JPH0390337A - Manufacture of sound absorbing porous board and apparatus therefor - Google Patents

Abstract

PURPOSE:To improve the efficiency of works by making the temperature of either one of belts be of a such level that granular materials becomes of a molten state and also making the temperature of the other belt such a level that the granular material become of a semi- molten state, then heating and compressing the granular materials filled in the cavity and after that, cooling them rapidly. CONSTITUTION:In a cavity 3 defined by a pair of endless belts 1, 2, granular materials S consisting mainly of thermoplastic resin are compressed and charged. The temperature of either one of belts is made to be of such a level that the granular materials become a molten state and the temperature of the other belt is also made to be of such a level that the granular materials become a semi-molten state and as they are heated and compressed, at the side of highly temperatured belt, the granular materials consisting mainly of the charged thermoplastic resin become a molten state and at the side of lowly temperatured belt, the granular materials become semi-molten state. And at the part defined by a highly temperatured belt, a non-air permeable layer 42 is formed and an air permeable layer 43 having openings therein is also formed, furthermore, at the inside thereof, a large number of air holes 44 are formed which communicates to these openings. Next, it is cooled rapidly while held and supported by means of paired cooling belts 8, 9, thereby obtaining a molding T.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention heats and compresses a granular material mainly composed of a thermoplastic resin that has been softened by preheating, and then cools it to form a large number of particles that are partially breathable. A method for producing a porous sound-absorbing board capable of continuously and efficiently forming a porous sound-absorbing board having openings formed therein, other parts being impermeable and having a large number of pores communicating with the openings formed therein, and the method thereof. Regarding manufacturing equipment.

(Prior art) Conventionally, regarding this type of porous sound-absorbing board with a large number of cells formed inside, JIS-A6320 (sound-absorbing perforated asbestos cement board) and JIS-A6301 (sound-absorbing perforated asbestos cement board) were used. is generally well known.

(Problems to be Solved by the Invention) One of the necessary conditions for a sound-absorbing plate is that the side on which sound is incident should be breathable, and the opposite side should be non-breathable.

All of the above-mentioned conventional products have air permeability on the entire surface, so when used as a sound absorption board, they must be joined to other non-breathable members, and the material is Since it is fragile, it is necessary to reinforce the surface (air permeable surface), and it takes a lot of man-hours to install it at appropriate locations, making it uneconomical as a whole.

In order to deal with this problem, the sound-incidence side is breathable, and the opposite side is non-breathable, and a sound-absorbing plate with a certain degree of strength is integrally molded during the molding stage. can do.

Now, if we consider the method of integrally molding a sound absorbing board that has both a breathable part and a non-breathable part,
A flat space formed by some means is filled with a granular material mainly made of thermoplastic resin, and the temperature of the upper surface forming the space is set to 12, the height at which the granular material becomes molten, and the temperature of the lower surface is set to 12. When heated and compressed to a height at which the granular material becomes semi-molten, the granular material mainly made of the filled thermoplastic resin becomes molten on the high-temperature side, and the granular material becomes semi-molten on the low-temperature side.

After that, when it is cooled, a non-porous layer is formed in the part molded on the high-temperature side, and a non-porous layer is formed in part on the part molded on the low-temperature side, but the overall A ventilation layer having a large number of openings is formed, and a large number of pores communicating with the openings are formed inside.

As a concrete means for forming the space, a mold used for general resin molding can be considered, but if we assume that a mold is used, the material in the space (in this case, the cavity) will be removed during the heating compression process. is in a softened state, and the molded product cannot be released from the mold in this state. Therefore, the entire mold must be cooled in order to cool it down.

To cool the entire mold, either separate the mold from the molding machine and place the entire mold in a water tank to cool it, or attach a separate cooling device to the mold and cool it with this cooling device. is possible.

However, when the mold is cooled by placing it in a water bath or by using a cooling device separately attached to the mold, the mold is cooled down and then filled with granular material again and then heated. However, the loss of heat energy is large, and the production efficiency is extremely poor, making it unsuitable for mass production.

In addition, if a separate cooling device is attached to the mold, the manufacturing cost of the mold will increase and the mold will become larger, which not only does not meet the needs of the recent industrial world that aims to save space and energy. The biggest problem is that it is not possible to improve work efficiency because it is an intermittent process in which a single product is obtained by going through each step of filling the granular material, heating compression, cooling, and mold release. be.

(Means for Solving the Problems) The present invention addresses the above problems, and includes heat generated by heating in advance to a softened state in the gap 3 formed by the pair of endless belts 1.2. A granular material S mainly composed of a plastic resin is filled under pressure, and the temperature of one of the pair of endless belts 1.2 is set to a height at which the granular material S becomes molten, and the temperature of the other belt is set to a level where the granular material S becomes molten. The height is such that the material S is in a semi-molten state, and the granular material S filled in the gap 3 is heated and compressed to form it, and then it is rapidly cooled.
During rapid cooling, this is cooled by a pair of cooling belts 8, which are cooled by water. A method for producing a porous sound absorbing plate, characterized in that the porous sound absorbing plate is rapidly cooled while being clamped and supported by a pair of endless belts 1. The endless belt 1 is arranged to form a gap 3.
．． A heater 5.6 is attached to the endless belt 1.2, and a pressurized supply device 7 for the granular material S is provided at one opening of the gap 3. outlet 1
In addition to these, the surfaces of a pair of cooling belts 8 and S are arranged facing each other to form a gap 10, and cooling belts 3.9 and 9. A cooling water spout part 11.12 is attached to form a rapid cooling part B, and this rapid cooling part B is connected to the rear part of the heating compression molding part A, and the endless belt 1.2 It is an object of the present invention to provide an apparatus for manufacturing a porous sound-absorbing plate characterized in that a partition plate 13 having the same height as the gap 3 is fixed on the surface of one of the belts.

(Function) According to the above means, the granular material S mainly composed of thermoplastic resin is filled under pressure into the gap 3 formed by the pair of endless belts 1.2, and the temperature of one of the belts is controlled. When the temperature of the other belt is set to a height at which the granular material is in a molten state and the temperature of the other belt is set to a height at which the granular material is in a semi-molten state, the granular material, which is mainly made of thermoplastic resin, is melted on the high temperature belt side. The granular material becomes semi-molten on the low-temperature belt side.

Through this heating compression molding process, a non-porous layer 42 is formed in the part molded on the high-temperature belt side, and a non-porous layer 42 is formed on the part molded on the low-temperature belt side. , the ventilation layer 4 has a large number of openings as a whole.
3 is formed, and a large number of pores 44 communicating with this opening are formed inside.

This is then cooled by a pair of cooling bells (cooled by water).
8. ! By clamping and supporting I, the molded product T is rapidly cooled.
can be obtained.

In addition, after the molded product T is continuously molded, it is cut by an appropriate means, or a partition plate 13 having the same height as the gap 1113 is fixed on the surface of either one of the endless belts 1.2. By doing so, a porous sound absorbing plate of a predetermined length can be obtained.

(Embodiment) A first embodiment of the present invention will be described with reference to FIG. 1 of the accompanying drawings. Reference numeral 1.2 denotes an endless belt made of stainless steel with its surfaces facing each other, support rollers 21. The endless belt 1.2 is wound around and supported by the endless belt 1.2, and the opposing parts of the endless belt 1.2 form a gap 3.

A plurality of pressure rollers 23, 24 are brought into contact with the back side of the endless belt 1.2 in order to maintain the surface pressure of the belt.

19.20 is a tension roller, and the tension roller I! , 20 are similar to the pressure rollers 23, 24,
The belt 1.2 is supported in contact with the back side of the belt 1.2 so as to maintain a predetermined tension.

Further, a drive gear 25S is attached to the support shaft of the support rollers 21 and 22.
21i are coaxially supported, and the drive gears 25 and 26
The endless belts 1.2 are moved in the same direction by engaging and rotating with each other.

4 is a side wall plate, on both sides of the gap 3 are endless belts 1.
It is fixed so that it touches 2. A heater 5.6 is fixedly supported on the back side of the endless belt 1.2.

7 is a pressurized supply device for the granular material S, and the hopper part 1
5, a feeding barrel 16, a screw 17 pivotally supported within the feeding barrel 16, and a discharge port 14 continuous to the feeding barrel 16, with the discharge port 14 connected to one opening of the gap 3. Department (
It is installed facing the intake side).

Reference numeral 18 denotes a heater for heating the granular material S while it is being fed under pressure.

These endless belts 1.2, a gap 3 formed by opposing surfaces of the endless belts 1.2, a side wall plate 4, a heater 5.6, and a pressure supply device 7 constitute a heating compression molding section A. ing.

8.3 is a cooling belt with its surfaces facing each other, and is wound and supported by support rollers 32 and 33,
The endless belt8. The opposing parts of II form a gap 10.

A plurality of pressure rollers 21, 28 are brought into contact with the endless belt 8, S from the back side in order to maintain the surface pressure of the belt.

2L30 is a tension roller, and like the pressure rollers 27 and 28, the tension roller 2L 30 contacts and supports the cooling belt 8.9 from the back side so that the belts II and 9 can maintain a predetermined tension. has been done.

Further, a drive gear 34. is attached to the support shaft of the support rollers 32.33.
35 are coaxially supported, and the cooling belts 8.
9 moves in the same direction.

11.12 is a cooling water spouting part, and the cooling water belt 8
, is fixedly supported on the back side of S.

These cooling belts 8.9, gaps 10 formed by the opposing surfaces of the cooling belts 8.9, and cooling water spouting portions 11.12.
This constitutes a rapid cooling section B.

Reference numeral 31 denotes a cutting section for a continuously molded product, and 36 a guide plate that prevents the molded product from being deformed downward when the molded product is transferred from the heating compression molding section A to the rapid cooling section B. The guide plate 36 is always urged downward by a spring 37, and its ends are in contact with the endless belt 2 and the cooling belt 9 located below.

On the 3rd, 3g is a mold release agent tank, and the mold release agent stored in the mold release agent tank 38.39 is ejected in the form of a mist from the spouting part 46.41, and is sprayed onto the surface of the endless belt 1.2. is applied to.

Next, a second embodiment of the present invention will be described with reference to FIG. 2 of the attached drawings. In this case, a partition plate 13 of the same height as the gap 3 is provided on the surface of the upper endless belt 1, and a cutting section 3 is provided at the rear of the rapid cooling section B.
1 is omitted, and in the heating compression molding section A, the molding is performed in a state where the moldings are separated into predetermined lengths.

Thus, the granular material S is placed in the hopper part 15 of the pressurized supply device 7.
When the granular material S is charged and fed under pressure by the screw 17, the granular material S is preheated by the heater 18 and is pressurized and filled into the gap 3 from the discharge port 14.

At this time, the preheating temperature of the granular material S varies depending on the type of thermoplastic resin that is the main component, but it is best to set it to a temperature of about 70 to 90% of the picat softening point of the resin used. For example, in the case of ABS resin, It is best to keep it at around 80℃.

In this way, the granular material S, which is preheated and fed under pressure, is pressurized and filled into the space F113 in a softened state, and the heater 5,
The endless belt 1.2 is heated with S, and the temperature of one of the belts, for example, the upper belt 1, is set to a height at which the granular material S melts, and the temperature of the other belt, for example, the lower belt 2 is set to a temperature such that the granular material S melts. If the temperature is set at a height at which the granular material S is in a semi-molten state, the granular material S filled under pressure will be in a molten state on the endless belt 1 side, and the granular material S will be in a semi-molten state on the endless belt 2 side. Then, heat compression molding is performed.

Thereafter, the molded product T is transferred to the rapid cooling section B along the guide plate 36, and undergoes a cooling process.
A non-ventilation layer 42 is formed in the part formed on the side of the endless belt 2, and a non-ventilation layer 42 is formed in the part formed on the side of the endless belt 2, but as a whole, a ventilation layer 43 having many openings is formed. is formed, and a large number of pores 44 communicating with this opening are formed inside.

At this time, the molded product T is sandwiched and supported between a pair of cooling belts 8.3 that are cooled by water jetted from the cooling water spouting portion 11.12, and is rapidly cooled to prevent warping or twisting of the molded product T. It can be prevented.

Further, after the molded product T is continuously molded in this manner, it is cut at the cutting portion 31 to obtain a porous sound-absorbing plate of a predetermined length.

Furthermore, in the case of the second embodiment, the molded product T having a predetermined pitch between the partition plates 13 provided on the endless belt 1 is formed during the heat compression molding stage, so there is no need to cut it after cooling. .

In addition, the granular material S used is approximately spherical and has a uniform particle size, so that the ventilation layer 42 and the non-ventilation layer 1143
The thickness of the pores 44 and the size of the pores 44 formed inside are stabilized.

Therefore, by appropriately selecting and adjusting the particle size of the granular material S, it is possible to improve the sound absorption efficiency for sounds of a specific frequency.

(Effects of the Invention) The present invention is characterized in that the gap 3 formed by the pair of endless belts 1.2 is filled with a granular material S mainly composed of a thermoplastic resin that has been heated in advance to a softened state. The temperature of either one of the endless belts 1.2 and 2 is the temperature of the granular material S.
The temperature of the other belt is set to a height at which the granular material S is in a molten state, and the granular material S filled in the gap 3 is heated and compressed to form it, and then it is rapidly cooled. Also, when rapidly cooling, the porous material is sandwiched and supported by a pair of cooling belts 8.1 cooled by water, and after being rapidly cooled, it is cut by an appropriate cutting means. A method of manufacturing a sound absorbing plate ε, a pair of endless belts 1.2 are arranged with their surfaces facing each other to form a gap 3, and side wall plates 4 are supported on both sides of the facing portions of the endless belts 1.20. , a heater 5.6 is attached to the endless belt 1.2, and a heating compression molding part A is formed by exposing the discharge port 14 of the pressurized supply device 7 for the granular material S to one opening of the gap 3; , In addition to these, a pair of cooling belts 8.9
are arranged with their surfaces facing each other to form a gap 10, and a water cooling device 11.12 is attached to the cooling belt 8.9 to form a rapid cooling IB. A porous sound absorbing plate characterized in that it is connected to the rear part of part A, and that a partition plate 13 having the same height as the gap 3 is fixed on the surface of either one of the endless belts 1.2. Since the endless belt 1.2 in the heating compression molding section A can maintain a constant heating or heat retention state, the granular material S is preheated and then filled under pressure. , molding can be performed with the minimum necessary thermal energy.

In other words, in order to manufacture the porous sound-absorbing plate obtained by the present invention with the same efficiency using a mold, a large number of molding machines and various types of molds must be installed, but the method of the present invention and According to the apparatus, molded products of various sizes can be continuously molded quickly and efficiently on one line, and production costs can be kept low.

In addition, the cooling belt 8.9 of the rapid cooling section B can sandwich and support the molded product T while cooling it as quickly as possible.
Not only is it easier to control the thickness of the ventilation layer 42 and the non-ventilation layer 43, but also a porous sound absorbing plate without warping or twisting can be obtained.

Furthermore, the porous sound-absorbing board obtained by the method of the present invention can be used in a variety of applications, such as soundproof walls on expressways and building materials, and has extremely excellent effects such as high sound-absorbing effects. .

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of the device of the first embodiment, FIG. 2 is a schematic explanatory diagram of the device of the second embodiment, and FIG. 3 is a vertical end view of a portion of a porous sound-absorbing plate obtained by the present invention. 1, 11, 3 5 7 1 g, 21. 23. 25, Code Table 2 Endless belt 3.10 Gap side wall plate 5.6 Heater pressure supply device 3.3 Cooling belt 12 Cooling water spout part partition plate 14 Discharge port hopper part 16 Feeding body screw 18 Heater 20 .2L 30 Tension roller 22.32.3
3 Support roller 24.27.28 Pressure roller 28S34.35 Drive gear 31 Cutting section 36 Guide plate 37 Spring 38.3511 Mold agent tank 4 (1,41111
Molding agent ejection part 42 Non-ventilated layer 43a Air layer 44 Air pore S Granular material T Molded product A Pressure compression molding part B Rapid cooling part

Claims (6)

[Claims] (1) Into the gap 3 formed by the pair of endless belts 1 and 2, a granular material S mainly made of thermoplastic resin that has been heated in advance to a softened state is filled under pressure, and the pair of endless belts 1,
2, the temperature of one of the belts is set to a height at which the granular material S becomes molten, the temperature of the other belt is set to a height at which the granular material S becomes semi-molten, and the granular material S filled in the gap 3 is A method for manufacturing a porous sound-absorbing board, which comprises heating and compressing it to form it, and then rapidly cooling it. (2) Into the gap 3 formed by the pair of endless belts 1 and 2, a granular material S mainly made of thermoplastic resin that has been heated in advance to a softened state is filled under pressure, and the pair of endless belts 1,
2, the temperature of one of the belts is set to a height at which the granular material S becomes molten, the temperature of the other belt is set to a height at which the granular material S becomes semi-molten, and the granular material S filled in the gap 3 is A method for manufacturing a porous sound absorbing plate, which comprises heating and compressing the plate, supporting it between a pair of cooling belts 8 and 9 cooled by water, and rapidly cooling the plate. (3) Into the gap 3 formed by the pair of endless belts 1 and 2, a granular material S mainly made of thermoplastic resin that has been heated in advance to a softened state is filled under pressure, and the pair of endless belts 1,
2, the temperature of one of the belts is set to a height at which the granular material S becomes molten, the temperature of the other belt is set to a height at which the granular material S becomes semi-molten, and the granular material S filled in the gap 3 is It is heated and compressed to form a mold, and while it is sandwiched and supported between a pair of cooling belts 8 and 9 cooled by water, it is rapidly cooled.
A method for manufacturing a porous sound absorbing plate, which comprises cutting the porous sound absorbing plate using appropriate cutting means. (4) The surfaces of the pair of endless belts 1 and 2 are arranged in a facing state to form a gap 3, and the side wall plates 4 are supported on both sides of the facing portions of the endless belts 1 and 2. , 2 are provided with heaters 5 and 6, and one opening of the gap 3 faces the discharge port 14 of the pressurized supply device 7 for the granular material S. . (5) The surfaces of the pair of endless belts 1 and 2 are arranged in a facing state to form a gap 3, and the side wall plates 4 are supported on both sides of the facing portions of the endless belts 1 and 2. . The surfaces of the belts 8 and 9 are arranged to face each other to form a gap 10, and the cooling belts 8,
Cooling water spouts 11 and 12 are attached to 9 to form a rapid cooling section B, and the rapid cooling section B is connected to the heating compression molding section A.
A manufacturing device for a porous sound absorbing board, characterized in that it is connected to the rear of a porous sound absorbing board. (6) The surfaces of the pair of endless belts 1 and 2 are arranged in a facing state to form a gap 3, side wall plates 4 are supported on both sides of the facing portions of the endless belts 1 and 2, and the endless belt 1 A partition plate 13 having the same height as the gap 3 is fixed on the surface of one of the belts in the gaps 3 and 2, and heaters 5 and 6 are attached at appropriate positions. A heating compression molded part A is formed with the discharge port 14 of the pressurized supply device 7 facing,
A gap 10 is formed by arranging the surfaces of a pair of cooling belts 8 and 9 in a facing state, and cooling water jetting parts 11 and 12 are attached to the cooling belts 8 and 9 to form a rapid cooling part B, An apparatus for manufacturing a porous sound absorbing plate, characterized in that the rapid cooling section B is provided at the rear of the heating compression molding section A.