuity and integrity of the weft yarn during the weaving process, enables the loom to work continuously and stably, and improves weaving efficiency and product quality.

[0019] 2. By setting up a weft splicing unit, when the weft yarn is sent to the weft splicing position, the weft splicing unit also contacts the weft yarn by squeezing two parallel surfaces, avoiding excessive pulling or bending of the weft yarn by traditional yarn clamps at the moment of splicing. The weft splicing unit makes the weft yarn evenly stressed during the splicing process, preventing stress from being concentrated at a certain point of the weft yarn. In this way, the weft yarn will not be broken due to sudden excessive stress at a certain point. The weft splicing unit ensures that the process of the weft yarn from sending the weft yarn to being woven into the fabric is continuous and smooth, maintaining the integrity of the weft yarn.

[0020] 3. By setting up a clamping mechanism, when the two corresponding rotor blocks clamp the weft yarn and start to move, the weft yarn will generate a pulling force on the rotor block, and the pulled rotor block will rotate accordingly. This rotation action adjusts the shape of the weft yarn, which makes the weft yarn of the clamped part and the weft yarn of the unclamped part remain in a horizontal state. Compared with the traditional rapier clamping the thread end through the yarn clamping piece, the clamping mechanism reduces the bending amplitude of the weft yarn in the clamping area. The larger bending that may have existed originally can be alleviated under the action of the rotor block rotation, avoiding the weft yarn from being subjected to excessive stress at the bending point. The setting of the clamping mechanism makes the loom adaptable to the weaving of high modulus monofilament weft yarn, makes the weft yarn smoother during movement, reduces the risk of breakage, and the design of the rotor block allows the weft yarn to maintain a good state during the weaving process.

[0021] 4. Using coarse polylactic acid monofilaments with a diameter greater than 0.2mm to produce sand barrier woven fabrics: Polylactic acid raw materials have the advantage of being compostable compared to polyethylene raw materials, which alleviates concerns about sand barrier degradation. Compared to short-fiber yarns, coarse-diameter monofilaments have the advantage of high modulus and stiffness. Once made into sand barrier woven fabrics, the fabrics are inherently stiff, eliminating the need for stiffening finishing and can be used directly for windbreak and sand fixation.

[0022] 5. Use variable weft density woven fabric design: While maintaining a constant warp density, the weft density is alternating between 10-30 threads / 10cm and 30-60 threads / 10cm. After installation, this alternating weft density sand barrier fabric forms wrinkles more easily than a single weft density sand barrier, providing a more effective means of preventing wind and sand from being lost. Furthermore, this variable weft density sand barrier creates natural wrinkles without the need for specially designed laying machinery, saving construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the overall three-dimensional structure of the rapier loom of the present invention; Figure 2 Schematic diagram of the overall structure of the bracket of the rapier loom of the present invention; Figure 3 Schematic diagram of the connection between the support and the weft insertion mechanism of the rapier loom of the present invention; Figure 4 Schematic diagram of the connection between the bracket, the lower cross plate and the reciprocating cross plate of the rapier loom of the present invention; Figure 5 Schematic diagram of the connection between the housing 1 and the lower push rod of the rapier loom of the present invention; Figure 6 Schematic diagram of the connection between the clamping arm 1 and the housing 1 of the rapier loom of the present invention; Figure 7 It is a schematic diagram of the connection between the pulling unit and the housing of the rapier loom of the present invention; Figure 8 Schematic diagram of the overall structure of the pulling unit of the rapier loom of the present invention; Figure 9 Schematic diagram of the overall structure of the weft joining unit of the rapier loom of the present invention; Figure 10 Schematic diagram of the connection between the second housing and the second clamping arm of the rapier loom of the present invention; Figure 11 Schematic diagram of the internal structure of the second housing of the rapier loom of the present invention; Figure 12 Schematic diagram of the connection between the cross arm and the second clamping arm of the rapier loom of the present invention; Figure 13 It is a schematic diagram of the connection between the pressing plate and the short rod of the rapier loom of the present invention.

[0024] In the picture: 1. Rapier loom body; 2. Bracket; 3. Weft insertion mechanism; 4. Clamping mechanism; 31. Housing 1; 32. Double cavity; 33. Clamping arm 1; 34. Lower cross plate; 35. Lower push rod; 36. Reciprocating cross plate; 37. Support shaft; 38. Rotating arm; 39. Guide rail; 310. Tension spring; 311. Housing 2; 312. Clamping arm 2; 313. Torsion spring; 314. Cross arm; 315. Upper push rod; 316. Upper cross plate; 41. Pressing plate; 42. Rotating block; 43. Rubber plate; 44. Short rod. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0026] Example 1, reference Figures 1-13 , which is the first embodiment of the present invention, provides a rapier loom device for preparing a degradable monofilament net type sand barrier, including a rapier loom body 1, a bracket 2 fixedly connected to the middle of the rapier loom body 1, a weft insertion mechanism 3 installed on the top of the bracket 2, and a clamping mechanism 4 installed on the top of the weft insertion mechanism 3; the weft insertion mechanism 3 includes a shell 31 fixedly connected to the top of the bracket 2, a double-layer cavity 32 opened inside the shell, a clamping arm 33 slidably connected to both sides of the lower layer of the double-layer cavity 32, a pulling unit symmetrically assembled on the upper layer of the double-layer cavity 32, and two ends of the tension spring 310 are respectively connected to the rotary arm 38 and the upper layer of the double-layer cavity 32. The layers are fixedly connected, the lower transverse plate 34 is fixedly connected to the side of the bracket 2 close to the lower push rod 35, the lower push rod 35 is fixedly connected to the outside of the shell 31, the reciprocating transverse plate 36 is fixedly connected to the bracket 2 on the opposite side of the lower push rod 35, and the weft joining unit is assembled on the side of the bracket 2 away from the shell 31; the lower layer of the double-layer cavity 32 accommodates the clamping arm 33, and the upper layer of the double-layer cavity 32 accommodates the pulling unit, the pulling unit drives the clamping arm 33 to move, the lower transverse plate 34 squeezes the pulling unit on the corresponding side, and the reciprocating transverse plate 36 squeezes the other pulling unit on the corresponding side, and after the pulling unit is squeezed, it drives the corresponding clamping arm 33 to move.

[0027] Specifically, two ends of the bracket 2 are respectively provided with sword rods, which push the shell 1 31 and the shell 2 311 to move respectively. When the shell 1 31 moves, it drives other parts connected to it to move together. The lower layer of the double-layer cavity 32 accommodates the clamping arm 1 33 to slide inside, and the upper layer of the double-layer cavity 32 accommodates the pulling unit to move inside. The lower cross plate 34 squeezes the passing swing arm 38, forcing the swing arm 38 to rotate. After the shell 1 31 and the shell 2 311 approach each other to the maximum stroke, the lower push rod 35 pushes the corresponding swing arm 38 on the same side of the shell 2 311, and the lower cross plate 34 squeezes the corresponding swing arm 38 on the same side that moves with the shell 1 31. The reciprocating cross rod squeezes the corresponding swing arm 38 on the same side that moves with the shell 1 31 to rotate it. When the shell 1 drives the swing arms 38 on the corresponding two pulling units to move and reset, the swing arm 38 close to the reciprocating cross plate 36 will be pushed by it during the movement and reset process, thereby rotating.

[0028] Reference Figure 7 The pulling unit includes a support shaft 37 symmetrically fixedly connected to the upper layer of the double-layer cavity 32, a rotary arm 38 rotatably connected to the outside of the support shaft 37, a guide rail 39 fixedly connected to one end of the rotary arm 38 near the support shaft 37, the guide rail 39 is connected to the corresponding clamping arm in a limited sliding connection, and a tension spring 310 fixedly connected to the middle of the rotary arm 38.

[0029] Specifically, the support shaft 37 constrains the position of the swing arm 38 so that it can only rotate around the support shaft 37. The swing arm 38 will rotate after being squeezed by the outside world, and the guide rail 39 rotates with the swing arm 38. While the guide rail 39 rotates, it drives the corresponding clamping arm 33 to move. The tension spring 310 maintains the traction force on the swing arm 38, so that the swing arm 38 remains in contact with the shell 31.

[0030] Reference Figures 1-9 The end of the rotary arm 38 away from the support shaft 37 is provided with two branches, and the two branches are at different heights, wherein the lower branch is at the same height as the lower cross plate 34 and the lower push rod 35, and the thickness of the reciprocating cross plate 36 is equal to the thickness of the rotary arm 38 on the corresponding side.

[0031] Specifically, when the rotary arm 38 moves back and forth with the shell 31, the two branches will rotate in the opposite direction after being squeezed by the upper cross plate 316 or the lower cross plate 34. The upper cross plate 316 and the lower cross plate 34 only push the branches of the rotary arm 38 on the same side and at the same height as themselves.

[0032] Reference Figures 1-12The weft splicing unit includes a second shell 311 fixedly connected to the side of the bracket 2 away from the first shell 31, the structure of the second shell 311 is symmetrical to the structure of the first shell 31, a second clamping arm 312 slidably connected to both sides of the lower layer of the double-layer cavity 32 of the second shell 311, another pulling unit assembled on the upper layer of the double-layer cavity 32 of the second shell 311, a torsion spring 313 sleeved on the top of the second clamping arm 312, a cross arm 314 fixedly connected to the top of the torsion spring 313, two ends of the torsion spring 313 are respectively fixedly connected to the cross arm 314 and the second clamping arm 312, an upper push rod 315 fixedly connected to the side of the second shell 311 close to the corresponding pulling unit, the second clamping arm 312 away from the side of the upper push rod 315 is fixedly connected to the second shell 311, and an upper horizontal plate 316 fixedly connected to one end of the bracket 2 close to the upper push rod 315.

[0033] Specifically, the structure of the second shell 311 is symmetrical with that of the first shell 31. Among the two second clamping arms 312, the second clamping arm 312 away from the upper push rod 315 is fixedly connected to the second shell 311, and the other second clamping arm 312 is driven by the pulling unit corresponding to the second shell 311. The second shell 311 moves back and forth with the corresponding rapier on the bracket 2, and at the same time drives the second clamping arm 312 to move together. The second clamping arm 312 drives the cross arm 314 to move together, and the push rod pushes the passing rotary arm 38, and the upper cross plate 316 also pushes the passing rotary arm 38.

[0034] Reference Figure 9 The upper horizontal plate 316 and the upper push rod 315 have the same height, and the higher branch of the rotary arm 38 corresponding to the second housing 311 has the same height as the upper horizontal plate 316 .

[0035] Specifically, the upper horizontal plate 316 presses the corresponding rotary arm 38 on the same side that moves with the second housing 311 , and presumably presses the corresponding rotary arm 38 on the same side that moves with the first housing 31 .

[0036] Example 2, reference Figures 1-13 The clamping mechanism 4 includes a pressure plate 41 fixedly connected to the top of the clamping arm 1 33 and the clamping arm 2 312 respectively, a rotating block 42 rotatably connected to the side where the two adjacent pressure plates 41 are close to each other, the rotating block 42 is rotatably connected to the pressure plate 41, a rubber plate 43 fixedly connected to the side where the rotating block 42 is close to each other, and a short rod 44 fixedly connected to the middle part of the pressure plate 41 on the side closest to the lower horizontal plate 34.

[0037] When the cam 314 is in the process of being moved along with the outer shell 31, the short rod 44 will first contact the end of the weft yarn, and as the short rod 44 moves, the weft yarn will be pulled to a nearly horizontal state for easy clamping.

[0038] Reference Figure 13 The pressing plate 41 is elliptical and the outer shape of the rotating block 42 is truncated cone.

[0039] Specifically, since the pressure plate 41 is elliptical, when the distal ends of the pressure plates 41 that are in the same plane and have different circular heights squeeze each other, the two pressure plates 41 will be misaligned with each other, and the turning block 42 has an outer circle with a conical surface through the truncated cone, so that after the weft yarn contacts the side of the turning block 42, it will move toward the side with the rubber plate 43 under the guidance of the conical surface. The rest of the structure is the same as that of Example 1.

[0040] In summary, the working principle of the present invention is as follows: during weft insertion, the bracket 2 drives the housing 1 31 and the housing 2 311 to move back and forth, approaching and resetting each other, through the rapier. The housing 1 31 moves toward the housing while driving the two clamping arms 1 33 and the corresponding two pulling units to move. The rotary arm 38 on the side of the housing 1 31 close to the reciprocating horizontal plate 36 will be pushed when passing through the reciprocating horizontal plate 36, thereby generating rotation and pointing to the other direction under the action of the corresponding tension spring 310. While rotating, it drives the corresponding clamping arm 1 33 toward the other clamping arm 3 3 moves, and drives the corresponding rotating block 42 to move until it contacts the rotating block 42 on the other clamping arm 33. Since the short rod 44 has guided the weft yarn on the moving path in advance, the rotating blocks 42 on the two clamping arms 33 clamp the weft yarn through the rubber plate 43 at this time, so that the weft yarn moves together with the shell 31. After the weft yarn is pulled and tensioned, the reaction force of the pulling is transmitted to the corresponding two rotating blocks 42, and the two rotating blocks 42 rotate, so that the clamped part and the unclamped part of the weft yarn remain in a nearly straight line, avoiding the weft yarn from breaking due to excessive bending; When the weft yarn is connected, the upper push rod 315 pushes the rotary arm 38 on the same side of the shell 1 31 to drive the corresponding clamping arm 1 33 to move away from the other clamping arm, thereby releasing the clamping of the weft yarn. When the handover is completed, the shell 1 31 and the shell 2 311 move away from each other, and the weft joining unit drives the weft yarn to the weft joining side of the loom. During the reset process of the shell 1 31, the reciprocating horizontal plate 36 pushes the corresponding rotary arm 38, driving the corresponding clamping arm to reset. The lower horizontal plate 34 pushes the corresponding rotary arm 38 on the same side of the shell 1 31 to reset it. After the shell 2 311 is reset, the corresponding rotary arm 38 is pushed by the upper horizontal plate 316 and reset, preparing for the next weft insertion.

[0041] Example 3, reference Figures 1-13 , as a third embodiment of the present invention, provides: a method for preparing a degradable monofilament net-type sand barrier, comprising the following steps: S1. First, select monofilaments with a diameter of 0.2-0.4 mm, a strength of 2.5-3.5 cN / dtex, an elongation at break of 25-35%, and a Young's modulus of 25-45 cN / dtex. Polylactic acid monofilaments (90% polylactic acid and 10% polybutylene terephthalate-adipate) and polylactic acid staple yarns of comparable thickness are woven into a sand barrier with a warp and weft density of 50 yarns / 10 cm. Test the bending length of the sand barrier fabric according to GB / T18318-2001 and the percentage increase in the vertical projected area of ​​the sand barrier after a strong wind of 13.8 m / s. The results are shown in Table 1: Table 1 Differences between polylactic acid monofilament and polylactic acid yarn net sand barriers

[0042] It can be seen from Table 1 that when the yarn diameter is the same, the bending length of the monofilament sand barrier is better than that of the yarn structure net sand barrier. In addition, the increase rate of the vertical projection area of ​​the monofilament structure net sand barrier after encountering strong wind is also significantly lower than that of the yarn structure net sand barrier. The above results show that the monofilament sand barrier has a significant advantage in stiffness performance.

[0043] S2. Secondly, after the warp monofilament forms an opening, the weft yarn is pulled by the weft insertion mechanism 3 and the clamping mechanism 4 to weave the warp and weft monofilaments. The fabric structure can be plain or twill, with a width of 60-120 cm. After the warp and weft are interwoven, the monofilament has the function of intercepting sand and gravel.

[0044] Finally, S3, the sand barrier had a warp density of 30-80 strands / 10cm, and a weft density of 10-30 strands / 10cm and 30-60 strands / 10cm alternating between two sections. Sand barriers with different warp and weft densities correspond to different sand barrier requirements. To verify the effect of weft density on monofilament sand barriers, we used 0.2 mm diameter polylactic acid (85% by mass) monofilament sand barriers. The warp density was constant at 50 strands / 10cm, and the weft density was divided into two sections: 30 strands / 10cm and 50 strands / 10cm. The two density sections alternated every 10cm. The number of natural wrinkles per meter formed on the exposed sand surface of the two sand barriers is shown in Table 2: Table 2 Effect of weft density on the wrinkles of monofilament sand barrier

[0045] As can be seen from Table 2, under the alternating weft density scheme, the number of natural folds formed per meter of sand barrier is 3-4 times the number of folds formed in the constant weft density scheme. Moreover, due to the use of a structure with alternating weft density, the fold structure is formed spontaneously without the aid of special sand barrier construction equipment, which is beneficial to wind and sand fixation and has strong anti-lodging performance.

[0046] S4, the monofilaments that make up the sand barrier are composed of three parts: polylactic acid, calcium carbonate, and polycaprolactone or polybutylene terephthalate-adipate. The mass percentage of polycaprolactone or polybutylene terephthalate-adipate is 0-15%, and the mass percentage of calcium carbonate is 0-5%. The monofilament produced by this specific ratio has better material properties. Sand barriers were woven using polylactic acid monofilaments with a diameter of 0.22 mm, with a constant warp and weft density of 55 strands / 10 cm. The polylactic acid ratio was varied (70%-100%), and the monofilament modulus, bending length, and weaving efficiency of the sand barrier were tested. The data are shown in Table 3: Table 3 Effects of PLA ratio and monofilament modulus on sand barrier stiffness and loom efficiency

[0047] It can be seen from Table 3 that an increase in the proportion of polylactic acid will increase the monofilament modulus, increase the bending resistance of the sand barrier, and at the same time reduce the loom efficiency. However, choosing a polylactic acid proportion of 85% can not only obtain higher bending resistance, but also maintain the weaving efficiency at a high level.

[0048] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A rapier loom device for preparing a degradable monofilament net-type sand barrier, comprising a rapier loom body (1), a bracket (2) arranged in the middle of the rapier loom body (1), characterized in that: It also includes a weft insertion mechanism (3) arranged on the top of the bracket (2), and a clamping mechanism (4) arranged on the top of the weft insertion mechanism (3); The weft insertion mechanism (3) includes a shell (31) arranged on the top of the bracket (2), a double-layer cavity (32) opened in the shell, a clamping arm (33) arranged on both sides of the lower layer of the double-layer cavity (32), a pulling unit symmetrically arranged on the upper layer of the double-layer cavity (32), two ends of a tension spring (310) respectively fixedly connected to the rotary arm (38) and the upper layer of the double-layer cavity (32), a lower horizontal plate (34) arranged on the side of the bracket (2) close to the lower push rod (35), a lower push rod (35) arranged on the outside of the shell (31), a reciprocating horizontal plate (36) arranged on the side of the bracket (2) opposite to the lower push rod (35), and a weft joining unit arranged on the side of the bracket (2) away from the shell (31); The lower layer of the double-layer cavity (32) accommodates the clamping arm 1 (33), and the upper layer of the double-layer cavity (32) accommodates the pulling unit. The pulling unit drives the clamping arm 1 (33) to move. The lower horizontal plate (34) squeezes the pulling unit on the corresponding side. The reciprocating horizontal plate (36) squeezes the other pulling unit on the corresponding side. After the pulling unit is squeezed, it drives the corresponding clamping arm 1 (33) to move.

2. The rapier loom device for preparing a degradable monofilament net-type sand barrier according to claim 1, characterized in that: The pulling unit includes a support shaft (37) symmetrically arranged on the upper layer of the double-layer cavity (32), a rotary arm (38) arranged on the outside of the support shaft (37), a guide rail (39) arranged on one end of the rotary arm (38) close to the support shaft (37), the guide rail (39) is connected to the corresponding clamping arm in a limited sliding manner, and a tension spring (310) is arranged in the middle of the rotary arm (38).

3. The rapier loom device for preparing a degradable monofilament net-type sand barrier according to claim 2, characterized in that: The end of the rotary arm (38) away from the support shaft (37) is provided with two branches, and the two branches are at different heights, wherein the lower branch is at the same height as the lower transverse plate (34) and the lower push rod (35), and the thickness of the reciprocating transverse plate (36) is equal to the thickness of the rotary arm (38) on the corresponding side.

4. The rapier loom device for preparing a degradable monofilament net-type sand barrier according to claim 1, characterized in that: The weft joining unit includes a second shell (311) arranged on a side of the bracket (2) away from the first shell (31), the structure of the second shell (311) is symmetrical with the structure of the first shell (31), a second clamping arm (312) arranged on both sides of the lower layer of the double-layer cavity (32) of the second shell (311), another pulling unit arranged on the upper layer of the double-layer cavity (32) of the second shell (311), a torsion spring (313) sleeved on the top of the second clamping arm (312), and a second clamping arm (312) arranged on the upper layer of the double-layer cavity (32) of the second shell (311). The cross arm (314) is located at the top of the torsion spring (313), and both ends of the torsion spring (313) are fixedly connected to the cross arm (314) and the second clamping arm (312) respectively. An upper push rod (315) is provided on the side of the second housing (311) close to the corresponding pulling unit, and the second clamping arm (312) is fixedly connected to the second housing (311) on the side away from the upper push rod (315), and an upper cross plate (316) is provided on the end of the bracket (2) close to the upper push rod (315).

5. The rapier loom device for preparing a degradable monofilament net type sand barrier according to claim 4, characterized in that: The upper horizontal plate (316) and the upper push rod (315) have the same height, and the higher branch of the rotary arm (38) corresponding to the second housing (311) has the same height as the upper horizontal plate (316).

6. The rapier loom device for preparing a degradable monofilament net type sand barrier according to claim 1, characterized in that: The clamping mechanism (4) comprises a pressure plate (41) respectively arranged on the top of the clamping arm 1 (33) and the clamping arm 2 (312), a rotating block (42) arranged on the side where the two adjacent pressure plates (41) are close to each other, the rotating block (42) is rotatably connected to the pressure plate (41), a rubber plate (43) arranged on the side where the rotating block (42) is close to each other, and a short rod (44) arranged in the middle of the pressure plate (41) on the side closest to the lower horizontal plate (34).

7. The rapier loom device for preparing a degradable monofilament net-type sand barrier according to claim 6, characterized in that: The pressing plate (41) is elliptical, and the outer shape of the rotating block (42) is truncated cone.

8. A method for preparing a degradable monofilament net-type sand barrier, wherein the method comprises using the rapier loom device for preparing a degradable monofilament net-type sand barrier according to claim 1, wherein: The following steps are involved: First, select the monofilament with a diameter of 0.2-0.4mm, a strength of 2.5-3.5cN / dtex, an elongation at break of 25-35%, and a Young's modulus of 25-45cN / dtex; Secondly, after the warp monofilaments are formed into openings, the weft monofilaments are pulled by the weft insertion mechanism (3) and the clamping mechanism (4) to weave the warp and weft monofilaments into sand barriers. The fabric structure can be plain or twill, with a width of 60-120 cm. Finally, the sand barrier has a warp density of 30-80 strands / 10cm and a weft density of 10-30 strands / 10cm and 30-60 strands / 10cm alternatingly.

9. The method for preparing a degradable monofilament net-type sand barrier according to claim 8, characterized in that: The monofilaments constituting the sand barrier are composed of three parts: polylactic acid, calcium carbonate and polycaprolactone or polybutylene terephthalate-adipate, wherein the mass percentage of polycaprolactone or polybutylene terephthalate-adipate is 0-15%, and the mass percentage of calcium carbonate is 0-5%.

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