JPWO2006106974A1 - Fabric having sound absorption - Google Patents

Abstract

The present invention provides a lightweight and sound-absorbing fabric capable of obtaining sufficient sound-absorbing performance, and is a three-dimensional structure in which two ground structures (1) and (2) are connected by connecting yarns, and the incidence of sound. The surface texture (1) has a mesh-shaped opening (4), and the curvature (1 / R) of the non-opening (5) of the texture is 0 when the radius of curvature is Rmm. It is formed in a dome shape of 1 to 0.7, the height from the base to the top of the non-opening portion (5) is 1.5 to 5.0 mm, and the DV value obtained by the following formula [1] is The insertion thread (6) is knitted and locked inside the ground structure (2) on the non-incident surface side of the sound. DV = (4.2 × π × A × W × c ′) / c [1] A: Non-opening height (mm) W: Non-opening in the course direction Length (mm) c '... Number of loops for one repeat in the well direction of the non-opening part c ... Course density at the finish of the fabric having sound absorption

Description

  The present invention relates to a sound-absorbing fabric. Specifically, it is a three-dimensional structure formed by connecting two ground structures with connecting yarns, the sound incident surface has a mesh-like opening, and the insertion yarn is knitted and locked inside the sound non-incident surface. The present invention relates to a fabric having sound absorption.

  As a sound-absorbing material, it is generally used for a building, a vehicle, a transportation device, or the like, in which a porous material such as glass wool, urethane foam, felt, polyethylene foam, or synthetic fiber nonwoven fabric is bonded to a surface material. And Patent Document 2.

However, the sound absorbing property of the porous material is lowered by the adhesive used for bonding the surface material, and the surface material and the porous material are reduced if the amount of the adhesive used is reduced in order to suppress the deterioration of the sound absorbing performance. There is a problem that it becomes easy to peel. In addition, bonding a surface material to such a porous material has poor work efficiency and has a problem of cost increase due to process load.
As an improvement of these problems, Patent Document 3 discloses a sound-absorbing interior material using a woven or knitted fabric made of two layers of upper and lower layers and a connecting yarn. However, the sound absorption effect is not sufficient because there is no opening in the fabric. Therefore, it is necessary to increase the thickness of the fabric considerably in order to improve the sound absorption effect. For this reason, it is not realistic to increase the thickness without limitation in accordance with the sound absorption performance required when using it as an interior material, and further, increasing the thickness makes the fabric weight heavy, resulting in poor workability and increased costs. There is.
Japanese Utility Model Publication No.59-1793 Japanese Unexamined Patent Publication No. 1-150533 Japanese Utility Model Publication No. 4-53087

  The present invention solves the above-described problems, and provides a fabric that does not require a process such as bonding to a skin material, and is lightweight and capable of obtaining sufficient sound absorption performance.

  The present invention for solving the above problems is as follows.

  (1) A three-dimensional structure formed by connecting two ground structures with a connecting thread, the ground structure on the sound incident surface side having a mesh-like opening and a non-opening, The opening is formed in a dome shape having a curvature (1 / R) of 0.1 to 0.7 when the radius of curvature is Rmm, and the height from the base to the apex of the non-opening is 1. 5 to 5.0 mm, a DV value obtained by the following formula [1] is 5 to 120, and the insertion yarn is knitted and locked inside the ground structure on the non-incident surface side of the sound. It is a fabric having properties.

DV = (4.2 × π × A × W × c ′) / c [1]
A: Height of non-opening (mm)
W ... Length of the non-opening in the course direction (mm)
c '... Number of loops for one repeat of the non-opening in the well direction (pieces)
c ... Course density at the time of finishing the fabric having sound absorption (number of courses / 吋)
(2) The non-opening portion (dome-shaped portion) of the ground structure on the sound incident surface side has 6 to 14 loops for one repeat in the course direction and 4 to 24 loops for one repeat in the well direction. The fabric having sound absorption as described in (1).

  (3) The cloth having sound absorbing properties according to (1), wherein the insertion rate of the insertion yarn that is knitted and locked inside the ground structure on the non-incident surface side of the sound is 25 to 100%. is there.

  (4) The fabric having sound absorbing properties according to (1), wherein the thickness of the ground yarn forming the ground structure on the sound incident surface side is 167 to 550 dtex.

  (5) The fabric having sound absorbing properties according to (1), wherein the thickness of the insertion yarn knitted and locked inside the ground structure on the non-incident surface side of the sound is 167 to 1400 dtex.

  (6) The fabric having sound absorbing properties according to (1), wherein the fabric has a thickness of 2 to 20 mm.

  The fabric having sound absorption of the present invention is provided with a non-opening portion and an opening made of a dome-shaped portion in the ground structure on the sound incident surface side of the three-dimensional structure, and on the inner side of the sound tissue on the non-incident surface side of the sound. By knitting and locking the insertion yarn, sufficient sound absorption performance can be obtained even if the fabric with sound absorption is lightweight, and it can be used alone as a sound absorption material without the need for steps such as bonding with other skin materials. Yes, it can be preferably used for interior materials of buildings and vehicles.

  Hereinafter, embodiments of the present invention will be described in detail.

  As the three-dimensional structure used in the present invention, a double raschel knitted fabric is preferably used in that the thickness of the three-dimensional structure can be easily obtained.

  The sound-absorbing fabric according to the present invention is a three-dimensional structure in which two ground structures 1 and 2 are connected by a connecting thread 3 as shown in FIGS. 2, 3A, and 3B. Therefore, the ground structure 1 on the sound incident surface side has a mesh-shaped opening 4 and a dome-shaped non-opening 5 having a curvature of 0.1 to 0.7, and the base of the non-opening 5 The height from the top to the top (A in FIG. 6) is 1.5 to 5.0 mm, the DV value obtained by the formula [1] described later is 5 to 120, and no sound is incident. The insertion yarn 6 is knitted and locked inside the surface side ground structure 2.

  For example, in a three-dimensional structure by double raschel knitting, for the ground yarn forming the ground structure 1 on the sound incident surface side, an arbitrary number of yarn removals (among the yarn introduction guides of the ground yarn corresponding to each knitting needle, For an arbitrary number of guides at regular intervals, the ground yarn is knitted without introducing the yarn), and the ground yarn is alternately swung to the left and right with the same number of wells as the number of yarns removed. A mesh-like opening 4 is provided in the ground texture 1 on the surface side. Thereby, compared with the conventional sound-absorbing material using a three-dimensional structure without an opening, incident sound is more likely to enter the three-dimensional structure, so that the sound absorption performance is significantly improved. The aperture ratio is not particularly limited, but preferably has an opening 4 of 10% or more with respect to the ground plane in order to obtain a sufficient sound absorption effect. When the aperture ratio is less than 10%, the incident sound is likely to be reflected by the sound incident surface side texture of the three-dimensional structure, so that the sound absorption performance may be deteriorated. When the aperture ratio exceeds 50%, the reflected sound of the sound once incident on the inside of the three-dimensional structure is likely to diffuse from the opening to the outside, so that there is a possibility that the sound absorbing performance is deteriorated. Therefore, the range of the aperture ratio of 10 to 40% is more preferable in terms of sound absorption performance.

  The aperture ratio of the present invention is as follows. The sound incident surface side texture of the three-dimensional structure on the 1st and 4th sides is read by a personal computer with a scanner, the aperture and other portions are binarized, and the ratio of the apertures on the 1st and 4th sides is determined. Asked.

  In the three-dimensional structure, the non-opening portion 5 in the ground structure 1 on the sound incident surface side is formed in a dome shape by swinging the ground yarn forming the ground structure 1 on the sound incident surface side. By adopting such a dome shape, the surface area of the sound incident surface side ground tissue is increased and the sound absorbing performance is improved. Also, as shown in FIG. 4, when the sound once incident on the inside of the three-dimensional structure is reflected on the ground structure 1 on the surface side, the reflected sound is difficult to diffuse outside the three-dimensional structure, and the incident sound is not Since the number of times of reflection and reciprocation within the three-dimensional structure increases, the fibers are vibrated and sound waves are attenuated, so that sound absorption is promoted. At this time, the non-opening 5 has a curvature (1 / R) of 0.1 to 0.7 and a height of the non-opening 5 of 1. 5 to 5.0 mm, and the DV value is 5 to 120.

  As shown in FIG. 5, the radius of curvature R of the non-opening 5 is derived from the ground tissue forming the dome-shaped non-opening, and the curvature is 1 / R.

  As shown in FIG. 6, the height A of the non-opening 5 is obtained by subtracting the thickness C from the thickness B of the entire fabric to the bottom of the non-opening 5.

Non-opening height (mm) A = B-C
The DV value is obtained by calculating the approximate volume of the non-opening portion from the equation (V = 4/3 · πab ² ) for determining the volume of the elliptic sphere when the non-opening portion 5 is viewed as a semi-elliptical sphere. is there.

  Therefore, the DV value of the non-opening is obtained as follows.

DV value = 4/3 × π × (length of non-opening in the well direction / 2) × (height of non-opening) × (length of non-opening in the course direction / 2) × 1/2
Further, the length of the non-opening in the well direction, the height of the non-opening, and the length of the non-opening in the course direction are obtained as follows.

Length in the well direction of the non-opening (mm) = Number of loops c ′ (pieces) for one repeat in the well direction of the non-opening / Course density c (number of courses / 吋) at the finish of the sound-absorbing fabric × 2.54 × 10
Non-opening height A (mm) = measured value (measures the height of any three points from the electron micrograph and calculates the average value)
Length W (mm) of the non-opening in the course direction = actual value (measured from the electron micrograph, the length of the bottom of the cross-section in the course direction at the top of the non-opening at any three points is calculated)
A summary of the above is the following formula [1].

DV = (4.2 × π × A × W × c ′) / c [1]
When the curvature is 0.1 or less, the height is less than 1.5 mm, and the DV value is less than 5, a dome shape having a clear curvature cannot be obtained, so that a sufficient sound absorbing effect may not be obtained.

  Further, the non-opening portion 5 of the ground texture on the sound incident surface side has 6 to 14 loops in the course direction (w ′ in FIG. 3B) and 1 repeat in the well direction (c ′ in FIG. 3A). It is preferably formed of 4 to 24 loops. If the number of loops is less than 6 loops in the course direction or less than 4 loops in the well direction, it is difficult to obtain a dome shape. If the number of loops is 15 loops in the course direction or 25 loops in the well direction, the opening is small. Therefore, there is a possibility that a sufficient sound absorbing effect cannot be obtained.

  In the present invention, the ground yarn constituting the ground structure on the sound incident surface side can be appropriately selected from known synthetic fibers and natural fibers, but from the viewpoint of durability, synthetic fibers, particularly polyester is preferable. Further, as the yarn type, it is preferable to use a yarn having a small apparent density such as a spun yarn or a processed yarn. By selecting such a thread, the acoustic impedance of the ground tissue surface is brought close to the acoustic impedance of the air, and the incident sound can more easily enter the inside.

  The acoustic impedance is a value specific to the medium propagating the sound and is expressed by the density of the medium × the speed of sound. The medium having a larger difference in the acoustic impedance has a higher reflectance of the incident sound, and the smaller the difference in the acoustic impedance is. Incident sound can easily enter the medium and a sound absorbing effect can be obtained. Therefore, if a yarn having a low apparent density such as a spun yarn or a processed yarn is used as the yarn constituting the ground structure on the incident surface side of the fabric of the present invention, the acoustic impedance becomes the acoustic impedance of the sound source medium (air). The incident sound becomes close to the inside of the medium and the sound absorption effect is improved. It is also preferable to use a yarn having a large surface area relative to the volume, such as a multifilament yarn, that is, a yarn having a low apparent density, because the effect of absorbing incident sound is enhanced. Further, the thickness of the yarn constituting the ground structure is preferably in the range of 167 to 550 dtex. When the thickness of the yarn is less than 167 dtex, the thickness of the overlap of the yarns forming the non-opening portion of the ground texture becomes thin, and there is a possibility that a dome shape sufficient for sound absorption performance cannot be obtained. In addition, when a thread thicker than 550 dtex is used, there is a concern that the basis weight increases and the cost increases.

  The ground yarn constituting the ground structure on the non-incident surface side of the sound can be appropriately selected from known synthetic fibers and natural fibers. From the viewpoint of strength and durability, synthetic fibers, especially polyester fibers are used. It is preferable to use it. The fineness of the yarn constituting the ground texture is 84 to 330 dtex, preferably 110 to 220 dtex. It is preferable to use spun yarn, processed yarn, multifilament yarn, etc. as the yarn type. If it is less than 110 dtex, there is a possibility that the sound absorption may be lowered because the density on the non-incident surface side of the sound is not sufficiently increased. In addition, when a thread thicker than 220 dtex is used, there is a concern that the basis weight increases and the cost increases.

  The density of the texture on the non-incident surface side of the sound when finished is in the range of 30-60 course / 吋, 18-40 well / 吋, preferably 33-50 course / 吋, 20-36 well / 吋. Preferably there is. If it is smaller than this range, the density of the ground structure is small and a sufficient sound absorption effect cannot be obtained. If it is larger than this range, the basis weight of the ground structure is large and the cost is increased.

  In addition, the incident sound is incident from the side of the ground structure having an opening (low apparent density) to the sound-absorbing fabric, and the void portion where the connecting yarn exists, the ground structure having no opening (high apparent density). Proceed in order. In this way, by increasing the density of the fabric within the above range as the density of the fabric is increased from the sound incident surface side to the non-incident surface side, sound reflection is reduced and a high sound absorption effect is obtained. It is done.

  The sound-absorbing fabric of the present invention preferably satisfies the following formula in the cross section in the well direction and the course direction including the apex of the non-opening.

D>E> F, D ′> E ′> F ′
D: Distance between vertices of non-openings adjacent in the well direction E: Distance between bases of non-openings adjacent in the well direction F: Connection thread of non-openings adjacent in the well direction Distance between locks that are knitted and locked to the non-incident surface texture of sound D '... Distance between vertices of non-openings adjacent to the course direction E' ... of non-openings adjacent to the course direction Distance between bases F '... Distance between the engagements where the connecting yarns of the non-openings adjacent in the course direction are knitted and locked to the sound non-incident surface texture. And the gap formed by the opening becomes a so-called taper shape that decreases as it goes from the sound incident surface side to the sound non-incident surface side, and the incident sound is repeatedly reflected by the taper portion, and the sound is changed into thermal energy. A high sound absorption effect can be obtained.

  Furthermore, in the sound absorbing fabric of the present invention, as shown in FIGS. 2, 3A, and 3B, the insertion yarn 6 is knitted and locked inside the ground structure 2 on the non-incident surface side of the sound of the three-dimensional structure. Therefore, the density on the non-incident surface side of the sound is increased, and the fabric has a high sound absorption effect.

  The knitting lock referred to in the present invention is, for example, when the insertion yarn is inserted in the well direction (knitting direction) in a double raschel knitted fabric, and the insertion yarn is formed on the ground structure on the non-incident surface side of the sound at an arbitrary number of course intervals. In the case of inserting the insertion thread in the course direction (width direction), the insertion thread for swinging the arbitrary number of wells is inserted by the ground structure inside the ground structure on the non-incident surface side of the sound. It means a pressed state.

  At this time, the insertion yarn can be appropriately selected from known synthetic fibers and natural fibers, but from the viewpoint of durability, synthetic fibers, particularly polyester is preferable. As the yarn type, it is preferable to use a yarn having a small apparent density, such as a spun yarn, a processed yarn, or a multifilament yarn. By selecting such a yarn, the sound absorption performance inside the fabric can be improved. The thickness of the thread used for the insertion thread is preferably in the range of 167 to 1400 dtex. If the frequency is less than 167 dtex, the density of the sound non-incident surface side is not sufficiently increased, so that there is a possibility that sound absorption may be reduced. In addition, when a thread thicker than 1400 dtex is used, there is a concern that the basis weight increases and the cost increases.

  Further, the insertion rate of the sound of the insertion thread with respect to the course density or well density of the ground structure on the non-incident surface side is 25 to 25 (assuming that the insertion is performed for each course or each well). 100% is preferred. If it is less than 25%, the density on the non-incident surface side of the sound is not sufficiently increased, so that there is a possibility that the sound absorbing effect by the insertion yarn cannot be sufficiently obtained.

  The calculation method of the insertion rate of the insertion thread is shown below.

(1) When inserting in the well direction (knitting direction) Insertion rate (%) = X / c x 100
X: Number of inserted yarns (1 piece / 吋) existing in 1 cm of the course direction when finishing a fabric having sound absorption
c: Course density at the time of finishing a fabric having sound absorption (number of courses / 吋)
(2) When inserting in the course direction (width direction) Insertion rate (%) = Y / (c x w) x 100
Y: Number of loops in which the inserted yarn is knitted and locked in the first and fourth sides of the ground structure (pieces / 吋² )
c: Course density at the time of finishing a fabric having sound absorption (number of courses / 音)
w: Well density (number of wells / 吋) at the finish of the fabric having sound absorption
The connecting yarn of the present invention can be appropriately selected from known synthetic fibers and natural fibers. From the viewpoint of durability, synthetic fibers, particularly polyesters are preferable. As the yarn type, it is preferable to use a monofilament yarn, a multifilament yarn, a spun yarn, and a processed yarn as appropriate from the viewpoint of sound absorption. By using monofilament yarn, the thickness of the three-dimensional structure and the gaps in the connecting part of the ground structure can be maintained, and the number of times the incident sound is reflected and reciprocated inside the three-dimensional structure increases, causing the fibers to vibrate and the sound waves to attenuate. Absorption is promoted. Further, by appropriately blending multifilament yarns, spun yarns, and processed yarns having a larger surface area than that of monofilaments having the same fineness, that is, an apparent density, incident sound is easily absorbed inside the sound absorbing material and sound absorbing properties are improved.

  At this time, the blending ratio of the monofilament yarn in the total weight of the connecting yarn is preferably 40% or more, particularly 50% or more. If the blending ratio is less than 40%, the thickness of the three-dimensional structure and the gaps in the connected portions of the ground texture cannot be maintained, so that sufficient sound absorption may not be obtained.

  The fineness of the connecting yarn is preferably in the range of 22 to 330 dtex. If it is thinner than 22 dtex, there is a possibility that the thickness and voids of the three-dimensional structure cannot be maintained, and if it is thicker than 330 dtex, the connecting yarn may jump out of the ground structure.

  In the case of multifilament yarn, the single yarn fineness is preferably 2 dtex or more. When the single yarn fineness is thinner than 2 dtex, there is a possibility that the thickness and voids of the three-dimensional structure cannot be maintained.

  It is preferable that the thickness including the two ground structures of the sound-absorbing fabric is in the range of 2 to 20 mm. If it is less than 2 mm, it is difficult to form a dome-shaped non-opening on the sound incident surface side, and there is a possibility that a sufficient sound absorbing effect cannot be obtained. If it is larger than 20 mm, sound absorption performance can be obtained, but there is a problem that the basis weight is increased and the cost is increased.

Further, the apparent density of the fabric having sound absorption calculated by the following formula is preferably 0.3 g / cm ³ or less. If it is larger than 0.3 g / cm ³ , a sufficient gap cannot be obtained inside the sound absorbing material, and there is a possibility that the sound absorbing effect due to irregular reflection of the incident sound inside cannot be obtained.

Apparent density = Z / (1000 x B)
Z: Weight of 1 meter square fabric (g) having sound absorption
B: Thickness (mm) of fabric having sound absorption

(Example 1)
Using Meyer's knitting machine (RD6DPLM-77E-22G), as shown in FIG. 7, knitting the back side fabric using a thread of 110 dtex / 48f on heel L-1: L-2,筬 L-5: Knitting a surface side fabric with an opening using 167 dtex / 48f yarn on L-6, and using 33 dtex monofilament yarn on the connecting yarn of 筬 L-3 Connected, using 167 dtex / 48f double thread 1-in-2-out as an insertion thread to the heel L-4, knitting in the ground structure once every 5 courses in the well direction from the inside of the back-side ground structure Stopped and inserted.

  The surface-side ground texture yarn (ground yarn) is swung in the course direction by three stitches (the ground yarn moves in the weft direction (underlap) across the three stitches) in the well direction. It knit | knitted so that it might move to the course direction for 3 stitches by turns right and left alternately at 6 course intervals, and an opening part may be formed.

  The obtained knitted fabric was preset at 190 ° C. for 1 minute, dyed at 130 ° C., dried, and finished and set at 150 ° C. for 1 minute. Finished 36 courses / 吋: 23 wells / 吋 with a thickness of 3.0 mm A three-dimensional structure was created. Details are shown in Table 1.

(Example 2)
Using Meyer's knitting machine (RD6DPLM-77E-22G), as shown in FIG. 8, knitting the back side fabric using 110dtex / 48f yarn on heel L-1: L-2,筬 L-5: Knitting a surface side fabric with an opening using 167 dtex / 48f twin yarn on L-6, and front and back fabric using 33 dtex monofilament yarn for connecting yarn of 筬 L-3 , Using 167 dtex / 48f of double thread as an insertion thread to the heel L-4, 2 in 1 out, knitting to the ground structure at intervals of 5 courses from the inside of the back side ground structure to the well direction Locked and inserted.

  The yarn of the surface side ground texture was knitted so that the swinging width was 6 stitches in the course direction, and the left and right alternately moved 6 courses in the course direction in the well direction in the course direction to form an opening. .

  The resulting knitted fabric was preset at 190 ° C. for 1 minute, dyed at 130 ° C., dried, and finished and set at 150 ° C. for 1 minute. Finished 36 courses / 吋: 23 wells / 吋 with a thickness of 4.0 mm A three-dimensional structure was created. Details are shown in Table 1.

(Example 3)
Using Meyer's knitting machine (RD6DPLM-77E-22G), as shown in FIG. 9, knitting the back side fabric using 110dtex / 48f processed yarn on heel L-1: L-2筬 L-5: Knitting a surface side fabric with an opening using 167 dtex / 48f yarn on L-6, and front and back fabric using 33 dtex monofilament yarn for connecting yarn of 筬 L-3 , Using 167 dtex / 48f of double thread as 1-in-2-out as an insertion thread to the heel L-4, knitting to the ground structure at intervals of 11 courses in the well direction from the inside of the back side ground structure Locked.

  The yarn of the surface side ground texture was knitted so that the swinging width was swung by 3 needles in the course direction, and moved to the course direction by 3 stitches alternately in the left and right directions at 12 course intervals in the well direction to form openings. .

  The resulting knitted fabric was preset at 190 ° C. for 1 minute, dyed at 130 ° C., dried, and finished and set at 150 ° C. for 1 minute. Finished 36 courses / 吋: 23 wells / 吋 with a thickness of 4.0 mm A three-dimensional structure was created. Details are shown in Table 1.

Example 4
Using Meyer's knitting machine (RD6DPLM-77E-22G), as shown in FIG. 10, knitting the back side fabric using 110dtex / 48f yarn on heel L-1: L-2,筬 L-5: knitting a surface side ground texture with an opening using 167 dtex / 48f yarn on L-6, 33 dtex monofilament yarn 7 in 3 out on connecting yarn of 筬 L-3, 33 dtex / 6f polyester processed yarn is used in 3 in 7 out to connect the front and back fabric structures, and 167dtex / 48f double yarn is used in 1 in 2 out as an insertion thread to the heel L-4, inside the back side fabric The knitting was locked to the ground texture at intervals of once every 5 courses in the well direction.

  The yarn of the surface side ground texture was knitted so as to form an opening by swinging three stitches in the course direction in the course direction and moving in the course direction by three stitches alternately in the well direction at intervals of 6 courses. .

  The obtained knitted fabric was preset at 190 ° C. for 1 minute, dyed at 130 ° C., dried, and finished and set at 150 ° C. for 1 minute. Finished 36 courses / 吋: 23 wells / 吋 with a thickness of 3.0 mm A three-dimensional structure was created. Details are shown in Table 1.

(Example 5)
Using Meyer's knitting machine (RD6DPLM-77E-22G), as shown in Fig. 11, 167 dtex / 48f yarn on 筬 L-1 and 110 dtex / 48f yarn on 筬 L-4, 1 in 2 out Used to organize the back side ground structure. A thread of 1200 dtex / 210f was used as an insertion thread for the heel L-2, and inserted and locked continuously every course inside the back side ground texture by the thread of L-4.筬 L-5: Knitting a surface side fabric with an opening using 167 dtex / 48f yarn on L-6, and using a 33 dtex monofilament yarn on the connecting yarn of 筬 L-3, Were organized to connect.

  The yarn of the surface side texture was knitted so that the swing width was swung by three needles in the course direction and moved in the course direction by three needles alternately in the well direction at intervals of six courses to form the opening.

  The obtained knitted fabric was preset at 190 ° C. for 1 minute, dyed at 130 ° C., dried, and finished and set at 150 ° C. for 1 minute. Finished 36 courses / 吋: 23 wells / 吋 with a thickness of 3.0 mm A three-dimensional structure was created. Details are shown in Table 1.

(Comparative Example 1)
Using a Mayer knitting machine (RD6DPLM-77E-22G), as shown in FIG. 12, knitting the back surface fabric using 167dtex / 48f yarn on heel L-1: L-2, L-5: Knit the surface opening ground structure using 110 dtex / 48f yarn in L-6, and connect the front and back fabric structures using 33 dtex monofilament yarn to the connecting yarn of L-3 Organized.

  The yarn of the surface side ground texture was knitted so as to form an opening by swinging three stitches in the course direction in the course direction and moving in the course direction by three stitches alternately in the well direction at intervals of 6 courses. .

  The obtained knitted fabric was preset at 190 ° C. for 1 minute, dyed at 130 ° C., dried, and finished and set at 150 ° C. for 1 minute. Finished 36 courses / 吋: 23 wells / 吋 with a thickness of 3.0 mm A three-dimensional structure was created. Details are shown in Table 1.

(Comparative Example 2)
Using a Mayer knitting machine (RD6DPLM-77E-22G), as shown in FIG. 13, knitting the back surface fabric using 167dtex / 48f yarn on heel L-1: L-2, L-5: Knit the surface opening ground structure using 167 dtex / 48f yarn on L-6, and connect the front and back fabric structure using 33 dtex monofilament yarn to the connecting yarn of L-3 Organized.

  The yarn of the surface side ground texture was knitted so that the swinging width was swung by one needle in the course direction, and moved in the course direction by one stitch alternately in the well direction at intervals of 6 courses to form the opening. .

  The obtained knitted fabric was preset at 190 ° C. for 1 minute, dyed at 130 ° C., dried, and finished and set at 150 ° C. for 1 minute. Finished 36 courses / 吋: 23 wells / 吋 with a thickness of 3.0 mm A three-dimensional structure was created. Details are shown in Table 1.

(Comparative Example 3)
Using (RD6DPLM-77E-22G) manufactured by Meyer, knitting the back side fabric using 167dtex / 48f yarn on 筬 L-1: L-2 as shown in FIG. -5: The surface side ground texture was knitted using a thread of 167 dtex / 48f for L-6, and the front and back ground structures were knitted using a 33 dtex monofilament thread for the connecting thread of 筬 L-3. .

  The obtained knitted fabric was preset at 190 ° C. for 1 minute, dyed at 130 ° C., dried, and finished and set at 150 ° C. for 1 minute. Finished 36 courses / 吋: 23 wells / 吋 with a thickness of 3.0 mm A three-dimensional structure was created. Details are shown in Table 1.

(Comparative Example 4)
Using Meyer's knitting machine (RD6DPLM-77E-22G), knitting the back surface fabric using 167dtex / 48f yarn on heel L-1: L-2 according to the organization chart of FIG.筬 L-5: Knitting the surface opening fabric using 167 dtex / 48f twin yarn on L-6, and using 33 dtex monofilament yarn on the connecting yarn of 筬 L-3 Organized to connect.

  The yarn of the surface side ground texture was knitted so that the swinging width was 6 stitches in the course direction, and moved in the course direction by 6 needles alternately left and right at 18 course intervals in the well direction to form openings. .

  The obtained knitted fabric was preset at 190 ° C. for 1 minute, dyed at 130 ° C., dried, and finished and set at 150 ° C. for 1 minute. A three-dimensional structure was created. Details are shown in Table 1.

(Comparative Example 5)
Using Meyer's knitting machine (RD6DPLM-77E-22G), knitting the back surface fabric using 167dtex / 48f yarn on heel L-1: L-2 according to the organization chart of FIG.筬 L-5: Knitting the surface opening fabric using 167 dtex / 48f twin yarn on L-6, and using 33 dtex monofilament yarn on the connecting yarn of 筬 L-3 Organized to connect.

  The yarn of the surface side ground texture was knitted so as to form an opening by swinging three stitches in the course direction in the course direction and moving in the course direction by three stitches alternately in the well direction at two course intervals. .

  The obtained knitted fabric was preset at 190 ° C. for 1 minute, dyed at 130 ° C., dried, and finished and set at 150 ° C. for 1 minute. Finished 36 courses / 吋: 23 wells / 吋 with a thickness of 3.0 mm A three-dimensional structure was created. Details are shown in Table 1.

(Comparative Example 6)
Using Meyer's knitting machine (RD6DPLM-77E-22G), knitting the back surface fabric using 167dtex / 48f yarn on heel L-1: L-2 according to the organization chart of FIG.筬 L-5: knitting the surface opening ground structure using 84dtex / 36f yarn on L-6, and connecting the front and back fabric structures using 33dtex monofilament yarn on the connecting yarn of −３L-3 Organized to do.

  The yarn of the surface side ground texture was knitted so as to form an opening by swinging 7 stitches in the course direction in the course direction and moving in the course direction by 7 stitches alternately in the well direction at intervals of 8 courses. .

The obtained knitted fabric was preset at 190 ° C. for 1 minute, dyed at 130 ° C., dried, and finished and set at 150 ° C. for 1 minute. Finished 36 courses / 吋: 23 wells / 吋 with a thickness of 3.0 mm A three-dimensional structure was created. Details are shown in Table 1.

In order to confirm the sound-absorbing effect of the sound-absorbing material obtained in the above production example, sound-absorbing performance measurement (measurement of sound absorption rate) was performed in accordance with JIS A 1405. The results are shown in Table 2 and FIG.

  As apparent from Table 2 above, the sound absorption rate of Example 5 is very similar to that of Example 1, and therefore overlaps Example 1 in the graph of FIG. Further, since the sound absorption rate of Comparative Example 6 is substantially the same as that of Comparative Example 5, it overlaps Comparative Example 5 in the graph of FIG.

  As apparent from Table 2 and FIG. 1, the sound absorption performance in the high frequency region of 800 Hz or higher is significantly improved in the fabric of Example 1-5 as compared with the fabric of Comparative Example 1-6. It became a thing. In particular, the fabric of Comparative Example 3 which does not have an opening on the surface side and does not have an insertion thread is excellent in sound absorption performance in a high frequency range, while having an opening on the surface side, but a non-opening dome. The sound absorption performance was also improved for Comparative Examples 1 and 2 having a shape height of less than 1.5 mm.

It is a graph which shows the sound absorptivity of this invention. It is a perspective view which shows typically a part of example of the fabric which has a sound absorptivity of this invention. It is a schematic sectional drawing of the Aa line of FIG. 2 in the fabric same as the above. It is a schematic sectional drawing of the BB line of FIG. 2 in the fabric same as the above. It is a figure which shows the motion of the incident sound in the fabric same as the above. It is a figure explaining the curvature radius of the dome shape in the fabric same as the above. It is a figure explaining the height of the dome shape in the fabric same as the above. 1 is a diagram showing a structure of Example 1. FIG. FIG. 3 is a diagram showing a structure of Example 2. FIG. 4 is a diagram showing a structure of Example 3. FIG. 6 is a diagram showing a structure of Example 4. FIG. 10 is a diagram showing a structure of Example 5. 2 is a diagram showing a structure of Comparative Example 1. FIG. It is a figure which shows the structure | tissue of the comparative example 2. It is a figure which shows the structure | tissue of the comparative example 3.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Ground structure of the incident side of sound, 2 ... Ground structure of the non-incident side of sound, 3 ... Connection thread, 4 ... Opening part, 5 ... Non-opening part (dome-shaped part), 6 ... Insertion thread | yarn.

Claims (6)

It is a three-dimensional structure formed by connecting two ground structures with a connecting thread, and has a mesh-like opening and a non-opening in the ground structure on the sound incident surface side, and the non-opening in the ground structure is It is formed in a dome shape having a curvature (1 / R) of 0.1 to 0.7 when the radius of curvature is Rmm, and the height from the bottom to the apex of the non-opening is 1.5 to 5. 0 mm, DV value calculated | required by following [1] Formula is 5-120, and the insertion thread is knitting-locked inside the ground organization by the non-incidence surface side of a sound, It is characterized by the above-mentioned. A fabric having sound absorption.
DV = (4.2 × π × A × W × c ′) / c [1]
A: Height of non-opening (mm)
W ... Length of the non-opening in the course direction (mm)
c '... Number of loops for one repeat of the non-opening in the well direction (pieces)
c ... Course density at the time of finishing the fabric having sound absorption (number of courses / 吋)   2. The non-opening (dome-shaped portion) in the ground structure on the sound incident surface side is formed of 6 to 14 loops in the course direction and 4 to 24 loops in the well direction. The fabric which has the sound absorptivity.   The fabric having sound absorbing properties according to claim 1, wherein a course or well insertion rate of the insertion yarn knitted and locked inside the ground structure on the non-incident surface side of sound is 25 to 100%.   The fabric having sound absorbing properties according to claim 1, wherein the thickness of the ground yarn forming the ground structure on the sound incident surface side is 167 to 550 dtex.   The fabric having sound absorbing properties according to claim 1, wherein the thickness of the insertion yarn knitted and locked inside the ground structure on the non-incident surface side of the sound is 167 to 1400 dtex.   The fabric having sound absorbing properties according to claim 1, wherein the fabric has a thickness of 2 to 20 mm.

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