KR102617462B1 - Non-woven fabric, carpet and method for preparing for the same - Google Patents

Abstract

This application relates to non-woven fabrics, carpets, and methods for manufacturing the same. According to the present application, a nonwoven fabric, a carpet, and a method for manufacturing the same can be provided with excellent shape stability, such as improving the curling problem. In addition, the present application can provide a nonwoven fabric and a manufacturing method thereof that enable quantitative evaluation and prediction of morphological stability.

Description

Non-woven fabric, carpet and method for preparing for the same}

This application relates to non-woven fabrics, carpets, and methods for manufacturing the same. Specifically, this application relates to spunbond nonwoven fabrics, carpets, and methods for manufacturing the same.

Carpets are manufactured through a tufting process in which carpet yarn (BCF yarn) is planted on nonwoven fabric for foam paper. Additionally, the external forces (e.g., physical pressure or heat) that non-woven fabrics (foam paper) and carpets receive during the manufacturing process are significant.

For example, in the non-woven fabric manufacturing process, external forces such as heat, tension, and cooling are applied during the yarn manufacturing stage, and high temperature and pressure are required to join the web of non-woven fabric (e.g., fixing the web shape). Additionally, in the tufting process, the nonwoven fabric may be damaged as a hole is made by the needle, and in the back coating process, it may be subjected to heating and cooling.

The above manufacturing process imparts potential stress to non-woven fabrics and carpets, thereby reducing the shape stability and mechanical properties of non-woven fabrics and carpets.

One purpose of this application is to provide a nonwoven fabric and a method for manufacturing the same.

Another object of the present application is to provide a nonwoven fabric with improved dimensional stability and a method for manufacturing the same.

Another object of the present application is to provide a nonwoven fabric with excellent mechanical properties and a method for manufacturing the same.

Another purpose of the present application is to provide a nonwoven fabric for which quantitative evaluation and prediction of morphological stability is possible.

Another purpose of the present application is to provide a method for manufacturing nonwoven fabrics that can quantitatively evaluate and predict the shape stability of nonwoven fabrics, such as controlling and evaluating (or confirming) the potential stress index of nonwoven fabrics during the manufacturing process.

Another object of the present application is to provide a nonwoven fabric and a carpet containing the same.

The above and other objects of the present application can all be solved by the invention of the present application described in detail below.

In one example related to this application, this application relates to a method of making a nonwoven fabric. Specifically, the method relates to a method of producing long fiber spunbond nonwoven fabric.

According to the present application, the method includes the steps of bonding the web (eg, fixing the web form), applying an emulsion, and then applying heat to relieve latent stresses. More specifically, the method:

A first step of producing a web by melt spinning a high-melting point polyester having a melting point (T _H ) and a low-melting point polyester having a melting point (T _L ) lower than the melting point (T _H );

a second step of joining the web;

a third step of imparting an emulsion to the bonded web; and

A fourth step of applying heat so that the potential stress index of the emulsion-applied nonwoven fabric becomes 5.00 or less;

Includes. The above method can effectively reduce the potential stress remaining in the nonwoven fabric.

As a result of experimental confirmation, when the weight of the nonwoven fabric is low, the stress value tends to be relatively low, and in the case of high weight nonwoven fabric, the stress tends to be high. However, a relatively low stress does not necessarily mean that the degree of curl occurrence is less. Therefore, considering both the weight (basis weight) and stress values that affect the shape stability of the nonwoven fabric is meaningful in predicting the degree of curling of the final product, carpet, and reducing the curling occurrence during the nonwoven fabric manufacturing stage.

As a result of careful study of this point, the inventor of the present application found that when heat is applied to the emulsion-imparted nonwoven fabric so that the potential stress index can be adjusted to 5.00 or less, the mechanical properties (and uniformity thereof) of the nonwoven fabric and the carpet manufactured therefrom After confirming that both and shape stability can be secured at the same time, the present invention was completed.

As explained in the experimental example below, the potential stress index is the stress of the nonwoven fabric measured in accordance with DIN 53369 divided by the unit weight of the nonwoven fabric (g/m ² ). Specifically, the potential stress index is calculated by exposing the nonwoven fabric to a temperature of 180°C for less than 5 minutes according to DIN 53369, cooling the nonwoven fabric at room temperature for about 1 minute, and then calculating the measured cooling stress (cN) of the nonwoven fabric. It is divided by unit weight (g/m ² ) and is treated as a dimensionless constant. In some cases, stress (thermal stress) may be measured during heat treatment of the nonwoven fabric. At this time, the exposure time of the nonwoven fabric to heat at 180°C may be within 4 minutes, within 3 minutes, or within 2 minutes.

As such, the method of the present application includes the step of adjusting the potential stress index of the nonwoven fabric during the nonwoven fabric manufacturing process, and through this, the potential stress of the nonwoven fabric is evaluated (or confirmed) as a value at that stage, thereby improving the shape stability of the nonwoven fabric. Enables processes that can be performed to be evaluated and performed quantitatively. Therefore, prediction and evaluation of the dimensional stability of nonwoven fabrics can also be made quantitatively.

Meanwhile, in relation to the products, characteristics of the products, and process conditions for manufacturing the products mentioned in this specification, if they are affected by heat or temperature, unless specifically mentioned, the heat or temperature may be room temperature. At this time, “room temperature” refers to a temperature in a particularly reduced or non-heated state, and may mean, for example, a temperature within the range of 15 to 30°C.

Hereinafter, each step of the manufacturing method of this application will be described in detail.

The method includes a first step of producing a web by melt spinning a high melting point polyester having a melting point (T _H ) and a low melting point polyester having a melting point (T _L ) lower than the melting point (T _H ). .

The shape of the web is not particularly limited. For example, the web may be isotropic or anisotropic.

In one example, the method can produce a web comprising 80 to 92 weight percent high melt point polyester yarn and 8 to 20 weight percent low melt point polyester yarn. At this time, the term “yarn” may be used interchangeably with the term filament.

Specifically, the lower limit of the content of the low melting point polyester yarn is, for example, 8.5% by weight or more, 9.0% by weight or more, 9.5% by weight or more, 10.0% by weight or more, 10.5% by weight or more, 11.0% by weight or more, 11.5% by weight or more. , 12.0% by weight or more, 12.5% by weight or more, 13.0% by weight or more, 13.5% by weight or more, 14.0% by weight or more, 14.5% by weight or more, 15.0% by weight or more, 15.5% by weight or more, 16.0% by weight or more, 16.5% by weight or more , it may be 17.0% by weight or more, 17.5% by weight or more, or 18.0% by weight or more. And, the upper limit of the low melting point polyester yarn content is, for example, 19.5% by weight or less, 19.0% by weight or less, 18.5% by weight or less, 18.0% by weight or less, 17.5% by weight or less, 17.0% by weight or less, 16.5% by weight or less. , 16.0 wt% or less, 15.5 wt% or less, 15.0 wt% or less, 14.5 wt% or less, 14.0 wt% or less, 13.5 wt% or less, 13.0 wt% or less, 12.5 wt% or less, 12.0 wt% or less, 11.5 wt% or less , may be 11.0 wt% or less, 10.5 wt% or less, or 10.0 wt% or less. If the content of low-melting point polyester that performs the thermal adhesive function is less than the above range, the thermal adhesive effect is not sufficient. In addition, when the content of low-melting polyester exceeds the above range, the degree of contact between fibers increases and movement between fibers is restricted. Accordingly, when the needle penetrates the nonwoven fabric (or foam paper) during the tufting process, the degree of damage to the fibers increases and the tensile strength characteristics of the nonwoven fabric deteriorate.

In one example, according to the method, a web comprising the high melting point polyester yarn having a fineness of 7.0 to 10.0 denier can be produced. If the fineness of the high melting point polyester yarn is less than the above range, the filament is thin and the number of filaments per unit area is large, so filament damage may occur during the tufting process and the quality (e.g. uniformity) of the product may deteriorate. In addition, if the fineness of the high-melting polyester yarn exceeds the above range, it is difficult to manufacture a product of a uniform shape due to insufficient cooling of the filament, and the height uniformity of the BCF yarn may decrease during the tufting process. You can.

In one example, according to the method, a web comprising the low melting point polyester yarn having a fineness of 2.0 to 5.0 denier can be produced. If the fineness of the low-melting polyester yarn is less than the above range, spinnability is poor, and if it exceeds the above range, the quality (e.g. uniformity) of the product may deteriorate due to the bundle phenomenon where the filaments adhere to each other. .

In one example, according to the method, the high melting point polyester yarn having a fineness of 7.0 to 10.0 denier; And a web containing the low melting point polyester yarn having a fineness of 2.0 to 5.0 denier can be manufactured.

The fineness can be secured, for example, by adjusting the spinneret diameter of the spinneret used during spinning and the discharge amount during spinning.

In one example, according to the method, the ratio (N ₁ /N ₂ ) between the number of high melt point polyester yarns (N ₁ ) (number of filaments) to the number of low melt point polyester yarns (N ₂ ) is 2.0. Webs ranging from 5.0 to 5.0 can be produced. Specifically, the lower limit of the ratio (N ₁ /N ₂ ) may be, for example, 2.1 or more, 2.2 or more, 2.3 or more, 2.4 or more, or 2.5 or more, and the upper limit may be, for example, 4.5 or less, 4.0 or less, 3.5 or more. It may be less than or equal to 3.0. If the ratio exceeds the above range, that is, if the high-melting point component exceeds the low-melting point component, it is difficult to provide sufficient strength due to a lack of bonding points between filaments. On the other hand, if the ratio is below the above range, the number of bonding points increases and the degree of freedom between filaments (e.g., movement between fibers) is limited, which can lead to damage to the fibers, for example, in the tufting process. can cause

In one example, the melting point (T _H ) of the high melting point polyester may be 250°C or higher. Specifically, the lower limit of the melting point (T _H ) of the high melting point polyester may be, for example, 255°C or higher, 260°C or higher, 265°C or higher, or 270°C or higher. The upper limit of the melting point (T _H ) of the high melting point polyester is not particularly limited, but may be, for example, 290 ℃ or less, 285 ℃ or less, 280 ℃ or less, 275 ℃ or less, 270 ℃ or less, 265 ℃ or less, or 260 ℃ or less. there is.

In one example, the melting point (T _L ) of the low melting point polyester may be less than 250°C. Specifically, the upper limit of the melting point ( _TL ) of the low melting point polyester is, for example, 245 ℃ or less, 240 ℃ or less, 235 ℃ or less, 230 ℃ or less, 225 ℃ or less, 220 ℃ or less, 215 ℃ or less, 210 ℃. Hereinafter, it may be 205°C or less, 200°C or less, 195°C or less, 180°C or less, 175°C or less, 170°C or less, 165°C or less, 160°C or less, or 155°C or less. And the lower limit is, for example, above 150℃, above 155℃, above 160℃, above 165℃, above 170℃, above 175℃, above 180℃, above 185℃, above 190℃, above 195℃, above 200℃. It may be above 205°C, above 210°C, above 215°C, above 220°C, above 225°C or above 230°C. If the melting point temperature of the low melting point polyester is below the above range, the low melting point polyester component is likely to melt due to heat applied during the process related to the nonwoven fabric, and thus fracture and heat shrinkage of the nonwoven fabric (or foam paper) are likely to occur. In addition, when the melting point temperature of the low-melting polyester exceeds the above range, the flexibility of the nonwoven fabric decreases and the difference in elongation with the coating resin used in carpet production increases, which causes the edges of the carpet to lift as the carpet usage period elapses. It causes worsening problems.

In one example, the intrinsic viscosity (IV) of the high melting point polyester may be 0.640 or more. For example, the lower intrinsic viscosity limit of the high melting point polyester may be, for example, 0.645 or more or 0.650 or more. The upper limit is not particularly limited, but may be, for example, 0.700 or less.

In one example, the intrinsic viscosity (IV) of the low melting point polyester may be 0.725 or more. Specifically, the lower intrinsic viscosity limit of the low melting point polyester may be, for example, 0.750 or more, 0.800 or more, 0.850 or more, or 0.900 or more. The upper limit is not particularly limited, but may be, for example, 0.950 or less.

Regarding the high melting point and low melting point polyester, the type of polyester is not particularly limited. For example, polyester such as polyethylene terephthalate, polybutylene terephthalate, polynaphthalene terephthalate, etc. may be used. Specifically, at least one or more of the polyesters listed above may be included in the web as a polyester component.

In one example, the low melting point polyester may be a copolyester. For example, the low melting point polyester may be a polyester copolymerized with adipic acid, a polyester copolymerized with isophthalic acid, or a polyester copolymerized with adipic acid and isophthalate. These copolymers can be manufactured by adding copolymerization monomers such as adipic acid or isophthalic acid during the polymerization process.

In one example, the spinning may be performed at a temperature higher than the melting point (T _H ) of the high melting point polyester (e.g., a temperature of 260° C. or higher). This radiation can be accomplished using known equipment.

Although not particularly limited, the spinning may be performed in a speed range of 3500 to 6000 m/min.

In one example, the two types of polyester can be cooled simultaneously by spinning through respective holes in the same or different nozzles of the spinneret, resulting in solidification. The cooling method is not particularly limited and can be achieved, for example, by using cooling air at an appropriate temperature or atmospheric temperature (room temperature).

In one example, the filament may be drawn at a predetermined draw ratio. For example, the cooled filament can be drawn at a predetermined spinning speed, and each filament can be divided at regular intervals.

The method includes a second step of joining the web. Specifically, the second step may be a step of combining the web by applying heat to the web. By this step, the webs can be combined and a so-called shape-fixed nonwoven fabric can be obtained.

Applying heat to the web to bind it together can be accomplished by known methods. For example, rolls (e.g., calendar rolls or emboss rolls) or rollers or hot air through (HAT) may be used. At this time, pressurization may also be performed. The shape of the roll, the method of applying hot air, and the means or method for maintaining each heat bonding temperature (or providing heat to the web) can be appropriately selected by a person skilled in the art from known techniques.

In one example, the method may bond the web by passing the web through a roll having a first thermal bonding temperature (T ₁ ) and applying a second thermal bonding temperature (T ₂ ) to the web after passing the roll. there is. That is, specifically, in the second step, the web is passed through a roll maintaining the first thermal bonding temperature (T ₁ ), and the second thermal bonding temperature (T ₂ ) is applied by hot air to the web that has passed through the roll. It can be done. At this time, the first thermal bonding temperature (T ₁ ) may be a temperature lower than the second thermal bonding temperature (T ₂ ). Although not particularly limited, the web may pass between two rolls, in which case the web may be pressed between the two rolls.

In one example, the second thermal bonding temperature (T ₂ ) caused by the hot air may be equal to or higher than the first thermal bonding temperature (T ₁ ).

In one example, the first thermal bonding temperature (T ₁ ) may be in the range of 120 to 190 °C. Appropriate dimensional stability of the nonwoven fabric can be imparted at that temperature.

In one example, the second thermal bonding temperature (T ₂ ) by the hot air may be in the range of 140 to 240 °C. Appropriate dimensional stability of the nonwoven fabric can be imparted at that temperature.

In one example, the second thermal bonding temperature (T ₂ ) may be higher than the first thermal bonding temperature (T ₁ ). Specifically, the temperature difference between the first thermal bonding temperature (T ₁ ) and the second thermal bonding temperature (T ₂ ) may be in the range of 20 to 60° C. (T ₂ > T ₁ ). Appropriate dimensional stability of the nonwoven fabric can be imparted at that temperature.

The method includes a third step of imparting (coating) an emulsion to the bonded web (e.g., nonwoven).

The emulsion can form a film on the surface of the web (non-woven fabric) or the filaments forming it. The film can reduce friction between the needle and the nonwoven fabric that occurs when the needle penetrates in the subsequent tufting process, thereby preventing damage to the web or the fibers forming it. Additionally, because heat generation due to friction is reduced through the emulsion film, the lifespan of the needle may be extended.

In one example, the emulsion may be applied (coated) to the bonded web (or the filaments forming it) in an amount of 0.05% by weight or more based on 100% by weight of the total weight of the nonwoven fabric. At this time, the total weight of the nonwoven fabric, which is the basis for the emulsion content, is, for example, the weight of the nonwoven fabric to which the emulsion was applied in step 3, the weight of the nonwoven fabric that went through the web bonding step, or the weight of the nonwoven fabric manufactured by performing step 4 described below. It may be the weight of the nonwoven fabric. Specifically, the lower limit of the content of the emulsion is, for example, 0.1% by weight or more, 0.15% by weight or more, 0.20% by weight or more, 0.25% by weight or more, 0.30% by weight or more, 0.35% by weight or more, 0.40% by weight or more, 0.45% by weight. % or more or 0.50% by weight or more. And, the upper limit of the content of the emulsion is, for example, 5.0% by weight or less, 4.5% by weight or less, 4.0% by weight or less, 3.5% by weight or less, 3.0% by weight or less, 2.5% by weight or less, 2.0% by weight or less, 1.5% by weight. It may be less than or equal to 1.0% by weight. If the content of the emulsion is less than the above range, the emulsion does not penetrate uniformly into the filaments forming the nonwoven fabric due to the insufficient content of the emulsion, making it difficult to form a sufficient emulsion film, and as a result, the filaments may be damaged during the tufting process. . Additionally, if a small amount of emulsion is used, the tufting process deteriorates and BCF yarn falls out. Additionally, if the content of the emulsion exceeds the above range, slippage increases, making it unsuitable for the winding process, and tension control is difficult. Furthermore, excess emulsion adheres to the needle bar used in the tufting process, and foreign substances such as dust accumulate on the emulsion adhered to the needle bar, which may prevent the carpet yarns from being planted at even intervals in the tufting process. .

The type of emulsion that can be used is not particularly limited. For example, the oil may be a silicone-based oil or an ester-based oil.

The method includes a fourth step of applying heat to the bonded web or emulsion-imparted nonwoven fabric so that the potential stress index is 5.00 or less. The inventor of the present application experimentally confirmed that when the potential stress index exceeds 5.00, the shape stability is not good, such as the degree of curling of the product is severe, as confirmed in the experimental examples below. The potential stress index is calculated by exposing the nonwoven fabric to a temperature of 180°C for less than 5 minutes in accordance with DIN 53369, then cooling the nonwoven fabric at room temperature for about 1 minute, and calculating the cooling stress (cN) measured by the unit weight of the nonwoven fabric. It can be calculated by dividing by (g/m ² ).

In one example, the potential stress index of the combined web (nonwoven fabric) may be 5.00 or less in MD (machine direction or mechanical).

In one example, the potential stress index of the bonded web (nonwoven fabric) may be 5.00 or less in CD (cross direction, machine vertical direction).

In one example, the potential stress index of the bonded web (nonwoven) may be less than or equal to 5.0 in MD and CD.

Specifically, in MD and/or CD, the upper limit of the potential stress index is, for example, 4.9 or less, 4.8 or less, 4.7 or less, 4.6 or less, 4.5 or less, 4.4 or less, 4.3 or less, 4.2 or less, 4.1 or less, or 4.0 or less. You can. And, the lower limit of the potential stress index may be, for example, 1.5 or more, 2.0 or more, 2.5 or more, 3.0 or more, or 3.5 or more.

In one example, the step of providing heat to relax the (potential) stress may be performed at a predetermined temperature (T ₃ ). Specifically, the step of relaxing stress by applying heat may be performed at a temperature (T ₃ ) that satisfies the equation 1 below.

[Relationship 1]

20 ℃ ≤ melting point of low-melting polyester (T _L ) - temperature (T ₃ ) ≤ 60 ℃

That is, the melting point (T _L ) of the low melting point polyester is greater than the temperature (T ₃ ), and the difference between the melting point (T _L ) and the temperature (T ₃ ) of the low melting point polyester may be in the range of 20 to 60°C.

When the above 4 steps are performed while applying heat at a temperature (T ₃ ) that satisfies Relational Equation 1, not only the coated emulsion is dried, but also the process of manufacturing a nonwoven fabric (e.g., a heat bonding step to bond a web, etc.) ), the potential stress imparted to the nonwoven fabric (or web) can be effectively reduced. Accordingly, the shape instability of the product (e.g. curling or edge lifting) caused by latent stress can be improved.

Specifically, the lower limit of the temperature difference (ΔT = T _L - T ₃ ) is, for example, 25 ℃ or more, 30 ℃ or more, 35 ℃ or more, 40 ℃ or more, 45 ℃ or more, 50 ℃ or more, or 55 ℃ or more. The upper limit may be, for example, 55°C or less, 50°C or less, 45°C or less, 40°C or less, 35°C or less, 30°C or less, or 25°C or less. If the temperature difference (△T = T _L - T ₃ ) is less than the above range, the stiffness of the nonwoven fabric may increase and the tufting performance may decrease, the width shrinkage of the nonwoven fabric may increase, and the initial physical properties of the nonwoven fabric may increase. Due to severe deformation, it is difficult to use non-woven fabric as a base paper for tile carpets. In particular, when the temperature difference (△T = T _L - T ₃ ) is given, the tearing strength of the nonwoven fabric is significantly reduced, leading to the problem of tearing of the tile carpet base paper after tufting. Conversely, when the temperature difference (ΔT = T _L - T ₃ ) exceeds the above range, it is difficult to effectively reduce the potential stress.

The method of providing heat at a temperature (T ₃ ) that satisfies the above relational equation 1 is not particularly limited. For example, known means or methods, such as using a cylinder dryer or applying hot air, may be considered to provide a temperature (T ₃ ) that satisfies the above relational equation 1.

In one example, the temperature (T ₃ ) at which the step of relaxing stress by applying heat is performed may satisfy Equation 2 below. Considering the entire process of manufacturing nonwoven fabric, it is advantageous for the temperature (T ₃ ) to satisfy relational equation 2 in alleviating potential stress.

[Relational Expression 2]

First heat bonding temperature (T ₁ ) ≤ temperature (T ₃ ) ≤ second heat bonding temperature (T ₂ )

In one example, the step of relaxing stress by applying heat may be performed at the temperature T ₃ for 10 to 130 seconds. For example, the time for relaxing the stress by applying heat at the temperature (T ₃ ) is 20 seconds or more, 30 seconds or more, 40 seconds or more, 50 seconds or more, 60 seconds or more, 70 seconds or more, and 80 seconds. It may be longer than 90 seconds, longer than 100 seconds, longer than 110 seconds, or longer than 120 seconds. And the upper limit may be, for example, 120 seconds or less, 110 seconds or less, 100 seconds or less, 90 seconds or less, 80 seconds or less, 70 seconds or less, 60 seconds or less, 50 seconds or less, 40 seconds or less, or 30 seconds or less. . If the time is less than the above range, the nonwoven fabric cannot be sufficiently relaxed, so the effect of re-heat treatment cannot be sufficiently obtained. If the time exceeds the above range, not only may the physical properties of the nonwoven fabric or the foam paper manufactured therefrom be deformed, but the production equipment may become too large, resulting in a decrease in productivity and an increase in manufacturing costs.

In one example, the thickness of the nonwoven fabric produced according to the above method may be within the range of 0.20 to 0.60 mm. Specifically, the lower limit of the thickness of the nonwoven fabric may be, for example, 0.25 mm or more, 0.30 mm or more, 0.35 mm or more, or 0.40 mm or more, and the upper limit may be, for example, 0.55 mm or less, 0.50 mm or less, 0.45 mm or less, or 0.40 mm or less. It may be less than mm.

In one example, the unit weight, that is, the basis weight, of the nonwoven fabric manufactured according to the above method may be 70 to 140 g/m ² . Specifically, the lower basis weight limit of the bonded web is, for example, 75 g/m 2 or more, 80 g/m ² or more, 85 g/m ² or more, 90 g/m ² or more, 95 g/m ² or more, It may be 100 g/m ² or more or 105 g/m ² or more, with the upper limit being, for example, 135 g/m ² or less, 130 g/m ² or less, 125 g/m ² or less, 120 g/m ² or less. , 115 g/m ² or less, 110 g/m ² or less, 105 g/m ² or less, 100 g/m ² or less, 95 g/m ² or less, or 90 g/m ^{2 or} less. When the above range is satisfied, an appropriate level of lightness and mechanical properties can be secured.

In one example, a nonwoven fabric produced according to the above method may simultaneously have the above-described thickness and basis weight. For example, the nonwoven fabric may have a thickness of 0.30 to 0.40 mm and a basis weight of 85 to 95 g/m ² . Alternatively, the nonwoven fabric may have, for example, a thickness of 0.35 to 0.55 mm and a basis weight of 90 to 120 g/m ² .

In another example related to this application, this application relates to nonwoven fabrics. The nonwoven fabric can be provided by the manufacturing method described above.

The nonwoven fabric includes high melting point polyester yarn and low melting point polyester yarn fused together; and an emulsion, and the potential stress index may be satisfied at 5.00 or less. Specifically, the high melting point polyester yarn and the low melting point polyester yarn fused together form a nonwoven fabric (or web), and the emulsion can be coated on each polyester yarn or nonwoven fabric (or web) to form a film. . In addition, the potential stress index in MD and/or CD of the nonwoven fabric may be, for example, 5.0 or less. The specific potential stress index is as described in the content related to the manufacturing method.

In one example, the potential stress index of the bonded web (nonwoven) may be less than or equal to 5.0 in the MD and CD directions. The specific potential stress index is as described in the content related to the manufacturing method.

In one example, the thickness of the nonwoven fabric may be within the range of 0.20 to 0.60 mm. The specific thickness is the same as described in the content related to the manufacturing method.

In one example, the unit weight, that is, the basis weight, of the nonwoven fabric may be 70 to 140 g/m ² . The specific basis weight of the nonwoven fabric is the same as described in the content related to the manufacturing method.

In one example, the nonwoven fabric may include 80 to 92% by weight of the high melting point polyester yarn and 8 to 20% by weight of the low melting point polyester yarn. The weight ratio between specific ingredients is the same as described in the content related to the manufacturing method.

In one example, in the nonwoven fabric, the ratio (N ₁ /N ₂ ) of the number of high melting point polyester yarns (N ₁ ) (number of filaments) to the number of low melting point polyester yarns (N ₂ ) is 2.0 to 5.0. It may be a range. The specific number ratio is the same as described in the content related to the manufacturing method.

The fineness of the high melting point polyester yarn and low melting point polyester yarn included in the nonwoven fabric is the same as described in the content related to the manufacturing method.

The melting points of the polyesters included in the high melting point polyester yarn and the low melting point polyester yarn are the same as those described in the content related to the manufacturing method.

The types of polyester included in the high melting point polyester yarn and the low melting point polyester yarn are the same as described in the content related to the manufacturing method.

Other components of the non-woven fabric, such as components used to manufacture the non-woven fabric and their characteristics, are explained in the content related to the manufacturing method and are therefore omitted.

In another example related to this application, this application relates to a method of making a carpet. The method may include planting carpet yarn on one side of the nonwoven fabric manufactured according to the above-described method using a needle.

Specifically, the method:

A first step of producing a web by melt spinning a high-melting point polyester having a melting point (T _H ) and a low-melting point polyester having a melting point (T _L ) lower than the melting point (T _H );

a second step of joining the web;

a third step of imparting an emulsion to the combined web (eg, non-woven fabric);

A fourth step of applying heat to the nonwoven fabric to which the emulsion has been applied so that the potential stress index is 5.00 or less; and

A fifth step of planting carpet yarn on one side of the nonwoven fabric using a needle;

Includes. The carpet yarn may be, for example, BCF yarn.

In relation to the carpet manufacturing method, the description of the first to fourth steps is the same as described above.

The fifth step is a so-called tufting process, and can be performed using known methods and equipment. For example, the tufting may be made in a loop shape and at a certain gauge (for example, 1/10 gauge). In addition, the tufting process may be performed so that the carpet yarn has a predetermined fineness (eg, 500 to 1500 denier) and height (eg, 3.0 to 0.7 mm). Through the tufting process, the carpet yarns are planted so that they can be seen on one side of the nonwoven fabric.

In one example, the method of manufacturing the carpet may further include a sixth step of applying a resin coating liquid to the back side. The process that gives the carpet shape stability is called the back coating process, and in this case, the back side may mean, for example, the opposite side of the side where the carpet yarn is visible. In some cases, a glass mat may be used along with a resin component in the back coating process, and hot air may be applied to dry the coating solution.

The type of resin contained in the coating liquid for back coating is not particularly limited. For example, the coating liquid may contain a resin component such as PVC, PE, EVA, or SBR. The coating liquid described above or the back coating layer obtained therefrom may be formed of one or more layers.

In one example, the method may further include a seventh step of cutting the obtained carpet to a certain size after the resin coating liquid applied to the back is dried. After going through these steps, a tile carpet can be manufactured.

Curling, where the four corners are lifted, may occur in manufactured tile carpets. If the degree of curling is severe, tile carpet construction may not be possible, so it is required to reduce the degree of curling. Such attempts have continued in related technical fields. As described above, in this application, the curling problem of carpet can be efficiently managed and prevented by quantitatively confirming and evaluating the potential stress remaining in the nonwoven fabric during the nonwoven fabric manufacturing process.

In another example related to this application, this application relates to carpet. The carpet includes a nonwoven fabric having the characteristics described above, and yarns planted in the nonwoven fabric. The carpet may have an improved curling problem at the edges.

In one example, the carpet may be a tile carpet.

Other than that, the composition and manufacturing method of the carpet are the same as those described above, so they are omitted.

According to the present application, a nonwoven fabric, a carpet, and a method for manufacturing the same can be provided with excellent shape stability, such as improving the curling problem. In addition, the present application has the effect of providing a nonwoven fabric and a manufacturing method thereof that enable quantitative evaluation and prediction of dimensional stability.

Hereinafter, the operation and effects of the invention will be described in more detail through specific examples of the invention. However, this is presented as an example of the invention, and the scope of the invention is not limited by this in any way.

<Examples and Comparative Examples>

Example 1

PET raw material (first ingredient raw material) with an intrinsic viscosity (IV) of 0.645 and a melting temperature of 254°C; And Co-PET raw material (second component raw material) (Co-PET manufactured using adipic acid as a copolymerization monomer) with an intrinsic viscosity (IV) of 0.920 and a melting temperature of 171 ° C. was prepared. Then, filament fibers were manufactured by spinning the above raw materials using a spunbond manufacturing device at a spinning speed of 5,000 m/min and a spinning temperature of 270°C. At this time, the fineness of the first component PET was adjusted to 8.5 De', the fineness of the second component Co-PET was adjusted to 3.6 De', and the weight ratio (wt%) of the first component PET and the second component Co-PET ) was adjusted to 85:15. In addition, the ratio (N ₁ /N ₂ ) between the number of first filaments (N ₁ ) and the number of second filaments (N ₂ ) was adjusted to 2.3.

Spunbond nonwoven fabric was manufactured by laminating the spun filament fibers in a web form on a moving conveyor net, first bonding them at a calender temperature of 140°C, and secondarily bonding them at a HAT hot air temperature of 175°C. Next, the emulsion was coated on the nonwoven fabric so that the content of the emulsion was about 0.5 wt% based on 100 wt% of the total weight of the nonwoven fabric produced. The basis weight of the emulsion-coated nonwoven fabric is about 90 gsm, and the thickness is about 0.34 mm. After emulsion coating, tensile strength, tear strength, and potential stress index were measured as described below.

The manufactured nonwoven fabric (carpet foam paper) was placed in a separate cylindrical heat treatment device and re-heat treated at a temperature of 150°C for 20 seconds while moving at a speed of 30 m/min. After reheat treatment, the tensile strength, tear strength, shrinkage rate, and potential stress index described below were measured.

Then, tufting was performed on the non-woven fabric (carpet base paper) (1/10 gauge, carpet yarn (BCF) 1240 De’, pile yarn height 4.0 mm). Afterwards, a tile carpet was manufactured by coating 6.4 kg/m2 of PVC solution and glass mat on foam paper to which carpet yarn was tufted. For the final manufactured tile carpet, the curling values for the four corners of the tile carpet were measured (through Aachen evaluation) as described below.

Example 2

Nonwoven fabrics and carpets were manufactured through the same process as described in Example 1, except that re-heat treatment was performed for 60 seconds at a speed of 10 m/min.

Example 3

The melting point and intrinsic viscosity (IV) of Co-PET, which is the second component raw material, are 226 ℃ and 0.820, respectively, the spinning temperature of the second component raw material is 280 ℃, the calender temperature is 180 ℃, and the HAT hot air temperature is Nonwoven fabrics and carpets were manufactured through the same process as described in Example 1, except that the temperature was 205°C, and the reheat treatment was performed at a speed of 30 m/min for 20 seconds at 205°C.

Example 4

Nonwoven fabrics and carpets were manufactured through the same process as described in Example 3, except that re-heat treatment was performed for 60 seconds at a speed of 10 m/min.

Example 5

Nonwoven fabrics and carpets were manufactured through the same process as described in Example 4, except that the reheat treatment temperature was set to 175°C.

Comparative Example 1

Nonwoven fabrics and carpets were manufactured through the same process as described in Example 1, except that re-heat treatment was performed for 5 seconds at a speed of 120 m/min.

Comparative Example 2

Nonwoven fabrics and carpets were manufactured through the same process as described in Example 1, except that re-heat treatment was performed at 160°C.

Comparative Example 3

Nonwoven fabrics and carpets were manufactured through the same process as described in Example 1, except that re-heat treatment was performed at a speed of 4 m/min and a temperature of 150° C. for 150 seconds.

Comparative Example 4

Nonwoven fabrics and carpets were manufactured through the same process as described in Example 3, except that re-heat treatment was performed at a speed of 120 m/min and a temperature of 205° C. for 5 seconds.

Comparative Example 5

Nonwoven fabrics and carpets were manufactured through the same process as described in Example 3, except that re-heat treatment was performed at a temperature of 220°C.

Comparative Example 6

Nonwoven fabrics and carpets were manufactured through the same process as described in Example 3, except that re-heat treatment was performed at a speed of 4 m/min and a temperature of 205° C. for 150 seconds.

Comparative Example 7

Nonwoven fabrics and carpets were manufactured through the same process as described in Example 3, except that re-heat treatment was performed at a speed of 5 m/min and a temperature of 100° C. for 120 seconds.

Comparing the nonwoven fabric manufacturing process of Examples and Comparative Examples is as follows.

1 ingredient 2 ingredients Web binding conditions Potential stress index control conditions Intrinsic viscosity (IV)
/ Melting point (℃) Intrinsic viscosity (IV)
/ Melting point (℃) T ₁ (℃) T ₂ (℃) T ₃ (℃) Time(sec) Example 1 0.645 / 254 0.920 / 171 140 175 150 20 Example 2 0.645 / 254 0.920 / 171 140 175 150 60 Example 3 0.645 / 254 0.820 / 226 180 205 205 20 Example 4 0.645 / 254 0.820 / 226 180 205 205 60 Example 5 0.645 / 254 0.820 / 226 180 205 175 60 Comparative Example 1 0.645 / 254 0.920 / 171 140 175 150 5 Comparative Example 2 0.645 / 254 0.920 / 171 140 175 160 20 Comparative Example 3 0.645 / 254 0.920 / 171 140 175 150 150 Comparative Example 4 0.645 / 254 0.820 / 226 180 205 205 5 Comparative Example 5 0.645 / 254 0.820 / 226 180 205 220 20 Comparative Example 6 0.645 / 254 0.820 / 226 180 205 205 150 Comparative Example 7 0.645 / 254 0.820 / 226 180 205 100 120 T ₁ : first binding temperature
T ₂ : second bonding temperature
T ₃ : Temperature of heat applied to control potential stress index
Time: Time at which T ₃ is applied

<Method for evaluating physical properties>

The following physical properties were evaluated for the nonwoven fabrics and/or carpets prepared in Examples and Comparative Examples, and the results are shown in Tables 2 and 3.

1. Tensile strength (kgf/5cm)

Tensile strength was measured according to KS K 0521 (Cut Strip). Specifically, the spunbond nonwoven fabrics of Examples and Comparative Examples were manufactured into specimens of 20 cm The tensile strength for each was measured. These tensile strengths were measured before and after reheat treatment to measure the potential stress index.

2. Tear strength (kgf)

Tear strength was measured according to KS K 0536 (Single Tongue). Specifically, the spunbond nonwoven fabrics of Examples and Comparative Examples were manufactured into specimens measuring 7.6 cm The tearing strength for each was measured. This tearing strength was measured before and after reheat treatment to measure the potential stress index.

3. Potential stress index

The spunbond nonwoven fabrics of Examples and Comparative Examples were manufactured into specimens measuring 5.0 cm x 70 cm, and the potential stress was measured in accordance with DIN 53369 (Thermal shrinkage and shrinkage force). Specifically, according to DIN 53369, the thermal stress (cN) can be measured for 2 minutes in a 180 ℃ chamber after fixing the nonwoven fabric with a weight of 50 g. After the 2-minute time for measuring the thermal stress value, wait. The cooling stress (potential stress) was measured by exposing the nonwoven fabric for 1 minute. Then, the measured cooling stress (cN) was divided by the unit weight of the specimen (g/m ² ), and the potential stress index was obtained. The potential stress index is treated as a dimensionless constant.

These tensile strengths were measured before and after reheat treatment to measure the potential stress index.

4. Width shrinkage rate (%)

The rate of change before and after reheat treatment was expressed as shrinkage rate based on 3.8m, the width of a typical nonwoven fabric used as a carpet base paper. And, this was calculated for the nonwoven fabrics manufactured in Examples and Comparative Examples.

Width shrinkage (%)

= [(Width of nonwoven fabric before reheat treatment)-(Width of nonwoven fabric after reheat treatment)]/(Width of nonwoven fabric before reheat treatment) x 100

At this time, the width of the nonwoven fabric before reheat treatment is 3.8 mm.

5. Curling (mm)

Curling was measured according to DIN EN 986 (Aachen Test). Specifically, preheat a tile carpet (50 Preheat treatment was performed for 24 hours. Then, the curling height was measured after the preheat-treated tile carpet was left at room temperature for 48 hours. At this time, the curling is the average value of the curling height measured for each of the four corners.

division Before reheat treatment
Tensile strength (kgf/5cm) Before reheat treatment
Tear strength (kgf) Before reheat treatment
Potential stress index M.D. CD M.D. CD M.D. CD Example 1 21.5 21.1 9.4 9.6 6.41 6.10 Example 2 23.4 23.2 8.6 8.5 6.52 6.26 Example 3 22.5 21.9 7.4 7.0 8.52 8.43 Example 4 23.9 24.0 7.3 7.1 8.69 8.62 Example 5 25.1 24.7 7.0 6.9 8.88 8.85 Comparative Example 1 21.4 21.3 9.5 9.5 6.40 6.32 Comparative Example 2 23.1 23.2 8.4 8.6 6.68 6.59 Comparative Example 3 23.2 23.5 8.5 8.6 6.70 6.67 Comparative Example 4 22.8 22.2 7.5 7.1 8.65 8.53 Comparative Example 5 23.7 23.8 7.2 7.1 8.74 8.80 Comparative Example 6 25.0 24.8 6.4 6.4 9.10 9.08 Comparative Example 7 25.4 25.3 6.4 6.5 9.02 8.95

division After reheat treatment
Tensile strength (kgf/5cm) After reheat treatment
Tear strength (kgf) After reheat treatment
Potential stress index Width shrinkage rate
(%) Curling
(mm) M.D. CD M.D. CD M.D. CD Example 1 22.6 22.1 9.0 9.1 3.85 3.92 0.1 0.2 Example 2 23.9 24.0 7.8 8.0 3.52 3.26 0.4 0.1 Example 3 22.8 22.9 8.3 7.9 4.61 4.53 0.1 0.4 Example 4 24.0 24.4 7.8 7.4 4.31 4.38 0.4 0.3 Example 5 25.2 25.3 7.1 7.2 4.31 4.57 0.2 0.5 Comparative Example 1 22.3 20.4 8.4 8.5 5.40 5.52 0.0 0.7 Comparative Example 2 26.4 27.0 6.3 5.0 6.41 6.85 2.4 0.9 Comparative Example 3 27.5 26.9 5.1 5.7 6.99 6.57 2.3 1.5 Comparative Example 4 23.8 23.3 7.4 7.4 6.51 6.34 0.1 1.0 Comparative Example 5 29.0 28.8 5.7 5.4 11.10 12.45 3.1 4.3 Comparative Example 6 28.4 27.6 5.0 5.0 9.45 10.01 2.9 3.4 Comparative Example 7 26.5 26.7 6.3 6.6 9.00 8.64 0.0 3.8 *MD: machine direction
*CD: corss direction

Through Tables 2 and 3 above, when reheat treatment is performed under the same conditions as in the example and the potential stress index is adjusted to 5.0 or less, the average width shrinkage of the nonwoven fabric and the degree of curling of the carpet are simultaneously reduced compared to the comparative example. You can see that it can be done. That is, according to the present application, nonwoven fabrics and carpets with excellent shape stability can be provided.

Meanwhile, when comparing the degree of change in tensile strength and tear strength before and after reheat treatment by arithmetic averaging, it can be seen that the change in tensile strength and tear strength before and after reheat treatment is not significant when reheat treatment is performed according to the embodiment of the present application. This means that mechanical properties and shape stability can be secured simultaneously through re-heat treatment according to the present application.

Claims (20)

A first step of producing a web by melt spinning a high-melting point polyester having a melting point (T _H ) and a low-melting point polyester having a melting point (T _L ) lower than the melting point (T _H );
a second step of joining the web;
a third step of imparting an emulsion to the bonded web; and
It includes a fourth step of applying heat to the nonwoven fabric to which the emulsion has been applied so that the potential stress index is 5.00 or less,
A method of manufacturing a nonwoven fabric in which the fourth step is performed by applying heat for 10 to 130 seconds at a temperature (T ₃ ) that satisfies the equation 1 below (however, the potential stress index is calculated at 180°C for 5 minutes according to DIN 53369). The nonwoven fabric is exposed within 1 minute, the nonwoven fabric is cooled at room temperature for 1 minute, and the measured cooling stress (cN) is divided by the unit weight of the nonwoven fabric (g/m ² ), which is a dimensionless constant).
[Relational Expression 1]
20 ℃ ≤ Melting point of low-melting polyester (T _L ) - Temperature (T ₃ ) ≤ 60 ℃
delete According to claim 1,
A method of producing a nonwoven fabric, producing a web comprising 80 to 92% by weight of high melting point polyester yarn and 8 to 20% by weight of low melting point polyester yarn.
According to claim 3,
A method for producing a nonwoven fabric, which produces a web comprising the high melting point polyester yarn having a fineness of 7.0 to 10.0 denier, and the low melting point polyester yarn having a fineness of 2.0 to 5.0 denier.
According to claim 3 or 4,
The ratio (N ₁ /N ₂ ) between the number of high melting point polyester yarns ( _{N 1} ) (number of filaments) to the number of low melting point polyester yarns (N 2 ) is a non-woven fabric that produces a web in which the number is in the range of 2.0 to 5.0. Manufacturing method.
According to claim 3,
The melting point (T _H ) of the high melting point polyester is 250°C or higher, and the melting point (T _L ) of the low melting point polyester is 245°C or lower.
According to claim 1,
The high melting point and low melting point polyester is any one selected from polyethylene terephthalate, polybutylene terephthalate, and polynaphthalene terephthalate. Method for producing a nonwoven fabric.
According to claim 7,
The low melting point polyester is a polyester copolymerized with adipic acid, a polyester copolymerized with isophthalic acid, or a polyester copolymerized with adipic acid and isophthalic.
According to claim 1,
A method of manufacturing a nonwoven fabric (however, passing a web through a roll having a first heat bonding temperature (T ₁ ) and bonding the web by applying a second heat bonding temperature (T ₂ ) to the web that has passed through the roll , the second thermal bonding temperature (T ₂ ) is a temperature higher than the first thermal bonding temperature (T ₁ ).
According to clause 9,
The first heat bonding temperature (T ₁ ) is in the range of 120 to 190°C, and the second heat bonding temperature (T ₂ ) is in the range of 140 to 240°C.
According to claim 1,
The temperature (T ₃ ) satisfies the equation 2 below, a method of producing a nonwoven fabric:
[Relational Expression 2]
First heat bonding temperature (T ₁ ) ≤ temperature (T ₃ ) ≤ second heat bonding temperature (T ₂ )
According to claim 1,
A method of producing a nonwoven fabric, wherein an emulsion is applied to the combined web so that the content is 0.05% by weight or more out of 100% by weight of the total weight of the nonwoven fabric.
High melting point polyester yarn and low melting point polyester yarn fused to each other manufactured according to claim 1; and a nonwoven fabric containing an emulsion,
The nonwoven fabric is a nonwoven fabric with a potential stress index of 5.00 or less (however, the potential stress index is the cooling stress measured after exposing the nonwoven fabric to a temperature of 180°C for less than 5 minutes according to DIN 53369 and cooling the nonwoven fabric for 1 minute at room temperature. (cooling stress) (cN) divided by the unit weight of the nonwoven fabric (g/m ² ), which is a dimensionless constant).
According to claim 13,
A nonwoven fabric having a thickness ranging from 0.20 to 0.60 mm and a unit weight ranging from 70 to 140 g/m ² .
According to claim 13,
A nonwoven fabric comprising 80 to 92% by weight of the high melting point polyester yarn and 8 to 20% by weight of the low melting point polyester yarn.
According to claim 13,
A nonwoven fabric in which the ratio (N ₁ /N ₂ ) of the number of high melting point polyester yarns (N ₁ ) (number of filaments) to the number of low melting point polyester yarns (N ₂ ) is in the range of 2.0 to 5.0.
According to claim 13,
The high melting point polyester yarn has a fineness of 7.0 to 10.0 denier, and the low melting point polyester yarn has a fineness of 2.0 to 5.0 denier.
According to claim 13,
The melting point (T _H ) of the high melting point polyester is 250 ℃ or more, and the melting point (T _L ) of the low melting point polyester is 245 ℃ or less.
Planting carpet yarn on one side of the nonwoven fabric manufactured according to claim 1 using a needle;
A method of manufacturing a carpet comprising.
Non-woven fabric according to claim 13; and a carpet comprising yarns planted in the nonwoven fabric.