JP3618595B2 - Production method of soundproofing material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a soundproof material, and more specifically, a raw material mainly composed of a light-weight chip-like solid and a thermoplastic fibrous binder are mixed, and the mixed treatment material is heated and pressed to form a fibrous material. The present invention relates to a method for manufacturing a soundproof material, in which chip-shaped solids are bound to each other by heat melting of a binder and a soundproof material is formed.
[0002]
The present invention is a soundproofing material that recycles, for example, non-metallic shredder dust, which is a waste material of a vehicle, as a raw material in terms of raw materials, and a soundproofing material that is used for vehicle applications such as a dash silencer and a floor silencer It is particularly preferably applied to materials.
[0003]
[Prior art]
One of the leading technologies for producing soundproof materials such as automotive dash silencers and floor silencers with low bulk density and excellent soundproofing and vibration isolation performance, raw materials made of lightweight solid chips and thermoplastics There is a method of mixing and heating with a fibrous binder.
[0004]
In particular, when the non-metallic shredder dust extracted from, for example, vehicle waste is effectively used as the light-weight chip-like solid material, this is economical and significant from the viewpoint of material recycling.
[0005]
In “granular composite material and manufacturing method thereof” disclosed in Japanese Patent Application Laid-Open No. 8-112584, a fibrous thermoplastic as a connecting material is used for a chip-like solid material such as urethane, plastic, and rubber derived from shredder dust. A method of manufacturing a composite material secondary processed body that is mixed with a resin and heated and solidified to form a solid body having a predetermined shape is disclosed.
[0006]
Furthermore, in the specification attached to the application of Japanese Patent Application No. 10-589 relating to the applicant's application, the application of the chip-like solid material and the thermoplastic fibrous binder is compressed. Proposes a method for producing a soundproofing material in which the two are satisfactorily mixed and the both are mixed well by defibrating and mixing to scrape them little by little, and the chip-like solids are bound to each other by thermal melting of the fibrous binder. .
[0007]
[Problems to be solved by the invention]
By the way, in order to satisfactorily bind the raw material made of chip-like solids with a thermoplastic fibrous binder and maintain a uniform material in each part of the soundproofing material, the chip-like solids and the fibrous binder are It is required to be finely and uniformly dispersed and mixed with each other.
[0008]
The technique disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 8-112584 is that the main point of the invention is to control the size and bulk density of various chip-like solids to give shredder dust processing uniformity. Therefore, regarding the requirement that “the chip-like solid and the fibrous binder are finely and uniformly dispersed and mixed with each other”, a technique that is notable in particular is not disclosed.
[0009]
On the other hand, in the method for producing a soundproof material described in the specification attached to the application of the above Japanese Patent Application No. 10-589, the fine defibration of the fibrous binder and the mixing with the chip-like solids are simultaneously performed in a small amount. Therefore, an excellent effect is obtained in that both are finely and uniformly dispersed and mixed with each other.
[0010]
However, after the filing of the above Japanese Patent Application No. 10-589, the present inventor has further researched, and as a result, the fibrous binder is constrained to a compressed state from the point that the specific gravity is significantly smaller than the chip-like solid. It has been found that there is room for further improvement in the supply form of the aggregate of the chip-like solid material and the fibrous binder used for the scraping treatment.
[0011]
Therefore, the present invention provides a method for producing a soundproof material in which chip-like solids are bonded to each other via a thermoplastic fibrous binder, and the chip-like solid and fibrous binder are more ideally finely and uniformly dispersed.・ Provide technology that can be mixed.
[0012]
[Means for Solving the Problems]
The configuration of the present invention for solving the above-mentioned problems is a mixing process in which a raw material mainly composed of a light-weight chip-like solid and a thermoplastic fibrous binder are mixed, and a processing material is heated and pressed. And the step of bonding the chip-like solids to each other by heat melting of the fibrous binder and the press-molding of the soundproofing material, and the mixing step includes the chip-like solids as upper and lower layers. It is a method for producing a soundproofing material, including a defibrating and mixing process in which a laminated body having a fibrous binder as an intermediate layer is restrained in a compressed state and is scraped little by little by a scraping projection member.
[0013]
[Operation and effect of the invention]
In the defibrating and mixing process in the mixing step, a laminated body of chip-like solid matter and fibrous binder constrained in a compressed state is prepared, and the laminated body is scraped little by little using a scraping projection member. Each time scraping, a small amount of fibrous binder is forcibly chopped and scraped in a finely defibrated state, and at the same time, a small amount of chip-like solids are also scraped. The fiber binder that has been defibrated to the object is in a state of being settled.
[0014]
Therefore, in the aggregate of scraped materials (hereinafter referred to as “defibration mixed treatment material”), in a state where the fibrous binder defibrated into individual chip-like solids is attached, Both are finely and uniformly dispersed and mixed.
[0015]
In addition, the chip-like solid material and the fibrous binder to be scraped are supplied as a laminated body in which the fibrous binder having a remarkably small specific gravity is used as an intermediate layer, and the upper and lower layers thereof are chip-like solid materials. The solid solid and the fibrous binder are dispersed and mixed extremely uniformly without causing a distribution density gradient due to a difference in specific gravity.
[0016]
FIG. 1 shows an image of this action. FIG. 1 (a) shows a laminate of chip-like solid 1 and fibrous binder 2 before defibrating and mixing treatment, and fibrous binder 2 is defibrated to form a sheet-like intermediate layer 2a. Upper and lower layers 1a made of chip-like solids 1 are formed on both upper and lower sides. The intermediate layer 2a and the upper and lower layers 1a are actually scraped while being constrained in a densely compressed state.
[0017]
FIG. 1 (b) shows the state of the defibration mixed material, and the fibrous binder 2 of the intermediate layer 2a is forcibly finely defibrated by the scraping process, and the chip-like shape that constitutes the upper and lower layers 1a. The solids 1 are individually settled and both are finely and uniformly dispersed and mixed.
[0018]
Producing soundproofing materials that have the soundproofing performance, strength, shape retention, etc. as designed and that do not have non-designed quality variations for each part by using the above-mentioned defibrated material for the binding process can do.
[0019]
In addition, suppose that the chip-like solid substance and the fibrous binder subjected to the scraping treatment were aggregates of a two-layer structure in which the chip-like solid substance was dispersed on the undefibrated sheet of the fibrous binder. Even in this case, both the chip-like solid and the fibrous binder are finely and uniformly dispersed and mixed. In this case, since the chip-like solid constituting the upper layer of the fibrous binder does not exist, the uniform The degree of dispersion mixing does not reach the case of the laminate shown in FIG.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
(raw materials)
The raw material is mainly composed of a light-weight chip solid material. One of the typical embodiments is non-metallic shredder dust in which metal, glass pieces, wire harnesses and the like are excluded from shredder dust made of scrap material of a vehicle. Particularly preferable raw materials include high-quality shredder dust mainly composed of urethane and fibers extracted from vehicle waste materials.
[0021]
In this case, as a light-weight chip-like solid material, a plastic foam fragment such as urethane foam occupies a majority, and is mainly composed of other fibers. This fiber is a mixture of woven fabric fragments, fiber scraps, and the like that constitute the vehicle seat skin. In the raw material, it is allowed that a minute piece of metal, glass or the like is mixed into the raw material to the extent that it does not impair the production process of the soundproofing material and the quality of the soundproofing material product.
[0022]
Furthermore, as will be described later, the trim end material and the defective product of the soundproofing material according to the present invention can be defibrated and pulverized and reused as raw materials, or other than non-metallic shredder dust derived from vehicle waste materials. Waste materials derived from these industrial fields may be recycled as raw materials of the present invention. In some cases, chip-shaped solids may be prepared using new materials such as plastic, rubber, and wood, and these may be used as raw materials.
[0023]
The shape and size of the chip-like solid material are not limited. However, in order to improve the processing efficiency and form a preferable soundproof material, the shape is not extremely large in shape (film shape, fiber shape, etc.), the average particle diameter of the chip is about 20 mm or less, etc. More preferred.
[0024]
(Thermoplastic fibrous binder)
As the thermoplastic fibrous binder, a fibrous thermoplastic resin is usually used. A fibrous binder made of a thermoplastic material other than resin, such as thermoplastic rubber, can also be used. Further, a fibrous binder having a core-sheath structure composed of a low melting point sheath that melts when the soundproofing material is heat-molded and a high melting point core that does not melt when the soundproofing material is heat-molded can be used particularly preferably.
[0025]
The fiber form and fiber length in the fibrous binder are not limited. As examples of typical forms of fibers, there are fluffy fibers in which relatively long fibers are entangled to form a hairball, and bundled fibers in which relatively short fibers are bundled. In addition, in relation to the size of the chip-like solid matter to which the fibrous binder is to be bound, the fiber length and the average particle diameter of the chips are approximately the same because of the improvement of the mixing property and the uniformity of the soundproofing properties accompanying therewith. More preferably, the dimensions are
[0026]
For example, when manufacturing a dash silencer for automobiles in the conventional prior art, the amount of the fibrous binder Y used for the raw material X made of chip-like solids is about X: Y = 8: 2 by weight ratio, or Y is used. Although it is considered that the amount needs to be further increased, in the present invention, the fibrous binder is satisfactorily defibrated and is extremely finely dispersed and mixed with the chip-like solid. A ratio of X: Y = 9: 1 is sufficient. However, the amount of fibrous binder used is not limited.
[0027]
(Mixing process)
The mixing step is a step of mixing a raw material mainly composed of a light-weight chip-like solid and a thermoplastic fibrous binder. This step includes at least a step of preparing a laminate having a chip-like solid as upper and lower layers and the fibrous binder as an intermediate layer, and a defibrating and mixing process described later.
[0028]
As the laminated body, it is sufficient that the upper and lower layers made of a chip-like solid are formed with respect to the fibrous binder as the intermediate layer. For example, the laminated body has a three-layer sandwich structure as shown in FIG. Alternatively, a sandwich structure of five or more odd layers having the same configuration may be used. Depending on the required amount of mixing and the type of raw materials, these laminated structures can be changed.
[0029]
As a pretreatment for preparing the laminated body, the chip-like solid material supplied as a shredder dust mass is dispersed in advance by a rotating cylinder having needle-like protrusions on the peripheral surface, or the fibrous binder is removed. It is also preferable to defibrate in advance with a fiber machine, but such pretreatment is not essential.
[0030]
The method of forming the laminated body is not limited, but for example, while operating a conveying means such as a belt conveyor for feeding the laminated body to the defibrating and mixing process, first from a hopper or the like positioned on the conveying surface on the most upstream side. A lower layer is configured by supplying and depositing chip-like solids, and then an intermediate layer is configured by supplying and depositing a fibrous binder from a hopper or the like located on the downstream conveyance surface, and further It can be easily formed by a method of forming an upper layer by supplying and depositing chip-like solids from a hopper or the like located on the downstream conveyance surface.
[0031]
(Defibration mixing process)
The defibrating and mixing process is a process of scraping the laminated body of the chip-like solid matter and the fibrous binder constrained in a compressed state little by little with a scraping projection member.
[0032]
The embodiment for constraining the laminate to a compressed state is not limited as long as the object is achieved. A typical example is to feed a laminated body conveyed by appropriate conveying means between a pair of rotating rollers and to extrude while compressing. In this embodiment, since the laminated body extruded from between the rotating rollers may be scraped sequentially, the defibrating and mixing process can be performed continuously and efficiently.
[0033]
As another embodiment, for example, a pair of reciprocating pressing bodies is provided with a lateral feed mechanism, and a part of the stacked body protrudes while being constrained in a compressed state between the pressing bodies, and the protruding portion is scraped off. An intermittent method or the like that repeats the operation and the operation of releasing the part of the laminated body again by releasing the restraint of the laminated body and laterally feeding is also possible.
[0034]
The embodiment of the scraping by the scraping projection member is not limited as long as the purpose is achieved. A typical example is a system in which a laminated body constrained in a compressed state is sent to a rotating cylinder having needle-like protrusions on the peripheral surface and scraped little by little by the needle-like protrusions. When this method is combined with the above-described rotating roller feeding method, a very excellent defibrating and mixing process can be performed.
[0035]
As another embodiment, for example, a method of scraping a laminated body that is sent in a compressed state by a reciprocating (so-called reciprocating method) scraping member having a comb-like protrusion is sequentially and little by little. Is possible.
[0036]
In the defibrated and mixed material after the defibrating and mixing process, the chip-like solid material and the fibrous binder that has been finely defibrated forcibly are in a state of being extremely finely and uniformly dispersed and mixed. This may be used as it is for a temporary stock or may be immediately used for the next process for producing a soundproof material.
[0037]
(Other processes)
In the present invention, any necessary or beneficial steps such as the following (1) to (3) can be included.
[0038]
(1) A conveyance / filling process in which, after the defibrating and mixing process, the defibrated and mixed material is conveyed to a mold as a sheet or blown into the mold.
[0039]
The embodiment of the conveyance / filling process is not limited. For example, as the former, a method of depositing a defibrated mixed processing material in a sheet shape and conveying it between an upper mold and a lower mold of a hot press mold, as the latter Is preferably a method in which the defibrated and mixed material is placed in a pressurized gas and blown into a hot press mold.
[0040]
In the latter method, the blowing resistance gradually increases as the filling progresses, and as a result, there is a possibility that the uniformity of the filling density into the mold may not be ensured. It is also preferable to reduce.
[0041]
When the blow filling method into the mold is adopted, it is considered that the chip-like solid and the fibrous binder are further finely and uniformly mixed and dispersed by the gas pressure feeding process.
[0042]
(2) A molding step in which the defibrated and mixed material is heated and pressed by a molding die, the chip-shaped solids are bound to each other by a hot-melted fibrous binder, and a soundproof material having a predetermined shape is molded.
[0043]
When this molding process is performed by the blow filling method, it is divided into a molding process of a preform body that is weakly heated and a main molding process that is heated strongly, and the former avoids the complicated shape of the cavity and is simpler than the main molding. By forming a plate-shaped (for example, flat plate-shaped) preform body having a uniform shape, the uniformity of the packing density in the mold is ensured. The method of giving is also preferable.
[0044]
In order to increase the efficiency of repeated heating and cooling of the preform mold and the main mold in the molding cycle, the upper and lower molds are provided with a large number of vent holes opened on the molding surface, and these vent holes are provided in the upper and lower molds. Communicating with the heating / cooling box attached to the molding die, hot air is sent from one heating / cooling box A to the other heating / cooling box B via the mold vent during mold heating, and conversely from the heating / cooling box B during mold cooling. A method of sending cold air to the heating / cooling box A via the mold vent is also preferable.
[0045]
(3) A step of reusing the end material (or defective molding product) generated in the trim step after the molding as a raw material for the chip-like solid. In this reuse process, the above-mentioned end material is first defibrated and then shredded, so that it can be regenerated well as a raw material for chip-like solids in the present invention.
[0046]
【Example】
In the following, an embodiment of the present invention will be described based on FIG.
[0047]
The three raw material supply sites 3, 4, and 5 shown in FIG. 2 are sequentially positioned on the transport surface of the belt conveyor 6 for transporting the laminated body from the upstream side to the downstream side in the transport direction. The conveyor belts 3a, 4a, 5a, a pair of rotating cylinders 3b, 4b, 5b having needle-like projections, and hoppers 3c, 4c, 5c are provided.
[0048]
The upstream raw material supply site 3 and the downstream raw material supply site 5 contain non-metallic shredder dust (made of plastic foam material, non-foam plastic material, rubber material fragments, etc.) having an average particle size of about 5 mm. The aggregate 7 is supplied, and the intermediate raw material supply site 4 is supplied with an aggregate 8 of an undefined fibrous binder composed of polyester short fibers having a core-sheath structure with an average fiber length of 10 mm.
[0049]
In this example, the ratio of the total supply amount of the non-metallic shredder dust aggregate 7 (X) and the supply amount of the fibrous binder aggregate 8 (Y) is X: Y = 9: About 1
[0050]
These aggregates 7 and 8 are sent to the rotary cylinders 3b, 4b and 5b by the conveyor belts 3a, 4a and 5a, respectively. Then, the shredder dust aggregates 7 are loosened (dispersed in individual chip-like solids), and the undefibrated aggregates 8 are defibrated and supplied to the hoppers 3c, 4c, 5c, respectively. The lower layer 9a, the intermediate layer 9b, and the upper layer 9c are sequentially deposited on the conveying surface of the belt conveyor 6 to form a three-layer laminate 9.
[0051]
Next, the laminated body 9 is sent between a pair of rotating rollers 10 and 10 that rotate synchronously (so-called rotation) by the belt conveyor 6. Since the clearance between the pair of rotating rollers 10 and 10 is set to be considerably smaller than the stacking thickness of the stacked body 9 on the belt conveyor 6, the stacked body 9 when passing between the rotating rollers 10 and 10 is the rotating roller 10. , 10 in a compressed state.
[0052]
A rotating cylinder 11 having a large number of needle-like projections on the peripheral surface is installed immediately adjacent to the feeding direction by the rotating rollers 10 and 10 with almost no gap, and is rotated in the direction of the arrow in the figure. .
[0053]
For this reason, the laminate 9 constrained in the compressed state is scraped little by little by the needle-like protrusions of the rotating cylinder 11 immediately after passing between the rotary rollers 10 and 10 in a state where the restraint has not yet been released. Go.
[0054]
At this time, the fibrous binder of the intermediate layer 9b is forcibly shredded and scraped in a finely defibrated state, and at the same time, the chip-like solids of the upper and lower layers 9a and 9c are scraped little by little. Therefore, a fibrous binder that has been defibrated to individual chip-like solids is settled. Accordingly, in the defibrated mixed processing material 12 that is scraped and accumulated downward, the chip-like solid 1 and the fibrillated binder 2 are very fine and uniform as shown in FIG. Dispersed and mixed.
[0055]
In the above process, the defibrating and mixing process is performed by adjusting the thickness of the laminate 9 on the belt conveyor 6, the feed speed of the belt conveyor 6, the rotational speed of the rotating rollers 10 and 10, or the rotational speed of the rotating cylinder 11. The “mixed state of extremely fine and uniform dispersion” between the chip-like solid 1 and the fibrous binder 2 in the material 12 can be arbitrarily and variously adjusted.
[0056]
The defibrating and mixing treatment material 12 is temporarily accumulated in the accumulation tank 13, and then controlled by appropriate supply amount control means (not shown) provided in the accumulation tank 13, for example, and the necessary amounts are sent to the molding apparatus. , Used for the conveyance / filling process and the molding process.
[0057]
The forming apparatus includes a blower 14 connected to the accumulation tank 13, a main duct 15 following the blower 14, two branch ducts 17 and 18 branched from the main duct 15 via a switching valve 16, and branch ducts 17 and 18. Two molding sites 19 and 20 provided at the ends (the molding site 20 has the same configuration as the molding site 19, and illustration and detailed description thereof are omitted) and connected to the switching valve 16 by a duct. It consists of a cold and hot air delivery machine 21.
[0058]
Although detailed illustration is omitted at the molding site 19, a preform mold 22 having a simpler molding surface than the main molding and a main mold 23 having a molding surface corresponding to the actual shape of the soundproofing material are provided. Are sequentially provided along the line direction.
[0059]
Each of the preform mold 22 and the main mold 23 is composed of an upper mold and a lower mold that can be opened, and both upper and lower molds are freely ventilated between the heating / cooling box attached to the mold and the molding surface. It has a large number of ventilation holes. Furthermore, the periphery of the side surfaces of the upper mold and the lower mold is surrounded by a metal mesh plate covering the mold opening space, so that the defibrating and mixing treatment material 12 is stopped in the mold and air is released. The upper and lower mold surfaces may be formed of a mesh plate.
[0060]
In general, when a soundproofing material with complicated irregularities is blown and molded, the cavity also becomes a complex refracted space, so that a large number of air pools are created in the cavity, and both the width direction and the thickness direction are defibrated. It is difficult to fill the mixed material with a uniform density.
[0061]
However, a preform-shaped molded body 24 having a simpler plate shape than the main molding is once formed by the preform molding die 22 under relatively low heat compression, and this is then brought into the main molding die 23 and necessary heat compression. Such a problem can be solved by molding the molded body under the above.
[0062]
Furthermore, when blowing the defibrated and mixed processing material into the preform mold 22, the blowing air volume is gradually reduced in response to the blowing resistance gradually increasing as the filling proceeds, resulting in the blowing resistance. Is maintained at a certain level, the uniformity of the filling density of the defibrated and mixed processing material into the preform mold 22 can be ensured more satisfactorily, and a higher quality soundproofing material can be manufactured.
[0063]
Note that the defibrated and mixed treatment material is gas-fed by the action of the blower 14 and blown into one of the two molding sites 19 and 20 via the switching valve 16. Therefore, for example, when preform molding and main molding are performed at the molding site 19, it is possible to blow the defibrated mixed processing material into the preform molding die 22 at the other molding site 20.
[0064]
In this way, while effectively using the switching valve 16, the idle time of the mold is reduced and the molding cycle is improved by repeating the conveying / filling process and the molding process in a plurality of molding dies at the same time with different process phases. Can be made.
[0065]
The preform molded body 24 is subjected to molding and solidification corresponding to the shape of the actual soundproofing material under the heat compression necessary for the main mold 23, and is trimmed as a main mold 25 by a trim mold (not shown). It is divided into a soundproof material 26 and a trim end material 27. Trimming can also be performed simultaneously with the hot press molding in the main mold 23, thereby further improving the production efficiency.
[0066]
The trim end material 27 is put into the regeneration site 28, and the fibrous binder to which the chip-like solid material is bound is disentangled by a pair of rotating cylinders 29 having needle-like protrusions, and then a shredder 30 illustrated in a simplified manner. And can be reused as a good chip-shaped solid raw material by restoring the chip-shaped solid having an average particle diameter of, for example, about 5 mm. However, even if the trim end material 27 is put into a shredder without being defibrated at the regeneration site 28, it does not become a good chip-like solid raw material.
[0067]
In addition, a defective soundproofing material that may occur in the manufacturing process can be reused as a good chip-like solid raw material by the same processing as that for the trim end material 27.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a state of an aggregate before and after a defibrating and mixing process.
FIG. 2 is a diagram showing a flow of steps of an embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Chip-like solid substance 2 Fibrous binder 3,4,5 Raw material supply site 6 Belt conveyor 7,8 Aggregate 9 Laminated body 10 Rotating roller 11 Rotating cylinder 12 Disentanglement processing material 19,20 Molding site 22 Preform molding die 23 Main mold 24 Preform molded body 25 Main molded body 27 Trim end material 28 Reproduction site

Claims (1)

A mixing step of mixing a raw material mainly composed of a light-weight chip-like solid and a thermoplastic fibrous binder to form a treatment material, and heating and pressing the treatment material to thermally melt the fibrous binder to form the chip shape. In a method of manufacturing a soundproofing material including a molding step of binding solids to each other and performing press molding of the soundproofing material,
The mixing step is carried out by a scraping protrusion member installed in the feeding direction of the laminate , while constraining the laminate having the chip-like solids as upper and lower layers and the fibrous binder as an intermediate layer in a compressed state. A method for producing a soundproofing material, comprising scraping and defibrating mixing treatment.

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