JP2018080422A - Polyester continuous fiber nonwoven fabric, and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a nonwoven fabric high in a basis weight and permeability, and hard to be compressed in a thickness direction while maintaining gaps between fibers.SOLUTION: A polyester continuous fiber nonwoven fabric is composed of a polyester continuous fiber where the cross-sectional shape of the polyester continuous fiber is an approximately Y4 shape obtained by connecting Y-letters vertically and horizontally connected at lower ends, the single fiber fineness of the continuous fiber is not less than 10 dtex, the constituent fibers three-dimensionally entangles each other to integrate as a nonwoven fabric, the basis weight is not less than 70 g/m, and the bulk density at a 100 gf/cmload is not greater than 0.10 g/cc.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a high-rigidity polyester long-fiber nonwoven fabric and a method for producing the same, and particularly relates to a polyester long-fiber nonwoven fabric that is not easily deformed against compression, maintains the voids of the nonwoven fabric, and maintains high air permeability and a method for producing the same. Is.

  Conventionally, polyester nonwoven fabrics are used for various applications. In particular, since polyester fibers have higher rigidity than other synthetic fibers, polyester nonwoven fabrics comprising polyester fibers as constituent fibers are laminated and bonded to filter materials and used as supports.

  For example, Patent Document 1 discloses a nonwoven fabric used as a filter support, which is a nonwoven fabric composed of polyester-based continuous fibers composed of a low-melting component and a high-melting component, and is partially thermocompression bonded. A nonwoven fabric having high air permeability and excellent rigidity is disclosed.

However, since the nonwoven fabric of patent document 1 is improving the rigidity by carrying out partial thermocompression bonding, the space | gap between fibers is crushed by nonwoven fabric compression itself.
JP 2003-275519 A (Claims)

  The present inventor does not exhibit rigidity by crushing the gap between fibers by partially thermocompression bonding, but obtains a nonwoven fabric having high fabric weight and air permeability and excellent in rigidity while maintaining the gap between fibers. investigated.

By the way, this inventor developed the polyester nonwoven fabric with a special cross-sectional shape (Unexamined-Japanese-Patent No. 2013-76182). This is a non-woven fabric comprising polyester long fibers as a constituent fiber, and the cross-sectional shape of the polyester long fibers is connected to the top, bottom, left and right at the lower end of a substantially Y-shape.
It is a polyester nonwoven fabric characterized by its shape. Such a polyester nonwoven fabric has a characteristic of being highly rigid because it is composed of long fibers having a unique cross-sectional shape.

  When the inventor made a nonwoven fabric by specific means using the polyester long fibers having the above-mentioned unique cross-sectional shape, it was difficult to compress in the thickness direction, and a fiber that could maintain the inter-fiber void was obtained. Accordingly, an object of the present invention is to obtain a non-woven fabric that has a high basis weight and air permeability and is difficult to be compressed in the thickness direction while maintaining a gap between fibers.

That is, the present invention is a nonwoven fabric comprising polyester long fibers as a constituent fiber, and the cross-sectional shape of the polyester long fibers is connected to the upper, lower, left and right at the lower end of a substantially Y shape.
Shape (hereinafter referred to as “substantially Y4 shape”),
The single fiber fineness of the long fiber is 10 dtex or more, and the constituent fibers are entangled three-dimensionally and integrated as a nonwoven fabric,
The present invention relates to a polyester long-fiber nonwoven fabric characterized by having a basis weight of 70 g / m ² or more and a bulk density at a load of 100 g / cm ² of 0.10 g / cc or less.

  The polyester continuous fiber used in the present invention will be described. This long fiber is characterized by the cross-sectional shape of the fiber. This cross-sectional shape has four substantially Y-characters as shown in FIG. And it is connected to the upper and lower sides and the right and left at the lower end 1 of a substantially Y shape, and has a substantially Y4 shape as shown in FIG. This substantially Y4 shape is excellent in bulkiness by having four concave portions 2, eight convex portions 3, and four small concave portions 4. In addition, dust and the like are easily trapped at the four recesses 2 and are excellent in filter performance and dust catching property. Moreover, it is highly rigid by the substantially + character part 5 of the center, and the four substantially V-shaped parts 6 connected with each front-end | tip of the approximately + character part 5. In other words, it is not a simple shape such as a hexagon or a Y-shape, but a higher rigidity is achieved by a combination of the substantially + -shaped portion 5 and the substantially V-shaped portion 6 having high rigidity.

  The polyester continuous fiber may be composed of one kind of polyester, or may be a combination of a low-melting polyester and a high-melting polyester. When composed of one kind of polyester, it is preferably composed of polyethylene terephthalate because it is excellent in fiber strength and thermal stability. In the case of a combination of a low-melting polyester and a high-melting polyester, the substantially V-shaped portion 6 of the cross-sectional shape of the polyester long fiber is formed of the low-melting polyester, and the substantially + -shaped portion 5 is formed of the high-melting polyester. The composite type is preferable. When using composite polyester long fibers, only the low-melting polyester is softened or melted and temporarily heat-bonded to each other prior to the needle punching step to be described later, at the time of pre-bonding to maintain the shape. It is good to make it about.

  The single fiber fineness of the polyester long fiber is preferably 10 dtex or more. When the fineness is less than 10 dtex, the rigidity of the long fiber is lowered, and as a result, the rigidity of the polyester long fiber nonwoven fabric tends to be lowered. And if the rigidity of a long fiber falls, the deformation | transformation with respect to compression will become large. The details of the method for obtaining the polyester continuous fiber used in the present invention are described in detail in the above-mentioned JP-A-2013-76182.

  In the polyester long fiber nonwoven fabric of the present invention, the constituent fibers are integrated by being entangled three-dimensionally to maintain the form of the nonwoven fabric. As described above, since the long fibers having a unique cross-sectional shape are entangled with each other, the polyester long fiber nonwoven fabric of the present invention has a large gap between the fibers. It is bulky.

Such a nonwoven fabric entangled three-dimensionally can be obtained by subjecting a fiber web formed by collecting long fibers to needle punching. That is, a fiber web in which polyester long fibers are accumulated is prepared, needle punching is applied to the fiber web, and the fiber axis direction of the accumulated long fibers is also moved in the thickness direction to entangle the long fibers. Let The long fibers in the present invention are excellent in rigidity due to having a unique cross section. Therefore, by moving the fiber axis direction of such long fibers also in the thickness direction and entangle the fibers, the long fibers are high in the thickness direction. A non-woven fabric that has rigidity, undergoes little change in thickness with respect to compression, and can maintain voids between fibers is obtained. Needle punching may be performed from only one side of the fiber web or from both sides. The number of times of needle punching may be appropriately designed in consideration of the basis weight of the fiber web, but the number of punches is preferably about 30 to 100 punches / cm ² . In addition, it is good to use the thing formed by carrying out temporary heat bonding of the fibers for the fiber web formed by collecting the polyester long fibers in consideration of transportability and the like. The temporary heat bonding between the fibers is such that it can be easily unwound by the impact of the needle punching process.

The basis weight of the polyester long fiber nonwoven fabric of the present invention is 70 g / m ² or more. When the weight per unit area is less than 70 g / m ² , the number of constituent fibers is relatively reduced, so that fiber entanglement by the needle punching process is insufficient, and the polyester long fiber nonwoven fabric tends to have lower rigidity or insufficient strength. By setting the basis weight to 70 g / m ² or more, the effects of the present invention can be achieved more favorably, the more preferable basis weight is 100 g / m ² or more, and the more preferable basis weight is 200 g / m ² or more. The basis weight may be appropriately set according to the use of the long fiber nonwoven fabric of the present invention, but the upper limit is about 1000 g / m ² .

The polyester continuous fiber nonwoven fabric of the present invention has a bulk density of 0.10 g / cc or less at a load of 100 gf / cm ² . Since the nonwoven fabric of the present invention is difficult to compress in the thickness direction and easily maintains the initial inter-fiber gap, the bulk density is 0.10 g / cc or less even at 100 gf / cm ² load, It is possible to maintain the voids in the above and is excellent in bulkiness.

The bulk density at 100 gf / cm ² load is measured by the following method. That is, the thickness is measured according to JIS L1913 6.1 thickness (ISO method) A method. At that time, the sample is a standard sample, and 10 sample pieces of 10 cm in length and 10 cm in width are used, and the area of the presser hood is 10 cm ^2. The thickness is increased by applying a load of 100 gf / cm ^2. taking measurement. The thickness (μm) of the nonwoven fabric is determined from the measured average value of 10 points, and the bulk density is calculated as follows.
Bulk density (g / cc) = basis weight (g / m ² ) / thickness (μm)
Furthermore, in this invention, it is a bulk density measured by the method similar to the above, Comprising: When a load is 200 gf / cm < ² >, it is preferable that it is 0.13 g / cc or less.

  The polyester long fiber nonwoven fabric according to the present invention has bulkiness, is difficult to be compressed in the thickness direction against compression, and easily maintains the bulkiness, and can be applied to various uses. For example, since it has the characteristics of being highly rigid and having excellent dust removal properties, it can be suitably used as a filter material. That is, when used as a filter material, it is difficult to be compressed and has excellent handleability. Also, due to the excellent dust removability of the polyester long-fiber nonwoven fabric according to the present invention, when combined with a filter material such as a melt-blown nonwoven fabric or a nanofiber nonwoven fabric that collects fine dust and viruses, the role as a reinforcing material It can serve as a pre-filter that removes coarse dust. Moreover, since it is excellent in dust removal property, it is also suitable for use as a wiping material as a cleaning tool.

  In addition, it is suitable for use as various reinforcing materials such as ground reinforcement and rainwater separation, separation materials, and drainage materials by burying in the soil and laying in contact with the soil.

  The nonwoven fabric composed of polyester long fibers having a unique cross-sectional shape of the present invention is integrated by three-dimensional entanglement of the constituent fibers, so that the nonwoven fabric is bulky and has a high polyester length Since it is comprised with a fiber, it is hard to compress in the thickness direction, the space | gap between fibers can be maintained also by pressurization, and bulkiness can be maintained.

  The present invention will be described below based on examples, but the present invention is not limited to the examples. The present invention is a non-woven fabric integrated by forming polyester long fibers having a specific cross-sectional shape as constituent fibers, and the constituent fibers are entangled three-dimensionally, such a non-woven fabric is highly rigid, It should be interpreted as being based on the knowledge that it is difficult to compress in the thickness direction.

Example 1
Polyethylene terephthalate (relative viscosity [ηrel] 1.38, melting point 260 ° C.) was prepared by copolymerization using 100 mol% of terephthalic acid (TPA) as the dicarboxylic acid component and 100 mol% of ethylene glycol (EG) as the diol component. Then, melt spinning was performed using the nozzle holes shown in FIG. 3 at a spinning temperature of 285 ° C. and a single hole discharge rate of 8.33 g / min.

The filament group discharged from the nozzle hole was introduced into the air soccer inlet 2 m below and pulled so that the fineness of the polyester long fiber was 17 dtex. The polyester long fiber group discharged from the air soccer outlet was opened with a fiber opening device and then collected on a moving net conveyor to obtain a fiber web. This fiber web was heat-bonded with an embossing roll having a surface temperature of 190 ° C. (the area at the tip of each embossing protrusion was 0.7 mm ² and the area ratio of the embossing protrusion relative to the total area of the roll was 15%) and a flat roll. The polyester continuous fiber nonwoven web having a basis weight of 100 g / m ² was obtained by introducing into a dressing apparatus and temporarily heat-bonding in order to improve transportability under the condition of a linear pressure of 150 N / cm between both rolls.

Two sheets of the obtained polyester long fiber nonwoven web were laminated, and the laminated web was subjected to needle punching. The needle punching was performed from one side using a needle punching machine equipped with an organ needle (PPD-1 No. 40) under the conditions of a needle needle depth of 10 mm and a punch count of 40 punches / cm ² . The basis weight of the obtained polyester continuous fiber nonwoven fabric obtained by three-dimensionally entangled fibers was 216.9 g / m ² .

Examples 2 and 3
In Example 1, a web obtained by laminating three non-woven polyester long fiber nonwoven webs used in Example 1 was used (Example 2), and the provisional heat fusion used in Example 1 was used. The polyester long fiber nonwoven fabrics of Examples 2 and 3 were subjected to needle punching in the same manner as in Example 1 except that a web in which five polyester long fiber nonwoven webs were laminated was used (Example 3). Got. The basis weight of the obtained polyester long fiber nonwoven fabric of Example 2 obtained by three-dimensional entanglement of fibers was 310.2 g / m ² , and the basis weight of the polyester long fiber nonwoven fabric of Example 3 was 571.3 g / m ² . .

Comparative Example 1
Polyethylene terephthalate (relative viscosity [ηrel] 1.38, melting point 260 ° C.) was prepared by copolymerization using 100 mol% of terephthalic acid (TPA) as the dicarboxylic acid component and 100 mol% of ethylene glycol (EG) as the diol component. Then, melt spinning was performed using a nozzle hole having a hole diameter of 0.4 mm at a spinning temperature of 285 ° C. and a single hole discharge rate of 1.67 g / min.

The filament group discharged from the nozzle hole was introduced into the air soccer inlet 2 m below, and pulled so that the fineness of the polyester long fiber became 3.3 dtex. The polyester long fiber group discharged from the air soccer outlet was opened with a fiber opening device and then collected on a moving net conveyor to obtain a fiber web. This fiber web was heat-bonded with an embossing roll having a surface temperature of 190 ° C. (the area at the tip of each embossing protrusion was 0.7 mm ² and the area ratio of the embossing protrusion relative to the total area of the roll was 15%) and a flat roll. The polyester continuous fiber nonwoven web having a basis weight of 100 g / m ² was obtained by introducing into a dressing apparatus and temporarily heat-bonding in order to improve transportability under the condition of a linear pressure of 150 N / cm between both rolls.

Two sheets of the obtained polyester long fiber nonwoven web were laminated, and the laminated web was subjected to needle punching. The needle punching process was performed from both sides under the conditions of a needle needle depth of 10 mm and a single-sided punch density of 40 times / cm ² using a needle punch machine equipped with an organ needle (PPD-1 # 40). The basis weight of the obtained polyester continuous fiber nonwoven fabric obtained by three-dimensional entanglement of fibers was 235.2 g / m ² .

Comparative Example 2
In Comparative Example 1, the needle punching treatment was performed in the same manner as in Comparative Example 1 except that a web obtained by laminating three polyester long fiber nonwoven webs that were temporarily heat-sealed in Comparative Example 1 was used. The polyester long fiber nonwoven fabric of Comparative Example 2 was obtained. The basis weight of the polyester continuous fiber nonwoven fabric obtained in Comparative Example 2 obtained by three-dimensionally entanglement of fibers was 344.8 g / m ² .

About the polyester long fiber nonwoven fabric of obtained Examples 1-3 and Comparative Examples 1 and 2, the thickness and the bulk density in the state which applied various loads were calculated | required. And about the thickness and the thickness at the time of various loads, it converted into the thickness per unit weight 100g / m < ² >, and calculated | required the thickness per unit weight 100g / m < ² > at the time of a specific load.

As described above, the thickness and thickness under various loads were measured according to JIS L1913 6.1 thickness (ISO method) A method. The sample was 10 cm long by 10 cm wide from the standard sample. The sample piece was 10 points and the area of the presser hood was 10 cm ² . Load ^was set to ^{100gf / cm 2, 150gf / cm} 2, 200gf / cm 2, 4 kinds of 300 gf / cm ^2. In addition, the thickness (micrometer) of the nonwoven fabric was calculated | required from the measured average value of 10 points | pieces, and the bulk density was computed by the following formula.
Bulk density (g / cc) = basis weight (g / m ² ) / thickness (μm)

Moreover, the air permeability was measured for Examples 1 to 3 and Comparative Examples 1 and 2. The air permeability (cc / cm ² · sec) is based on JIS L 1096 “General Textile Test Method” using a Frazier type air permeability tester (DAIEI KAGAKUSEEIKI SEISAKUSHO LTD. The inclination type barometer was fixed at 12.7 mm, and the air permeability was measured.

   The results are shown in Table 1.

  As is clear from the comparison between the examples of the present invention and the comparative examples, the polyester long-fiber nonwoven fabrics according to the examples also maintain a gap between fibers because the thickness change when compressed and the bulk density is high. You can see that Moreover, the air permeability of the polyester long fiber nonwoven fabric according to the example was also higher than that of the comparative example.

It is the figure which showed one substantially Y character of the substantially Y4 shape which is the cross-sectional shape of the polyester long fiber used by this invention. It is the figure which showed the substantially Y4 shape which is the cross-sectional shape of the polyester continuous fiber in this invention. It is the figure which showed the Y4 type nozzle hole used for this invention.

DESCRIPTION OF SYMBOLS 1 Lower end of one substantially Y shape of the substantially Y4 shape which is the cross-sectional shape of a polyester continuous fiber 2 The recessed part formed in the substantially Y4 shape 3 The convex part formed in the substantially Y4 shape 4 The small recessed part formed in the substantially Y4 shape 5 Substantially + character in the approximately Y4 shape 6 Substantially V character in the approximately Y4 shape

Claims (4)

A nonwoven fabric comprising polyester long fibers as a constituent fiber, wherein the cross-sectional shape of the polyester long fibers is connected to the top, bottom, left and right at the lower end of a substantially Y-shape.
Shape (hereinafter referred to as “substantially Y4 shape”),
The single fiber fineness of the long fiber is 10 dtex or more, and the constituent fibers are entangled three-dimensionally and integrated as a nonwoven fabric,
A polyester long-fiber nonwoven fabric characterized by having a basis weight of 70 g / m ² or more and a bulk density at a load of 100 gf / cm ² of 0.10 g / cc or less.   The polyester continuous fiber nonwoven fabric according to claim 1, wherein the polyester is polyethylene terephthalate. The single fiber fineness is 10 dtex or more, and the cross-sectional shape of the long fiber is connected to the top, bottom, left and right at the lower end of a substantially Y-shape.
Polyester long fibers having a shape (hereinafter referred to as “substantially Y4 shape”), and a web in which the polyester long fibers are deposited is subjected to needle punching, and the long fibers are entangled three-dimensionally. The method for producing a polyester continuous fiber nonwoven fabric according to claim 1, wherein the polyester continuous fiber nonwoven fabric is integrated. The shape of the nozzle hole used when the polyester long fiber is obtained by melt spinning is connected vertically and horizontally at the lower end of the Y-shape, and the adjacent Y-shapes are parallel to each other and \
The method for producing a polyester continuous fiber nonwoven fabric according to claim 3, wherein the method is a shape (hereinafter referred to as "Y4 shape").