JPS6151066B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for removing soluble components from fibrous sheets. More specifically, the fibrous sheet is brought into contact with the surface of a rotating drum that is suspended in a solvent, and the solvent is absorbed into the rotating drum through the fibrous sheet, thereby dissolving and removing the soluble components contained within the fibrous sheet. It relates to a device for.

Traditionally, a woven fabric is brought into contact with the surface of a rotating drum suspended in a solvent, and the solvent is absorbed into the rotating drum through the woven fabric, thereby dissolving and removing the glue, dye, etc. contained in the woven fabric. Methods are known. For example, Japanese Patent Publication No. 30-8539 proposes an apparatus using the above-mentioned principle as an apparatus for washing or dyeing woven fabric. However, although such a device can be used for fibrous sheets with extremely good liquid permeability, such as woven fabrics, it cannot be used for fibrous sheets with poor liquid permeability, that is, thick fibrous sheets with dense internal structures. had the disadvantage that it could not be used. This is because when a fibrous sheet with poor liquid permeability is processed using a rotating drum method, the solvent enters only from areas where it does not receive resistance, that is, from the surface of the drum that is not covered by the fibrous sheet, and the solvent flows inside the fibrous sheet. Almost no fluid passes through it,
This is because the soluble components within the fibrous sheet are hardly subjected to the action of dissolution and removal.

In recent years, fabrics such as nonwoven fabrics, woven fabrics, and knitted fabrics to which polyurethane elastomer is applied in a porous manner have been used as substrates for artificial leather. As a method for producing these artificial leather substrates, generally soluble polymeric substances such as polystyrene and polyethylene and insoluble polymeric substances such as polyethylene terephthalate and polyamide are mixed-spun or composite-spun, and fabrics are made from the resulting multicomponent mixed fibers. A method is to compose the artificial leather, impregnate it with a solution or dispersion of polyurethane elastomer, coagulate it into a porous state, and extract and remove the soluble polymer substance in order to impart flexibility and breathability to the resulting artificial leather substrate. It is used. In addition, when constructing the fabric, in order to maintain the shape of the fabric or to make the resulting artificial leather base supple, the fabric is temporarily fixed with a soluble polymeric substance such as polyvinyl alcohol or starch, and then polyurethane is added to the fabric. A method of dissolving and removing soluble polymer substances during or after coagulating the elastomer is also commonly used. Substrates for artificial leather usually have a large thickness and a dense internal structure, so that soluble polymer substances are difficult to dissolve and remove.

Conventionally, as a method for dissolving and removing soluble polymer substances from an artificial leather substrate, as described in Japanese Patent Publication No. 48-41788, the artificial leather substrate is immersed in a solvent. A method has been adopted in which the process of squeezing out the liquid and immersing the substrate in the solvent is repeated many times. Using this method, it is true that the soluble polymer substance can be almost completely dissolved and removed, but on the other hand, the artificial leather substrate has to pass between multiple stages of nip rolls, and is subjected to excessive tension between the rolls. This results in distortion. Furthermore, since multiple stages of nipprols and solvent tanks are required, the process becomes longer and a large number of personnel are required to manage the process.

As a device for dissolving and removing soluble components from fibrous sheets with extremely poor liquid permeability, such as artificial leather substrates, it is possible to use a rotating drum instead of the commonly used multi-stage nip roll, and the dissolution and removal efficiency is high. If the tension is sufficiently high, excessive tension will not be applied to the fibrous sheet and the process can be extremely shortened, making it extremely useful.

An object of the present invention is to provide a rotating drum type dissolving and removing treatment apparatus suitable for treating fibrous sheets with poor liquid permeability. That is, in the present invention, a rotating drum is mounted on a shaft in a tank filled with a solvent, the rotating drum is rotated with the fibrous sheet in contact with the circumferential surface of the rotating drum, and liquid is absorbed through the fibrous sheet into the drum. In an apparatus for dissolving and removing soluble components from a fibrous sheet, the circumferential surface of the rotating drum is covered with a net-like material or a porous material (hereinafter both are collectively referred to as a "net-like material"), and this net-like material Below is a plate with a liquid suction port (hereinafter abbreviated as liquid suction port plate), and between this liquid suction port plate and a net-like material is a plate for dividing the surface of the liquid suction port into a plurality of small sections. This device is characterized by the presence of a partition plate.

Next, a specific example of the apparatus of the present invention will be explained with reference to the accompanying drawings. FIG. 1 is a longitudinal sectional view of the entire processing apparatus. In the figure, processing tank 1 filled with solvent 2
A rotary drum 4 is rotatably mounted in the liquid. The fibrous sheet 3 is a guide roll 5
The liquid is guided into the liquid, passes through the guide roll 6 and comes into contact with the circumferential surface of the rotating drum, and in this state, the rotating drum 4
is gradually fed as the guide roll 7 rotates.
It exits the tank through steps 8 and 8. While the fibrous sheet 3 is in contact with the circumferential surface of the rotating drum 4, the soluble components are dissolved and removed, and at least a portion of the circumferential surface of the rotating drum absorbs the solvent into the drum through the fibrous sheet. It has a structure that allows it to be dissolved and removed. In the case of FIG. 1, the upper half of the rotating drum 4 has a structure capable of absorbing liquid, and the solvent sucked into the rotating drum is taken out from inside the rotating drum through a pipe 9 by a pump 10, and sent from a pipe 11 to a processing tank. It is returned to 1. Further, the lower part of the rotating drum 4 is structured to allow backwashing. In other words, the liquid 2 inside the processing tank 1
is pressurized by the pump 13, and foreign substances such as dust, fiber waste, and polymer waste are removed by the strainer 14, and then the pipe 1 is
The foreign matter attached to the surface of the rotating drum 4 is dispersed by press-fitting the liquid into the rotating drum through the rotary drum 5 and releasing the press-fit liquid from the lower part of the rotating drum 4 to the outside of the drum.

FIG. 2 is a diagram showing the structure of the rotating drum 4. As shown in FIG.
The rotating drum 4 has shaft ends 16 and 17 supported by bearings provided outside or inside the tank, and is rotationally driven. A large number of liquid suction ports 21 are provided on the surface of the rotating drum 4 so that the solvent can enter the drum from outside. However, in the case of a fibrous sheet with poor liquid permeability, the solvent may enter the drum exclusively from areas not covered by the fibrous sheet, or the solvent may flow unevenly within the fibrous sheet, causing soluble components to The removal process tends to be incomplete, but in order to prevent this, in the present invention, the surface of the drum has a cross section as shown in FIG. That is, the outermost peripheral surface of the rotating drum in contact with the fibrous sheet is covered with a net-like material 18, and below it is a plate 20 having a liquid suction port (hereinafter referred to as liquid suction port plate) and the surface of this liquid suction port plate. There is a partition plate 19 for dividing the liquid into a plurality of small sections, and each section divided by the partition plate 19 is provided with at least one liquid suction port 21 communicating with the inside of the rotating drum. Particularly, the part where both ends of the fibrous sheet touch is the partition plate 1.
Since the fibrous sheet partially covers the compartment divided by 9, the liquid does not flow through the sheet and passes exclusively through the areas not covered by the fibrous sheet, resulting in insufficient dissolution and removal treatment. However, by sufficiently narrowing the distance between the partition plates (in the drum axis direction) at this location, it is possible to reduce the proportion of unprocessed portions. In addition, by sufficiently reducing the diameter of the liquid suction ports 21 provided in each section separated by the partition plate 19 to increase liquid resistance, the amount of liquid that enters from areas not covered with the fibrous sheet can be relatively reduced. can be reduced. Furthermore, the compartments partitioned by the partition plate 19 are completely separated by the mesh 18, the partition plate 19, and the liquid suction port plate 20, and the liquid that permeates into the compartment is removed from the fibrous sheet in contact with the partition. Preferably, the flow of liquid between the compartments through the mesh 18 is almost negligible, such that only liquid enters through the partition plate 1.
It is preferable that the partition plate and the partition plate be integrated on the top of the partition plate 9 without any gaps. In this respect, it is most preferable to use a punched wire mesh with an appropriately selected hole diameter and pitch as the mesh material. Note that punched wire mesh is a thin metal plate with regularly arranged round or square holes with a porosity of 10 to 50.
% perforated plate. In addition to the above-mentioned punched wire mesh, the net-like material referred to in the present invention may include, depending on the purpose of processing,
It is a general term for materials used such as cloth, felt, metal or plastic mesh, and sintered metal.

In addition, if the liquid suction port 21 is blocked by fiber waste, polymer waste, etc., the fibrous sheet that is in contact with the section leading to the liquid suction port will not be subjected to the dissolution and removal process, and will be extracted into the fibrous sheet. There will be spots that have not been treated, but in order to prevent this from occurring, it is possible to prevent this by making the mesh diameter of the mesh provided on the surface of the rotating drum smaller than the diameter of the liquid suction port. It is valid as

The size of the rotating drum constituting the device of the present invention, the mesh diameter of the net-like material 18, the diameter of the liquid suction port 21,
The size of the compartments divided by the partition plate 19 varies depending on the processing speed, the required amount of liquid to be passed, the liquid permeability of the fibrous sheet to be processed, and the like. Generally, the diameter of the rotating drum is
30 to 100 cm is an appropriate range from a production standpoint. When a punched wire mesh is used, the mesh diameter of the mesh material 18 is as follows:
0.5 to 1.5 mm, porosity is 10 to 30%, the diameter of the liquid suction port 21 is 2 to 4 mm, the size of one section divided by the partition plate 19 is 2 to 8 cm in length in the drum axis direction, and the area 20 in
~ ^80cm2 is preferred.

Regarding the liquid permeability of the processed fibrous sheet,
It is represented by the following formula (1).

ΔP=Rμ/gcυ...(1) Here, ΔP is the resistance of the fibrous sheet during liquid passage (Kg/m ² ), and R is the resistance coefficient of the fibrous sheet (1/m 2 ).
m), μ represents the viscosity of the solvent (Kg/m·sec), gc represents the gravity coefficient (9.8 m/sec ² ), and υ represents the average flow rate of the solvent (m/sec). And in the present invention,
The resistance coefficient R is preferably 10×10 ⁹ 1/m or less, but 50
It is possible to process even a surface of about ×10 ⁹ 1/m.

FIG. 4 is a longitudinal cross-sectional view of part A of the rotating drum 4 shown in FIG. One end of the inside of the drum is sealed, and the other end surface is a smooth surface with holes 23 in each section formed by a partition plate 22, as shown in FIG. A fixing box 24 having a smooth surface with holes 25 and 26 shown in FIG. 6 is pressed against this surface by a spring 29. The inside of the fixed box 24 is divided into two parts by a partition plate 30, and the liquid that has entered the fixed box 24 through each hole 25 is discharged from the pipe 27, and the liquid that has entered the fixed box 24 from the pipe 28 is discharged through the hole 26. These liquids are press-fitted into the rotating drum from the fixed box 2.
4 has a structure in which they do not mix.

The apparatus of the present invention has the structure as described in detail above, but to explain the flow of the solvent again, it is sucked through the pipe 27 by the pump 10 outside the tank, so that the inside of the processing tank 1 is The solvent passes through the fibrous sheet 3 and enters the inside of the drum from the mesh 18 through the liquid suction port 21 provided in the liquid suction port plate 20, and enters the inside of the drum through the hole 23 which coincides with the hole 25 of the fixed box 24.
The liquid inside the roll leading to passes through holes 23 and 25,
It will be discharged from the tank through the pipe 27. On the other hand, the solvent pressurized by the pump 13 outside the tank is transferred to the pipe 2
8, enters the fixed box 24, enters the rotating drum through the hole 23 of the rotating drum that matches the hole 26,
The liquid is discharged to the outside of the rotating drum from the liquid suction port of the liquid suction port plate in that section. At this time, dust, fiber debris, etc. adhering to the net-like material on the surface of the rotating drum are dispersed from the drum surface, and so-called backwashing is performed. Further, as the rotary drum rotates relative to the holes 25 and 26 of the fixed box 24, the holes 23 provided in the rotary drum receive alternate flows of suction and backwashing liquid. In order to increase the dissolution and removal processing section of the fibrous sheet, it is sufficient to increase the angle (α in FIG. 6) of the hole 25 of the fixed box 24.
Further, in order to perform sufficient backwashing, the angle of the hole 26 (β in FIG. 6) may be made large.

In the apparatus of the present invention, the liquid permeability of the fibrous sheet is extremely poor, and it is difficult to draw the solvent from outside the rotating drum into the rotating drum through the fibrous sheet.
When a suction force close to Kg/cm is required, or when the solvent is heated to a temperature close to its boiling point, a rotating drum may be installed at the bottom of the tank to increase the liquid depth, or It is preferable to adopt a method of pressurizing the liquid to force the liquid.

There is also a method in which the solvent is discharged from the inside of the rotating drum to the outside, contrary to the method described above. Although a device for pressing the fibrous sheet onto the circumferential surface of the drum is added, the structure of the drum is basically the same.

As detailed above, by using the device of the present invention, soluble substances can be sufficiently dissolved and removed even from fibrous sheets with poor liquid permeability, and in addition, excessive tension is applied to the fibrous sheets compared to conventional multi-stage nip rolls. The present invention has extremely great advantages, since it does not require much time and the steps can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a front view of the entire device of the present invention, and FIG. 2 is a diagram of the rotating drum, which is the main part,
Figure 3 is a vertical sectional view of the surface of the rotating drum, numbers 4 to 6.
The figure is a cross-sectional view of the rotating drum shown in FIG. 2 taken at sections A, B, and C, respectively.

Claims (1)

[Claims] 1. A rotary drum mounted on a shaft in a tank filled with a solvent,
In an apparatus for dissolving and removing soluble components from a fibrous sheet by rotating the rotating drum while keeping the fibrous sheet in contact with the circumferential surface of the rotating drum and absorbing liquid through the fibrous sheet into the drum. A plate whose peripheral surface is covered with a net-like material or a porous material, and below the net-like material or porous material has a liquid suction port (hereinafter abbreviated as liquid suction port plate), and this liquid suction port plate. Between the mesh or porous materials there is a partition plate for dividing the surface of the liquid suction port plate into a plurality of small sections, and the small sections are further divided into one block in the width direction of the rotating drum. A plate is provided inside the rotating drum to form a plurality of blocks inside the rotating drum, and each block has a hole in the side surface of the rotating drum, making surface contact with the hole communicating with the drain pipe and the liquid supply pipe provided in the fixed box. An apparatus for removing soluble components from a fibrous sheet, characterized in that a pump for discharging liquid from a rotating drum and a pump for supplying liquid into the rotating drum are connected. 2 Claim 1 in which the mesh is a punched wire mesh
Apparatus described in section. 3. The device according to claim 1 or 2, wherein the pore diameter of the net-like material or porous material is smaller than the pore diameter of the liquid suction port.