Three-dimensional knitted fabric and vehicle interior material including same

Abstract

Provided are: a three-dimensional knitted fabric in which mesh distortion due to excessive elongation caused by a tensile load during seat installation or the like is suppressed, and that has Taber abrasion resistance and scratch resistance according to an ASTM method; and a vehicle interior material that includes the three-dimensional knitted fabric. The present invention relates to a three-dimensional knitted fabric and a vehicle interior material that includes the three-dimensional knitted fabric, the three-dimensional knitted fabric including a front layer knitted fabric, a back layer knitted fabric, and a connecting thread that connects the front layer knitted fabric and the back layer knitted fabric, the three-dimensional knitted fabric characterized in that: the front layer knitted fabric includes a front surface layer positioned on the outermost side of the three-dimensional knitted fabric, and a shape-fixing layer that is positioned farther inward in the three-dimensional knitted fabric than the front surface layer and that includes knit loops formed at the same positions as knit loops included in the front surface layer; the knitted fabric density after finishing is 30 to 64 courses / inch inclusive; and the ratio (A) of the number of knit loops included in the front surface layer to the number of knit loops included in the shape-fixing layer is more than 100% and 400% or less.

Description

Three-dimensional knitted fabric and vehicle interior material including the same

[0001] The present invention relates to a three-dimensional knitted fabric and a vehicle interior material including the same.

[0002] Conventionally, three-dimensional knitted fabrics composed of two layers of knitted fabric, one on the front side and one on the back side, and a connecting yarn connecting the two layers of knitted fabric have cushioning properties in the thickness direction by using monofilament as the connecting yarn, and furthermore, by making the knitted fabrics on the front and back sides into a mesh structure, high breathability is ensured, and they are widely used in applications such as seat covers and bedding as a cushioning material that is cool and prevents stuffiness.

[0003] Patent Document 1 below discloses that a skin material made of a three-dimensional knit fabric, in which the outer surface of the knitted fabric of the surface layer is the surface that comes into contact with the human body and the stitch density of the surface layer is 11,500 or more and 20,000 or less, can suppress pilling even when the surface is rubbed by the hook part of a hook-and-loop fastener.

[0004] Furthermore, Patent Document 2 below discloses that in a three-dimensional knitted fabric having at least one mesh surface, reinforcing threads are woven into the openings of the mesh to stabilize the shape of the mesh.

[0005] International Publication No. 2022 / 202815 International Publication No. 2007 / 097363

[0006] However, the three-dimensional knitted fabric described in Patent Document 1 has a dense knitted surface, which provides good durability against the irritation of rubbing the surface with hard protrusions such as hooks of a hook-and-loop fastener (hereinafter also referred to as "scratch resistance") and Taber abrasion resistance according to the JASO M403A method, but does not take into consideration the ASTM D3884-09 method, which specifies even harsher conditions, or pattern collapse due to stretching of the knitted fabric.Furthermore, the three-dimensional knitted fabric described in Patent Document 2 has improved stability of the mesh form by weaving reinforcing yarns into the openings of the mesh knitted fabric, but does not take into consideration scratch resistance, Taber abrasion resistance, or pattern (stitch) collapse due to stretching of the knitted fabric.

[0007] In view of the above-mentioned state of the prior art, the problem that the present invention aims to solve is to solve the problems of the above-mentioned prior art and to provide a three-dimensional knitted fabric that achieves a good feel in a three-dimensional knitted fabric, while suppressing stitch collapse due to excessive elongation when a tensile load is applied, such as when a seat is installed, and that has Taber abrasion resistance and scratch resistance according to the ASTM method, and a vehicle interior material that includes the three-dimensional knitted fabric.

[0008] As a result of extensive research and experimentation to solve the above-mentioned problems, the inventors unexpectedly discovered that the above-mentioned problems could be solved by a three-dimensional knitted fabric comprising a surface layer knitted fabric, a back layer knitted fabric, and a connecting yarn connecting the surface layer knitted fabric and the back layer knitted fabric, wherein at least one of the surface layer knitted fabric n and the back layer knitted fabric comprises a surface layer located on the outside of the three-dimensional knitted fabric, and a shape-fixing layer located on the inside of the three-dimensional knitted fabric and including knit loops formed in the same positions as the knit loops included in the surface layer, and this led to the completion of the present invention.

[0009] That is, the present invention is as follows: [1] A three-dimensional knit fabric including a surface layer knitted fabric, a back layer knitted fabric, and a connecting yarn connecting the surface layer knitted fabric and the back layer knitted fabric, wherein the surface layer knitted fabric includes a surface layer located on the outermost side of the three-dimensional knit fabric, and a shape-fixing layer located inside the three-dimensional knit fabric relative to the surface layer and including knit loops formed at the same positions as the knit loops included in the surface layer, wherein the knit density of the surface layer knitted fabric after finishing is 30 courses / inch or more and 64 courses / inch or less, and the ratio (A) of the number of knit loops included in the surface layer to the number of knit loops included in the shape-fixing layer is more than 100% and 400% or less. [2] The three-dimensional knit fabric according to [1] above, wherein the ratio (A) of the number of knit loops included in the surface layer to the number of knit loops included in the shape-fixing layer is 150% or more. [3] The three-dimensional knit fabric according to [1] or [2] above, wherein knit loops separated by one wale or more in the shape-fixing layer are connected by sinker loops. [4] The three-dimensional knit according to any one of [1] to [3] above, wherein the shape-fixing layer is a Denbigh knit. [5] The three-dimensional knit according to any one of [1] to [4] above, wherein the sum of the finenesses of the yarns forming each knit loop in all knit loops included in the knitted fabric of the surface layer is 100 dtex or more and 1000 dtex or less. [6] The three-dimensional knit according to [5] above, wherein the sum of the finenesses of the yarns forming each knit loop in all knit loops included in the knitted fabric of the surface layer is 250 dtex or more and 1000 dtex or less. [7] The three-dimensional knit according to any one of [1] to [6] above, wherein, among the knit loops included in the knitted fabric of the surface layer, for all knit loops including connecting yarns, the value obtained by dividing the fineness of the yarns other than the connecting yarn forming each knit loop by the fineness of the connecting yarn is 2.8 or more. [8] A three-dimensional knitted fabric as described in [7], wherein, among the knit loops included in the surface knitted fabric, in all knit loops including connecting yarns, the value obtained by dividing the fineness of the yarns other than the connecting yarns forming each knit loop by the fineness of the connecting yarn is 3.0 or more.[9] The three-dimensional knitted fabric according to any one of [1] to [8], wherein the surface layer knitted fabric has a stitch density of 11,500 or more and 20,000 or less, calculated by the following formula: Stitch density M = N × √D {where N is the number of stitches (stitches) of the surface layer knitted fabric per 2.54 cm square, and D is the total fineness (dtex) of the fibers forming one stitch of the surface layer knitted fabric.}

[10] The three-dimensional knitted fabric according to any one of [1] to [9], wherein the constant load set rate when a tensile load of 10 kg is applied in the warp direction of the three-dimensional knitted fabric for 10 minutes is 3% or less.

[11] The three-dimensional knitted fabric has an air permeability of 33 cc / cm, passing from the connecting layer toward the surface knitted fabric. ２ / sec or more.

[12] The three-dimensional knitted fabric according to any one of [1] to

[11] above, wherein at least one of the knitted fabric of the surface layer and the knitted fabric of the back layer contains a heat-sealing yarn.

[13] A vehicle interior material comprising the three-dimensional knitted fabric according to any one of [1] to

[12] above, and wherein the knitted fabric of the surface layer faces the interior of a vehicle.

[14] The vehicle interior material according to

[13] above, which is a covering material for a seat.

[0010] According to the present invention, there are provided a three-dimensional knitted fabric which suppresses stitch collapse due to excessive elongation when a tensile load is applied, such as when a seat is installed, and which has Taber abrasion resistance and scratch resistance according to the ASTM method, and a vehicle interior material containing the same.

[0011]

[0013] An embodiment of the present invention is a three-dimensional knit fabric including a surface layer knitted fabric, a back layer knitted fabric, and a connecting yarn connecting the surface layer knitted fabric and the back layer knitted fabric, wherein the surface layer knitted fabric includes a surface layer located on the outermost side of the three-dimensional knit fabric, and a shape-fixing layer located inside the three-dimensional knit fabric relative to the surface layer and including knit loops formed at the same positions as the knit loops included in the surface layer, wherein the knit density of the surface layer knitted fabric after finishing is 30 courses / inch or more and 64 courses / inch or less, and the ratio (A) of the number of knit loops included in the surface layer to the number of knit loops included in the shape-fixing layer is more than 100% and 400% or less.

[0012] The three-dimensional knit fabric of this embodiment includes a three-dimensional knit fabric composed of the surface layer knitted fabric, the back layer knitted fabric, and a connecting yarn connecting the surface layer knitted fabric and the back layer knitted fabric. Here, the surface layer refers to the layer exposed to the interior surface of the vehicle when used in a vehicle interior material. The three-dimensional knit fabric is knitted using a double Russell warp knitting machine or a double circular knitting machine. The density of the knitted fabric can be set as desired, but the knitted fabric density after finishing is preferably 30 courses / inch to 64 courses / inch, and 35 courses / inch to 50 courses / inch. Having a knitted fabric density after finishing of 30 courses / inch to 64 courses / inch can achieve a suitable tactile feel as a vehicle interior material and ensure suitable breathability when seated. To achieve the above knitted fabric density, a knitting machine gauge of 14 to 32 gauge is used, with 18 to 28 gauge being preferred. Furthermore, the on-machine course density during knitting can be set as desired, but from the viewpoint of adjusting the finished knitted fabric density to the above-mentioned preferred range, in the case of a double Russell knitting machine, knitting is preferably performed at a density of 29 courses / inch to 40 courses / inch, and more preferably at a density of 33 courses / inch to 40 courses / inch. If the density is 29 courses / inch or more, the stitches do not become loose and abrasion resistance is improved. On the other hand, if the density is 40 courses / inch or less, loops tend to come off the knitting needles during knitting, making knitting easier.

[0013] The three-dimensional knitted fabric of this embodiment is characterized in that the surface knitted fabric includes a surface layer located at the outermost side of the three-dimensional knitted fabric, and a shape-fixing layer located inside the three-dimensional knitted fabric relative to the surface layer and including knit loops formed at the same positions as the knit loops included in the surface layer.

[0014] The surface layer is the outermost layer of the three-dimensional knitted fabric, and is the part that greatly affects the design of the three-dimensional knitted fabric. The surface layer can have any design depending on the desired design.

[0015] The shape-fixing layer is located inside the surface layer and contains knit loops formed at the same positions as the knit loops in the surface layer. "Same positions" means that the knit loops in the shape-fixing layer and the knit loops in the surface layer are knitted at the same course positions and wale positions. Because they are knitted using the same needles at the same timing, the respective loops overlap at these same positions. Whether the knit loops are formed at the same positions can be confirmed by checking whether the needle loops in the surface layer and the shape-fixing layer overlap. By providing the shape-fixing layer, the knit loops forming the surface layer are fixed, preventing stitch collapse due to excessive stretching of the knitted fabric and improving Taber abrasion resistance and scratch resistance. It is preferable that the shape-fixing layer is not exposed on the surface so as not to affect the design of the three-dimensional knitted fabric. The shape-fixing layer can have any design, but in order to improve Taber abrasion resistance and scratch resistance by fixing adjacent wales in the surface layer and suppressing the movement of the knit loops, a design in which knit loops spaced one wale or more apart are connected by sinker loops is preferred, and a Denbigh design in which knit loops spaced one wale apart are connected by sinker loops is more preferred from the viewpoint of suppressing stitch collapse due to warp elongation of the knitted fabric. Furthermore, from the same viewpoint as above, in the three-dimensional knit fabric of this embodiment, the ratio (A) of the number of knit loops in the surface layer to the number of knit loops in the shape-fixing layer is more than 100% and not more than 400%, preferably more than 100% and not more than 300%, more preferably 150% to 300%, and even more preferably 200% to 300%. The number of knit loops in the shape-fixing layer and the surface layer can be determined by counting the needle loops in the corresponding layers.

[0016] The shape-fixing layer can be formed, for example, by yarn fed from a separate reed located inside the reed used to knit the surface layer in a double Russell knitting machine. Any method can be used to knit the shape-fixing layer. For example, it is preferable to feed yarn from a reed through which the yarn is passed all in, so that the loops of the shape-fixing layer overlap all of the loops of the knitted fabric of the surface layer.

[0017] The fineness of the fibers used in the shape-fixing layer is preferably 50 dtex or more and 150 dtex or less, more preferably 50 dtex or more and 120 dtex or less, and even more preferably 60 dtex or more and 120 dtex or less, from the viewpoints of fixing the surface layer to prevent stitch collapse, improving Taber abrasion resistance and scratch resistance, and preventing the shape-fixing layer from being exposed on the surface.

[0018] The fiber materials used for the front and back knitted fabrics are not limited, and may be a single material or a composite of multiple materials by blending, plying, blending, interweaving, etc. However, from the viewpoints of raw yarn strength and light resistance, polyethylene terephthalate long fibers are preferably used. Furthermore, the fibers used for the front and back knitted fabrics are preferably 100% polyethylene terephthalate fibers in terms of ease of recycling, such as material recycling and chemical recycling. Furthermore, from the viewpoint of increasing the pull-out resistance of single fibers and improving scratch resistance, the polyethylene terephthalate fiber is preferably false-twisted yarn, interlaced yarn, or twisted yarn. The fibers used for the front and back knitted fabrics are preferably spun yarn (yarn colored by kneading pigments, etc.) or yarn-dyed yarn in order to suppress changes in the properties of the three-dimensional knitted fabric due to dyeing, and more preferably spun yarn, which eliminates the need for a dyeing process.

[0019] The fineness of the fibers used in the front and back knitted fabrics is preferably 50 dtex to 500 dtex, more preferably 50 dtex to 250 dtex, and even more preferably 60 dtex to 250 dtex, from the viewpoint of suppressing stitch collapse due to warp elongation. From the same viewpoint, in all knit loops included in the knitted fabric on the side having the shape-fixing layer, of the front and back knitted fabrics, the total fineness of the yarns forming each knit loop is preferably 100 dtex to 1200 dtex, more preferably 100 dtex to 1000 dtex, even more preferably 250 dtex to 1000 dtex, and particularly preferably 250 dtex to 700 dtex. When the fibers used for the front and back knitted fabrics are multifilaments, the single yarn fineness is preferably 1 dtex or more and 6 dtex or less, more preferably 3 dtex or more and 6 dtex or less, which increases the strength of the single yarn.

[0020] The fiber material used for the connecting yarn may be the same as the fiber used for the knitted fabric of the front layer and the knitted fabric of the back layer described above.

[0021] The fiber used for the connecting yarn may be either a multifilament or a monofilament, but is preferably a monofilament. When a monofilament is used for the connecting yarn, the fineness thereof is preferably 30 dtex or more and 300 dtex or less, more preferably 50 dtex or more and 200 dtex or less, in order to suppress the monofilament from protruding from the knitted fabric surface and to maintain good cushioning properties.

[0022] If the connecting yarns protrude from the surface of the knitted fabric of a three-dimensional knit, they will easily get caught on protrusions such as the hook portions of hook-and-loop fasteners, reducing scratch resistance. Therefore, it is desirable that the stitches of the fibers forming the surface knitted fabric press down the stitches of the connecting yarns so that the connecting yarns do not protrude from the outer surface of the surface knitted fabric (i.e., the seating surface of the seat cover material).To achieve this, among the knit loops included in the knitted fabric on the side having the shape-fixing layer, for all knit loops including the connecting yarns, the value obtained by dividing the fineness D1 of the yarns other than the connecting yarns forming each knit loop by the fineness D2 of the connecting yarn (hereinafter also referred to as "D1 / D2") is preferably 2.8 or more, and more preferably 3.0 or more.

[0023] In the three-dimensional knitted fabric of this embodiment, it is preferable that the knitting structure of the surface layer knitted fabric and the back layer knitted fabric, which do not include the surface layer and shape-fixing layer, use at least two reeds and, when supplying yarn from the guide bar, have a mesh structure with a yarn withdrawal arrangement such as 1-in-1-out or 2-in-2-out.

[0024] In the three-dimensional knit fabric of this embodiment, the stitch density of the surface layer knitted fabric, calculated by the following calculation formula: stitch density M = N × √D {where N is the number of stitches (in pieces) of the surface layer knitted fabric per 2.54 cm square, and D is the total fineness (dtex) of the fibers forming one stitch of the surface layer knitted fabric}, is preferably 11,500 or more and 20,000 or less. Here, "the total fineness (dtex) of the fibers forming one stitch of the surface layer knitted fabric" refers to the total fineness of only the fibers forming the stitches, excluding the fineness of the connecting yarns and fibers that do not form stitches, such as insertion knitting.

[0025] When the stitch density of the surface knitted fabric is 11,500 or more, protrusions such as hooks of a hook-and-loop fastener are less likely to get caught on the monofilaments of the stitches of the surface layer, and the monofilaments are less likely to be cut and become frayed. When the stitch density of the surface knitted fabric is 20,000 or less, the breathability of the surface knitted fabric can be increased, heat transfer and moisture transfer due to air convection can be more easily caused, and when used in vehicle interior materials, the feeling of coolness when sitting or when touching the fabric tends to be improved and the feeling of stuffiness can be reduced. From the viewpoint of further suppressing fraying caused by protrusions and improving the feeling of coolness and stuffiness, the preferred range of the stitch density of the surface knitted fabric is 13,000 or more and 19,000 or less, and more preferably 14,000 or more and 19,000 or less.

[0026] The three-dimensional knit fabric of this embodiment preferably has a constant load set rate of 3% or less when a load of 10 kg is applied to the fabric in the warp direction for 10 minutes, then the load is removed and the fabric is allowed to stand for 10 minutes, from the viewpoint of preventing excessive elongation during sheet tensioning and preventing stitch collapse. A detailed method for measuring the constant load set rate will be described later.

[0027] The three-dimensional knitted fabric of this embodiment transfers heat and moisture from the human body when sitting, providing good coolness and preventing stuffiness, and has an air permeability of 33 cc / cm from the layer between the surface knitted fabric and the back knitted fabric of the three-dimensional knitted fabric (hereinafter also referred to as the "connecting layer") to the surface knitted fabric. ２ / sec or more, and more preferably 40 cc / cm ２ / sec or more, and more preferably 50 cc / cm ２ / sec or more.

[0028] In this specification, the term "air permeability that penetrates from the layer between the surface knitted fabric and the back knitted fabric of a three-dimensional knitted fabric toward the surface knitted fabric" refers to the air permeability of air that enters through the cross sections of the four sides of the three-dimensional knitted fabric, passes through the connecting layer, and penetrates the surface knitted fabric when measuring the air permeability of a three-dimensional knitted fabric in accordance with the suction conditions of JIS L1096 Air Permeability Testing Method (Method A), using a test piece of the three-dimensional knitted fabric with a size of 15 cm square, placing the surface knitted fabric side down in the opening of an air permeability tester, and placing a 3 mm thick, 20 cm square silicone rubber plate on the outer surface of the back knitted fabric to block the air from permeating the back knitted fabric.

[0029] The air permeability of a three-dimensional knitted fabric, measured by the commonly used JIS L1096 air permeability test method (method A), passing from the back layer knitted fabric to the surface layer knitted fabric, is 60 cc / cm ２ / sec or more, and more preferably 70 cc / cm ２ / sec or more, more preferably 90cc / cm ２ / sec or more. The air permeability from the knitted fabric of the back layer to the knitted fabric of the surface layer is 60 cc / cm ２ By setting the thickness to 1 / sec or more, the material is more suitable as a seat covering material to be used in combination with a cushion member incorporating a ventilation system.

[0030] In the three-dimensional knit fabric of this embodiment, from the viewpoint of fixing the stitches of the surface layer to prevent stitch collapse and improving Taber abrasion resistance and scratch resistance, it is preferable that at least one of the surface layer knitted fabric and the back layer knitted fabric, particularly the shape-fixing layer, contains a heat-sealed yarn. Here, "heat-sealed yarn" refers to a yarn having a lower melting point than other fibers contained in the surface layer knitted fabric and the back layer knitted fabric. The heat-sealed yarn preferably has a melting point of 200°C or less, more preferably 180°C or less. The material of the low-melting point yarn is not limited, and multiple materials may be combined by blending, plying, blending, etc., but from the viewpoint of strength and light resistance, long fibers of polyethylene terephthalate-based fibers are preferably used.

[0031] The thickness of the three-dimensional knitted fabric of this embodiment can be set arbitrarily, but is preferably 2 mm or more and 12 mm or less, more preferably 2.5 mm or more and 8 mm or less, in view of the ease of sewing and handling as a skin material. The basis weight of the three-dimensional knitted fabric can be set arbitrarily, but is preferably 150 to 1000 g / m ２ , more preferably 400 to 900 g / m ２ is.

[0032] In the finishing method for the three-dimensional knit fabric constituting the three-dimensional knit fabric of this embodiment, in the case of a three-dimensional knit fabric using yarn-dyed yarn or spun-dyed yarn, the grey fabric can be finished through processes such as scouring and heat setting, but in terms of process simplification, finishing by heat setting alone is more preferable. In the case of a three-dimensional knit fabric in which the connecting yarn or the fibers used in the surface layer knitted fabric and the back layer knitted fabric are uncolored, the grey fabric can be finished through processes such as presetting, scouring, dyeing, and heat setting.

[0033] The three-dimensional knitted fabric of this embodiment is suitably used as an interior material for a vehicle, with the knitted fabric including the shape-fixing layer of the front and back layer knitted fabrics facing the interior side.

[0034] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. The methods for measuring various physical properties of the three-dimensional knitted fabrics used in the examples and comparative examples are as follows.

[0035] (a) The ratio (%) of the number of knit loops contained in the surface layer to the number of knit loops contained in the shape-fixing layer (A) A test piece 100 mm wide x 100 mm long is taken, with the weft direction of the three-dimensional knit fabric as the width direction and the warp direction as the length direction, and the loops in the shape-fixing layer and the surface layer are counted and calculated using the following formula. Measurements are taken at three locations and the average value is calculated.

[0036] (b) Constant load set rate (%) when a tensile load of 10 kg is applied in the warp direction for 10 minutes. A test piece 80 mm wide x 250 mm long was taken, with the weft direction of the three-dimensional knitted fabric as the width direction and the warp direction as the length direction, and a 100 mm benchmark was drawn in the length direction at the center of the width and length directions of the test piece. The test piece was attached to a constant load elongation tester FLM-3M manufactured by Daiei Scientific Instruments Co., Ltd., and weights were attached so that the total tensile load applied in the length direction of the test piece was 10 kg. After applying a tensile load of 10 kg for 10 minutes, the test piece was removed and left to stand on a horizontal table for 10 minutes, and the length of the benchmark was measured in that state, and the value was calculated using the following formula: {where L1 is the length (mm) of the marked line 10 minutes after the load is removed.} Measurements are taken at five locations and the average value is calculated.

[0037] (c) Stitch collapse rate (%) when a tensile load of 10 kg is applied in the warp direction A test piece 80 mm wide x 250 mm long was taken with the weft direction of the three-dimensional knitted fabric as the width direction and the warp direction as the length direction, and marks were made at two points 2.5 cm apart in the length direction and two points 2.5 cm apart in the width direction from the center of the test piece. The test piece was attached to a constant load elongation tester FLM-3M manufactured by Daiei Scientific Instruments Co., Ltd., and weights were attached so that the total load applied in the length direction of the test piece was 10 kg. After applying a tensile load of 10 kg for 10 minutes, the length between the marks in the length direction and the length between the marks in the width direction were measured in this state, and the following formula was used: The stitch collapse rate is calculated using the formula: {where L2 is the distance (mm) between two points in the length direction after 10 minutes when multiplied by 10 kg, and L3 is the distance (mm) between two points in the width direction after 10 minutes when multiplied by 10 kg.} Measurements are taken at three locations, and the average value is calculated.

[0038] (d) Air permeability (cc / cm) from the connecting layer to the front knitted fabric ２ / sec) Using a Takayama Reed Co., Ltd. air permeability tester FX3300 Laboair IV, a test piece of 15 cm square three-dimensional knit fabric was placed with the front knitted fabric side down in the opening of the air permeability tester, a 3 mm thick, 20 cm square silicone rubber plate was placed on the outer surface of the back knitted fabric, and the test head of the air permeability tester was pressed against it and fixed with a clamp, and the air permeability that enters from the connecting layer of the cross section of the four sides of the three-dimensional knit fabric and passes through the front knitted fabric was measured under suction conditions in accordance with JIS L1096 Air Permeability Test Method (Method A).

[0039] (e) Air permeability (cc / cm) from the back layer knitted fabric to the front layer knitted fabric ２ / sec) Using a Takayama Reed FX3300 Laboair IV air permeability tester, the air permeability from the back knitted fabric to the front knitted fabric of a three-dimensional knitted fabric is measured in accordance with JIS L1096 air permeability test method (method A).

[0040] (f) Scratch resistance (grade) Using a flat abrasion tester manufactured by Daiei Scientific Instruments, a three-dimensional knitted fabric with a test piece size of 8 cm wide and 31 cm long is placed on the flat abrasion table of the flat abrasion tester with the surface knitted fabric facing up, and both ends are fixed with clamps. Next, a Velcro (registered trademark) A8693Y.71 (length 5 cm) manufactured by Kuraray Fastening Co., Ltd. is attached to the friction element with the hook side facing outward. The friction element is placed on the test piece and subjected to a five-reciprocal abrasion test with a pressure load of 9.8 N including the friction element, a stroke of 14 cm, and a speed of 60±10 reciprocations / min. Test pieces are taken from the warp and weft directions of the three-dimensional knitted fabric and measured. After the test, the wear state of the surface of the test piece is observed and the following grade is determined. The determination is made in 0.5 grade increments. Grade 5: No fluffing is observed Grade 4: Slight fluffing is observed Grade 3: Fuzzing is clearly observed, but thread breakage is not noticeable Grade 2: Fuzzing is somewhat noticeable, with thread breakage and "pulling out of threads" Grade 1: Fuzzing is significant, with severe abnormalities in appearance

[0041] (g) Taber abrasion resistance (JASO method) (grade) According to JASO M403 A method (Taber rotary abrader method), a Taber abrasion tester is used, and the test piece is abraded 1,000 times with a CS-10 abrasion wheel at a load of 500 g and a speed of 70 rpm. After the test, the abrasion state of the surface of the test piece is observed and the following grade is determined. The grade is determined in increments of 0.5 grades. Grade 5: No change in surface condition Grade 4: Slight fuzzing Grade 3: Heavy fuzzing Grade 2: Heavy fuzzing and thinning of threads Grade 1: Thread breakage occurs.

[0042] (h) Taber Abrasion Resistance (ASTM Method) (Grade) According to ASTM 3884-9 method (rotating platform double head method), a Taber abrasion tester is used, and the test piece is abraded 1000 times with a CS-10 abrasion wheel at a load of 1000 g and a speed of 72 rpm. After the test, the abrasion state of the surface of the test piece is observed, and the following grade is determined according to JASO M403 A method. The grade is determined in increments of 0.5 grades. Grade 5: No change in surface condition Grade 4: Slight fuzzing Grade 3: Heavy fuzzing Grade 2: Heavy fuzzing and thinning of threads Grade 1: Thread breakage.

[0043] (i) Touch evaluation (grade) A 15 cm square sample is collected and conditioned for 8 hours or more in a temperature- and humidity-controlled room at a temperature of 20°C and a humidity of 65%. Ten subjects are selected, and while blindfolded in the temperature- and humidity-controlled room, they touch the fabric by rubbing it up and down with four fingers excluding the thumb, and make a judgment based on the following criteria, in increments of 0.5 grades. The average score of the 10 subjects is taken as the score. Grade 5: Very comfortable Grade 4: Slightly comfortable Grade 3: Neither comfortable nor uncomfortable Grade 2: Slightly uncomfortable Grade 1: Very uncomfortable

[0044] [Example 1] Using a double Russell knitting machine equipped with six reeds, 22 gauge, and 6 mm between hooks, two reeds (L1, L2) were used to align two false twist textured yarns of 167 dtex 48 filaments polyethylene terephthalate fiber (black dope-dyed yarn) and supply them in a 1-in-1-out (L1) and 1-out-1-in (L2) arrangement, and one reed (L3) formed a shape-fixed layer. The false twisted yarn was supplied in a 1-in-1-out arrangement, and a monofilament of 110 dtex polyethylene terephthalate fiber (black spun-dyed yarn) was supplied in a 1-in-1-out (L4) arrangement from one reed (L4) forming the connecting portion. Furthermore, two reeds (L5, L6) forming the back layer knitted fabric were supplied with a false twisted yarn of 110 dtex 36 filament polyethylene terephthalate fiber (black spun-dyed yarn) in an all-in arrangement. A three-dimensional knitted fabric was knitted with the knitting structure shown below, with 35 courses / 2.54 cm on the machine. The resulting gray fabric was removed from the knitting machine, widened by 5% using a pin tenter, and dry-heat set at 180 ° C. for 1 minute with an overfeed rate of 0%, resulting in a three-dimensional knitted fabric with a finished knit density of 37 courses / inch and 24 wales / inch. (Knit structure) L1: 1011 / 1211 / 4544 / 4344 / / (1 in 1 out) L2: 4544 / 4344 / 1011 / 1211 / / (1 out 1 in) L3: 1011 / 1211 / 4544 / 4344 / / (1 in 1 out) L4: 3410 / 3245 / 2145 / 2310 / / (1 out 1 in) L5: 2210 / 0012 / / (All in) L6: 0023 / 3310 / / (All in)

[0045] Example 2 A three-dimensional knitted fabric having a finished knit density of 37 courses / inch and 24 wales / inch was obtained in the same manner as in Example 1, except that the L3 harness yarn was changed to 1 in 3 out.

[0046] Example 3 A three-dimensional knitted fabric having a finished knit density of 37 courses / inch and 24 wales / inch was obtained in the same manner as in Example 1, except that the harness yarn for L3 was changed to 2-in 1-out.

[0047] [Comparative Example 1] Using a double Russell knitting machine equipped with six reeds and a 22 gauge and 6 mm hook spacing, two 167 dtex 48 filament polyethylene terephthalate fiber (black spun-dyed yarn) false twist textured yarns were aligned and supplied from the two reeds (L1, L2) forming the surface layer knitted fabric in a 1-in-1-out (L1) and 1-out-1-in (L2) arrangement, and a 110 dtex polyethylene terephthalate fiber (black spun-dyed yarn) monofilament was supplied from the one reed (L4) forming the connecting portion in a 1-in-1-out (L4) arrangement, and further, two reeds (L5, L6) forming the back layer knitted fabric were supplied with a 110 dtex 36 filament polyethylene terephthalate fiber (black spun-dyed yarn) false twist textured yarn, both in an all-in arrangement. A three-dimensional knitted fabric was knitted with the knitting structure shown below, with 35 courses per 2.54 cm on the machine. The resulting grey fabric was removed from the knitting machine, widened by 5% using a pin tenter, and dry heat set at 180°C for 1 minute with an overfeed rate of 0%, to obtain a three-dimensional knitted fabric with a finished knit density of 37 courses / inch and 24 wales / inch. (Knit structure) L1: 1011 / 1222 / 4544 / 4333 / / (1 in 1 out) L2: 4544 / 4333 / 1011 / 1222 / / (1 out 1 in) L3: No yarn supply L4: 3410 / 3245 / 2145 / 2310 / / (1 in 1 out) L5: 1110 / 1112 / / (all in) L6: 1123 / 2210 / / (all in)

[0048] [Comparative Example 2] Using a double Russell knitting machine equipped with six reeds, 22 gauge, and 1.8 mm between hooks, false-twisted yarn of 84 dtex 36 filament polyethylene terephthalate fiber (black dope-dyed yarn) was supplied from two reeds (L1, L2) in a 3-in 1-out (L1, L2) arrangement, and false-twisted yarn of 84 dtex 36 filament polyethylene terephthalate fiber (black dope-dyed yarn) was supplied from one reed (L3) that forms a shape-fixed layer. The yarns were supplied in an all-in arrangement, and a false-twisted yarn of 33 dtex 12 filament polyethylene terephthalate fiber (black spun-dyed yarn) was supplied in an all-in arrangement from one reed (L4) forming the connecting portion. Furthermore, a false-twisted yarn of 84 tex 36 filament polyethylene terephthalate fiber (black spun-dyed yarn) was supplied in an all-in arrangement from two reeds (L5, L6) forming the back layer knitted fabric. A three-dimensional knitted fabric was knitted with the knitting structure shown below, with 32 courses / 2.54 cm on the machine. The resulting gray knitted fabric was removed from the knitting machine, widened by 5% using a pin tenter, and dry-heat set at 180 ° C. for 1 minute with an overfeed rate of 0%, resulting in a three-dimensional knitted fabric with a finished knit density of 34 courses / inch and 24 wales / inch. (Knit structure) L1: 0000 / 0000 / 0100 / 0100 / / (3 in 1 out) L2: 0100 / 0100 / 0000 / 0000 / / (3 in 1 out) L3: 3433 / 1011 / / (All in) L4: 0112 / 2110 / / (All in) L5: 0111 / 1000 / / (All in) L6: 1011 / 3433 / / (All in)

[0049] [Comparative Example 3] A double Russell knitting machine with a 9-gauge and 12 mm hook interval equipped with six reeds was used. Crimped yarn of 833 dtex 192 filament polyethylene terephthalate fiber (black spun-dyed yarn) was supplied from two reeds (L1, L2) in an arrangement of 1 in 1 out (L1) and 1 out 1 in (L2). False twisted yarn of 250 dtex 72 filament polyethylene terephthalate fiber (black spun-dyed yarn) was supplied from one reed (L3) that forms the shape-fixed layer. The yarns were fed in an all-in arrangement, and a monofilament of 667 dtex polyethylene terephthalate fiber (black spun-dyed yarn) was fed in an all-in arrangement (L4) from one reed (L4) forming the connecting portion. Furthermore, crimped yarn of 833 dtex 192 filament polyethylene terephthalate fiber (black spun-dyed yarn) was fed in a 1-in-1-out (L5) and 1-out-1-in (L6) arrangement from two reeds (L5, L6) forming the knitted fabric of the back layer. A three-dimensional knitted fabric was knitted with the knitting structure shown below, with 11 courses / 2.54 cm on the machine. The obtained knitted fabric was removed from the knitting machine, widened by 5% using a pin tenter, and dry-heat set at 180 ° C. for 1 minute with an overfeed rate of 0%, to obtain a three-dimensional knitted fabric with a finished knit density of 13 courses / inch and 11 wales / inch. (Knit structure) L1: 1011 / 1211 / 1011 / 2322 / 2122 / 2322 / / (1 in 1 out) L2: 2322 / 2122 / 2322 / 1011 / 1211 / 1011 / / (1 out 1 in) L3: 1011 / / (all in) L4: 2110 / 1223 / / (all in) L5: 1011 / 1211 / 1011 / 2322 / 2122 / 2322 / / (1 in 1 out) L6: 2322 / 2122 / 2322 / 1011 / 1211 / 1011 / / (1 out 1 in)

[0050] [Comparative Example 4] Using a double Russell knitting machine equipped with six reeds, 18 gauge, and a hook interval of 15 mm, false-twisted yarn of 222 dtex 60 filament polyethylene terephthalate fiber (black spun-dyed yarn) was supplied from two reeds (L1, L2) in an arrangement of 1 in 1 out (L1) and 1 out 1 in (L2), and false-twisted yarn of 110 dtex 36 filament polyethylene terephthalate fiber (black spun-dyed yarn) was supplied from one reed (L3) that forms the shape-fixed layer. The fibers were fed in an all-in arrangement, and a monofilament of 333 dtex polyethylene terephthalate fiber (black spun-dyed yarn) was fed in an all-in arrangement (L4) from one reed (L4) forming the connecting portion. Furthermore, crimped yarn of 222 dtex 60 filament polyethylene terephthalate fiber (black spun-dyed yarn) was fed in a 1-in-1-out (L5) and 1-out-1-in (L6) arrangement from two reeds (L5, L6) forming the knitted fabric of the back layer. A three-dimensional knitted fabric was knitted with the knitting structure shown below, with 24 courses / 2.54 cm on the machine. The obtained gray fabric was removed from the knitting machine, widened by 5% using a pin tenter, and dry-heat set at 180 ° C. for 1 minute with an overfeed rate of 0%, to obtain a three-dimensional knitted fabric with a finished knit density of 26 courses / inch and 20 wales / inch. L1: 1011 / 1211 / 1011 / 2322 / 2122 / 2322 / / (1 in 1 out) L2: 2322 / 2122 / 2322 / 1011 / 1211 / 1011 / / (1 out 1 in) L3: 1211 / 1011 / / (all in) L4: 4554 / 3210 / 0123 / / (all in) L5: 1000 / 0111 / / (1 in 1 out) L6: 3433 / 1011 / / (1 out 1 in)

[0051] The results of the above examples and comparative examples are shown in Table 1 below.

[0052]

[0053] As shown in Table 1, the three-dimensional knit fabrics of Examples 1 to 3 had a good feel, good ASTM-standard Taber abrasion resistance and scratch resistance, and little stitch collapse under tensile load. In contrast, Comparative Example 1 did not have a shape-fixing layer, and Comparative Example 2 had a ratio (A) of the number of knit loops in the surface layer to the number of knit loops in the shape-fixing layer of 75%, resulting in poor ASTM-standard Taber abrasion resistance and significant stitch collapse under tensile load. Furthermore, Comparative Example 3 had a low knit density after finishing and used excessively thick yarn to maintain strength, resulting in good ASTM-standard Taber abrasion resistance and scratch resistance, but an unpleasant feel and significant stitch collapse under tensile load. Comparative Example 4 had a low knit density after finishing and a good feel, but poor ASTM-standard Taber abrasion resistance and scratch resistance, and significant stitch collapse under tensile load.

[0054] The three-dimensional knitted fabric of the present invention suppresses stitch collapse due to excessive elongation when a tensile load is applied, such as when a seat is installed, and has Taber abrasion resistance and scratch resistance according to the ASTM method, making it suitable for use as an interior material for vehicles.

Claims

1. A three-dimensional knitted fabric comprising a surface knitted fabric, a back knitted fabric, and a connecting yarn connecting the surface knitted fabric and the back knitted fabric, wherein the surface knitted fabric comprises a surface layer located on the outermost side of the three-dimensional knitted fabric, and a shape-fixing layer located inside the three-dimensional knitted fabric relative to the surface layer and including knit loops formed at the same positions as the knit loops included in the surface layer, wherein the knit density of the surface knitted fabric after finishing is 30 courses / inch or more and 64 courses / inch or less, and the ratio (A) of the number of knit loops included in the surface layer to the number of knit loops included in the shape-fixing layer is more than 100% and 400% or less.

2. The three-dimensional knit fabric according to claim 1, wherein the ratio (A) of the number of knit loops contained in the surface layer to the number of knit loops contained in the shape-fixing layer is 150% or more.

3. A three-dimensional knitted fabric according to claim 1 or 2, wherein in the shape-fixing layer, knit loops that are spaced apart by one wale or more are connected by sinker loops.

4. The three-dimensional knitted fabric according to claim 1 or 2, wherein the shape-fixing layer is a Denbigh knit.

5. A three-dimensional knitted fabric as described in claim 1 or 2, wherein the total fineness of the yarns forming all the knit loops included in the surface knitted fabric is 100 dtex or more and 1000 dtex or less.

6. A three-dimensional knitted fabric as described in claim 5, wherein the total fineness of the yarns forming all the knit loops included in the knitted fabric of the surface layer is 250 dtex or more and 1000 dtex or less.

7. A three-dimensional knitted fabric as described in claim 1 or 2, wherein, among the knit loops included in the surface knitted fabric, for all knit loops including connecting yarns, the value obtained by dividing the fineness of the yarns other than the connecting yarns forming each knit loop by the fineness of the connecting yarn is 2.8 or more.

8. A three-dimensional knitted fabric as described in claim 7, wherein, among the knit loops included in the surface knitted fabric, for all knit loops including connecting yarns, the value obtained by dividing the fineness of the yarns other than the connecting yarn forming each knit loop by the fineness of the connecting yarn is 3.0 or more.

9. The three-dimensional knitted fabric according to claim 1 or 2, wherein the stitch density of the surface knitted fabric calculated by the following formula: Stitch density M = N x √D {where N is the number of stitches (stitches) of the surface knitted fabric per 2.54 cm square, and D is the total fineness (dtex) of the fibers forming one stitch of the surface knitted fabric} is 11,500 or more and 20,000 or less.

10. A three-dimensional knitted fabric according to claim 1 or 2, wherein the constant load set rate when a tensile load of 10 kg is applied in the warp direction of the three-dimensional knitted fabric for 10 minutes is 3% or less.

11. The air permeability of the three-dimensional knitted fabric from the connecting layer to the outer knitted fabric is 33 cc / cm ２ The three-dimensional knitted fabric according to claim 1 or 2, wherein the knitting time is 1 / sec or more.

12. The three-dimensional knitted fabric according to claim 1 or 2, wherein at least one of the knitted fabric of the front layer and the knitted fabric of the back layer contains a heat-sealable yarn.

13. A vehicle interior material comprising the three-dimensional knitted fabric according to claim 1 or 2, wherein the knitted fabric of the surface layer and the knitted fabric of the back layer is positioned on the interior side of the vehicle.

14. The vehicle interior material according to claim 13, which is a seat covering material.

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