KR20230095684A - Grill fabric for vehicle speaker and method for preparing thereof - Google Patents

Abstract

The present invention relates to a method of manufacturing a grille fabric for a vehicle speaker and a grille fabric for a vehicle speaker manufactured therefrom, wherein the method comprises: a step (a) of manufacturing a composite yarn using at least one type of fiber selected from natural fibers and synthetic fibers as a weft and a warp, respectively; a step (b) of coating the composite yarn manufactured in the step (a) by impregnating the same with an aqueous urethane solution having a concentration of 5 to 30 wt%; and a step (c) of manufacturing a fabric from the urethane-coated composite yarn in the step (b). In the present invention, by manufacturing a speaker grille, which previously used a punched net of a metal thin plate, in a form of a fabric using various yarns, a load transmitted to the speaker grille is minimized to prevent the speaker grille from breaking, the speaker grille can be manufactured lighter with improved productivity, and the speaker grille can be safely protected from various adverse conditions applied from the outside of the vehicle without affecting acoustic effects of the vehicle speaker.

Description

Grill fabric for vehicle speakers and method for manufacturing the same {Grill fabric for vehicle speaker and method for preparing thereof}

The present invention relates to a grill fabric for a speaker of a vehicle and a manufacturing method thereof, and more particularly, to a light and eco-friendly grill fabric for a speaker grill of a vehicle and a method of manufacturing the same by converting an existing steel or aluminum grill net into a fabric form. .

A vehicle speaker is installed that converts an electrical signal generated in a vehicle's audio/video system into vibration of a diaphragm and generates dense waves in the air while radiating sound waves. A conventional vehicle speaker structure includes a speaker including a speaker body, a cone-shaped speaker housing, and a speaker cone. The speaker grill is mounted through thermal fusion bonding or screw bonding.

Steel-type speaker grills can cause direct injury to occupants, and in some cases, even side airbags can be damaged, so that the occupants cannot be protected in the event of a side collision of the vehicle, and the degree of personal injury to occupants can increase.

The speaker grill, which is placed in front of the speaker housing, is leading a more convenient and affluent life in modern society through the development of the electronics industry. The electronics industry is developing rapidly as it becomes more precise and more miniaturized. Due to the advanced specifications of future electric vehicles, ultra-precision and subminiature parts are being used and designed and developed so that external stimuli do not affect the parts. External stimuli include shock, electromagnetic waves, moisture, and dust, and living dust is neglected in the environment where electronic products are used. It is designed and developed with sufficient sealing in mind to prevent foreign substances from penetrating into the device. However, due to the performance of the product, the part that cannot be completely sealed is the speaker part. Therefore, a speaker of a car used outdoors is protected by a speaker grill.

The role of the speaker grill is, firstly, to protect the speaker unit, secondly to convert the sound, and thirdly to improve the aesthetics of the speaker's appearance. In general, the diaphragm of a speaker unit is made of a very sensitive material, so it is easily damaged if there is no separate protection device. The speaker grill is installed to cover the speaker unit in order to prevent external damage such as scratches, punctures, and inflow of dust of vibration waves of the speaker unit.

The speaker unit reproduces sound by generating vibrations in the air. When the speaker grill is removed and the sound is heard, some listeners may feel rough. This feeling is due to the sound of all bands being transmitted to the listener at a certain time difference due to the reverberation of the sound generated by the speaker unit. The speaker grill is installed at a certain distance from the speaker unit to form a space of a certain volume between the speaker unit and the speaker grill, so that the sound generated by the speaker unit collides with the speaker grill and is reflected and mixed with the newly created sound, resulting in reverberation. It plays a very important role in minimizing the noise and making it feel soft.

In general, the diaphragm of a microspeaker is mainly made of a very thin polymer having a thickness of several tens of microns (10 to 15 μm). Therefore, in order to safely protect the thin diaphragm from any physical contact or impact, a grill made of a thin metal plate is installed at the front of the diaphragm. At this time, several holes are drilled in the metal grill so that the sound generated from the diaphragm can smoothly pass through the grill. However, the shape and size of these holes show a lot of difference depending on the manufacturer or model. This difference may be the cause of greatly changing the acoustic characteristics of the microspeaker. This is because the acoustic impedance in the diaphragm can be changed by the hole in the grill. These characteristic changes have been handled only by the qualitative experience of microspeaker engineers. There are many practical factors that can affect the sonic characteristics of a microspeaker. Among them, the acoustic characteristics of the microspeaker may also be changed by the size and shape of the holes made in the grill.

Therefore, there is a demand for manufacturing an environmentally friendly speaker grill for a vehicle that can solve the problems of conventional speaker grills using steel or metal without affecting the acoustic characteristics of the vehicle speaker.

Accordingly, an object of the present invention is to provide a speaker grill fabric for a vehicle using various fabrics in place of steel or metal materials to solve the conventional problems in the speaker grill of a vehicle.

In addition, an object of the present invention is to provide a method for manufacturing a speaker grill fabric for a vehicle having the above characteristics.

In order to achieve the above object, a method for manufacturing a grill fabric for a speaker of a vehicle includes steps (a) of manufacturing composite yarns by using at least one selected from natural fibers and synthetic fibers as weft yarns and warp yarns, respectively, in step (a) It may include a step (b) of impregnating and coating the composite yarn by impregnating it with an aqueous urethane solution having a concentration of 5 to 30% by weight, and a step (c) of manufacturing a fabric from the urethane-coated composite yarn in the step (b).

According to one embodiment of the present invention, the natural fiber may be at least one selected from organic cotton, corn fiber, bamboo fiber, and linen.

According to one embodiment of the present invention, the synthetic fibers may be at least one selected from recycled polyester, recycled nylon, nylon, and aramid fibers.

The composite yarn of step (a) is preferably prepared by twisting each weft yarn and warp yarn 180 to 400 times per meter.

According to one embodiment of the present invention, when the yarns used as the warp and weft yarns are spun yarns, the Nec ranges from 20' to 40' (130 denier to 265 denier when filaments are used), and the yarns used as the warp and weft yarns are blended. Red or ply-twisted yarn is preferably Nec 16' (ATY 330 denier to 840 denier).

Step (b) of impregnating the composite yarn prepared in step (a) with an aqueous urethane solution is preferably performed by a two-step process of primary coating through a spray method and secondary coating by an impregnation method.

The fabric produced through step (c) may have any one form selected from plain weave, twill weave, and changed plain weave.

In addition, the present invention can provide a grill fabric for a speaker of a vehicle manufactured according to the above manufacturing method.

The speaker may be any one selected from among a center speaker in a crash pad, left and right woofer speakers in a front door, and subwoofer speakers in a rear seat trunk hood.

In addition, the grill fabric disposed in the vehicle speaker has a feature that does not degrade the acoustic effect of the vehicle speaker.

In the present invention, the load transmitted to the speaker grill is minimized by manufacturing the speaker grill in the form of fabric using various yarns, which used punching nets of thin metal plates in the past, thereby preventing breakage of the speaker grill and making the speaker grill lighter. and can improve productivity.

In addition, it has an effect of safely protecting the speaker even in various adverse conditions applied from the outside of the vehicle without affecting the sound effect of the vehicle speaker.

In addition, the technology accumulated while developing the grill fabric according to the present invention can be applied not only to automotive speaker grills but also to TV and Audio speakers, and can be actively utilized in future consumers' pursuit of high quality and energy saving.

1 is an exemplary view of a material yarn for a speaker grill for a vehicle,
2 is a structure of a fabric for a speaker grill for a vehicle according to an embodiment of the present invention;
Figure 3 is a perspective view showing the fabric of the speaker shown in Figure 2;

Hereinafter, the present invention will be described in more detail.

Terms used in this specification are used to describe specific embodiments and are not intended to limit the present invention.

As used herein, the singular form may include the plural form unless the context clearly indicates otherwise. Also, when used herein, "comprise" and/or "comprising" specifies the presence of the recited shapes, numbers, steps, operations, elements, elements, and/or groups thereof. and does not exclude the presence or addition of one or more other shapes, numbers, operations, elements, elements and/or groups.

The present invention relates to a grill fabric for a vehicle speaker and a manufacturing method thereof.

A grill made of a thin metal plate is used on the front of the microspeaker to protect the diaphragm. The grill is perforated so that sound generated from the microspeaker unit can pass through. It was found that the smaller the size of the holes, the larger the acoustic impedance by the holes, and thus the larger the effect on the overall acoustic impedance of the microspeaker. This means that the smaller the size of the hole, the greater the acoustic characteristics generated from the microspeaker unit can be changed due to the grill.

Through this theoretical acoustic analysis, the acoustic characteristics of the grill can vary depending on the weaving method of the fiber grill, the thickness of the yarn used, and the change in fiber processing technology.

The speaker grill fabric in the present invention is formed to have a thickness in the range of about 0.1 mm to 0.5 mm, preferably about 0.2 to 0.3 mm. This thickness is characterized by the required structural rigidity and thin enough that sound can pass through it without significant degradation.

Accordingly, the speaker grill fabric of the present invention does not need to be bonded to the speaker grill with a separate adhesive since the preformed speaker grill fabric has sufficient stiffness to hold its shape.

Also, it can be easily separated from the speaker grill so that it can be drawn separately. Removal and reinstallation of the present preformed grill fabric is relatively straightforward due to its rigidity. Moreover, a variety of fabric materials other than polyester are also suitable for use as the preformed grill cloth of the present invention.

In the grill fabric for a vehicle speaker according to the present invention, at least one selected from natural fibers and synthetic fibers is used as a weft and a warp, respectively, to produce a composite yarn (a), the composite yarn prepared in step (a) It can be prepared through the step (b) of impregnating and coating in an aqueous urethane solution having a concentration of 5 to 30% by weight, and the step (c) of manufacturing a fabric from the urethane-coated composite yarn in the step (b). explain in detail.

(a) composite yarn manufacturing step

First, in the first step, it is a step of making composite yarn, which can be achieved by using one or more types selected from natural and synthetic fibers as weft and warp, respectively, using a universal plying machine.

Natural fibers that can be used as the weft and warp may include organic cotton, corn fiber, bamboo fiber, linen, and the like, and organic cotton does not refer to all cotton fibers manufactured by organic methods as organic cotton, but necessarily means that they have received certification standards. do. Organic cotton certification standards here include GOTS (Global Organic Textile Standards), Oeko-Tex Processing Standards, and Fair Trade. In particular, GOTS is a globally integrated certification standard that certifies environmentally friendly and sustainable production methods. .

In addition, since the weight of the fabric for producing a thickness in the range of 0.1 mm to 0.5 mm of the grill fabric according to the present invention reaches 250 to 320 g / m 2, the range of constituent yarns required for the fabric suitable for this is the warp and weft yarns. If the yarn used is a spun yarn, it is preferable to form a structure with Nec 20 '~ 40' (130 denier to 265 denier in the case of filament).

In addition, when these yarns are used in a blended or ply-twisted yarn, it is preferable to process yarns up to Nec 16' (ATY 330 denier ~ 840 denier) in thickness of the final yarn used, but if the thickness exceeds the above, resonance phenomenon Noise amplification may occur due to the constructive interference of sound waves, and in the sound absorption test, the bulky material of the fabric absorbed noise particularly well in a specific frequency range and the sound absorption effect increased.

In addition, the synthetic fiber that can be used as the weft and warp is preferably one or more selected from recycled polyester, recycled nylon, nylon, and aramid fibers (including para-aramid and meta-aramid). In the present invention, it is most preferable to use recycled synthetic fibers for manufacturing environmentally friendly grill fabrics, and a small amount of general synthetic fibers may be used.

In the present invention, spun yarns may be plied by combining natural fibers and natural fibers, or natural fibers and synthetic fibers, or composite twisted yarns may be used for each weft and warp yarn. In the present invention, the load transmitted to the speaker grill is minimized through the combination of these material yarns, so that breakage of the speaker grill can be prevented.

The composite yarn of the present invention is preferably prepared by twisting 180 to 400 times per 1 meter of each weft yarn and warp yarn. If the number of twists is less than 180 times per meter, it is difficult to maintain the shape of the fabric, and if the number of twists exceeds 400 times per meter, there is a problem in that it is difficult to maintain a constant density during weaving due to excessive twisting.

(b) aqueous urethane coating step

In the second step (b), the composite yarn prepared in step (a) is impregnated with an aqueous urethane solution having a concentration of 5 to 30% by weight, coated, and dried.

In the present invention, it is intended to impart abrasion resistance and surface hardness to the composite yarn prepared by impregnating and coating the composite yarn in an aqueous urethane solution. The concentration of the aqueous urethane solution used is preferably 5 to 30% by weight because it has excellent permeability and adhesion to the fiber yarn.

In the case of impregnating the composite yarn in the aqueous urethane solution, the impregnation time and process method can be changed differently depending on the fineness of the fiber yarn, that is, the diameter, and it is preferable to complete it by a two-step process using a spray method and an impregnation method. .

In the embodiment of the present invention, DW-9240N of Daewon Chemical was used as the aqueous urethane solution, which is poly (tetramethylene glycol), (Poly (tetramethylene glycol), PTMG), 4,4'-methylene bis (cyclohexyl Isocyanate) (4,4'-methylene bis(cyclohexyl isocyanate), H12MDI), 2,2-dimethylol propionic acid (DMPA) and caprolactone acrylate (CLA) are used As a waterborne polyurethane acrylic copolymer (WPUA) synthesized by the above process, it has excellent tensile strength and water resistance.

Since general polyurethane, like most polymers, is not dispersible in water, it is possible to emulsify or disperse isocyanate (NCO) group-terminated hydrophobic polyurethane prepolymers by applying a suitable emulsifier and strong shear, but the dispersed phase obtained in this way Silver has a large particle size and poor storage stability.

Therefore, it is essential to have some kind of hydrophilic group in the structure before dispersing in an aqueous medium, and most WPUs are prepared in the form of ionomers with ionic groups in the structure. However, since the ionic group used at this time has intrinsic hydrophilicity, the average particle size decreases as the content of the ionic group increases, but mixing of the ionic group does not facilitate chain extension and helps the stability of the final particle after chain extension. can't give In addition, as a hydrophilic group is introduced into the polyurethane structure, it has a slow drying rate and is sensitive to hydrolysis, resulting in insufficient water resistance and poor chemical resistance.

Therefore, as in the present invention, when caprolactone acrylate (CLA) having an OH group is bonded to the NCO group present at both ends of the polyurethane chain, physical properties that are insufficient only with aqueous polyurethane can be supplemented. CLA has a carbonyl group and a hydroxyl group in its own structure, so it is known to have good reactivity and excellent physical properties such as flexural strength, impact strength and adhesive strength. In addition, the resin containing CLA as a branched chain improves adhesion during coating, resulting in improved corrosion resistance, and the improvement of flexural strength increases flexibility and improves processability, so it is suitable for application as a coating resin.

Further, in the present invention, the curing agent of the water-dispersed polyurethane resin may be added in an amount of 5 to 20% based on the weight of the water-dispersed polyurethane resin, and the curing agent is not particularly limited. In the examples of the present invention, EASAQUA WAT-3 was used.

(c) fabric manufacturing step

The last step is a process of manufacturing a fabric from the urethane-coated composite yarn in step (b). At this time, the fabric may be one of various fabrics such as plain weave (PLAIN), twill weave (TWILL), and changed plain weave (BASKET) as shown in FIG. 1, but any one of them is not specified.

As shown in the photograph of FIG. 2, the grill fabric manufactured through the above process is disposed in any one speaker selected from the center speaker of the crash pad part of the vehicle, the left and right woofer speakers of the front door, and the subwoofer speaker part of the rear seat trunk hood. it could be In addition, the grill fabric according to the present invention can be applied not only to automotive speaker grills but also to various speakers used for TV and audio.

In addition, a picture of placing the grill fabric manufactured according to the present invention on an actual vehicle speaker is shown in FIG. 3 below.

Hereinafter, preferred embodiments of the present invention will be described in detail. The following examples are only for illustrating the present invention, and the scope of the present invention should not be construed as being limited by these examples. In addition, in the following examples, specific compounds were exemplified, but it is obvious to those skilled in the art that equivalent or similar effects can be exerted even when equivalents thereof are used.

Examples 1-5

Composite yarns were prepared using a conventional plying machine using warp yarns and weft yarns having the configurations shown in Table 1 below. In the manufacture of composite yarn, in each example, 180 times (Example 1), 230 times (Example 2), 300 times (Example 3), 360 times (Example 4), 400 times (Example 5) per 1 meter of each yarn ) was twisted to maintain a constant density and shape.

Prepare an aqueous solution at a weight ratio of 10:1 for each of the composite yarns prepared above, such as water-dispersible polyurethane resin DW-9240N and EASAQUA WAT-3 (curing agent), dilute it with water 50:50, and adjust the chamber temperature to obtain an initial In chamber 1, the primary coating was performed at 270° C. by spraying, and in chamber 2, coating was performed at 220° C. by impregnation. After that, it was prepared by drying with natural cold air. Then, a fabric was manufactured using a rapier loom with each of the urethane-coated composite yarns.

warp yarn weft yarn Example 1 Organic Cotton (Nec 20'
+ Recycled Nylon (130 Denier) Organic Cotton (Nec 20'
+ Recycled Nylon (130 Denier) Example 2 Linen (Nec 11'
+ Recycled polyester (150 Denier) Linen (Nec 11'
+ Recycled polyester (150 Denier) Example 3 Nylon high tenacity yarn (330 Denier) Nylon high tenacity yarn (420 Denier) Example 4 Recycled Polyester (300 Denie) Recycled Polyester (450 Denier) Example 5 Recycled polyester (300 Denier)
+ Nylon high tenacity yarn (330 Denier) Recycled polyester (300 Denier)
+ Nylon high tenacity yarn (330 Denier)

Experimental Example 1: Confirmation of Acoustic Loss

The speaker sound evaluation for each fabric manufactured according to Examples 1, 3, and 5 was measured for each frequency to determine whether or not sound loss was caused by the fabric, and the results are shown in the following 4 to 6, respectively.

In order to compare with the fabric manufactured according to the present invention, a speaker grill using a metal wire currently on the market as a speaker grill for vehicles was used as an unapplied product and compared with a product to which the fabric according to the present invention is applied.

Referring to FIGS. 4 to 6 , it was confirmed that the sound loss effect for all fabrics (applied) of Examples 1, 3, and 5 was superior to that of a speaker grill using a metal wire (not applied).

From these results, even if the vehicle speaker grill is manufactured in the form of a fabric as in the present invention, the load transmitted to the speaker grill is minimized due to the nature of the fabric without affecting the acoustic effect of the vehicle speaker, thereby preventing breakage of the speaker grill, It was confirmed that the speaker grill can be made lighter and productivity can be improved.

Claims (10)

Preparing a composite yarn by using at least one selected from natural fibers and synthetic fibers as weft and warp yarns (a);
(b) coating the composite yarn prepared in step (a) by impregnating it with an aqueous urethane solution having a concentration of 5 to 30% by weight; and
A method of manufacturing a grill fabric for a vehicle speaker comprising the step (c) of manufacturing a fabric from the urethane-coated composite yarn in step (b).
According to claim 1,
The method of claim 1, wherein the natural fiber is at least one selected from organic cotton, corn fiber, bamboo fiber, and linen.
According to claim 1,
The synthetic fiber is a manufacturing method of at least one selected from recycled polyester, recycled nylon, nylon, and aramid fibers.
According to claim 1,
The method of manufacturing the composite yarn of step (a) is prepared by twisting each weft and warp yarn 180 to 400 times per meter.
According to claim 1,
If the yarn used as the warp and weft is spun yarn, the Nec ranges from 20' to 40' (130 denier to 265 denier for filament),
If the yarn used as the warp and weft is a blended or plied yarn, Nec 16 '(ATY 330 denier to 840 denier).
According to claim 1,
Step (b) of impregnating the composite yarn prepared in step (a) with an aqueous urethane solution is performed by a two-step process of primary coating through a spray method and secondary coating by an impregnation method.
According to claim 1,
The fabric produced through step (c) has a form selected from plain weave, twill weave, and changed plain weave.
A grill fabric for a vehicle speaker manufactured according to the manufacturing method of claim 1.
According to claim 8,
The speaker grill fabric for a vehicle speaker, wherein the speaker is any one selected from the center speaker of the crash pad part, the left and right woofer speakers of the front door, and the subwoofer speaker of the rear seat trunk hood.
According to claim 8,
The grill fabric for a vehicle speaker, wherein the grill fabric for a vehicle speaker does not degrade the acoustic effect of the vehicle speaker.

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