JP2930176B2 - Molded felt and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded felt suitable as a material of a sound absorbing material installed in a vehicle and a method of manufacturing the felt.

[0002]

2. Description of the Related Art For example, as shown in FIG. 8, a dash panel 1 defining an engine room E and a vehicle room R has a dash panel 1 on the side of the vehicle room where noise is transmitted from the engine room E into the vehicle room R. To prevent this, an insulator dash 2 is provided.

[0003] The insulator dash 2
Is a PVC sheet mixed with a filler, as shown in FIG.
A two-layer structure having a sound insulating material layer 3 such as a rubber sheet and a sound absorbing material layer 4 made of a porous base material such as felt is generally used.

The sound absorbing material layer 4 absorbs noise from the engine room E, and the double wall sound insulating effect between the dash panel 1 and the sound insulating material layer 3 provides a good sound absorbing effect in addition to the sound absorbing effect. It is designed to achieve soundproofing characteristics.

By the way, as the sound absorbing material layer 4, there is a tendency to use a molded felt which is formed into a desired curved shape by cold press molding after preheating so as to correspond to a complicated panel shape.

[0006] The method of manufacturing the molded felt will be described with reference to the process chart shown in Fig. 10. The raw material mat is prepared by mixing a thermosetting resin and a thermoplastic resin into fleece-like raw cotton such as cotton yarn and synthetic fiber. A raw mat forming step for forming a raw mat and placing the raw mat in a heating furnace, curing a part of the thermosetting resin in the raw mat, and melting a part of the thermoplastic resin as a binder It is manufactured from a heat treatment step for functioning, and a cooling step for cooling and then solidifying the thermoplastic resin in the raw mat.

An outline of this manufacturing method is shown in FIG. 11, in which a raw mat M in which a thermosetting resin and a thermoplastic resin are mixed in fleece raw cotton is formed.

The mixing ratio of the raw cotton, the thermosetting resin and the thermoplastic resin is 15 parts by weight of the thermosetting resin and 15 parts by weight of the thermoplastic resin with respect to 70 parts by weight of the raw cotton.

Then, the raw mat M is conveyed to the heating furnace 6 by the conveyor 5. When the raw mat M is conveyed by the net-type conveyor 6a in the heating furnace 6, hot air is blown and the temperature in the heating furnace 6 is adjusted to 150 to 230 ° C. The part is hardened to secure the bulkiness of the molded felt F, and a part of the thermoplastic resin is melted, conveyed to the vacuum device 7 and cooled, and the molded felt F is manufactured.

[0010] The formed felt F is cut into a predetermined size to be used as a material of the insulator dash 2.

[0011]

As described above, in the conventional molded felt F, the thermoplastic resin mixed in the mat functions as a binder and maintains a desired bonding force between the fibers. Usually, the formed felt F is preheated and softened, and then formed into a required shape by cold press molding. However, when the formed felt F is preheated and softened, the thermoplastic resin inside the mat melts to bond the fibers. It is pointed out that the forming force F is weakened, the formed felt F is easily cut or shredded, and the handling characteristics are poor.

Further, a conventional molded felt F is shown in FIG.
As shown in the enlarged view, the surface side is fluffy, the fiber on the surface side scatters during handling, worsens the working environment at the time of mounting work, and penetrating parts such as harnesses when applied to sound absorbing materials for vehicles At the time of assembling, it has been pointed out that the fiber is easily caught and the sound absorbing material is liable to be frayed or cut.

The present invention has been made in view of such circumstances, and a molded felt suitable as a material of a sound absorbing material layer such as an insulator dash for an automobile and a method of manufacturing the felt have excellent handling characteristics, and have been cut and cut. It is an object of the present invention to provide a molded felt which does not cause any problem and a method for producing the felt.

[0014]

In order to achieve the above-mentioned object, the present invention provides at least one of a mat in which a thermosetting resin or a thermoplastic resin is mixed as a binder in fleece-like raw cotton made of cotton yarn, synthetic fiber, or the like. A resin layer obtained by curing a thermosetting resin and melting and solidifying a thermoplastic resin is formed on the side surface.

The composition of the mat is as follows: cotton yarn,
Use fleece-like raw cotton in which natural fibers, chemical fibers, fiber waste, etc. are spread, and the mixing ratio of resin in the mat is 6
The total amount of the thermosetting resin and the thermoplastic resin is 40 to 15 parts by weight based on 0 to 85 parts by weight.

The compounding ratio of the thermosetting resin and the thermoplastic resin may be set between 70 and 30 parts by weight of the thermoplastic resin with respect to 30 to 70 parts by weight of the thermosetting resin.

The thermosetting resin may be appropriately selected from phenol resins, melamine resins, urea resins and the like, and phenol resins are preferred in terms of cost.

On the other hand, the melting point of the thermoplastic resin is 10
Those at around 0 ° C. are preferred, and polyethylene resins are preferred.

Furthermore, the method for producing the molded felt is as follows:
A thermosetting resin and a thermoplastic resin are mixed at an appropriate mixing ratio in a fleece-like raw cotton such as cotton yarn and synthetic fiber to form a raw mat, and then the raw mat is heated in a heating furnace, and the inner mat is heated. A part of the thermosetting resin is cured, and a part of the thermoplastic resin is melted.After a cooling step, a mat forming step for forming the mat and a reheating treatment on at least one side surface of the mat are performed, and the cooling is performed. A mat surface treatment step of forming a resin layer obtained by curing a thermoplastic resin and a thermosetting resin on at least one surface of the mat through a process.

The heating furnace in the heat treatment step is
The temperature is adjusted to 0 to 230 ° C, preferably 180 to 210 ° C.

The conveyor in the heating furnace may be a net-type conveyor or an iron plate-type conveyor. Since the net-type conveyor transmits heat to the inside of the mat and has better thermal efficiency, the length of the conveyor is smaller than that of the net. In case of type conveyor 1
0 to 15 m, and 30 m or more in the case of an iron plate type conveyor.

In the reheating treatment step, a pair of heating rolls or a heating conveyor may be used, and the heating temperature is 130 to 230 ° C, preferably around 200 ° C.

The thermoplastic resin may be granular, powdery or fibrous.

[0024]

As apparent from the above constitution, the molded felt according to the present invention has a resin layer formed on at least one surface of the mat, and when the molded felt is preheated and softened, the thermoplastic resin inside the mat is reduced. Even if the resin melts and the inter-fiber bonding force decreases, the formed felt is hardly cut due to the restraining action of the resin layer, and the handling characteristics are improved.

Further, since the resin layer is formed on at least one surface of the mat, fibers on the surface side are not scattered. No breakage of the sound absorbing material or fraying of the fibers due to the fibers being hooked on the mating part.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a molded felt according to the present invention and a method for producing the same will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view showing an insulator dash for an automobile manufactured by using the molded felt according to the present invention, FIG. 2 is a sectional view showing an embodiment of the molded felt according to the present invention, and FIG. FIG. 4 is a process chart diagram in the felt manufacturing method, and FIG. 4 is a schematic view showing one embodiment of the felt manufacturing method.

FIG. 5 is a sectional view showing the configuration of another embodiment of the molded felt according to the present invention, FIG. 6 is an explanatory view showing a reheating treatment step in the manufacturing process of the molded felt of FIG. 5, and FIG. It is principal part sectional drawing of the insulator dash to which the molding felt shown in FIG.

In FIG. 1, an insulator dash 10 for a vehicle comprises a sound insulating material layer 11 such as a PVC sheet or a rubber sheet mixed with a filler, and a sound absorbing material layer 12 integrally attached to the back side of the sound insulating material layer 11. And is attached and fixed on the indoor side surface of the dash panel 13.

Next, FIG. 2 is a cross-sectional view showing the structure of the molded felt 20 according to the present invention used as a material of the sound absorbing material layer 12. The molded felt 20 according to the present invention is applied to fleece-like raw cotton such as cotton yarn and synthetic fiber. A resin layer 40 is integrated on the front and back sides of a mat 30 formed by mixing a thermosetting resin and a thermoplastic resin at an appropriate mixing ratio.

The mat 30 has a composition of raw cotton 60 to 8
The total weight of the thermosetting resin and the thermoplastic resin is appropriately mixed in the range of 40 to 15 parts by weight with respect to 5 parts by weight, and preferably, the resin component 30 is mixed with 70 parts by weight of raw cotton.
Parts by weight are good.

The mixing ratio of the thermosetting resin to the thermoplastic resin in the resin component is appropriately adjusted between 30 to 70 parts by weight of the thermosetting resin and 70 to 30 parts by weight of the thermoplastic resin. May be.

The thermosetting resin may be appropriately selected from a phenol resin, an urea resin, a melamine resin and the like. In this embodiment, a phenol resin is used as the thermosetting resin, and a polyethylene resin is used as the thermoplastic resin. ing.

Here, the function of the thermosetting resin in the mat 30 is mixed to maintain bulkiness, and the function of the thermoplastic resin is used as a binder for bonding fibers.

The resin layer 40 integrated on the front and back surfaces of the mat 30 has a restraining function of restraining the mat 30 by hardening the thermosetting resin and melting and solidifying the thermoplastic resin. I have.

Accordingly, the molded felt 20 shown in FIG.
When the sound absorbing material layer 12 is molded by cold press molding after preheating and softening, the molded felt 20 is restrained by the resin layer 40 even when handled roughly, so that the Even if the thermoplastic resin is melted and the inter-fiber bonding force is weakened, there is an advantage that the molded felt 20 does not break and the handling characteristics are greatly improved.

Further, a resin layer 4 is provided on the front and back sides of the mat 30.
Since 0 is integrated, there is no fluffing or scattering of fibers on the surface, and it is also preferable in the working environment at the time of assembly work,
Also, the fibers on the surface side do not get caught on the harnesses, shafts and the like that are variously installed and penetrated through the insulator dash 10, so that the work of assembling the insulator dash 10 can be performed smoothly, and the mating between the mating component and the fiber can be performed. There is an advantage that defects such as breakage and breakage can be prevented beforehand.

Next, the manufacturing process of the molded felt 20 shown in FIG. 2 will be described with reference to the process chart shown in FIG.
A thermosetting resin, a raw mat forming step of forming a raw mat M by impregnating and mixing a thermoplastic resin, and reacting and curing a part of the thermosetting resin in the mat, and a part of the thermoplastic resin. A heat treatment step of melting, a cooling step of solidifying the molten thermoplastic resin in the mat, and a reheating treatment step of reheating the front and back surfaces of the mat to form the resin layer 40 on the front and back surfaces of the mat. And a cooling step of solidifying the resin layer 40.

Next, based on FIG.
Will be described in detail.

First, in the step of forming the raw material mat M,
For 70 parts by weight of fleece-like raw cotton such as cotton yarn and synthetic fiber,
A powdery material is mixed with 15 parts by weight of the phenol resin and 15 parts by weight of the polyethylene resin, and mixed to form a raw mat M having a thickness of 30 to 40 mm.

Then, the raw material mat M is placed on a conveyor 50.
It is placed on top and supplied to the heating furnace 60.

The heating furnace 60 is provided with a net-type conveyor 61 having a length of 10 to 15 m.
The raw mat M conveyed to the net-type conveyor 61 is blown with hot air in the heating furnace 60 so that a part of the phenol resin is reactively hardened and a part of the polyethylene resin is also melted.

Thereafter, the raw material M is sent to the cooling device 70, and is cooled by the vacuum mechanism 71.
The polyethylene resin in the inside is solidified to form a mat 30 having an appropriate inter-fiber bonding force.

The above is the same as the conventional manufacturing process of the molded felt. The manufacturing process of the molded felt 20 according to the present invention is performed by performing a reheating process and a cooling process.
The point is that a surface treatment is added to the molded felt 20.

That is, after the cooling step, the mat 30 is conveyed by the conveyor 80, and the heating rolls 81, 8
By rolling between the two, the molten component of the polyethylene resin and the cured component of the phenol resin occupy the front and back surfaces of the mat 30 on the surface of the mat 30.

Then, the molding felt 20 is cooled to room temperature by the cooling device 70, the polyethylene resin is solidified, and the molding felt 20 in which the resin layer 40 having the binding action is integrated on the front and back surfaces of the mat 30 is completed. After being cut to a predetermined size by a cutting device, it is used as a molding material.

The heating temperature of the pair of heating rolls 81 and 82 used in the reheating process is adjusted to 130 to 230 ° C., and the distance a between the rolls 81 and 82 is set to the thickness of the mat 30 by b. Where a = b- (1 to 5 m
m).

Therefore, the molded felt 2 according to the present invention
In the manufacture of the production equipment No. 0, a conveyer 80 and heating rolls 81, 8 as a reheating treatment step and a cooling step are added to the existing equipment.
2. It can be easily put into practical use only by providing the cooling device 70.

Next, FIG. 5 shows another embodiment of the formed felt according to the present invention.
A resin layer 40 is formed on one side of the mat 30.

That is, as shown in FIG. 6, only one surface of the mat 30 is reheated and cooled by a single heating roll 81 in the reheating treatment step, so that the resin layer 40 is formed only on one side shown in FIG. A shaped felt 20 'can be formed.

When fabricating the insulator dash 10 using the molded felt 20 'shown in FIG.
As shown in (1), if the resin layer 40 is opposed to the dash panel 13 and the untreated portion is located on the sound insulating material layer 11, the handling characteristics are improved, and the working environment due to scattering of fibers during the assembling work is achieved. Although the function and effect of preventing deterioration of the product are slightly inferior, the function and effect of preventing the workability as well as the catching of the fiber when penetrating many of the penetrating parts into the insulator dash 10 are as follows.
The same thing as the above embodiment can be expected, and compared to the first embodiment,
Since the equipment can be simplified, there is an advantage that it can be manufactured at low cost.

[0052]

As described above, the present invention has the following special functions and effects.

(1) In the molded felt according to the present invention, the thermoplastic resin and the resin layer obtained by curing the thermosetting resin are integrally formed on at least one surface of the mat. Even if the plastic resin is melted and the bonding force between the fibers is reduced, the binding force by the resin layer acts, the molded felt is not easily cut, and the handling characteristics during setting work to the press die are greatly improved. Having.

(2) The molded felt according to the present invention has a resin layer formed on at least one side of the surface of the mat, thereby eliminating fluff on the surface side and suppressing scattering of fibers as much as possible. Sometimes, there is an effect that a good working environment without scattering of fibers can be obtained.

(3) When the molded felt according to the present invention is used for a sound absorbing material layer of an insulator dash, when a penetrating part such as a harness or a shaft is assembled, the fibers on the surface of the molded felt are not caught, so that frays or cuts are generated. This has the effect that the assembling work can proceed smoothly without any occurrence, and the sound absorbing material layer can be prevented from being damaged.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of an automobile insulator dash manufactured using a molded felt according to the present invention.

FIG. 2 is a sectional view showing the configuration of a first embodiment of a molded felt according to the present invention.

FIG. 3 is a process chart in a manufacturing process of the molded felt shown in FIG. 2;

FIG. 4 is a schematic diagram showing a manufacturing process of the molded felt shown in FIG.

FIG. 5 is a sectional view showing a configuration of a molded felt according to a second embodiment of the present invention.

FIG. 6 is an explanatory view of a relevant part showing a step of reheating the formed felt shown in FIG. 5;

FIG. 7 is a sectional view showing an insulator dash for an automobile using the molded felt shown in FIG. 5;

FIG. 8 is a side view showing an installation location of an automobile insulator dash.

FIG. 9 is a sectional view showing a configuration of a conventional insulator dash.

FIG. 10 is a process chart showing a conventional method for producing a molded felt.

FIG. 11 is a schematic view showing a manufacturing process of a conventional molded felt.

FIG. 12 is a sectional view showing a conventional molded felt.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Insulator dash for vehicles 11 Sound insulation material layer 12 Sound absorption material layer 13 Dash panel 20 Molding felt 30 Mat 40 Resin layer 50,80 Conveyor 60 Heating furnace 61 Net type conveyor 70 Cooling device 71 Vacuum mechanism 81,82 Heating roll

Claims (4)

(57) [Claims] 1. A thermosetting resin is cured on at least one surface of a mat (30) in which a thermosetting resin or a thermoplastic resin is mixed as a binder in a fleece-like raw cotton made of cotton yarn, synthetic fiber, or the like, and A molded felt, wherein a resin layer (40) obtained by melting and solidifying a thermoplastic resin is formed. 2. A raw mat (M) is formed by mixing a thermosetting resin and a thermoplastic resin in a fleece-like raw cotton such as cotton yarn or synthetic fiber at an appropriate mixing ratio to form a raw mat (M).
The raw material mat (M) is heated inside to partially cure the internal thermosetting resin, and at the same time, to melt a part of the thermoplastic resin, and through a cooling step, to form the mat (30). A resin layer in which a thermoplastic resin or a thermosetting resin is cured on at least one surface of the mat (30) through a forming process, a reheating treatment on at least one surface of the mat (30), and a cooling process; The process for producing a molded felt according to claim 1, comprising: a surface treatment step of a mat for forming (40). 3. The method for producing a molded felt according to claim 2, wherein the thickness of the mat (30) is 30 mm or more, and the heat treatment step is performed by a net-type conveyor (61). 4. The method according to claim 2, wherein the heat treatment step is performed using an iron plate type conveyor.