CN115029935A - A bio-based degradable impregnated scraping knitted fabric polyurethane synthetic leather veneer finished product - Google Patents

Abstract

The application relates to a bio-based degradable polyurethane synthetic leather veneer product containing dip-coating and scraping knitted fabric, and relates to the technical field of synthetic leather manufacturing. The base fabric of the synthetic leather veneer product is a cotton-polyester blended knitted fabric; The preparation steps are as follows: the first step: pre-impregnating the base cloth; the second step: coating the pre-impregnated base cloth, and the coating material includes a bio-based degradable polyurethane resin; the third step: making the bio-based degradable polyurethane resin; The degraded polyurethane resin solidifies on the surface of the base fabric; the fourth step: washing the base fabric with clean water, and washing the DMF on the base fabric; the fifth step: preheating, ironing, drying, and shaping the base fabric to obtain the bottom embryo; sixth Step: Scrape the solvent-based biodegradable polyurethane resin on the release paper, then put the release paper in an oven to heat to form a film, then attach the film to the bottom embryo, and finally dry to obtain a finished product. The synthetic leather veneer finished product obtained in the present application will not cause pollution to the surrounding environment and prevent harm to the health of personnel.

Description

A bio-based degradable impregnated scraping knitted fabric polyurethane synthetic leather veneer finished product

technical field

The present application relates to the technical field of synthetic leather manufacturing, in particular to a bio-based degradable impregnated squeegee knitted cloth polyurethane synthetic leather veneer product.

Background technique

At present, due to the wide range of uses of leather, such as the production of shoes and boots, the production of furniture, the production of luggage, etc., various kinds of leather are widely used, and the composition and structure of natural leather can be simulated as plastic products that can be used as substitute materials. Usually, the impregnated non-woven fabric is used as the mesh layer, and the microporous polyurethane layer is used as the grain layer. Its front and back are very similar to leather, and have a certain breathability, which is closer to natural leather than ordinary artificial leather.

In the related art, most synthetic leathers are made of non-woven fabrics with 100% chemical synthetic fibers (polyester, nylon) as the base, coated with synthetic resins and various plastics. It pollutes the environment, and most chemical fibers are uncomfortable to wear due to their incompatibility to the skin. And most of the synthetic leather manufacturing process uses dimethylformamide organics as the main solvent, which makes a large amount of dimethylformamide waste water and waste gas generated in the synthetic leather manufacturing. Or the synthetic leather is disposed of by burying the synthetic leather.

In view of the above-mentioned related technologies, the inventors believe that the biodegradation of synthetic leather is slow, and whether the synthetic leather is disposed of by burning or landfilling after use, it will pollute the surrounding environment and endanger human health.

SUMMARY OF THE INVENTION

In order to improve the slow biodegradation of synthetic leather, no matter whether the synthetic leather is disposed of by burning or landfilling after use, it will cause pollution to the surrounding environment and endanger the health of personnel. Cloth polyurethane synthetic leather veneer finished product.

The bio-based degradable impregnated knitted cloth polyurethane synthetic leather veneer product provided by the application adopts the following technical scheme:

A bio-based degradable impregnated scraping knitted fabric polyurethane synthetic leather veneer product, the base fabric of the synthetic leather veneer product is a cotton-polyester blended knitted fabric; the preparation steps of the synthetic leather veneer product are: the first step : Pre-impregnate the base fabric, the pre-impregnated materials include bio-based degradable polyurethane resin, DMF and ultra-fine graphene; the second step: coat on the pre-impregnated base fabric, and the coating material includes bio-based biodegradable degrade polyurethane resin; the third step: make the bio-based degradable polyurethane resin solidify on the surface of the base cloth; the fourth step: wash the base cloth with clean water, and wash the DMF on the base cloth; the fifth step: preheat the base cloth, Ironing, drying and shaping to obtain the bottom embryo; the sixth step: apply the solvent-based biodegradable polyurethane resin to the release paper, then put the release paper into the oven to heat to form a film, and then combine the film with the The bottom embryo is laminated, and finally dried to obtain the finished product; the pre-impregnation material is 80-100 parts of bio-based degradable polyurethane resin, 300-400 parts of DMF, and 5-10 parts of ultra-fine graphene; the coating slurry is bio-based degradable polyurethane 60-70 parts of resin, 30-40 parts of polyurethane resin, 100 parts of DMF, 5-10 parts of carboxymethyl cellulose, 5-10 parts of ultrafine graphene, 5-10 parts of ramie fiber powder and 2-5 parts of calcium gluconate .

Optionally, the preparation requirement of the pre-impregnation material is to first add ultrafine graphene and DMF into a vacuum stirred tank at 25-30°C and stir at 500-800r/min for 20-30min, and then add bio-based degradable polyurethane resin. After stirring at 1000-1500r/min for 30-40min, vacuum defoaming for 60-120min, and filtering with 100 mesh to obtain pre-impregnation working slurry.

Optionally, the preparation process of the coating slurry is to first add ultrafine graphene, ramie fiber powder, carboxymethyl cellulose, calcium gluconate and DMF into the vacuum stirring tank and stir at 500-800r/min for 30min. Add bio-based degradable polyurethane resin, stir at 1000-1500r/min for 60-120min, vacuum defoaming for 60-120min, and filter with 180-200 mesh to prepare coating working slurry for later use.

Optionally, in the first step, the temperature of pre-impregnation is 50-60°C, and the time of pre-impregnation is 3-5 hours; in the process of pre-impregnation, the pre-impregnated base fabric is continuously stirred.

Optionally, in the first step, the pre-impregnated base fabric is taken out from the pool, and then the base fabric is hung in a drying chamber at 20-30° C. for 5-7 minutes, and a recovery tank is installed in the drying chamber. The recovery tank is located on the lower side of the base cloth, and the recovery tank collects the pre-impregnated material; after the drying is completed, the base cloth is taken out from the drying chamber, and after the base cloth is taken out from the drying chamber, the base cloth is placed in the drying chamber. In the kneading machine, the base cloth is moved in the kneading machine for 3-5s, and then pre-impregnated for 15-20min.

Optionally, in the second step, the base fabric passes through the No. 1 scraper, the No. 2 scraper, and the No. 3 scraper in sequence, and the No. 1 scraper, the second scraper, and the third scraper respectively include a scraper. No. 1 scraper, No. 2 scraper and No. 3 scraper, the distance between the No. 1 scraper and the base cloth is 7-9cm, the distance between the No. 2 scraper and the base cloth is 1-3cm, and the No. 3 scraper is 1-3cm. The distance from the base fabric is 0.2-0.6 cm.

Optionally, in the second step, the No. 1 heater, the No. 2 heater and the No. 3 heater are included, and the No. 1 heater, the No. 2 heater, and the No. The scraper and No. 3 scraper correspond, and the temperature of the No. 1 heater is 20-30°C, the temperature of the No. 2 heater is 30-40°C, the temperature of the No. 3 heater is 40-50°C, and the temperature of the No. 1 heater is 40-50°C. There is a No. 1 blower on it, a No. 2 heater is provided with a No. 2 blower, and a No. 3 heater is provided with a No. 3 blower, and the No. 1 blower faces the No. 1 scraper, the No. 2 blower faces the No. 2 scraper, and the No. 3 blower faces Scraper number three.

Optionally, in the fourth step, the specific step of washing the base fabric is that the base fabric passes through the No. 1 pool, the No. 2 pool and the No. 3 pool in sequence at a speed of 0.5m/s, and the base fabric is immersed in the pool when passing through the pool. Medium; the No. 1 pool is salt water, and the No. 2 and No. 3 pools are clear water.

Optionally, in the fifth step, the time for ironing the base fabric is 1-3min, the temperature for drying the base fabric is 120-160°C, and the drying time for the base fabric is 4-8min, and the temperature for shaping the base fabric is 120-160°C. It is 120℃-160℃, and the time is 5-9s.

Optionally, in the sixth step, it includes a coating roller, a first leveling roller and a second leveling roller that are arranged opposite to each other, and the release paper passes between the two coating rollers at a speed of 0.3m/s, Pass through two first leveling rollers at a speed of 0.2m/s, and pass through two second leveling rollers at a speed of 0.1m/s; a bio-based degradable polyurethane resin is adsorbed on the coating roller, and the first leveling roller is The surfaces on the leveling roll and the second leveling roll are coated with a release coating.

To sum up, the present application includes the following beneficial technical effects of at least one bio-based degradable impregnated squeegee knitted cloth polyurethane synthetic leather veneer product:

In application, the base fabric of the synthetic leather veneer product is a cotton-polyester blended knitted fabric, and the preparation steps of the synthetic leather veneer product are as follows: Step 1: Pre-impregnate the base fabric, and the pre-impregnated material includes bio-based degradable polyurethane Resin, DMF and ultra-fine graphene; second step: coating on the pre-impregnated base cloth, and the coating materials include bio-based degradable polyurethane resin, polyurethane resin, DMF, carboxymethyl cellulose, ultra-fine graphite ene, ramie fiber powder and calcium gluconate; the third step: coagulate the bio-based degradable polyurethane resin on the surface of the base fabric; the fourth step: wash the base fabric with clean water, and wash the DMF on the base fabric; the fifth step: correct The base fabric is preheated, ironed, dried, and shaped to obtain the bottom embryo; the sixth step: apply the solvent-based biodegradable polyurethane resin to the release paper, and then put the release paper into the oven to heat to form a film, After that, the film is attached to the bottom embryo, and finally dried to obtain a finished product. The obtained synthetic leather veneer product will not pollute the surrounding environment and prevent harm to the health of personnel.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present application more clear, the following will clearly and completely describe the technical solutions of the embodiments of the present application in conjunction with the embodiments of the present application. Obviously, the described embodiments are some, but not all, embodiments of the present application. Based on the described embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. Words like "a" or "an" used in the description of the patent application and the claims of the present application do not indicate a quantitative limitation, but indicate that there is at least one.

The embodiment of the present application discloses a bio-based degradable impregnated squeegee knitted cloth polyurethane synthetic leather veneer product.

Example 1:

Synthetic leather is a plastic product that simulates the composition and structure of natural leather and can be used as a substitute material. During the preparation process of synthetic leather, the impregnated non-woven fabric is usually used as the mesh layer, and the microporous polyurethane layer is used as the mesh layer. Grain layer obtained. After the designer's improvement, the base fabric of the synthetic leather veneer product is a cotton-polyester blended knitted fabric.

The preparation steps of the synthetic leather veneer finished product are:

first step:

To pre-impregnate the base fabric, in order to improve the effect of pre-impregnation of the base fabric, the temperature of pre-impregnation is 50°C, and the time of pre-impregnation is 3h, so that the effect of pre-impregnation of the base fabric is greatly improved. During the pre-impregnation process of the base fabric, more base fabrics are often pre-impregnated. In order to prevent the base fabrics from adhering to each other during the pre-impregnation process, which affects the pre-impregnation effect of the base fabric, designers After the improvement, during the pre-impregnation process, the staff continued to stir the pre-impregnated base fabrics to prevent the base fabrics from sticking together during the pre-impregnation process.

The pre-impregnation material contains 80 parts of bio-based degradable polyurethane resin, 300 parts of DMF and 5 parts of ultrafine graphene. The preparation requirements of the pre-impregnation material are as follows: firstly add ultrafine graphene and DMF into a vacuum stirring tank at 25°C and stir at 500r/min for 20min, then add bio-based degradable polyurethane resin and stir at 1000r/min for 30min, and then vacuum degassing for 60min. After filtering with 100 meshes, the pre-impregnated working slurry was obtained.

In the process of pre-impregnation, since the base fabric of the bottom embryo was made of cotton-polyester blended knitted fabric, the pre-impregnation effect of the base fabric was poor in the process of pre-impregnation. The staff found that bio-based degradable polyurethane resin, DMF and ultra-fine The coverage of graphene on the base fabric cannot meet the requirements of the next step.

After the improvement, the designer took out the pre-impregnated base fabric from the pool, and then hung several base fabrics in a drying room at 20°C for drying, and the drying time was 5 minutes. After drying the base cloth for 5 minutes, the surface of the base cloth is in a semi-dry state. After the base cloth is dried, the base cloth is taken out from the drying chamber.

A recovery tank is installed in the drying chamber, and the recovery tank is located on the lower side of the base cloth. When the base cloth is hung in the drying chamber, the recovery tank collects the pre-impregnated material, thereby preventing the waste of the pre-impregnated material.

In practice, when the designer twisted the towel, it was found that the water absorption of the towel was poor, and the water absorption of the towel was greatly increased after rubbing. , After the base cloth is taken out from the drying room, the base cloth is placed in the kneading machine, and the base cloth is re-impregnated for 15 minutes after being rubbed in the kneading machine for 3s. The designers found that the effect of pre-impregnation of the base fabric was greatly improved after rubbing.

Step 2:

The coating slurry with biodegradable polyurethane resin is coated on the pre-impregnated base fabric. The coating slurry was 60 parts of bio-based degradable polyurethane resin, 30 parts of polyurethane resin, 100 parts of DMF, 5 parts of carboxymethyl cellulose, 5 parts of ultrafine graphene, 5 parts of ramie fiber powder and 2 parts of calcium gluconate.

The preparation process of the coating slurry is to add ultrafine graphene, ramie fiber powder, carboxymethyl cellulose, calcium gluconate and DMF into a vacuum stirring tank at 500 r/min for 30 min, and then add bio-based degradable polyurethane resin. After stirring at 1000 r/min for 60 min, vacuum defoaming for 60 min, and then filtering with 180 mesh to prepare the coating working slurry for later use.

The base fabric passes through the No. 1 scraper, No. 2 scraper, and No. 3 scraper in turn. The No. 1 scraper, No. 2 scraper, and No. 3 scraper include scrapers No. 1, scraper two, scrapers No. 3 and scraper No. 1 respectively. The distance from the base cloth is 9cm, the distance between the second scraper and the base cloth is 3cm, and the distance between the third scraper and the base cloth is 0.6cm.

In the process of use, if the bio-based degradable polyurethane resin is applied to the base fabric in one step, it will easily lead to the formation of air bubbles. The effect of the bio-based degradable polyurethane resin coating on the base cloth is improved, and the appearance of air bubbles is prevented.

During use, the coating slurry is solvent-based, which leads to a difference in the stability of the coating slurry on the base fabric. After improvement by the designer, it includes the No. 1 heater, the No. 2 heater and the No. 3 heater. And the No. 1 heater, the No. 2 heater, and the No. 3 heater correspond to the No. 1 scraper, the No. 2 scraper, and the No. 3 scraper, respectively.

When in use, the temperature of the No. 1 heater is 20°C, the temperature of the No. 2 heater is 30°C, and the temperature of the No. 3 heater is 40°C, and the No. There is a No. 2 blower, a No. 3 heater is provided with a No. 3 blower, the No. 1 blower faces the No. 1 scraper, the No. 2 blower faces the No. 2 scraper, and the No. 3 blower faces the No. 3 scraper. Since the No. 1 doctor blade thickly coats the coating slurry on the base fabric, the temperature of the No. 1 heater can be adjusted so that the coating slurry does not flow on the base fabric, so as to facilitate the coating of the No. 2 doctor blade. The heating of the base fabric by the No. 1 heater, the No. 2 heater and the No. 3 heater improves the subsequent work efficiency.

third step:

The biodegradable polyurethane resin is solidified on the surface of the base fabric. The specific step of solidification is to perform a cold air drying and solidification process for 1 hour on both sides of the base cloth under the condition of a temperature of 20°C.

the fourth step:

Wash the base cloth with clean water, and wash the DMF on the base cloth. The specific steps of washing the base cloth are as follows: the base cloth passes through the No. 1 pool, the No. 2 pool and the No. 3 pool in sequence at a speed of 0.5m/s, and the base cloth is immersed in the pool when passing through the pool; the No. 1 pool is salt water, Pools No. 2 and No. 3 are clean water.

It should be noted that the base cloth impregnated with the slurry is continuously conveyed by setting a power roller device, and the whole device is arranged directly above all the pools, and since the first pool, the second pool, and the third pool are separated from each other , when the base cloth is running under a certain power, the whole is wavy, the base cloth between each two power rollers is in the shape of an arc, the base cloth is located at the bottom of the arc shape and immersed in the pool, The time is determined according to the running speed of the power roller, and the movement mode of the power roller can also adopt regular intermittent motion. The duration of each movement is longer than the static duration, so that the base fabric can be relatively extended in the pool after each change of position. The time of immersion in the medium is increased to improve the removal effect of DMF in the base fabric.

Moreover, because the base cloth is in the shape of an arc, the DMF in the base cloth will gradually gather at the bottom of the arc under the action of gravity due to the existence of the inclined angle of the base cloth immersed in the pool, which is convenient for the solution and DMF in the pool to be sufficient. mix.

Each time the power roller runs, the width of the base fabric immersed in the pool is the same. The width can be controlled by setting the running speed and running time of the power roller. For optimization, the base fabric is immersed in the water surface along the running direction. Symmetrical planes are set symmetrically. The length of the width submerged in the pool is called the lower half arc, and the length of the width exposed on the water surface is called the upper half arc. For example, after each operation, the upper half arc is exposed on the water surface. After that, it will switch to being immersed in the pool, which is the lower half of the arc, so set up, when a lower half of the arc is cleaned in the first pool for the first time, it emerges from the first pool and becomes the upper half of the arc. , and then transformed into the lower half arc section into the second pool for the second cleaning, the same can be obtained, and then the same lower half arc section enters the third pool for the third cleaning. In this way, the entire base fabric is divided into multiple upper or lower arc segments with the same length. DMF in the base fabric can be cleaned when it is in the lower half arc, and can be cleaned in the upper half arc. Under the action of gravity, the DMF in the base fabric is collected in the lower half arc, and all the base fabrics can be fully washed with water for many times, which improves the removal efficiency of DMF in the base fabric.

Moreover, the advantage of this water washing method is that when the base fabric gradually leaves the pool during the running process, since it is about to ascend, the base fabric is inclined at this time, and the water will fall under the action of gravity. Since DMF can dissolve in water, the internal The residual DMF will be separated from the base cloth with the water under the action of gravity, which can better improve the removal effect of DMF in the base cloth.

In summary, reasonable adjustment of the working parameters of the power roller and the running state of the layout base fabric can make the base fabric perform continuous multiple cleanings, and it is precisely because of this that the DMF removal effect of the base fabric is the best.

the fifth step:

Preheating, ironing, drying and shaping at 120°C to obtain the bottom embryo, the time for ironing the base fabric is 3min, the temperature for drying the base fabric is 160°C, and the drying time for the base fabric is 8min. The temperature is 160°C and the time is 9s.

Step 6:

The solvent-based biodegradable polyurethane resin is coated and scraped on the release paper, and then the release paper coated with the biodegradable polyurethane resin is placed in an oven and heated to form a film.

The step of coating and scraping the bio-based degradable polyurethane resin on the release paper is as follows: including a coating roller, a first leveling roller and a second leveling roller arranged opposite to each other, and the release paper is driven at a speed of 0.3m/s. Passing between two oppositely arranged coating rollers, passing through two oppositely arranged first leveling rollers at a speed of 0.2 m/s, and passing through two oppositely arranged second leveling rollers at a speed of 0.1 m/s.

When in use, adjust the distance between the two coating rollers to 1.2cm, the distance between the two first leveling rollers to 0.7cm, and the distance between the two second leveling rollers to 0.3cm. The coating roller, the first leveling roller and the second leveling roller scrape the bio-based degradable polyurethane resin on the release paper, so that the effect of the bio-based degradable polyurethane resin on the release paper is improved.

During the coating and scraping process of the coating roller, the bio-based degradable polyurethane resin is adsorbed on the coating roller from the barrel, and the surfaces of the first leveling roller and the second leveling roller are coated with anti-stick coating to prevent the second leveling roller. When the first leveling roller and the second leveling roller are leveling the bio-based degradable polyurethane resin on the surface of the release paper, the bio-based degradable polyurethane resin adheres to the first leveling roller and the second leveling roller.

The film and the bottom embryo are laminated, and then dried, and the temperature of drying the film and the bottom embryo is 70° C., and finally a finished product is obtained.

To test the surface integrity of semi-finished synthetic leather, method 1: use carbon 12 isotope method to determine the content of organic substances greater than 35%; method 2: use fluorescence spectrometer to determine that the content of heavy metals is lower than the EU standard; method 3: use gas image liquid mass spectrometer Determination of DMF content is lower than the EU standard; Method 4: Use the jungle test method to determine the 14-day aging resistance without damage. Finally, the qualified finished synthetic leather is rolled up.

Example 2:

Synthetic leather is a plastic product that simulates the composition and structure of natural leather and can be used as a substitute material. During the preparation process of synthetic leather, the impregnated non-woven fabric is usually used as the mesh layer, and the microporous polyurethane layer is used as the mesh layer. Grain layer obtained. After the designer's improvement, the base fabric of the synthetic leather veneer product is a cotton-polyester blended knitted fabric.

The preparation steps of the synthetic leather veneer finished product are:

first step:

Pre-impregnating the base fabric, in order to improve the effect of pre-impregnation of the base fabric, the temperature of pre-impregnation is 55 ℃, and the time of pre-impregnation is 4h, so that the effect of the base fabric during pre-impregnation is greatly improved. During the pre-impregnation process of the base fabric, more base fabrics are often pre-impregnated. In order to prevent the base fabrics from adhering to each other during the pre-impregnation process, which affects the pre-impregnation effect of the base fabric, designers After the improvement, during the pre-impregnation process, the staff continued to stir the pre-impregnated base fabrics to prevent the base fabrics from sticking together during the pre-impregnation process.

The pre-impregnation material contains 90 parts of bio-based degradable polyurethane resin, 350 parts of DMF and 7.5 parts of ultra-fine graphene. The preparation requirements of the pre-impregnation material are as follows: firstly add ultra-fine graphene and DMF into a vacuum stirring tank at 27.5 °C and stir at 650r/min for 25min, then add biodegradable polyurethane resin at 1250r/min and stir for 35min, and then vacuum degassing for 90min. After filtering with 100 meshes, the pre-impregnated working slurry was obtained.

In the process of pre-impregnation, since the base fabric of the bottom embryo was made of cotton-polyester blended knitted fabric, the pre-impregnation effect of the base fabric was poor in the process of pre-impregnation. The staff found that bio-based degradable polyurethane resin, DMF and ultra-fine The coverage of graphene on the base fabric cannot meet the requirements of the next step.

After the improvement, the designer took out the pre-impregnated base fabric from the pool, and then hung several base fabrics in a drying room at 25°C for drying, and the drying time was 6 minutes. After drying the base cloth for 6 minutes, the surface of the base cloth is in a semi-dry state. After the base cloth is dried, the base cloth is taken out from the drying chamber.

A recovery tank is installed in the drying chamber, and the recovery tank is located on the lower side of the base cloth. When the base cloth is hung in the drying chamber, the recovery tank collects the pre-impregnated material, thereby preventing the waste of the pre-impregnated material.

In practice, when the designer twisted the towel, it was found that the water absorption of the towel was poor, and the water absorption of the towel was greatly increased after rubbing. , After the base cloth is taken out from the drying room, the base cloth is placed in the kneading machine, and the base cloth is re-impregnated for 17.5 minutes after being rubbed in the kneading machine for 4s. The designers found that the effect of pre-impregnation of the base fabric was greatly improved after rubbing.

Step 2:

The coating slurry with biodegradable polyurethane resin is coated on the pre-impregnated base fabric. The coating slurry is 65 parts of biodegradable polyurethane resin, 35 parts of polyurethane resin, 100 parts of DMF, 7.5 parts of carboxymethyl cellulose, 7.5 parts of ultrafine graphene, 7.5 parts of ramie fiber powder and 3.5 parts of calcium gluconate.

The preparation process of the coating slurry is as follows: firstly, adding ultrafine graphene, ramie fiber powder, carboxymethyl cellulose, calcium gluconate and DMF into a vacuum stirring tank and stirring at 650r/min for 30min, and then adding biodegradable polyurethane resin to After stirring at 1250 r/min for 90 min, vacuum defoaming for 90 min, filtering with 190 mesh to prepare the coating working slurry for later use.

The base fabric passes through the No. 1 scraper, No. 2 scraper, and No. 3 scraper in turn. The No. 1 scraper, No. 2 scraper, and No. 3 scraper include scrapers No. 1, scraper two, scrapers No. 3 and scraper No. 1 respectively. The distance from the base cloth is 8cm, the distance between the second scraper and the base cloth is 2cm, and the distance between the third scraper and the base cloth is 0.4cm.

In the process of use, if the bio-based degradable polyurethane resin is applied to the base fabric in one step, it will easily lead to the formation of air bubbles. The effect of the bio-based degradable polyurethane resin coating on the base cloth is improved, and the appearance of air bubbles is prevented.

During use, the coating slurry is solvent-based, which leads to a difference in the stability of the coating slurry on the base fabric. After improvement by the designer, it includes the No. 1 heater, the No. 2 heater and the No. 3 heater. And the No. 1 heater, the No. 2 heater, and the No. 3 heater correspond to the No. 1 scraper, the No. 2 scraper, and the No. 3 scraper, respectively.

When in use, the temperature of the No. 1 heater is 25°C, the temperature of the No. 2 heater is 35°C, and the temperature of the No. 3 heater is 45°C, and the No. 1 heater is provided with a No. 1 blower and the No. 2 heater is set There is a No. 2 blower, a No. 3 heater is provided with a No. 3 blower, the No. 1 blower faces the No. 1 scraper, the No. 2 blower faces the No. 2 scraper, and the No. 3 blower faces the No. 3 scraper. Since the No. 1 doctor blade thickly coats the coating slurry on the base fabric, the temperature of the No. 1 heater can be adjusted so that the coating slurry does not flow on the base fabric, so as to facilitate the coating of the No. 2 doctor blade. The heating of the base fabric by the No. 1 heater, the No. 2 heater and the No. 3 heater improves the subsequent work efficiency.

third step:

The biodegradable polyurethane resin is solidified on the surface of the base fabric. The specific step of solidification is to perform a cold air drying and solidification process for 1 hour on both sides of the base cloth under the condition of a temperature of 20°C.

the fourth step:

Wash the base cloth with clean water, and wash the DMF on the base cloth. The specific steps of washing the base cloth are as follows: the base cloth passes through the No. 1 pool, the No. 2 pool and the No. 3 pool in sequence at a speed of 0.5m/s, and the base cloth is immersed in the pool when passing through the pool; the No. 1 pool is salt water, Pools No. 2 and No. 3 are clean water.

It should be noted that the base cloth impregnated with the slurry is continuously conveyed by setting a power roller device, and the whole device is arranged directly above all the pools, and since the first pool, the second pool, and the third pool are separated from each other , when the base cloth is running under a certain power, the whole is wavy, the base cloth between each two power rollers is in the shape of an arc, the base cloth is located at the bottom of the arc shape and immersed in the pool, The time is determined according to the running speed of the power roller, and the movement mode of the power roller can also adopt regular intermittent motion. The duration of each movement is longer than the static duration, so that the base fabric can be relatively extended in the pool after each change of position. The time of immersion in the medium is increased to improve the removal effect of DMF in the base fabric.

Moreover, because the base cloth is in the shape of an arc, the DMF in the base cloth will gradually gather at the bottom of the arc under the action of gravity due to the existence of the inclined angle of the base cloth immersed in the pool, which is convenient for the solution and DMF in the pool to be sufficient. mix.

Each time the power roller runs, the width of the base fabric immersed in the pool is the same. The width can be controlled by setting the running speed and running time of the power roller. For optimization, the base fabric is immersed in the water surface along the running direction. Symmetrical planes are set symmetrically. The length of the width submerged in the pool is called the lower half arc, and the length of the width exposed on the water surface is called the upper half arc. For example, after each operation, the upper half arc is exposed on the water surface. After that, it will switch to being immersed in the pool, which is the lower half of the arc, so set up, when a lower half of the arc is cleaned in the first pool for the first time, it emerges from the first pool and becomes the upper half of the arc. , and then transformed into the lower half arc section into the second pool for the second cleaning, the same can be obtained, and then the same lower half arc section enters the third pool for the third cleaning. In this way, the entire base fabric is divided into multiple upper or lower arc segments with the same length. DMF in the base fabric can be cleaned when it is in the lower half arc, and can be cleaned in the upper half arc. Under the action of gravity, the DMF in the base fabric is collected in the lower half arc, and all the base fabrics can be fully washed with water for many times, which improves the removal efficiency of DMF in the base fabric.

Moreover, the advantage of this water washing method is that when the base fabric gradually leaves the pool during the running process, since it is about to ascend, the base fabric is inclined at this time, and the water will fall under the action of gravity. Since DMF can dissolve in water, the internal The residual DMF will be separated from the base cloth with the water under the action of gravity, which can better improve the removal effect of DMF in the base cloth.

In summary, reasonable adjustment of the working parameters of the power roller and the running state of the layout base fabric can make the base fabric perform continuous multiple cleanings, and it is precisely because of this that the DMF removal effect of the base fabric is the best.

the fifth step:

Preheating, ironing, drying and shaping at 120°C to obtain the bottom embryo, the time for ironing the base fabric is 3min, the temperature for drying the base fabric is 160°C, and the drying time for the base fabric is 8min. The temperature is 160°C and the time is 9s.

Step 6:

The solvent-based biodegradable polyurethane resin is coated and scraped on the release paper, and then the release paper coated with the biodegradable polyurethane resin is placed in an oven and heated to form a film.

The step of coating and scraping the bio-based degradable polyurethane resin on the release paper is as follows: including a coating roller, a first leveling roller and a second leveling roller arranged opposite to each other, and the release paper is driven at a speed of 0.3m/s. Passing between two oppositely arranged coating rollers, passing through two oppositely arranged first leveling rollers at a speed of 0.2 m/s, and passing through two oppositely arranged second leveling rollers at a speed of 0.1 m/s.

When in use, adjust the distance between the two coating rollers to 1.2cm, the distance between the two first leveling rollers to 0.7cm, and the distance between the two second leveling rollers to 0.3cm. The coating roller, the first leveling roller and the second leveling roller scrape the bio-based degradable polyurethane resin on the release paper, so that the effect of the bio-based degradable polyurethane resin on the release paper is improved.

During the coating and scraping process of the coating roller, the bio-based degradable polyurethane resin is adsorbed on the coating roller from the barrel, and the surfaces of the first leveling roller and the second leveling roller are coated with anti-stick coating to prevent the second leveling roller. When the first leveling roller and the second leveling roller are leveling the bio-based degradable polyurethane resin on the surface of the release paper, the bio-based degradable polyurethane resin adheres to the first leveling roller and the second leveling roller.

The film and the bottom embryo are laminated, and then dried, and the temperature of drying the film and the bottom embryo is 70° C., and finally a finished product is obtained.

To test the surface integrity of semi-finished synthetic leather, method 1: use carbon 12 isotope method to determine the content of organic substances greater than 35%; method 2: use fluorescence spectrometer to determine that the content of heavy metals is lower than the EU standard; method 3: use gas image liquid mass spectrometer Determination of DMF content is lower than the EU standard; Method 4: Use the jungle test method to determine the 14-day aging resistance without damage. Finally, the qualified finished synthetic leather is rolled up.

Example 3:

Synthetic leather is a plastic product that simulates the composition and structure of natural leather and can be used as a substitute material. During the preparation process of synthetic leather, the impregnated non-woven fabric is usually used as the mesh layer, and the microporous polyurethane layer is used as the mesh layer. Grain layer obtained. After the designer's improvement, the base fabric of the synthetic leather veneer product is a cotton-polyester blended knitted fabric.

The preparation steps of the synthetic leather veneer finished product are:

first step:

To pre-impregnate the base fabric, in order to improve the effect of pre-impregnation of the base fabric, the temperature of pre-impregnation is 60 °C, and the time of pre-impregnation is 5 h, so that the effect of pre-impregnation of the base fabric is greatly improved. During the pre-impregnation process of the base fabric, more base fabrics are often pre-impregnated. In order to prevent the base fabrics from adhering to each other during the pre-impregnation process, which affects the pre-impregnation effect of the base fabric, designers After the improvement, during the pre-impregnation process, the staff continued to stir the pre-impregnated base fabrics to prevent the base fabrics from sticking together during the pre-impregnation process.

The pre-impregnation material contains 100 parts of bio-based degradable polyurethane resin, 400 parts of DMF and 10 parts of ultra-fine graphene. The preparation requirements of the pre-impregnation material are as follows: firstly add the ultrafine graphene and DMF into the vacuum stirring tank at 30°C and stir at 800r/min for 30min, then add bio-based degradable polyurethane resin at 1500r/min and stir for 40min, and then vacuum degassing for 120min. After filtering with 100 meshes, the pre-impregnated working slurry was obtained.

In the process of pre-impregnation, since the base fabric of the bottom embryo was made of cotton-polyester blended knitted fabric, the pre-impregnation effect of the base fabric was poor in the process of pre-impregnation. The staff found that bio-based degradable polyurethane resin, DMF and ultra-fine The coverage of graphene on the base fabric cannot meet the requirements of the next step.

After the improvement, the designer took out the pre-impregnated base fabric from the pool, and then hung several base fabrics in a drying room at 30°C for drying treatment, and the drying time was 7 minutes. After drying the base cloth for 7 minutes, the surface of the base cloth is in a semi-dry state. After the base cloth is dried, the base cloth is taken out from the drying chamber.

A recovery tank is installed in the drying chamber, and the recovery tank is located on the lower side of the base cloth. When the base cloth is hung in the drying chamber, the recovery tank collects the pre-impregnated material, thereby preventing the waste of the pre-impregnated material.

In practice, when the designer twisted the towel, it was found that the water absorption of the towel was poor, and the water absorption of the towel was greatly increased after rubbing. , After the base cloth is taken out from the drying room, the base cloth is placed in the kneading machine, and the base cloth is re-impregnated for 20 minutes after being rubbed in the kneading machine for 5s. The designers found that the effect of pre-impregnation of the base fabric was greatly improved after rubbing.

Step 2:

The coating slurry with biodegradable polyurethane resin is coated on the pre-impregnated base fabric. The coating slurry is 70 parts of bio-based degradable polyurethane resin, 40 parts of polyurethane resin, 100 parts of DMF, 10 parts of carboxymethyl cellulose, 10 parts of ultrafine graphene, 10 parts of ramie fiber powder and 5 parts of calcium gluconate.

The preparation process of the coating slurry is to add ultrafine graphene, ramie fiber powder, carboxymethyl cellulose, calcium gluconate and DMF into a vacuum stirring tank at 800r/min for 30min, and then add biodegradable polyurethane resin to After stirring at 1500 r/min for 120 min, vacuum defoaming for 120 min, and then filtering with 200 mesh to prepare the coating working slurry for later use.

The base fabric passes through the No. 1 scraper, No. 2 scraper, and No. 3 scraper in turn. The No. 1 scraper, No. 2 scraper, and No. 3 scraper include scrapers No. 1, scraper two, scrapers No. 3 and scraper No. 1 respectively. The distance from the base cloth is 7cm, the distance between the second scraper and the base cloth is 1cm, and the distance between the third scraper and the base cloth is 0.2cm.

In the process of use, if the bio-based degradable polyurethane resin is applied to the base fabric in one step, it will easily lead to the formation of air bubbles. The effect of the bio-based degradable polyurethane resin coating on the base cloth is improved, and the appearance of air bubbles is prevented.

During use, the coating slurry is solvent-based, which leads to a difference in the stability of the coating slurry on the base fabric. After improvement by the designer, it includes the No. 1 heater, the No. 2 heater and the No. 3 heater. And the No. 1 heater, the No. 2 heater, and the No. 3 heater correspond to the No. 1 scraper, the No. 2 scraper, and the No. 3 scraper, respectively.

When in use, the temperature of the No. 1 heater is 30°C, the temperature of the No. 2 heater is 40°C, and the temperature of the No. 3 heater is 50°C, and the No. There is a No. 2 blower, a No. 3 heater is provided with a No. 3 blower, the No. 1 blower faces the No. 1 scraper, the No. 2 blower faces the No. 2 scraper, and the No. 3 blower faces the No. 3 scraper. Since the No. 1 doctor blade thickly coats the coating slurry on the base fabric, the temperature of the No. 1 heater can be adjusted so that the coating slurry does not flow on the base fabric, so as to facilitate the coating of the No. 2 doctor blade. The heating of the base fabric by the No. 1 heater, the No. 2 heater and the No. 3 heater improves the subsequent work efficiency.

third step:

The biodegradable polyurethane resin is solidified on the surface of the base fabric. The specific step of solidification is to perform a cold air drying and solidification process for 1 hour on both sides of the base cloth under the condition of a temperature of 20°C.

the fourth step:

Wash the base cloth with clean water, and wash the DMF on the base cloth. The specific steps of washing the base cloth are as follows: the base cloth passes through the No. 1 pool, the No. 2 pool and the No. 3 pool in sequence at a speed of 0.5m/s, and the base cloth is immersed in the pool when passing through the pool; the No. 1 pool is salt water, Pools No. 2 and No. 3 are clean water.

It should be noted that the base cloth impregnated with the slurry is continuously conveyed by setting a power roller device, and the whole device is arranged directly above all the pools, and since the first pool, the second pool, and the third pool are separated from each other , when the base cloth is running under a certain power, the whole is wavy, the base cloth between each two power rollers is in the shape of an arc, the base cloth is located at the bottom of the arc shape and immersed in the pool, The time is determined according to the running speed of the power roller, and the movement mode of the power roller can also adopt regular intermittent motion. The duration of each movement is longer than the static duration, so that the base fabric can be relatively extended in the pool after each change of position. The time of immersion in the medium is increased to improve the removal effect of DMF in the base fabric.

Moreover, because the base cloth is in the shape of an arc, the DMF in the base cloth will gradually gather at the bottom of the arc under the action of gravity due to the existence of the inclined angle of the base cloth immersed in the pool, which is convenient for the solution and DMF in the pool to be sufficient. mix.

Each time the power roller runs, the width of the base fabric immersed in the pool is the same. The width can be controlled by setting the running speed and running time of the power roller. For optimization, the base fabric is immersed in the water surface along the running direction. Symmetrical planes are set symmetrically. The length of the width submerged in the pool is called the lower half arc, and the length of the width exposed on the water surface is called the upper half arc. For example, after each operation, the upper half arc is exposed on the water surface. After that, it will switch to being immersed in the pool, which is the lower half of the arc, so set up, when a lower half of the arc is cleaned in the first pool for the first time, it emerges from the first pool and becomes the upper half of the arc. , and then transformed into the lower half arc section into the second pool for the second cleaning, the same can be obtained, and then the same lower half arc section enters the third pool for the third cleaning. In this way, the entire base fabric is divided into multiple upper or lower arc segments with the same length. DMF in the base fabric can be cleaned when it is in the lower half arc, and can be cleaned in the upper half arc. Under the action of gravity, the DMF in the base fabric is collected in the lower half arc, and all the base fabrics can be fully washed with water for many times, which improves the removal efficiency of DMF in the base fabric.

Moreover, the advantage of this water washing method is that when the base fabric gradually leaves the pool during the running process, since it is about to ascend, the base fabric is inclined at this time, and the water will fall under the action of gravity. Since DMF can dissolve in water, the internal The residual DMF will be separated from the base cloth with the water under the action of gravity, which can better improve the removal effect of DMF in the base cloth.

In summary, reasonable adjustment of the working parameters of the power roller and the running state of the layout base fabric can make the base fabric perform continuous multiple cleanings, and it is precisely because of this that the DMF removal effect of the base fabric is the best.

the fifth step:

Preheating, ironing, drying and shaping at 120°C to obtain the bottom embryo, the time for ironing the base fabric is 3min, the temperature for drying the base fabric is 160°C, and the drying time for the base fabric is 8min. The temperature was 160°C and the time was 9s.

Step 6:

The solvent-based biodegradable polyurethane resin is coated and scraped on the release paper, and then the release paper coated with the biodegradable polyurethane resin is placed in an oven and heated to form a film.

The step of coating and scraping the bio-based degradable polyurethane resin on the release paper is as follows: including a coating roller, a first leveling roller and a second leveling roller arranged opposite to each other, and the release paper is driven at a speed of 0.3m/s. Passing between two oppositely arranged coating rollers, passing through two oppositely arranged first leveling rollers at a speed of 0.2 m/s, and passing through two oppositely arranged second leveling rollers at a speed of 0.1 m/s.

When in use, adjust the distance between the two coating rollers to 1.2cm, the distance between the two first leveling rollers to 0.7cm, and the distance between the two second leveling rollers to 0.3cm. The coating roller, the first leveling roller and the second leveling roller scrape the bio-based degradable polyurethane resin on the release paper, so that the effect of the bio-based degradable polyurethane resin on the release paper is improved.

During the coating and scraping process of the coating roller, the bio-based degradable polyurethane resin is adsorbed on the coating roller from the barrel, and the surfaces of the first leveling roller and the second leveling roller are coated with anti-stick coating to prevent the second leveling roller. When the first leveling roller and the second leveling roller are leveling the bio-based degradable polyurethane resin on the surface of the release paper, the bio-based degradable polyurethane resin adheres to the first leveling roller and the second leveling roller.

The film and the bottom embryo are laminated, and then dried, and the temperature of drying the film and the bottom embryo is 70° C., and finally a finished product is obtained.

To test the surface integrity of semi-finished synthetic leather, method 1: use carbon 12 isotope method to determine the content of organic substances greater than 35%; method 2: use fluorescence spectrometer to determine that the content of heavy metals is lower than the EU standard; method 3: use gas image liquid mass spectrometer Determination of DMF content is lower than the EU standard; Method 4: Use the jungle test method to determine the 14-day aging resistance without damage. Finally, the qualified finished synthetic leather is rolled up.

The above are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore: all equivalent changes made according to the structure, shape and principle of the present application should be covered within the scope of the present application. Inside.

Claims (10)

1. A bio-based degradable finished product containing dip-coating and scraping knitted fabric polyurethane synthetic leather veneering is characterized in that: the base cloth of the finished synthetic leather veneering product is a cotton-polyester blended knitted fabric;

the preparation steps of the synthetic leather veneered finished product are as follows:

the first step is as follows: pre-impregnating the base cloth, wherein the pre-impregnated material comprises bio-based degradable polyurethane resin, DMF (dimethyl formamide) and ultrafine graphene;

the second step is that: coating on the pre-impregnated base fabric, wherein the coating material comprises biodegradable polyurethane resin;

the third step: solidifying the bio-based degradable polyurethane resin on the surface of the base fabric;

the fourth step: washing the base cloth with clean water, and washing DMF on the base cloth;

the fifth step: preheating, ironing, drying and shaping the base cloth to obtain a base blank;

and a sixth step: coating and scraping the solvent type bio-based degradable polyurethane resin on release paper, then putting the release paper into an oven to heat to form a thin film, then attaching the thin film to the base blank, and finally drying to obtain a finished product;

the pre-impregnation material comprises 80-100 parts of bio-based degradable polyurethane resin, 300-400 parts of DMF (dimethyl formamide) and 5-10 parts of ultrafine graphene;

the coating slurry is composed of 60-70 parts of bio-based degradable polyurethane resin, 30-40 parts of polyurethane resin, 100 parts of DMF (dimethyl formamide), 5-10 parts of carboxymethyl cellulose, 5-10 parts of superfine graphene, 5-10 parts of ramie fiber powder and 2-5 parts of calcium gluconate.

2. The finished product of the bio-based degradable polyurethane synthetic leather veneering containing dip-coating and scratch-knitted fabric according to claim 1, which is characterized in that: the preparation requirement of the pre-impregnation material is that the superfine graphene and DMF are firstly added into a vacuum stirring kettle and stirred for 20-30min at 25-30 ℃ at 800r/min, then the bio-based degradable polyurethane resin is added and stirred for 30-40min at 1500r/min, vacuum defoaming is carried out for 60-120min, and then 100 meshes of filtration is carried out to prepare the pre-impregnation working slurry.

3. The finished product of the bio-based degradable polyurethane synthetic leather veneering containing dip-coating and scratch-knitted fabric according to claim 1, which is characterized in that: the preparation process of the coating slurry comprises the steps of firstly adding the ultrafine graphene, the ramie fiber powder, the carboxymethyl cellulose, the calcium gluconate and the DMF into a vacuum stirring kettle, stirring for 30min at 800r/min under the condition of 500 plus materials, then adding the bio-based degradable polyurethane resin, stirring for 60-120min under the condition of 1000 plus materials and 1500r/min, defoaming for 60-120min under the condition of vacuum, and filtering with 200-mesh plus materials under the condition of 180 plus materials to prepare the coating working slurry for later use.

4. The finished product of the bio-based degradable polyurethane synthetic leather veneering containing dip-coating and scratch-knitted fabric according to claim 1, which is characterized in that: in the first step, the temperature of pre-impregnation is 50-60 ℃, and the time of pre-impregnation is 3-5 h; and in the process of pre-impregnation, continuously stirring the pre-impregnated base cloth.

5. The bio-based degradable dip-coated and scratch-coated knitted fabric-containing polyurethane synthetic leather veneered finished product of claim 1 is characterized in that: in the first step, taking out the pre-impregnated base cloth from the pool, then hanging the base cloth in a drying chamber at 20-30 ℃ for 5-7min, wherein a recovery tank is arranged in the drying chamber and positioned at the lower side of the base cloth, and the recovery tank collects the pre-impregnated material; and taking the base cloth out of the drying chamber after the airing is finished, putting the base cloth into a rubbing machine after the base cloth is taken out of the drying chamber, and pre-soaking the base cloth for 15-20min after the base cloth is rubbed below the temperature in the rubbing machine for 3-5 s.

6. The finished product of the bio-based degradable polyurethane synthetic leather veneering containing dip-coating and scratch-knitted fabric according to claim 1, which is characterized in that: in the second step, the base cloth passes through a scraper, a second scraper and a third scraper in sequence, the first scraper, the second scraper and the third scraper are respectively arranged on the first scraper, the second scraper and the third scraper, the distance between the first scraper and the base cloth is 7-9cm, the distance between the second scraper and the base cloth is 1-3cm, and the distance between the third scraper and the base cloth is 0.2-0.6 cm.

7. The finished product of the bio-based degradable polyurethane synthetic leather veneering containing dip-coated and scratch-knitted fabric according to claim 6, which is characterized in that: the second step comprises a first heater, a second heater and a third heater, wherein the first heater, the second heater and the third heater respectively correspond to the first scraper, the second scraper and the third scraper, the temperature of the first heater is 20-30 ℃, the temperature of the second heater is 30-40 ℃, the temperature of the third heater is 40-50 ℃, a first air feeder is arranged on the first heater, a second air feeder is arranged on the second heater, a third air feeder is arranged on the third heater, the first air feeder faces the first scraper, the second air feeder faces the second scraper, and the third air feeder faces the third scraper.

8. The finished product of the bio-based degradable polyurethane synthetic leather veneering containing dip-coating and scratch-knitted fabric according to claim 1, which is characterized in that: in the fourth step, the concrete step of washing the base cloth with water is that the base cloth passes through a first water pool, a second water pool and a third water pool in sequence at the movement speed of 0.5m/s, and the base cloth is immersed in the water pools when passing through the water pools; the first water pool is saline solution, and the second water pool and the third water pool are both clear water.

9. The finished product of the bio-based degradable polyurethane synthetic leather veneering containing dip-coating and scratch-knitted fabric according to claim 1, which is characterized in that: in the fifth step, the time for ironing the base cloth is 1-3min, the temperature for drying the base cloth is 120-160 ℃, the drying time of the base cloth is 4-8min, the temperature for shaping the base cloth is 120-160 ℃, and the time is 5-9 s.

10. The finished product of the bio-based degradable polyurethane synthetic leather veneering containing dip-coating and scratch-knitted fabric according to claim 1, which is characterized in that: in the sixth step, the coating roll, the first leveling roll and the second leveling roll are arranged in pairs, the release paper passes between the two coating rolls at the speed of 0.3m/s, passes through the two first leveling rolls at the speed of 0.2m/s and passes through the two second leveling rolls at the speed of 0.1 m/s; the coating roller is adsorbed with bio-based degradable polyurethane resin, and anti-sticking coating is coated on the surfaces of the first spreading roller and the second spreading roller.