JPH08226060A - Production of fiber layer material - Google Patents

Abstract

PURPOSE: To provide a method for producing a fibrous layer material suitable as a mat, a filter medium, comprising fibers arranged in the thickness direction, having rigidity and hardly loosening. CONSTITUTION: A fiber web comprising thermally bondable fibers 2 arranged in one direction is formed. The fiber web is heated to a temperature equal to or higher than the melt point of the thermally bondable fibers 2 so that the fibers constituting the fiber web are mutually and partially bonded 3 to form a fiber sheet 5. Then the fiber sheet 5 is folded in the vertical direction based on the direction of the fiber arrangement. Then the folded material is compressed approximately at a right angle to the folding direction, reheated to a temperature equal to or higher than the melt point of the thermally bondable fibers 2, mutually and partially bonded and integrated to give a fiber lump. Then the fiber lump is cut approximately in the vertical direction based on the fiber arrangement direction to produce the objective fiber layer material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fibrous layer material which has a low density, a high shape-retaining property, a low settling property, a high rigidity, a high cushioning property, a high air permeability, and is hard to come loose.

[0002]

2. Description of the Related Art Fiber layer materials have hitherto been used in various applications as mat materials or filter materials. In the conventional fiber layer material, as shown in FIG. 4, the fibers 2 constituting the fiber layer material and bonded to each other 3 are substantially parallel to the surface of the fiber layer material, that is, substantially in the thickness direction of the fiber layer material. They are arranged at right angles. Therefore, in the case of a fiber layer material having a small density of 0.1 g / cm ³ or less, it has a defect that it is easily deformed by a load from the thickness direction, has poor shape retention, and has a large settling. To prevent these deformations, eliminate settling, or improve cushioning properties, the density of the fiber layer material should be 0.1 g.
It was necessary to make the density as high as / cm ³ or more. Further, the fiber layer material is often used as a filter for various air conditioning, but when a conventional fiber layer material in which fibers are arranged in a direction substantially perpendicular to the thickness direction of the fiber layer is used for the filter, Due to the pressure loss due to the flow of air, the filter material is compressed, the pressure loss rises quickly, and a large amount of dust cannot be retained. The present invention solves the drawbacks of the conventional fiber layer material as described above, and has a density of 0.1 g /
Even when it is as small as cm ³ or less, it has excellent shape retention, small deformability with respect to the load in the thickness direction, little settling, strong elasticity and resilience, rich cushioning property, and good breathability and mats and filters. An object of the present invention is to provide a method for producing a fiber layer material suitable for the material.

Further, a card-spun web containing a non-binder fiber composed mainly of synthetic fibers and a binder fiber is folded in a cross layer to be laminated substantially horizontally, and the laminate is compressed in the laminating direction of the web. While heat-treating at a temperature not lower than the melting point of the binder fiber and not higher than the melting point of the non-binder fiber, the binder fiber is melted and the constituent fibers are adhered to each other to form the web, and the web is molded and fixed. Also, a fiber structure for plant cultivation in which the orientation of the fibers is oriented in a specific direction is known (JP-A-1-118656). It is an object of the present invention to provide a manufacturing method for efficiently producing a fiber layer material suitable for a mat or a filter material, in which the rigidity of such a fiber structure is improved and dispersion of constituent fibers is improved.

[0004]

Means for Solving the Problems That is, the present invention forms a fiber web containing heat-adhesive fibers and having fibers arranged in one direction. By heating, the fibers constituting the fiber web are partially adhered to each other to form a fiber sheet, and then the fiber sheet is folded in a direction perpendicular to the fiber arrangement direction, and then this folded product is compressed in a direction substantially perpendicular to the folding direction. Then, by heating again to a temperature higher than the melting point of the heat-adhesive fiber to partially bond the fibers to each other to form an integrated fiber mass, and then cutting the fiber mass in a direction substantially perpendicular to the fiber arrangement direction. And a method for producing a fiber layer material.

The method for producing the fiber layer material of the present invention will be described in detail. The heat-adhesive fiber used in the present invention is a fiber that is melted by heating and exhibits adhesiveness, and has a function of adhering fibers to each other when heated. Although it depends on the condition at the time of heat bonding or the texture of the finished product, it is necessary to mix at least 10% or more of the entire fiber. When it is less than 10%, when cut into a fibrous layer material, it is more distorted than the non-bonded portion, and the shape retention is deteriorated. As the heat-adhesive fiber, any synthetic fiber may be used as long as it is a synthetic fiber that melts at a temperature lower than that of the main fiber constituting the fiber layer material, but it is preferable to use, for example, polyester or polypropylene as a core and low melting point polyester or polyethylene as a sheath. These are core-sheath type or side-by-side type composite fibers thereof. Further, a fiber having a low melting point resin adhered or coated thereon can also be used. When these composite fibers are used as the heat-adhesive fibers, the fiber web may be composed of only the heat-adhesive fibers. The rigidity of the fiber layer material can be appropriately changed depending on the mixing amount of the heat-adhesive fibers and the heat treatment condition, and the rigidity of the fiber layer material increases as the ratio of adhesion between the fibers increases. Further, heat-meltable synthetic resin particles may be used for adhering the fibers to each other.

The fibers used in the present invention mixed with the heat-adhesive fibers are polyester fibers, polypropylene fibers, acrylic fibers, rayon, acetate fibers, glass fibers, carbon fibers, various natural fibers, etc., alone or in combination. Is a fiber having a higher melting point than the heat-adhesive fiber. These fibers may be used alone or in combination of two or more. Further, crimped fibers that are crimped by heating can also be used. The thickness of the fiber can be appropriately determined according to the application and is not particularly limited. For example, when it is used as a seat mat material for automobiles, a thick fiber having a denier of 15 denier or more, which is easy to secure the rigidity of the fiber, is preferable, and an extremely fine fiber having a denier of about 1 denier is used as a filter material in order to particularly improve collection efficiency.

Various methods can be used to manufacture a fiber web in which fibers are arranged in one direction. For example, a fibrous web obtained by aligning long fibers in one direction or a fibrous web obtained by carding short fibers and arranging them in one direction is superposed in a desired thickness so that the fiber arrangement directions are the same direction. To manufacture. When all the fibers constituting the web are completely oriented in one direction when forming the above-mentioned fiber web, the fiber layer material of the final product obtained is such that the fibers are completely oriented in the thickness direction. The orientation of the fibers of the fiber layer material of the present invention does not require that all the fibers be oriented in the thickness direction, but in order to utilize the inherent elasticity of the fibers and improve the air permeability, the total fibers It is necessary that 50% or more of them be arranged in the thickness direction. Therefore, it is necessary to arrange 50% or more of all the fibers in one direction in the fiber web as the raw material. In order to check the fiber orientation of this fiber web, the fibers in a fixed field of view may be observed with a microscope, the number of fibers arranged in one direction may be counted, and the ratio may be calculated. A method of measuring the lateral strength and calculating the ratio thereof to check the orientation of the fibers may be used. For example, the longitudinal and transverse strengths of the fiber web are 30 Kgf / 5 cmW and 15 Kgf / 5c, respectively.
If it is mW, the longitudinal orientation of the fibers of the fiber web is 30 / (30 + 15) = 66.7%. And this orientation also becomes the orientation of the fibers in the thickness direction of the fiber layer material of the present invention. Also, the basis weight of the fiber webs, when operating to perform a folded below the corrugated, so as to be a uniform 150 g / m ² or less, preferably from 30 to 80 g / m ^2.

In the present invention, the above-mentioned fiber web in which the fibers are arranged in one direction is heat-treated at a temperature not lower than the melting point of the heat-adhesive fiber and not higher than the melting point of the other fiber, and included in the fiber web. The heat-bondable fibers are melted and the fibers of the fiber web are bonded together to form a fiber sheet. A fiber web in which fibers are not bonded to each other while the fibers are arranged in one direction can also be used as a material for the fold operation described below.
When using this unbonded fiber web as the material,
A fiber layer material having a soft feel is obtained. On the other hand, as in the present invention, when a fiber sheet in which the fibers of the fiber web are partially bonded to each other is used as a material, a fiber layer having a rigid feel is obtained, and in this case, many bonded parts of the fibers are present. As a result, a fiber layer in which the fibers are less scattered can be obtained.
That is, by using as a raw material the fibers of a fibrous web adhered to each other, compared to the case where the above-mentioned fibrous web in which the fibers are not adhered to each other is used as a raw material, even if the same fiber is used as a raw material, It is possible to obtain a fibrous layer material having a good feel, and to obtain a strong fibrous layer material in which the number of bonded portions between the fibers is increased and the fibers are less scattered.

Further, when the above-mentioned fiber web in which the fibers are arranged in one direction is used as it is, since it is too bulky and the number of folds cannot be increased during the folding step which will be described later, the crimping force at the time of compression heating becomes weak and the finish Further, the fibers of the lump of fibers cannot be sufficiently adhered to each other, and the fiber layer material is likely to come apart.
The above-mentioned fibrous web is heated, and the fibrous sheet in which the fibers are heat-bonded to each other with the heat-adhesive fibers is relatively dense because the fibers are bonded to each other, and thus the number of folds is large and the fibers can be smoothly moved. It is possible to obtain a fiber layer material that can be compressed and heated, has good production efficiency, and is resistant to variation. Therefore, in the present invention, a fiber web in which fibers are arranged in one direction is once subjected to heat treatment, and the heat-adhesive fibers contained in the fiber web are heated and melted to form a fiber sheet in which the fibers are adhered to each other, and the following folding is performed. Shift to process.

In the present invention, the fiber sheet obtained as described above is folded in a direction perpendicular to the fiber arrangement direction, and then this folded product is compressed in a direction substantially perpendicular to the folding direction, and the melting point of the heat-adhesive fiber is again obtained. The heating is performed at a temperature below the melting point of the other fibers. By this compression heating, a fiber mass in which the fibers are partially adhered and integrated is obtained. Specifically, this operation is performed by sequentially folding a long fiber sheet having a constant width into a fold shape in a direction perpendicular to the fiber arrangement direction and compressing it in a direction substantially perpendicular to the folding direction to obtain a predetermined density. It is preferable to adopt a method in which hot air is blown through and the heat-adhesive synthetic fibers or heat-meltable synthetic resin particles in the web mixed in advance are melted to bond the fibers to each other and integrate them. According to this method, The web laminate can be manufactured continuously. Further, when the fiber sheet is fold-folded, if a small amount of the heat-fusible resin is adhered to the surface of the fiber sheet, the adhesion between the fiber sheets becomes stronger, so that a fiber layer material with good strength can be obtained. . The above-mentioned fold height becomes the thickness of the fiber layer material, and the larger this thickness is, the more the fiber layer material of the present invention can be produced by slicing, but the heat can be uniformly spread to the inside during the heat bonding process. Becomes difficult. Therefore, a thickness of about 10 to 200 mm is usually preferable.

The fiber mass obtained as described above is cut in a direction substantially perpendicular to the fiber arrangement direction for use in a mat or a filter material. The angle between the fiber arrangement direction and the cutting direction can be arbitrarily selected depending on the application. The cutting is performed by slicing, and the thickness at that time is appropriately changed depending on the use of the fiber layer material. Since the front surface and / or the back surface of the fiber layer material of the present invention is a cut surface, the feeling is like a lawn and the friction coefficient is high. For example,
No. 56 for both warp and weft, and basis weight 165g / m
^{When the} dynamic friction coefficient for the fabric No. ² was measured, the cut surface was 1.2 to 1.7, and the cut surface was about 0.6 to 0.
It was about 2 times or more than 7.

FIG. 1 is a partially enlarged schematic perspective view of a fiber layer material obtained by the manufacturing method of the present invention. 1
Is a fiber layer material, and 2 is a fiber constituting the fiber layer material and arranged in the thickness direction. Reference numeral 3 is an adhesion portion between fibers. Reference numeral 4 denotes a surface of the fiber layer material, which is a cut surface, and in this surface, each fiber 2 constituting the fiber layer material is cut in a direction perpendicular to the fiber axis. As described above, in the fiber layer material of the present invention, the fibers are arranged in the thickness direction and the fibers are partially bonded to each other. Further, the front surface and / or the back surface of the fiber layer material is composed of an aggregate of transversely cut surfaces of each fiber constituting the fiber layer material.

The fiber layer material obtained by the production method of the present invention is
Since the fibers are arranged in the thickness direction and the fibers are partially adhered to each other, even if the fiber layer material receives a load in the thickness direction, each fiber acts as a spring, and elastic force and restoring force are exerted. The fiber layer material is suitable for a cushioning material because it has a good durability, is less likely to be settled, is extremely hard to be deformed as a whole of the fiber layer material, has a rigid feel, is hard to come loose, and has a good cushioning property. Further, the fiber layer material of the present invention has a grass-like surface feel and a high friction coefficient, and therefore, when used as a seat mat material for automobiles, for example, movement of other sheet materials provided on the surface thereof Has the advantage that it is suppressed, and because the fibers are arranged in the thickness direction, it has good breathability and does not sweat even after long-term use.

The fiber layer material obtained by the manufacturing method of the present invention is
Composed of fibers arranged in the thickness direction, it has elasticity with respect to the load in the thickness direction, good restoring force, little settling, and is hard to disperse, and moreover, the front surface and / or the back surface of the fiber layer material is the cut surface. Since this cut surface is composed of an aggregate of cut surfaces of each fiber, a fluid easily passes therethrough, which is suitable as various filter materials. When used for this fiber layer material filter material, the fluid smoothly enters from the front or back surface,
Since the fiber directions are aligned in the thickness direction, the fluid flowability is excellent.

When this fiber layer material is used in a filter, there are cases where the fluid is passed in the fiber direction and cases where the fluid is passed in the direction perpendicular to the fiber. From the point of having the above-mentioned properties, the fluid is passed in the fiber direction. It is particularly preferable when used so as to pass through. That is, when the conventional fiber layer material arranged in a direction substantially perpendicular to the thickness direction of the fiber layer is used for the filter, the filter material is compressed due to the pressure loss due to the flow of fluid, and the pressure loss increases quickly. However, there is a drawback in that a large amount of dust cannot be retained, but there is no such drawback when the fiber layer material of the present invention is used in a filter so that a fluid passes in the fiber direction. Therefore, the fiber layer material of the present invention, when used as a filter material, has a thickness of approximately 2 when compared with a filter material having a conventional fiber layer when compared at the same thickness.
A filter material with a life more than twice as long can be obtained. Further, when the fiber layer material of the present invention is used in a filter so that a fluid passes in a direction perpendicular to the fibers, the pressure loss is high and the dust holding amount is low, but the collection rate is high.

[0016]

Examples and Comparative Examples Example 1 An example of the present invention will be described with reference to the drawings. 100% polyester heat-bonding fibers with a thickness of 4 denier and a length of 51 mm (product name Melty, Unitika Ltd., core-sheath structure fibers with polyester fibers as the core) are used to lengthen the fibers in a card machine. A directional oriented web was made. This web was heat-treated in a heat treatment machine at 150 ° C. for 3 minutes to partially melt-bond the heat-bonded fibers to each other to obtain a sheet-shaped fiber layer. The sheet-like fiber layer has a basis weight of 52 g / m ² and a thickness of 0.86 mm, and the degree of fiber orientation is longitudinal (longitudinal).
91.7 calculated from the strength in the width direction and the strength in the width (width) direction
%Met.

As shown in FIG. 2, the sheet-like fiber layer 5 was fold-folded so that its fiber direction was vertical. The folds 6 and 6 between the folds, that is, the fold height was 45 mm. The fibers between the folded portions 6, 6 of the sheet-shaped fiber layer 5 arranged in a fold arrangement were arranged in the vertical direction. Next, the sheet-shaped fiber layer 5 in which the folds are arranged is compressed in a direction substantially perpendicular to the folding direction, that is, from the left and right,
It heat-processed for 10 minutes in a heat processing machine at 130 degreeC. An integrated fiber mass with a thickness of 45 mm and a basis weight of 2250 g / m ² was obtained. FIG. 3 is a perspective view of the fiber mass 7. The fibers of the adjacent sheet-shaped fiber layers 5 and 5 are also partially bonded by the heat treatment, and the sheet-shaped fiber layers 5 and 5 are firmly bonded to each other. Therefore, the fiber lump 7 was integrated. Further, since the constituent fibers of the fiber lump 7 are adhered to each other, the fiber lump 7 has rigidity, and has a feeling just like that of rigid polystyrene foam.

This fiber mass 7 was sliced in the direction perpendicular to the fiber arrangement direction, that is, in the horizontal direction in FIG. 3, to obtain the fiber layer material 1 of the present invention. In order to check the dispersibility of this fiber layer material, the fiber layer material 1 was sliced into a thickness of 35 mm, and tensile load was applied in the thickness direction of this fiber layer material, and the load until the fiber layer was dislocated was measured. The width was 2.0 kg / cm. Further, three kinds of fiber layer materials were prepared by slicing this fiber lump 7 into a thickness of about 10 mm, a thickness of about 5 mm and a thickness of about 3 mm in the direction perpendicular to the fiber arrangement direction. And the compression ratio,
Deformation rate, compression modulus, breathability and D.I. H. C was measured. The result is shown in No. 1 of Table 1. 1 to 3. The compression rate, deformation rate, and compression elastic modulus were measured according to JIS L1096. Further, the air permeability was in accordance with the Frazier method of JIS L1096. D. H. C, dust slaked lime speed 3
It is the amount of dust retained until the pressure loss rises to 150 mmAq after filtration at m / min.

Comparative Example For comparison, 100% of the polyester-based heat-bonded fibers used in Example 1 were used to prepare a web in which the fibers were arranged at random at random in a card machine.
Heat treatment for 3 minutes in a heat treatment machine at 0 ° C to melt and bond a part of the heat-bonded fiber, and the thickness is about 10 mm and about 5 m, respectively.
m, about 3 mm, basis weight about 500, 250, 160 g /
It was created three kinds of fiber sheet of m ^2. The constituent fibers of each fiber sheet were arranged at random in the direction perpendicular to the thickness direction. Physical properties of each fiber sheet were measured in the same manner as in Example 1. The result is shown in No. 1 of Table 1. 4 to 6.

For comparison, a 100% polyester heat-bonded fiber used in Example 1 was used to prepare a fiber web in which the fibers were oriented in the longitudinal direction by a card machine. This fiber web has a basis weight of 50 g / m ² and a thickness of 1.
The fiber orientation degree was 91.7% as calculated from the strength in the longitudinal (longitudinal) direction and the strength in the width (lateral) direction. This fibrous web was fold-processed as in Example 1 so that the fiber direction was vertical. The fold height was 45 mm. Next, the fold-fold arrangement was compressed in a direction substantially perpendicular to the folding direction, that is, from the left and right, and heat-treated at 130 ° C. in a heat treatment machine for 10 minutes. An integrated fiber mass having a thickness of 45 mm and a basis weight of 2000 g / m ² was obtained. This fiber mass was sliced to form a fiber layer material. In order to check the dispersibility of this fiber layer material, it was sliced into a fiber layer material having a thickness of 35 mm, tensile stress was applied in the thickness direction of this fiber layer material, and the load until the fiber layer was dislocated was measured, The width was 1.0 kg / cm. Compared to the fiber layer material of Example 1, it was easy to separate. Also,
This fiber mass is approximately 3 mm thick in the direction perpendicular to the fiber arrangement direction.
It was sliced into a fiber layer material. Then, the physical property values were measured in the same manner as in Example 1. The result is N in Table 1.
o. 7 shows.

[0021]

[Table 1]

As can be seen from Table 1, the fibrous layer material of the present invention is No. 1 of the comparative example. Despite having a lower density than the fiber sheets of Nos. 4 to 6, the compression rate and the deformation rate are extremely small, and the compression elastic modulus is large. The compressibility represents a settling state in the thickness direction when a constant load is applied, and a smaller value indicates less settling in the thickness direction. The deformation rate is a measure of how much the material is deformed from the original thickness when the material is unloaded after being loaded for a certain period of time, and the smaller this value is, the more the material can withstand repeated loading and the less the settling in the thickness direction.
Further, the compressive elastic modulus represents the restoring force in the thickness direction when the load is removed after being loaded for a certain period of time, and when the value is 100%, it means that the original thickness is completely restored.

[0023]

According to the method for producing a fiber layer material of the present invention, a fiber web containing heat-adhesive fibers and having fibers unidirectionally arranged is formed, and the fiber web is once melted or above the melting point of the heat-adhesive fibers. Since the fibers constituting the fiber web are partially adhered to each other to form a fiber sheet by producing the fiber layer material by using this fiber sheet as a raw material, the fiber layer material obtained is Compared with a fiber layer material produced using the above-mentioned fiber web as a raw material, a fiber layer material can be obtained which is rich in a rigid feel even when the same fiber is used as a raw material and which is hard to be separated even when a load is applied.

Further, when the above-mentioned fiber web in which the fibers are arranged in one direction is used as it is as a material, it is too bulky and the tension in the folding process cannot be applied so much that the folding process requires a long time. In addition, the fibers of the finished fiber mass cannot be sufficiently adhered to each other, and the fiber layer material is likely to be loosened, or the impact resilience is weak, and the fibers are easily set. Furthermore, since the number of folds cannot be increased, the amount of fibers becomes small and the characteristics as a filter material cannot be obtained. In the production method of the present invention, the fiber web is once heated to form a fiber sheet in which the fibers are heat-bonded to each other with the heat-adhesive fiber, so that the fiber sheet sufficiently withstands the tension at the time of folding, the folding step time can be shortened, In addition, a large number of folds can be obtained, compression and heating can be performed smoothly, and a fiber layer material that does not easily come loose can be obtained. The fiber layer material obtained by the manufacturing method of the present invention is suitable as a mat or a filter material.

[Brief description of drawings]

FIG. 1 is a perspective view of a fiber layer material of the present invention, which is partially enlarged schematically.

FIG. 2 is a perspective view showing a fold-folded state of the sheet-like fiber layer fiber layer in the process of manufacturing the fiber layer material of the present invention.

FIG. 3 is a perspective view of a fiber mass in the process of manufacturing the fiber layer material of the present invention.

FIG. 4 is a perspective view of a conventional fiber layer sheet, which is partially and schematically enlarged.

[Explanation of reference numerals] 1 fiber layer material, 2 fibers, 3 adhesive parts between fibers, 4
Cut surface 5 Sheet-like fiber layer, 6 Folded portion, 7 Fiber mass

Claims (1)

[Claims] 1. A fiber comprising a heat-adhesive fiber and forming a fiber web in which the fibers are arranged in one direction, and the fiber web is heated at a temperature higher than the melting point of the heat-adhesive fiber to form the fiber web. The fibers are partially adhered to each other to form a fibrous sheet, and then the fibrous sheet is folded in a direction perpendicular to the fiber arrangement direction, and then this folded product is compressed in a direction substantially perpendicular to the folding direction, and the heat-adhesive fiber is melted again. Production of a fiber layer material characterized by heating to a temperature above a point to partially bond the fibers to each other to form an integrated fiber mass, and then cutting the fiber mass in a direction substantially perpendicular to the fiber arrangement direction. Method.