KR100254889B1 - Speaker's diaphragm and its manufacturing method - Google Patents

Abstract

PURPOSE: A diaphragm for speaker is provided to have a partial surface coating effect by using polyester containing polypropylene in manufacturing the diaphragm. CONSTITUTION: Polyester containing polypropylene 10 to 50 wt% and pulp raw material 50 to 90wt% are mixed and dissociated. The dissociated pulp is beaten using a beater. The beaten pulp is shaped using into a diaphragm. The pulp is dehydrated, and heated in a mold heated at a temperature of 220 to 230deg.C to melt polyester containing polypropylene in the pulp. Polyester containing polypropylene is partially mixed to the inner surface of the diaphragm to have an effect of a polyester containing polypropylene polyester containing polypropylene, and only pulp exists in the outer surface. The diaphragm has the smoothness of the pulp and strength of polyester containing polypropylene.

Description

Diaphragm for speaker and manufacturing method thereof

The present invention relates to a diaphragm for a speaker and a method of manufacturing the same, and more particularly, to a diaphragm having a partial surface coating effect by polypropylene polyester and a method of manufacturing the same.

It is no exaggeration to say that the sound quality of a speaker, an acoustic transducer that converts electrical energy into acoustic energy, is determined by the diaphragm. The diaphragm is an important part of the speaker. In particular, the sound quality of the speaker depends greatly on the shape and the material of the diaphragm. In the case of diaphragm material, high elastic modulus and light weight are known to be ideal conditions for lighter speakers. In addition, the diaphragm material is preferably a large internal loss (tan δ). In addition, when the physical properties of the diaphragm are changed, it is known that the sound quality and frequency characteristics of the speaker are changed, so that a wide frequency characteristic and good sound quality can be reproduced.

In general, speaker diaphragms are manufactured using pulp. In the conventional manufacturing process of the diaphragm using pulp, first, the pulp material inflated in the process of beating is beaten by a beater, and then the beaten pulp material is cone paper in a tank. A basic mesh is used to form a basic shape, and the paper is dehydrated. Then, the dehydrated paper is inserted into the mold and heated for about 15 seconds in the temperature range of about 150-160 ℃ to obtain a diaphragm. On the other hand, a method of manufacturing a diaphragm for loudspeaker of higher quality and high quality is also known by coating a chemical on the surface of the diaphragm made of pulp material or by further bonding and synthesizing other subsidiary materials. There is also a method of producing a diaphragm using a single body such as a carbon sheet. However, up to now, the diaphragms obtained from the method are not suitable for mass production due to the lack of sound quality of the speaker and the complicated manufacturing process.

Accordingly, an object of the present invention is to provide a vibration plate for a speaker having high quality sound reproduction and a wide frequency band, because the softness of the pulp vibration plate and the strong sound of the synthetic fiber can be generated at the same time.

Another object of the present invention is to provide a method for gymnastics to the above-mentioned diaphragm through a simple process.

1 is a comparison of sound quality characteristics according to frequency for the diaphragm of the prior art and the present invention.

Figure 2 is a tissue photograph of the inner surface of the diaphragm of the prior art and the present invention.

The present invention for achieving the above object is composed of polyester containing polypropylene: 10-50% by weight and pulp material: 90-50% by weight, the polyester-containing polypropylene is partially mixed on the inner surface And it relates to a diaphragm for a speaker consisting of only the pulp on the outer surface. In addition, the present invention comprises the steps of mixing the pulp material: 50-90% by weight and polyester-containing polypropylene: 50-10% by weight; Beating the understood pulp with a fryer; Poring the beaten pulp into a diaphragm shaped mesh plate; And dewatering the corrugated paper, followed by molding the dehydrated paper into a mold heated to melt the polyester-containing polypropylene in the paper.

Hereinafter, the present invention will be described in detail.

The diaphragm for the speaker of the present invention contains a polyester-containing polypropylene (hereinafter, only PP) and pulp, so that the PP is partially mixed on the inner surface of the diaphragm, so that the PP is partially coated on the pulp surface.

The PP and pulp is preferably contained in about 10-50% by weight and 90-50% by weight, respectively. If the PP content is less than 10% by weight or the pulp is more than 90% by weight, the partial coating effect due to the blending of the PP is insufficient, on the contrary, the PP content is more than 50% by weight or the pulp is 50% by weight. If it is less than the sound speed transmission of the speaker is good, but the softness of the diaphragm lacks the original sound reproduction.

PP used in the present invention is a synthetic resin in which a polyester bark (polyester) is mixed with a polypropyl pen resin, more preferably in the form of short fibers. Such PP may have a specific gravity lower than that of pulp, and thus may easily float to the inner surface of the diaphragm during the portrait process.

Hereinafter, the manufacturing method for the diaphragm of the present invention will be described in detail.

In order to manufacture the diaphragm of the present invention, it is understood that 50-90% by weight of pulp material is first dissolved in water. At this time, about 10-50% by weight of the PP kneaded in the pulp material in the process of understanding. The understood pulp is beated and cut to a certain size in the same way as in the normal blasting process.

The pulp, which is beaten to a certain size, is portrait from a mesh plate installed in the tank into a diaphragm-shaped sheet of paper. Since PP has a lighter specific gravity than pulp, it rises in portrait paper. Therefore, the PP remains partially on the inner surface of the diaphragm, and only pulp remains on the outer surface of the diaphragm.

Then, the water in the tank is drained to sufficiently dewater the treated grassland. The dehydrated paper is then molded in a mold heated to the extent that the polyester-containing polypropylene in the paper melts. Molding is suitable for a temperature range of about 220-230 ° C. When the molding is performed at less than 220 ° C, the PP is not completely melted, and thus the coating effect by PP is insufficient. In the molded diaphragm, the PP melts and the effect is as if the PP coating was applied to the inner surface of the diaphragm. As a result, the diaphragm of the present invention combines the softness of the pulp with the toughness of the PP itself, resulting in a completely different sound quality than the conventional diaphragm.

Hereinafter, the present invention will be described in detail with reference to Examples.

Example 1

As shown in Table 1, pulp material and polyester-containing polypropylene short fibers were kneaded, and the mixed pulp material was mixed with 100 times of water to sufficiently understand pulp fibers. The pulp understood was beaten to a certain size with a pulverizer, and the beaten pulp was portrayed as a diaphragm-shaped mesh plate. Then, the dehydrated paper was dehydrated, and the dehydrated paper was pressed in a mold heated to 225 ° C. for 15 seconds to form a 0.4 mm thick diaphragm.

In addition, a diaphragm (traditional material) using only conventional 100% pulp was prepared for comparison with the present invention.

For each diaphragm thus manufactured, the speed of sound, modulus of elasticity, and internal loss were measured, and the results are shown in Table 1 below.

Moreover, the sound pressure according to frequency was measured about the conventional material and the invention material (2), and the result is shown in FIG.

As shown in Table 1, the invention (1-3) was found to exhibit excellent characteristics as a diaphragm for a speaker because the sound velocity is faster than the conventional 100% pulp, the elastic modulus and internal loss is large.

In addition, as shown in FIG. 1, in the case of the present invention (2), it was found that the sound quality is more stable in the wide frequency band than in the case of the conventional material.

The reason why this invention material is superior to the conventional pulp vibration plate is confirmed also in the result of FIG. 2 which shows the inner surface structure of the vibration plate of the conventional material and the invention material (2). Figure 2 (a) is a structure that observed the inner surface of the conventional pulp vibration plate 50 times, 250 times, respectively, and Figure 2 (b) shows the inner surface of the vibration plate of the invention material (2) 50 times, 250 times respectively Organization. That is, as shown in FIG. 2, in the case of the conventional material, only pulp fibers are entangled with each other, whereas in the case of the invention material 2, PP is bonded to the pulp fiber and partially coated.

On the other hand, in the case of the present invention, the sound velocity and elastic modulus increase as the PP content generally increases, but the internal loss affecting the sound quality increases and decreases as the PP content increases. This is thought to be because the PP increases in the inside of the diaphragm as the content of the PP increases, thereby the hardening of the diaphragm itself, and the internal loss is reduced when a certain amount is added.

Example 2

A diaphragm was manufactured in the same manner as in Example except that pulp and PP mixed with the same composition as the inventive material 2 were molded under the conditions shown in Table 2 below.

As shown in Table 2, in the manufacturing process according to the present invention was found that it is preferable to be carried out at a temperature such that PP is completely melted above all. And, the molding temperature was found to be the optimum temperature range of about 220-230 ℃.

As described above, the diaphragm of the present invention is melted PP and the inner surface of the diaphragm is like PP coating, so that the softness of the pulp vibrating plate and the strength of the synthetic fiber are combined, resulting in higher sound quality and wider range of original sound than the conventional diaphragm. It is effective to have a frequency band of. In addition, the manufacturing process is also much simpler than the conventional coating method has an effect suitable for mass production.

Claims (5)

Polyester-containing polypropylene: 10-50% by weight and pulp material: 90-50% by weight, the inner surface of the polyester polypropylene is partially mixed and the outer surface of the speaker consisting of only pulp tympanum. Mixing and understanding pulp material: 50-90% by weight and polyester-containing polypropylene: 50-10% by weight; Beating the understood pulp with a fryer; Poring the beaten pulp into a diaphragm shaped mesh plate; And dewatering the corrugated paper, followed by molding the dehydrated paper into a mold heated so that the polyester-containing polypropylene in the paper melts. The method of claim 2, wherein the polyester-containing polypropylene is in the form of short fibers. 3. A method according to claim 2, wherein the portrait is drained of water such that the polyester-containing polypropylene floats on the inner surface of the paper. The method of claim 2, wherein the molding is performed in a temperature range of 220-230 ° C.

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