Patent Application
20100028591
The disclosure of Japanese Patent Application No. 2008-199596 filed on Aug. 1, 2008 including the specification, drawings and abstract is incorporated herein by reference in its entirety.
1. Field of the Invention
The invention relates to a laminated body for a vehicle, in which a surface material, a cushion material, and a backing cloth are stacked, and a method of producing the same.
2. Description of the Related Art
This kind of laminated body is used exclusively as a vehicle interior material. Therefore, the laminated body needs to meet various flame-retardant regulations. For example, in the Federal Motor Vehicle Safety Standards (FMVSS) 302 that is a typical flame-retardant regulation, when flame of a burner is applied to the laminated body under a certain condition, a burning rate (i.e., a length burned per unit time) needs to be equal to or lower than 100 mm/min.
Japanese Patent No. 3419611 and Japanese Patent Application Publication No. 2001-341220 (JP-A-2001-341220) describe technologies in which the burning rate, at which the laminated body is burned, is controlled while attention is focused on one of burning behaviors of the laminated body (a burning behavior in which only the backing cloth is burned). In the technologies, the burning rate, at which the laminated body is burned, is made equal to or lower than the reference value, by employing a specific material (a specific material of the backing cloth) so that only the backing cloth is stably burned, and the burning rate, at which the backing cloth is burned, is lower than the reference value. For example, in Japanese Patent No. 3419611, the burning rate, at which the laminated body is burned, is made equal to 50 to 60 mm/min, by employing the backing cloth made of cellulosic fibers (mass per square meter of the backing cloth is equal to or larger than 60 g/m2).
In the publication No. 2001-341220, the burning rate, at which the laminated body is burned, is made equal to 70 to 80 mm/min by employing the backing cloth formed by physically interlacing cellulosic short fibers (whose length is equal to or shorter than 100 mm) with each other. In the technology, a plurality of the short fibers are randomly accumulated on a belt conveyer, and then, the short fibers are three-dimensionally interlaced with each other using a water punch (a jet flow of high-pressure water). Thus, it is possible to produce the backing cloth with a relatively high elongation characteristic.
However, in the laminated body in the above-described technology, the burning rate may vary (that is, the burning behavior may be unbalanced) although a definite cause is unknown. Therefore, as shown in
It is considered that the burning behavior is unbalanced because the short fibers of the backing cloth are oriented in parallel with the conveyance direction in which the belt conveyer conveys the short fibers, and therefore, burning in the conveyance direction is promoted. A definite factor that causes the short fibers to be orientated in parallel with the conveyance direction is unknown. However, it is considered that the short fibers are naturally orientated in the conveyance direction, for example, due to an impact of the water punch.
The invention provides a laminated body for a vehicle, which includes a backing cloth that is burned in a lengthwise direction and a width direction in a well-balanced manner so that the laminated body more reliably meets the Federal Motor Vehicle Safety Standards (FMVSS) 302.
A first aspect of the invention relates to a laminated body for a vehicle, which includes a surface material, a cushion material, and a reverse material that are stacked. This kind of laminated body is used exclusively as a vehicle interior material. Therefore, the laminated body is required to meet the Federal Motor Vehicle Safety Standards (FMVSS) 302. In the first aspect, the backing cloth is formed by stacking a plurality of short fibers (typically, cellulosic short fibers) so that the short fibers are oriented in different directions that cross each other, and then, three-dimensionally interlacing the short fibers with each other. Thus, the short fibers are prevented from being oriented in a lengthwise direction or a width direction, or the possibility that the short fibers are oriented in the lengthwise direction or the width direction is reduced by stacking the short fibers so that the short fibers are (actively) oriented in the different directions that cross each other. Accordingly, the backing cloth is burned in the lengthwise direction and the width direction in a well-balance manner.
A second aspect of the invention relates to a method of producing the laminated body for a vehicle. The method includes four processes (i.e., a fiber orientation process, a stacking process, an interlacing process, and a joining process). That is, in the fiber orientation process, a first belt-shaped web which includes a plurality of short fibers that are carded (i.e., the first belt-shaped web in which the short fibers are oriented in substantially parallel with the lengthwise direction of the web) is folded in a zigzag manner on the belt conveyer As a result, the short fibers are oriented in different directions that cross each other, and cross a conveyance direction in which a belt conveyer conveys the first belt-shaped web. Then, in the stacking process, a second belt-shaped web, which includes a plurality of short fibers that are carded, is folded in the zigzag manner on the belt conveyer so that the short fibers are oriented in different directions that cross each other, and cross the conveyance direction, thereby forming a laminated web in which the first belt-shaped web and the second belt-shaped web are stacked. Thus, it is possible to relatively easily form the laminated web in which the short fibers of the first and second belt-shaped webs are oriented in different directions that cross each other, and cross the conveyance direction. Then, in the interlacing process, the short fibers of the laminated web are three-dimensionally interlaced with each other physically or mechanically (in a manner such that deterioration of the elongation characteristic of the laminated web is minimized), thereby forming the backing cloth. In the joining process, the surface material, the cushion material, and the backing cloth are arranged in the stated order, and then, the surface material, the cushion material, and the backing cloth are joined.
A third aspect of the invention relates to a method of producing a laminated body for a vehicle. The method includes three processes (i.e., a fiber orientation process, an interlacing process, and a joining process). In the fiber orientation process, a first belt-shaped web, which includes a plurality of short fibers that are carded, is folded in a zigzag manner on a belt conveyer so that an even number of layers are formed, and the short fibers are oriented in different directions that cross each other, and cross a conveyance direction in which the belt conveyer conveys the first belt-shaped web. In the interlacing process, the short fibers in all the layers of the first belt-shaped web are three-dimensionally interlaced with each other physically or mechanically, thereby forming the backing cloth (without performing the above-described stacking process). Then, in the joining process, the surface material, the cushion material, and the backing cloth are arranged in the stated order, and the surface material, the cushion material, and the backing cloth are joined, thereby forming the laminated body.
In the laminated body according to the first aspect of the invention, the backing cloth is burned in the lengthwise direction and the width direction in a well-balanced manner, to reliably meet the Federal Motor Vehicle Safety Standards (FMVSS) 302. According to the second aspect of the invention, the laminated body is relatively easily produced. According to the third aspect of the invention, the laminated body is further easily produced.
The features, advantages, and technical and industrial significance of this invention will be described in the following detailed description of example embodiments of the invention with reference to the accompanying drawings, in which like numerals denote like elements, and wherein:
Hereinafter, embodiments of the invention will be described with reference to
A method of producing the laminated body 2 according to the first embodiment includes four processes (i.e., a fiber orientation process, a stacking process, an interlacing process, and a joining process) (refer to
As shown in
Then, as shown in
A typical short fiber is a fiber (a natural fiber or a synthetic fiber) with a length of 100 mm or shorter, preferably a length of 30 mm to 70 mm, and more preferably a length of 38 mm to 64 mm. In the embodiment, cellulosic short fibers (for example, viscose rayon fibers, cupra rayon fibers, or plant fibers such as cotton fibers) are used. The cellulosic short fibers are generally burned stably. Also, the cellulosic short fibers are burned while being carbonized. Therefore, the cellulosic short fibers suppress the burning of the surface material 4 and the cushion material 6 as described later (that is, the cellulosic short fibers have an effect of suppressing the burning (hereinafter, referred to as “a burning suppression effect”)). In the embodiment, short fibers consisting of synthetic fibers (for example, polyethylene terephthalate fibers, acrylic fibers, polyamide fibers, or acetate fibers) may be blended with the cellulosic short fibers. The polyethylene terephthalate (PET) fibers are durable and flame-retardant, as compared to the other synthetic fibers. Therefore, the polyethylene terephthalate (PET) fibers may be appropriately used. The typical blending ratio by weight between the cellulosic short fibers and the synthetic fibers is 50:50 to 80:20, and preferably 55:45 to 75:25, when the entire weight is 100. When the blending ratio is set to a value in the above-described range, it is possible to appropriately obtain the burning suppression effect of the backing cloth 8, which is derived from the cellulosic short fibers.
In the stacking process, a second belt-shaped web 12 is folded in the zigzag manner on the first belt conveyer 38a so that fibers of the second belt-shaped web 12 are oriented in different directions that cross each other. Thus, a laminated web 14 (described later) is formed. The second belt-shaped web 12 (with a width W1) includes a plurality of short fibers that are carded. The short fibers are oriented in substantially parallel with the lengthwise direction of the second belt-shaped web 12. As shown in
While the second belt-shaped web 12 is folded at a folding angle θ2 (that is equal to the folding angle θ1 in the embodiment) in the zigzag manner on the first belt conveyer 38a by reciprocating the cross lapper 36 (in synchronization with the supply of the first belt-shaped web 10), the fibers are oriented in different directions that cross each other, and cross the conveyance direction F. Thus, the laminated web 14, in which the first belt-shaped web 10 and the second belt-shaped web 12 are stacked, is formed (refer to
In the interlacing process, as shown in
Then, in the joining process, as shown in
The cushion material 6 needs to have a cushion property to ensure that an occupant is seated comfortably. For example, the cushion material 6 consists of a polyurethane foam, a polyethylene foam, or a polyester foam. It is preferable to employ the polyurethane foam (density: 10 kg/m3 to 30 kg/m3) with high sag resistance, as the cushion material 6. Flame-retardant treatment may be separately performed on the polyurethane foam. However, for example, in terms of cost, it is preferable not to perform the flame-retardant treatment on the polyurethane foam.
As described above, the backing cloth 8 is formed by stacking a plurality of cellulosic short fibers so that the fibers are oriented in different directions that cross each other, and three-dimensionally interlacing the short fibers with each other. Thus, in the backing cloth 8, the short fibers are actively oriented in different directions that cross each other. Therefore, it is possible to avoid the situation where the short fibers are oriented in the lengthwise direction or the width direction, or to reduce the possibility the short fibers are oriented in the lengthwise direction or the width direction. As a result, the backing cloth 8 is burned in the lengthwise direction and the width direction in a well-balanced manner, that is, the backing cloth 8 is burned in the lengthwise direction at the substantially same burning rate as the burning rate at which the backing cloth 8 is burned in the width direction. Also, although the short fibers are interlaced with each other in the backing cloth 8 in the embodiment, movement of the short fibers is not restrained. Therefore, the backing cloth 8 is flexible and lightweight, and has an appropriate elongation characteristic. Also, the backing cloth 8 in the embodiment has a flame-retardant effect, because the cellulosic short fibers are oriented in the above-described manner. Therefore, it is not necessary to separately add a flame-retardant agent to the backing cloth 8. An ordinary flame-retardant agent (for example, a chlorinated organic phosphorous compound) induces a phenomenon in which windows of a vehicle are fogged up (i.e., a so-called fogging phenomenon). Therefore, it is preferable not to use the flame-retardant agent for the backing cloth 8.
The mass per square meter of the backing cloth 8 is 20 g/m2 to 60 g/m2, and preferably 30 g/m2 to 60 g/m2. If the mass per square meter of the backing cloth 8 is less than 20 g/m2, the backing cloth 8 is unlikely to produce the effect of suppressing the burning of the other materials (the surface material 4 and the cushion material 6). The mass per square meter of the backing cloth 8 may be larger than 60 g/m2. However, if the mass per square meter of the backing cloth 8 is larger than 60 g/m2, the cost is increased, and the weight of the laminated body 2 is excessively increased. Also, when the mass per square meter of the backing cloth 8 is set to a value in a range of 40 g/m2 to 60 g/m2, the backing cloth 8 is stably burned.
The laminated body 2 for a vehicle, which is produced by the above-described production method, includes the backing cloth 8 in which the plurality of short fibers are actively oriented in the different directions that cross each other (i.e., the cross-layered backing cloth 8). Because the backing cloth 8 is burned in the lengthwise direction and the width direction in a well-balanced manner, the laminated body 2 reliably meets the Federal Motor Vehicle Safety Standards (refer to Table 2). Also, in the embodiment, because the short fibers of the backing cloth 8 are physically interlaced with each other, the laminated body 2 has an appropriate elongation characteristic, and is appropriately used as the vehicle interior material. Particularly because the short fibers of the backing cloth 8 are stacked so that the short fibers are oriented in the different directions that cross each other, the elongation characteristic of the laminated body 2 in the lengthwise direction is balanced with the elongation characteristic of the laminated body 2 in the width direction, that is, the elongation characteristic of the laminated body 2 in the lengthwise direction is substantially the same as the elongation characteristic of the laminated body 2 in the width direction. Thus, the laminated body 2 is appropriately used as a cover material that covers a three-dimensional structural body such as a vehicle seat (refer to Table 2).
Hereinafter, a method of producing a laminated body according to a second embodiment will be described. The basic configuration of the laminated body in the second embodiment is substantially the same as that in the first embodiment. Therefore, for example, the same structures as those in the first embodiment are denoted by the same reference numerals, and the detailed description thereof will be omitted. The method of producing the laminated body according to the second embodiment includes the following three processes (a fiber orientation process, an interlacing process, and a joining process). In the fiber orientation process in the second embodiment, as shown in
Then, in the interlacing process, the short fibers in all the layers of the first belt-shaped web 10 are three-dimensionally interlaced with each other physically or mechanically. In the joining process, the outer surface member 4, the cushion member 6, and the backing cloth 8 are arranged in the stated order, and then, the outer surface member 4, the cushion member 6, and the backing cloth 8 are joined. Thus, the laminated body is formed. According to the second embodiment, it is possible to produce the laminated body by a relatively simple method in which the above-described stacking process is omitted, using a relatively simple configuration (in which the second belt-shaped web 12 and the third belt conveyer 33 are omitted).
Hereinafter, the advantageous effects obtained in the embodiments of the invention will be described based on examples of experiments. In the experiments, the backing cloth 8 in a first example and a backing cloth 9 in a first comparative example were used (refer to
The laminated body 2 in the first example was produced by arranging the surface material 4, the cushion material 6, and the backing cloth 8 in the stated order, and joining the surface material 4, the cushion material 6, and the backing cloth 8 (refer to
A laminated body 20 in the first comparative example was produced by arranging the surface material 4, the cushion material 6, and the backing cloth 9 in the stated order (refer to
A sample Sh1 (length 350 mm×width 100 mm), and a sample Sw1 (length: 100 mm×width: 350 mm) were extracted from the laminated body 2 in the first example (refer to
Similarly, a sample Sh2 and a sample Sw2 were extracted from the laminated body 20 in the first comparative example (refer to
Table 2 shows results of measurements in each experiment.
In the laminated body 2 in the first example, a difference between the highest burning rate of the sample Sh1 and the highest burning rate of the sample Sw1 was extremely small. Thus, the burning rate of each sample (30 mm/min to 40 mm/min) met the Federal Motor Vehicle Safety Standards (FMVSS) 302. The result of the experiment shows that the backing cloth 8 of the laminated body 2 in the first example is burned in the lengthwise direction and the width direction in a well-balance manner, that is, the backing cloth 8 is burned in the lengthwise direction at the substantially same burning rate as the burning rate at which the backing cloth 8 is burned in the width direction. Thus, the result of the experiment shows that the laminated body 2 in the first example more reliably meets the Federal Motor Vehicle Safety Standards.
In contrast, in the laminated body 20 in the first comparative example, a difference between the highest burning rate of the sample Sh2 and the highest burning rate of the sample Sw2 was extremely large (that is, the laminated body 20 was burned in the lengthwise direction and the width direction in an unbalanced manner). Particularly, the highest burning rate of the sample Sh2 was equal to an upper limit value (100 mm/min) in the Federal Motor Vehicle Safety Standards. It is considered that the laminated body 20 in the first comparative example was burned in the lengthwise direction and the width direction at different burning rates because the short fibers of the backing cloth 9 were orientated in the conveyance direction F, and therefore, burning in the conveyance direction F was promoted. This result strongly suggests that the laminated body 20 (the backing cloth 9) in the first comparative example may not meet the Federal Motor Vehicle Safety Standards, depending on the combination of the backing cloth 9 and the other portions (i.e., the surface material 4 and the cushion material 6).
In the laminated body 2 in the first example, a difference between the fracture elongation of the backing cloth 8 of the sample Sh1 and the fracture elongation of the backing cloth 8 of the sample Sw1 was small. The fracture elongation of the backing cloth 8 of each of the sample Sh1 and the sample Sw1 was an appropriate value (50% to 70%). Similarly, a difference between the tensile strength of the backing cloth 8 of the sample Sh1 and the tensile strength of the backing cloth 8 of the sample Sw1 was small. The tensile strength of the backing cloth 8 of each of the sample Sh1 and Sw1 is an appropriate value (approximately 40 N/25 mm). The results show that in the laminated body 2 (the backing cloth 8) in the first example, the elongation characteristic in the lengthwise direction is substantially the same as the elongation characteristic in the width direction. Thus, the results show that the laminated body 2 in the first example has an appropriate elongation characteristic, and therefore, the laminated body 2 can be appropriately used as the vehicle interior material.
That is, in the laminated body 2 in the first example, the fracture elongation of the backing cloth 8 is relatively high, and thus, the backing cloth 8 is easy to elongate. Therefore, for example, when the laminated body 2 is used as a cover material that covers a vehicle seat, it is possible to appropriately elongate the laminated body 2 in accordance with the outer shape of the seat while preventing as much as possible creases in the laminated body 2 or twisting of the laminated body 2 (that is, the finished vehicle seat has good appearance, and an occupant is comfortably seated on the finished vehicle seat). In addition, in the laminated body 2, the tensile strength of the backing cloth 8 is moderately low, and therefore, the backing cloth 8 can be stably stretched. For example, if the cover material (the laminated body 2) can be stably stretched when a sewing operation is performed in a process of producing the cover material, the sewing operation is easily performed, and a good sewing line is formed (that is, the finished cover material has good appearance). Thus, it has been found that the laminated body 2 (the backing cloth 8) can be appropriately used, for example, as the cover material that covers the three-dimensional structural body such as the vehicle seat.
In contrast, in the laminated body 20 in the first comparative example, a difference between the fracture elongation of the backing cloth 9 of the sample Sh2 and the fracture elongation of the backing cloth 9 of the sample Sw2 was extremely large. Similarly, a difference between the tensile strength of the backing cloth 9 of the sample Sh2 and the tensile strength of the backing cloth 9 of the sample Sw2 was extremely large. Particularly, the fracture elongation of the backing cloth 9 of the sample Sh2 was 35.01% that was an extremely low value (that is, the backing cloth 9 of the sample Sh2 was difficult to elongate). Further, the tensile strength of the backing cloth 9 of the sample Sh2 was 65.9 N/25 mm that was an extremely high value (that is, the backing cloth 9 of the sample Sh2 was difficult to stretch). Accordingly, it has been found that the laminated body 20 (the backing cloth 9) is slightly inappropriate for use as the vehicle interior material. Thus, if the laminated body 20 (the backing cloth 9) in the first comparative example is used as the vehicle interior material (particularly as the cover material), properties of the finished vehicle interior material may be adversely affected.
The laminated body for a vehicle and the method of producing the same according to the invention are not limited to the above-described embodiments. The invention may be realized in other embodiments. (1) In the fiber orientation process in the embodiments, the raw fibers (the short fibers) are disentangled using the fiber-spreading device 30, and the spread short fibers are supplied onto the belt conveyer. That is, a dry method (that makes it possible to more reliably orient the short fibers) is employed. However, a wet method, in which the raw fibers (the short fibers) are dispersed in a solution, and then, a sheet of the fibers is formed using a paper machine, may be employed as long as the wet method makes it possible to orient the short fibers.
(2) In the stacking process in the first embodiment, the first belt-shaped web 10 and the second belt-shaped web 12 are placed in the same cross lapper 36 (i.e., the rationally-designed configuration, in which the both webs are supplied in synchronization with each other, is employed). However, the arrangement of the both webs is not limited. For example, the first belt-shaped web 10 and the second belt-shaped web 12 may be placed in respective separate cross lappers. In this case, the first belt-shaped web 10 may be placed on one side of the first belt conveyer 38 and the second belt-shaped web 12 may be placed on the other side of the first belt conveyer so that the first belt-shaped web 10 and the second belt-shaped web 12 face each other. Also, in the first embodiment, the first belt conveyer 38 includes the two conveyers, that is, the first belt conveyer 38a used to convey the web, and the first belt conveyer 38b (the mesh belt conveyer) used to interlace the fibers of the web. However, the entire first belt conveyer 38 may be one mesh belt conveyer.
(3) In the first embodiment, the folding angle θ1 at which the first belt-shaped web 10 is folded and the folding angle θ2 at which the second belt-shaped web 12 is folded may be set separately from each other, and may be set to values larger than 0 degree and smaller than 45 degrees, as long as the short fibers in each belt-shaped web are oriented in different directions that cross each other. The folding angle θ1 and the folding angle θ2 may be the same, or may be different from each other. In the first embodiment, the size (W1 and W2) of the first belt-shaped web 10 is the same as the size (W1 and W2) of the second belt-shaped web 12. However, the size of the first belt-shaped web 10 may be different from the size of the second belt-shaped web 12.
(4) In the interlacing process in the embodiments, the fibers of the laminated web 14 are interlaced with each other physically or mechanically (i.e., the configuration, which produces the backing cloth 8 with an appropriate elongation characteristic, is employed). However, the use of an adhesive agent or binder fibers need not necessarily be prohibited. That is, a certain amount of the adhesive agent or the like may be added to the backing cloth 8, as long as the certain amount of the adhesive agent or the like does not adversely affect the flame retardancy or the elongation characteristic of the backing cloth 8. (5) In the embodiments, the laminated body 2 includes only the surface material 4, the cushion material 6, and the backing cloth 8. However, because the surface material 4, the cushion material 6, and the backing cloth 8 are main portions of the laminated body 2, the laminated body 2 may further include one or more elements (for example, a resin plate and/or a coating layer), in addition to the surface material 4, the cushion material 6, and the backing cloth 8.
(6) In the embodiments, the backing cloth 8 includes solely the cellulosic fibers. The backing cloth 8 in the embodiments has the flame-retardant effect, because the short fibers are oriented in different directions that cross each other as described above. Therefore, in addition to, or instead of the cellulosic short fibers, short fibers other than the cellulosic short fibers may be used. Examples of the short fibers other than the cellulosic short fibers include polyester short fibers, polyamide short fibers, polyacrylonitrile short fibers, polyolefin short fibers, protein short fibers such as polylactate short fibers, and polyfluoroethylene short fibers such as polytetrafluoroethylene (PTFE) short fibers. It is preferable that the short fibers be stacked so that the short fibers in adjacent layers are oriented in different directions that cross each other in the entire backing cloth. However, the backing cloth may include a portion in which the short fibers in adjacent layers are not oriented in different directions that cross each other, as long as the elongation characteristic of the backing cloth is not adversely affected.
(7) In each of the embodiments, the laminated web 14 is formed using only the first belt-shaped web 10, or the first belt-shaped web 10 and the second belt-shaped web 12. However, another belt-shaped web, which is long in the conveyance direction F in which the first belt conveyer 38 conveys the web, may be disposed on at least one of an upper portion and a lower portion of the laminated web 14 (an example of a crisscross method). The other web is formed so that the short fibers are oriented in substantially parallel with the lengthwise direction thereof (i.e., the conveyance direction F). In this case, it is possible to more reliably stack the short fibers of the backing cloth 8 so that the short fibers in adjacent layers are oriented in different directions that cross each other. Also, the other belt-shaped web may be inserted between the first belt-shaped web 10 and the second belt-shaped web 12. (8) In the second embodiment, the other belt-shaped web may be disposed on at least one of the upper portion and the lower portion of the first belt-shaped web 10 (another example of the crisscross method). In this case, it is possible to stack the short fibers of the belt-shaped webs so that the short fibers in adjacent layers are oriented in different directions that cross each other, while the second belt-shaped web 12 (the third belt conveyer 33) is omitted. An operation for disposing the other belt-shaped web on the first belt-shaped web 10, or an operation for inserting the other belt-shaped web between the first belt-shaped web 10 and the second belt-shaped web 12 may be performed in the fiber orientation process or the stacking process before the interlacing process, or before or after the fiber orientation process or the stacking process.
(9) In the embodiments, each of the first belt-shaped web 10 and the second belt-shaped web 12 is folded so that a predetermined number of layers are formed. Each of the first belt-shaped web 10 and the second belt-shaped web 12 may be folded so that 2n layers (n is a positive integer) are formed, for example, by adjusting the speed at which the cross lapper 36 is reciprocated, with respect to the speed at which the first belt conveyer 38a conveys the web. Typically, the first belt-shaped web 10 (the second belt-shaped web 12) is folded so that two to approximately twelve layers are formed, and the mass per square meter is equal to a desired value. The number of the layers of the first belt-shaped web 10 and the number of the layers of the second belt-shaped web 12 may be the same or different from each other.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2008-199596 | Aug 2008 | JP | national |
