Nonwoven fabric, carpet, and method for producing the same

Abstract

The present invention relates to a nonwoven fabric, a carpet, and a method for producing the same. According to the present invention, it is possible to provide a nonwoven fabric and a carpet that have an improved curling problem and excellent shape stability, and a method for producing the same. Furthermore, the present invention is also possible to provide a nonwoven fabric and a method for producing the same that enable quantitative evaluation and prediction of shape stability.

Description

Technical Field

[0001] [Cross - reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2020 - 0187593 filed on December 30, 2020, and all the contents disclosed in the literature of the Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a non - woven fabric, a carpet, and a method for manufacturing the same. Specifically, the present invention relates to a spunbond non - woven fabric, a carpet, and a method for manufacturing the same.

Background Art

[0003] A carpet is manufactured through a tufting process in which carpet yarn (BCF yarn) is implanted into a non - woven fabric for bubble wrap. And the external forces (such as physical pressure or heat) that the non - woven fabric (bubble wrap) and the carpet receive in the manufacturing process are considerable.

[0004] For example, in the stage of manufacturing yarn in the non - woven fabric manufacturing process, external forces such as heat, tensile force, and cooling are applied, and high temperature and pressure are required to bond (for example, fix in web form) the non - woven fabric web. Also, in the tufting process, holes are generated in the non - woven fabric by needles and it is damaged, and heating and cooling are required in the back - coating process.

[0005] Such manufacturing processes impart potential stress to the non - woven fabric and the carpet, and reduce the form stability and mechanical properties of the non - woven fabric and the carpet.

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of the present invention is to provide a non - woven fabric and a method for manufacturing the same.

[0007] Another object of the present invention is to provide a non - woven fabric with improved form stability and a method for manufacturing the same.

[0008] Still another object of the present invention is to provide a nonwoven fabric having excellent mechanical properties and a method for producing the same.

[0009] Still another object of the present invention is to provide a nonwoven fabric for which evaluation and prediction regarding morphological stability can be quantitatively performed.

[0010] Still another object of the present invention is to provide a method for producing a nonwoven fabric that can quantitatively evaluate and predict the morphological stability of the nonwoven fabric so as to adjust and evaluate (or confirm) the potential stress index of the nonwoven fabric during the manufacturing process.

[0011] Still another object of the present invention is to provide a nonwoven fabric and a carpet including the same.

[0012] The above object and other objects of the present invention can all be solved by the present invention described in detail below.

Means for Solving the Problems

[0013] In an example according to the present invention, the present invention relates to a method for producing a nonwoven fabric. Specifically, the method relates to a method for producing a long fiber spunbond nonwoven fabric.

[0014] According to the present invention, the method includes a step of binding webs (for example, fixing the web form), applying an oil agent, and then applying heat to relieve potential stress. More specifically, the method A high melting point polyester having a melting point T H and a low melting point polyester having a melting point T H lower than the melting point T L are melt-spun to produce a web in a first step, a second step of binding the web, a third step of applying an oil agent to the bound web, A fourth step of applying heat so that the potential stress index of the nonwoven fabric to which the oil agent is applied is 5.00 or less, is included. The method can effectively reduce the potential stress remaining in the nonwoven fabric.

[0015] As a result of experimental confirmation, when the weight of the nonwoven fabric is low, the stress value tends to be relatively low, and when the nonwoven fabric has a high weight, the stress tends to be high. However, just because the nonwoven fabric shows a relatively low stress does not necessarily mean that the degree of curl generation is small. Therefore, considering both the weight (weighing) and the stress value that affect the morphological stability of the nonwoven fabric is significant for predicting the degree of curl generation of the carpet, which is the final product, and reducing the occurrence of curl in the manufacturing stage of the nonwoven fabric.

[0016] As a result of intensive research, the inventor has confirmed that when heat is applied to the nonwoven fabric to which the oil agent is applied so that the potential stress index is adjusted to 5.00 or less, it is possible to simultaneously ensure the mechanical properties (and uniformity) and morphological stability of the nonwoven fabric and the carpet manufactured therefrom, and thus completed the present invention.

[0017] The potential stress index is a value obtained by dividing the stress of the nonwoven fabric measured according to DIN 53369 by the unit weight (g / m 2 ) of the nonwoven fabric, as will be described in the experimental example below. Specifically, the potential stress index is obtained by exposing the nonwoven fabric at a temperature of 180 °C for within 5 minutes according to DIN 53369, cooling the nonwoven fabric to room temperature for about 1 minute, and then dividing the measured cooling stress (cN) by the unit weight (g / m 2 ) of the nonwoven fabric, and is treated as a dimensionless constant. In some cases, the stress (thermal stress) can be measured during the heat treatment of the nonwoven fabric. At this time, the exposure time of the nonwoven fabric to heat at 180 °C can be within 4 minutes, within 3 minutes, or within 2 minutes.

[0018] Thus, the method of the present invention includes a step of adjusting the potential stress index of the nonwoven fabric during the manufacturing process of the nonwoven fabric, thereby quantitatively evaluating and performing a process capable of improving the morphological stability of the nonwoven fabric in order to numerically evaluate (or confirm) the potential stress of the nonwoven fabric at this stage. Therefore, it is also possible to quantitatively predict and evaluate the morphological stability of the nonwoven fabric.

[0019] On the other hand, when these are affected by heat or temperature in relation to the articles, article characteristics, and process conditions for manufacturing the articles mentioned in this specification, unless otherwise specified, the heat or temperature may be normal temperature. At this time, "normal temperature" means the temperature in a state where it is not particularly cooled or heated, for example, a temperature within the range of 15 to 30°C.

[0020] Hereinafter, each step regarding the manufacturing method of the present invention will be described in detail.

[0021] The method has a melting point T H of a high melting point polyester, and a melting point T H lower than that, and includes a first step of melt-spinning a low melting point polyester having a melting point T L to produce a web.

[0022] The form of the web is not particularly limited. For example, the web can be in an isotropic or anisotropic form.

[0023] As an example, the method can produce a web containing 80 to 92% by weight of high melting point polyester filaments and 8 to 20% by weight of low melting point polyester filaments. At this time, the term "filament" can be used interchangeably with the term "filament".

[0024] Specifically, the lower limit of the content of the low-melting-point polyester yarn can be, 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, 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 content of the low-melting-point polyester yarn can be, 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% by weight or less, 15.5% by weight or less, 15.0% by weight or less, 14.5% by weight or less, 14.0% by weight or less, 13.5% by weight or less, 13.0% by weight or less, 12.5% by weight or less, 12.0% by weight or less, 11.5% by weight or less, 11.0% by weight or less, 10.5% by weight or less, or 10.0% by weight or less. When the content of the low-melting-point polyester serving as a hot melt adhesive is less than the above range, the hot melt effect is not sufficient. And when the content of the low-melting-point polyester exceeds the above range, while the degree of contact between fibers increases, the movement between fibers is restricted. As a result, when the needle penetrates the non-woven fabric (or bubble paper) in the tufting process, the degree of fiber damage becomes severe, and the tensile strength characteristics of the non-woven fabric deteriorate.

[0025] As an example, according to the above method, a web containing the high-melting-point polyester yarn with a fineness of 7.0 to 10.0 denier can be manufactured. When 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 breakage occurs in the tufting process, and the quality (e.g., uniformity) of the product deteriorates. Also, when the fineness of the high-melting-point polyester yarn exceeds the above range, it is difficult to manufacture a product with a uniform form due to insufficient cooling of the filament, and the height uniformity of the BCF yarn in the tufting process deteriorates.

[0026] As an example, according to the method, a web containing the low melting point polyester yarn with a fineness of 2.0 to 5.0 denier can be manufactured. When the fineness of the low melting point polyester yarn is less than the above range, the spinnability is poor. When it exceeds the above range, the quality of the product (for example, uniformity) deteriorates due to the bundle phenomenon in which filaments adhere to each other.

[0027] As an example, according to the method, a web containing the high melting point polyester yarn with a fineness of 7.0 to 10.0 denier and the low melting point polyester yarn with a fineness of 2.0 to 5.0 denier can be manufactured.

[0028] The fineness can be ensured by adjusting, for example, the spinning orifice diameter of the die used during spinning and the discharge amount during spinning.

[0029] As an example, according to the method, a web can be manufactured in which the ratio (N1 / N2) of the number N1 of the high melting point polyester yarns (number of filaments) to the number N2 of the low melting point polyester yarns is in the range of 2.0 to 5.0. Specifically, the lower limit of the ratio (N1 / N2) is, 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 thereof can be, for example, 4.5 or less, 4.0 or less, 3.5 or less, or 3.0 or less. When the ratio exceeds the above range, that is, when the high melting point component is excessively more than the low melting point component, it is difficult to provide sufficient strength due to insufficient bonding points between filaments. On the contrary, when the ratio is less than the above range, the bonding points increase and the degree of freedom between filaments (for example, movement between fibers) is restricted, which can cause damage to the fibers, for example, in the tufting process.

[0030] As an example, the melting point T of the high melting point polyester H can be 250°C or higher. Specifically, the melting point T of the high melting point polyester HThe lower limit can be, for example, 255 °C or higher, 260 °C or higher, 265 °C or higher, or 270 °C or higher. The melting point T of the high melting point polyester H The upper limit is not particularly limited, but can be, for example, 290 °C or lower, 285 °C or lower, 280 °C or lower, 275 °C or lower, 270 °C or lower, 265 °C or lower, or 260 °C or lower.

[0031] As an example, the melting point T of the low melting point polyester L can be less than 250 °C. Specifically, the upper limit of the melting point T of the low melting point polyester L can be, for example, 245 °C or lower, 240 °C or lower, 235 °C or lower, 230 °C or lower, 225 °C or lower, 220 °C or lower, 215 °C or lower, 210 °C or lower, 205 °C or lower, 200 °C or lower, 195 °C or lower, 180 °C or lower, 175 °C or lower, 170 °C or lower, 165 °C or lower, 160 °C or lower, or 155 °C or lower. And its lower limit can be, for example, 150 °C or higher, 155 °C or higher, 160 °C or higher, 165 °C or higher, 170 °C or higher, 175 °C or higher, 180 °C or higher, 185 °C or higher, 190 °C or higher, 195 °C or higher, 200 °C or higher, 205 °C or higher, 210 °C or higher, 215 °C or higher, 220 °C or higher, 225 °C or higher, or 230 °C or higher. When the melting point temperature of the low melting point polyester is less than the above range, the low melting point polyester component is likely to melt due to the heat applied during the process related to the non-woven fabric, resulting in easy breakage and heat shrinkage of the non-woven fabric (or bubble paper). Also, when the melting point temperature of the low melting point polyester exceeds the above range, the flexibility of the non-woven fabric decreases, and the elongation difference from the coating resin etc. used during the manufacture of the carpet becomes large, which causes a problem that the warping of the carpet edge becomes severe as the usage period of the carpet elapses.

[0032] As an example, the intrinsic viscosity (IV) of the high melting point polyester can be 0.640 or higher. For example, the lower limit of the intrinsic viscosity of the high melting point polyester can be, for example, 0.645 or higher or 0.650 or higher. The upper limit is not particularly limited, but can be, for example, 0.700 or lower.

[0033] As an example, the intrinsic viscosity (IV) of the low melting point polyester can be 0.725 or more. Specifically, the lower limit of the intrinsic viscosity of the low melting point polyester can be, for example, 0.750 or more, 0.800 or more, 0.850 or more, or 0.900 or more. Its upper limit is not particularly limited, but it can be, for example, 0.950 or less.

[0034] Regarding the high melting point and low melting point polyesters, the type of polyester is not particularly limited. For example, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polynaphthalene terephthalate can be used. Specifically, at least one or more of the polyesters listed above can be included in the web as a polyester component.

[0035] As an example, the low melting point polyester can be a copolyester. For example, the low melting point polyester can be a polyester copolymerized with adipic acid, a polyester copolymerized with isophthalic acid, or a polyester copolymerized with adipic acid and isophthalic acid. These copolymers can be produced by adding copolymer monomers such as adipic acid and isophthalic acid during the polymerization process.

[0036] As an example, the spinning can be carried out at a temperature higher than the melting point T of the high melting point polyester (for example, a temperature of 260 °C or higher). Such spinning can be carried out using a known apparatus. H More specifically, such spinning can be carried out at a temperature higher than the melting point T of the high melting point polyester (for example, a temperature of 260 °C or higher). Such spinning can be carried out using a known apparatus.

[0037] Although not particularly limited, the spinning can be carried out in a speed range of 3500 to 6000 m / min.

[0038] As an example, the two types of polyester are spun through respective holes from the same or different nozzles of a spinneret and simultaneously cooled, and as a result, solidified. The cooling method is not particularly limited, and for example, it can be carried out using cooling air at an appropriate temperature or atmospheric temperature (room temperature).

[0039] As an example, the filament can be drawn at a predetermined draw ratio. For example, the cooled filament can be drawn at a predetermined spinning speed, and each filament is drawn at regular intervals.

[0040] The method includes a second step of bonding the webs. Specifically, the second step may be a step of applying heat to the webs to bond the webs. By this step, the webs are bonded, and a so-called non-woven fabric with a fixed form is obtained.

[0041] Applying heat to the webs to bond the webs can be carried out by a known method. For example, a roll (e.g., a calendar roll or an embossing roll) or a roller and hot air (HAT: hot air through) are used. At this time, it can also be carried out together with pressurization. The form of the roll, the method of applying hot air, and the means or method for maintaining (or providing heat to the webs) each heat bonding temperature can be appropriately selected by those skilled in the art from known techniques.

[0042] As an example, the method can pass the web through a roll having a first heat bonding temperature T1 and apply a second heat bonding temperature T2 to the web that has passed through the roll to bond the web. That is, specifically, the second step can be carried out in such a way that the web is passed through a roll maintaining the first heat bonding temperature T1, and the second heat bonding temperature T2 by hot air is applied to the web that has passed through the roll. At this time, the first heat bonding temperature T1 can be a temperature equal to or lower than the second heat bonding temperature T2. Although not particularly limited, the web can pass between two rolls, and in this case, pressurization on the web is carried out between the two rolls.

[0043] As an example, the second thermal bonding temperature T2 by the hot air may be the same as or higher than the first thermal bonding temperature T1.

[0044] As an example, the first thermal bonding temperature T1 can be in the range of 120 to 190 °C. Appropriate form stability of the non-woven fabric can be imparted at this temperature.

[0045] As an example, the second thermal bonding temperature T2 by the hot air can be in the range of 140 to 240 °C. Appropriate form stability of the non-woven fabric can be imparted at this temperature.

[0046] As an example, the second thermal bonding temperature T2 may be higher than the first thermal bonding temperature T1. Specifically, the temperature difference between the first thermal bonding temperature T1 and the second thermal bonding temperature T2 can be in the range of 20 to 60 °C (T2 > T1). Appropriate form stability of the non-woven fabric can be imparted at this temperature.

[0047] The method includes a third step of applying (coating) an oil agent to the bonded web (e.g., non-woven fabric).

[0048] The oil agent can form a film on the surface of the web (non-woven fabric) or the filaments forming the same. Since the film can reduce the friction between the needle and the non-woven fabric generated during the penetration of the needle in the subsequent tufting process, damage to the web or the fibers forming the same can be prevented. Also, since heat generation due to friction is reduced through the oil agent film, the life of the needle can be extended.

[0049] As an example, the oil agent can be applied (coated) to the bonded web (or the filaments forming the same) such that the content is 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 serving as the standard for the oil agent content can be, for example, the weight of the nonwoven fabric to which the oil agent is applied in the third step, the weight of the nonwoven fabric that has undergone the web bonding step, or the weight of the nonwoven fabric manufactured by performing the fourth step described below. Specifically, the lower limit of the content of the oil agent can be, 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 oil agent can be, 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 or less, or 1.0% by weight or less. When the content of the oil agent is less than the above range, the content of the oil agent is insufficient and the oil agent cannot uniformly penetrate into the filaments forming the nonwoven fabric, and it is difficult to form a sufficient oil agent film. As a result, the filaments may be damaged during the tufting process. Also, when using a small content of the oil agent, the tufting property deteriorates and the BCF yarn will come out. And when the content of the oil agent exceeds the above range, the slipperiness increases and it is not suitable for the winding process, and it is difficult to control the tension. Furthermore, the excessive oil agent will adhere to the needle bar used in the tufting process, and foreign matters such as dust will remain on the oil agent adhered to the needle bar, which may prevent the carpet yarn from being planted at uniform intervals in the tufting process.

[0050] The types of oil agents that can be used are not particularly limited. For example, as the oil agent, a silicone-based oil agent or an ester-based oil agent can be used.

[0051] The method includes a fourth step of applying heat so that the potential stress index of the combined web or the nonwoven fabric applied with the sizing agent is 5.00 or less. The inventor experimentally confirmed in an experimental example described later that when the potential stress index exceeds 5.00, the degree of curl of the product becomes remarkable and the shape stability is not good. The potential stress index is obtained by exposing the nonwoven fabric at a temperature of 180° C. within 5 minutes according to DIN 53369, and then cooling the nonwoven fabric at room temperature for about 1 minute, and then dividing the measured cooling stress (cN) by the unit weight (g / m 2 ) of the nonwoven fabric for calculation.

[0052] As an example, the potential stress index of the combined web (nonwoven fabric) can be 5.00 or less in the MD (machine direction or mechanical, machine direction).

[0053] As an example, the potential stress index of the combined web (nonwoven fabric) can be 5.00 or less in the CD (cross direction, perpendicular direction).

[0054] As an example, the potential stress index of the combined web (nonwoven fabric) can be 5.0 or less in both the MD and CD.

[0055] Specifically, in the MD and / or CD, the upper limit of the potential stress index can be, 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. And the lower limit of the potential stress index can be, for example, 1.5 or more, 2.0 or more, 2.5 or more, 3.0 or more, or 3.5 or more.

[0056] As an example, the step of applying heat to relax (potential) stress can be performed at a predetermined temperature T3. Specifically, the step of applying heat to relax stress can be performed at a temperature T3 that satisfies the following relational expression 1.

[0057] [Relational Expression 1] 20° C. ≤ melting point T of low-melting polyesterL - The temperature T3 ≤ 60°C

[0058] That is, the melting point T of the low melting point polyester L is greater than the temperature T3, and the difference between the melting point T of the low melting point polyester L and the temperature T3 can be in the range of 20 to 60°C.

[0059] When the fourth stage is performed while applying heat at the temperature T3 that satisfies the relational expression 1, not only is the coated oil agent dried, but also the potential stress applied to the nonwoven fabric (or web) in the process of manufacturing the nonwoven fabric (for example, the thermal bonding stage for bonding the web, etc.) is effectively reduced. Thereby, the morphological instability of the product (for example, curl or edge warping) caused by the potential stress can be improved.

[0060] Specifically, the lower limit of the temperature difference (ΔT = T L - T3) is, for example, 25°C or higher, 30°C or higher, 35°C or higher, 40°C or higher, 45°C or higher, 50°C or higher, or 55°C or higher, and the upper limit thereof can be, for example, 55°C or lower, 50°C or lower, 45°C or lower, 40°C or lower, 35°C or lower, 30°C or lower, or 25°C or lower. When the temperature difference (ΔT = T L - T3) is less than the above range, the stiffness of the nonwoven fabric increases, the tufting performance decreases, the width shrinkage of the nonwoven fabric increases, the initial physical property deformation of the nonwoven fabric becomes severe, and it is difficult to use the nonwoven fabric as a tile carpet bubble paper. In particular, when conditions less than the temperature difference (ΔT = T L - T3) are given, the tear strength of the nonwoven fabric significantly decreases, and there is a problem that the tile carpet bubble paper tears after tufting. Conversely, when the temperature difference (ΔT = T L - T3) exceeds the above range, it is difficult to effectively reduce the potential stress.

[0061] The method of applying heat at the temperature T3 that satisfies the relational expression 1 is not particularly limited. For example, known means and methods such as using a cylinder dryer or adding hot air can be considered to provide the temperature T3 that satisfies the relational expression 1.

[0062] As an example, the temperature T3 at which the step of applying heat to relax stress is performed can satisfy the following relational expression 2. Considering all the steps in which the nonwoven fabric is manufactured, it is advantageous for relaxing the potential stress that the temperature T3 satisfies the relational expression 2.

[0063] [Relational Expression 2] The first thermal bonding temperature T1 ≤ temperature T3 ≤ the second thermal bonding temperature T2

[0064] As an example, the step of applying heat to relax stress can be performed at the temperature T3 for 10 to 130 seconds. For example, the time for performing the step of applying heat to relax stress at the temperature T3 can be 20 seconds or more, 30 seconds or more, 40 seconds or more, 50 seconds or more, 60 seconds or more, 70 seconds or more, 80 seconds or more, 90 seconds or more, 100 seconds or more, 110 seconds or more, or 120 seconds or more. And the upper limit can 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 will not relax sufficiently, so the effect of reheat treatment cannot be obtained sufficiently. Also, if the time exceeds the above range, not only will the physical properties of the nonwoven fabric or the bubble paper to be manufactured from it be deformed, but the production equipment will become excessively large, the productivity will decrease, and the manufacturing cost will increase.

[0065] As an example, the thickness of the nonwoven fabric manufactured by the above method can be in the range of 0.20 to 0.60 mm. Specifically, the lower limit of the thickness of the nonwoven fabric can 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 can be, for example, 0.55 mm or less, 0.50 mm or less, 0.45 mm or less, or 0.40 mm or less.

[0066] As an example, the unit weight, that is, the basis weight of the nonwoven fabric manufactured by the above method can be 70 to 140 g / m 2 and can be. Specifically, the lower limit of the basis weight of the bonded web can be, for example, 75 g / m 2 or more, 80 g / m 285 g / m or more 2 90 g / m or more 2 95 g / m or more 2 100 g / m or more 2 105 g / m or more 2 and the upper limit thereof is, for example, 135 g / m or less 2 130 g / m or less 2 125 g / m or less 2 120 g / m or less 2 115 g / m or less 2 110 g / m or less 2 105 g / m or less 2 100 g / m or less 2 95 g / m or less 2 90 g / m or less 2 It may be less. When the above range is satisfied, an appropriate level of lightness and mechanical properties can be ensured.

[0067] As an example, the nonwoven fabric produced by 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 Or 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

[0068] In another example, the present invention relates to a nonwoven fabric. The nonwoven fabric can be provided by the above-described production method.

[0069] The nonwoven fabric includes high-melting-point polyester yarns and low-melting-point polyester yarns fused to each other; and an oil agent, and can satisfy a latent stress index of 5.00 or less. Specifically, the high-melting-point polyester yarns and the low-melting-point polyester yarns fused to each other form a nonwoven fabric (or web), and the oil agent can be coated on each polyester yarn or the nonwoven fabric (or web) to form a film. And the latent stress index in MD and / or CD of the nonwoven fabric can be, for example, 5.0 or less. The specific latent stress index is as described in the content related to the production method. ​

[0070] As an example, the potential stress index of the combined web (non-woven fabric) can be 5.0 or less in both the MD and CD directions. The specific potential stress index is as described in the content regarding the manufacturing method.

[0071] As an example, the thickness of the non-woven fabric can be in the range of 0.20 to 0.60 mm. The specific thickness is as described in the content regarding the manufacturing method.

[0072] As an example, the unit weight of the non-woven fabric, that is, the basis weight, can be 70 to 140 g / m 2 It can be. The specific basis weight of the non-woven fabric is as described in the content regarding the manufacturing method.

[0073] As an example, the non-woven fabric may contain 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 specific weight ratio between the components is as described in the content regarding the manufacturing method.

[0074] As an example, in the non-woven fabric, the ratio (N1 / N2) of the number N1 of the high melting point polyester yarns to the number N2 of the low melting point polyester yarns (the number of filaments) can be in the range of 2.0 to 5.0. The specific number ratio is as described in the content regarding the manufacturing method.

[0075] The fineness of the high melting point polyester yarn and the low melting point polyester yarn contained in the non-woven fabric is as described in the content regarding the manufacturing method.

[0076] The melting points of the polyester contained in the high melting point polyester yarn and the low melting point polyester yarn are as described in the content regarding the manufacturing method.

[0077] The types of polyester contained in the high melting point polyester yarn and the low melting point polyester yarn are as described in the content regarding the manufacturing method.

[0078] Descriptions of other components included in the nonwoven fabric, such as the components used in the manufacture of the nonwoven fabric and their properties, are omitted because they have been described in the content related to the manufacturing method.

[0079] In yet another example, the present invention relates to a method for manufacturing a carpet. The method can include a step of implanting carpet raw yarn on one surface of a nonwoven fabric manufactured by the method described above using a needle.

[0080] Specifically, the method includes: A high melting point polyester having a melting point T H and a low melting point polyester having a melting point lower than the melting point T H are melt-spun to produce a web in a first step; L a second step of bonding the web; a third step of applying an oil agent to the bonded web (e.g., nonwoven fabric); a fourth step of applying heat so that the potential stress index of the nonwoven fabric to which the oil agent is applied becomes 5.00 or less; and a fifth step of implanting carpet raw yarn on one surface of the nonwoven fabric using a needle. The carpet raw yarn can be, for example, a BCF yarn. Regarding the manufacturing method of the carpet, the descriptions of the first to fourth steps and the like are as described above.

[0081]

[0082] The fifth step is a step called a so-called tufting process and can be performed using known methods and apparatuses. For example, the tufting is in the form of a loop with a predetermined gauge (e.g., 1 / 10 gauge). And the tufting process is performed such that the carpet raw yarn has a predetermined fineness (e.g., 500 to 1500 denier) and height (e.g., 3.0 to 0.7 mm). By the tufting process, the carpet raw yarn is implanted on one surface of the nonwoven fabric so as to be visible.

[0083] ​As an example, the method for manufacturing the carpet may further include a sixth step of applying a resin coating liquid to the back surface. This step of imparting morphological stability to the carpet is called a so-called back coating process. At this time, the back surface means, for example, the opposite surface of the surface where the carpet raw yarn is visible. In some cases, a glass mat can be used together with the resin component in the back coating process, and hot air can be applied to dry the coating liquid.

[0084] 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. Such a coating liquid or the back coating layer obtained therefrom may be formed of one or more layers.

[0085] As an example, the method may further include a seventh step of cutting the obtained carpet into a certain size after the resin coating liquid applied to the back surface is dried. After this step, a tile carpet can be manufactured.

[0086] Curling may occur where the four corners of the manufactured tile carpet curl upwards. If the degree of curling is severe, it may be impossible to install the tile carpet, so it is required to reduce the degree of curling. Such attempts have continued in the related technical field. As described above, in the present invention, by quantitatively confirming and evaluating the potential stress remaining in the non-woven fabric during the manufacturing process of the non-woven fabric, the problem of curling of the carpet can be efficiently managed and prevented.

[0087] In yet another example, the present invention relates to a carpet. The carpet includes the non-woven fabric having the above-described characteristics and the raw yarn planted on the non-woven fabric. The carpet may have an improved problem of curling where the corners curl upwards.

[0088] As an example, the carpet can be a tile carpet.

[0089] In addition, since the configuration of the carpet and the manufacturing method thereof are as described above, they will be omitted.

Advantages of the Invention

[0090] According to the present invention, it is possible to provide a non-woven fabric, a carpet, and a manufacturing method thereof, which have improved curl problems and excellent morphological stability. In addition, the present invention can provide a non-woven fabric and a manufacturing method thereof, in which evaluation and prediction regarding morphological stability can be quantitatively performed.

Modes for Carrying Out the Invention

[0091] Hereinafter, the actions and effects of the present invention will be described in more detail according to specific embodiments of the present invention. However, such embodiments are merely presented as examples of the present invention, and the scope of rights of the present invention is not limited thereby.

[0092] <Examples and Comparative Examples> Example 1 A PET raw material (first component raw material) having an intrinsic viscosity (IV) of 0.645 and a melting temperature of 254°C; and a Co-PET raw material (second component raw material) having an intrinsic viscosity (IV) of 0.920 and a melting temperature of 171°C (Co-PET manufactured using adipic acid as a comonomer) were prepared. Then, using a spunbond manufacturing apparatus, the raw materials were each spun under the conditions of a spinning speed of 5,000 m / min and a spinning temperature of 270°C to produce filament fibers. 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 to the second component Co-PET was adjusted to 85:15. Also, the ratio (N1 / N2) of the number of first filaments N1 to the number of second filaments N2 was adjusted to 2.3.

[0093] After laminating the filament fibers spun onto a moving conveyor net in web form, they were first bonded at a calendar temperature of 140°C and then secondarily bonded at a HAT hot air temperature of 175°C to produce a spunbond nonwoven fabric. Next, the nonwoven fabric was coated with an oil agent so that the content of the oil agent was about 0.5 wt% based on the total weight of the produced nonwoven fabric of 100% by weight. The weighed nonwoven fabric coated with the oil agent was about 90 gsm and the thickness was about 0.34 mm. After coating with the oil agent, the tensile strength, tear strength, and potential stress index described below were measured.

[0094] The produced nonwoven fabric (carpet bubble paper) was put into a separate cylindrical heat treatment device and reheated at a temperature of 150°C for 20 seconds while moving at a speed of 30 m / min. After the reheat treatment, the tensile strength, tear strength, shrinkage rate, and potential stress index described below were measured.

[0095] Then, tufting was performed on the nonwoven fabric (carpet bubble paper) (1 / 10 gauge, carpet raw yarn (BCF) 1240 De’, pile raw yarn height 4.0 mm). Thereafter, PVC sizing solution and a glass mat were coated on the bubble paper tufted with the carpet raw yarn at 6.4 kg / m 2 only to produce a tile carpet. For the finally produced tile carpet, as described below, (after passing through the Aachen evaluation), the curl values for the four corners of the tile carpet were measured.

[0096] Example 2 Nonwoven fabrics and carpets were produced through the same process as in Example 1, except that the reheat treatment was performed at a speed of 10 m / min for 60 seconds.

[0097] Example 3 The melting point and intrinsic viscosity (IV) of Co-PET, which is the second component raw material, are 226°C and 0.820 respectively. The spinning temperature of the second component raw material is 280°C, the calendar temperature is 180°C, the HAT hot air temperature is 205°C. Except that the reheat treatment was carried out at a temperature of 205°C for 20 seconds at a speed of 30 m / min, non-woven fabrics and carpets were manufactured through the same process as in Example 1.

[0098] Example 4 Except that the reheat treatment was carried out at a speed of 10 m / min for 60 seconds, non-woven fabrics and carpets were manufactured through the same process as in Example 3.

[0099] Example 5 Except that the reheat treatment temperature was set at 175°C, non-woven fabrics and carpets were manufactured through the same process as in Example 4.

[0100] Comparative Example 1 Except that the reheat treatment was carried out at a speed of 120 m / min for 5 seconds, non-woven fabrics and carpets were manufactured through the same process as in Example 1.

[0101] Comparative Example 2 Except that the reheat treatment was carried out at 160°C, non-woven fabrics and carpets were manufactured through the same process as in Example 1.

[0102] Comparative Example 3 Except that the reheat treatment was carried out at a speed of 4 m / min at a temperature of 150°C for 150 seconds, non-woven fabrics and carpets were manufactured through the same process as in Example 1.

[0103] Comparative Example 4 Except that the reheat treatment was carried out at a speed of 120 m / min at a temperature of 205°C for 5 seconds, non-woven fabrics and carpets were manufactured through the same process as in Example 3.

[0104] Comparative Example 5 Except that the reheat treatment was carried out at a temperature of 220°C, non-woven fabrics and carpets were manufactured through the same process as in Example 3.

[0105] Comparative Example 6 A nonwoven fabric and a carpet were produced through the same process as in Example 3, except that the post-heat treatment was performed at a speed of 4 m / min at a temperature of 205°C for 150 seconds.

[0106] Comparative Example 7 A nonwoven fabric and a carpet were produced through the same process as in Example 3, except that the post-heat treatment was performed at a speed of 5 m / min at a temperature of 100°C for 120 seconds.

[0107] Comparing the manufacturing processes of the nonwoven fabrics of the examples and comparative examples is as follows.

[0108]

Table 1

[0109] <Physical Property Evaluation Method> The following physical properties of the nonwoven fabrics and / or carpets produced in the examples and comparative examples were evaluated, and the results are shown in Tables 2 and 3.

[0110] 1. Tensile strength (kgf / 5 cm) The tensile strength was measured according to KS K 0521 (Cut Strip). Specifically, the spunbond nonwoven fabrics of the examples and comparative examples were made into test pieces with a size of 20 cm × 5 cm, and the tensile strength in the MD and CD directions was measured using a universal tensile testing machine (Instron) while applying a tensile speed of 200 mm / min to the test pieces. Such tensile strength was measured before and after the post-heat treatment for the measurement of the potential stress index.

[0111] 2. Tear strength (kgf) The tearing strength was measured using KS K 0536 (Single Tongue). Specifically, the spunbond nonwovens of the examples and comparative examples were produced into test pieces with a size of 7.6 cm × 20 cm, and the tearing strength in the MD and CD directions was measured using a universal tensile testing apparatus (Instron) while applying a tensile speed of 300 mm / min to the test pieces. Such tearing strength was measured before and after the reheat treatment for the measurement of the potential stress index respectively.

[0112] 3. Potential stress index The spunbond nonwovens of the examples and comparative examples were produced into test pieces with a size of 5.0 cm × 70 cm, and the potential stress was measured according to DIN 53369 (Thermal shrinkage and shrinkage force). Specifically, according to DIN 53369, after fixing the nonwoven fabric with a load of 50 g, the thermal stress (cN) can be measured in a chamber at 180 °C for 2 minutes. However, after the time of 2 minutes during which the thermal stress value is measured has elapsed, the nonwoven fabric was exposed to the atmosphere for 1 minute to measure the cooling stress (potential stress). Then, the measured cooling stress (cN) was divided by the unit weight (g / m 2 ) of the test piece to obtain the potential stress index. The potential stress index is treated as a dimensionless constant.

[0113] Such tensile strength was measured before and after the reheat treatment for the measurement of the potential stress index respectively.

[0114] 4. Width shrinkage rate (%) Based on 3.8 m, which is the width of a general nonwoven fabric used as carpet bubble wrap, the change rate before and after the reheat treatment was indicated by the shrinkage rate. And this was calculated for the nonwovens produced in the examples and comparative examples.

[0115] Width shrinkage rate (%) = [(width of the nonwoven fabric before the reheat treatment) - (width of the nonwoven fabric after the reheat treatment)] / (width of the nonwoven fabric before the reheat treatment) × 100 At this time, the width of the nonwoven fabric before the reheat treatment is 3.8 mm.

[0116] 5. Curling (mm) The curling was measured according to DIN EN986 (Aachen Test). Specifically, a tile carpet (50×50 cm) was preheated in an oven at 60°C for about 30 minutes, immersed in water containing 1 wt% surfactant for about 30 minutes after being preheated, and then subjected to a heat treatment at 60°C for 24 hours. After the heat-treated tile carpet was left at room temperature for 48 hours, the curling height was measured. At this time, the curling was the average value of the curling heights measured for each of the four corners.

[0117] [Table 2]

[0118] [Table 3]

[0119] From Table 2 and Table 3 above, it was found that when reheating was performed under the conditions of the examples and the potential stress index was adjusted to 5.0 or less, the average width shrinkage rate of the non-woven fabric and the degree of curling of the carpet could be simultaneously reduced compared to the comparative examples. That is, according to the present invention, a non-woven fabric and a carpet excellent in morphological stability can be provided.

[0120] On the other hand, when the changes in tensile strength and tear strength before and after the reheating treatment were averaged arithmetically and compared, it was found that when the reheating treatment according to this example was performed, the changes in tensile strength and tear strength before and after the reheating treatment were not large. This means that the mechanical properties and morphological stability can be ensured simultaneously by the reheating treatment according to the present invention.

Claims

1. Melting point T Ｈ A high melting point polyester having, and the melting point T Ｈ A lower melting point T Ｌ A first step of producing a web by melt-spinning a low melting point polyester having each, respectively a second step of joining the webs; a third step of applying an oil agent to the joined web; a fourth step of applying heat so that the potential stress index of the nonwoven fabric to which the oil agent is applied becomes 5.00 or less, wherein the fourth step is represented by the following relational expression 1: [Relational Expression 1] 20°C ≤ melting point T of the low melting point polyester Ｌ - temperature T ３ ≤ 60°C Temperature T satisfying ３ heat is applied for 10 to 130 seconds at The melting point T of the high melting point polyester Ｈ is 250°C or higher, and the melting point T of the low melting point polyester Ｌ is 245°C or lower. A method for manufacturing a nonwoven fabric (wherein the potential stress index is measured by exposing the nonwoven fabric at a temperature of 180°C for within 5 minutes according to DIN 53369, cooling the nonwoven fabric to room temperature for about 1 minute, and then dividing the measured cooling stress (cN) by the unit weight (g / m ２ ) of the nonwoven fabric, which is a dimensionless constant).

2. The method for manufacturing a nonwoven fabric according to claim 1, wherein a web containing 80 to 92% by weight of a high melting point polyester yarn and 8 to 20% by weight of a low melting point polyester yarn is manufactured.

3. The method for manufacturing a nonwoven fabric according to claim 2, wherein a web containing 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 is manufactured.

4. The number N of the low melting point polyester filaments ２ to the number N of the high melting point polyester filaments １ (the number of filaments), the ratio (N １ / N ２ ) is in the range of 2.0 to 5.0, and a web is produced. The method for producing a nonwoven fabric according to claim 2 or 3

5. The method for manufacturing a nonwoven fabric according to claim 1, wherein the high melting point and low melting point polyesters are at least one selected from polyethylene terephthalate, polybutylene terephthalate, and polynaphthalene terephthalate.

6. The method for manufacturing a nonwoven fabric according to claim 5, wherein the low melting point polyester is a polyester in which one or more of adipic acid and isophthalic acid are copolymerized.

7. The first thermo-bonding temperature T １ Pass a web through a roll having the temperature, and apply a second thermo-bonding temperature T ２ to the web that has passed through the roll to bond the web. The method for manufacturing a nonwoven fabric according to claim 1 (however, the second thermo-bonding temperature T ２ is a temperature equal to or higher than the first thermo-bonding temperature T １ ).

8. The first thermal bonding temperature T １ is in the range of 120 to 190 °C, and the second thermal bonding temperature T ２ is in the range of 140 to 240 °C. The method for manufacturing a nonwoven fabric according to claim 7.

9. The temperature T ３ The method for manufacturing a nonwoven fabric according to claim 1, which satisfies the following relational expression 2: [Relational Expression 2] First thermal bonding temperature T １ ≤ temperature T ３ ≤ second thermal bonding temperature T ２

10. The method for manufacturing a nonwoven fabric according to claim 1, wherein an oil agent is applied to the joined web so as to have a content of 0.05% by weight or more based on 100% by weight of the total weight of the nonwoven fabric.

11. A nonwoven fabric comprising high melting point polyester yarns and low melting point polyester yarns fused to each other; and an oil agent, The number N of the low melting point polyester filaments ２ to the number N of the high melting point polyester filaments １ (the number of filaments) ratio (N １ / N ２ ) is in the range of 2.0 to 5.0, wherein the nonwoven fabric is provided with an oil agent and satisfies the following relational expression 1: [Relational Expression 1] 20°C ≤ melting point T of the low melting point polyester Ｌ - temperature T ３ ≤ 60°C Temperature T satisfying ３ The nonwoven fabric, which has been heated for 10 to 130 seconds at ３ and has a potential stress index of 5.00 or less (wherein the potential stress index is determined by exposing the nonwoven fabric at a temperature of 180 °C within 5 minutes according to DIN 53369, cooling the nonwoven fabric to room temperature for about 1 minute, and then dividing the measured cooling stress (cN) by the unit weight of the nonwoven fabric (g / m ２ ), which is a dimensionless constant).

12. The thickness is in the range of 0.20 to 0.60 mm, and the basis weight is in the range of 70 to 140 g / m ２ of the nonwoven fabric according to claim 11.

13. The nonwoven fabric according to claim 11, 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.

14. The nonwoven fabric according to claim 11, wherein 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.

15. The melting point T of the high melting point polyester Ｈ is 250°C or higher, and the melting point T of the low melting point polyester Ｌ is 245°C or lower. The nonwoven fabric according to claim 11.

16. A method for manufacturing a carpet, comprising a step of implanting carpet raw yarns on one surface of a nonwoven fabric manufactured by the method according to claim 1 using needles.

17. A carpet comprising the nonwoven fabric according to claim 11 and the filaments planted on the nonwoven fabric.

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