WO2023121212A1 - Polyester nonwoven fabric with suppressed reduction in physical properties by tufting process, method for manufacturing same, and backing fabric for carpet comprising same - Google Patents

Abstract

The present invention relates to a polyester nonwoven fabric with suppressed reduction in physical properties by a tufting process, a method for manufacturing same, and a backing fabric for a carpet, comprising same and, in particular, to: a polyester nonwoven fabric in which, by controlling the physical properties of fibers of a first component filament and a second filament, a reduction in physical properties is remarkably suppressed before/after a tufting process, thus enabling the manufacture of a carpet backing fabric with excellent mechanical properties; a method for manufacturing same; and a backing fabric for a carpet, manufactured thereby.

Description

Polyester non-woven fabric with suppressed reduction in physical properties by tufting process, method for manufacturing the same, and foam paper for carpet including the same

The present invention relates to a polyester nonwoven fabric in which reduction in physical properties due to a tufting process is suppressed, a method for manufacturing the same, and a foam fabric for carpet including the same. The present invention relates to a polyester nonwoven fabric capable of producing a foam paper for carpet with excellent mechanical properties by significantly suppressing the decrease in physical properties before and after the ting process, a manufacturing method thereof, and a foam paper for carpet produced thereby.

In general, a polyester-based nonwoven fabric made of polyester filament fibers is widely used as a carpet base fabric. When manufacturing a carpet using carpet foam paper, a tufting process in which carpet yarn is transplanted to the carpet foam paper by a needle is required.

In the tufting process, the filament fibers constituting the polyester-based nonwoven fabric are damaged by needles, and thus physical properties such as tensile strength and tear strength of the nonwoven fabric are deteriorated. As one of the methods for solving these disadvantages, Korean Patent Publication No. 1998-0061102 discloses that after forming filament fibers and a web using two polyester polymers, needle punching is performed, and a spun for carpet bubble paper is passed through a calender roll. A method for producing a bonded nonwoven fabric is exemplified.

However, in this method, not only is the overall manufacturing process complicated, but also damage to the filament fibers after the tufting process of planting the carpet yarn becomes more serious because the filament fibers are damaged in the process of binding the filament fibers by needle punching.

Therefore, the nonwoven fabric manufactured by this method still exhibits the disadvantage of greatly deteriorating physical properties after tufting, and is difficult to apply for carpet base paper.

In addition, Korean Patent Publication No. 2001-0053138 discloses a method of manufacturing carpet foam paper through a process of manufacturing deformed cross-section yarn by spinning polyester and polylactic acid (PLA) by a composite spinning method. However, since this method is not good in spinnability, spinning defects are likely to occur, and manufacturing costs increase due to the high price of polylactic acid.

Therefore, there is a continuous demand for a nonwoven fabric that can be manufactured with a simplified process and low manufacturing cost, and that can be preferably used as a carpet base material as it has good physical properties even after the tufting process and a manufacturing method thereof.

The present invention has been made to solve the above problems, and the problem to be solved by the present invention is to control the components and physical properties of the first component filament and the second component filament to significantly suppress the degradation of physical properties before and after the tufting process. It is to provide a polyester-based nonwoven fabric, a manufacturing method thereof, and a foam paper for carpets including the same.

In order to solve the above problems, the present invention is a first component filament comprising a first polyester having a melting point of 250 ℃ to 300 ℃; and

A second component filament comprising a second polyester having a melting point of 160 ° C to 220 ° C;

Polyester-based nonwoven fabric, characterized in that the stiffness before the tufting process measured by the measurement method specified in ASTM D 6125-97 is 100 mg to 300 mg in both the machine direction (MD) and the vertical direction (CD) provides

In a preferred embodiment of the present invention, the machine direction stiffness (S _MD ) and vertical direction stiffness (S _CD ) of the polyester-based nonwoven fabric before the tufting process may satisfy the following Conditional Expression 1).

1) 0.95 ≤ S _MD /S _CD ≤ 1.05

In a preferred embodiment of the present invention, the first polyester may have an intrinsic viscosity of 0.65 dl/g to 0.80 dl/g.

In a preferred embodiment of the present invention, the polyester-based nonwoven fabric may be formed by fusing the second component filaments.

In a preferred embodiment of the present invention, the second polyester is at least one acid component selected from terephthalic acid, dimethyl terephthalate, isophthalic acid, and dimethyl isophthalate, 1,4-butanediol (BD), ethylene glycol (EG ) and neopentyl glycol (NPG).

In a preferred embodiment of the present invention, the polyester-based nonwoven fabric has a deviation between the machine direction (MD) tensile strength (T _MD,0 ) and the vertical direction (CD) tensile strength (T _CD,0 ) before the tufting process. T _CD,0 × 0.05 or less,

After the tufting process, the reduction rate of tensile strength may be 60% or less in both the machine direction and the vertical direction.

In a preferred embodiment of the present invention, the polyester-based nonwoven fabric may have both T _MD,0 and T _CD,0 of 25 kgf/5cm to 35 kgf/5cm before the tufting process.

In a preferred embodiment of the present invention, the polyester-based nonwoven fabric may include the first component filaments and the second component filaments in a weight ratio of 85:15 to 90:10.

In a preferred embodiment of the present invention, the polyester-based nonwoven fabric may have a machine direction heat shrinkage of 1.5% or less and a vertical direction heat shrinkage of 1.0% or less measured according to the following measurement method.

[measurement method]

Draw a pattern of 20 cm × 20 cm on a nonwoven fabric specimen measuring 25 cm × 25 cm in the machine direction and the vertical direction, respectively, preheat it on a preheating plate at 180 ° C for 3 minutes using a mathis oven, and then take it out and measure the contracted length. to calculate the shrinkage rate.

In a preferred embodiment of the present invention, the polyester-based nonwoven fabric may have a tear strength of 7 kgf to 13 kgf in both the machine direction and the vertical direction before the tufting process.

In a preferred embodiment of the present invention, the polyester-based nonwoven fabric may satisfy the following Conditional Expressions 2) and 3).

2) IV ₂ > IV ₁

3) 0.05 ≤ (IV ₂ -IV ₁ )/IV ₁ ≤ 0.50

In Conditional Expressions 2) and 3), IV ₁ and IV ₂ represent the intrinsic viscosity of the first polyester and the intrinsic viscosity of the second polyester, respectively.

In a preferred embodiment of the present invention, the first component filament has a fineness of 7 denier to 10 denier, and the second component filament has a fineness of 2 deiner to 4 denier, respectively,

The number of filaments of the first component filaments may be 2 to 5 times the number of filaments of the second component filaments.

The present invention also provides a foam paper for carpets comprising the polyester-based nonwoven fabric.

The present invention also includes the steps of: 1) forming a mixed fiber web by laminating a web by mixing a first polyester having a melting point of 250 ° C to 300 ° C and a second polyester having a melting point of 160 ° C to 220 ° C; and

2) thermally bonding the mixed fiber web with hot air having a temperature of 0° C. to 10° C. or more above the melting point of the second polyester;

It provides a polyester-based nonwoven fabric manufacturing method characterized in that for producing a nonwoven fabric having both the bending strength in the machine direction and the stiffness in the vertical direction before the tufting process, including 100 mg to 300 mg.

In a preferred embodiment of the present invention, in step 1), the first polyester and the second polyester are drawn at a speed of 4,500 m/min to 5,200 m/min, respectively, to form the first component filament and the second component filament, respectively. can form

The polyester-based nonwoven fabric according to the present invention can provide a polyester-based nonwoven fabric that is excellently maintained in tensile strength, tear strength, etc. even after the tufting process. Therefore, the polyester-based nonwoven fabric of the present invention can be usefully used for carpet base paper and can implement excellent mechanical properties.

Hereinafter, the detailed configuration and effects of the present invention will be described.

As described above, the conventional nonwoven fabric for carpet base paper has disadvantages in that filaments are damaged in the tufting process during carpet manufacturing, resulting in deterioration in physical properties, poor spinnability of fibers, and high manufacturing cost.

In order to solve this problem, the present invention provides a first component filament comprising a first polyester having a melting point of 250 ° C to 300 ° C; and

A second component filament comprising a second polyester having a melting point of 160 ° C to 220 ° C;

Polyester-based nonwoven fabric, characterized in that the stiffness before the tufting process measured by the measurement method specified in ASTM D 6125-97 is 100 mg to 300 mg in both the machine direction (MD) and the vertical direction (CD) provides

By providing a combination of fibers having the above physical properties and a nonwoven fabric having the above physical properties, the present invention significantly suppresses a decrease in physical properties such as tear strength and tensile strength of the nonwoven fabric despite the tufting process for carpet manufacturing. It is possible to provide a polyester-based nonwoven fabric that can be.

The first component filament is produced by spinning high-melting polyester, and thus serves as a matrix fiber (filament) in the nonwoven fabric manufacturing process.

In addition, the second component filament is produced by spinning low-melting polyester, and thus serves as a binder fiber (filament) in the manufacturing process of nonwoven fabric.

If the melting point of the first polyester of the first component filament is less than 250 ° C, the melting point difference with the second polyester serving as a binder decreases, and the usable temperature range for spinning may be reduced. Conversely, when the melting point exceeds 300° C., thermal decomposition of the second polyester at the spinning temperature may occur.

In addition, when the melting point of the second polyester of the second component filament is less than 160° C., heat shrinkage may occur during post-processing of the carpet base fabric including the polyester-based nonwoven fabric, resulting in poor dimensional stability. Conversely, if the melting point exceeds 220 ° C, the heat shrinkage rate of the nonwoven fabric is stable and the sheet may not be deformed during the carpet manufacturing process. There is a slight difference in elongation with the coating solution to be applied. Such subtle differences are not a problem in products immediately after manufacture, but as the usage period of the carpet increases, the latent stress due to the difference in elongation between the coating material and the nonwoven fabric may cause deformation of the carpet.

In addition, if the stiffness of the nonwoven fabric is less than 100 mg, it has too soft properties to be used for carpets, so it is not well suited for carpets because it does not maintain its shape well, and if it exceeds 300 mg, excessively stiff results , there is a problem in that the physical properties of the nonwoven fabric are deteriorated due to damage or loss of fibers, generation of fluff, etc. during the tufting process. In addition, when the stiffness exceeds 300 mg, the nonwoven fabric is stiff and lacks flexibility, so wrinkles are easily generated, and workability may also deteriorate.

In a preferred embodiment of the present invention, the machine direction stiffness (S _MD ) and vertical direction stiffness (S _CD ) of the polyester-based nonwoven fabric before the tufting process may satisfy the following Conditional Expression 1).

1) 0.95 ≤ S _MD /S _CD ≤ 1.05

That is, the polyester-based nonwoven fabric according to the present invention exhibits almost similar stiffness in the machine direction and the vertical direction, and if the above conditional expression 1 is not satisfied, that is, the S _MD exceeds 1.05 times or 0.95 times the S _CD If it is less than, the physical properties of the polyester-based nonwoven fabric in the tufting process may be greatly deteriorated. Preferably, S _MD and S _CD may satisfy the following Conditional Expression 1-1).

1-1) 0.98 ≤ S _MD /S _CD ≤ 1.03

In a preferred embodiment of the present invention, the first polyester may have an intrinsic viscosity of 0.65 dl/g to 0.80 dl/g. If the intrinsic viscosity exceeds 0.80 dl/g, the tensile strength of the first component filament and the tear strength of the polyester nonwoven fabric increase, but the stiffness of the nonwoven fabric is excessively increased or the pressure of the spinneret increases rapidly. As a result, problems such as leakage of the molten first polyester polymer may occur. However, conversely, when the intrinsic viscosity is 0.65 dl/g or less, the tensile strength of the filament and the tear strength of the nonwoven fabric are lowered, and there may be a problem in that the tensile strength is greatly reduced after the tufting process.

In a preferred embodiment of the present invention, the polyester-based nonwoven fabric may be formed by fusing the second component filaments. Since the second polyester has a relatively low melting point compared to the first polyester, the second component filaments formed therefrom can be easily fused with the first component filaments when heat is applied. Therefore, according to the present invention in which the second component filaments are uniformly distributed in the nonwoven fabric together with the first component filaments, the first and second component filaments are easily adhered to each other even without a separate process such as needle punching. It can be made into a non-woven fabric.

Therefore, the nonwoven fabric manufacturing process can be simplified according to the present invention, and the first and second component filaments included in the finally produced nonwoven fabric of the present invention may not have any damage caused by the needle punching process. .

In a preferred embodiment of the present invention, the second polyester is at least one acid component selected from terephthalic acid, dimethyl terephthalate, isophthalic acid, and dimethyl isophthalate, 1,4-butanediol (BD), ethylene glycol (EG ) and neopentyl glycol (NPG).

However, the compound of acid component and diol component is not limited to the compounds listed above, and can be selected according to the purpose of the invention from compounds of acid component and diol component for polyester polymerization generally used in the art.

In a preferred embodiment of the present invention, the polyester-based nonwoven fabric has a deviation between the machine direction (MD) tensile strength (T _MD,0 ) and the vertical direction (CD) tensile strength (T _CD,0 ) before the tufting process. T _CD,0 × 0.05 or less, and the reduction rate of tensile strength after the tufting process may be 60% or less in both the machine direction and the vertical direction.

In the present invention, since the tensile strength in the machine direction and the vertical direction before the tufting process has a uniform tensile strength of 5% or less of the vertical tensile strength (T _CD,0 ), there is little difference in physical properties depending on the direction, During the tufting process, the defect rate can be greatly reduced, and after the tufting process, the reduction rate of tensile strength is less than 60% in both the machine direction and the vertical direction, so the deterioration of physical properties can be greatly suppressed.

If the tensile strength reduction rate exceeds 60%, it may not be suitable for use as a carpet base paper because the tensile strength of the nonwoven fabric is significantly lowered after the tufting process.

In a preferred embodiment of the present invention, the polyester-based nonwoven fabric may have both T _MD,0 and T _CD,0 of 25 kgf/5cm to 35 kgf/5cm before the tufting process.

If any one of the tensile strength in the machine direction or the vertical direction before the tufting process is 25 kgf / 5 cm or less, the tensile strength is lowered after the tufting process and may not be suitable for using the nonwoven fabric for carpet base paper. In addition, on the contrary, if the tensile strength before the tufting process exceeds 35 kgf/5cm in either the machine direction or the vertical direction, the stiffness of the nonwoven fabric becomes excessively high, rather it becomes vulnerable to wrinkles, etc., and workability is poor or the physical properties before and after the tufting process There may be a problem in which the decrease in is significant.

In a preferred embodiment of the present invention, the polyester-based nonwoven fabric may include the first component filaments and the second component filaments in a weight ratio of 85:15 to 90:10. If the content ratio of the second component filaments is less than 10% by weight, since the physical properties are similar to those of the nonwoven fabric composed of only the high melting point first component filaments, a nonwoven fabric satisfying the required strength cannot be manufactured, A separate process such as needle punching that causes filament breakage will be required for nonwoven fabric manufacturing.

On the other hand, when the content ratio of the filaments of the second component exceeds 15% by weight, the adhesive component in the nonwoven fabric becomes too large, so when the nonwoven fabric is used as a base fabric for carpet, filament damage will occur due to the tufting process, resulting in tough The deterioration of the properties of the bubble paper due to the tinting process will become serious.

In a preferred embodiment of the present invention, the polyester-based nonwoven fabric may have a machine direction heat shrinkage of 1.5% or less and a vertical direction heat shrinkage of 1.0% or less measured according to the following measurement method.

[measurement method]

Draw a pattern of 20 cm × 20 cm on a nonwoven fabric specimen measuring 25 cm × 25 cm in the machine direction and the vertical direction, respectively, preheat it on a preheating plate at 180 ° C for 3 minutes using a mathis oven, and then take it out and measure the contracted length. to calculate the shrinkage rate.

If the heat shrinkage in the machine direction exceeds 1.5% or the heat shrinkage in the vertical direction exceeds 1.0%, the dimensional stability of the manufactured nonwoven fabric may be poor and may not be suitable for use as a carpet base paper.

In a preferred embodiment of the present invention, the polyester-based nonwoven fabric may have a tear strength of 7 kgf to 13 kgf in both the machine direction and the vertical direction before the tufting process.

If the tear strength is less than 7 kgf in the machine direction or vertical direction, the non-woven fabric is damaged during the tufting process, such as tearing, or the tear strength is lowered after the tufting process. There may be problems, and if it exceeds 13 kgf, problems such as excessive increase in stiffness or decrease in tensile strength may occur.

In a preferred embodiment of the present invention, the polyester-based nonwoven fabric may satisfy the following Conditional Expressions 2) and 3).

2) IV ₂ > IV ₁

3) 0.05 ≤ (IV ₂ - IV ₁ )/IV ₁ ≤ 0.50

In Conditional Expressions 2) and 3), IV ₁ and IV ₂ represent the intrinsic viscosity of the first polyester and the intrinsic viscosity of the second polyester, respectively.

By satisfying Conditional Expressions 2) and 3), it is possible to satisfy bending strength, tensile strength, and tear strength of the nonwoven fabric before the tufting process for achieving the object of the present invention.

If the intrinsic viscosity of the second polyester is lower than the intrinsic viscosity of the first polyester, since it has a significantly lower melt viscosity than the first polyester at the spinning temperature, there may be a problem of spinnability due to the difference in viscosity, The variation may be 5% to 12% relative to the intrinsic viscosity of the first polyester. If the intrinsic viscosity of the second polyester is greater than that of the first polyester by more than 12%, the internal pressure of the extruder increases and the nozzle is blocked during melt-spinning of the second component filament, which causes problems in the process. may occur, and due to the segmentation of the manufactured yarn, the fiber properties may be lowered and the tear strength of the nonwoven fabric may be lowered. In addition, when the difference between the intrinsic viscosity of the second polyester and the intrinsic viscosity of the first polyester is less than 5%, the effect of improving the strength of the yarn due to the production of high-viscosity fibers may be insignificant.

In a preferred embodiment of the present invention, the first component filament has a fineness of 7 denier to 10 denier, the second component filament has a fineness of 2 denier to 4 denier, respectively, and the number of filaments of the first component filament is the second component filament It may be included in 2 to 5 times the number of filaments of.

If the fineness of the first component filaments is less than 7 denier, since the number of first component filaments per unit area increases, when the nonwoven fabric is used as a carpet base material and undergoes a tufting process, needles filaments will be significantly damaged, and as a result, deterioration of bubble paper properties due to the tufting process will become serious. On the other hand, if the fineness of the first filament exceeds 10 denier, the uniformity of the nonwoven fabric manufactured using this will be severely impaired and its commercial usefulness will be lost.

In addition, when the fineness of the second component filament is less than 2 deiner, the second component filament may be cut during the cooling process. On the other hand, when the fineness of the second component filaments exceeds 4 denier, cooling of the second component filaments is not properly performed in a cooling process (for example, a cooling process performed immediately after web formation), so that the second component filaments are not properly cooled. Adhesion between the component filaments will cause the uniformity of the nonwoven fabric to deteriorate, resulting in a loss of commercial usefulness of the nonwoven fabric.

The present invention also provides a foam paper for carpets comprising the polyester-based nonwoven fabric.

By having the configuration as described above, the polyester-based nonwoven fabric of the present invention can properly suppress filament breakage during the tufting process for transplanting carpet yarns to exhibit excellent physical properties even after the tufting process, providing carpet base paper having excellent physical properties can do. In addition, since the polyester-based nonwoven fabric can be easily manufactured by thermally bonding the filaments constituting it, the manufacturing process is easy and simple, and the manufacturing cost can also be greatly reduced.

Hereinafter, the manufacturing method of the polyester-based nonwoven fabric will be described in detail.

The present invention, 1) forming a mixed fiber web by laminating a web by mixing a first polyester having a melting point of 250 ° C to 300 ° C and a second polyester having a melting point of 160 ° C to 220 ° C; and

2) thermally bonding the mixed fiber web with hot air having a temperature of 0 ° C to 10 ° C higher than the melting point of the second polyester; It provides a method for producing a polyester-based nonwoven fabric, characterized in that for producing a nonwoven fabric of 100 mg to 300 mg.

The temperature of the hot air may preferably have a temperature of 0° C. to 5° C. or higher than the melting point of the second polyester.

In a preferred embodiment of the present invention, in step 1), the first polyester and the second polyester are drawn at a speed of 4,500 m/min to 5,200 m/min, respectively, to form the first component filament and the second component filament, respectively. can form

By stretching at such a speed, it is possible to obtain the first component filament and the second component filament having fineness within the above range.

Components and physical properties of each of the first component filament, the second component filament, and the first polyester and the second polyester are the same as those described for the polyester-based nonwoven fabric, so they will be omitted.

Other steps of the non-woven fabric manufacturing process can be performed through a general non-woven fabric manufacturing process method, which is within the range that a person skilled in the art can easily select and carry out.

Hereinafter, specific effects of the present invention will be described through specific examples. However, it should be understood that the scope of the present invention is not limited to the following examples, and the following examples are merely exemplary embodiments provided to aid understanding of the present invention.

<Example>

Example 1

Polyester for matrix filament (manufactured by Kolon Industries, Inc., polymerizing terephthalic acid (TPA) and ethylene glycol (EG)) with a melting point of 255 ° C and an intrinsic viscosity (I.V.) of 0.65 dl / g and a melting point of 212 ° C Low-melting copolyester for binder filaments with an intrinsic viscosity of 0.82 dl/g (manufactured by Kolon Industries Co., Ltd., copolymerization of terephthalic acid (TPA), isophthalic acid (IPA), adipic acid (AA) and ethylene glycol (EG)) using a continuous extruder After melting using a, each was discharged through the spinning nozzle at the bottom of the continuous extruder and mixed spinning to prepare a first row of mixed yarn for web. In the mixed yarn, the weight ratio of the matrix filament and the binder filament was 90:10, and the fineness of the matrix filament and the binder filament was 8.5 denier and 3.5 denier, respectively.

In addition, after solidifying the continuous filament discharged from the spinning nozzle with cooling air, it was stretched at a spinning speed of 5,000 m/min using a high-pressure air stretching device.

Thereafter, the prepared filament is laminated in the form of a web on a conveyor net by a conventional opening method, and then subjected to a calendering process using a heated smooth roll to impart smoothness and appropriate thickness, and binder filament A spunbond nonwoven fabric for carpet base paper having a weight per unit area of 100 g/m 2 was prepared by thermal bonding with hot air at a melting point of +3° C. of the melting point copolyester.

Example 2

A spunbond nonwoven fabric for carpet base paper was prepared in the same manner as in Example 1, except that the matrix filaments were spun using polyester having an intrinsic viscosity of 0.78 dl/g. did

Example 3

The binder filament was made of a low melting point copolyester (manufactured by Kolon Industries, Inc., copolymerized with terephthalic acid (TPA), isophthalic acid (IPA), adipic acid (AA) and ethylene glycol (EG)) having a melting point of 164 ° C. A spunbond nonwoven fabric for carpet base paper was prepared in the same manner as in Example 1, except that it was thermally bonded with hot air.

Example 4

A spunbond nonwoven fabric for carpet base paper was prepared in the same manner as in Example 1, except that the weight ratio of the matrix filament and the binder filament was adjusted to 85:15.

Examples 5 to 7

The same method as in Example 1 was used, except that the polyester of the matrix filament and the binder filament were different as shown in Table 1, and thermally bonded with hot air at a temperature of +3° C., the melting point of the copolyester for binder filament. Thus, a spunbond nonwoven fabric for carpet foam paper was prepared.

Comparative Example 1

A spunbond nonwoven fabric for carpet base paper was prepared in the same manner as in Example 1, except that polyester having an intrinsic viscosity of 0.57 dl/g was used as the matrix filament.

Comparative Example 2

The binder filament is changed to a copolyester having a melting point of 156 ° C. (manufactured by Kolon Industries, Inc., copolymerization of terephthalic acid (TPA), isophthalic acid (IPA), adipic acid (AA) and ethylene glycol (EG)) and hot air at 159 ° C. A spunbond nonwoven fabric for carpet base paper was prepared in the same manner as in Example 1, except that it was thermally bonded.

Comparative Example 3

A spunbond nonwoven fabric for carpet base paper was prepared in the same manner as in Example 1, except that the melting point of the binder filament was adjusted to 226° C. and thermally bonded with hot air at 229° C.

Comparative Example 4

A spunbond nonwoven fabric for carpet base paper was prepared in the same manner as in Example 1, except that the weight ratio of the matrix filament and the binder filament was changed to be 94:6.

Comparative Example 5

A spunbond nonwoven fabric for carpet base paper was prepared in the same manner as in Example 1, except that the weight ratio of the matrix filament and the binder filament was changed to be 80:20.

<Experimental example>

Experimental Example 1: Measurement of stiffness (mg) of nonwoven fabric

For the stiffness of the polyester nonwoven fabric prepared according to Examples and Comparative Examples, a Bending Resistance Tester manufactured by Gurley Precision Instruments (Troy, New York) was used according to the method specified in ASTM D 6125-97.

Experimental Example 2: Measurement of tear strength (kgf)

According to the KS K 0536 (Single Tongue) method, a specimen of 7.6 cm × 20 cm in size was cut from the spunbond nonwoven fabric and the tear strength was measured using a universal tensile tester (Instron) at a tensile speed of 300 mm / min.

Experimental Example 3: Measurement of tensile strength (kgf/5cm)

The tensile strength before the tufting process was measured using the measurement method specified in KS K 0521.

Specifically, a specimen having a width × length = 5 cm × 20 cm was fixed to a jig with a height of 5/5 cm using INSTRON's (USA) measuring equipment, and the tensile speed was measured at 200 mm/min.

The tensile strength after tufting was measured using the KS K 0521 method as described above after tufting using a small tufting machine having a width of 1.0 m.

At this time, the operating conditions of the tufting machine were pile height 5.0 mm, gauge 1.10 inch, stitch 1/13 inch, and operating speed 600 rpm, and the carpet yarn (BCF) used at this time was Hyosung Co., Ltd. A carpet in the form of a single loop was manufactured using 1200 denier 96 filament triangular cross-section yarn of nylon 6 material manufactured by

Experimental Example 4: Thermal contraction rate (%) measurement

Draw a pattern of 20 cm × 20 cm on a non-woven fabric specimen with a size of width × length = 25 cm × 25 cm. After preheating at 180 ° C. for 3 minutes on a preheating plate using a Mathis oven (Mathis oven, Daelim Starlet Co.), the shrinkage rate was calculated through the shrunk length.

The above experimental results are shown in Table 1 below, respectively.

division	first component melting point, IV, content (℃, dl/g, wt%)			second component melting point, IV, content (℃, dl/g, wt%)			strength (mg) MD/CD	tear strength (kgf) MD/CD	tensile strength (kgf/5cm) MD/CD			heat shrinkage rate (%) MD/CD
									tufting jeon	tufting after	decrease rate (%)
Example 1	255	0.65	90	212	0.82	10	229/ 234	9.4/ 9.9	31.7/ 33.7	14.0/ 18.1	56/ 46	0.5/ 0.0
Example 2	255	0.78	90	212	0.82	10	254/269	10.5/ 10.9	32.5/ 33.9	16.6/ 18.3	49/ 46	0.4/ 0.0
Example 3	255	0.65	90	164	0.82	10	197/204	11.2/ 11.5	30.4/ 31.1	16.7/ 18.0	45/ 42	0.9/ 0.2
Example 4	255	0.65	85	212	0.82	15	265/273	8.4/ 8.6	33.2/ 32.1	13.6/ 13.8	59/ 57	0.6/ 0.0
Example 5	267	0.69	90	201	0.79	10	248/260	8.1/ 8.3	31.6/ 33.0	16.4/ 16.2	48/ 51	0.7/ 0.0
Example 6	258	0.68	90	193	0.64	10	216/231	7.3/ 7.5	29.8/ 30.9	16.7/ 13.3	44/ 57	0.8/ 0.0
Example 7	252	0.66	90	218	0.74	10	257/284	8.6/ 9.1	28.4/ 29.2	9.4/ 11.1	67/ 62	0.6/ 0.1
Comparative Example 1	255	0.57	90	212	0.82	10	279/287	6.4/ 6.7	30.5/ 30.1	8.8/ 9.3	71/ 69	2.5/ 1.8
Comparative Example 2	255	0.65	90	156	0.82	10	185/193	11.5/ 11.7	29.9/ 32.2	16.7/ 19.6	44/ 39	3.1/ 2.9
Comparative Example 3	255	0.65	90	226	0.82	10	305/321	5.9/ 6.4	29.5/ 31.7	6.8/ 7.6	77/ 76	0.3/ 0.0
Comparative Example 4	255	0.65	94	212	0.82	6	213/222	10.3/ 9.8	15.8/ 17.2	8.7/ 8.9	45/ 48	0.6/ 0.0
Comparative Example 5	255	0.65	80	212	0.82	20	298/303	5.4/ 5.2	29.4/ 30.1	8.5/ 7.5	71/ 75	1.5/ 0.2

Referring to Table 1, in Comparative Example 1, the intrinsic viscosity of the first component filament is too low, the tear strength is low, and the tensile strength reduction rate of the nonwoven fabric before and after tufting is remarkably high, so it is suitable for use as a polyester nonwoven fabric for carpet foam paper. It can be seen that it does not

In addition, it can be seen that Comparative Example 2 has a problem that the melting point of the second component filament is too low, so that the heat shrinkage rate is high, and thus the dimensional stability of the nonwoven fabric is deteriorated.

In Comparative Example 3, as a result of the excessively high melting point of the second component filament, it can be seen that the nonwoven fabric has excessively high stiffness, low tear strength, and significantly high reduction in tensile strength after the tufting process.

In Comparative Example 4, it can be seen that the content of the second component filaments is too low, and the tensile strength of the nonwoven fabric is significantly low, resulting in poor physical properties.

In Comparative Example 5, it was confirmed that the content of the second component filament was too high, so that the stiffness of the nonwoven fabric was high and the tear strength was low, and the tensile strength was excessively reduced by the tufting process.

In addition, it was found that the nonwoven fabrics according to the Examples did not have a large tensile strength decrease rate before and after tufting and had a low heat shrinkage rate, so that they were suitable for use as carpet foam paper. However, in the case of Example 7, it was confirmed that the difference in physical properties between the machine direction and the vertical direction was large, and the rate of decrease in tensile strength before and after tufting was large. . However, the heat shrinkage rate is small and the tear strength is excellent. Therefore, it can be seen that the smaller the deviation in stiffness between the vertical and machine directions, the better the physical properties.

Claims (15)

1. a first component filament comprising a first polyester having a melting point of 250° C. to 300° C.; and

   A second component filament comprising a second polyester having a melting point of 160 ° C to 220 ° C;

   Polyester-based nonwoven fabric, characterized in that the stiffness before the tufting process measured by the measurement method specified in ASTM D 6125-97 is 100 mg to 300 mg in both the machine direction (MD) and the vertical direction (CD) .
2. According to claim 1,

   Polyester-based nonwoven fabric, characterized in that the machine direction stiffness ( _SMD ) and vertical direction stiffness (S _CD ) of the polyester nonwoven fabric before the tufting process satisfy the following Conditional Expression 1):

   1) 0.95 ≤ S _MD /S _CD ≤ 1.05.
3. According to claim 1,

   The first polyester is a polyester-based nonwoven fabric, characterized in that the intrinsic viscosity of 0.65 dl / g to 0.80 dl / g.
4. According to claim 1,

   A polyester-based nonwoven fabric, characterized in that formed by fusing the second component filaments.
5. According to claim 1,

   The second polyester,

   Copolymerization of at least one acid component selected from terephthalic acid, dimethyl terephthalate, isophthalic acid, and dimethyl isophthalate with at least one diol component selected from 1,4-butanediol (BD), ethylene glycol (EG) and neopentyl glycol (NPG) A polyester-based nonwoven fabric, characterized in that it is a copolyester formed by.
6. According to claim 1,

   The polyester nonwoven fabric has a deviation between the machine direction (MD) tensile strength (T _MD,0 ) and the vertical direction (CD) tensile strength (T _CD,0 ) before the tufting process is T _CD,0 × 0.05 or less,

   Polyester-based nonwoven fabric, characterized in that the reduction rate of tensile strength after the tufting process is 60% or less in both the machine direction and the vertical direction.
7. According to claim 6,

   The polyester-based nonwoven fabric is a polyester-based nonwoven fabric, characterized in that both T _MD,0 and T _CD,0 are 25 kgf / 5cm to 35 kgf / 5cm before the tufting process.
8. According to claim 1,

   The polyester-based nonwoven fabric comprises the first component filaments and the second component filaments in a weight ratio of 85:15 to 90:10.
9. According to claim 1,

   The polyester nonwoven fabric has a machine direction heat shrinkage of 1.5% or less and a vertical direction heat shrinkage of 1.0% or less, measured according to the following measurement method:

   [measurement method]

   Draw a pattern of 20 cm × 20 cm on a nonwoven fabric specimen measuring 25 cm × 25 cm in the machine direction and the vertical direction, respectively, preheat it on a preheating plate at 180 ° C for 3 minutes using a mathis oven, and then take it out and measure the contracted length. to calculate the shrinkage rate.
10. According to claim 1,

    The polyester-based nonwoven fabric is a polyester-based nonwoven fabric, characterized in that the tear strength before the tufting process is 7 kgf to 13 kgf in both the machine direction and the vertical direction.
11. According to claim 1,

    The polyester-based nonwoven fabric is a polyester-based nonwoven fabric, characterized in that it satisfies the following Conditional Expressions 2) and 3):

    2) IV ₂ > IV ₁

    3) 0.05 ≤ (IV ₂ - IV ₁ )/IV ₁ ≤ 0.50

    In Conditional Expressions 2) and 3), IV ₁ and IV ₂ represent the intrinsic viscosity of the first polyester and the intrinsic viscosity of the second polyester, respectively.
12. According to claim 1,

    The first component filament has a fineness of 7 denier to 10 denier, and the second component filament has a fineness of 2 denier to 4 denier, respectively,

    A polyester-based nonwoven fabric, characterized in that the number of filaments of the first component filaments is 2 to 5 times the number of filaments of the second component filaments.
13. Comprising the polyester-based nonwoven fabric according to any one of claims 1 to 12

    Bubble paper for carpet.
14. 1) forming a mixed fiber web by mixing a first polyester having a melting point of 250° C. to 300° C. and a second polyester having a melting point of 160° C. to 220° C. and laminating the web; and

    2) thermally bonding the mixed fiber web with hot air having a temperature of 0 ° C to 10 ° C higher than the melting point of the second polyester; A method for producing a polyester-based nonwoven fabric, characterized in that for producing a nonwoven fabric of 100 mg to 300 mg.
15. According to claim 14,

    In step 1), the first polyester and the second polyester are drawn at a rate of 4,500 m/min to 5,200 m/min, respectively, to form first component filaments and second component filaments, respectively. Non-woven fabric manufacturing method.