JPH0243613B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a trim cover and a trim cover fused by ultrasonic fusion.

BACKGROUND OF THE INVENTION Conventional techniques for trim covers used for surface materials such as seats will be explained with reference to FIGS. 1 to 5.

In the figure, numeral 1 is a skin material, 2 is a wading made of ordinary urethane made by relatively thinly slicing a cushion material such as urethane foam, and 2a is a skin material 1.
and wading 2, and 3 indicates the back base fabric.

Figure 1 shows the outer skin material 1, wading 2, and back base fabric 3.
A cross section of a seat trim cover in which the skin material 1 and the wadding 2, and the wading 2 and the back base fabric 3 are fused at the fusion part 2a (-
line).

In Figure 2, the epidermis 1 has fine grooves a and b shown in Figure 4.
are arranged in parallel. These grooves a, b
intersects the fusion line A at the Aa and Ab sections. 1st
In the figure, the intersections Aa and Ab are omitted.

FIG. 3 shows an enlarged view of the fusion line A, grooves a, b, intersections Aa, Ab, etc. in FIG. 2.

FIG. 4 is an enlarged view of the cross section taken along the - line in FIG. 3.

In the above, the shape, number, and angle of intersection of the grooves a and b with the fusion line A are not limited to those shown in the drawings, and the fusion line A may be curved. The problem with the above conventional technology is that the skin material 1 is not fused to the wading 2 at the intersections Aa and Ab of the grooves a and b and the fusion line A, or that the skin material 1 is not fused even if it is fused. The strength of the fused part 2a is higher than that of other parts of the fused line A.
The fusion strength is weak and may vary.

The reason for this is: (a) Although not shown in the figure, if compression heating is performed along the fusion line A using, for example, a high frequency type or other heat fusion type,
The intersections Aa and Ab become spaces or
The density of the skin material 1 in the compressed space is lower than that of other skin materials 1 in the welded contact portions. Therefore, when using high frequency fusion,
Frictional loss due to vibration of dielectric molecules is reduced, the amount of heat generated is small, and fusion does not occur or the fusion strength is weak. Even with other heat-sealing types, heat is transferred to the skin material 1,
Since the transmission to the wading 2 and the back base fabric 3 is not possible or is limited at the intersections Aa and Ab, there is a drawback that the fusion strength is weak or no fusion is achieved at the intersections Aa and Ab.

(b) In particular, when the intersection angle between the fusion line A and the groove a or between the fusion line A and the groove b is small, the intersections Aa and Ab become long, and the above-mentioned defects occur to a large extent.

(c) Compared to using low-melting point urethane foam or ordinary urethane foam impregnated with adhesive for wading 2, it is cheaper to use ordinary urethane (the urethane generally used for machine-stitched trim covers). Although urethane has excellent physical properties such as elasticity, it is difficult to fuse it at intersections Aa, Ab, etc. (including the intersection between the recess and the fusion line in (e) below) because it has a high melting point. It is difficult or impossible to do so.

(d) In the case of high-frequency welding, if the skin material is a material with low dielectric loss or a material that easily generates sparks due to high-frequency voltage, such as polypropylene, welding at intersections Aa, Ab, etc. may be particularly difficult. This is not possible, but sparks may occur and damage the epidermis. Alternatively, if a flame retardant or other coating is applied to the back side of the skin, sparks may be generated as described above depending on the coating material.

(e) Fig. 5 shows a case where there is a recess C in the skin 1. Although illustration is omitted, if the fusion line A in Fig. 3 straddles the recess C, similar to the above, for example, it is not possible to fuse the recess C. Strength is weak.

Although the recess C is not shown, the epidermis 1
is a knitted fabric such as mokettu, whose surface has a pattern,
The same drawbacks as described above occur when the skin 1 has a large number of irregularities with a smaller area than the concave part C in FIG. 5 due to the pattern, the thickness of the thread used, the roughness of the weave, or other reasons. The same applies even if there are uneven portions on the back side of the skin material 1. Furthermore, although not shown in the figure, since threads and fibers are used on the surface of general knitted fabrics, woven fabrics, and non-woven fabrics, there are small irregularities on the entire surface and spaces between the threads, so conventional fusion fabrics The adhesion method may have low fusion strength. Furthermore, the same drawbacks as described above occur when a gap is created between two or more overlapping skins.

(f) When the skin 1 is made of textiles or the like, if a metal thread material is added to the materials used for dyeing, that part may be destroyed by sparks caused by high frequency current.

(g) As mentioned above, when fusion cannot be achieved by high frequency or other means, conventionally there was a drawback in that the user had no choice but to resort to time-consuming sewing using a sewing machine.

The present invention has been made in order to overcome the drawbacks of the above-mentioned conventional examples.In the past, it was impossible to fuse the trim cover due to the material, shape, smoothness, coating material, etc. of the skin material, but by using the ultrasonic welding method, The object of the present invention is to provide a method and product for fusing three layers: a skin material, wadding, and a backing fabric.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. 6 to 8.

In FIG. 6, the outer skin 1, the wading 2 and the back base fabric 3 are overlapped, and the grooves a shown in FIGS.
An ultrasonic horn pedestal 5 (the thickness of which is indicated by the width t of the dotted hatch) is located below the grooves a and b.
It is placed along the fusion line A intersecting b. There is an intersection between the ultrasonic horn pedestal 5 and grooves a and b.
A space is created between Aa and Ab.

Pressure is applied to the ultrasonic horn mold 4 (its thickness is indicated by the width T of the dotted hatch), compressing the space between the ultrasonic horn pedestals 5, and applying ultrasonic vibration to the ultrasonic horn mold 4. When given, the vibration waves of the ultrasonic horn mold 4 are transmitted to the wading 2 through the back base fabric 1, and the vibrations are transmitted to the intersections Aa and Ab of the skin 1. The wading 2 part below the ultrasonic horn type 4 has the effect of transmitting ultrasonic vibrations over the entire surface, and is further compressed by the ultrasonic horn type 4, so the skin material 1 is compressed, and the space between the intersections Aa and Ab is upward. When the ultrasonic horn type 4 is pushed up by the elasticity of the wading 2, the vibrations of the ultrasonic horn type 4 are directly transmitted to the intersections Aa and Ab by the wading 2. The lower wading 2 is melted.
At the same time, the ultrasonic vibrations also melt the skin 1 due to the transmission effect or direct effect, and the skin 1 is fused at the fusion portion 2a of the fusion line A in FIG. 1.

In this case, if the skin 1 is made of a material that generates heat due to ultrasonic vibration, the skin 1 in contact with the ultrasonic horn holder 5 will melt or soften, and the pressure of the ultrasonic horn mold 4 will cause the ultrasonic horn holder 4 to melt or soften. is the fused part Aa,
Contacting the bottom of Ab, directly transmitting the vibration from above, the skin material 1, wading 2 and back base fabric 3 generate heat.
Melt and fuse.

Although insulating paper must be used in the case of high frequency fusion, the use of insulating paper is usually not necessary in the ultrasonic fusion of this method. However, depending on the type of material to be welded, it is necessary to promote heat generation, so although not shown, appropriate insulation is provided between the ultrasonic horn mold 4 and the backing fabric 3 to promote heat generation due to ultrasonic vibration. By intervening an object, the fusion effect can be further enhanced. Regarding this method, in the current experiment, the epidermis 1 and the wading 2 are placed on the ultrasonic horn pedestal 5 shown in Fig. 6.
Further, the back base fabric 3 is placed on top of that, and although not shown, a high cross (also called high frequency cross) is formed.
, and then place the Empire Cross on top of it. Empire cloth and high cloth generate heat due to the vibration of the ultrasonic horn mold 4, which promotes heat generation in the outer skin 1, wadding 2, and back base fabric 3. Even though Empire Cloth softens due to heat generation, High Cloth is made of cloth coated with silicone, etc., so it is less likely to soften and has good mold releasability. Alternatively, glass fibers coated with a polytetrafluoroethylene resin having excellent heat resistance and mold releasability, or other materials having the same purpose as those mentioned above may also be used. The frequency in this case is 22 KHz in one embodiment.

In FIG. 6, the cross section of the ultrasonic horn pedestal 5 is such that the tip of the ultrasonic horn pedestal 5 forms the fused portion 2a (FIG. 1), as shown by the cross section 5a.

In FIG. 6, the entire diagram may be turned upside down.
Further, since T>t, if the width of the fusion wire is also within the width of T, there is no risk of it coming off.

FIG. 7 shows the cross sections 4A and 5a in FIG. 6, the epidermis 1,
The 7th cross-sectional view corresponds to the wadding 2 and the back base fabric 3.
In the figure, the fused part 5a of the ultrasonic pedestal 5 corresponding to the lower mold
(width t), ultrasonic horn type 4
The width T is the back base fabric 3, wading 2 and outer skin material 1
is compressed and subjected to ultrasonic vibration to form a fused portion 5a (width t).
It is fused with. - of 4A in Figure 8
A line cross section shows 4A in FIG. The ultrasonic horn type 4 shown in FIG. 8 is configured so that the ultrasonic horn type 4 is divided in the longitudinal direction (4A, 4B, 4C, etc.) and vibrates separately. 7 and 8 may all be turned upside down. Furthermore, if the fusion wire is short, the ultrasonic horn type 4 should not be divided into 1 parts as described above.
Your body is fine.

Next, the functions and effects of the present invention will be described.

In the case of the above high frequency fusion, the intersection Aa, Ab
Depending on the space, as described in (a), (b), (c), (d) or (e) above, the wading 2 was not fused or the fusion strength was weak. Similar results are obtained with general heat fusion. Furthermore, as described in (c), (d), (f), and (g) above, materials with low dielectric loss resistance or materials that generate sparks due to electric current, and even the wading 2 of ordinary urethane described above, can be used with conventional high-frequency welding. Although fusion cannot be achieved using this method, it is possible to achieve fusion with the required strength using the ultrasonic method of the present invention.

The above method can of course be used even when the surface has fine irregularities such as embossing, or when the surface has no irregularities and is smooth.

In addition, there is no wear and tear on auxiliary materials such as insulating paper used for high-frequency welding, and even if there is, there is very little wear and tear, and defects do not occur much, the cost is low, and the welding strength is strong.
And you can get beautiful products.

The manufacturing method and product according to the present invention described above are not limited to trim covers. For example, if hardboard or the like is used for the body of the backing fabric shown in Fig. 1, it can be applied to a door pad for a vehicle. It can also be applied to interior items, furniture, and other interior items.

[Brief explanation of drawings]

1 to 5 relate to the conventional example, in which FIG. 1 is a sectional view of the trim cover taken along the line - in FIG. 2, FIG. 2 is a partial plan view of the trim cover, and FIG. Wire attachment A, grooves a and b, and intersection Aa,
FIG. 4 is a cross-sectional view taken along the - line in FIG. 3, FIG. 5 is a plan view showing the skin recess, and FIGS. FIG. 7 is a cross-sectional view showing the manufacturing method, the relationship between the ultrasonic horn mold, the ultrasonic horn pedestal, and the trim cover, and FIG. 8 is a cross-sectional view taken along the - line arrow in FIG. 7. 1... Outer skin, 2... Wading, 2a... Fusion part, 3... Back base fabric, 4, 4A, 4B, 4C... Ultrasonic horn type, 5... Ultrasonic horn pedestal, A...
Fusion lines, a, b...grooves in the epidermis, Aa, Ab...intersections.

Claims (1)

[Claims] 1. A trim cover in which three layers are stacked: an upper skin material, a middle layer of wadding made of ordinary urethane, and a lower backing fabric, and the parts that need to be fused are heated and fused by ultrasonic vibration. In the manufacturing method, the skin material, wading, and backing fabric are placed on top of each other in this order on an ultrasonic pedestal that has a fused part with the required fused shape, and the required parts are compressed using a divided ultrasonic horn mold. A method for producing a trim cover characterized by fusion of necessary parts by applying sonic vibration. 2. In a trim cover in which three layers of a skin material with uneven surfaces, ordinary urethane wading, and a backing fabric are stacked and fused together by heating the parts that require fusion using ultrasonic vibrations, the fusion of the three layers is performed. A trim cover made by ultrasonic welding, characterized in that the three layers are fused to each other by compressing the parts that need to be attached and flattening the uneven parts of the skin material using an ultrasonic horn type.