KR102003648B1 - Method for manufacturing a bio-pad with improved bulk and bio-pad manufactured by the method - Google Patents

Abstract

The present invention relates to a manufacturing method of a bio pad with an improved bulk and a bio pad manufactured thereby, and more specifically, to a manufacturing method of a bio pad with an improved bulk, which efficiently increases a bulk of a product through a low polarity solvent wetting of a solvent circulation method when a bio pad of a sheet-type structure is manufactured by natural vegetable fibers such as wood pulp, recycled pump, biomass fibers and the like, and to a bio pad manufactured thereby. According to the present invention, the manufacturing method of a bio pad with an improved bulk comprises: a raw material dissociation step of mixing a raw material fiber with water and dissociating the same; a wet web molding and vacuum dehydrating step of molding the dissociated raw material fiber as a wet web and vacuum dehydrating the same; a solvent wetting process step of injecting a mixing solvent mixed with a low polarity solvent and water to the vacuum dehydrated wet web, and substituting moisture contained in the wet web to a low polarity solvent; a vacuum dehydrating step of dehydrating the solvent wetting processed wet web in a vacuum state; and a drying step of drying the vacuum dehydrated wet web at a predetermined temperature.

Description

[0001] The present invention relates to a method of manufacturing a bio-pad having improved bulk and a method of manufacturing the same,

The present invention relates to a method of manufacturing a bio pad with improved bulk and a method of manufacturing the same. More particularly, the present invention relates to a bio pad, which is a sheet-like structure, made of natural vegetable fibers such as wood pulp, recycled pulp and biomass fiber The present invention relates to a method of manufacturing a bio-pad improved in bulk and capable of effectively increasing the bulk of a product through a solvent circulation-type low-polarity solvent wetting process.

Recycling and reuse of wastes are becoming more and more important issues worldwide due to increased concern about global environment and increased concern about safety due to pollution of household garbage.

In particular, the wastes of the degradable polymer-based wastes are not decomposed after disposal, resulting in persistent pollution of the global environment, and their use and utilization are now restricted to a higher level in many countries.

As a result, there is a growing demand for biodegradable, environmentally friendly products and materials that can replace plastic-based products. As biomass, including wood, as a disposable product for various packaging materials, disposable hygiene products, The use of fibers is increasing significantly.

Products based on biomass fibers such as diapers, absorbent cores of absorbent pads and various filter materials, including existing paper products such as paper and paper and cushioning packaging materials, are being used for various purposes. The development of quality enhancement and functionalization technology to replace the products is continuously being carried out.

Mass production of biomass products having a sheet form of biomass fiber is mainly achieved by dispersing physically and chemically dissociated individual biomass fibers in water and forming them into sheets by dewatering or vacuum dewatering method on a mesh of a certain size do.

In the case of the formed wet paper fill, vacuum dewatering or pressurized dehydration is carried out for further dewatering and dried at 100 ° C or higher to produce a biopad sheet.

In the case of paper products, since high-speed mass production is mainly used, the thickness of the product that can be produced is limited, and since the product must be dried within a short time at a high operating speed, it is necessary to apply high- And it is difficult to produce high-grade products.

In the case of high-basis paper products with a basis weight of 200 g / ㎡ or more, many sheets are manufactured in a laminating form, and products such as high-bulk waste paper are subjected to a crating process for high bulking. Only the production of the product is possible. In addition, the method for producing a high-bulk product having a high basis weight such as a cushioning packing material or a filter paper may be a wet pulp mold product in which vacuum dehydration is performed after vacuum forming, It is produced by applying the papermaking method.

Even in the case of such a high-basis product production method, there is a limitation in making high-bulk products due to the chemical properties of natural biomass fibers. Cellulose, which is a main component of biomass fibers, And is characterized in that it has hydrophilicity due to the presence of three hydroxyl groups per glucose molecule.

Natural biomass fibers dispersed and swollen in water form a paper through the forming process and water present between the biomass fiber and the water existing in the pores of the biomass fiber is removed during the process of dehydration and drying. At this time, as the water escapes from the space between the pores and the fibers, the water particles having a very high polarity attract the hydroxyl groups of the adjacent glucose molecules.

As a result, when the water of the wetland fill is completely drained by the dehydration and drying process, the hydroxyl groups of the adjacent glucose molecules drawn by the water are connected to each other to form hydrogen bonds.

In the tributaries and biopads produced by the dehydration and drying process of water, the hydrogen bond formation effect between the biomass fibers can have strong bonding strength without any additional adhesive treatment, but the shrinkage of the biomass fiber itself and the decrease of interfiber pores , There are many difficulties in strengthening the bulk characteristics of the product.

An example of a technique for solving such a problem is described in the following documents 1 to 2.

Patent Document 1 discloses a method for producing a paperboard by forming, laminating, pressurizing, dewatering, drying, processing and glossing a pulp raw material in a paper machine for paper making, comprising the steps of: ) Is mixed with 1 to 10% by weight of a binder resin.

Patent Document 2 discloses a method for separating pulp fibers from a pulp fiber, comprising a dissolving step of diluting the pulp fiber with water, a cleansing step of removing impurities contained in the pulp fiber after the dissolving step, and a cleansing step of softening the pulp fiber after the cleansing step ; A second step of mixing the pulp fiber obtained in the first step with a powdery organic additive composed of at least one selected from wood powder, beer, palm leaf, palm stem, Empty Fruit Bunch (EFB), rice hull, Wherein the powdery organic additive is prepared by sequentially introducing a cationic polymer electrolyte and an anionic polyelectrolyte so as to modify the surface of the polymer electrolyte with a multi-layered polymer electrolyte so as to increase the binding force with the pulp fiber, A method of improving the bulk and strength of a paperboard using the powdery organic additive is disclosed.

However, the conventional techniques as described above have been made by methods of improving the bulk using various additives or additives. Due to limitations in process stability and applicability and quality, the application amount of such additive or additive is limited, Is limited to a low level. Further, in the case of a manufacturing method using an additive or an additive, there is a problem in that it can not be applied to a mass production process due to excessive process time and energy requirement.

Korean Registered Patent No. 10-0954846 (Registered on Apr. 19, 2010) Korean Registered Patent No. 10-1470738 (Registered on December 02, 2014)

Disclosure of Invention Technical Problem [8] The present invention has been conceived to solve the problems as described above, and it is an object of the present invention to provide a biomass fiber- And a method of manufacturing the same, and a method of manufacturing the same, and a method of manufacturing the same, and a method of manufacturing the same, The purpose is to provide.

In order to accomplish the above object, the present invention provides a method for manufacturing a bio-pad improved in bulk, comprising: a raw material dissolving step of mixing raw material fibers into water and dissolving them; A wet paper fill forming and a vacuum dewatering step of forming the dissociated raw material fibers into a wet paper pellet form and vacuum dewatering the same; A solvent wet processing step of spraying a mixed solvent in which a low-polarity solvent and water are mixed to the wet-dewatered vacuum-dehydrated filler, thereby replacing the moisture contained in the wet-matter filter with a low-polarity solvent; A vacuum dewatering step of dewatering the moistened wet filter pellets in a vacuum state; And drying the wet-dewatered vacuum pellet at a predetermined temperature.

The raw material fiber may be any one selected from the group consisting of wood fiber, recycled wastepaper fiber, wood fiber, cotton fiber, high purity cellulose fiber, herbaceous biomass fiber and natural fiber.

In the wet paper fill forming and vacuum dehydrating step, the dissociated raw material fiber is pressurized by a pulp mold forming apparatus, and at the same time, the wet paper is formed by sucking and dewatering with a vacuum pump.

The wet paper fill forming and the vacuum dewatering step may include feeding the dissociated raw material fiber to a paper making machine and dewatering the paper through a net of the paper making machine to form a wet paper fill.

The wet paper peeling and vacuum dewatering step may further include a step of compressing and dewatering the wet paper pellets formed by the paper making machine through a pair of rolls.

Also, the solvent wet processing step may include wet dewatering of the wet paper pellets formed through the wet paper pelletizing and vacuum dewatering steps, wet treatment of the wet paper pellets in the mixed solvent spraying method with the water content of 70 to 80 wt% And the solvent and moisture content of the wet paper pill are in the range of 75 to 90% by weight.

The low polarity solvent may be any one selected from the group consisting of ethyl alcohol, acetone, ethyl acetate (EA) and isopropanol (IPA).

The drying step may include a primary drying step of drying the low-polarity solvent contained in the wet paper; And a second drying step of drying the wet paper to remove moisture remaining in the wet paper after passing through the primary drying step.

Also, the air generated and discharged in the primary drying step is collected, condensed, and re-introduced into the solvent wet processing step.

The bulk improved biopad according to the present invention is characterized in that it is produced by the above production method.

As described above, according to the present invention, a method for manufacturing a bio-pad with enhanced bulk and a method for manufacturing the same, the bio-pad manufactured by using the natural vegetable fiber, Is effectively increased.

In addition, it can be applied directly to the mass production process, and it is possible to apply low polarity solvent at the same speed as the production speed of the existing production process. The low polarity solvent applied to the process is recovered through vacuum dewatering and primary drying process So that the solvent circulation type continuous bulk improvement process can be performed.

In addition, the low-polarity solvent containing ethyl alcohol, which is applied in the present invention, exhibits the effect of sterilization, antibacterial, and eradication, thereby producing a product having excellent hygienic properties.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a process diagram showing a method of manufacturing a bio-pad improved in bulk according to the present invention; FIG.
2 is a block diagram showing a device for manufacturing a bio pad according to a pulp mold method.
3 is a block diagram showing a bio-pad production apparatus according to a paper making method.
4 is a graph showing changes in bulk characteristics due to a wet treatment of a low polarity solvent;
5 is a graph showing an evaluation of change in drying time by the wet treatment.
6 is a graph showing changes in maximum water absorption amount of the biopath according to the wet treatment conditions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, a method of manufacturing a bio-pad improved in bulk according to the present invention includes a raw material dissociation step (S100) in which raw fiber materials are mixed and dissolved in water; A wet paper fill forming and vacuum dewatering step (S200) of forming the dissociated raw material fiber into a wet paper pellet form and vacuum dewatering the same; A solvent wetting step (S300) of spraying a mixed solvent in which the low-polarity solvent and water are mixed to the wet-dewatered vacuum-dehydrated filler, thereby replacing the moisture contained in the wetland fill with a low-polarity solvent; A vacuum dewatering step (S400) of dewatering the wet paper with the solvent wet treatment in a vacuum state; And a drying step (S500) of drying the wet-dewatered wet paper web at a predetermined temperature.

The present invention relates to a bulk enhancement technique that can be directly applied to a mass production method of a biomass based on a wet forming method. The method includes forming the biomass fiber dispersed in water into a sheet form, removing water by a certain amount through vacuum dewatering A low polarity solvent is used to replace the moisture of the wet paper filter with a low polarity solvent. After that, the wet paper filter is squeezed and dehydrated in a vacuum, and dried at a certain temperature to produce a biopad product.

Particularly, the low polarity solvent is composed of any one selected from the group consisting of ethyl alcohol (polarity index: 5.2), acetone (polarity index: 5.1), ethyl acetate (polarity index: 4.4), isopropanol (polarity index: 3.9)

The present invention can be applied directly to the mass production process, and it is possible to apply the low polarity solvent at the same speed as the production rate of the existing production process. The low polarity solvent applied to the process is subjected to the vacuum dehydration and the primary drying process And recovered and recycled, thereby making it possible to perform a solvent circulation type continuous bulk improvement process.

First, in the raw material dissociation step (S100), raw fiber is mixed with water and dissociated.

The raw fiber is dissociated in water using a dissolver, and if necessary, pre-treatment such as cutting or pressing (beating) of the fiber by using a beater is performed.

The dissociation concentration is preferably about 0.5 to 3% so as to facilitate mixing of the raw fiber and water.

The raw material fiber is made of any one selected from the group consisting of wood fiber, recycled woven fiber, wood fiber, cotton fiber, high purity cellulose fiber, herbaceous biomass fiber, and natural fiber.

In the step of mixing and dissolving the raw-material fibers in water, a screen and a cleaner process for removing the raw-fiber impurities can be performed.

That is, fiber raw materials containing impurities that are not usable are not suitable for producing high-quality biopads, and therefore unnecessary impurities are removed through a process such as a screen and a cleaner process.

In the wet paper fill forming and vacuum dewatering step (S200), the dissociated raw material fibers are formed into wet paper pellets and dehydrated in vacuum.

In the wet paper fill forming and vacuum dewatering step (S200), the dissociated raw material fibers are dehydrated under vacuum until the moisture content becomes 80 to 90% by weight.

The wet paper fill forming and vacuum dewatering step (S200) includes pressing the dissociated raw material fiber with a pulp mold forming apparatus (100) and simultaneously drawing a wet paper by suction dewatering with a vacuum pump.

As shown in FIG. 2, in the wet paper fill forming and vacuum dewatering step (S200), the lower mold 120 is contained in the stock solution tank 130, and a certain amount of the stock solution is accommodated in the groove portion of the lower mold. Then, the water contained in the stock solution is sucked by the vacuum pump 140 from the lower mold first, and at the same time, the upper mold 110 is lowered and pressurized to form a wet paper fill.

As another embodiment of the wet paper fill forming method, the wet paper fill forming and vacuum dewatering step (S200) may supply the dissociated raw material fibers to the paper making machine 200, dehydrate the paper through the net of the paper making machine, .

As shown in FIG. 3, the wet puddle is formed on the net by dewatering or vacuum absorbing the stock solution prepared by mixing the water contained in the paper making machine 200 and the raw fiber with a net of a certain size.

The papermaking machine 200 may be configured as a ring-type or papier-type paper machine.

The wet paper fill forming and vacuum dewatering step (S200) further includes a step of compressing and dewatering the wet paper pellets formed by the papermaking machine (200) through the pair of rolls (300). The roll 300 may be a couch roll or a squeeze roll, and may be substituted for the same purpose and effect.

In the solvent wet processing step (S300), a mixed solvent in which a low-polarity solvent and water are mixed is sprayed to the wet-dewatered vacuum pellet, thereby replacing the moisture contained in the wet pellet with a low-polarity solvent.

The solvent wet processing step (S300) may include wet dewatering of the wet paper pellets formed through the wet paper pelletizing and vacuum dewatering steps, wet treatment of the wet paper pellets in the mixed solvent spraying method with the water content of 70-80 wt% Thereby causing the solvent and moisture content of the wet paper to be 75 to 90% by weight.

The low polarity solvent is composed of any one selected from the group consisting of ethyl alcohol, acetone, ethyl acetate (EA) and isopropanol (IPA).

The low-polarity solvent has a polarity lower than that of water and has a relatively weak pulling force for hydroxyl groups, thereby reducing the interfiber adhesion and minimizing the shrinkage and condensation of the fiber itself, thereby greatly improving the bulk of the product.

In the wetting treatment step (S300), the mixed solvent is sprayed directly onto the wet paper pellets to wet the paper with a moisture and solvent content of about 85 to 95%, and further vacuum dehydration is performed so that the solvent and moisture content of the wet paper pell are 75 to 90% So that it is brightly illuminated.

To this end, a solvent spraying device 400 is installed at one side of the pulp molding apparatus 100 or the grass-planting apparatus 200 to spray the mixed solvent onto the surface of the wet paper filter.

Since the solvent spraying method is a method of spraying the mixed solvent onto the surface of the wet paper by using the spray nozzle, the solvent can be sprayed evenly on the surface of the wet paper paper with a small amount of solvent. At this time, the solvent recovered through permeation of the wet paper is recycled and reused as a wet paper treatment solution.

In the vacuum dewatering step (S400), the solvent-wetted wet paper is dewatered in a vacuum state.

The moisture content and the low polarity solvent content of the wet paper filter after the vacuum dewatering step (S400) is about 75 to 85%. The higher the concentration of ethyl alcohol is, the lower the viscosity and the lower the polarity, the higher the dewatering effect becomes.

In the case of the pulp mold method, the water displaced by the low-polarity solvent penetrating into the wet paper filter is dehydrated in the process of further vacuum pressing by the upper and lower molds similar to the wet paper fill forming and vacuum dehydrating steps. At this time, since the pressurized vacuum dewatering is performed on the opposite side of the paper surface to which the low-polarity solvent is applied, the solvent-wetted low-polarity solvent is uniformly absorbed into the wet paper pill of the pulp mold, and at the same time, .

In case of the paper making method, the wet paper is subjected to vacuum dewatering by a vacuum dewatering device after spraying the wet paper, and the mixed solvent is sprayed thereon. Thereafter, the paper is passed through a vacuum dewatering device or roll of the mixed solvent, And some low polarity solvents are dehydrated again.

In the drying step (S500), the vacuum dehydrated wet paper is dried at a predetermined temperature.

The drying step (S500) includes a primary drying step (S510) of drying the low-polarity solvent contained in the wet paper; And a second drying step (S520) of drying the wet paper to remove moisture remaining in the wet paper passing through the primary drying step.

In the case of a low-polarity solvent such as ethyl alcohol (boiling point: 78 ° C), acetone (56 ° C), ethyl acetate (77 ° C) and isopropanol (82 ° C) having a relatively low boiling point, Lt; RTI ID = 0.0 > C, < / RTI >

The present invention includes collecting the air generated and discharged in the primary drying step (S510), condensing it, and re-inputting it to the solvent wet processing step (S300). This is to increase the recovery and reuse efficiency of the solvent evaporated during the first drying.

The secondary drying step (S520) is performed in a water drying apparatus (600) maintained at a temperature of 100 deg. C or more to remove moisture remaining in the wet paper. And the moisture remaining in the wet paper is removed through the secondary drying step to produce a high-bulk biopad.

The water drying apparatus may include a mesh belt or a porous mat having a mesh network in which a plurality of holes are formed, and a heat supply device for supplying heat. As the heat supply device, a microwave, an infrared lamp, a heater, a hot wire, or the like is used, and the device can be substituted for the same purpose and effect.

Meanwhile, in the solvent wet processing step, the vacuum dewatering step, and the primary drying step, a process is performed in a process chamber 700 where the inside is kept in a reduced pressure state in order to minimize the external divergence of the low polarity solvent.

Accordingly, the low polarity solvent is continuously volatilized during the biopad molding process, thereby preventing contamination of the working environment in the process and preventing cost increase due to loss of low polarity solvent.

In the process chamber, a heat supply device is installed on the conveyor side so that heat is radiated to the biopad. A vacuum pump (not shown) is connected to the process chamber to form a reduced pressure state.

Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are illustrative of the present invention, and the present invention is not limited to the following examples.

Example 1: Disclosed material

In the present invention, in order to evaluate the bulk increase effect of the biomass fiber sheet structure by the wet treatment of the low polarity solvent, an experiment was conducted using a hardwood bleached pulp used in various branching products. The bleaching of hardwood bleached pulp was dissociated into fresh water and CSF 600 mL was used. The ethanol solution, which is a typical low-polarity solvent, was used for solvent wetting treatment. Ethanol was mixed with water at a volume ratio of 25 %, 50%, 75%, 99.5%.

Example 2: Biopad manufacturing

A test sheet was prepared by applying a laboratory wet fiber sheet forming machine to produce a fiber sheet. The fiber sheet was diluted with hardwood BKP dissolution to a concentration of 0.05% and subjected to vacuum dehydration under the conditions of a final basis weight of 250 to 300 g / m 2 at 0.04 MPa. For the wet dewatered vacuum dewatered ethanol, a certain amount of ethanol prepared at different concentrations was applied to the entire wetland dewater and vacuum dewatered, so that the ethanol wetted the wet dew point and was sucked into the lower vacuum and removed. After the ethanol wetting treatment, the concentration of the vacuum dewatered wet filter was measured and dried to produce a product. The fabric sheets were treated for 24 hours at room temperature and humidity (23 ± 1 ℃, RH 50%) and analyzed for their characteristics.

Blending condition of solvent type Solvent type water(%) ethanol(%) Control 100 0 A 75 25 B 50 50 C 25 75 D 0.5 99.5

Test Example  One : Low polarity solvent  Bulk property change by wet treatment

The bulk property evaluation of the solvent wetted fiber sheet by the ethanol concentration condition is shown in Fig. The higher the ethanol content of the wetting solvent, the higher the bulk. It was found that as the concentration of ethanol in the wetting solvent increases, the hydrogen bonding between the cellulose is interrupted and the bonding force between the fibers decreases and the bulk increases.

Test Example 2: Evaluation of dry time change by wet treatment

Drying was carried out at 80 ° C to measure and compare moisture contents. The dried water content was adjusted to 100% by weight, the drying was completed, and the level at which the drying was completed was 0% by weight, and the dried amount of the mixed solvent was expressed as a ratio.

As shown in FIG. 5, it was confirmed that the higher the ethanol concentration in the wet treatment, the faster the drying rate was, and when the ethanol concentration was 99% ethanol, about 50% appear.

Particularly, when drying was carried out at 80 ° C, the evaporation of ethyl alcohol in the mixed solvent was all performed, but water remained. The amount of water remaining was evaluated by the solid content of each sample, and the results are shown in Table 2 below.

It can be seen that the solid content of the wet paper pellets produced by applying the mixed solvent to the vacuum dewatered wet paper pellets after the formation and the vacuum dewatering is higher, the higher the ethyl alcohol concentration of the mixed solvent, the higher the polarity of ethyl alcohol is, The vacuum dewatering efficiency is high. After drying at 80 ° C, the residual moisture content was low when a mixed solvent having a high ethyl alcohol concentration was used even after the final drying. In particular, the final solids content varies depending on the ethyl alcohol concentration of the mixed solvent, and the solvent substitution is performed by the actual wet processing method, and the degree of solvent substitution is greatly influenced by the concentration of ethyl alcohol in the solvent .

Therefore, based on the results of this experiment, it was determined that the concentration of ethyl alcohol in the solvent substitution method through the wet treatment method is preferably about 70 to 80%.

Change of Solid Content by Drying at 80 ℃ Sample type Mixed solvent After vacuum dehydration After drying at 80 ℃ Control 10.3 72.7 A 13.2 85.7 B 13.6 87.0 C 15.6 90.0 D 16.1 90.2

Test Example 3: Change in the maximum water absorption amount of the biopath according to the wetting treatment conditions

The maximum water uptake of each biopad sample was measured by cutting the biopad specimen to 2 cm x 2 cm size, immersing it in distilled water for 30 seconds, removing gravity water, and measuring the weight of the absorbed water. The maximum water uptake was shown by the ratio of the amount of water absorbed per weight of the specimen.

As shown in FIG. 6, as the concentration of the low-polarity solvent applied in the wet treatment increases, the absorption capacity of water increases and the maximum moisture absorption increases greatly as the pore and bulk of the bio-pads increase.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many obvious changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention should therefore be construed in light of the claims set forth to cover many of such variations.

100: pulp mold forming apparatus 110: upper mold
120: lower mold 130: ground liquid tank
140: Vacuum pump 200: Paper-making device
300: Roll 400: Solvent injection device
500: solvent recovery drying apparatus 600: water drying apparatus
700: process chamber

Claims (10)

A raw material dissolving step of mixing and dissolving raw fiber into water;
A wet paper fill forming and a vacuum dewatering step of forming the dissociated raw material fibers into a wet paper pellet form and vacuum dewatering the same;
A solvent wet processing step of spraying a mixed solvent in which a low-polarity solvent and water are mixed to the wet-dewatered vacuum-dehydrated filler, thereby replacing the moisture contained in the wet-matter filter with a low-polarity solvent;
A vacuum dewatering step of dewatering the moistened wet filter pellets in a vacuum state; And
And a drying step of drying the wet-dewatered wet paper pell at a constant temperature,
The solvent wet processing step and the vacuum dewatering step are performed in a process chamber in which the interior is kept in a reduced pressure state to minimize the outflow of the low polarity solvent,
The wet paper peeling and vacuum dewatering step may include pressing the dissociated raw material fiber with a pulp mold forming apparatus and sucking and dewatering with a vacuum pump to form a wet paper pellet,
In the pulp mold forming apparatus, the lower mold 120 is contained in the stock solution tank 130, and a certain amount of the stock solution is accommodated in the groove portion of the lower mold. The lower mold 120 is firstly contained in the stock solution by the vacuum pump 140 The upper mold 110 is lowered to be pressurized,
The solvent wet processing step may include a wet dewatering step of wet dewatering the wet dough formed through the wet dough forming step and the vacuum dewatering step, To 75% to 90% by weight,
The drying step may include: a primary drying step of drying the low-polarity solvent contained in the wet paper; And a second drying step of drying the wet paper to remove moisture remaining in the wet paper after passing through the primary drying step,
In the primary drying step, the low-polarity solvent contained in the wet paper is dried in a solvent recovery drying apparatus 500 maintained at a temperature of 80 ° C or lower, and the secondary drying step removes moisture remaining in the wet paper Lt; RTI ID = 0.0 > C, < / RTI >
Wherein the moisture drying apparatus includes a mesh belt or a porous mat having a mesh network in which a plurality of holes are formed, and a heat supply device for supplying heat.
The method according to claim 1,
Wherein the raw material fiber is made of any one selected from the group consisting of wood fiber, recycled woven fiber, wood fiber, cotton fiber, high purity cellulose fiber, herbaceous biomass fiber and natural fiber.
delete delete delete delete The method according to claim 1,
Wherein the low polarity solvent is any one selected from the group consisting of ethyl alcohol, acetone, ethyl acetate (EA), and isopropanol (IPA).
delete The method according to claim 1,
Wherein the air generated in the primary drying step is collected, condensed, and re-introduced into the solvent wet processing step.
delete

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