JP2001060092A - Production of sound insulating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an excellent quality sound insulating material by using a shredder dust or the like by blowing/packing the shredder dust into a preform die to carry out the preform forming and then transferring the preform formed body to a normal forming die to carry out the normal forming of the sound insulating material by a hot press. SOLUTION: A preform forming die 20 having a shape of die surface simpler than that of the normal forming and a normal forming die 21 having a die surface corresponding to a shape of an actual sound insulating material are installed sequentially along the line direction while interposing an adequate transferring means of the preform formed body 24 at the forming site 17. A blowing resistance sensor is installed at the die 20. The blowing air volume from a blower 12 is gradually reduced correspondingly to the increase of the blowing resistance. This production method comprises blowing/packing the shredder dust into the die 20 to carry out the preform forming and then transferring the body 24 to the die 21 to carry out the normal forming of the sound insulating material by the hot press.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a soundproofing material, and more particularly, to a molding die for a processing material which is a mixture of a raw material mainly composed of light-weight solid chips and a thermoplastic fibrous binder. The present invention relates to a method for manufacturing a soundproofing material, which comprises blowing into the inside and forming the soundproofing material by a hot press.

[0002] The present invention relates to a soundproofing material for recycling non-metallic shredder dust made of, for example, vehicle waste material as a raw material in terms of raw materials, and a vehicle application such as a dash silencer and a floor silencer in terms of application. It is particularly preferably applied to a soundproofing material used for, for example.

[0003]

2. Description of the Related Art One of the leading technologies for producing soundproofing materials such as dash silencers and floor silencers for automobiles having low bulk density and excellent soundproofing and vibrationproofing performance is one of the promising technologies for manufacturing light-weight solid chips. There is a method in which a raw material and a thermoplastic fibrous binder are mixed and introduced into a hot press-type forming die to press-mold a soundproofing material.

[0004] In this case, in particular, when the non-metallic shredder dust extracted from the scrap of the vehicle is effectively used as the light-weight chip-like solid material, it is economical and also from the viewpoint of material recycling. It is significant.

In such a soundproofing material manufacturing technique, as a typical method of introducing the mixture (processing material) into a molding die, for example, as shown in JP-A-8-112584, the processing material is deposited in a sheet shape. There is a method in which the molding material is carried between the upper mold and the lower mold, and a method in which the processing material is blown into the molding die. The latter method is considered to be advantageous from the viewpoint of high production efficiency. .

[0006]

By the way, soundproofing materials such as dash silencers and floor silencers for automobiles are generally thin plate-shaped and have many bent portions. The cavity shape in the mold also has a thin plate shape with many bent cross-sectional shapes. On the other hand, the processing material to be filled is a non-metallic shredder dust such as a soft urethane foam, or a bulky material having a large compressive deformation property mainly composed of a fibrous binder or the like.

For this reason, conventionally, when the processing material is blown into the molding die, a large number of air pools are generated in the molding die cavity, and the processing material is easily caught and retained at a portion having a particularly bent cross-sectional shape. The following problems have occurred. Since it is necessary to fill the entire cavity with the processing material against the above-described stagnation phenomenon, the processing material blowing step requires a relatively long time, and the molding cycle time has been long. The packing density of the processing material becomes uneven between the part where the processing material easily stagnates in the cavity and the part where it does not, and the strength and soundproofing properties of the soundproofing material after molding are uneven in each part. It was easy to happen. The above problems are caused by a thin and wide cavity shape with a bent cross-sectional shape. To avoid these problems as much as possible, the degree of freedom in designing sound-insulating materials, especially for thin-walled parts, is limited. It was quite constrained.

Accordingly, the present invention relates to a method for producing a soundproofing material, comprising blowing a treatment material comprising a mixture of a light-weight chip-like solid material and a fibrous binder into a molding die and forming the soundproofing material by a hot press. Resolving the above problems is an issue to be solved.

[0009]

(Structure of the First Invention) The structure of the first invention of the present application (the invention of the first aspect) for solving the above-mentioned problems mainly consists of a chip-shaped solid material of a lightweight material. In a method for manufacturing a soundproofing material, a processing material which is a mixture of a raw material and a thermoplastic fibrous binder is blown and filled into a molding die, and further molded into a soundproofing material shape by a hot press. Performing preform molding by blowing and filling into a preform mold having a molding surface of a simpler shape, and then moving the preform molded body to a main mold having a molding surface corresponding to the soundproofing material shape,
This is a method for producing a soundproofing material, in which the soundproofing material is fully formed by a heating press.

(Structure of the Second Invention) The structure of the second invention (the invention described in claim 2) for solving the above-mentioned problem is as follows.
This is a method for producing a soundproofing material, in which the preform of the first invention is subjected to light heat pressing to impart integrity to the preform.

[0011]

The operation and effect of the present invention (the operation and effect of the first invention) The cavity shape in the preform mold having a molding surface having a simpler shape than the main molding (for example, a flat shape or a shape close thereto) is a thin plate shape. However, it does not involve a bent cross-sectional shape. Therefore, when the processing material is blown and filled into the preform mold, no air pool is generated in the cavity,
The treatment material does not stay in the curved cross-sectional shape portion in the cavity.

As a result, with respect to the above-mentioned problems, the processing material blowing step is performed quickly and smoothly, and the molding cycle time is shortened. Regarding the above-mentioned problem, the filling density of the processing material becomes uniform because there is no portion where the processing material easily stays in the cavity,
As a result, it is possible to manufacture an excellent soundproofing material having uniform strength and soundproofing properties in each part. In addition, from the above points, regarding the above-mentioned inconvenience, especially including a part designed to be thin,
The degree of freedom in designing soundproofing materials is improved. (Function / Effect of the Second Invention) In the second invention, in a preform molded article which has been subjected to mild heat pressing, chip-like solids are slightly bound to each other by a slight thermal fusion of a fibrous binder, and The reformed molded article is provided with a certain degree of integrity enough to withstand the movement between the molds. Therefore, when the preform molding is transferred from the preform molding die to the main molding die by an appropriate means, it is easy to maintain its shape, in other words, it is easy to arbitrarily design the transition means of the preform molding.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION (Raw materials) Raw materials are mainly composed of light-weight solid chips. One of the representative embodiments is a nonmetallic shredder dust in which metal, glass pieces, wire harnesses, and the like are excluded from shredder dust made of vehicle waste. Particularly preferred raw materials include high-quality shredder dust mainly composed of urethane and fibers extracted from vehicle scraps.

As the light-weight solid chips, plastic foams such as urethane foams occupy the majority and are mainly composed of other fibers. The fiber is a mixture of a piece of woven fabric, fiber waste, and the like, which have constituted the seat skin of the vehicle. As long as the production process of the soundproofing material and the quality of the product are not impaired, small fragments of metal, glass, and the like may be slightly mixed in the raw material.

Furthermore, as will be described later, trimmed scraps or defective products of the soundproofing material according to the present invention can be reused as raw materials, and non-metallic shredder dust derived from vehicle scrap can be reused. In addition to the above, waste materials derived from other industrial fields may be recycled as raw materials of the present invention. In some cases, chip-like solids are prepared using new materials such as plastic, rubber, and wood, and this is used as a raw material. Is also good.

(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 the resin, for example, a thermoplastic rubber or the like can also be used. Further, a fibrous binder having a core-sheath structure composed of a low melting point sheath portion which is melted during heat molding of the soundproofing material and a high melting point core portion which is not melted during heatforming of the soundproofing material can be particularly preferably used.

The form and length of the fibers in the fibrous binder are not limited. In relation to the size of the chip-like solid matter to be bound by the fibrous binder, the fiber length and the average particle diameter of the chip are of the same size because of the improvement of the mixing property and the resulting uniformity of the soundproofing properties. That it is,
More preferred. The amount of the fibrous binder Y to be used with respect to the raw material X composed of the solid chips is not limited, but may be, for example, about X: Y = 8: 2 to 9: 1 by weight.

(Mixing of Chip Solid and Fibrous Binder) The step of mixing the chip solid and the fibrous binder into a treatment material can be performed using any known mixing apparatus. .

However, a particularly preferred method is to scrape a coarse mixture or laminate of a chip-like solid and a fibrous binder constrained in a compressed state, for example, using a rotating cylinder having needle-like projections on its peripheral surface. This is a method of mixing by a fibrillation mixing process of scraping a small amount by a projection member. In particular, it is preferable to use a method in which a chip-like solid is used as an upper and lower layer and a fibrous binder is used as an intermediate layer, and the laminate is restrained in a compressed state and scraped little by little. In the case of using these methods, the chip-shaped solid and the fibrous binder forcibly finely defibrated are extremely finely and uniformly dispersed and mixed. Bound more uniformly and well.

The processing material mixed as described above is first subjected to preform molding as a pretreatment for the main molding in a preform molding die, and then carried into the main molding die and subjected to a hot press as described below. In this way, the desired shape of the soundproofing material is finally formed.

(Preform Mold and Blow-Fill) The treatment material is blow-filled into a preform mold provided upstream of the main mold line. At this time, the mixed treatment material may be immediately blown into the preform mold, or may be temporarily accumulated in a hopper or the like, and then the required amount may be supplied to the blow filling. A supply port such as a hopper may be provided with a supply port opening degree adjusting mechanism capable of adjusting the supply amount of the processing material.

The preform mold is composed of an upper mold and a lower mold, and can be pressed and opened, and the molding surfaces of the upper and lower molds have a simpler shape than the main molding (for example, a flat surface). Or a shape close to this). However, these molding surfaces may have relatively slow concave portions and convex portions for setting a thick portion or a thin portion (not a bent cross-sectional shape portion) in the preform molded body.

The configuration of the preform mold is not limited as long as such a condition is satisfied, but generally, as shown in the examples, a specific portion (usually, a central portion of the upper mold) is provided with air. Is provided, and the periphery of the side of the mold is surrounded by a mesh plate so as to cover the mold opening space, so that the processing material is stopped in the mold and the blown air is released from the mesh plate. The molding surfaces of the upper and lower dies may be constituted by mesh plates.

As in the second aspect of the present invention, it is preferable that the preform mold is provided with a heating / cooling function so that a light heating press can be performed on the filled processing material. The heating press in this case, the preform molded body,
It is preferable that the process is performed to such an extent as to provide the integrity that allows the transition from the preform molding die to the main molding die while maintaining the shape, and not to impair the degree of freedom of the shape processing in the main molding.

The treatment material is blown and filled into the preform mold by, for example, a method in which the treatment material is put on a pressurized gas generated by a blower such as a blower and blown into the mold. Because the upper and lower molding surfaces of the preform mold are simple shapes,
The processing material is rapidly and smoothly filled from the portion near the air vent portion toward the portion near the blow port.

The blowing resistance gradually increases with the progress of filling of the processing material. At this time, the processing material blocks the transmission of the filling pressure to the end of the cavity due to the compression deformation caused by the increase of the blowing resistance. However, as a result, there is a concern that a problem that the filling density of the processing material is increased toward the center of the cavity. To cope with this, it is effective to control the amount of air blown into the preform mold so as to be reduced in accordance with an increase in blowing resistance.

Various methods can be used to control the blown air flow. (1) An increase in the blown air resistance is detected with an appropriate sensor over time, and the blown air flow is adjusted based on the detected value. A method of performing feedback control of the means, or (2) standard data of an increase value of the blowing resistance over time in the embodiment under the same conditions and a reduction value of the blowing air amount corresponding to this value are acquired in advance. In particular, a method of anticipating and controlling the adjusting means based on this data is particularly preferable.

(Main Mold) The main mold is installed downstream of the preform mold with respect to the line, and means for transferring the preform is provided between the two. The type of the transfer means is arbitrary, and may be, for example, a driven belt conveyor, a roller conveyor, or the like. However, in order to maintain the shape of the preform molded body at the time of the transfer, the preform molding is preferably performed. Means such as a retractable clamp that grips and retracts the distal portion of the body into the molded body are more preferred. The driven conveyor and the traction clamp may be used together. Since the preform molded body is provided with a certain degree of integrity, it can follow such a transition operation while maintaining its shape.

This molding die is composed of an upper die and a lower die. The molding die is capable of at least hot pressing and opening, and the molding surfaces of the upper and lower dies have a predetermined complicated shape corresponding to the shape of the soundproofing material. It has.

The type of the heating / cooling mechanism of the present mold is not limited, but in order to shorten the molding cycle, a mechanism capable of forcibly performing heating and subsequent cooling is preferable. In particular, since the object to be molded is a gas-permeable material, the upper and lower molds are provided with a large number of ventilation holes opened in the molding surface, and these ventilation holes are provided in the upper and lower molding dies, respectively. It communicates with the cooling boxes A and B, and sends hot air from the heating / cooling box A to the heating / cooling box B via the mold air hole when heating the mold, and conversely, from the heating / cooling box B via the mold air hole when cooling the mold. A method of rapidly heating and cooling the processing material and the mold by a method of sending cold air to the heating / cooling box A is preferable. When the preform mold is provided with a heating / cooling function, it is preferable to adopt the same configuration.

(Structure of molding line) As a line structure of these molding dies, one preform molding die and one main molding die may be arranged for one processing material blowing device. A plurality of preform forming dies-a main forming die line is arranged in a branching mold with respect to the processing material blowing device, and a preform forming die in one forming line is filled with the processing material. In another molding die line, a system with high production efficiency, in which preform molding of a processing material already filled can be performed.

(Other Steps) The soundproofing material that has passed through the above-described molding step is then finished in a trimming step of cutting off offcuts. Trim scraps (or moldings that happen to occur) that are generated in this step can be satisfactorily regenerated as raw materials for chip-like solids in the present invention by first defibrating and then shredding.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 1 which conceptually illustrates an example of a process flow.

The three raw material supply sites 1, 2, 2 shown in FIG.
Numerals 3 are sequentially positioned on the conveying surface of a belt conveyor 4 for forming and conveying the laminated body from the upstream side to the downstream side in the conveying direction, and both are arranged on the conveying belts 1a, 2
a, 3a and a pair of rotary cylinders 1b,
2b, 3b and hoppers 1c, 2c, 3c.

The upstream material supply site 1 and the downstream material supply site 3 are made of non-metallic shredder dust (plastic foam material, non-foam plastic material, fiber fragments, etc.) having an average particle size of about 5 mm. 5) is supplied, and an unfibrillated fibrous binder aggregate 6 made of polyester short fibers having a core-sheath structure having an average fiber length of 10 mm is supplied to the intermediate raw material supply site 4.

In this embodiment, the ratio of the total supply amount of the nonmetallic shredder dust aggregate 5 (X) to the supply amount of the fibrous binder aggregate 6 (Y) is represented by X:
Y = about 9: 1.

These assemblies 5 and 6 are rotated by the transport belts 1a, 2a and 3a, respectively.
2b, 3b, where the aggregate 5 of shredder dust is loosened (disintegrated into individual chip-like solids),
Further, the aggregate 6 in the unfibrillated state is coarsely defibrated, supplied to the hoppers 1c, 2c, and 3c, respectively, and sequentially deposited on the conveying surface of the belt conveyor 4, thereby forming a three-layer laminate 7. .

Next, the stacked body 7 is fed by a belt conveyor 4 between a pair of rotating rollers 8, which are synchronously rotated (so-called corotating). Since the clearance between the pair of rotating rollers 8, 8 is set to be considerably smaller than the stacked thickness of the stacked body 7, the stacked body 7 when passing between the rotating rollers 8, 8 is restrained in a compressed state.

A rotary cylinder 9 having a large number of needle-like projections on its peripheral surface is installed immediately adjacent to the feed direction by the rotary rollers 8 and 8 with almost no gap, and rotates in the direction of the arrow in the figure. are doing. Therefore, the laminate 7
Immediately after passing between the rotating rollers 8, in a state where the restraint has not been released, the needle-like projections of the rotating cylinder 9 sequentially scrape the small pieces. Therefore, since the fibrous binder in the intermediate layer is forcibly cut into small pieces by small amounts and scraped in a finely defibrated state, the chip solids in the upper and lower layers are also scraped little by little. In the defibration-mixed processing material 10 in which the fibrillated binder that has been defibrated with the object is collected and scraped off and accumulated below, the chip-shaped solid material and the defibrated fibrous binder are extremely finely divided. And they are uniformly dispersed and mixed.

The defibrated mixed material 10 is temporarily accumulated in the accumulation tank 11 and then, for example, when the blowing air volume is large or small,
The required amount is controlled by an appropriate supply amount control means (not shown) such as an on-off valve provided in 1, and the required amount is sent to the molding device and supplied to the filling step and the molding step.

The molding apparatus includes a blower 12 connected to the collecting tank 11, a main duct 13 following the blower 12, two branch ducts 15, 16 branched from the main duct 13 via a switching valve 14, a branch duct 15, A duct is provided for each of two molding sites 17 and 18 provided at each end of 16 (the molding site 18 has the same configuration as the molding site 17 and is not shown and described in detail) and the switching valve 14. It consists of a connected hot / cold air delivery device 19.

At the molding site 17, a preform molding die 20 having a molding surface having a simpler shape than the main molding, and a main molding die 2 having a molding surface corresponding to the shape of the actual soundproofing material.
1 are sequentially provided along the line direction via an appropriate transition means (refer to the above) of the preform molded body 24.

Each of the preform mold 20 and the main mold 21 comprises an upper mold and a lower mold that can be opened and press-molded. As shown in FIG. 2, in the preform molding die 20, a blow port (not shown) is provided in an upper die 22a through which the branch ducts 15 and 16 are communicated, and side surfaces of an upper die 22a and a lower die 22b are further provided. The surrounding area is a metal mesh plate 23 that covers the mold opening space.
To stop the defibration / mixing material 10 in the mold and allow air to escape. The molding surfaces of the upper mold 22a and the lower mold 22b may also be mesh plates.

Next, as shown in FIG.
Are formed on the upper mold 21a and the lower mold 21b, respectively.
It has a large number of ventilation holes 21c opened to 1d. These ventilation holes 21c communicate with heating and cooling boxes A and B attached to the upper mold 21a and the lower mold 21b, respectively. Although not shown, the preform mold 20 also has a similar heating and cooling function.

During heating, hot air is sent from the heating / cooling box A to the heating / cooling box B through the vent 21c and through the defibration / mixing material to be molded. Then, the processing material and / or the mold are quickly heated and cooled by a method of sending cold air to the heating / cooling box A in the reverse route.

The heating press in the preform mold 20 is relatively light, that is, the chip-like solids are slightly bonded to each other by a slight thermal fusion of the fibrous binder.
The process is performed to such an extent that the preform molded body 24 is given a certain degree of integrity that can withstand the operation of moving between the dies.
On the other hand, in the main mold 20, the main molded body 25 is formed with sufficient press pressure and heating.

Next, at an appropriate portion of the preform mold 20, a blowing resistance sensor (not shown) for sensing an increase in blowing resistance as the blowing and filling of the defibration / mixing material proceeds is provided. The blow-in resistance value thus fed back is fed back to the blower 12, so that the blow-off air volume from the blower 12 is gradually reduced in accordance with the increase in the blow-in resistance.

As a result, the blowing resistance is maintained at a constant level, and even if the blowing resistance gradually increases, the uniformity of the packing density of the defibrated mixed processing material into the preform mold 20 is ensured.

The defibrated mixed material is gas-fed by the action of the blower 12 and blown into one of the two molding sites 17 and 18 via the switching valve 14. Therefore,
For example, when the preform molding and the main molding are performed at the molding site 17, the defibration mixed material can be blown into the preform molding die 22 at the other molding site 18.

Thus, while effectively using the switching valve 14,
By repeating the transport / filling step and the molding step in a plurality of molding dies in different process phases at the same time, the play time of the molding dies can be reduced and the molding cycle can be improved.

The preform molded body 24 is a
Undergoes molding and solidification corresponding to the actual shape of the soundproofing material under the necessary heating and compression, and is trimmed as a main molded body 25 by a trim mold (not shown) to be divided into a soundproofing material 26 and a trim end material 27. . In addition, it is also possible to perform trimming at the same time as press forming in the main mold 21, thereby further improving the manufacturing efficiency.

The trim end material 27 is put into a reproduction site 28, and a pair of rotary cylinders 29 having needle-like projections is used to defibrate the fibrous binder binding the chip-like solids. Into the shredder 30
For example, by restoring to a chip-like solid having an average particle size of about 5 mm, it can be reused as a good chip-like solid material. However, even if the trim ends 27 are put into a shredder without being defibrated at the reproduction site 28, they do not become a good chip-like solid material.

In addition, a defective soundproofing material which may be generated in the above manufacturing process can be reused as a good chip-like solid material raw material by the above-described processing similar to the trim end piece 27.

[Brief description of the drawings]

FIG. 1 is a diagram showing a flow of steps in an embodiment.

FIG. 2 is a view showing a configuration of a blow mold according to an embodiment.

FIG. 3 is a cross-sectional view illustrating a configuration of a main mold according to an embodiment.

[Explanation of symbols]

 1, 2, 3 Raw material supply site 4 Belt conveyor 5, 6 Aggregate 7 Laminate 10 Fibrillation mixed processing material 17, 18 Molding site 20 Preform molding die 21 Main molding die 21a, 22a Upper die 21b, 22b Lower die 21c Vent holes A, B Heating / cooling box 24 Preform molded body 25 Main molded body 27 Trim offcuts 28 Regeneration site

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Naka Takashi 1-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Boshoku Corporation (72) Inventor Junichi Hishida 1-1-1, Toyota-cho, Kariya-shi, Aichi prefecture Inside (72) Inventor Masaru Suzuki 1-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Boshoku Corporation (72) Inventor Tetsuyasu Akita 1-1-1, Toyota-cho, Kariya-shi, Aichi prefecture Inside Toyota Boshoku Corporation ( 72) Inventor Ikuji Tsujida 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Takuji Kajiwara 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F term (reference) 4F301 AA29 BA21 BB06 BE11 BE31 BE45 BF25 BF31 5D061 AA07 AA22 BB37 DD11

Claims (2)

[Claims] 1. A processing material, which is a mixture of a raw material mainly composed of light-weight solid chips and a thermoplastic fibrous binder, is blown and filled into a molding die, and further formed into a soundproofing material by a hot press. In the method of manufacturing a soundproofing material to be molded, the treatment material is blown and filled into a preform mold having a molding surface with a simpler shape than the main molding to perform preform molding, and then the preform molded body corresponds to the shape of the soundproofing material. A method for producing a soundproofing material, characterized by transferring the soundproofing material to a full-forming mold having a formed molding surface and performing a main molding of the soundproofing material by a hot press. 2. The method for producing a soundproofing material according to claim 1, wherein, during the preform molding, light heat pressing is performed to impart integrity to the preform molded body.