Manufacturing method of super-strong moisture-permeable and air-permeable synthetic leather

Abstract

The invention relates to the technical field of synthetic leather production, in particular to a manufacturing method of super-strong moisture-permeable and air-permeable synthetic leather, which comprises the following steps: preparing raw materials, impregnating PU, rolling and washing with hot water, forming a base, extracting vinylon after rolling and washing with hot water, leaving a tubular channel in the base, and finally forming the base with super-strong moisture-permeable and air-permeable performance. The synthetic leather manufactured through the method is of a tubular channel structure, compared with an existing micropore structure, the tubular channel has the better moisture-permeable and air-permeable efficiency and is smoother, gas and water vapor can pass through the tubular channel more quickly, and the moisture-permeable and air-permeable performance of the synthetic leather is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of synthetic leather production, and specifically to a manufacturing method of super-strong moisture-permeable and breathable synthetic leather. Background Art

[0002] Due to its advantages such as low cost, strong durability, and flexible design, synthetic leather is widely used in multiple fields, such as clothing, footwear, and furniture industries. Currently, the realization of the moisture-permeable and breathable performance of synthetic leather is mainly achieved through post-treatment of synthetic leather base. However, this existing method has certain limitations. Most of the existing moisture-permeable and breathable structures of synthetic leather are microporous structures. Although the microporous structures can achieve moisture permeability and air permeability to a certain extent, there are deficiencies in the efficiency and stability of moisture and air permeability. For example, the micropores are easily blocked, resulting in a decline in moisture and air permeability performance. Moreover, under different environmental conditions, its moisture and air permeability performance fluctuates greatly, making it difficult to meet the requirements of synthetic leather products with high moisture and air permeability requirements. Summary of the Invention

[0003] (I) Technical Problems to be Solved In view of the deficiencies of the prior art, the present invention provides a manufacturing method of super-strong moisture-permeable and breathable synthetic leather.

[0004] (II) Technical Solutions To achieve the above object, the present invention provides the following technical solutions: A manufacturing method of super-strong moisture-permeable and breathable synthetic leather, including the following steps: The first step: Preparation of raw materials; The second step: PU impregnation. Impregnate the prepared fiber and polyester needle-punched fabric with PU to make the material initially possess the basic characteristics of synthetic leather; The third step: Hot water rolling and washing. Perform hot water rolling and washing on the material after PU impregnation. During this process, due to the addition of a certain proportion of water-soluble vinylon during the formation of the base earlier, the vinylon will be extracted by water during hot water rolling and washing; The fourth step: Formation of the base. After hot water rolling and washing, the vinylon is extracted, leaving tubular channels in the base, and finally forming a base with super-strong moisture-permeable and breathable performance, that is, the manufacturing of super-strong moisture-permeable and breathable synthetic leather is completed.

[0005] Further, the improvement of the present invention is that the raw materials in the first step include fiber and polyester needle-punched fabric.

[0006] Further, the improvement of the present invention is that in the second step, the PU impregnation includes the following steps: The first step: Preparation of slurry; The second step: Pretreatment of fabric; The third step: Impregnation operation; The fourth step: Extrusion and scraping coating; The fifth step: Preliminary curing.

[0007] Furthermore, the improvements of the present invention are as follows. The slurry preparation includes steps such as raw material selection, ratio determination, and stirring and mixing. The fabric pretreatment includes steps such as impurity removal and cleaning, and preheating treatment. The impregnation operation includes steps such as putting into the dipping tank, controlling the time, and assisting penetration. The extrusion and scraping coating includes steps such as extruding the excess slurry and scraping and leveling. The preliminary curing includes steps such as entering the oven and curing reaction.

[0008] Furthermore, the improvements of the present invention are as follows. In the third step, the hot water rolling and washing includes the following steps: The first step: hot water preparation; The second step: preparation of the rolling and washing equipment; The third step: putting the synthetic leather into the rolling and washing equipment; The fourth step: hot water rolling and washing operation; The fifth step: post-treatment after rolling and washing.

[0009] Furthermore, the improvements of the present invention are as follows. The hot water preparation includes steps such as water quality selection, temperature adjustment, and addition of additives. The preparation of the rolling and washing equipment includes steps such as equipment inspection and roll cleaning. Putting the synthetic leather into the rolling and washing equipment includes steps such as stable feeding and guiding and fixing. The hot water rolling and washing operation includes steps such as primary rolling and washing, multiple cycle rolling and washing, and observing the cleaning effect. The post-treatment after rolling and washing includes steps such as squeezing out the water, rinsing with clear water, and cloth discharging and collecting.

[0010] Furthermore, the improvements of the present invention are as follows. The time of primary rolling and washing is generally 1 min - 3 min. The time and pressure of each cycle of rolling and washing can be appropriately adjusted according to the actual situation. Generally, the time of each rolling and washing is slightly shorter than that of the primary rolling and washing, between 0.5 min - 2 min.

[0011] Furthermore, the improvements of the present invention are as follows. The rinsing time is generally 1 min - 2 min.

[0012] (III) Beneficial effects Compared with the prior art, the present invention provides a method for manufacturing a super moisture-permeable and breathable synthetic leather, having the following beneficial effects: The synthetic leather manufactured by the content of the present application forms a tubular channel structure. Compared with the existing microporous structure, the tubular channel has better moisture-permeable and breathable efficiency. The tubular channel is smoother, and gas and water vapor can pass through more quickly, greatly improving the moisture-permeable and breathable performance of the synthetic leather; The tubular channel structure is not easily blocked. Under different environmental conditions, such as when the humidity and temperature change greatly, it can still maintain stable moisture-permeable and breathable performance, and will not, like the microporous structure, cause a large fluctuation in performance due to environmental changes; Due to its excellent moisture permeability and air permeability, it can better meet the requirements of synthetic leather products with high moisture permeability and air permeability, thus broadening the application fields of synthetic leather. For example, it can also be applied in fields with strict requirements for material moisture permeability and air permeability, such as high-end outdoor sports equipment and medical supplies. Detailed implementation manners

[0013] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0014] A manufacturing method of a super moisture-permeable and air-permeable synthetic leather of the present invention includes the following steps: The first step: Raw material preparation; The second step: PU impregnation. Impregnate the prepared fiber and polyester needle-punched fabric with PU to make the material initially possess the basic characteristics of synthetic leather; The third step: Hot water rolling and washing. Perform hot water rolling and washing on the material after PU impregnation. During this process, due to the addition of a certain proportion of water-soluble vinylon in the formation of the base fabric in the early stage, the vinylon will be extracted by water solubility during hot water rolling and washing; The fourth step: Forming the base fabric. After hot water rolling and washing, the vinylon is extracted, leaving tubular channels in the base fabric, and finally forming a base fabric with super moisture permeability and air permeability, that is, the manufacturing of the super moisture-permeable and air-permeable synthetic leather is completed.

[0015] Furthermore, the improvement of the present invention is that the raw materials in the first step include fiber and polyester needle-punched fabric.

[0016] Furthermore, the improvement of the present invention is that in the second step, the PU impregnation includes the following steps: The first step: Slurry preparation; The second step: Fabric pretreatment; The third step: Impregnation operation; The fourth step: Extrusion and scraping; The fifth step: Preliminary curing.

[0017] Furthermore, the improvement of the present invention is that the slurry preparation includes steps such as raw material selection, ratio determination, and stirring and mixing. The fabric pretreatment includes steps such as impurity removal and cleaning and preheating treatment. The impregnation operation includes steps such as putting into an immersion tank, controlling time, and assisting penetration. The extrusion and scraping includes steps such as extruding excess slurry and scraping to be flat. The preliminary curing includes steps such as entering an oven and curing reaction.

[0018] Furthermore, the improvement of the present invention is that in the third step, the hot water rolling and washing includes the following steps: Step 1: Preparation of hot water; Step 2: Preparation of calendaring and washing equipment; Step 3: Putting the synthetic leather into the calendaring and washing equipment; Step 4: Calendaring and washing operation with hot water; Step 5: Post-treatment after calendaring and washing.

[0019] Furthermore, the improvements of the present invention are as follows. The preparation of hot water includes steps such as water quality selection, temperature adjustment, and addition of additives. The preparation of calendaring and washing equipment includes steps such as equipment inspection and calendar roll cleaning. Putting the synthetic leather into the calendaring and washing equipment includes steps such as smooth feeding and guiding and fixing. The calendaring and washing operation with hot water includes steps such as primary calendaring and washing, multiple cycle calendaring and washing, and observing the cleaning effect. The post-treatment after calendaring and washing includes steps such as squeezing out water, rinsing with clean water, and fabric discharging and collecting.

[0020] Furthermore, the improvements of the present invention are as follows. The time for primary calendaring and washing is generally 1 min - 3 min. The time and pressure for each cycle of calendaring and washing can be appropriately adjusted according to the actual situation. Generally, the time for each calendaring and washing is slightly shorter than that of primary calendaring and washing, between 0.5 min - 2 min.

[0021] Furthermore, the improvements of the present invention are as follows. The rinsing time is generally 1 min - 2 min.

[0022] The specific steps of PU impregnation are as follows: Selection of raw materials for slurry preparation: According to the performance requirements of the synthetic leather, select appropriate PU resins, such as polyester-based PU resins or polyether-based PU resins. The former has better wear resistance and hydrolysis resistance, while the latter has better flexibility and low-temperature performance. At the same time, select supporting solvents, such as DMF (dimethylformamide), MEK (methyl ethyl ketone), etc., and additives, such as plasticizers, stabilizers, color pastes, etc.

[0023] Determination of proportion: According to the specific requirements of the product, accurately determine the proportion of each raw material. For example, if the synthetic leather needs to have higher softness, the proportion of plasticizer can be appropriately increased; if aging resistance is emphasized, the amount of stabilizer can be adjusted accordingly.

[0024] Stirring and mixing: Put the weighed PU resin, solvent, additive, etc. into the stirring equipment and stir at an appropriate speed and time. Generally, the stirring speed is 500 - 1000 revolutions per minute, and the stirring time is 1 - 2 hours to make each component fully mixed and form a uniform and stable PU slurry.

[0025] Pretreatment of fabric for impurity removal and cleaning: Check the fiber and polyester needle-punched fabric and remove possible impurities and foreign matters therein, such as dust, lint, etc., which can be carried out by means such as dust suction and screening.

[0026] Preheating treatment: Put the cleaned fibers and polyester needle punched fabrics into a preheating device and heat them to a certain temperature, usually between 40 - 60°C. Preheating can make the fiber structure of the fabric loose and improve the permeability of the PU slurry.

[0027] Impregnation operation - putting into the dipping tank: Slowly put the pretreated fibers and polyester needle punched fabrics into the dipping tank filled with PU slurry, ensuring that the fabric is completely immersed in the slurry to avoid the appearance of bubbles or floating phenomena.

[0028] Controlling time: Determine the appropriate impregnation time according to the thickness, density of the fabric and the performance of the PU slurry, generally 10 - 30 minutes, so that the PU slurry can fully penetrate into the interior and gaps of the fibers and needle punched fabrics.

[0029] Auxiliary penetration: To promote the uniform penetration of the PU slurry, an ultrasonic device can be set in the dipping tank or mechanical stirring can be used to enhance the fluidity and permeability of the slurry. However, attention should be paid to controlling the intensity to avoid damaging the fabric.

[0030] Squeezing and scraping to extrude excess slurry: After impregnation, take the fabric out of the dipping tank and extrude it through a squeezing roller to extrude the excess PU slurry in the fabric, so that the amount of slurry attached to the fabric reaches an appropriate level. The squeezing pressure is generally controlled at 0.5 - 1.5 MPa.

[0031] Scraping and leveling: Use a scraper or scraping equipment to scrape the surface of the fabric, making the PU slurry more evenly distributed on the fabric surface and the thickness more consistent, while removing possible slurry accumulation or unevenness on the surface.

[0032] Initial curing - sending into the oven: Send the fabric after squeezing and scraping into an oven or drying equipment for initial curing. The oven temperature is set at 80 - 120°C and the drying time is 10 - 20 minutes.

[0033] Curing reaction: Under heating conditions, the solvent in the PU slurry gradually volatilizes, and the PU resin undergoes a cross - linking reaction, initially curing on the fabric to form a PU coating with certain strength and stability.

[0034] Hot water rolling and washing usually includes the following steps: Preparing hot water; Water quality selection: Select water that meets the production requirements, generally deionized water or softened water, to reduce the impact of impurities in the water on the synthetic leather and avoid the formation of scale or other chemical reactions during the rolling and washing process, which may affect the quality and performance of the synthetic leather.

[0035] Temperature adjustment: Heat the water to an appropriate temperature. Usually, the hot water temperature is controlled around 80°C - 100°C. Within this temperature range, the water-soluble vinylon can be better dissolved and extracted, and at the same time, it will not cause excessive damage to other components and structures of the synthetic leather.

[0036] Additives (optional): According to actual production needs, sometimes a small amount of additives, such as surfactants, are added to the hot water. These additives can help improve the water washing effect, promote the dissolution and removal of water-soluble vinylon, and at the same time help to wash away some impurities that may remain during the PU impregnation process. However, attention should be paid to the types and dosages of additives to avoid adverse effects on the synthetic leather.

[0037] Preparation of calendering and washing equipment; Equipment inspection: Before hot water calendering and washing, conduct a comprehensive inspection of the calendering and washing equipment, including the flatness of the calender rolls, rotational flexibility, and whether the pressure adjustment device is normal, etc., to ensure that the equipment can operate normally and avoid failures during the calendering and washing process, which may affect the production progress and product quality.

[0038] Cleaning of calender rolls: Clean the surface of the calender rolls to remove impurities such as dust and oil stains that may adhere to them, preventing these impurities from contaminating the synthetic leather during the calendering and washing process. Special cleaning agents and cleaning tools can be used for cleaning, and then rinse with clean water and dry.

[0039] Parameter adjustment: According to the thickness, material of the synthetic leather and production process requirements, adjust the parameters of the calendering and washing equipment, such as the pressure of the calender rolls, calendering and washing speed, etc. Generally, the calender roll pressure is between 0.5 MPa - 1.5 MPa, and the calendering and washing speed is 5 m / min - 15 m / min. Specific parameters need to be fine-tuned according to the actual situation.

[0040] Put the synthetic leather into the calendering and washing equipment; Smooth feeding: Feed the synthetic leather that has been preliminarily cured by PU impregnation smoothly into the calendering and washing equipment, ensuring that the synthetic leather is in a correct position when entering the calendering and washing area, without skewing, wrinkling, etc., so as not to affect the uniformity of the calendering and washing effect.

[0041] Guiding and fixing: Use feeding guiding devices, such as guide rolls and conveyor belts, to accurately guide the synthetic leather between the calender rolls and fix it appropriately to prevent the synthetic leather from shifting or sliding during the calendering and washing process.

[0042] Hot water calendering and washing operation; Initial calendering and washing: After the synthetic leather enters the calender rolls, it comes into full contact with the hot water and starts the initial calendering and washing. Under the pressure of the calender rolls, the hot water penetrates into the synthetic leather and reacts with the water-soluble vinylon in it, causing it to gradually dissolve. The initial calendering and washing time is generally 1 min - 3 min to allow the hot water enough time to contact and start the dissolution process with the water-soluble vinylon.

[0043] Multiple - cycle rolling and washing: To more thoroughly dissolve and extract water - soluble vinylon, multiple - cycle rolling and washing are usually required. After passing through the rollers, the synthetic leather enters a hot - water tank and soaks for a period of time, and then passes through the rollers again for rolling and washing. This cycle is repeated 2 - 3 times. The time and pressure for each cycle of rolling and washing can be appropriately adjusted according to the actual situation. Generally, the time for each rolling and washing is slightly shorter than that of the first rolling and washing, between 0.5 min and 2 min.

[0044] Observe the cleaning effect: During the rolling - washing process, the operator needs to continuously observe the cleaning effect of the synthetic leather, check whether the water - soluble vinylon has been fully dissolved and extracted, and whether there are still residual vinylon or other impurities on the surface and inside of the synthetic leather. It can be judged by observing the turbidity of the water after rolling and washing, the appearance and feel of the synthetic leather, etc.

[0045] Post - treatment after rolling and washing; Squeeze out water: After the rolling and washing is completed, most of the water in the synthetic leather is squeezed out through rollers or extrusion devices, reducing the water content of the synthetic leather, which is convenient for subsequent drying and other processing steps. The water content of the squeezed - out synthetic leather is generally controlled at about 30% - 50%.

[0046] Rinse with clear water (optional): To further remove possible residual impurities and additives on the surface of the synthetic leather, sometimes the synthetic leather is rinsed with clear water. The rinsing time is generally 1 min - 2 min to make the surface of the synthetic leather cleaner.

[0047] Take out the cloth and collect: The synthetic leather after post - treatment of rolling and washing is smoothly sent out from the rolling - washing equipment, and a winding device is used to wind it up neatly, waiting to enter the next production process, such as drying, shaping, etc.

[0048] High - efficiency moisture permeability and air permeability: The synthetic leather manufactured by the content of this application forms a tubular channel structure. Compared with the existing microporous structure, the tubular channel has better moisture - permeability and air - permeability efficiency. The tubular channel is more unobstructed, and gas and water vapor can pass through more quickly, greatly improving the moisture - permeability and air - permeability performance of the synthetic leather.

[0049] Strong stability: The tubular channel structure is not easily blocked. Under different environmental conditions, such as when the humidity and temperature change greatly, it can still maintain stable moisture - permeability and air - permeability performance, and will not have a large - scale fluctuation in performance like the microporous structure due to environmental changes.

[0050] Wide application range: Because of its excellent moisture - permeability and air - permeability performance, it can better meet the requirements of synthetic leather products with high moisture - permeability and air - permeability requirements, thus broadening the application field of synthetic leather. For example, it is also applicable in fields with strict requirements for material moisture - permeability and air - permeability, such as high - end outdoor sports equipment and medical supplies.

[0051] In the description herein, it should be noted that relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Also, the terms "comprises", "comprising", or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0052] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A manufacturing method of super moisture-permeable and breathable synthetic leather, characterized in that: It includes the following steps: The first step: Raw material preparation; The second step: PU impregnation. Impregnate the prepared fibers and polyester needle punched fabric with PU to make the material initially possess the basic characteristics of synthetic leather; The third step: Hot water rolling and washing. Conduct hot water rolling and washing on the material after PU impregnation. During this process, due to the addition of a certain proportion of water-soluble vinylon in the formation of the base fabric in the early stage, the vinylon will be extracted by water solubility during hot water rolling and washing; The fourth step: Forming the base fabric. After hot water rolling and washing, the vinylon is extracted, leaving tubular channels in the base fabric, and finally forming a base fabric with super moisture permeability and air permeability, that is, completing the manufacture of super moisture permeable and air permeable synthetic leather.

2. The manufacturing method of a super moisture-permeable and breathable synthetic leather according to claim 1, characterized in that: The raw materials in the first step include fibers and polyester needle punched fabric.

3. A method for manufacturing a super moisture-permeable and breathable synthetic leather according to claim 2, characterized in that: In the second step, the PU impregnation includes the following steps: The first step: Slurry preparation; The second step: Fabric pretreatment; The third step: Impregnation operation; The fourth step: Extrusion and scraping; The fifth step: Preliminary curing.

4. A method for manufacturing a super moisture-permeable and breathable synthetic leather according to claim 3, characterized in that: The slurry preparation includes steps such as raw material selection, ratio determination, and stirring and mixing. The fabric pretreatment includes steps such as impurity removal and cleaning and preheating treatment. The impregnation operation includes steps such as putting into the impregnation tank, controlling the time, and assisting penetration. The extrusion and scraping includes steps such as extruding the excess slurry and scraping it flat. The preliminary curing includes steps such as entering the oven and curing reaction.

5. The manufacturing method of a super moisture-permeable and breathable synthetic leather according to claim 4, characterized in that: In the third step, the hot water rolling and washing includes the following steps: The first step: Hot water preparation; The second step: Preparation of the rolling and washing equipment; The third step: Putting the synthetic leather into the rolling and washing equipment; The fourth step: Hot water rolling and washing operation; The fifth step: Post-treatment after rolling and washing.

6. The method for manufacturing super moisture-permeable and breathable synthetic leather according to claim 5, characterized in that: The hot water preparation includes steps such as water quality selection, temperature adjustment, and addition of additives. The preparation of the rolling and washing equipment includes steps such as equipment inspection and roll cleaning. Putting the synthetic leather into the rolling and washing equipment includes steps such as smooth feeding and guiding and fixing. The hot water rolling and washing operation includes steps such as primary rolling and washing, multiple cycle rolling and washing, and observing the cleaning effect. The post-treatment after rolling and washing includes steps such as squeezing out the water, rinsing with clean water, and cloth discharging and collecting.

7. A method for manufacturing a super moisture-permeable and breathable synthetic leather according to claim 6, characterized in that: The time of primary rolling and washing is generally 1 min - 3 min. The time and pressure of each cycle of rolling and washing can be appropriately adjusted according to the actual situation. Generally, the time of each rolling and washing is slightly shorter than that of the primary rolling and washing, between 0.5 min - 2 min.

8. A method for manufacturing a super moisture-permeable and breathable synthetic leather according to claim 7, characterized in that: The rinsing time is generally 1 min - 2 min.