KR20130077952A - Method for manufacturing polyester spunbond nonwoven fabric - Google Patents

Abstract

PURPOSE: A manufacturing method of polyester spunbond nonwoven fabric is provided to perform the thermal adhesion of webs at a low temperature, thereby improving tensile strength and reducing cost. CONSTITUTION: A manufacturing method of polyester spunbond nonwoven fabric capable of improving tensile strength of nonwoven fabric comprises; a step of conjugate-spinning a first polyester which has a melting point of 240-270°C and a second polyester which has a melting point of 180-220°C; a step of forming web with filaments which are formed by the conjugate spinning; and a step of heat-adhering web at 100°C or less.

Description

Method for manufacturing polyester spunbond nonwoven fabric {Method for Manufacturing Polyester Spunbond Nonwoven Fabric}

The present invention relates to a method for producing a polyester spunbond nonwoven fabric, and more specifically, to a polyester spunbond nonwoven fabric which can realize manufacturing cost reduction and tensile strength improvement of a nonwoven fabric by performing thermal bonding of webs at a relatively low temperature. It relates to a manufacturing method of.

Polyester spunbond nonwoven fabrics have high productivity, high strength and low thickness, and are being used in many industrial fields. Polyester spunbond nonwoven fabrics are used in civil engineering and building applications because of their high strength and excellent drainage properties, and are also widely used in automobiles for their low cost and excellent durability. In particular, it has recently been found that polyester spunbond nonwoven fabrics have excellent morphological stability and dust particle collecting ability, and have been widely used as filter materials.

Applicant has applied for a method for obtaining a polyester nonwoven fabric having high tensile strength as Korean Patent Application No. 10-2007-0134912, which is registered as No. 10-1079804 (hereinafter 'Patent' 804). The '804 patent forms a web in which a low melting point copolyester fiber and a regular polyester fiber are mixed through a mixed spinning of a low melting point copolyester and a regular polyester. It was intended to improve the tensile strength of the nonwoven fabric by melting the low melting copolyester fibers.

However, in order to melt the low melting copolyester fiber through the thermal bonding process, the thermal bonding process had to be carried out at least at the melting point of the low melting copolyester fiber, for example, at a temperature near 200 ° C.

Since the melting point of the low melting copolyester fibers is relatively lower than the melting point of regular polyester fibers but is still high when absolutely evaluated, high heating costs for the thermal bonding process are still a problem, as well as thermal bonding. The problem is that the heat applied to the web during the process causes damage to the regular polyester fibers, thereby lowering the tensile strength of the nonwoven fabric.

Accordingly, the present invention relates to a method for producing a polyester spunbond nonwoven fabric which can prevent problems caused by the above limitations and disadvantages of the related art.

One aspect of the present invention is to provide a method for producing a polyester spunbond nonwoven fabric which can realize manufacturing cost reduction and tensile strength improvement of a nonwoven fabric by performing thermal bonding of webs at a relatively low temperature.

In addition to the above-mentioned aspects of the present invention, other features and advantages of the present invention will be described below, or from such description will be clearly understood by those skilled in the art.

According to one aspect of the present invention as described above, the step of composite spinning the first polyester having a melting point of 240 to 270 ℃ and the second polyester having a melting point of 180 to 220 ℃, into the filaments formed by the composite spinning A method for producing a polyester spunbond nonwoven fabric is provided, comprising forming a web, and thermally bonding the web at 100 ° C. or lower.

The second polyester may be a copolyester prepared from copolymerized monomers comprising adipic acid, isophthalic acid, or mixtures thereof.

The amount of the second polyester of the first and second polyester used in the composite spinning step may be 5 to 20% by weight.

The filaments formed by the complex spinning may have a sheath and core structure. In this case, the first polyester forms a core component of the myelin sheath structure, and the second polyester forms a sheath component of the myelin sheath structure.

Optionally, the filaments formed by the composite spinning may have a side by side structure.

Optionally, the filaments formed by the composite spinning may have a sea and islands structure. In this case, the first polyester forms islands components of the island-in-the-sea structure, and the second polyester forms sea components of the island-in-sea structure.

The web forming step may include stretching the filaments formed by the composite spinning, opening the stretched filaments, and stacking the opened filaments.

The opening step may include ejecting the stretched filaments, colliding the ejected filaments with a colliding plate, and collecting the filaments diffused due to a collision with the colliding plate.

The foregoing general description of the present invention is intended to be illustrative of or explaining the present invention, but does not limit the scope of the present invention.

According to the manufacturing method of the present invention, since the web is formed by complex spinning a polyester having a low melting point of 180 to 220 ° C. and a regular polyester, each of the filaments constituting the web is a polyester having a low melting point and a regular polyester. It consists of. That is, only a part of the filament is the low melting polyester. Thus, when performing the thermal bonding process for the web, it is possible to melt the low melting point copolyester with significantly less heat than when the entire filament is a low melting point polyester.

That is, according to the present invention, the web bonding process may be performed at a temperature of 100 ° C. or lower, which is considerably lower than the melting point (180 ° C. to 220 ° C.) of the low-melting point polyester that is complex spun together with the regular polyester. Therefore, not only the cost required for the thermal bonding process can be significantly reduced compared with the prior art, but also the failure of the apparatus used for the thermal bonding can be reduced, and the maintenance and repair cost can be achieved simultaneously.

In addition, since the time required for each of the temperature rising and the temperature lowering after the thermal bonding process for the thermal bonding process is reduced, the entire nonwoven fabric manufacturing process may be efficiently performed.

In addition, since the thermal bonding process is performed at a relatively low temperature, damage to the fibers (exactly damage to the regular polyester portion of each fiber) due to heat applied during the thermal bonding process can be minimized, resulting in high tensile strength. A nonwoven fabric having can be obtained.

Other effects of the present invention will be described in detail below along with the related technical configurations.

Hereinafter, the manufacturing method of the polyester spunbond nonwoven fabric of this invention is demonstrated in detail.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Therefore, the present invention encompasses all changes and modifications that come within the scope of the invention as defined in the appended claims and equivalents thereof.

As used herein, the term 'composite spinning' is a concept that is distinguished from 'spinning and mixing' and 'mixing and spinning', and 'mixing spinning' refers to different materials, respectively. By spinning, a plurality of filaments formed of different materials are produced and mixed at the same time, respectively, whereas 'spinning' is a spinning method that allows two or more materials to be spun together to form a filament. On the other hand, 'mixed spinning' is a spinning method in which two or more materials are simply mixed and then the mixture is spun to form a filament, which is a big difference from 'composite spinning' in that the arrangement of each material in the produced filament cannot be controlled There is.

Method for producing a polyester spunbond nonwoven fabric of the present invention comprises the steps of composite spinning a first polyester having a melting point of 240 to 270 ℃ and a second polyester having a melting point of 180 to 220 ℃, filament formed by the composite spinning Forming a web with heat, and thermally bonding the web at 100 ° C. or lower.

The first polyester may include polyethylene terephthalate or polynaphthalene terephthalate.

The second polyester may include a copolymer in which a polyester of polyethylene terephthalate or polynaphthalene terephthalate is copolymerized with adipic acid or isophthalic acid. In this case, by adjusting the amount of adipic acid or isophthalic acid in the copolymerization process, the melting point of the second polyester can be adjusted to 180 to 220 ℃, more preferably 190 to 215 ℃. According to one embodiment of the present invention, the amount of adipic acid or isophthalic acid is 10 to 40 mol / wt%.

When the melting temperature of the second polyester having a low melting point exceeds 220 ° C., even if the web is formed by the composite spinning of the present invention, the temperature required for thermal bonding of the web rises to 150 ° C. or more.

On the other hand, when the melting temperature of the low-melting second polyester is less than 180 ° C, it is difficult to spin the low-melting second polyester at a high temperature higher than the melting point of the first polyester, and as a result, a lot of cutting occurs. The disadvantage is that Despite the above disadvantages, even if the non-woven fabric is manufactured by performing a heat bonding process at a low temperature of 100 ℃ or less, the shape change of the non-woven fabric may appear during long-term storage in the summer when the ambient temperature is high.

Therefore, the low melting second polyester used in the present invention preferably has a melting point of 180 to 220 ℃.

The filament formed by the composite spinning of the present invention has a sheath and core structure, a side by side structure, or a sea and islands structure. According to the present invention, the low melting point second polyester material is controlled in a portion of the filament (e.g., seam or sea component) that is most affected by external heat.

According to the present invention, since the low-melting second polyester is disposed at an outer portion of the filament that is most affected by external heat, almost all of the second polyester can be melted through a heat bonding process. . Accordingly, the amount of the second polyester in the first and second polyesters used in the composite spinning step is less than 5 to 15 to 30% by weight, which is the amount of low melting polyester in conventional mixed spinning or mixed spinning. To 20% by weight. That is, the present invention can reduce the production cost and improve the economical efficiency of the nonwoven fabric by reducing the use amount of the relatively low melting point of the second polyester without lowering the tensile strength of the nonwoven fabric.

According to an embodiment of the present invention, the web forming step may include stretching the filaments formed by the composite spinning, opening the stretched filaments, and laminating the opened filaments.

The opening step may include ejecting the stretched filaments, colliding the ejected filaments with a colliding plate, and collecting the filaments diffused due to a collision with the colliding plate on a conveyor belt. . The filaments collected on the conveyor belt are stacked to form a web.

Subsequently, the polyester spunbond nonwoven fabric of the present invention is produced by thermally bonding the web at 100 ° C. or lower.

The thermal bonding may be performed by an embossing method or a calendering method that presses the web between the heated rollers. Alternatively, the thermal bonding may be performed by a hot air method that allows hot air to pass through the web. In the present specification, the temperature of the heat bonding process refers to the temperature of the embossing roll, the temperature of the calender roll, or the temperature of hot air.

As described above, according to the present invention, since the first and second polyesters are composite spun, the individual filaments formed by the composite spinning include both the first and second polyesters. In this respect, the present invention is distinguished from the prior art in which different types of filaments are produced by interweaving a plurality of materials but each filament is formed of only one material.

As mentioned above, the thermal bonding of a web composed of filaments formed through intertwine spinning of regular polyester and low melting point polyester may result in a relatively high temperature at least near the melting point of the low melting polyester (eg, the low melting point). If the melting point of the polyester is 200 ° C, it should be carried out at (200 ± 5 ° C). This is because the entire filament formed only of the low melting point polyester should be melted through the heat bonding process.

On the other hand, according to the composite spinning of the present invention, since only a part of each filament is the second low melting point polyester, the low melting point second polyester even with considerably less calories than the whole filament is a low melting point polyester. Can be melted.

In addition, according to the composite spinning of the present invention, unlike the mixed spinning, the low-melting point second polyester material is disposed on the portion of the filament (for example, the outer portion) that can be most affected by external heat. Since it can be controlled, the low melting second polyester can be melted with a relatively small amount of heat.

As a result, the thermal bonding to the web of the present invention consisting of filaments formed through the composite spinning of the first and second polyesters is carried out at 100 ° C. or lower, which is significantly lower than the melting point (180 to 200 ° C.) of the second polyester. Can be. Therefore, not only the cost required for the thermal bonding process can be significantly reduced in comparison with the prior art, but also the failure of the apparatus used for the thermal bonding can be reduced, and the maintenance and repair costs can be simultaneously achieved. In addition, since the time required for each of the temperature rising and the temperature lowering after the thermal bonding process for the thermal bonding process is reduced, the entire nonwoven fabric manufacturing process may be efficiently performed. In addition, since the heat bonding process is performed at a relatively low temperature, damage to the fibers (preferably damage to the regular polyester component) due to heat applied during the heat bonding process can be minimized, and as a result, a nonwoven fabric having a high tensile strength Can be obtained.

According to an embodiment of the present invention, the filaments formed by the composite spinning may have a sheath and core structure. The first polyester forms a core component of the heart structure, and the low melting second polyester forms a sheath component of the heart structure. In the case of the present embodiment, only the supercomponent corresponding to the outer portion of the filament needs to be melted for thermal bonding of the web, so that the thermal bonding process may be performed at 100 ° C. or lower.

According to another embodiment of the present invention, the filaments formed by the composite spinning has a side by side structure. Even in this case, since only one side of the filament needs to be melted for thermal bonding of the web, the thermal bonding process may be performed at 100 ° C. or lower.

According to another embodiment of the present invention, the filaments formed by the composite spinning has a sea and islands (sea and islands) structure. The first polyester forms islands components of the island-in-the-sea structure, and the second polyester forms sea components of the island-in-the-sea structure. Also in this embodiment, only the sea component of the filament needs to be melted for thermal bonding of the web, so that the thermal bonding process may be performed at 100 ° C. or lower.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the following examples are only intended to help the understanding of the present invention should not be limited to the scope of the present invention.

Example  One

Regular polyester having an intrinsic viscosity (IV) of 0.655 and a melting point of 254 ° C., and a low melting point poly having a intrinsic viscosity of 0.745 and a melting point of 214 ° C. prepared by adding about 19 mol / wt% of adipic acid. The ester was melted at 288 ° C., respectively, and then sheath and core type composite spinning was performed. At this time, the amount of the low-melting polyester was 15% by weight.

The filament formed by the composite spinning was stretched and then discharged through a nozzle. The discharged filament collided with the impingement plate. The filaments diffused by the impact were collected on a conveyor belt and laminated in a web form. The filaments constituting the web had a linear density of about 9 denier.

The nonwoven was then completed by passing the web between 86 ° C. embossing rollers. The pressure between the embossing rollers in the thermal bonding process was 24 N / cm.

The nonwoven fabric thus prepared had a manufacturing width of 5.2 M and a surface density of 100 g / m 2.

Example  2

A nonwoven fabric was prepared in the same manner as in Example 1, except that the low melting polyester content was 10% by weight during the composite spinning.

Example  3

A nonwoven fabric was prepared in the same manner as in Example 1 except that the low melting point polyester was injected in the composite spinning 5% by weight.

Example  4

A nonwoven fabric was prepared in the same manner as in Example 1, except that the low melting polyester content was 20 wt% during the composite spinning.

Example  5

A nonwoven fabric was prepared in the same manner as in Example 1, except that the low melting polyester content was 4% by weight during the composite spinning.

Example  6

A nonwoven fabric was prepared in the same manner as in Example 1, except that the low melting polyester content was 24 wt% during the composite spinning.

Example  7

Side by side composite spinning was carried out instead of the deep sheath type composite spinning, and a nonwoven fabric was prepared in the same manner as in Example 1 except that the low melting polyester was added in an amount of 20% by weight. .

Example  8

An island-in-the-sea composite spinning (islands number: 12) was performed in place of the deep-core composite spinning, and a nonwoven fabric was prepared in the same manner as in Example 1 except that the low melting point polyester was 20 wt% in the composite spinning. .

Example  9

A low melting polyester having a melting point of 210 ° C. was used instead of a low melting polyester having a melting point of 214 ° C., and the same method as in Example 1 except that the heat bonding temperature (temperature of the embossing roller) was 82 ° C. Nonwoven fabrics were prepared.

Example  10

A low melting polyester having a melting point of 195 ° C. was used instead of a low melting polyester having a melting point of 214 ° C., and the same method as in Example 1 except that the heat bonding temperature (temperature of the embossing roller) was 63 ° C. Nonwoven fabrics were prepared.

Example  11

Instead of a low melting point polyester having a melting point of 214 ° C., a low melting point polyester having a melting point of 180 ° C. was used, and in the same manner as in Example 1 except that the heat bonding temperature (temperature of the embossing roller) was 55 ° C. Nonwoven fabrics were prepared.

Example  12

Instead of a low melting polyester having a melting point of 214 ° C., a low melting polyester having a melting point of 215 ° C. (a mixture of adipic acid and isophthalic acid was used for copolymerization with polyester, and the weight ratio was 50:50). A nonwoven fabric was prepared in the same manner as in Example 1 except that the thermal bonding temperature (temperature of the embossing roller) was 88 ° C.

Comparative example  One

Example 1 and except that it was spun alone with the regular polyester without using a low melting point polyester, the heat bonding temperature (temperature of the embossing roller) was 252 ℃, the pressure between the embossing rollers was 44N / cm In the same manner, a nonwoven fabric was produced.

Comparative example  2

Mixed spinning was carried out instead of the composite spinning, the thermal bonding temperature (temperature of the embossing roller) was 212 ℃, and the nonwoven fabric was prepared in the same manner as in Example 1 except that the pressure between the embossing rollers was 34N / cm. .

Comparative example  3

Composite spinning was carried out in the same manner as in Example 1 except that a low melting polyester having a melting point of 175 ° C. was used instead of a low melting polyester having a melting point of 214 ° C., but a non-woven fabric was produced by cutting. I could not.

Comparative example  4

A low melting polyester having a melting point of 224 ° C. was used instead of a low melting polyester having a melting point of 214 ° C., and the same method as in Example 1 except that the heat bonding temperature (temperature of the embossing roller) was 160 ° C. Nonwoven fabrics were prepared.

Tensile strength, elongation, and tear strength of the nonwoven fabrics prepared by the above Examples and Comparative Examples were measured according to the JIS L 1906 standard, which is a method of measuring the long fiber spunbond nonwoven fabric, and the results are shown in Table 1 below. Indicated.

Low melting point
PE
input
(weight%) radiation
Way Low melting point
PE
Melting point
(℃) Heat seal
Temperature
(℃) Heat seal
pressure
(N / cm) The tensile strength
(Kg / 5cm) Shindo
(%) Phosphorus strength
(kgf) MD CD MD CD MD CD Example 1 15 Cardiac
Compound spinning 214 86 24 38 36 43 48 8.8 9.3 Example 2 10 Cardiac
Compound spinning 214 86 24 34 35 40 45 9.3 8.8 Example 3 5 Cardiac
Compound spinning 214 86 24 32 30 38 42 8.2 8.5 Example 4 20 Cardiac
Compound spinning 214 86 24 37 36 45 46 8.4 8.2 Example 5 4 Cardiac
Compound spinning 214 86 24 24 22 23 28 4.9 5.5 Example 6 24 Cardiac
Compound spinning 214 86 24 35 33 45 44 7.1 7.3 Example 7 20 side by side
Compound spinning 214 86 24 32 33 41 40 8.1 8.5 Example 8 20 Island
Compound spinning
(12 degrees) 214 86 26 38 37 45 46 8.4 8.2 Example 9 15 Cardiac
Compound spinning 210 82 24 36 37 44 43 8.3 8.2 Example 10 15 Cardiac
Compound spinning 195 63 24 37 38 47 43 8.9 8.6 Example 11 15 Cardiac
Compound spinning 180 55 24 36 34 48 45 8.6 8.7 Example 12 15 Cardiac
Compound spinning 215 88 24 34 36 43 42 8.5 8.4 Comparative Example 1 0 Single spinning - 252 44 20 18 18 22 2.4 3.6 Comparative Example 2 15 Horn Island Spinning 214 212 34 26 24 23 22 2.8 2.7 Comparative Example 3 15 Cardiac
Compound spinning 175 Nonwoven fabric cannot be manufactured due to cutting Comparative Example 4 15 Cardiac
Compound spinning 224 160 24 32 27 35 37 5.7 5.9

(* Note: MD: Mechanical Direction, CD: Cross Direction)

Claims (8)

Composite spinning a first polyester having a melting point of 240 to 270 ° C. and a second polyester having a melting point of 180 to 220 ° C .;
Forming a web from the filaments formed by the composite spinning; And
Method for producing a polyester spunbond nonwoven fabric comprising the step of thermally bonding the web at 100 ℃ or less. The method of claim 1,
Wherein said second polyester is a copolyester prepared from a copolymerization monomer comprising adipic acid, isophthalic acid, or mixtures thereof. The method of claim 1,
The method of producing a polyester spunbond nonwoven fabric, characterized in that the amount of the second polyester of the first and second polyester used in the composite spinning step is 5 to 20% by weight. The method of claim 1,
The filaments formed by the composite spinning has a sheath and core structure,
The first polyester forms a core component of the myelin sheath structure,
The second polyester is a method of producing a polyester spunbond nonwoven fabric, characterized in that to form a sheath component of the sheath type structure. The method of claim 1,
Method for producing a polyester spunbond nonwoven fabric characterized in that the filaments formed by the composite spinning has a side by side structure. The method of claim 1,
The filaments formed by the composite spinning has a sea and islands structure,
The first polyester forms islands components of the island-in-the-sea structure,
And said second polyester forms a sea component of said island-in-the-sea structure. The method of claim 1,
The web forming step,
Stretching the filaments formed by the composite spinning;
Opening the stretched filaments; And
Laminating the opened filaments The manufacturing method of the polyester spunbond nonwoven fabric characterized in that it comprises a step. The method of claim 7, wherein
The opening step is
Ejecting the stretched filaments;
Colliding the discharged filaments with a collision plate; And
And collecting the filaments diffused due to the collision with the impingement plate.