Degradable jute fiber nonwoven fabric for making high-grade shopping bags and method for producing the same

Abstract

The application discloses a degradable jute fiber non-woven fabric for manufacturing high-grade hand shopping bags, which is made of jute fibers, bi-component sheath-core structure polylactic acid fibers and cotton fibers, and the weight parts of the jute fibers, the bi-component sheath-core structure polylactic acid fibers and the cotton fibers are 40-60, 30-33 and 36-40 respectively. The application further discloses a method for producing the jute fiber non-woven fabric. The method can overcome the defects of the prior art and process the non-woven fabric which can be used for manufacturing high-grade hand shopping bags.

Description

Technical Field

[0001] This invention relates to a jute fabric, and more particularly to a biodegradable jute fiber nonwoven fabric for making high-end shopping bags; it also relates to a method for producing the jute fiber nonwoven fabric. Background Technology

[0002] Shopping bags are essential items in people's daily lives.

[0003] Single-use plastic bags are commonly used as shopping bags because they are inexpensive and convenient. However, because these plastic bags are generally difficult to degrade, they cause serious environmental pollution.

[0004] With the growing need for environmental protection, there is now a call to abandon plastic bags and switch to cloth bags. However, if shopping bags are made of pure cotton or pure jute fabric, the price is too high, making it difficult to promote their use.

[0005] In the search for a suitable fabric to replace disposable plastic bags for shopping bags—one that is cheaper than existing pure cotton or jute fabrics, easier to promote, and environmentally friendly—people have noticed biodegradable nonwoven materials, such as representative polylactic acid (PLA) and polybutylene terephthalate (PBAT). However, these materials are still very expensive, with raw material costs ranging from 30,000 to 50,000 yuan per ton. Currently, most fully biodegradable nonwoven shopping bags on the market are of this type, with a fabric weight of 70-80 grams per square meter and a selling price of over 1 yuan per bag. This price is still far higher than existing blow-molded bags, making widespread adoption difficult.

[0006] Jute fiber resources are abundant, with a global annual output exceeding 5 million tons. Jute fiber products have a long history of use and offer both environmental and cost advantages, priced at only around 5,000 yuan per ton. Therefore, spraying PLA and PBAT onto the surface of jute fiber products or fusion-coating PLA and PBAT films can reduce raw material costs while retaining the advantages of both jute fiber and PLA and PBAT. However, the unique texture of jute fiber is masked, making it unsuitable for producing high-end shopping bags.

[0007] If jute fiber can be combined with biodegradable polylactic acid (PLA) and PBAT fibers and processed into nonwoven fabric using modern nonwoven technology, the unique texture of jute fiber can be brought out, making it suitable for producing high-end shopping bags. Moreover, it can significantly reduce raw material costs, allowing the selling price to be below 1 yuan per bag, thus creating conditions for its widespread use.

[0008] However, in the existing technology, jute fiber combined with biodegradable polylactic acid (PLA) and PBAT fibers to process nonwoven fabrics has low seam strength. Some of these fabrics cannot be sewn together or have handles attached, making them unsuitable for use in making shopping bags. Instead, they are made by hand sewing, which would increase the cost several times over.

[0009] To develop a nonwoven fabric that combines jute and polylactic acid fibers for high-end shopping bags, the applicant invested significant research and development efforts. Extensive experiments and in-depth analyses were conducted on the composition and dosage of raw materials, as well as the steps and conditions of the production process. This resulted in a successful production of a biodegradable jute fiber nonwoven fabric suitable for high-end shopping bags. This biodegradable jute fiber nonwoven fabric overcomes the shortcomings of existing technologies, exhibiting excellent seam strength, reliable handle bonding, and the ability to support over 8 kg in the finished shopping bag. It possesses the unique texture of jute fiber and offers both environmental and cost advantages, with a selling price of approximately 0.7 yuan per bag. To protect this technological innovation, this patent application is filed for the biodegradable jute fiber nonwoven fabric for making shopping bags and its production method. Summary of the Invention

[0010] The purpose of this invention is to provide a biodegradable jute fiber nonwoven fabric for making high-end shopping bags, and also to provide a method for producing the jute fiber nonwoven fabric.

[0011] To address the aforementioned technical problems, the present invention provides a biodegradable jute fiber nonwoven fabric for manufacturing high-end shopping bags. The jute fiber nonwoven fabric is made of jute fiber, bicomponent core-sheath structure polylactic acid fiber, and cotton fiber, with weight proportions of 40-60, 30-33, and 36-40, respectively. The jute fiber is uniformly mixed with the bicomponent core-sheath structure polylactic acid fiber and cotton fiber, and then carded into a single-layer fiber web with a basis weight of 10-20 g / m². This web is then stacked in 4-6 layers to form a multi-layer composite web, and finally subjected to four needle-punching processes to entangle the fibers in the multi-layer composite web. Finally, the film is rolled online at a speed of 3-5 m / min using double hot rollers at 155-158℃, forming a film while the bicomponent polylactic acid fiber sheath is molten. After exiting the rollers, the film is immediately cooled and solidified to form a mesh structure. The jute fiber has an average count of over 900 metric counts and an average fiber length of 3-3.5 cm. The polylactic acid fiber is a bicomponent sheath-core structure polylactic acid fiber with a fiber fineness of 2.5-5d, a fiber length of 4-5 cm, a sheath layer of PBAT with a melting point of around 130℃, and a core layer of PLA with a melting point of 165-170℃.

[0012] The polylactic acid fiber has a two-component core-sheath structure.

[0013] The weight of the jute fiber nonwoven fabric is 40-120 g / m².

[0014] The method for producing the above-mentioned jute fiber nonwoven fabric according to the present invention includes the following steps:

[0015] a. Preparation of jute fiber: Use the short jute fibers that have been combed in each process of the jute textile production line to remove ash and impurities; or cut the jute fibers that have been normally combed by jute carding machines C111 and C121 into lengths of 3-3.5 cm, and then comb them twice by cotton type carding machine to increase the fiber count, so that the average count of the combed process fiber reaches more than 900 count.

[0016] b. Unpacking and weighing: The components and weight parts of the mixed raw materials are as follows: jute fiber 40-60, polylactic acid fiber 30-33, cotton fiber 36-40; the cotton fiber fineness is 2.5-5d, and the fiber length is 4-5 cm.

[0017] c. Opening, mixing, condensing and vibrating feeding: The raw materials are sequentially processed through opening, mixing, re-opening, re-mixing, condensing and vibrating feeding;

[0018] d. Carding: The fiber web output by the vibrating cotton feeder is carded. The carding process uses a single cylinder, double doffer, and double randomized roller carding machine. The cylinder speed is 700 m / min, the working roller speed is 40 m / min, the doffer speed is 20 m / min, the front randomized roller speed is 13 m / min, the rear randomized roller speed is 10 m / min, the feed speed is 0.4 m / min, and the output speed is 16 m / min. The weight of each layer of the upper and lower fiber web is 5-10 g / m². Both the cylinder and the working roller use self-locking needle cloth.

[0019] e. Web laying: The two layers of fiber web output from the upper and lower doffers of the upper carding machine are guided through the conveyor curtain to the web laying machine and laid on the bottom curtain in the vertical flow direction by the reciprocating and uniform oscillation. When laying the web, 4-6 layers of web are stacked, the web laying speed is 18.5 meters / minute, and the drop between the bottom curtain and the transition curtain of the clamping feeder is less than 5 centimeters.

[0020] f. Needle Punching: The fiber web output from the laying screen onto the bottom curtain is guided through the first needle punching stage via a second curtain. It then passes through four needle punching stages in sequence. The first and third stages are downward needle punching, while the second and fourth stages are upward needle punching. The needle densities are 17.61 n / cm², 36.14 n / cm², 56.01 n / cm², and 60.02 n / cm², respectively. A fiber web guiding conveyor curtain is installed between the output and feed of the first and second needle punching stages and the second and third needle punching stages to prevent uneven corrugations caused by gravity stretching and vibration of the fiber web. The output speeds of the four needle punching stages are 4.0 m / min, 4.3 m / min, 4.7 m / min, and 5.2 m / min, respectively, and the step sizes of the four needle punching stages are 14.3 mm / t, 14.8 mm / t, 15.5 mm / t, and 16.5 mm / t, respectively.

[0021] g. Temperature and pressure controlled rolling: The fiber mesh after the last needle punching is rolled by semi-covered oil-heated upper and lower rollers to form a membrane material with a mesh structure, thus obtaining jute fiber nonwoven fabric. The rolling pressure is 3-4 MPa and the speed is 3-5 meters / minute.

[0022] There is also a rolling step, in which the film is fed from the heat-pressing rollers into the winding machine for winding. The winding process includes optical control edge trimming, longitudinal edge cutting at both ends, CNC length counting, synchronous winding, and slit cutting.

[0023] The opening, blending, condensing, and vibratory feeding steps are performed using a Yingyang 1500ASFZ-KB opening machine, a Yingyang 1360ASFZ-KA blending machine, and a Yingyang 1700ASFZ-J condensing and feeding machine.

[0024] The combing step was performed using a Yingyang 1500ASFZ-GS combing machine.

[0025] The net laying step was performed using the Yingyang 3200ASFZ-GP net laying machine.

[0026] The acupuncture procedure was performed using a Yingyang 3200ASFZ-GZ series acupuncture machine with the following needle models: First and second needles: 15×16×32×3.5H—30—GB332 / R—Y53201; Third and fourth needles: 15×18×40×3m24—30—G222 / C—Y53201.

[0027] The temperature and pressure controlled ironing step is performed using a Yingyang 3200ASFZ ironing machine.

[0028] This invention overcomes the shortcomings of the prior art and achieves the purpose of the invention. The biodegradable jute fiber nonwoven fabric of this invention has good seam strength, reliable adhesion of the handles, and has the unique texture of jute fiber. The shopping bags made from it can bear a weight of more than 8 kg and are priced at about 0.7 yuan each. It fully meets the needs of making shopping bags that can be promoted and used in the market, and also has the advantages of environmental protection and cost.

[0029] The parameter tests for the product of this invention are shown in the table below (samples were sent to Shanghai Textile Group Testing and Standards Co., Ltd. for testing):

[0030]

[0031] The product of this invention has been tested by SGS (composting degradation method ISO14855-1:2012) and its biodegradation rate after 90 days is 55.6%, which fully meets the environmental protection requirements.

[0032] The jute fiber nonwoven fabric of this invention is made of jute fiber, bicomponent polylactic acid fiber with a core-sheath structure, and cotton fiber, with weight parts of 40-60, 30-33, and 36-40, respectively. Through extensive experimentation, the applicant discovered that only the composition and dosage of these raw materials can achieve the purpose of the invention and satisfy the balance requirements between strength and cost.

[0033] The jute fibers of this invention have an average count of 900 or more and an average fiber length of 3-3.5 cm. Through extensive testing, the applicant discovered that using these high-count short fibers ensures good fiber adhesion during subsequent heat treatment and film formation, resulting in a smooth, fuzz-free film surface and ensuring that the finished shopping bags can bear a weight of over 8 kg.

[0034] The polylactic acid (PLA) fiber raw material used in this invention is a bicomponent core-sheath structure PLA fiber from Quanzhou Smartin Import & Export Trading Co., Ltd. Its fiber fineness is 2.5-5d, fiber length is 4-5 cm, the sheath layer is PBAT (polybutylene terephthalate-adipate), melting point is around 130℃, and the core layer is PLA (polylactic acid), melting point is 165-170℃. Other PLA fibers tested could not achieve the purpose of this invention. Other PLA fibers have the following problems: poor fluidity in the melt state, slow solidification upon cooling, poor film formation, low strength, and when processed into bags using an integrated bag-making machine, the seam strength is low, and some cannot be sewn or attached to carrying straps at all.

[0035] Comparison table of technical indicators for nonwoven fabrics processed from different polylactic acid fibers

[0036]

[0037] The following table shows a comparison of the results of seam and handle attachment tests on the product of this invention with nonwoven fabrics processed using other types of polylactic acid fibers and polypropylene resin fibers on an integrated bag-making machine:

[0038]

[0039]

[0040] However, the applicant found in the experiment that the production of polylactic acid fiber with a bicomponent core-sheath structure from Quanzhou Smartin Import & Export Trading Co., Ltd. has strict requirements for the ironing process, which must meet the following conditions: temperature 155-158℃, double hot rollers, speed 3-5 meters / minute, and pressure 3-4 MPa.

[0041] To achieve the objectives of this invention, a biodegradable jute fiber nonwoven fabric suitable for making shopping bags is produced. This invention employs a novel method: comprehensively utilizing jute fiber pretreatment, opening, blending, coagulation, vibration feeding, carding, web formation, needle punching, and temperature and pressure controlled ironing, along with specific conditions. The jute fiber pretreatment ensures an average fiber count of over 900 count and an average fiber length of 3-3.5 cm, resulting in high-count short fibers. The opening, blending, coagulation, and vibration feeding processes sequentially open, mix, re-open, re-mix, coagulate, and vibrate feed to overcome uneven mixing caused by significant differences in the fineness and hardness of jute fibers compared to blended fibers; therefore, a two-stage opening and mixing process is specifically included. In the carding step, the fiber web output from the previous vibration feeder undergoes this carding process, improving fiber orientation distribution. The longitudinal strength of the fiber web is significantly improved, and the basis weight control per unit area is more precise, resulting in uniform fiber combing and low damage to hemp fibers, and balanced fiber web quality per unit area. The web-laying process employs ultra-thin multi-layer web technology, with 4-6 layers stacked, each layer weighing 10-20 g / m², greatly improving the transverse tensile strength of the fiber web. The needle-punching process involves four needle-punching stages, with progressively increasing needle density, web exit speed, and step size, causing the multi-layered web fibers to entangle vertically, further enhancing the tensile strength of the fiber web. Temperature and pressure controlled rolling, through a reasonable combination of hot rolling temperature, pressure, and time, achieves moderate melting of the PBAT outer layer of PLA fibers. This utilizes the molten portion for bonding and reinforcement while retaining the fiber entanglement function, increasing the flexibility and strength of the nonwoven membrane material, thus achieving the goal of strengthening the nonwoven membrane material while maintaining its softness. Detailed Implementation

[0042] The present invention will now be described in detail:

[0043] This invention relates to a biodegradable jute fiber nonwoven fabric for manufacturing high-end shopping bags. It is made from jute fiber, bicomponent core-sheath structure polylactic acid fiber, and cotton fiber, with weight proportions of 40-60, 30-33, and 36-40, respectively. The jute fiber is uniformly mixed with the bicomponent core-sheath structure polylactic acid fiber and cotton fiber, and then carded into a single-layer fiber web with a basis weight of 10-20 g / m². This web is then stacked in 4-6 layers to form a multi-layer composite web. Four needle-punching processes are then performed to entangle the fibers in the multi-layer composite web. Finally, the web is passed through double-hot rollers at 155-158℃ at a speed of 3-5 m / min. The film is formed by online rolling of bicomponent polylactic acid (PLA) fiber in a molten state, and then immediately cooled and solidified after exiting the roller to form a mesh-like membrane material. The jute fiber has an average count of over 900 metric counts and an average fiber length of 3-3.5 cm. The PLA fiber is a bicomponent core-sheath structure PLA fiber from Quanzhou Smart Import & Export Trading Co., Ltd., with a fiber fineness of 2.5-5d and a fiber length of 4-5 cm. The sheath layer is PBAT (polybutylene terephthalate), with a melting point of around 130°C, and the core layer is PLA (polylactic acid), with a melting point of 165-170°C.

[0044] The weight of this jute fiber nonwoven fabric is 40-120 grams per square meter. Shopping bags made from it can support a weight of over 8 kilograms.

[0045] The steps for producing jute fiber nonwoven fabric are as follows:

[0046] a. Jute fiber pretreatment: The jute fiber used in this invention is selected from virgin high-count short fibers that have not undergone biological enzyme or chemical treatment. Jute fiber has high lignin and pectin content and strong rigidity. The process bundles of jute textile combing are coarse and hard, and the ends of the fibers are not conducive to subsequent ironing and bonding, which easily forms film surface hairs. Therefore, the jute short fibers (after removing ash impurities) from each process after combing in the jute textile production line can be used. At the same time, in order to ensure a stable and continuous supply of raw materials, the fibers that are normally combed by jute combing machines (C111 and C121) can also be cut into 3-4 cm lengths and then combed a second time by cotton-type combing machines to increase the fiber count. The average count of the process fibers after combing is controlled above 900 count.

[0047] b. Unpacking and Weighing (Jiangsu Yingyang Nonwoven Machinery Co., Ltd., hereinafter referred to as Yingyang 1200 Electronic Weighing and Unpacking Machine): After unpacking, each raw material component is weighed by CNC electronic weighing and put into production according to the weight ratio. The weight ratio of jute fiber meeting the above conditions a) is 40-60%; the weight ratio of polylactic acid fiber with a two-component core-sheath structure (sheath: PBAT, polybutylene terephthalate-adipate, melting point about 130℃; core: polylactic acid (PLA), melting point 165-170℃) is 30-40%, with a fiber fineness of 2.5-5d and a fiber length of 4-5 cm; cotton fiber (or viscose fiber, fiber fineness 2.5-5d, fiber length 4-5 cm) is 30-40%. The fine and soft cotton-type fibers are needle-punched and entangled with the jute fibers, and the synergistic effect between fibers is brought into play to solve the product strength problem. The cotton-type fibers have a high count and good dispersion, which can improve the flatness of the fiber web.

[0048] c. Opening (Yingyang 1500ASFZ-KB), Blending (Yingyang 1360ASFZ-KA), Cotton Condensation and Vibratory Feeding (Yingyang 1700ASFZ-J): After the initial packaging process, various raw materials are added in proportion and sequentially undergo opening, mixing, re-opening, re-mixing, condensation, and vibratory feeding. Due to the significant differences in fineness and hardness between jute fibers and the blended fibers, uneven mixing is easily caused. Therefore, a second opening and mixing step is configured to improve this. In principle, the various fibers in the blend should have good dispersibility and be evenly mixed. Conventional light-controlled linkage can be used for feeding in this process.

[0049] d. Carding (Yingyang 1500ASFZ-GS): The fiber web output from the previous vibrating feeder undergoes this carding process, improving fiber orientation distribution, significantly enhancing longitudinal strength, and allowing for more precise control of fiber web weight per unit area. The carding process employs a single cylinder, double doffer, and double randomized roller carding machine. To ensure uniform fiber carding and minimal damage to hemp fibers, the cylinder and working roller speeds are optimized, using a cylinder speed of 700 m / min and a working roller speed of 40 m / min. To ensure uniform fiber web quality per unit area, and to ensure the doffer (speed selected at 20 m / min) completely strips fibers from the cylinder in one pass, the spacing must be minimized (the upper doffer and cylinder spacing is a No. 7 spacing plate, and the lower doffer and cylinder spacing is a No. 14 spacing plate). To ensure the transverse tensile strength of the fiber web, a double randomized roller is used (the front randomized roller speed is designed to be 13 m / min, and the rear randomized roller speed is approximately 10 m / min). The feed (0.4 m / min) and output (16 m / min) speed ratio is controlled by a small draw ratio, and the basis weight of each layer of the upper and lower fiber web is controlled at 5-10 g / m². Both the cylinder and the working roller use self-locking needle cloth.

[0050] e-laying (Yingyang 3200ASFZ-GP): Two layers of fiber web output from the upper and lower carding machines are guided through a conveyor curtain to the web laying machine, which reciprocates at a uniform speed and lays them on the bottom curtain in the vertical flow direction. This process greatly improves the lateral tensile strength of the fiber web. The number of fiber web layers is controlled by controlling the output speed of the bottom curtain. To ensure the uniformity of the membrane material per unit area, an ultra-thin multi-layer web laying technology is adopted. 4-6 layers are laid during web laying, with each layer weighing 10-20 g / m². To reduce the impact of airflow drift and irregular stretching caused by the weight of the fiber web on the quality of the web, the distance between the guide roller of the web laying machine and the bottom curtain is kept as small as possible. The web laying speed is about 18.5 m / min, generally maintained at 30-40 cm. The drop difference between the bottom curtain and the transition curtain of the clamping feeder is less than 5 cm to avoid unevenness caused by the gravity stretching of the fiber web.

[0051] f. Needle Punching Process (Yingyang 3200ASFZ-GZ-A, B, C, D): The fiber web laid out onto the bottom curtain is guided through the intermediate curtain to the first needle punching stage, and then passes through four needle punching stages in sequence. The first and third stages are downward needle punching, and the second and fourth stages are upward needle punching. The needle densities are 17.61 n / cm², 36.14 n / cm², 56.01 n / cm², and 60.02 n / cm², respectively. Needle models: First and second needle punches: 15×16×32×3.5H—30—GB332 / R—Y53201; Third and fourth needle punches: 15×18×40×3m²4—30—G222 / C—Y53201. A fiber mesh guide conveyor curtain is installed between the output and feed of the first and second and second and third needle punching stages to prevent uneven corrugations caused by gravity stretching and vibration of the fiber mesh. The output speed of the four needle punching stages increases slightly in sequence, selected as 4.0-4.3-4.7-5.2 m / min respectively. The stepping amount of the four needle punching stages also increases in sequence, selected as 14.3-14.8-15.5-16.5 mm / t respectively.

[0052] g. Temperature and Pressure Controlled Rolling (Yingyang 3200ASFZ): After the final needle-punching, the fiber mesh is rolled by semi-covered oil-heated (evenly heated) upper and lower rollers (the surface is treated with Teflon or other non-stick coatings). The PBAT sheath layer of the bicomponent polylactic acid fiber with a core-sheath structure melts at 155-158℃, bonding the mixed fiber mesh. After exiting the rollers, it immediately cools and solidifies into a mesh film. The pressure is controlled at 3-4MPa, and the speed is controlled at 3-5 meters / minute. If the temperature is too low or the speed is too high, the PBAT melting state is poor, resulting in poor fluidity and uneven film formation. If the temperature is too high or the speed is too low, the film is brittle and has poor flexibility. The hot rolling process, through a reasonable combination of hot rolling temperature, pressure, and time, achieves moderate melting of the PBAT sheath layer of PLA fibers. It utilizes the molten part to play a bonding and reinforcing role, while allowing the fibers to retain their entanglement function. The increased flexibility enhances the strength of the nonwoven film material, achieving the goal of strengthening the nonwoven film material while maintaining its softness.

[0053] h. Rolling: After the film is output from the heat exchanger, it is fed into the winding machine. The winding process includes optical control edge trimming, longitudinal edge cutting at both ends, CNC length counting, synchronous winding, and sizing.

Claims

1. A biodegradable jute fiber nonwoven fabric for making high-end shopping bags, characterized in that: The jute fiber nonwoven fabric is made of jute fiber, bicomponent core-sheath polylactic acid fiber and cotton fiber, with weight parts of 40-60, 30-33 and 36-40 respectively. The jute fiber is mixed evenly with the bicomponent core-sheath polylactic acid fiber and cotton fiber and then carded into a single-layer fiber web with a basis weight of 10-20 g / m². Then, it is stacked into a multi-layer composite web by 4-6 layers. Then, it is subjected to 4 needle punching processes to make the fibers of the multi-layer composite web entangled. Finally, it is rolled online at a speed of 3-5 m / min by double hot rollers at 155-158℃. The bicomponent polylactic acid fiber sheath is melted and rolled into a film. After exiting the roller, it is immediately cooled and solidified to form a mesh structure film material. The jute fiber has an average count of over 900 counts and an average length of 3-3.5 cm. The polylactic acid fiber is a bicomponent core-sheath structure polylactic acid fiber with a fiber fineness of 2.5-5d and a fiber length of 4-5 cm. The sheath layer is PBAT with a melting point of around 130°C, and the core layer is PLA with a melting point of 165-170°C.

2. The jute fiber nonwoven fabric according to claim 1, characterized in that: The weight of the jute fiber nonwoven fabric is 40-120 g / m².

3. A method for producing jute fiber nonwoven fabric as described in claim 1 or 2, characterized in that... Includes the following steps: a. Preparation of jute fiber: Use the short jute fibers that have been combed in each process of the jute textile production line to remove ash and impurities; or cut the jute fibers that have been normally combed by jute carding machines C111 and C121 into lengths of 3-3.5 cm, and then comb them twice by cotton type carding machine to increase the fiber count, so that the average count of the combed process fiber reaches more than 900 count. b. Unpacking and weighing: The components and weight parts of the mixed raw materials are as follows: jute fiber 40-60, polylactic acid fiber 30-33, cotton fiber 36-40; the cotton fiber fineness is 2.5-5d, and the fiber length is 4-5 cm. c. Opening, mixing, condensing and vibrating feeding: The raw materials are sequentially processed through opening, mixing, re-opening, re-mixing, condensing and vibrating feeding; d. Carding: The fiber web output by the vibrating cotton feeder is carded. The carding process uses a single cylinder, double doffer, and double randomized roller carding machine. The cylinder speed is 700 m / min, the working roller speed is 40 m / min, the doffer speed is 20 m / min, the front randomized roller speed is 13 m / min, the rear randomized roller speed is 10 m / min, the feed speed is 0.4 m / min, and the output speed is 16 m / min. The weight of each layer of the upper and lower fiber web is 5-10 g / m². Both the cylinder and the working roller use self-locking needle cloth. e. Web laying: The two layers of fiber web output from the upper and lower doffers of the upper carding machine are guided through the conveyor curtain to the web laying machine and laid on the bottom curtain in the vertical flow direction by the reciprocating and uniform oscillation. When laying the web, 4-6 layers of web are stacked, the web laying speed is 18.5 meters / minute, and the drop between the bottom curtain and the transition curtain of the clamping feeder is less than 5 centimeters. f. Needle Punching: The fiber web output from the laid-out screen onto the bottom curtain is guided through the first needle punching stage via a multi-stage curtain. It then passes through four needle punching stages in sequence. The first and third stages are downward needle punching, while the second and fourth stages are upward needle punching. The needle densities are 17.61 n / cm², 36.14 n / cm², 56.01 n / cm², and 60.02 n / cm², respectively. A fiber web guiding conveyor curtain is installed between the output and feed of the first and second needle punching stages and the second and third needle punching stages to prevent uneven corrugation caused by gravity stretching and vibration of the fiber web. The output speeds of the four needle punching stages are 4.0 m / min, 4.3 m / min, 4.7 m / min, and 5.2 m / min, respectively, and the step sizes of the four needle punching stages are 14.3 mm / t, 14.8 mm / t, 15.5 mm / t, and 16.5 mm / t, respectively. g. Temperature and pressure controlled rolling: The fiber mesh after the last needle punching is rolled by semi-covered oil-heated upper and lower rollers to form a membrane material with a mesh structure, thus obtaining jute fiber nonwoven fabric. The rolling pressure is 3-4 MPa and the speed is 3-5 meters / minute.

4. The method according to claim 3, characterized in that: There is also a rolling step, in which the film is fed from the heat-pressing rollers into the winding machine for winding. The winding process includes optical control edge trimming, longitudinal edge cutting at both ends, CNC length counting, synchronous winding, and slit cutting.

5. The method according to claim 3, characterized in that: The opening, blending, condensing, and vibratory feeding steps are performed using a Yingyang 1500ASFZ-KB opening machine, a Yingyang 1360ASFZ-KA blending machine, and a Yingyang 1700ASFZ-J condensing and feeding machine.

6. The method according to claim 3, characterized in that: The combing step was performed using a Yingyang 1500ASFZ-GS combing machine.

7. The method according to claim 3, characterized in that: The net laying step was performed using the Yingyang 3200ASFZ-GP net laying machine.

8. The method according to claim 3, characterized in that: The acupuncture procedure was performed using a Yingyang 3200ASFZ-GZ series acupuncture machine with the following needle models: First and second needles: 15×16×32×3.5H—30—GB332 / R—Y53201; Third and fourth needles: 15×18×40×3m24—30—G222 / C—Y53201.

9. The method according to claim 3, characterized in that: The temperature and pressure controlled ironing step is performed using a Yingyang 3200ASFZ ironing machine.

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