JP2002020966A - Method for squeezing sheet and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device, preventing the increase of liquid- containing rate at the both sheet end parts and enabling to obtain the sheet having an approximately homogeneous liquid-containing rate in its various positions in squeeze-treating the wet sheet with pressing roles. SOLUTION: This method for squeezing the sheet is characterized by injecting a gas to the both end parts of the sheet in contact with the roles for removing the liquid portion at the above both ends in squeezing the liquid from the wet sheet by using roles, and the device used for the above method is also provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for immersing a sheet made of a fabric such as a woven fabric, a nonwoven fabric, or a knitted fabric, or a sheet provided with a resin such as a polyurethane elastomer or polyvinyl chloride in a treatment liquid, When squeezing with a press roll after applying and moistening the treatment liquid in a shower form, it is possible to prevent an increase in the liquid content at both ends of the sheet and to uniformly control the liquid content of the entire sheet. The present invention relates to a method and an apparatus used therefor.

[0002]

2. Description of the Related Art Conventionally, a sheet is continuously used for various purposes such as applying a treatment liquid containing a resin, a softening agent, a lubricant, a surfactant, a dye, a pigment, etc. to a sheet, and solid-liquid extraction or washing. When processing, immersing the sheet in the processing liquid,
2. Description of the Related Art A method is widely used in which a treatment liquid is applied to a sheet in the form of a shower to wet the sheet, and then the treatment liquid is squeezed by a press roll. However, the wet sheet obtained by this method has a serious problem that the liquid content at both ends is higher than that at the center since the treatment liquid is reabsorbed from both ends immediately after pressing. If the liquid content at both ends of the sheet is higher than the central part of the sheet, such a sheet has different adhesion rates of resin, softener, lubricant, surfactant, dye and pigment at both ends and the central part of the sheet. In the case where there is a difference in physical properties between both ends and the center of the sheet, or when raising the sheet surface in a later process,
At the time of raising, the length of the bristle feet is different at both ends and the center,
There have been problems such as the occurrence of spots on the external surface such as a hue difference during dyeing.

[0003] As a countermeasure against such a problem, a method of removing the liquid at both ends of the sheet by using a press roll having a larger diameter at both ends than at the center, or applying a treatment liquid only to the center of the sheet and pressing the sheet. The method of squeezing and squeezing is conceivable, but it has problems such as not being able to cope with sheets of various forms, increasing the cost, or obtaining a uniform liquid content, making it difficult to obtain satisfactory quality. And none of them are satisfactory.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to prevent the liquid content at both ends of the sheet from increasing when the wet sheet is squeezed by a press roll, so that the liquid content at each part is substantially reduced. It is an object of the present invention to provide a method which makes it possible to obtain a sheet which is uniform and a device which can do so.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above problems, and as a result, when squeezing a wet sheet using a roll, the roll and the wet sheet come into contact with each other. That is, the present invention is achieved by removing the liquid component at both ends of the sheet by jetting gas to both ends of the sheet or both ends of the sheet before and after the sheet, and squeezing the wet sheet using a roll. In a liquid squeezing device for liquid, a wetting characterized by having a gas injection port capable of injecting gas to both end surfaces of a sheet at a position where a roll and a wet sheet are in contact or to both end surfaces of a sheet before and after the same. It has been found that the present invention is achieved by a sheet squeezing device.

The reason why the liquid content at both ends and the center of the wet sheet is made substantially uniform by the present invention is not obvious.
A remarkable effect is exhibited by the method of the present invention, and the gas blows off the free liquid on the roll surface to suppress re-absorption of the processing liquid, and includes a function of appropriately blowing off the processing liquid absorbed in the sheet. It is assumed that the liquid ratio can be made uniform.

In the liquid squeezing device of the present invention, a press roll and a nozzle for injecting gas to both ends of the sheet in contact with, before or after the roll are provided.

[0008] The material of the press roll used in the present invention includes metal, rubber, plastic and the like, and may be a composite thereof. The shape may be such that the roll surface is smooth or uneven. Further, the roll diameter may be different between the center and the end in the width direction. Further, the pressing pressure is not particularly limited, and any pressure can be used as long as it has a squeezing effect. The cloth path through which the press roll passes can be any of various types such as an S-shape, a U-shape, an L-shape, and an I-shape, but is not particularly limited.
FIGS. 1 to 4 show a cloth path passing through a press roll. FIG. 1 shows an S shape, FIG. 2 shows a U shape, FIG. 3 shows an L shape, and FIG. 4 shows an I shape. Can be used.

FIG. 5 is a perspective view schematically showing an embodiment of the present invention. FIG. 6 is a side view of the device shown in FIG. Further, FIG. 7 shows a top view of the apparatus shown in FIG. In these figures, 1 and 2 indicate gas injection nozzles, 3 indicates a press roll, 4 indicates a wet sheet, and 5 indicates the injected gas.

[0010] Examples of the gas jetted to both ends of the sheet used in the method of the present invention include air, nitrogen, oxygen, hydrogen, water vapor, and inert gas. Among them, from the viewpoints of handleability and economy. Air is preferred. The temperature of the gas is usually in the range of −50 ° C. to 200 ° C., and particularly, 0 to 50 ° C. in terms of handleability and economy.
Is preferable.

The position at which the gas is injected to the sheet is not particularly limited as long as it is at or before or after the portion where the roll and the sheet are in contact with each other. And the part where the sheet is in contact, more preferably a method of directly ejecting the part after the press part and the part where the roll and the sheet are in contact, most preferably directly ejecting to the press part and from the press part This is a method in which the gas is jetted directly to the rear portion where the roll and the sheet are in contact, that is, a method in which gas is jetted to the above-mentioned portion in two or more stages.

In the present invention, it is necessary to inject gas to both ends of the sheet, and if only one end is provided, it is not possible to obtain a uniform application amount in the entire width direction of the sheet. Further, in the present invention, the width of the sheet is 0.1 mm from both ends of the sheet.
It is preferable that the gas is injected so that the gas hits from the inner portion of 5% or more to both ends. More preferably, it is a case where the gas is sprayed so as to impinge on the portion from 1.0% or more inside both ends of the sheet to both ends with respect to the width of the sheet. If it is less than 0.5%, the liquid removing effect is low and the liquid content may not be uniform. The gas may be injected so as to impinge on the center of the sheet, but it is not preferable from the economical point of view because the injection area becomes large and the air volume increases to obtain a desired wind speed.

The distance between the sheet and the gas injection nozzle (the distance between the gas injection nozzle and the surface of the sheet from which the gas is injected) is preferably 200 mm or less, and more preferably in the range of 20 mm to 100 mm. 200mm
If it is larger, the spray gas may diffuse and the liquid removing effect may be reduced. The angle between the gas injection direction and the circumferential surface of the press roll is not particularly limited as long as it has a liquid removing effect. In addition, there is no particular limitation as long as there is a liquid removing effect even at an angle between the gas ejection direction and the sheet traveling direction, but the free liquid on the roll surface is blown off to suppress the re-absorption of the processing liquid or to absorb the treatment liquid into the sheet. In order to increase the liquid removing effect by appropriately blowing off the processing liquid, it is preferable to inject the jet gas so as to be in a direction of 0 to 60 °, particularly 5 to 30 ° outward from the parallel direction of the sheet. .

The shape of the injection nozzle is not particularly limited as long as it satisfies the above-mentioned injection conditions. However, a slit-shaped injection hole is preferable in order to efficiently obtain a suitable wind speed. 1-5mm, slit length 1-20cm, slit length / slit width 5-5
00, and the slit-shaped injection holes are preferably provided so that the length direction of the slit is substantially parallel to the sheet surface.

The wind speed of the jet gas depends on the processing speed, the viscosity of the processing solution, the desired liquid content, and the like, but it should be in the range of 2 to 500 m / sec, particularly 20 to 200 m, at the sheet surface portion to which the jet gas is applied. / Sec is preferred. Wind speed 2m /
If it is less than seconds, the removing effect is not sufficient, and if it is more than 500 m / s, the processing solution may be excessively removed.

The sheet of the present invention is a woven fabric obtained from synthetic fibers such as polyamide, polyester and polyacrylonitrile, artificial fibers such as rayon, cupra and acetate, and natural fibers such as silk, cotton, wool and hemp. , A knitted cloth, a raised cloth, a non-woven cloth, or a cloth obtained by adding a resin such as a polyurethane elastomer or polyvinyl chloride to the cloth.

The thickness of the sheet is selected from the range of 0.3 to 10 mm, and the width of the sheet is selected from the range of 30 cm to 300 cm according to the specifications of the product. The apparent specific gravity of the sheet is preferably in the range of 0.1 to 0.8 g / cm ³ . If the apparent specific gravity is lower than 0.1 g / cm ³ , the strength of the sheet may be reduced and the processability may be reduced. On the other hand, when the apparent specific gravity is higher than 0.8 g / cm ^{3, the} liquid content in wet condition is low and the liquid removing effect may be reduced.

The speed at which the sheet passes through the press roll is as follows:
The range of 1 m / min to 100 m / min is preferable in view of the squeezing effect and the process passability. The pressure of the press roll is preferably in the range of 0.1 kg / cm to 10 kg / cm in linear pressure. The sheet liquid content before wetting after wetting of the treatment liquid is 3 by weight.
A range of 0 to 300%, particularly a range of 50 to 200% is preferred. If it is lower than 30%, the liquid removing effect will be low,
If it is higher, the processability may decrease.

The type of the treatment liquid used in the present invention includes water or an organic solvent alone, a resin solution or an emulsion, a dispersion or solution of an oil agent, a dye, a pigment, or the like. The viscosity of the treatment liquid is preferably in the range of 1.0 Pascal second or less. When the viscosity is higher than 1.0 Pascal-second, the viscosity is too high, and the liquid removing effect by the jet gas may be remarkably reduced.

Sheets processed by the apparatus of the present invention are:
By selecting appropriate conditions for the wind speed within the above range, it has a substantially uniform liquid content in the width direction, and the physical properties at both ends and the center, uniform without any difference in appearance. You can get a sheet.

[0021]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples.

[Tear Strength] JIS L1096
6.15.1 Measured by A-1 single tongue method.

[Liquid Content] (Wet sheet-containing treatment liquid weight / dry sheet weight) × 10
0%

[Adhesion rate of softener] (Solid weight of softener / weight of dry sheet) × 100%

Example 1 A sheet was squeezed using the apparatus shown in FIG. FIG. 3 is a view showing an embodiment of the present invention, in which a sheet is passed through a metal press roll 3 for squeezing liquid in an S-shape in the direction of →. The sheet subjected to the continuous squeezing treatment with a press line load of 0.5 kg / cm at that time has a width of 150 cm.
Air at 20 ° C. is directly jetted from the rear side of the press roll to both ends of the sheet at the press site. The injection nozzle at that time is 1 shown in FIG. 5, and nozzles 2 for injecting the same air are provided at both ends of the sheet wound around the rear side of the press roll. The air velocity and the flow rate of the air jetted from 1 and 2 are adjusted by a valve or the like. The slit shape of each nozzle is 100 mm in length and 2 mm in width.
The sheet is set so as to hit the inside position, so as to be 10 ° outward from the direction parallel to the traveling direction of the sheet, and so as to have a distance of 70 mm from the sheet.

Using such an apparatus, an average single fineness of 0.1 is used.
Squeezing of a 1.5 mm thick, 150 cm wide, apparent specific gravity 0.3 g / cm ³ sheet in which a three-dimensional entangled non-woven fabric made of a 004 decitex nylon ultrafine fiber bundle contains a dyeable polyurethane in a porous state. went. That is,
The sheet was immersed in a 1% aqueous dispersion of an amide-based softener and having a viscosity of 0.001 pascal-second, and the sheet having a liquid content of 200% was subjected to the above-mentioned apparatus. Squeezing treatment was performed. At this time, the air velocity of the air jetted from the nozzles 1 and 2 was 40 m / sec, and the speed of the sheet passing through the roll was 10 m / min.

The liquid content of the sheet obtained by this apparatus was 110% at the center and 110% at both ends, and the adhering rate of the softener was 1.1% each. The sheet obtained by drying the sheet had a tear strength of 7.0 kg at the center and 7.2 kg at both ends. The sheet obtained by buffing the surface of the sheet had a uniform fluff length of about 0.06 mm at both the center and both ends. Further, when this was dyed with a gold-containing dye, the dye adherence rate was uniform since the softener adhesion rate was uniform, and the dye had an excellent appearance with no color difference in the width direction.

Examples 2 to 4 and Comparative Example 1 The sheet was subjected to a squeezing treatment in exactly the same manner as in Example 1 except that the conditions of the air jetted from the nozzles 1 and 2 were changed as shown in Table 1. The sheets obtained by the processing methods of Examples 2 to 4 had a small difference in the liquid content, the softener adhesion rate, and the tear strength between the central portion and both end portions, and were sufficiently practical for practical use.
The sheet obtained by the processing method of Comparative Example 1 had a liquid content of
There was a large difference between the center and both ends in both the softener adhesion rate and the tear strength, and there was also a difference in the average fluff length at the time of raising and the color difference after dyeing, so that it was not practical in quality.

[0029]

[Table 1]

[0030]

The wet sheet squeezed by the apparatus and method of the present invention has a uniform adhesion rate, extraction and washing ratio of resins, softeners, lubricants, surfactants, dyes and pigments at each site. Therefore, there is no problem such as a difference in physical properties between the both ends and the central part, or an abnormality in appearance in a later step such as raising or dyeing, and it is possible to efficiently obtain a sheet of excellent quality. it can.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a case where a cloth path is S-shaped.

FIG. 2 is a diagram schematically illustrating a case where a cloth path is U-shaped.

FIG. 3 is a diagram schematically showing a case where a cloth path is L-shaped.

FIG. 4 is a diagram schematically illustrating a case where the cloth path is an I-shaped.

FIG. 5 is a perspective view schematically showing an embodiment of the present invention.

FIG. 6 is a side view of the apparatus shown in FIG.

FIG. 7 is a top view of the apparatus shown in FIG.

[Explanation of symbols]

 1: nozzle 1 2: nozzle 2 3: press roll 4: sheet 5: blast air

Claims (3)

[Claims] When squeezing a wet sheet using a roll, a gas is sprayed onto both end surfaces of the sheet where the roll is in contact with the wet sheet or on both end surfaces of the sheet before and after the squeezed sheet. A liquid squeezing method for a sheet, comprising removing at least a part of a liquid part of a sheet. 2. The air velocity of the gas in contact with both ends of the sheet is 2 to 5
The method according to claim 1, wherein the pressure is in the range of 00 m / sec. 3. A liquid squeezing device for squeezing a wet sheet using a roll, wherein gas can be jetted to both end surfaces of the sheet at a position where the roll and the wet sheet are in contact, or to both end surfaces of the sheet before and after the wet sheet. A sheet squeezing device having a gas injection port.