JP3239584B2 - Automotive interior materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to automotive interior materials such as floor mats and trunk mats having excellent sound and vibration proof properties.

[0002]

2. Description of the Related Art Conventionally, as interior materials used for floor mats or trunk mats of automobiles, those generally constituted by a skin material 10, an adhesive 20, and a sound absorbing material 30 as shown in FIG. It is a target. That is, a skin material 10 made of a nonwoven fabric, a carpet, or the like, and a sound absorbing material 30 made of felt, foamed polyurethane, or the like are integrated via an adhesive 20 such as an acrylic, phenol, or hot melt type. It is. Alternatively, many use only flat felts.

[0003]

In the conventional interior materials as described above, first, since the skin material and the sound absorbing material are integrated using an adhesive, the cost of the adhesive is reduced. In addition, there is a problem that it takes much time and labor for attaching.

[0004] Next, for example, a floor mat or the like which uses a flat felt or a flat material in which the above-mentioned skin material and a sound absorbing material are integrated with an adhesive on a body panel having unevenness is used. When it cannot be sufficiently adhered to the surface of the panel, voids are generated and the soundproofing performance becomes insufficient, and it is difficult to maintain smoothness due to the voids. was there.

In recent years, a molded article of urethane foam or a compression molded article of felt, which conforms to the uneven shape of a vehicle body panel, has been increasingly used instead of a flat one. In the case of the molded product, since a film is formed on the surface or the film remains in the internal fine structure, the internal air does not easily flow, and the foamed surface becomes hard and the soundproofing effect may be insufficient. . On the other hand, in the case of the felt compression-molded article, since a flat felt is compression-molded, there is a problem that a portion to be highly compressed is generated and becomes locally too hard, so that the soundproof performance is reduced.

For example, in the case of an interior material such as a trunk mat, the object is naturally placed on the trunk mat because the interior of the trunk of the automobile is a space for temporarily storing the object. There are many types of passenger car type trunks in which a spare tire is usually stored under the trunk mat. In this case, the sound absorbing material of the trunk mat is
Conventionally, since it is made of a soft material such as felt or urethane foam, it is difficult to maintain smoothness. Therefore, as shown in FIG. 3 (b), usually, a reinforcing material trunk board 7 is set. Extra materials and man-hours were required, such as placing a trunk mat.

[0007] The present invention has been made in view of such prior art, and in particular, in order to realize a quiet cabin space, has better sound absorption, has a desired density, and An automotive interior that can be molded into a shape that closely adheres to the uneven shape of the surface to be used, such as body panels, has high dimensional accuracy, has sufficient smoothness, and has improved appearance problems such as surface waving Provide materials.

[0008]

In order to solve the above problems, the present invention employs the following technical means.

According to a first aspect of the present invention, a non-woven fabric and a fiber assembly made of short fibers having a fiber diameter distribution center of 30 denier or less are integrated by heating and melting. It is molded to an average apparent density of 0.04 to 0.3 g / cm ³ according to the shape of the body panel,
The nonwoven fabric is set on the inner wall of the mold in advance, molded by a filling method in which the short fibers are blown together with air, and by controlling the ventilation of the mold, a density distribution of at least 0.01 g / cm ³ or more is obtained in the fiber aggregate. An interior material for automobiles characterized by being provided with a material having a desired density with excellent sound absorption properties, and easily formed into a shape which is in close contact with the uneven shape of the surface used such as a vehicle body panel. For vehicles that have high dimensional accuracy and high soundproofing performance, can stably and uniformly control the density of fiber aggregates, and can sufficiently withstand use where rigidity is required. It provides interior materials.

According to a second aspect of the present invention, the interior of the automobile according to the first aspect is characterized in that both the nonwoven fabric and the fiber assembly are made of a material containing at least 10% by weight or more of a binder of a low melting point short fiber. It is a material which provides an automobile interior material which can be easily integrated by heating and melting.

[0011]

[0012]

According to a third aspect of the present invention, in addition to any one of the first and second aspects, when the fiber aggregate is molded, welded, and solidified simultaneously with the nonwoven fabric, hot air is injected into the mold. Or, by providing a feature of being formed by injecting steam, it is possible to improve the sound absorbing property, the uniformity of the density distribution and the molding cycle, and to provide an interior material for automobiles capable of making the curing more uniform. is there.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below. First, in the invention of claim 1, the nonwoven fabric to be used is not particularly limited in its material. On the other hand, as a fiber aggregate to be used, a thin short fiber having a fiber diameter distribution center of 30 denier or less is used. In addition to the use, the apparent density was kept within a predetermined range, so that the airflow resistance inside the fiber assembly was increased, and the sound absorption characteristics were improved. If a fiber having a fiber diameter distribution center of 30 denier or more is used, the fiber becomes coarse at the same apparent density, the airflow resistance is not increased, and the sound absorption characteristics are poor.
If the apparent density is increased to improve the sound absorbing property, the sound-absorbing performance is lowered because it is too hard. Further, increasing the apparent density leads to an increase in weight, which is not preferable for weight reduction. From these viewpoints, in order to achieve the object of the present invention, the upper limit of the apparent density is 0.3 g / c.
it is necessary to set the m ^3. Further, even when a fine fiber of 30 denier or less is used, the apparent density is 0.04 g / cm ^3.
Below, ventilation resistance does not become large and sound absorption property cannot be expected.

The short fibers used as the material of the fiber assembly according to the present invention basically have a fiber distribution center of 30 denier or less, and 15 denier or less in order to realize high sound absorption performance. It is desirable to use short fibers. As a material of the short fiber as the material, for example, natural fibers such as wool, cotton, and hemp can be used in addition to synthetic fibers such as polyester, polypropylene, polystyrene, nylon, and vinylon. Furthermore, short fibers opened from a cloth using these fibers can also be used.

Further, the fiber aggregate according to the present invention can be obtained by various molding methods. However, in order to achieve more uniform filling and to reduce the density distribution, the fiber aggregate may be formed as described in claim 3. A method is used in which fine fibers are blown apart into the mold together with gas (air), and only this air is discharged from many pores, and only short fibers are filled into the mold and molded. Is preferred. By such an air-conveying filling method, it is possible to fill a shape along a mold conforming to an uneven panel shape, and to obtain a uniform and flexible porous material as a whole.

The nonwoven fabric and the fiber assembly constituting the present invention require a binder. Examples of the binder include a phenol resin which is melted and solidified by heating, a urethane adhesive which is solidified by steam blowing, and a thermoplastic resin which is melted at a lower temperature than the base short fiber. There is something. However, in the case of powder, the binder in the powder is biased at the time of blow-filling, causing poor dispersion.In addition, the binder may be clogged in the air vent holes to cause poor filling or poor density, or only the binder may be scattered. On the other hand, when the binder is in a liquid state, the fibers are agglomerated at the time of mixing, and good blow-filling cannot be obtained.

On the other hand, when a binder of low melting point short fibers is used, good dispersion can be obtained by mixing using a fiber opening machine or the like. When filling short fibers as a material, no trouble occurs. As such a fibrous binder, a polyester resin having a low melting point which is melted by heating or steam, or a fiber having a melting point lower than that of a short fiber serving as a base material such as polyethylene or polypropylene can be used. Desirably, the fiber material is composed of a low melting point component and a high melting point component, and a composite fiber in which the low melting point component is arranged outside the high melting point component, that is, on the fiber surface, is advantageous in terms of durability and acoustic performance. It is.

That is, if the conjugate fiber is heated and molded at a temperature higher than the melting point of the low melting point component and lower than the melting point of the high melting point component, the binder fiber can be bound in the perfect fiber state by the melting point of the low melting point component, High durability and acoustic characteristics can be secured.

As a method of forming the porous layer of the fiber aggregate in which the fiber-based binder is mixed as described above, hot pressing or heating molding can be considered. In such a forming method, the porous layer is formed. Since it has an insulating effect, it requires long-time heating to melt the internal binder, and it is difficult to shorten the molding cycle. If the molding temperature is set high, the molding cycle can be shortened. However, a binder other than the reaction-curable type, for example, a thermoplastic binder such as polyethylene fiber, may lose its shape during mold release.

Therefore, as a molding method, the temperature of the mold is adjusted to be lower than the melting point of the binder, and the binder is melted by blowing hot air or steam having a temperature higher than the melting point to form the fiber assembly. A method of forming and simultaneously firmly integrating with the nonwoven fabric is desirable. In this case, if a means for switching between hot air and cold air is added, the molding cycle can be further improved, and uniform melting and solidification can be achieved even inside the porous material by blowing hot air or the like.

As described above, a short fiber as a material is blown into a mold together with a fibrous binder to melt the binder, to bind the short fibers and to integrate them with the non-woven fabric, thereby providing a soft and flexible material. It is possible to obtain an automotive interior material that is lightweight and has a shape that matches the shape of the surface to be used, such as a body panel. By using such a porous formed body of fiber aggregates, it is not necessary to apply or bond an adhesive and to carry out processes such as drying, and to obtain an automotive interior material having high dimensional accuracy and excellent soundproofing performance. Can be.

Example 1: Floor mat (see FIG. 1) FIG. 1 (a) is a schematic longitudinal sectional view of an apparatus for manufacturing an automobile interior material according to the present invention, and FIG. 1 (b) and (c). 1 is an example of a schematic view of a plan view and a sectional view of a floor-mat product manufactured by the manufacturing apparatus. Referring to FIG. 1, an interior material for a vehicle (floor-mat) according to the present invention will be described below.
The manufacturing method of the method will be specifically described. First, a mold (molding die) conforming to the shape of the floor mat was manufactured and arranged as shown in FIG.

In FIG. 1 (a), 1 is a press molding machine, 2A and 2B are upper and lower molds mounted on the press molding machine 1, and 3 is a mold into the molds 2A and 2B. A short fiber blowing port 4 is a hot air and a cold air feeding or discharging port.

Using the above-described manufacturing apparatus, first, a polyester nonwoven fabric (320 g / m ² ) 5 obtained by mixing black and white fibers and needle punching is set in the upper mold 2A, and the upper mold is lowered to form the upper mold. A polyester short fiber (6 denier × 51 m / m length) and a polyester fiber having a double cross section (outer melting point: 95 ° C., inner (core) side melting point: 23)
A mixture obtained by mixing and dispersing 5 ° C. in a ratio of 7: 3 was blown and filled together with air from the blowing opening 3. After filling, the upper mold was lowered to the product thickness, hot air at 150 ° C. was sent from 4 for 30 seconds, and air at room temperature was further sent for 30 seconds to perform molding.
The physical properties of the integrated product of the obtained fiber assembly molded article and the nonwoven fabric were as follows. Adhesive strength between fiber and non-woven fabric: 0.56 kg / cm width Density: 0.05 g / cm ^{3 When} this product was laid on a floor mat of an automobile, no gap was formed on the surface of the uneven body panel A satisfactory floor mat having good smoothness and cushioning property without any surface waving was obtained.

Example 2: Trunk mat (see FIGS. 2 and 3) A polyester nonwoven fabric prepared by mixing black and white fibers and needle punching using the manufacturing apparatus shown in Example 1 and in the same manner as in Example 1. 320 g / m ² ) 5 was set in the upper mold, and the upper mold was lowered to place a polyester short fiber (6 denier × 51 m / m length) between the upper mold and the lower mold in a double structure. Polyester fiber (95 ° C. outer melting point, 235 ° C. inner (core) side melting point, mixed and dispersed in a ratio of 7: 3) was blown and filled together with air from the blowing port 3.
The air permeability of the mold of the portion A in the plan view of the trunk mat product shown in FIG. 2 (a) was increased and the blowing air volume was changed. After filling, lower the upper die to the product thickness,
Hot air at 50 ° C. was fed for 30 seconds, and air at room temperature was further fed for 30 seconds to perform molding. The physical properties of the integrated product of the obtained fiber assembly molded article and the nonwoven fabric were as follows. Adhesive strength between fiber and non-woven fabric: 0.56 kg / cm width Central density (100 × 100 mm from 400 mm width center)
² cut): 0.08g / cm ³ near Density: 0.05 g / cm ³ this article a good smoothness was laid on trunk mats car trunk mat appearance satisfactory cushioning and was obtained . This mat also has a stiffness at the central portion, so that the reinforcing trunk board 7 as shown in FIG. 3 (b) is not required, and the mat as shown in FIG. 3 (a) is satisfactory. Was done.

[0027]

As is apparent from the above description, the invention of claim 1 is characterized in that a non-woven fabric and a fiber aggregate made of short fibers having a fiber diameter distribution center of 30 denier or less are melted and integrated. The fiber aggregate has an average apparent density of 0.04 to 0.3 g according to the shape of the vehicle body panel.
/ Cm ³ , the non-woven fabric is set on the inner wall of the mold in advance, and is molded by a filling method in which the short fibers are blown with air. By adjusting the ventilation of the mold, at least 0 .
An automotive interior material characterized in that it has a density distribution of 01 g / cm ³ or more.
It has a desired density with excellent sound absorption properties and can be easily formed into a shape that is in close contact with the irregularities on the surface used for the body panel, etc., and has high shape and dimensional accuracy and excellent soundproofing performance. There is provided an automotive interior material capable of stably and uniformly controlling the density and sufficiently withstanding use in a portion requiring rigidity.

The invention according to claim 2 is characterized in that the nonwoven fabric and the fiber assembly are both made of a material containing at least 10% by weight or more of a binder of low melting point short fibers. Thus, there is provided an automobile interior material capable of easily integrating the both by heating and melting.

[0029]

[0030]

According to a third aspect of the present invention, in addition to any one of the first and second aspects, when the fiber aggregate is molded, welded and solidified, and simultaneously integrated with the nonwoven fabric,
The interior material for automobiles, which is characterized by being made of hot air or steam blown into the mold to improve sound absorption, uniformity of density distribution and molding cycle, and to make curing more uniform. Is obtained.

[Brief description of the drawings]

FIG. 1A is a schematic cross-sectional view of an apparatus for molding an interior material (floor-mat) for an automobile according to the present invention, and FIGS. 1B and 1C are obtained by this apparatus. It is an example which shows the outline of the top view and sectional drawing of the obtained floor-mat product.

FIGS. 2 (a) and 2 (b) are automobile interior materials (trunk mats) obtained using the molding apparatus of FIG. 1 (a).
It is the schematic of the figure which shows the plane and cross section of a product.

FIG. 3 is an example of a comparative sectional view of the structure of the trunk mat of the present invention (a) and the conventional trunk mat (b).

FIG. 4 is a schematic configuration diagram of a conventional automobile interior material.

[Explanation of symbols]

 1: Press molding machine 2A: Mold (upper mold) 2B: Mold (lower mold) 3: Short fiber blowing port 4: Hot and cold air inlet / outlet 5: Nonwoven fabric 6: Fiber aggregate (formed) body 7: Trunk board (reinforcing material) 8: Spare tire 10: Skin material 20: Adhesive 30: Sound absorbing material

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60R 13/01 B29C 41/08 B29C 70/30

Claims (3)

(57) [Claims] 1. A non-woven fabric and a fiber aggregate made of short fibers having a fiber diameter distribution center of 30 denier or less are heat-melted and integrated, and the fiber aggregate has a shape of a vehicle body panel. Average apparent density 0.04 ~ 0.3
g / cm ³ , the nonwoven fabric is set on the inner wall of the mold in advance, and the short fibers are molded by a filling method in which the fibers are blown together with air. An automobile interior material having a density distribution of 0.01 g / cm ³ or more. 2. The automotive interior material according to claim 1, wherein both the nonwoven fabric and the fiber aggregate are made of a material containing at least 10% by weight or more of a low-melting short fiber binder. 3. The method according to claim 1, wherein when the fiber aggregate is formed and solidified and simultaneously integrated with the nonwoven fabric, hot air or steam is blown into the mold.
Automotive interior materials as described.