Rapier loom device and preparation method for biodegradable monofilament mesh sand barrier

Abstract

This invention relates to the field of textile fiber products technology, and discloses a rapier loom device and its preparation method for preparing biodegradable monofilament mesh sand barriers. The biodegradable monofilament mesh sand barrier preparation rapier loom device includes a rapier loom body, a support frame located in the middle of the rapier loom body, and a weft insertion mechanism located at the top of the support frame. By setting up the weft insertion mechanism, the stress-bearing area of ​​the monofilament weft yarn is increased when it is pulled, and the stress is dispersed, reducing the possibility of breakage due to excessive pressure on a single part. The preparation method of the biodegradable monofilament mesh sand barrier involves using polylactic acid monofilaments with a diameter of 0.2-0.4 mm in the sand barrier fabric, with alternating weft densities of 10-30 threads / 10cm and 30-60 threads / 10cm. The prepared mesh sand barrier fabric has high stiffness without stiffening treatment and is compostable. Furthermore, it can form natural folds during laying without relying on specially designed laying machinery, which is advantageous for desert ecological restoration applications.

Description

Technical Field

[0001] This invention relates to the field of textile fiber products technology, and in particular to a rapier loom device and its preparation method for preparing biodegradable monofilament mesh sand barriers. Background Technology

[0002] Sand barriers are a common technique for windbreak and sand fixation in arid and semi-arid regions. They slow down the speed of windblown sand through physical obstruction, thus achieving the effect of windbreak and sand fixation. Compared with traditional straw checkerboard or fence-type sand barriers, mesh sand barriers are more conducive to mechanized and large-scale construction. Currently, the warp and weft yarns of mesh sand barriers are mainly made of single-fiber yarns (such as cotton or viscose) or polyethylene monofilaments. Among these two materials, sand barriers made of short-fiber yarns are prone to collapsing and usually require stiffening, directly increasing the cost of sand barriers. Sand barriers made of polyethylene monofilaments are subject to degradation, which is environmentally unfriendly. Considering both the requirements for lodging resistance and ecological degradation, using coarse polylactic acid monofilaments (0.2 mm in diameter) to prepare mesh sand barriers is a feasible and advantageous solution.

[0003] From an application perspective, sand barrier woven fabrics need to have a wrinkled shape after being laid to improve wind resistance and lodging resistance. Traditional woven sand barriers (with constant warp and weft density) cannot automatically form wrinkles and require the assistance of sand-fixing machinery, which places complex demands on sand barrier laying machinery. From a fabric perspective, intermittently changing the weft density can promote wrinkle formation, thereby reducing the requirements for sand barrier installation machinery. This type of mesh sand barrier can automatically form wrinkles after being laid, possessing natural lodging resistance. Currently, no such sand barrier woven fabric design has been seen in the industry. Due to the inherent brittleness of polylactic acid polymers, coarse polylactic acid monofilaments (0.2mm in diameter) are usually quite brittle and stiff, posing challenges to the weaving (machine weaving) process. The main problems include long downtime and low weaving efficiency, thus requiring improvements to the rapier loom device. The rapier head of a conventional rapier loom fixes the weft yarn through a precision mechanical or pneumatic clamping mechanism, the design of which directly affects the reliability of weft insertion and weaving efficiency. Currently, over 80% of rapier looms use elastic clamping strips to hold the weft yarn. These clamping strips are made of high-carbon steel or titanium alloy and generate clamping force (usually adjustable from 0.5-3N) through a pre-compression spring. The opening and closing sequence of the clamping strips is controlled by a trigger cam, synchronized with the loom's main shaft. To improve clamping force, the clamping surface is often designed with fine teeth (0.2-0.5mm tooth pitch) to enhance friction. When the weft yarn is a relatively soft short-fiber yarn, the clamping control effect of the clamping strips is generally good. However, when the weft yarn is a monofilament, especially a thick and brittle polylactic acid monofilament, insufficient effective clamping area can occur. In this case, the weft monofilament is prone to stress concentration during high-speed movement, and the impact and bending stress experienced by the weft monofilament during weft splicing are also greater, leading to weft yarn breakage or slippage. Therefore, a dedicated rapier clamping device needs to be designed for thick and stiff monofilament weft yarns. On the one hand, it solves the problem of weft monofilament breakage caused by low effective clamping area and high local stress. On the other hand, it solves the problem of excessive tension fluctuation of weft monofilament during rapier head junction and weaving process, which causes weft yarn breakage or failure of photoelectric weft detection device, leading to shutdown.

[0004] Rapier looms play a crucial role in the fabrication of sand barriers. Utilizing the reciprocating motion of the rapier, they precisely guide the weft yarns into the weave, where they work together with the warp yarns to form a tightly woven fabric. This type of loom is flexible in operation, allowing for adjustments to fabric density and width as needed, ensuring sufficient strength and stability for the sand barriers. During the weaving process, the high efficiency of rapier looms significantly improves production efficiency and shortens the manufacturing cycle of sand barriers. Through the application of rapier looms, the quality and performance of sand barriers are significantly enhanced, providing strong support for desertification control projects.

[0005] Rapier looms are widely used in the textile industry, but due to limitations in their structure and working principle, they often present some significant problems. In the weft feeding stage, the rapier rapidly reciprocates to feed the weft yarn from the feed side to the receiving side. Because the contact area between the rapier and the weft yarn is limited, the weft yarn experiences significant friction and tension during high-speed movement, easily leading to localized stress concentration and weft yarn breakage. Simultaneously, the rapier needs to overcome resistance during weft feeding, further increasing the stress on the weft yarn. In the weft splicing stage, the splicing rapier faces similar problems. Furthermore, due to the small contact area between the feed and splicing rapiers and the weft yarn, the weft yarn experiences greater impact and bending stress during splicing, again making it prone to breakage. Summary of the Invention

[0006] In view of the problem that the existing rapier loom is prone to weft yarn breakage during the weft insertion process, a rapier loom device for preparing biodegradable monofilament mesh sand barriers is proposed.

[0007] The purpose is to reduce the probability of yarn breakage by increasing the contact area between the rapier loom and the weft yarn end, and by 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 biodegradable monofilament mesh sand barrier, including a rapier loom body, a support set in the middle of the rapier loom body, a weft insertion mechanism set at the top of the support, and a clamping mechanism set at the top of the weft insertion mechanism;

[0009] The weft insertion mechanism includes an outer shell at the top of the support, a double-layer cavity inside the outer shell, clamping arms on both sides of the lower layer of the double-layer cavity, traction units symmetrically arranged on the upper layer of the double-layer cavity, two ends of a tension spring fixedly connected to the swivel arm and the upper layer of the double-layer cavity respectively, a lower horizontal plate on the side of the support near the lower push rod, a lower push rod on the outside of the outer shell, a reciprocating horizontal plate on the support opposite to the lower push rod, and a weft insertion unit on the side of the support away from the outer shell.

[0010] The lower layer of the double-layer cavity accommodates clamping arm one, and the upper layer of the double-layer cavity accommodates traction unit. The traction unit drives clamping arm one to move. The lower horizontal plate squeezes the traction unit on the corresponding side, and the reciprocating horizontal plate squeezes the other traction unit on the corresponding side. After being squeezed, the traction unit drives the corresponding clamping arm one to move.

[0011] Furthermore, the traction unit includes a support shaft symmetrically arranged on the upper layer of the double-layer cavity, a rotating arm arranged on the outside of the support shaft, a guide rail arranged on the rotating arm near one end of the support shaft, the guide rail being slidably connected to the corresponding clamping arm, and a tension spring arranged in the middle of the rotating arm.

[0012] Furthermore, the end of the rotary arm away from the support shaft is provided with two branches, and the two branches are at different heights. The lower branch is at the same height as the lower horizontal plate and the lower push rod, and the thickness of the reciprocating horizontal plate is equal to the thickness of the corresponding side of the rotary arm.

[0013] Furthermore, the weft insertion unit includes a second outer shell disposed on the side of the support away from the first outer shell, the structure of the second outer shell being symmetrical to that of the first outer shell; two clamping arms disposed on both sides of the lower layer of the double-layer cavity of the second outer shell; another traction unit disposed on the upper layer of the double-layer cavity of the second outer shell; a torsion spring sleeved on the top of the clamping arm; a cross arm disposed on the top of the torsion spring, the two ends of the torsion spring being fixedly connected to the cross arm and the clamping arm respectively; an upper push rod disposed on the side of the second outer shell near the corresponding traction unit; the clamping arm on the side away from the upper push rod being fixedly connected to the second outer shell; and an upper cross plate disposed on the support near the upper push rod.

[0014] Furthermore, the upper horizontal plate and the upper push rod are at the same height, and the higher branch of the rotating arm corresponding to the second outer casing is at the same height as the upper horizontal plate.

[0015] Furthermore, the clamping mechanism includes pressure plates respectively disposed on the top of clamping arm one and clamping arm two, a rotating block disposed on the side of two adjacent pressure plates that are close to each other, the rotating block being rotatably connected to the pressure plate, a rubber plate disposed on the side of the rotating block that is close to each other, and a short rod disposed in the middle of the pressure plate closest to the lower horizontal plate.

[0016] Furthermore, the pressure plate is elliptical, and the rotating block is frustum-shaped.

[0017] Another objective of this invention is to provide a method for preparing a biodegradable monofilament mesh sand barrier, the purpose of which is to prepare a sand barrier with the function of intercepting sand and gravel using a machine weaving method.

[0018] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a biodegradable monofilament mesh sand barrier, comprising the following steps:

[0019] 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.

[0020] Secondly, after the single filament warp is threaded, the weft yarn is pulled by the weft insertion mechanism and the clamping mechanism to weave the warp and weft single filaments into a barrier. The fabric structure can be plain weave or twill weave, and the width is 60-120cm.

[0021] Finally, the sand barriers are composed of alternating densities of 30-80 roots / 10cm in the meridional direction and 10-30 roots / 10cm and 30-60 roots / 10cm in the latitudinal direction.

[0022] Furthermore, the monofilaments that make up the sand barrier are composed of three parts: polylactic acid, calcium carbonate, and polycaprolactone or polybutylene terephthalate, wherein the mass percentage of polycaprolactone or polybutylene terephthalate is 0-15%, and the mass percentage of calcium carbonate is 0-5%.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. By setting up a weft insertion mechanism, the weft yarn is fixed by squeezing it with two parallel surfaces during the weft yarn feeding process. This applies pressure evenly to the weft yarn, keeping it stable. Compared with the traditional method of fixing the weft yarn with clamping strips, the weft insertion mechanism allows for effective contact between the weft yarn and the clamping components, increasing the force-bearing area. Clamping strips may cause the weft yarn to break due to concentrated force during movement. Now, with the increased force-bearing area, the stress is dispersed, reducing the possibility of excessive pressure on a single part. In this way, the weft yarn can pass through the warp yarn more smoothly during the weft feeding process, avoiding yarn breakage caused by excessive local force or severe vibration. This design of the weft feeding mechanism ensures the continuity and integrity of the weft yarn during the weaving process, enabling the loom to work continuously and stably, improving weaving efficiency and product quality.

[0025] 2. By setting up a weft splicing unit, when the weft yarn is fed to the splicing position, the weft splicing unit also contacts the weft yarn through the compression of two parallel surfaces. This avoids the excessive pulling or bending of the weft yarn at the moment of splicing caused by traditional yarn clamping plates. The weft splicing unit ensures that the weft yarn is subjected to uniform force during the splicing process, preventing stress concentration on a certain point of the weft yarn. In this way, the weft yarn will not break due to sudden excessive stress at a certain point. The weft splicing unit ensures that the process of weft yarn from weft feeding to weaving into the fabric is smooth and continuous, maintaining the integrity of the weft yarn.

[0026] 3. By setting up a clamping mechanism, when two corresponding rotating blocks clamp the weft yarn and begin to move, the weft yarn will generate a pulling force on the rotating blocks. The rotating blocks under tension will rotate accordingly. This rotational action adjusts the shape of the weft yarn, keeping the clamped part of the weft yarn and the unclamped part of the weft yarn in a horizontal state. Compared with the traditional method of clamping the yarn end with a clamping plate by a rapier, the clamping mechanism reduces the bending amplitude of the weft yarn in the clamping area. The potentially large bending is alleviated by the rotation of the rotating blocks, avoiding excessive stress on the weft yarn at the bending point. The setting of the clamping mechanism enables the loom to adapt to the weaving of high modulus monofilament weft yarn, making the weft yarn smoother during movement and reducing the risk of breakage. The design of the rotating blocks allows the weft yarn to maintain a good state during the weaving process.

[0027] 4. Using coarse polylactic acid monofilaments with a diameter greater than 0.2 mm to prepare sand barrier woven fabric: Compared with polyethylene, polylactic acid raw material has the advantage of compostability and biodegradability, which solves the concern about the degradation of sand barriers; the advantage of coarse diameter monofilaments compared with short fiber yarns is that they have high modulus and high stiffness, so the woven fabric of sand barriers has inherent stiffness. No stiffening treatment is required, and it can be used directly for windbreak and sand fixation.

[0028] 5. Variable weft density woven fabric design: Under the condition of constant warp density, the weft density is varied, alternating between two sections: 10-30 threads / 10cm and 30-60 threads / 10cm. After laying, this sand barrier woven fabric with alternating weft density forms wrinkles more easily than sand barrier woven fabric with a single weft density, which is more beneficial for windbreak and sand fixation. In addition, this sand barrier with varying weft density does not require specially designed laying machinery to form natural wrinkles during the laying process, saving construction costs. Attached Figure Description

[0029] Figure 1 This is a three-dimensional structural diagram of the rapier loom of the present invention;

[0030] Figure 2 This is a schematic diagram of the overall structure of the support frame of the rapier loom of the present invention;

[0031] Figure 3 This is a schematic diagram showing the connection between the support frame and the weft insertion mechanism of the rapier loom of the present invention;

[0032] Figure 4 This is a schematic diagram showing the connection between the support frame, the lower cross plate, and the reciprocating cross plate of the rapier loom of the present invention;

[0033] Figure 5 This is a schematic diagram showing the connection between the outer casing of the rapier loom of the present invention and the lower push rod;

[0034] Figure 6 This is a schematic diagram showing the connection between the clamping arm 1 and the outer casing 1 of the rapier loom of the present invention;

[0035] Figure 7 This is a schematic diagram showing the connection between the tensioning unit and the outer casing of the rapier loom of the present invention.

[0036] Figure 8 This is a schematic diagram of the overall structure of the drawing unit of the rapier loom of the present invention;

[0037] Figure 9 This is a schematic diagram of the overall structure of the weft insertion unit of the rapier loom of the present invention;

[0038] Figure 10 This is a schematic diagram showing the connection between the outer shell 2 and the clamping arm 2 of the rapier loom of the present invention;

[0039] Figure 11This is a schematic diagram of the internal structure of the outer shell of the rapier loom of the present invention;

[0040] Figure 12 This is a schematic diagram showing the connection between the cross arm and the clamping arm of the rapier loom of the present invention.

[0041] Figure 13 This is a schematic diagram showing the connection between the pressure plate and the short rod of the rapier loom of the present invention.

[0042] In the picture:

[0043] 1. Rapier loom body; 2. Support frame; 3. Weft insertion mechanism; 4. Clamping mechanism; 31. Outer shell one; 32. Double-layer cavity; 33. Clamping arm one; 34. Lower cross plate; 35. Lower push rod; 36. Reciprocating cross plate; 37. Support shaft; 38. Rotary arm; 39. Guide rail; 310. Tension spring; 311. Outer shell two; 312. Clamping arm two; 313. Torsion spring; 314. Cross arm; 315. Upper push rod; 316. Upper cross plate; 41. Pressure plate; 42. Rotating block; 43. Rubber plate; 44. Short rod. Detailed Implementation

[0044] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0045] Example 1, referring to Figures 1-13 This invention provides a first embodiment of a rapier loom device for preparing a biodegradable monofilament mesh sand barrier. The device includes a rapier loom body 1, a support 2 fixedly connected to the middle of the rapier loom body 1, a weft insertion mechanism 3 mounted on top of the support 2, and a clamping mechanism 4 mounted on top of the weft insertion mechanism 3. The weft insertion mechanism 3 includes a housing 31 fixedly connected to the top of the support 2, a double-layer cavity 32 opened inside the housing, clamping arms 33 slidably connected to both sides of the lower layer of the double-layer cavity 32, a traction unit symmetrically assembled on the upper layer of the double-layer cavity 32, and tension springs 310 with their ends connected to the rotating arm 38 and the upper layer of the double-layer cavity 32, respectively. The double-layer cavity 32 is fixedly connected to the following components: a lower horizontal plate 34 fixedly connected to the side of the bracket 2 near the lower push rod 35; a lower push rod 35 fixedly connected to the outside of the outer shell 31; a reciprocating horizontal plate 36 fixedly connected to the bracket 2 on the opposite side of the lower push rod 35; and a weft insertion unit assembled on the side of the bracket 2 away from the outer shell 31. The lower layer of the double-layer cavity 32 accommodates a clamping arm 33, and the upper layer of the double-layer cavity 32 accommodates a traction unit. The traction unit drives the clamping arm 33 to move. The lower horizontal plate 34 presses the traction unit on the corresponding side, and the reciprocating horizontal plate 36 presses the other traction unit on the corresponding side. After being compressed, the traction unit drives the corresponding clamping arm 33 to move.

[0046] Specifically, each end of the support 2 is provided with a sword rod. The two sword rods push the outer shell 31 and the outer shell 311 to move. When the outer shell 31 moves, it drives the other internal components connected to it to move together. The lower layer of the double cavity 32 accommodates the sliding of the clamping arm 33 inside, and the upper layer of the double cavity 32 accommodates the movement of the traction unit inside. The lower horizontal plate 34 squeezes the rotating arm 38, forcing the rotating arm 38 to rotate. After the outer shell 31 and the outer shell 311 approach each other to the maximum stroke, the lower push rod 35 pushes the corresponding rotating arm 38 on the same side of the outer shell 311. The lower horizontal plate 34 squeezes the corresponding rotating arm 38 on the same side that moves with the outer shell 31. The reciprocating horizontal bar squeezes the corresponding rotating arm 38 on the same side that moves with the outer shell 31, causing it to rotate. When the outer shell 31 drives the rotating arms 38 on the corresponding two traction units to move and reset, the rotating arm 38 on the side closer to the reciprocating horizontal plate 36 will be pushed by it during the movement and reset process, thus rotating.

[0047] Reference Figure 7 The traction unit includes a support shaft 37 symmetrically fixedly connected to the upper layer of the double-layer cavity 32, a rotating arm 38 rotatably connected to the outside of the support shaft 37, a guide rail 39 fixedly connected to one end of the rotating arm 38 near the support shaft 37, the guide rail 39 being slidably connected to the corresponding clamping arm, and a tension spring 310 fixedly connected to the middle of the rotating arm 38.

[0048] Specifically, the pivot 37 constrains the position of the rotating arm 38, so that it can only rotate around the pivot 37. When the rotating arm 38 is subjected to external pressure, it will rotate. The guide rail 39 rotates together with the rotating 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 rotating arm 38, so that the rotating arm 38 remains in contact with the outer shell 31.

[0049] 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. The lower branch is at the same height as the lower horizontal plate 34 and the lower push rod 35. The thickness of the reciprocating horizontal plate 36 is equal to the thickness of the corresponding side rotary arm 38.

[0050] Specifically, as the rotating arm 38 moves back and forth with the outer shell 31, the two branches will reverse their direction after being squeezed by the upper horizontal plate 316 or the lower horizontal plate 34. The upper horizontal plate 316 and the lower horizontal plate 34 only push the branches of the rotating arm 38 that are on the same side and at the same height as themselves.

[0051] Reference Figures 1-12The weft insertion unit includes a second outer shell 311 fixedly connected to the side of the support 2 away from the first outer shell 31. The structure of the second outer shell 311 is symmetrical to that of the first outer shell 31. The clamping arms 312 are slidably connected to both sides of the lower layer of the double cavity 32 of the second outer shell 311. Another pulling unit is assembled on the upper layer of the double cavity 32 of the second outer shell 311. A torsion spring 313 is sleeved on the top of the clamping arm 312. A cross arm 314 is fixedly connected to the top of the torsion spring 313. The two ends of the torsion spring 313 are fixedly connected to the cross arm 314 and the clamping arm 312 respectively. An upper push rod 315 is fixedly connected to the side of the second outer shell 311 near the corresponding pulling unit. The clamping arm 312 on the side away from the upper push rod 315 is fixedly connected to the second outer shell 311. An upper cross plate 316 is fixedly connected to the end of the support 2 near the upper push rod 315.

[0052] Specifically, the structure of the second outer shell 311 is symmetrical to that of the first outer shell 31. Of the two clamping arms 312, the clamping arm 312 away from the upper push rod 315 is fixedly connected to the second outer shell 311. The other clamping arm 312 is driven by the pulling unit corresponding to the second outer shell 311. The second outer shell 311 moves back and forth with the corresponding sword rod on the bracket 2, and moves the clamping arm 312 together with it. The clamping arm 312 moves the horizontal arm 314 together with it. The push rod pushes the passing rotating arm 38, and the upper horizontal plate 316 also pushes the passing rotating arm 38.

[0053] Reference Figure 9 The upper horizontal plate 316 and the upper push rod 315 have the same height, and the higher branch of the rotating arm 38 corresponding to the outer shell 311 has the same height as the upper horizontal plate 316.

[0054] Specifically, the upper horizontal plate 316 presses against the corresponding rotating arm 38 on the same side that moves with the outer shell 2 311, and the upper horizontal plate 316 presses against the corresponding rotating arm 38 on the same side that moves with the outer shell 1 31.

[0055] Example 2, refer to Figures 1-13 The clamping mechanism 4 includes a pressure plate 41 fixedly connected to the top of the clamping arm 33 and the clamping arm 312 respectively, a rotating block 42 rotatably connected to the side of the two adjacent pressure plates 41 that are close to each other, the rotating block 42 being rotatably connected to the pressure plate 41, a rubber plate 43 fixedly connected to the side of the rotating block 42 that is close to each other, and a short rod 44 fixedly connected to the middle of the pressure plate 41 on the side closest to the lower horizontal plate 34.

[0056] Specifically, the pressure plate 41 on the horizontal arm 314 is slightly higher than the pressure plate 41 on the clamping arm 33. As the horizontal arm 314 and the clamping arm 33 approach each other, the pressure plate 41 on the horizontal arm 314 will squeeze the pressure plate 41 on the corresponding clamping arm 33 on the same side, thereby causing the horizontal arm 314 to rotate upward with the connection point with the clamping arm 312 as the center. After the pressure plates 41 corresponding to the clamping arm 33 and the rotating arm 38 are misaligned, the horizontal arm 314 returns to its original position under the action of the torsion spring 313. When the pulling unit corresponding to the clamping arm 312 approaches each other, it drives the corresponding clamping block and rubber plate 43 to approach each other until the two rubber plates 43 abut against each other, flexibly clamping the weft yarn. As the clamping arm 33 moves 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, it will pull the weft yarn to a near-horizontal state, making it easier to be clamped.

[0057] Reference Figure 13 The pressure plate 41 is elliptical, and the rotating block 42 is truncated cone-shaped.

[0058] Specifically, since the pressure plate 41 is elliptical, when the distal ends of the pressure plates 41, which are on the same plane and have different circular heights, are pressed against each other, the two pressure plates 41 will be misaligned. The rotating block 42, through the outer circle of the cone-shaped frustum, causes the weft yarn to move towards the side with the adhesive plate 43 under the guidance of the cone after contacting the side of the rotating block 42. The rest of the structure is the same as that of Embodiment 1.

[0059] Based on embodiments 1-2, the working principle of this invention is as follows: During weft insertion, the support 2 drives the outer shell 31 and the second outer shell 311 to reciprocate by moving closer to each other and resetting, driven by the rapier. As the outer shell 31 moves towards the outer shell, it drives the two clamping arms 33 and the corresponding two traction units to move. The rotating arm 38 on the side of the outer shell 31 closest to the reciprocating horizontal plate 36 will be pushed when it passes the reciprocating horizontal plate 36, thereby generating rotation. Under the action of the corresponding tension spring 310, it points to another position. At the same time as the rotation, it drives the corresponding clamping arm 33 towards the other clamping arm 311. 3. Move and drive the corresponding rotating block 42 to move until it contacts the rotating block 42 on another 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, so that the weft yarn moves together with the outer shell 31. After the weft yarn is pulled and tightened, the reaction force of the pull is transmitted to the two corresponding rotating blocks 42. The two rotating blocks 42 rotate so that the clamped part of the weft yarn and the unclamped part are kept in a nearly straight state, so as to avoid the weft yarn from breaking due to excessive bending.

[0060] When outer shell 1 31 and outer shell 2 311 are close to each other by a certain distance, the pressure plates 41 corresponding to clamping arm 1 33 and clamping arm 2 312 squeeze each other, driving the horizontal arm 314 to rise, so that the pressure plates 41 corresponding to clamping arm 1 33 and clamping arm 2 312 cross each other. At this time, the lower push rod 35 pushes the rotating arm 38 corresponding to outer shell 2 311, so that it drives the corresponding clamping arm 2 312 and the horizontal arm 314 to move. The horizontal arm 314 drives the corresponding rotating block 42 to move together. After the rotating blocks 42 of the two horizontal arms 314 come into contact, the weft yarn is clamped. During this process, the upper push rod 315 pushes the rotating arm 38 on the same side of outer shell 1 31, so that it drives the corresponding clamping arm 1 33 away from the other clamping arm, releasing the clamping of the weft yarn, thus realizing the handover of weft feeding and weft splicing. When the handover is completed, outer shell 1 31 and outer shell 2 311 move away from each other, and the weft splicing unit drives the weft yarn to the weft splicing side of the loom.

[0061] During the reset process of outer shell 1 31, the reciprocating horizontal plate 36 pushes the corresponding swivel arm 38, driving the corresponding clamping arm to reset. The lower horizontal plate 34 pushes the corresponding swivel arm 38 on the same side of outer shell 1 31 to reset it. During the reset process of outer shell 2 311, the corresponding swivel arm 38 is pushed by the upper horizontal plate 316 and thus resets, ready for the next weft insertion.

[0062] Example 3, referring to Figures 1-13 The third embodiment of the present invention provides a method for preparing a biodegradable monofilament mesh sand barrier, comprising the following steps:

[0063] S1. First, select monofilaments with a diameter of 0.2-0.4 mm, a strength of 2.5-3.5 cN / dtex, a breaking elongation of 25-35%, and a Young's modulus of 25-45 cN / dtex. Use polylactic acid monofilaments (containing 90% polylactic acid and 10% polybutylene terephthalate) and polylactic acid staple fiber yarns of similar thickness to weave sand barriers. The warp and weft densities are both 50 threads / 10cm. Test the bending length of the sand barrier fabric according to GB / T18318-2001, and test 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.

[0064] Table 1. Differences between polylactic acid monofilament and polylactic acid yarn mesh sand barriers

[0065]

[0066] As shown in Table 1, when the yarn diameter is the same, the bending length of the monofilament sand barrier is better than that of the mesh sand barrier with yarn structure. In addition, the increase rate of the vertical projection area of ​​the mesh sand barrier with monofilament structure after encountering strong wind is also significantly lower than that of the mesh sand barrier with yarn structure. The above results indicate that the monofilament sand barrier has a significant advantage in stiffness.

[0067] 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 weave or twill weave, with a width of 60-120cm. After the monofilaments are interwoven with the warp and weft, they have the function of intercepting sand and gravel.

[0068] S3. Finally, the sand barriers were constructed with alternating warp and weft densities of 30-80 threads / 10cm and 10-30 threads / 10cm and 30-60 threads / 10cm, respectively. Different warp and weft densities corresponded to different sand-blocking requirements. To verify the impact of weft density on monofilament sand barriers, sand barriers were woven using polylactic acid (85% by mass) monofilaments with a diameter of 0.2 mm. The warp density was constant at 50 threads / 10 cm, while the weft densities were of two types: 30 threads / 10 cm and 50 threads / 10 cm, alternating every 10 cm. The number of natural folds per meter formed on the exposed sand surface of both types of sand barriers was measured, as shown in Table 2.

[0069] Table 2. Influence of weft density on the folds of monofilament sand barriers

[0070]

[0071] As shown in Table 2, under the alternating latitude density scheme, the number of natural folds formed per meter of sand barrier is 3-4 times that under the constant latitude density scheme. Furthermore, due to the use of an alternating latitude density structure, the fold structure is formed spontaneously without the aid of special sand barrier construction equipment, which is beneficial for windbreak and sand fixation and has strong anti-collapse performance.

[0072] S4, the monofilaments that make up the sand barrier are composed of three parts: polylactic acid, calcium carbonate, and polycaprolactone or polybutylene terephthalate. The mass percentage of polycaprolactone or polybutylene terephthalate is 0-15%, and the mass percentage of calcium carbonate is 0-5%. Monofilaments made with a specific ratio have better material properties. Sand barriers were woven using 0.22 mm diameter polylactic acid monofilaments 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 of the sand barrier, and weaving efficiency were tested. The data are shown in Table 3.

[0073] Table 3. Effects of polylactic acid ratio and monofilament modulus on sand barrier stiffness and loom efficiency.

[0074]

[0075] As can be seen from Table 3, increasing the polylactic acid (PLA) ratio will increase the monofilament modulus and the bending resistance of the sand barrier, but at the same time reduce the loom efficiency. However, choosing an 85% PLA ratio can not only obtain higher bending resistance, but also maintain the weaving efficiency at a high level.

[0076] 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 it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A rapier loom device for preparing biodegradable monofilament sand barriers, comprising a rapier loom body (1) and a support (2) disposed in the middle of the rapier loom body (1), characterized in that, It also includes a weft insertion mechanism (3) set on the top of the support (2), and a clamping mechanism (4) set on the top of the weft insertion mechanism (3). The weft insertion mechanism (3) includes an outer shell (31) set on the top of the support (2), a double cavity (32) opened inside the outer shell, clamping arms (33) set on both sides of the lower layer of the double cavity (32), a traction unit symmetrically set on the upper layer of the double cavity (32), the two ends of the tension spring (310) being fixedly connected to the swivel arm (38) and the upper layer of the double cavity (32) respectively, a lower horizontal plate (34) set on the side of the support (2) near the lower push rod (35), a lower push rod (35) set on the outside of the outer shell (31), a reciprocating horizontal plate (36) set on the side of the support (2) opposite to the lower push rod (35), and a weft insertion unit set on the side of the support (2) away from the outer shell (31). The lower layer of the double-layer cavity (32) accommodates clamping arm one (33), and the upper layer of the double-layer cavity (32) accommodates traction unit. The traction unit drives clamping arm one (33) to move. The lower horizontal plate (34) squeezes the traction unit on the corresponding side, and the reciprocating horizontal plate (36) squeezes the other traction unit on the corresponding side. After being squeezed, the traction unit drives the corresponding clamping arm one (33) to move. The traction unit includes a support shaft (37) symmetrically arranged on the upper layer of the double-layer cavity (32), a rotating arm (38) arranged on the outside of the support shaft (37), a guide rail (39) arranged on one end of the rotating arm (38) near the support shaft (37), the guide rail (39) being slidably connected to the corresponding clamping arm, and a tension spring (310) arranged in the middle of the rotating arm (38). 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. The lower branch is at the same height as the lower horizontal plate (34) and the lower push rod (35). The thickness of the reciprocating horizontal plate (36) is equal to the thickness of the corresponding side rotary arm (38). The weft insertion unit includes a second outer shell (311) disposed on the side of the support (2) away from the first outer shell (31). The structure of the second outer shell (311) is symmetrical to that of the first outer shell (31). It also includes two clamping arms (312) disposed on both sides of the lower layer of the double-layer cavity (32) of the second outer shell (311), another traction unit disposed on the upper layer of the double-layer cavity (32) of the second outer shell (311), and a torsion spring (313) sleeved on the top of the clamping arm (312). The top of the torsion spring (313) has a horizontal arm (314), the two ends of the torsion spring (313) are fixedly connected to the horizontal arm (314) and the clamping arm (312) respectively, the upper push rod (315) is set on the side of the outer shell (311) near the corresponding traction unit, the clamping arm (312) on the side away from the upper push rod (315) is fixedly connected to the outer shell (311), and the upper horizontal plate (316) is set on the bracket (2) near the upper push rod (315). The clamping mechanism (4) includes a pressure plate (41) respectively disposed on the top of the first clamping arm (33) and the second clamping arm (312), a rotating block (42) disposed on the side of the two adjacent pressure plates (41) that are close to each other, the rotating block (42) being rotatably connected to the pressure plate (41), a rubber plate (43) disposed on the side of the rotating block (42) that is close to each other, and a short rod (44) disposed in the middle of the pressure plate (41) closest to the lower horizontal plate (34).

2. The rapier loom device for preparing biodegradable monofilament mesh sand barriers according to claim 1, characterized in that, The upper horizontal plate (316) and the upper push rod (315) are at the same height, and the higher branch of the rotating arm (38) corresponding to the outer shell (311) is at the same height as the upper horizontal plate (316).

3. The rapier loom device for preparing biodegradable monofilament mesh sand barriers according to claim 1, characterized in that, The pressure plate (41) is elliptical, and the rotating block (42) is frustum-shaped.

4. A method for preparing a biodegradable monofilament mesh sand barrier, wherein the preparation process uses the rapier loom device for preparing a biodegradable monofilament mesh sand barrier as described in claim 1, characterized in that... Includes the following steps: 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. Secondly, after the warp monofilament forms an opening, the weft monofilament is pulled by the weft insertion mechanism (3) and the clamping mechanism (4) to weave the warp and weft monofilaments into a sand barrier. The fabric structure can be plain weave or twill weave, and the width is 60-120cm. Finally, the sand barriers are composed of alternating densities of 30-80 roots / 10cm in the meridional direction and 10-30 roots / 10cm and 30-60 roots / 10cm in the latitudinal direction.

5. The method for preparing a biodegradable monofilament mesh sand barrier according to claim 4, characterized in that, The monofilaments that make up the sand barrier are composed of three parts: polylactic acid, calcium carbonate, and polycaprolactone or polybutylene terephthalate, wherein the mass percentage of polycaprolactone or polybutylene terephthalate is 0-15%, and the mass percentage of calcium carbonate is 0-5%.

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