Punch carpet and method for manufacturing punch carpet

Abstract

This invention provides a punch carpet that is biodegradable and can be manufactured more easily, as well as a method for manufacturing the punch carpet. [Solution] The punch carpet has a single-layer structure in the nonwoven fabric region. The nonwoven fabric comprises a plurality of entangled rayon fibers 11 and polylactic acid fibers 12, and a binder 13. The binder 13 fixes the rayon fibers 11 and polylactic acid fibers 12 and is made of polylactic acid. The rayon fibers 11 and polylactic acid fibers 12 are non-melting at the melting point of the polylactic acid that constitutes the binder 13.

Description

[Technical Field]

[0001] The present invention relates to punch carpet and a method for manufacturing punch carpet. [Background technology]

[0002] Punch carpets, which are obtained by entangling fibers by punching with a needle, are known, and those that are biodegradable have also been proposed. For example, Patent Document 1 discloses an interior sheet having a multilayer structure and a fibrous surface formed by needle punching, and this interior sheet comprises a first layer, a second layer and a base material. The first layer is a needle-punched nonwoven fabric consisting of biodegradable aliphatic polyester fibers and first heat-fusible fibers that have a lower melting point than aliphatic polyester fibers and are biodegradable, with the mixing ratio of the first heat-fusible fibers being in the range of 5 to 50% by mass. The second layer is arranged above or below the first layer and is a needle-punched nonwoven fabric consisting of biodegradable flame-retardant fibers and second heat-fusible fibers that have a lower melting point than aliphatic polyester fibers and are biodegradable, with the mixing ratio of the second heat-fusible fibers being in the range of 5 to 50% by mass. Aliphatic polyester fibers are heat-fused together with a first heat-fusible fiber, and flame-retardant fibers are heat-fused together with the second heat-fusible fiber. The base material is provided between the first and second layers and consists of a woven or nonwoven fabric of a biodegradable polymer material. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2005-344237 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, the interior sheet disclosed in Patent Document 1 comprises two types of needle-punched nonwoven fabrics and a base material made of woven or nonwoven fabric between them, and is not easy to manufacture. A punch carpet that can be manufactured more easily and is biodegradable is desired.

[0005] Therefore, the present invention aims to provide a punch carpet that is biodegradable and can be manufactured more easily, and a method for manufacturing a punch carpet. [Means for solving the problem]

[0006] The punch carpet of the present invention is a punch carpet in which the nonwoven fabric region, composed of a nonwoven fabric, has a single-layer structure. The nonwoven fabric comprises a plurality of entangled biodegradable fibers and a binder, the binder which fixes the biodegradable fibers and is formed of polylactic acid. The biodegradable fibers are non-meltable at the melting point of the polylactic acid that forms the binder.

[0007] Thickness: Tmm, Basis Weight: Wg / m 2 In this case, it is preferable that the W / T ratio is at least 125.

[0008] The binder is preferably at least 10% by mass.

[0009] The biodegradable fiber is preferably a regenerated fiber, and the regenerated fiber is preferably a rayon fiber.

[0010] The method for manufacturing a punched carpet according to the present invention is a method for manufacturing a punched carpet in which a non-woven fabric region composed of a non-woven fabric has a single-layer structure, and includes a laminating step, a punching step, a heating step, and a cooling step. The laminating step laminates a web formed of a mixed fiber of a plurality of biodegradable fibers and a plurality of binder material-containing fibers containing polylactic acid as a binder material for fixing the plurality of biodegradable fibers to form a long laminated web. The biodegradable fibers are non-molten at the melting point of the polylactic acid. The punching step performs punching on the laminated web obtained in the laminating step using a needle. The heating step melts the binder material by heating the laminated web that has undergone the punching step. The cooling step cools the laminated web after the heating step to obtain a punched carpet having a non-woven fabric in which the entangled biodegradable fibers are fixed by a binder formed of polylactic acid as the non-woven fabric region.

[0011] In the punching step, it is preferable to perform punching on the laminated web being conveyed with the needle depth gradually decreasing as it moves downstream in the conveying direction.

Advantages of the Invention

[0012] According to the present invention, a punched carpet having biodegradability can be more easily manufactured.

Brief Description of the Drawings

[0013] [Figure 1] It is a schematic view of a punched carpet which is an embodiment. [Figure 2A] It is an explanatory view showing a fixing mode by a binder of rayon fibers. [Figure 2B] It is an explanatory view showing a fixing mode by a binder of rayon fibers. [Figure 2C] It is an explanatory view of a polylactic acid fiber as a binder material-containing fiber. [Figure 3A] It is an explanatory view showing another adhesion state of the binder to the rayon fibers. [Figure 3B] It is an explanatory view showing another adhesion state of the binder to the rayon fibers. [Figure 4] This is an explanatory diagram of the layer structure of a punch carpet, which is another embodiment. [Figure 5] This is a schematic diagram of the manufacturing equipment for punch carpet. [Figure 6] This is an explanatory diagram of the web layering method. [Modes for carrying out the invention]

[0014] The punch carpet 10 shown in Figures 1, 2A, and 2B is one embodiment of the punch carpet of the present invention and is formed in a long length. The punch carpet 10 may be cut into sheets of a desired size. For example, when transporting, the punch carpet 10 is rolled up and cut to a desired length and width according to the shape and size of the area to be laid, and then spread out flat and laid. The front and back of the punch carpet 10 are not particularly limited, and either the carpet surface 10A or 10B may be the surface that is exposed facing upwards. The area to be laid for the punch carpet 10 is not particularly limited and may be indoors or outdoors. Indoor areas to be laid may include areas that are walked on without shoes, such as houses and temples, as well as areas that are walked on with shoes, such as offices in buildings, corridors in exhibition venues, exhibition booths, event venues, and warehouses.

[0015] The punch carpet 10 comprises a plurality of rayon fibers 11, a plurality of polylactic acid fibers 12, and a binder 13 that fixes and holds the plurality of rayon fibers 11 and the plurality of polylactic acid fibers 12. The plurality of rayon fibers 11 and the plurality of polylactic acid fibers 12 are entangled, that is, intertwined with each other, and each of the rayon fibers 11 and polylactic acid fibers 12 is bent. The binder 13 is made of polylactic acid. The binder 13 fixes and holds the rayon fibers 11 and polylactic acid fibers 12 in an entangled state, and may exist in a discontinuous manner, such as scattered within the punch carpet 10, or it may be continuous. In this example, the binder 13 fixes the rayon fibers 11 and polylactic acid fibers 12 by covering and enclosing the areas where the fibers are in close proximity (hereinafter referred to as proximity areas). The adjacent areas may be adjacent to one rayon fiber 11 and another rayon fiber 11, adjacent to any part of one rayon fiber 11 and another part of it, adjacent to one polylactic acid fiber 12 and another polylactic acid fiber 12, adjacent to any part of one polylactic acid fiber and another part of it, or adjacent to one rayon fiber 11 and another polylactic acid fiber 12. In the punch carpet 10, a void 15 is formed by the rayon fiber 11 and the polylactic acid fiber 12, and the binder 13 does not close the void 15. In this way, the binder 13 partially adheres and fixes the rayon fiber 11 and the polylactic acid fiber 12. Because a void 15 is formed and the rayon fiber 11 and polylactic acid fiber 12 are partially adhered and fixed, the punch carpet 10 has cushioning (elasticity) and contributes to reducing fatigue when walking.

[0016] The punch carpet 10 has a nonwoven fabric region made of a single layer of nonwoven fabric. That is, the punch carpet 10 has a nonwoven fabric region where the entire area in the thickness direction is made of nonwoven fabric, and it does not have a base material that covers the carpet surfaces 10A and 10B. The base material is, for example, a base fabric (nonwoven fabric, knitted fabric, woven fabric, etc.) or a film made of resin that has been provided in conventional punch carpets. Therefore, at least the rayon fibers 11 and polylactic acid fibers 12 are exposed on each carpet surface 10A and 10B of the punch carpet 10. The binder 13 may be partially exposed on at least one of the carpet surfaces 10A and 10B together with the rayon fibers 11 and polylactic acid fibers 12, or it may be located inside the carpet surface in the thickness direction, recessed beyond the rayon fibers 11 and polylactic acid fibers 12, without being exposed. The punch carpet 10 may have a coating formed on the rayon fibers 11 and polylactic acid fibers 12 exposed on the carpet surfaces 10A and 10B by spray coating, depending on the desired purpose, such as improving flame retardancy. The raw materials for the coating can be either organic compounds or inorganic compounds. Examples of organic compounds include halogen compounds and organophosphorus compounds, while examples of inorganic compounds include metal hydroxides and boron compounds. The coating solution for spray coating is obtained by dissolving such raw materials for the coating in a solvent.

[0017] The rayon fibers 11 formed from rayon are an example of biodegradable fibers, and other biodegradable fibers may be used in addition to or substituted for the rayon fibers 11. In this example, the punch carpet 10 includes polylactic acid fibers in addition to the rayon fibers 11 as biodegradable fibers, and multiple polylactic acid fibers 12 are entangled in the same way as the rayon fibers 11, each being bent, and adjacent parts are fixed by the binder 13. The rayon fibers 11 and polylactic acid fibers 12 are also entangled, and adjacent parts are fixed by the binder 13. The biodegradable fibers only need to be stable and non-melting at the melting point of the polylactic acid that forms the binder 13. That is, the biodegradable fibers are fibers formed from a biodegradable polymer that is solid at the melting point of the polylactic acid that forms the binder 13, and it is more preferable that they are stable and non-melting at a temperature at least 5°C higher than the melting point of the component with the lowest melting point among the components that make up the binder material-containing fibers described later (in this example, the polylactic acid that forms the binder 13). This makes it easier to adjust the temperature in the heating process described later to a temperature that melts the polylactic acid, which forms the binder 13, while maintaining the fibrous state of the rayon fibers 11 and polylactic acid fibers 12. Natural fibers such as cotton and wool can also be used as biodegradable fibers. However, cotton and wool often contain fibers that are too short, as described later. Therefore, when using cotton or wool, it is preferable to use fibers that have been selected based on fiber length, especially when considering usage environments where the punch carpet 10 may be stepped on with shoes. Biodegradable fibers are preferable because they are regenerated fibers, have excellent biodegradability, reliably reduce the burden on the environment, and have a low percentage of fibers with extremely short lengths. Examples of regenerated fibers include rayon fibers, cupro fibers, and lyocell fibers. Thus, rayon fiber 11 is one example of a regenerated fiber.

[0018] Biodegradable fibers are monofilaments. However, they may also be multifilaments, which are bundles of monofilaments.

[0019] The punch carpet 10 may contain other fibers and binders other than rayon fibers 11, polylactic acid fibers 12, and binder 13, but such other fibers and binders should be biodegradable or their components should exist in nature and have little or no environmental impact. The biodegradable fibers may contain inorganic materials. For example, many phosphorus compounds, boron compounds, and silica compounds exist in nature and have little or no environmental impact, so they may be included. The inorganic materials contained in the biodegradable fibers may be in any shape, such as fine particles, fibers with a diameter that is approximately constant in the longitudinal direction, or needle-like shapes that are tapered. By including inorganic materials, the punch carpet 10 becomes more flame-retardant and fire-resistant. It is preferable that the punch carpet 10 does not contain organic matter that is not biodegradable, and this is the case in this example as well.

[0020] The length of the biodegradable fibers (hereinafter referred to as fiber length) is not particularly limited, but is preferably within the range of 20 mm to 100 mm. A fiber length of 20 mm or more is preferable because, compared to the case where the fiber length is less than 20 mm, the rayon fibers 11 and the binder material-containing fibers 16 (see Figure 2C) described later are more likely to intertwine in the punching process described later, thereby resulting in a stronger punch carpet 10 made of a single-layer nonwoven fabric. A fiber length of 100 mm or less is preferable because, compared to the case where the fiber length is longer than 100 mm, when creating the mixed fibers 63A (see Figure 5) described later, the rayon fibers 11 and the binder material-containing fibers 16 are less likely to intertwine with each other or with parts of the apparatus, thus preventing problems from occurring. The fiber length is more preferably within the range of 30 mm to 80 mm, and even more preferably within the range of 40 mm to 70 mm.

[0021] The diameter of the biodegradable fibers (hereinafter referred to as fiber diameter) is not particularly limited, but it is preferably within the range of 3 dtex (decitex) to 50 dtex in terms of fineness. A fiber diameter of 3 dtex or more is more preferable because it suppresses pilling (lint balls) more effectively than when the fiber diameter is less than 3 dtex. A fiber diameter of 50 dtex or less is more preferable because, compared to when the fiber diameter is thicker than 50 dtex, the carpet surface 10A and 10B of the punch carpet 10 becomes smoother, improving workability. The fiber diameter is more preferably within the range of 4 dtex to 40 dtex, and even more preferably within the range of 6 dtex to 30 dtex.

[0022] Multiple types of biodegradable fibers may be used in combination as biodegradable fibers. Different types mean that the biodegradable polymers constituting the biodegradable fibers are different, as in the case of rayon fiber 11 and polylactic acid fiber 12 in this example, as well as at least one of the following: the color of the biodegradable fibers, fiber length, fiber diameter, or the type of inorganic material contained. In this example, rayon fiber 11 and polylactic acid fiber 12, which have different types of biodegradable polymers, are used in combination, and first rayon fiber 11A (see Figure 5) and second rayon fiber 11B (see Figure 5), which have different colors, are used in combination to form a punch carpet 10 containing these. In the following description, when the first rayon fiber 11A and the second rayon fiber 11B are not distinguished, they will be referred to as rayon fiber 11.

[0023] In the manufacturing method of the punch carpet 10 described later, the binder 13 uses the binder material-containing fiber 16 shown in Figure 2C as its raw material. The binder material-containing fiber 16 has a coaxial structure comprising a core portion with a circular cross-section and a sheath portion covering the outer circumference of the core portion. The core portion constitutes the polylactic acid fiber 12 of the punch carpet 10, and the sheath portion is the binder material 13A that becomes the binder 13 of the punch carpet 10. However, the entire binder material-containing fiber 16 may be a binder material-containing fiber (not shown) consisting of the binder material 13A that becomes the binder 13. Both the polylactic acid fiber 12, which is the core portion, and the binder material 13A are formed from polylactic acid. Polylactic acid is a polymer in which lactic acid is polymerized by ester bonds, and has a structure in which -C(CH3)HC(=O)O- is a repeating unit. The polylactic acid can be poly-L-lactic acid (PLLA), poly-D-lactic acid (PDLA), or a copolymer of L-lactic acid and D-lactic acid. However, the polylactic acid constituting the polylactic acid fibers 12 and the polylactic acid constituting the binder material 13A must be different from each other, and the polylactic acid constituting the binder material 13A must have a lower melting point than the polylactic acid constituting the polylactic acid fibers 12 and the rayon constituting the rayon fibers 11. Rayon has no melting point, and softening and thermal decomposition occur upon heating, with a thermal decomposition temperature generally being 175°C or higher. In cases where there is no melting point, the thermal decomposition temperature may be used instead. In copolymers of L-lactic acid and D-lactic acid, the higher the proportion of D-lactic acid, the lower the melting point. In this example, the polylactic acid constituting the polylactic acid fiber 12 has a melting point of 170°C, and the polylactic acid constituting the binder material 13A has a melting point of 130°C. The polylactic acid fiber 12 is composed of PLLA based on its melting point, and the binder material 13A is composed of a copolymer of L-lactic acid and D-lactic acid. Thus, when using binder material-containing fibers 16 with a core-sheath structure made of polylactic acid as a raw material, it is preferable to have polylactic acid fibers 12 and binder material 13A composed of polylactic acid with different ratios of L-lactic acid and D-lactic acid. Since polylactic acid is a biodegradable plastic manufactured from plants such as corn and sugarcane, the punch carpet 10 can be obtained as a biodegradable material by using a binder 13 to fix and hold the rayon fibers 11 and polylactic acid fibers 12.

[0024] The fiber length of the binder material-containing fibers 16 (which is also the fiber length of the polylactic acid fibers 12) is not particularly limited, but it has been confirmed that the rayon fibers 11 are securely fixed with sufficient adhesive strength in the manufacturing method described later, for example, if they are in the range of 20 mm to 100 mm. The fiber diameter of the polylactic acid fibers 12 is not particularly limited, but it has been confirmed that the rayon fibers 11 are more securely fixed with sufficient adhesive strength in the punch carpet manufacturing method described later, if the fineness is in the range of 2 dtex to 20 dtex.

[0025] Here, the thickness of the punch carpet 10 is Tmm, and the weight is Wg / m 2 The area is calculated as 1 m² of either one of the carpet surfaces 10A or 10B. 2 This is the mass per unit area. The punch carpet 10 has a W / T of at least 125. By increasing the mass per unit thickness in the single-layer punch carpet 10 in this way, partial lifting from the floor surface is suppressed when laid on the floor surface. In addition, a W / T of at least 125 ensures sufficient 5% tensile stress, so even when laid and used in places where it is stepped on with shoes, such as exhibition halls, the occurrence of wrinkles and other deformations is suppressed, and durability is demonstrated. Wrinkling refers to the collapse of the flat shape when spread out, resulting in wavy deformation, wrinkles, etc., that occur in at least some areas. The punch carpet 10 preferably has a W / T in the range of 125 to 500. Even if the W / T exceeds 500, there is no extreme improvement in the suppression effect of partial lifting when laid and the occurrence of wrinkles in environments where it is stepped on with shoes, compared to when it is 500 or less. This is because a W / T of 500 or less is lighter than when it is 500, making it easier to transport and lay, and thus having superior handling properties. The punch carpet 10 is more preferably at least 160, and even more preferably at least 170.

[0026] The weight W is at least 300g / m 2is preferable. In the punched carpet 10 composed of a single-layer non-woven fabric region, when the basis weight is 300 g / m 2 or more, compared with the case where it is less than 300 g / m 2 , the effect of suppressing the occurrence of sagging during use is high. The basis weight W is more preferably in the range of 400 g / m 2 or more and 800 g / m 2 or less. When the basis weight W is 800 g / m 2 or less, compared with the case where it is larger than 800 g / m 2 , it is lighter than the case where it is 800 g / m 2 , so it is excellent in handling properties such as being easy to transport and lay. The basis weight W is more preferably in the range of 450 g / m 2 or more and 700 g / m 2 or less, and particularly preferably in the range of 500 g / m 2 or more and 600 g / m 2 or less.

[0027] When manufacturing the punch carpet 10, the mass proportion of binder material-containing fibers 16, which are raw materials, is preferably at least 10% when the total mass of all raw materials is 100%. By having binder material-containing fibers 16 at least 10% of the total mass of all raw materials, the adjacent areas of the rayon fibers 11 and polylactic acid fibers 12 are fixed to each other with greater adhesive strength, resulting in a punch carpet 10 with 5% greater tensile strength and elongation stress. As a result, the occurrence of warping and pilling is further suppressed. When manufacturing the punch carpet 10, the mass proportion of binder material-containing fibers 16 is preferably within the range of 10% to 60% of the total mass of all raw materials. A mass proportion of binder material-containing fibers 16 of 60% or less is preferable because, compared to a proportion greater than 60%, there are fewer adhesive areas due to the binder material 13A melted by heating in the heating process described later, thus maintaining the cushioning properties of the rayon fibers 11 and polylactic acid fibers 12 and reducing the burden during walking. When manufacturing the punch carpet 10, the mass percentage of the binder material-containing fibers 16 is more preferably in the range of 20% to 50% of the total mass of all raw materials, and even more preferably in the range of 30% to 40%.

[0028] The 5% tensile stress is the force required to stretch the punch carpet 10 by 5% in a given direction. The 5% tensile stress can be determined by the following method, and this method is used in this example. First, a rectangular test specimen with a long side length of 300 mm and a short side length of 50 mm is cut from the punch carpet 10. The direction along the long side of the test specimen is the tensile direction in the test. Two test specimens are prepared: one where the transport direction MD (see Figure 5) in the manufacturing process is along the long side, and another where the direction perpendicular to the transport direction MD is along the long side. The transport direction MD in the manufacturing process corresponds to the longitudinal direction of the long punch carpet 10, and the direction perpendicular to the transport direction corresponds to the width direction of the long punch carpet 10. Chucks with a width of 20 mm are attached to both ends of the test specimen, and the test specimen is set so that the gauge length is 200 mm. A tensile test is performed at a tensile speed of 100 mm / min. The tensile strength (N / 50 mm) when the test specimen is elongated by 5% is determined as the 5% tensile stress, and the tensile strength (N / 50 mm) and elongation (%) at fracture are measured. The tensile strength and elongation at fracture are measured according to the measurement method compliant with Japanese Industrial Standard JIS L1913. In this example, a Shimadzu Corporation Autograph AGS-5kNX tensile testing machine is used. In the following, the units for tensile strength and tensile stress may be expressed as N / 5 cm.

[0029] When the sum of the masses of the rayon fibers 11 and the polylactic acid fibers 12 is 100.0, the mass of the binder 13 (binder material 13A in the raw materials) is preferably in the range of 5.0 to 100.0. In this example, the mass of the rayon fibers 11 is the sum of the masses of the first rayon fiber 11A (see Figure 5) and the second rayon fiber 11B (see Figure 5). By having a binder 13 mass of 5.0 or more relative to the sum of the masses of the rayon fibers 11 and the polylactic acid fibers 12 (100.0), the rayon fibers 11 and the polylactic acid fibers 12 are fixed to each other with greater adhesive strength, resulting in a punch carpet 10 with a 5% greater tensile stress and tensile strength. It is preferable that the mass of the binder 13 relative to the mass sum of the rayon fibers 11 and polylactic acid fibers 12 (100.0) is 100.0 or less, as this results in a greater proportion of fibers remaining in a state of fiber form after the heating process compared to when the mass is greater than 100.0, thereby improving the cushioning properties of the punch carpet 10. It is more preferable that the mass of the binder 13 relative to the mass sum of the rayon fibers 11 and polylactic acid fibers 12 (100.0) be in the range of 10.0 to 70.0, and even more preferable that it be in the range of 15.0 to 50.0.

[0030] In the punch carpet 10, it is preferable that the 5% tensile stress in the longitudinal direction is greater than the 5% tensile stress in the width direction, and this is the case in this example as well. As a result, even when the punch carpet 10 is laid with its longitudinal direction aligned with the direction in which the laying area extends, such as in the aisles of an exhibition hall, and is used in environments where it is stepped on with shoes, the occurrence of warping is more reliably suppressed. In particular, the occurrence of warping at the edges (side edges) in the width direction is extremely suppressed. When the 5% tensile stress in the longitudinal direction is SL and the 5% tensile stress in the width direction is SW, it is more preferable that SL is within the range of SW × 1.2 or more and SW × 3.0 or less, and even more preferable that it is within the range of SW × 1.5 or more and SW × 2.5 or less.

[0031] In punch carpet 10, it is preferable that the 5% tensile stress SL in the longitudinal direction and the 5% tensile stress SW in the width direction are both 30 N / 5 cm or more, from the viewpoint of further suppressing warping. Furthermore, when punch carpet 10 is cut into a sheet, it is preferable that the 5% tensile stress in each of the two orthogonal directions within the carpet surface of the cut sheet of punch carpet 10 satisfies the preferred range of SL and SW described above.

[0032] Regarding the punch carpet 10, the tensile strength in the longitudinal direction and the tensile strength in the width direction are not particularly limited, but the greater the strength, the less likely holes are to occur due to use, which is preferable. From the viewpoint of more reliably suppressing holes due to use, the tensile strength in the longitudinal direction and the width direction are preferably 150 N / 5 cm or more. The tensile strength in the longitudinal direction and the tensile strength in the width direction are both the tensile strength at the time of breakage as described above.

[0033] The elongation rates in the longitudinal direction and the width direction of the punch carpet 10 are not particularly limited, but the smaller they are, the less likely twisting will occur when a large force is applied, which is preferable. From the viewpoint of more reliably suppressing twisting, it is preferable that the elongation rates in the longitudinal direction and the width direction are kept to a maximum of 75%. Both the elongation rate in the longitudinal direction and the elongation rate in the width direction are the elongation rates at the time of breakage as described above.

[0034] As long as the adjacent portions of the rayon fibers 11 and polylactic acid fibers 12 are fixed and held together, the binder 13 does not need to enclose and cover the adjacent portions, as shown in Figures 3A and 3B. In the embodiments shown in Figures 3A and 3B, the punch carpet 10 has a void 15 surrounded by the rayon fibers 11 and polylactic acid fibers 12, the binder 13 does not close the void 15, and the binder 13 partially adheres and fixes the rayon fibers 11 and polylactic acid fibers 12.

[0035] The punch carpet 30 shown in Figure 4 is another embodiment of the punch carpet of the present invention. The punch carpet 30 comprises a nonwoven fabric layer 31 made of nonwoven fabric and a coating layer 32 for improving or providing flame retardancy. The nonwoven fabric layer 31 is constructed in the same manner as the punch carpet 10 described above and has a single-layer structure. The coating layer 32 may be for improving or providing other functions in lieu of or in addition to flame retardancy. The coating layer 32 is formed in a film shape by applying a coating liquid, for example by roller coating, and drying the coating film. The coating can be performed by a well-known method, such as roller coating using a roller. The coating liquid can be obtained by dissolving the raw materials of the coating film described above in a solvent or dispersing them in a dispersion medium for spray coating as described above. The coating layer 32 may be provided on both sides of the nonwoven fabric layer 31. Thus, the punch carpet of the present invention, as in the punch carpets 10 and 30, has a single-layer structure in the nonwoven fabric region made of nonwoven fabric.

[0036] The punch carpet 10 can be manufactured, for example, by the punch carpet manufacturing equipment (hereinafter simply referred to as "manufacturing equipment") 40 shown in Figure 5. The manufacturing equipment 40 is equipped with first to third fiber opening devices 41A to 41C, a mixing device 42, a carding machine 45, a cross wrapper 46, a first punching machine 51, a second punching machine 52, a heating device 55, a winding device 56, etc., in this order from the upstream side.

[0037] The first to third fiber opening devices 41A to 41C each open the rayon fibers 11, specifically the first rayon fiber 11A and the second rayon fiber 11B, the polylactic acid fiber 12, and the binder material-containing fiber 16, which is the raw material for the binder 13, so that they can be easily mixed uniformly in the next mixing process (fiber opening process). In this example, since the fibers of the three raw materials mentioned above are used, three fiber opening devices, the first to third fiber opening devices 41A to 41C, are used, but the number of fiber opening devices is determined according to the number of types of raw material fibers used. The first rayon fiber 11A, the second rayon fiber 11B, and the binder material-containing fiber 16 are weighed to the desired mixing ratio and fed into the first fiber opening device 41A, the second fiber opening device 41B, and the third fiber opening device 41C.

[0038] The mixing device 42 comprises a mixing unit 61 and a quantitative supply unit 62, and a commercially available cotton blending machine can be used. The mixing unit 61 comprises a chamber 61a that separates a storage space containing first rayon fibers 11A, second rayon fibers 11B, and binder material-containing fibers 16 from the outside, and a feeder 61b provided at the downstream end of the chamber 61a. The chamber 61a uniformly mixes the opened first rayon fibers 11A, second rayon fibers 11B, and binder material-containing fibers 16 to form mixed fibers 63A (mixing process). The feeder 61b dispenses the mixed fibers 63A from an opening located above the conveyor belt 62a provided in the quantitative supply unit 62.

[0039] The quantitative supply unit 62 comprises a conveyor belt 62a formed in an annular shape and having no end, and a plurality of rollers 62b that support the conveyor belt 62a on their circumferential surface and rotate to move the conveyor belt in the longitudinal direction. The rollers 62b have a motor (not shown) and a drive controller (not shown), and under the control of the drive controller, the motor rotates in the circumferential direction at a predetermined speed. As the conveyor belt moves, the mixed fibers 63A are continuously supplied from the feeder 61b at a supply rate that is approximately constant per unit time, thereby guiding the mixed fibers 63A toward the carding machine 45 in a state where they are quantified to an approximately constant amount per unit area of ​​the belt surface of the conveyor belt 62a.

[0040] The carding machine 45, located downstream of the quantitative supply unit 62, has a relatively large diameter roller 66, a plurality of smaller diameter rollers 67, and a chamber 68 that houses the large diameter roller 66 and the smaller diameter rollers 67. The plurality of smaller diameter rollers 67 are arranged in a line in the circumferential direction of the large diameter roller 66, with their circumferential surfaces facing the circumferential surface of the large diameter roller 66. The smaller diameter rollers 67 are arranged at a predetermined distance from the large diameter roller 66, and both the large diameter roller 66 and the smaller diameter rollers 67 have motors (not shown) and drive controllers (not shown), and under the control of the drive controllers, each rotates at a predetermined speed. Multiple tapered protrusions (not shown) are provided on the circumferential surfaces of the large-diameter roller 66 and the small-diameter roller 67. When the quantified mixed fibers 63A are guided between the rotating large-diameter roller 66 and the small-diameter roller 67, the protrusions on these rollers scrape off the rayon fibers 11 and binder-containing fibers 16 that make up the mixed fibers 63A, loosening them and aligning the fiber direction in the longitudinal direction, resulting in a web 63B with uniform thickness and uniform basis weight (carding process). By adjusting the amount of mixed fibers 63A supplied from the feeder 61b to the conveyor belt 62a, the moving speed of the conveyor belt 62a, and the rotational speeds of the large-diameter roller 66 and the small-diameter roller 67, the yield is 15 g / m 2 More than 30g / m 2 It is preferable to use a web 63B with a basis weight within the following range, and in this example, a web 63B with a basis weight within this range is obtained.

[0041] The cross wrapper 46, located downstream of the card machine 45, is an example of a stacking device. It stacks the webs 63B that are continuously guided from the card machine 45 to form a stacked web 63C (stacking process). The cross wrapper 46 is an example of a stacking device for stacking webs, and commercially available devices can be used.

[0042] The cross wrapper 46 includes, for example, as shown in Figure 6, a conveyor belt 71 whose longitudinal direction coincides with a direction approximately perpendicular to the conveying direction MD of the web 63B guided from the card machine 45, a pair of rollers 72 that support the conveyor belt 71 on their circumferential surface and move it in its longitudinal direction, and a mounting section 73 that guides the guided web 63B onto the conveyor belt 71 and places it so that it overlaps. The configuration of the cross wrapper 46, including the components of the mounting section 73, and the mounting mechanism are not particularly limited, and known cross wrappers can be used. The mounting section 73 in this example is arranged above the conveyor belt 71 and includes a roller 73a extending in the longitudinal direction of the conveyor belt 71 and a support (not shown) that supports the roller 73a, a conveyor belt 73c arranged on the outer circumference of the roller 73a, and a shift mechanism (not shown) that displaces the roller 73a in the width direction perpendicular to the longitudinal direction of the conveyor belt 71. For example, by periodically displacing a drive motor (not shown) connected to the support of the roller 73a by electronic control, the roller 73a can be displaced in the width direction of the conveyor belt 71. The roller 73a is a drive roller that rotates in the circumferential direction. The web 63B guided from the carding machine 45 is placed on the conveyor belt 73c, and as the roller 73a rotates while periodically changing its rotational speed in accordance with the reciprocating displacement of the conveyor belt 71 in the width direction, the conveyor belt 73c moves at a constant speed, and the web 63B on this conveyor belt 73c is conveyed at a constant conveying speed. During this conveying, as the roller 73a is displaced to reciprocate in the width direction of the conveyor belt 71, the webs 63B on the moving conveyor belt 71 are sequentially stacked on the conveyor belt 71 with a shift equal to the movement of the conveyor belt 71, and are conveyed in the direction of movement of the conveyor belt 71. In this way, the stacked webs 63C are guided in a direction perpendicular to the conveying direction MD of the web 63B, with the conveying direction MD being MD. 2 The aforementioned W / T, which is the mass per unit thickness, can be adjusted by the number of layers to be stacked. The number of layers to be stacked can be adjusted by the relative speed between the transport speed of the web 63B and the transport speed of the stacked web 63C (the moving speed of the transport belt 71).

[0043] In Figure 5, commercially available punching machines can be used as the first punching machine 51 and the second punching machine 52 located downstream of the first punching machine 51. The first punching machine 51 and the second punching machine 52 punch the laminated web 63C obtained in the lamination process in the class wrapper 46 with multiple needles to entangle the rayon fibers 11 and binder material-containing fibers 16 (punching process). This entangles the rayon fibers 11 and binder material-containing fibers 16 that make up the laminated web 63C. This entanglement can increase the tensile stress and tensile strength by 5%.

[0044] While one punching machine may be used, it is preferable to use multiple machines arranged in series along the transport path of the laminated web 63C, as in this example. The punching process in this example has a first step performed by the first punching machine 51 and a second step performed by the second punching machine 52. Thus, when multiple punching machines are used, the punching process has multiple steps, such as the first step, the second step, and so on.

[0045] Upstream of the first punching machine 51, between the first punching machine 51 and the second punching machine 52, and downstream of the second punching machine 52, drive rollers DR1 to DR3, each equipped with a motor M, are provided, and these drive rollers DR1 to DR3 form a transport path for the laminated web 63C. In addition to these drive rollers DR1 to DR3, driven rollers that rotate under their own power may also be provided to support the laminated web 63C. The drive rollers DR1 to DR3 rotate independently at a set rotational speed by the motor M under the control of the drive controller C. As a result, the laminated web 63C that comes into contact with the circumferential surface of the drive rollers DR1 to DR3 is transported downstream through the first punching machine 51 and the second punching machine 52, and the longitudinal tension applied to the laminated web 63C during punching in the first punching machine 51 and the second punching machine 52 is adjusted. By adjusting this tension, the longitudinal draft rate is set to the desired draft rate. The draft ratio is the ratio of stretching, meaning the ratio of the length after stretching to the length before stretching. For example, if the length before stretching is 1 and the length is stretched to 4, the draft ratio is 4. The draft ratio is also the conveying speed ratio, so if two drive rollers aligned in the conveying direction MD are of the same diameter, it is the ratio of the rotational speed of the downstream drive roller to the rotational speed of the upstream drive roller. In the laminated web 63C after the carding process described above, the rayon fibers 11 and binder material-containing fibers 16 are oriented to stretch in the width direction of the laminated web 63C, and the 5% tensile stress in the width direction is much larger than the 5% tensile stress in the longitudinal direction. By stretching such a laminated web 63C to a draft ratio greater than 1, the direction of the fibers can be changed to the longitudinal direction, increasing the 5% tensile stress in the longitudinal direction and making it greater than the 5% tensile stress in the width direction. As a result, SL / SW can be made larger, and SL can be brought within the aforementioned range.

[0046] The drive roller DR1 forms a nip roller pair with the driven roller NR1, and the drive roller DR1 and driven roller NR1 nip the laminated web 63C and transport it downstream. The driven roller NR1 is equipped with a pressure regulator NC for adjusting the nip pressure (pressure in the thickness direction) on the laminated web 63C, and works in cooperation with the drive roller DR1 to apply the desired nip pressure. The same applies to the drive roller DR2 and driven roller NR2, and the drive roller DR3 and driven roller NR3. Because the laminated web 63C is transported in a nipped state in this way, the transport speed is adjusted more precisely, and as a result, punching is performed with a more precise control of the draft rate.

[0047] The draft ratio in the longitudinal direction during punching is preferably within the range of 1.0 to 2.0. A ratio of 1.0 or higher results in a punch carpet 10 with 5% improved tensile stress in the longitudinal direction compared to a ratio of less than 1.0. A ratio of 2.0 or lower results in 5% greater tensile stress in the width direction compared to a ratio greater than 2.0. The draft ratio in the longitudinal direction during the punching process is more preferably within the range of 1.1 to 1.8, and even more preferably within the range of 1.2 to 1.5.

[0048] The first punching machine 51 consists of a chamber 51a, a plurality of needles 51b, a support section 51c, etc. The chamber 51a separates the punching processing space where punching is performed from the external space, and the entrance to the laminated web 63C is formed to open on the upstream side in the conveying direction MD, and the exit is formed to open on the downstream side. In this example, the plurality of needles 51b are arranged with tapered tips facing downward. The support section 51c supports the plurality of needles 51b and has a shift mechanism (not shown). The shift mechanism moves the support section 51c in the vertical direction, thereby repeatedly piercing the laminated web 63C during conveying with the needles 51b from one web surface side (from above in the example shown in Figure 5) to perform punching. The second punching machine 52 consists of a chamber 52a, a plurality of needles 52b, a support section 52c, etc., and is configured similarly to the first punching machine 51 except that the plurality of needles 52b are arranged with tapered tips facing upward. Multiple needles 52b repeatedly pierce the laminated web 63C during transport from the other web surface side (from below in the example shown in Figure 5) to perform punching. When multiple punching machines are used in this manner, it is preferable to alternately punch the laminated web 63C from one web surface side and the other web surface side, as this results in a more uniform and higher degree of entanglement of the rayon fibers 11 and binder material-containing fibers 16 in the thickness direction of the laminated web 63C.

[0049] The punch density in the first punch machine 51 and the second punch machine 52 is 20 cm -2 More than 300cm -2 The following range is preferable: 20 cm -2 Therefore, 20cm -2Compared to cases where the density is less than 300cm, the degree of entanglement between the rayon fibers 11 and the binder material-containing fibers 16 increases, making them less likely to separate from each other, and as a result, the strength of the punch carpet 10 increases. Furthermore, the number of adjacent areas increases, and the degree of entanglement between the rayon fibers 11 and the binder material-containing fibers 16 also increases, so the binder material-containing fibers 16 are more likely to be present around adjacent areas. This results in a punch carpet 10 where adjacent areas are more reliably fixed with the binder 13. (300cm) -2 As a result of the following, 300cm -2 Compared to the case with a larger punch density, the needles 51b and 52b cut less of the rayon fibers 11 and the binder material-containing fibers 16, which include polylactic acid fibers 12, during punching. As a result, the strength of the punched carpet 10 is increased, and the carpet surfaces 10A and 10B have a clean surface with holes made by the needles 51b and 52b being less noticeable. The punch density is calculated based on the area of ​​the laminated web 63C per 1 cm². 2 This refers to the number of needle insertions (insertions) made by piercing (driving) the material into the area, and can be adjusted by the transport speed of the laminated web 63C and the vertical movement speed of the support sections 51c and 52c.

[0050] In cases where multiple punching machines are used, as in this example, it is preferable to gradually decrease the punch density as you move downstream in the conveying direction MD. As you move downstream, the degree of entanglement between the rayon fibers 11 and binder material-containing fibers 16 in the laminated web 63C increases due to repeated punching, causing the laminated web 63C to harden. However, by gradually decreasing the punch density downstream, the needles 51b and 52b are reliably inserted into the laminated web 63C at a predetermined needle depth, resulting in an effective punching process. As a result, the resulting punched carpet 10 will be less prone to twisting, fiber shedding, pilling, and hole formation, even in environments where it is stepped on with shoes. In this example, the punch density in the first punching machine 51 is 100 cm -2 More than 140cm -2 The following ranges apply, and the punch density in the second punch machine 52 is 85 cm². -2 More than 120cm -2The following ranges are used, and the punch density is lower than that of the first punch machine 51.

[0051] The needle depth in the first punching machine 51 and the second punching machine 52 is preferably within the range of 4 mm to 16 mm. By having a needle depth of 4 mm or more, the degree of entanglement between the rayon fibers 11 and the binder material containing fibers 16 is increased compared to when it is less than 4 mm, making it more difficult for them to separate from each other, and as a result the strength of the nonwoven fabric is increased. In addition, the number of adjacent areas increases, and the degree of entanglement between the rayon fibers 11 and the binder material containing fibers 16 is also increased, so the binder material containing fibers 16 are present in the vicinity of adjacent areas with a higher probability. As a result the punch carpet 10 is more reliably fixed with the binder 13 in adjacent areas, and the strength, in particular the 5% tensile stress in both the width direction and the longitudinal direction is improved. By having a needle depth of 16 mm or less, the carpet surfaces 10A and 10B have a cleaner surface with holes made by the needles 51b and 52b being less noticeable compared to when it is greater than 16 mm.

[0052] When using multiple punching machines as in this example, it is preferable to gradually decrease the needle depth as you move downstream in the conveying direction MD. This ensures that even if the laminated web 63C becomes progressively harder downstream, the needles 51b and 52b maintain the desired needle depth and penetrate reliably, resulting in an effective punching process. As a result, the resulting punched carpet 10 will be less prone to twisting, fiber shedding, pilling, and hole formation, even in environments where it is stepped on with shoes. Pilling is the phenomenon of lint balls forming. In this example, the needle depth in the first punching machine 51 is set to a range of 6 mm to 16 mm, and the needle depth in the second punching machine 52 is set to a range of 4 mm to 14 mm, and is lower than the needle depth in the first punching machine 51.

[0053] The heating device 55 includes a chamber 55a, a heating mechanism 55b, a conveyor belt 55c, and a plurality of rollers 55d. The chamber 55a separates the heating treatment space for heating the laminated web 63C that has been guided through the punching process from the external space, and is formed with an inlet for the laminated web 63C on the upstream side and an outlet on the downstream side in the conveying direction MD. The heating mechanism 55b adjusts the inside of the chamber 55a to a predetermined heating treatment temperature. The heating treatment temperature is higher than the melting point of the binder material 13A and lower than the temperature at which the fibrous components of the punch carpet 10 (rayon fibers 11 and polylactic acid fibers 12 in this example) are stably maintained. When the melting point of the binder material 13A is X (unit: °C), and the melting point of the fiber component with the lowest melting point among the fiber components of the punch carpet 10 (in this example, polylactic acid fiber 12 among rayon fiber 11 and polylactic acid fiber 12) is Y (unit: °C), the heat treatment temperature is more preferably in the range of (X+5)°C or higher and (Y-5)°C or lower. The texture of the resulting punch carpet 10 can be changed depending on the heat treatment temperature. Specifically, the lower the temperature is set within the range of 135°C to 165°C, the more reliably the melting of the polylactic acid fiber 12 is suppressed, and adhesion between the rayon fiber 11 and the polylactic acid fiber 12 in a state of direct contact without the binder 13 is suppressed, resulting in a punch carpet 10 with a soft texture, while the higher the temperature is set, the punch carpet 10 with a hard texture. Therefore, the heat treatment temperature may be set according to the desired texture. The heating mechanism 55b controls the temperature inside the chamber 55a by circulating heated air, adjusting it to the above-mentioned heat treatment temperature, supplying it into the chamber 55a, discharging it, adjusting it again to the above-mentioned heat treatment temperature, and supplying it back into the chamber 55a. However, the heating method by the heating mechanism 55b is not limited to this.

[0054] The conveyor belt 55c provided in the chamber 55a is formed in an annular shape and is endless, and a plurality of rollers 55d support the conveyor belt 55c on their circumferential surfaces. At least one of the plurality of rollers 55d has a motor (not shown) and a drive controller (not shown), and under the control of the drive controller, the motor rotates in the circumferential direction at a predetermined speed, thereby moving the conveyor belt 55c in the longitudinal direction. As a result, the laminated web 63C is conveyed and passes through the chamber 55a, whose internal temperature has been adjusted to the heat treatment temperature, and the binder material 13A melts during passage (heating process).

[0055] Outside the chamber 55a, the temperature is not specifically adjusted and is at room temperature (approximately 25°C). Therefore, the laminated web 63C, heated as described above, cools down when it exits the chamber 55a (cooling process). The cooling method in the cooling process may be natural cooling, such as air cooling, or it may be an active cooling method using cold air or the like. The cooling process solidifies the molten binder material 13A and fixes the rayon fibers 11 and polylactic acid fibers 12 in proximity. In this cooling process, it has been confirmed by optical microscope that the molten binder material 13A gathers and solidifies in proximity, resulting in the punch carpet 10 shown in Figures 2A-2B and 3A-3B.

[0056] The winding device 56 is equipped with multiple rollers 56a, 56b, etc., which support the conveyed punch carpet 10 in a roll shape. In this example, of the rollers 56a and 56b, the downstream roller 56b is used as the drive roller, and the punch carpet 10 is taken up and wound into a roll shape by the rotation of this roller 56b in the circumferential direction. As described above, the manufacturing equipment 40 allows for the simple and efficient production of long punch carpets 10 that do not have a base fabric and whose nonwoven fabric region has a single-layer structure. In addition, sheet-shaped punch carpets can be continuously produced by using a cutting device (not shown) that cuts the punch carpet 10 instead of the winding device 56. Alternatively, sheet-shaped punch carpets 10 can be produced by using a sheet manufacturing apparatus that includes a delivery unit (not shown) for feeding out the roll-shaped long punch carpet 10 and a cutting unit for cutting it into sheets. When manufacturing the punch carpet 30, the aforementioned coating liquid is applied to either the carpet surface 10A or 10B of the punch carpet 10 obtained as described above, and then the coating film is dried to form a covering layer 32. This makes it possible to manufacture a punch carpet 30 having the punch carpet 10 as a nonwoven fabric layer 31. [Examples]

[0057] [Example 1]~[Example 5] Six types of punch carpet 10 were manufactured using manufacturing equipment 40, and these were designated as Examples 1 to 5. First rayon fiber 11A was used as the first raw material, second rayon fiber 11B as the second raw material, and binder material-containing fiber 16 as the third raw material. The fiber diameter, fiber length, and mass percentage of each are shown in Table 1. The mass percentages in Table 1 are the percentages when the mass of the punch carpet is set to 100%.

[0058] The punch density, needle depth, and draft rate for the first and second punching processes, the heat treatment temperature in the heating process, and the hot air circulation volume for the chamber 55a are shown in Table 1. The hot air circulation volume is the amount of heated air supplied into the chamber 55a and the amount of heated air discharged from the chamber.

[0059] When each of the obtained punch carpets 10 was observed with an optical microscope, they all exhibited the characteristics shown in Figures 2A, 2B or 3A, 3B. Specifically, a void 15 surrounded by rayon fibers 11 and polylactic acid fibers 12 was formed, and the rayon fibers 11 and polylactic acid fibers 12 were partially fixed by the binder 13. Furthermore, the tensile strength, 5% elongation stress, and elongation rates in the longitudinal and width directions were determined for the punch carpets 10 obtained in Examples 1 to 5. These physical properties are shown in Table 1.

[0060] Each of the obtained punch carpets 10 was laid in a passageway where people wearing shoes walked, and its resistance to warping, perforation, and pilling was evaluated by visual observation. The evaluation results are shown in Table 1 as "Evaluation Results in Actual Use". The laying period was 3 days, and the total number of people passing through was approximately 1 million. Although there were slight differences in the total number of people passing through depending on the laying location, these differences were negligible for comparative evaluation. The evaluation was based on the evaluation results of Example 1 and carried out according to the evaluation criteria below. In Example 1, no warping, perforation, or pilling was observed after 1 day from laying, partially observed after 2 days, and observed throughout after 3 days, but within an acceptable range. A: The results were very good compared to the standard, and no abnormalities were observed even after 3 days. B; It was better than the standard, with suppression. C; was at the same level as the standard. D; Below standard

[0061] [Table 1]

[0062] [Reference example 1] To compare the above physical properties, a punch carpet made of a single-layer nonwoven fabric was manufactured using polypropylene fibers and fibers made of polyethylene-polypropylene copolymer as binder material-containing fibers as raw materials, and this was used as a reference example. The polypropylene fibers were used as the fiber component of the punch carpet, and the fibers made of polyethylene-polypropylene copolymer were used as binder material-containing fibers. Unlike the binder material-containing fiber 16 used in the example, which has a core and a sheath, this binder material-containing fiber has no core and a sheath, and the entire fiber is made of polyethylene-polypropylene copolymer as a binder material. Polyethylene-polypropylene copolymer has a lower melting point than polypropylene. The raw materials and physical properties are shown in Table 1. The punch carpet was manufactured by performing a fiber opening process, a mixing process, a carding process, a lamination process, a punching process, a heating process, and a winding process. In this reference example, since the raw materials are different from those in the example, the manufacturing conditions such as the punching process and heating process are omitted. For the heating process, the heat treatment temperature and the hot air circulation volume are shown in Table 1. "<" in the heat treatment temperature means less than. The physical properties of the obtained punch carpet were determined in the same manner as those of the punch carpet 10 obtained in Examples 1 to 6, and are shown in Table 1. [Explanation of symbols]

[0063] 10, 30 Punch carpet 10A, 10B Carpet surface 31 Non-woven layer 11, 11A, 11B Rayon fiber 12 Polylactic acid fiber 13 Binders 13A Binder Material 16 Binder material-containing fibers 40 Punch carpet manufacturing equipment 42 Mixing equipment 45 card machines 46 Cross Trumpet 51, 52 First and second punching machines 51b, 52b Needle 55 Heating device 63A Blended Fiber 63B Web 63C Laminated Web

Claims

1. The nonwoven fabric region, composed of nonwoven fabric, has a single-layer structure. The aforementioned nonwoven fabric is Multiple entangled biodegradable fibers, The biodegradable fibers are fixed and a binder formed of polylactic acid is used. Equipped with, The biodegradable fibers are non-melting at the melting point of the polylactic acid forming the binder in the punch carpet.

2. Thickness: T mm, Basis weight: Wg / m ２ When that happens, The punch carpet according to claim 1, wherein the W / T is at least 125.

3. The punch carpet according to claim 1 or 2, wherein the binder is at least 10% by mass.

4. The punch carpet according to claim 1 or 2, wherein the biodegradable fiber is a regenerated fiber.

5. The punch carpet according to claim 4, wherein the regenerated fiber is rayon fiber.

6. A method for manufacturing punch carpets in which the nonwoven fabric region, composed of nonwoven fabric, has a single-layer structure. A lamination process is performed in which a web is formed from a mixture of multiple biodegradable fibers and multiple binder-containing fibers containing polylactic acid as a binder material to fix the multiple biodegradable fibers, and the pre-degradable fibers are not melted at the melting point of the polylactic acid. The laminated web obtained in the lamination process is subjected to a punching process using a needle, A heating step is performed in which the binder material is melted by heating the laminated web that has undergone the punching step, A cooling step is performed to obtain a punch carpet in which the nonwoven fabric region is formed by cooling the laminated web after the heating step, in which the entangled biodegradable fibers are fixed by a binder formed of polylactic acid. A method for manufacturing punch carpet having [a certain feature].

7. The punching process described above is: The method for manufacturing a punch carpet according to claim 6, wherein the laminated web is punched while being transported, with the needle depth gradually decreasing as it moves downstream in the transport direction.

Images