JP2006297648A - Perforated sheet for speaker grill and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a perforated sheet for a speaker grill capable of raising an opening ratio. <P>SOLUTION: The manufacturing method of the perforated sheet for the speaker grill comprises the first process for superposing a sheet member having a large number of hole parts on a mesh member formed of a wire like member made of a resin having a core-sheath structure characterized in that the melting point of a sheath part is lower than that of a core part, the second process for performing the heat treatment of the sheet member and the mesh member after the first process at a temperature higher than the melting point of the sheath part but lower than the melting point of the core part and the third process for performing the pressing treatment of the sheet member and the mesh member after the first process. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a perforated sheet for a speaker grill that is mainly excellent in sound leakage and a method for manufacturing the same.

  In conventional acoustic equipment, a plastic plate or metal plate with a plurality of small holes is used as a speaker grill to increase the accuracy of sound loss. It may enter the audio equipment and cause malfunctions.

  In order to prevent dust, a coarse mesh or knitted fabric is attached to the back of the speaker grill. Here, when a mesh or the like is affixed to the speaker grill, an adhesive or a binder is used. However, if the amount of the adhesive or the like is large, the adhesive or the like protrudes from the small hole of the speaker grill and the small hole is formed. May be blocked. On the other hand, if the amount of adhesive or the like or the area where the adhesive or the like is applied is reduced, the adhesiveness between the speaker grill and the mesh is lowered.

Here, in order to improve the adhesion between the speaker grill and the mesh, a method has been proposed in which the mesh with the hot melt attached to the entire surface is bonded to the speaker grill by heating (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 11-251783 (paragraph numbers 0036, 0049, 0050, FIG. 1, etc.)

  However, even when hot melt is used, the melted hot melt spreads by heating at the time of adhesion and closes the small holes of the speaker grill. Here, even if the hot melt melts and spreads, in order to prevent the small holes from being blocked, it is conceivable to reduce the thread constituting the mesh or to reduce the amount of hot melt applied.

  However, in the former case, it is difficult to produce a coarse woven fabric with fine yarns, and the strength of the mesh is reduced by using fine yarns. In the latter case, it is difficult to apply the hot melt thinly and uniformly to the mesh.

  In addition, when the hot melt melts and spreads, there are parts that block the small holes, or there are parts that do not block the small holes, and there is a large variation in the diameter of the small holes when the mesh is attached. It will occur.

  In addition, since speaker grills are designed in various ways, there is a need to change the color of the mesh according to the design and color, but there is a limit to coloring hot melt, and it is unclear. It becomes a color.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a perforated sheet for a speaker grill capable of mainly improving the aperture ratio and a method for manufacturing the same.

The first invention is obtained by stacking a sheet member having a plurality of holes and a mesh member formed of a resin linear member having a core-sheath structure in which the melting point of the sheath is lower than the melting point of the core, A method for producing a porous sheet for a speaker grill, wherein the sheet member and the mesh member are pressurized while being heated at a temperature equal to or higher than the melting point of the sheath portion and lower than the melting point of the core portion. .

  In a second aspect of the present invention, a sheet member having a plurality of hole portions and a mesh member formed of a resin-made linear member having a core-sheath structure in which the melting point of the sheath portion is lower than the melting point of the core portion are overlapped. And the second step of performing heat treatment at a temperature that is equal to or higher than the melting point of the sheath portion and lower than the melting point of the core portion, with respect to the sheet member and the mesh member after the first step. And a third step of performing a pressure treatment on the sheet member and the mesh member after the first step.

  A third invention is a method for producing a perforated sheet for a speaker grill, characterized in that, in the first and second inventions, a difference in melting point between the sheath and the core is 20 ° C. or more.

  4th invention is equipped with the sheet | seat member which has a some hole part, and the mesh member formed with the resin-made linear members which have a core sheath structure whose melting | fusing point of a sheath part is lower than melting | fusing point of a core part, A perforated sheet for a speaker grill, wherein a sheath of a mesh member is fused to the sheet member.

  A fifth invention is the perforated sheet for a speaker grill according to the fourth invention, wherein the difference in melting point between the sheath and the core is 20 ° C. or more.

  In addition, the porous sheet for speaker grills manufactured by the above method can be used as a speaker grill by forming into a predetermined shape by cutting or the like, for example. The speaker grill can be incorporated in a speaker device such as a speaker or an earphone built in a portable electronic device.

  In the first and second inventions, the mesh member formed of a linear member having a core-sheath structure in which the thickness of the sheath portion is smaller than the thickness of the core portion can be overlapped with the sheet member. And the thickness of the said sheath part can be determined according to the magnitude | size of the hole of the said sheet member at least.

  Furthermore, the mesh member can be colored.

  According to the present invention, the sheet member and the mesh member are heat-treated at a temperature that is equal to or higher than the melting point of the sheath part and lower than the melting point of the core part, and by pressurizing the sheath part in the sheet member. It can be fused with the mesh member.

  Here, by forming the mesh member with a resin-made linear member having a core-sheath structure, it is possible to prevent the hole portion of the sheet member from being blocked by melting of the sheath portion. Thereby, the sound omission property when used as a speaker grille can be improved.

  In addition, by forming the linear member constituting the mesh member with resin, various colors can be given to the linear member. Thereby, the mesh member which has the color corresponding to the color of a sheet | seat member can be used, and the beauty | look at the time of using as a speaker grill can be improved.

  Examples of the present invention will be described below.

  The manufacturing method of the porous sheet for speaker grills which is Example 1 of this invention is demonstrated with reference to figures.

  FIG. 1 is a process diagram showing the steps of the manufacturing method of this embodiment.

  The sheet member 1 serving as a main body of the speaker grill is made of a synthetic resin, and examples of the synthetic resin include polyester, polyethylene, polypropylene, polystyrene, vinyl chloride, vinylidene chloride, polyvinyl alcohol, polycarbonate, polyacetal, and urethane.

  The sheet member 1 has a plurality of small holes 1a. Here, the sheet | seat member 1 is shape | molded by forming several small holes 1a using a drill, punching, etc. with respect to a flat member. About the magnitude | size (diameter) and shape of each small hole 1a, it can set suitably according to the intended purpose of using a speaker grille. For example, the small holes 1a having the same diameter can be formed on the entire surface of the sheet member 1, or the small holes 1a having different diameters can be formed.

  Here, if the small hole 1a is too large, the aesthetic appearance is impaired, and if the small hole 1a is too small, the sound omission is deteriorated. Therefore, it is preferable to set the size of the small hole 1a in consideration of these. . Specifically, the diameter of the small hole 1a is preferably set to 0.1 to 1.2 mm.

  The dustproof mesh 2 is a mesh woven with 23-135 dtex core-sheath structure yarn. The core-sheath structured yarn is composed of a core part 2a provided in the center as shown in FIG. 2 (A) and a sheath part 2b covering the core part 2a. The cross-sectional view of FIG. As shown, the thickness d2 of the sheath 2b is smaller than the thickness d1 of the core 2a.

  The number of meshes of the dustproof mesh 2 is preferably 50 to 200 meshes. Here, if the small holes 1a formed in the predetermined area of the sheet member 1 are blocked by 80% or more by the dustproof mesh 2, the sound omission is deteriorated. For this reason, it is necessary to set the number of meshes of the dustproof mesh 2 so that 80% or more of the area occupied by the small holes 1a in the predetermined area of the sheet member 1 is not blocked by the dustproof mesh 2. .

  As the material of the core-sheath structure yarn constituting the dustproof mesh 2, a synthetic resin such as polyester or nylon is used. The core-sheath structure yarn may be a monofilament or a multifilament. If a multifilament is used, the adhesion with the sheet member 1 can be improved when the sheet member 1 and the dustproof mesh 2 are bonded together as will be described later.

  Moreover, the melting point of the resin used for the core part 2a of the core-sheath structure yarn is higher than the melting point of the resin used for the sheath part 2b. This is because, as will be described later, when the sheet member 1 and the dustproof mesh 2 are heat-treated, only the sheath portion 2b is melted and bonded to the sheet member 1 with the melted resin. Specifically, if the melting point of the core 2a is set to be 20 ° C. or higher, preferably 30 ° C. or higher, higher than the melting point of the sheath 2b, only the sheath 2b can be efficiently melted.

  Since the dustproof mesh 2 is formed of the core-sheath structured yarn made of resin as described above, the dustproof mesh 2 can be easily colored. For example, the dust-proof mesh 2 can be colored according to the color of the sheet member 1 or an image can be formed. Thereby, the speaker grill comprised by the sheet | seat member 1 and the dustproof mesh 2 can be made excellent in aesthetics.

  Here, as a method for coloring the dustproof mesh 2, a known method such as a method of dyeing with a sublimation dye after weaving of the dustproof mesh 2 or an original dyeing method in which a color is first added with a pigment during spinning is used. It is done.

  The sheet member 1 and the dustproof mesh 2 having the above-described configuration are conveyed in a direction indicated by an arrow in FIG. 1 and passed through a pair of heating / pressurizing rolls 3 while being superimposed on each other. Of the core-sheath structure yarn of the dustproof mesh 2, the sheath 2 b is melted by the heat treatment by the heating / pressure roll 3. Further, the melted sheath portion 2b adheres to the sheet member 1 by the pressurizing process in the direction in which the sheet member 1 and the dustproof mesh 2 overlap, and the sheet member 1 and the dustproof mesh 2 come into pressure contact with each other.

  Then, the molten sheath 2b is solidified by cooling after passing through the heating / pressurizing roll 3, whereby the dustproof mesh 2 and the sheet member 1 are fixed.

  Here, the heating temperature in the heat treatment described above is set to a temperature at which the core portion of the sheet member 1 and the dustproof mesh 2 (core-sheath structure yarn) is not melted and only the sheath portion 2b of the dustproof mesh 2 is melted. To do. Although the heating temperature to be set varies depending on the material of the sheet member 1 and the dustproof mesh 2, specifically, it can be set within a temperature range of 60 to 200 ° C.

  The porous sheet for the speaker grill in which the sheet member 1 and the dustproof mesh 2 are integrated by the above-described processing is cut into an arbitrary size, that is, the size of the speaker device in which the speaker grill is incorporated. It becomes. The speaker grill is incorporated in a speaker device such as a box-type speaker used in an acoustic system, a speaker unit built in a portable electronic device (a mobile phone or a portable game machine), and an earphone.

  According to the present embodiment, the sheet member 1 and the dustproof mesh 2 are bonded by melting only the sheath portion 2b of the core-sheath structure yarn constituting the dustproof mesh 2. Here, when the core-sheath structured yarn is used, the thickness d2 of the sheath 2b (see FIG. 2) at the stage of spinning, that is, the amount of the sheath 2b that melts during the heat treatment described above can be set as appropriate.

  Therefore, even if the sheath portion 2b melts during the heat treatment, the thickness of the sheath portion 2b can be set so that the small hole 1a of the sheet member 1 is not blocked. That is, the thickness of the sheath 2b can be set based on the size (diameter) of the small hole 1a.

  For example, if the small hole 1a is small and the proportion of the small hole 1a in the sheet member 1 is relatively small, the possibility of closing the small hole 1a is reduced even if the sheath portion 2b is melted. The thickness of the sheath 2b can be set thick. Further, if the small hole 1a is large and the proportion of the small hole 1a in the sheet member 1 is relatively large, the sheath portion 2b is likely to melt and close the small hole 1a. Can set the thickness of the sheath 2b thin.

  On the other hand, if the amount of the sheath portion 2b to be melted is small, the adhesiveness of the sheet member 1 and the dustproof mesh 2 is lowered. Therefore, it is necessary to set the thickness d2 of the sheath portion 2b in consideration of this point. .

  By setting in this way, the opening ratio of the sheet member 1 can be improved as compared with the conventional case in the state in which the adhesion between the sheet member 1 and the dustproof mesh 2 is improved. The sound omission performance when incorporated into the speaker device can be improved.

  Here, the thickness d1 of the core 2a can be set to a predetermined value or more, and the thickness d2 of the sheath 2b can be set to a value smaller than the thickness d1 of the core 2a. If it sets in this way, it can suppress that the small hole 1a of the sheet | seat member 1 is block | closed by the fuse | melted sheath part 2b, ensuring the intensity | strength of the dustproof mesh 2 with the core part 2a.

  Moreover, by adhering the dustproof mesh 2 to the sheet member 1, it is possible to suppress dust and the like from entering the speaker device from the outside.

  Moreover, since the core-sheath structure yarn can be easily colored by forming the core-sheath structure yarn with a resin, it is possible to manufacture a speaker grill having a sense of unity and excellent in aesthetic appearance.

  Furthermore, in this embodiment, it is only necessary to weave the dustproof mesh 2 using the core-sheath structure yarn, and the process of applying the hot melt after weaving as in the prior art becomes unnecessary, and therefore the number of manufacturing steps can be reduced. Can do. Moreover, since a special apparatus for applying the hot melt is not required, the manufacturing cost can be reduced. In this respect, the manufacturing method in the present embodiment is suitable for small lot production.

  In the present embodiment described above, the sheet member 1 and the dustproof mesh 2 are overlapped by the pair of heating / pressure rolls 3 to perform the heat treatment and pressure treatment, but these steps may not be performed simultaneously. .

  That is, first, the sheet member 1 and the dustproof mesh 2 may be overlapped, and the pressure treatment and the heat treatment may be sequentially performed on the stacked sheet member 1 and the dustproof mesh 2. In other words, the overlapping process, the heating process, and the pressurizing process can be performed at different positions in the conveyance path of the sheet member 1 and the dustproof mesh 2.

  In the present embodiment, heating is performed from the sheet member 1 side and the dustproof mesh 2 side using a pair of heating / pressurizing rolls 3, but the dustproof mesh 2 only needs to adhere to the sheet member 1, You may heat only from the dust-proof mesh 2 side.

  Next, a specific manufacturing method in the present embodiment will be described.

  A plurality of small holes of φ0.5 mm were formed by punching on the entire surface of a 250 μm thick polyester sheet (Lumirror (registered trademark) manufactured by Toray Industries, Inc.). Two transfer sheets having a thickness of 150 μm printed in black with an ink jet printer were prepared.

  The polyester sheet was sandwiched between two transfer sheets so that the printing surface of each transfer sheet was in contact with the polyester sheet, and passed between heating and pressure rolls at a conveyance speed of 1.5 m / min. Here, the heating temperature in the heating / pressurizing roll was set to 195 ° C. Thereby, the black component on a transfer sheet moves to a polyester sheet, and the polyester sheet is dye | stained black.

  The black polyester sheet was wound around a roll after peeling off the transfer sheet and allowing it to cool naturally.

  On the other hand, by using polyester having a melting point of 210 ° C. as the core and using a polyester-sheath structure yarn made of polyester having a melting point of 180 ° C. as the sheath, it is made into 4f 16 dtex multifilament and woven into a 100 mesh plain weave. A dustproof mesh was created.

  The dust-proof mesh and the black polyester sheet were passed through the heating / pressurizing roll 3 while being stacked. Here, the heating temperature was set to 190 ° C., and the conveyance speed was set to 1.2 m / min. Thereby, the porous sheet for speaker grills is formed.

(Comparative Example 1)
A conventional dustproof mesh was heated and bonded to the same polyester sheet as in Example 1 described above. The method for heat bonding was the same as in Example 1, and the polyester sheet and the dustproof mesh were passed through a heating / pressure roll. The dustproof mesh in the comparative example is composed of a 70 mesh polyester multifilament with hot melt adhered to the entire surface.

  FIG. 3 is a front view showing the porous sheet for speaker grill manufactured by the manufacturing method of the present embodiment, and FIG. 4 is a front view showing the porous sheet for speaker grill manufactured by the manufacturing method of Comparative Example 1. is there.

  In Comparative Example 1, as shown in FIG. 4, it can be seen that the small holes of the polyester sheet are blocked by the molten hot melt. On the other hand, in this example, as shown in FIG. 3, it can be seen that even if the sheath portion of the core-sheath structure yarn in the dustproof mesh melts, the small holes of the polyester sheet are not blocked. That is, in this example, it can be seen that the aperture ratio of the speaker grill is higher than that of Comparative Example 1.

  On the other hand, FIG. 5 is a graph showing the aperture ratio in the speaker grilles of the present embodiment and the comparative example 1 described above. A vertical axis | shaft represents the ratio for which the small hole more than arbitrary diameters occupies among all the small holes located within the predetermined area of the porous sheet for speaker grilles. The horizontal axis represents the diameter of the small holes in the perforated sheet for speaker grill.

  The small hole here is not a small hole formed in the polyester sheet but a small hole in the polyester sheet, and indicates a portion that is not blocked by the dustproof mesh. Further, the solid line in FIG. 5 indicates the present example, and the dotted line indicates Comparative Example 1.

  As shown in FIG. 5, the graph of this example is shifted to the right side in the diagram with respect to the graph of Comparative Example 1. This indicates that the aperture ratio of the porous sheet for speaker grill of this example is higher than that of Comparative Example 1. That is, it can be seen that the sound omission is excellent.

  Specifically, in Comparative Example 1, there were almost no small holes 1a having a diameter of 250 μm or more. On the other hand, in this example, there were approximately 18% of small holes 1a having a diameter of 250 μm or more. In the present embodiment, the small holes 1a having a diameter of 200 μm or more occupy approximately 40%, whereas in the comparative example, it is approximately 0%.

  On the other hand, in the range in which the value on the vertical axis is in the vicinity of 80% to 20%, in the present example, the slope of the graph is steep in the range of φ175 to 225 μm, whereas in Comparative Example 1, φ50 The slope of the graph changes gently in the range of ~ φ250 μm compared to the present embodiment. That is, the range of the diameter of the small holes corresponding to the range where the value of the vertical axis is in the vicinity of 80% to 20% is narrower in the present example (D1) than in the comparative example 1 (D2).

  This indicates that small holes having substantially the same diameter are formed in this embodiment. In other words, this example shows that the variation in the diameters of the small holes is smaller than that in Comparative Example 1.

  Here, the larger the variation in the diameter of the small holes, the lower the sound omission property. In this example, however, the variation in the diameter of the small holes is smaller than that in Comparative Example 1 as described above. , Sound omission can be improved.

It is a figure which shows the manufacturing process of the porous sheet for speaker grilles which is Example 1 of this invention. It is the perspective view (A) and sectional drawing (B) of a core sheath structure thread | yarn. It is a front view which shows the perforated sheet for speaker grills manufactured by the manufacturing method of a present Example. It is a front view which shows the porous sheet for speaker grills manufactured by the conventional manufacturing method. It is a figure which shows the relationship between the diameter of the small hole in the porous sheet | seat for speaker grilles, and the ratio for which the small hole more than predetermined diameter accounts among all the small holes.

Explanation of symbols

1: Sheet member 2: Dustproof mesh 2a: Core 2b: Sheath 3: Heating / pressurizing roll

Claims (5)

  A sheet member having a plurality of hole portions and a mesh member formed of a resin-made linear member having a core-sheath structure in which the melting point of the sheath part is lower than the melting point of the core part are overlapped, and the sheet member and the mesh A method for producing a porous sheet for a speaker grill, wherein the member is pressurized while being heated at a temperature equal to or higher than the melting point of the sheath portion and lower than the melting point of the core portion. A first step of stacking a sheet member having a plurality of holes and a mesh member formed of a resin-made linear member having a core-sheath structure in which the melting point of the sheath is lower than the melting point of the core;
A second step of heat-treating the sheet member and the mesh member after the first step at a temperature equal to or higher than the melting point of the sheath portion and lower than the melting point of the core portion;
And a third step of performing a pressure treatment on the sheet member and the mesh member after the first step.   The method for producing a porous sheet for a speaker grill according to claim 1 or 2, wherein a difference in melting point between the sheath and the core is 20 ° C or more. A sheet member having a plurality of holes;
A mesh member formed of a resin linear member having a core-sheath structure in which the melting point of the sheath is lower than the melting point of the core,
A perforated sheet for speaker grills, wherein a sheath portion of the mesh member is fused to the sheet member. The porous sheet for speaker grills according to claim 4, wherein a difference in melting point between the sheath and the core is 20 ° C. or more.

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