JPH0586037B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a heat generating plate that utilizes heat generated by heating wires and is mainly used in outdoor passageways.

[Prior Art] In areas with snowfall in winter, it may be necessary to secure an outdoor passage for daily life or work. For example, when it is necessary to clear a walkway for daily life, a walkway in a substation or factory premises, or an open space in front of a store, snow accumulation must be removed, so instead of shoveling snow, it is necessary to lay heat-generating plates in the desired locations. It is being done. Heat-generating plates are also sometimes used to collect heat during outdoor work in cold regions.

Heat-generating plates conventionally used for the purpose of melting ice and snow, keeping warm, and heating include heating wires encapsulated in synthetic resin plates, and heating wires enclosed in iron plates as shown in Figure 4 A, B, and C. There are also known products in which the material is pasted and covered with a heat insulating material.

The type shown in Figure 4B is the upper and lower galvanized iron plates 17, 1.
Insulating material 18 is sandwiched between 9 and galvanized iron plate 1 on the heat generating side.
An insulated heating wire 4a is attached directly under the iron plate 17, which receives power from an external power source and generates heat.
This heats the snow to melt snow on the surface.

Furthermore, there is also a conventional technique as shown in FIG. 4C, which is intended only for indoor heat retention and heating. This is a technology disclosed in Japanese Utility Model Application Publication No. 58-51118, and is an indoor floor heating system in which a heating wire 4a is wrapped in a mortar layer 3a and a tile 20 is attached to the top surface. The silicone adhesive 21 is used to prevent the tiles from coming off or peeling off from the mortar due to cycles or short shocks due to its flexibility.

[Problems to be Solved by the Invention] Among conventional heating wire type heating plates, those using synthetic resin have inferior strength and rigidity, so their use is limited to places with light loads such as indoors and roofs. According to JIS regulations, the strength of polyethylene material, the most well-known synthetic resin, is only 60 to 200 kgf/cm ² , polypropylene is almost the same, and rigid vinyl chloride has a maximum strength of over 6 kgf/mm ² , but with the addition of heat. It is inappropriate to use it under conditions where the temperature rises. Therefore, even if the board is thick enough to provide deflection strength in places such as roads where it must withstand the weight of a vehicle, there is still a risk and one must hesitate to implement it.

In addition, products using iron plates can take advantage of the high strength of iron materials, but if used outdoors or in a humid atmosphere, corrosion will progress and the service life will be significantly shortened. Even if anti-rust paint is applied regularly, if the exposed surface is large, maintenance will be a heavy burden.

Furthermore, the mortar-based floor heating cited at the end is limited to indoor use, and cannot be used outdoors under harsh conditions.
For example, cement mortar itself has a compressive strength of 100
~600Kgf/cm ² , and the tensile strength is about 10-40Kgf/cm ² , but the surface layer sandwiching the heating wire is too fragile if it is made of tiles or adhesive alone.

For use on outdoor roads, etc., it is laid on the surface of the road so that even when heavy trucks pass over it, there is no risk of minor cracks occurring, and therefore there is no risk of rainwater infiltrating through the cracks. This is an absolutely necessary condition to prevent electric shocks to passersby, and it is difficult to guarantee this condition over a long period of time using any of the conventional techniques.

It is relatively easy for those skilled in the art to come up with the idea of choosing press-formed reinforced plastic material as a material with excellent corrosion resistance and strength that can withstand high loads and burying heating wires within a single board. However, in this case, a large amount of expensive reinforced plastic must be used, which inevitably increases material costs. If a product is to be adopted in large quantities, the problem remains that the economic burden is heavy and the scope of adoption is greatly restricted.

In order to solve the above problems, the present invention has high strength and rigidity that can withstand heavy loads such as vehicles, and also has flexibility that can withstand sudden shocks.
The objective is to develop a surface heater for outdoor use that has sufficient chemical stability to withstand harsh outdoor natural conditions, such as flooding, snow, sunlight, and freezing.

[Means for Solving the Problems] The heat-generating plate according to the present invention, which is mainly used in outdoor passageways, is composed of two sheets of long glass fiber cloth impregnated with a resin liquid that is pressed under a reinforced plastic layer containing short glass fibers dispersed therein. or a surface layer 1 made of heating wires sandwiched at the top and bottom between nonwoven fabrics 5A and 5B;
An intermediate layer 3 made of resin mortar that is pressed to the surface layer 1; at least one sheet of long glass fiber cloth or nonwoven fabric 5 that is pressed to the intermediate layer 3 and impregnated with a resin liquid; and short glass fibers that are pressed to this are dispersed. The above-mentioned problem has been solved by forming the back layer 2, which is made of a reinforced plastic layer.

More specifically, it is desirable to use a heat-generating plate that has been subjected to secondary processing such as drilling, notching, cutting, etc. to match the shape of the installation location at the site.

In addition, in the method of manufacturing this heat generating plate, a sheet-like uncured reinforced plastic molding material 14 containing short glass fibers dispersed therein and at least one sheet of long glass fiber cloth impregnated with resin liquid are placed in the lower mold of the mold. Alternatively, the heating wire 4 is temporarily sewn to either the nonwoven fabric 5, a paste-like resin mortar material 3 made by mixing and kneading resin, two long glass fiber cloths impregnated with resin liquid, or the nonwoven fabrics 5A and 5B. The sandwiched material and the sheet-like uncured reinforced plastic molding material 14 containing dispersed short glass fibers are accumulated in this order, and the upper mold of the mold is placed on top of this accumulation, and the material is press-molded while being heated and cured. Able to solve problems.

[Function] The heat generating plate of the present invention is shown in FIG. 1 and FIG.
As shown in the figure, a heating wire, which is a heating element, is built into the board, so when it receives power from an external power source, it generates heat and heats the board. Therefore, it functions to melt snow on the board and provide heat to outdoor workers.

Unlike conventional heat generating plates, the heat generating plate of the present invention is mainly intended for use in outdoor passageways.
Both the reinforced plastic layers on both sides and the middle mortar layer have completely different compositions compared to those of the prior art, and therefore their mechanical properties are at a higher level than any of the prior art, and they can withstand the adverse conditions of outdoor exposure. It is characterized by its excellent weather resistance properties.

That is, since the surface directly exposed to the external environment is a reinforced plastic layer formed by high-strength press molding, it has excellent corrosion resistance and there is no need to worry about strength. The internal middle layer uses resin mortar to prevent material costs from rising. Moreover, it is important to consider that among the material strengths, the bending modulus is closely related to outdoor use, and other factors such as tensile strength do not need to be considered. be. In a sandwich structure with resin mortar layers in between, the bending elastic modulus of the resin mortar layer is already high, so there is almost no negative effect of deterioration, and the tensile strength, which decreases almost in proportion to the constituent wall thickness ratio, is a requirement for outdoor use. As long as it is used for this purpose, it can maintain the same service life as if it were constructed entirely from a single sheet of reinforced plastic.

One of the issues when press-molding SMC materials with resin mortar sandwiched between them is that heating wires for heating are placed directly on the uncured mortar layer, and SMC
If the material is placed and heated and pressurized, there is a risk that the heating wire will sink into the resin mortar layer and penetrate deeply into the layer. It goes without saying that the heating plate should be buried as close to the surface as possible and at an almost uniform depth, as long as the heating wires are not exposed, so if this is done, the thermal efficiency will drop significantly and the construction will be poor. Although it could happen,
To prevent the heating wires from digging into the interior even when subjected to strong pressure from the surface, the heating wires are supported with long glass fiber cloth or non-woven fabric to restrain their position, and are tightly crimped to the reinforced plastic layer or resin mortar layer. There is no such fear because the cloth is impregnated with resin liquid.

Furthermore, the heating plate of this invention has high strength and rigidity, and its surface is much more stable than ordinary mortar, so it can be processed without fear of cracking or breaking even when drilling, notching, or cutting is performed. Since there is no surface or rag, it is mass-produced in a factory with standard dimensions,
It also has an advantageous feature in terms of workability, as it can be pre-processed into any shape according to subsequent demand, transported to the site, and easily installed on-site.

[Example] FIGS. 1 and 2 are examples of preferred embodiments of the present invention, and FIG. 3 is an exploded perspective view illustrating the manufacturing method. For convenience of explanation, the manufacturing method shown in FIG. 3 will be described first. There are various molding methods for reinforced plastic (FRP) products, such as the hand lay-up method (where materials are layered and bonded together by hand) and the spray-up method (where materials are sprayed on to increase thickness). However, in the embodiment of the present application, a method was adopted in which the molding material was sandwiched between upper and lower molds and heated and pressed using a press. It goes without saying that press molding (matted die) generally has much higher mechanical strength. Various types of reinforced plastic sheet molding materials for press molding are available, but the one used in this application is one in which short glass fibers are blended with unsaturated polyester resin as a main ingredient and other thickeners, fillers, etc. This is an SMC material that is impregnated with resin liquid and sold as an uncured sheet-like semi-finished product with a glass to resin ratio of approximately 30% to 70%. It has excellent mechanical strength; for example, the manufacturer says that iso-based SMC has a bending strength of 22Kgf/mm ² , a bending elasticity of 1300Kgf/mm ² , a tensile strength of 12Kgf/mm ² , and a compressive strength of 17Kgf/mm ² provided. In the example, this
A long glass fiber cloth or nonwoven fabric 5 impregnated with a resin liquid is brought into contact with the inside of the SMC material 14, and the resin is unsaturated polyester of the same quality as the applied SMC, and the impregnation rate is almost the same. The strength after solidification is considered to be approximately the same level as the SMC mentioned above.

Resin mortar material 3 was a paste-like material prepared by mixing No. 6 silica sand as an aggregate with 10% unsaturated polyester resin in liquid form, and adding some curing catalysts and accelerators. . This mixture is generally called UP concrete, and examples of its strength include compressive strength of 800 to 1600 Kgf/cm ² , tensile strength of 90 to 140 Kgf/cm ² , and bending strength of 140 to 350 Kgf/cm ²
etc. have been reported. In a preferred embodiment, the surface layer and back layer each have a total thickness of approximately 20 mm.
%, and molding with an intermediate layer of 60% yielded good results.

The heating wire 4 is an insulated wire made by extruding ethylene and propylene rubber insulation on a heating element made of a spirally wound copper-nickel resistance wire. An insulated surname is not necessarily a requirement.

In this example, a heating wire of 70Ω/m was used. As a rough guide, 200~ when connected to a 200v power supply
Setting the calorific value of 400Watt/m ² as a standard, it is sewn to one side of the long glass fiber cloth or nonwoven fabric 5 so that it can be arranged at appropriate intervals, so that it does not shift its position or become locally deeply embedded during molding and pressing. This is to ensure that it does not fall too far from the surface.

As shown in Fig. 3, a sheet of uncured material is placed in the concave part of the heated (130 to 150°C) lower press mold 16.
SMC14, impregnated long glass fiber cloth 5A, 5
B, paste-like resin mortar material 3, heating wire 4
The long glass fiber cloth 5B, the impregnated long glass fiber cloth 5A, and the SMC 14 are charged in this order, and the entire body is heated and pressed by the upper mold 15 to react and harden the resin, and heat is generated by integral simultaneous molding. You can get a board.

As shown in Figures 1 and 2, the molded heating plate has a surface layer 1 on its surface (heating surface side) containing heating wires 4 held in reinforced plastic; The plate and the long glass fiber cloth or nonwoven fabric 5 in which the heating wires are arranged almost evenly are integrated, and its strength is much greater than that of ordinary synthetic resin. The middle layer 3 in the center is made of solidified resin cement, and is considerably stronger than a mortar layer made of ordinary Portland cement. Back layer 2 mainly made of reinforced plastic
It is molded using the same manufacturing method as the surface, and although it does not have a built-in heating wire, other conditions are the same as the surface, and the strength remains at the same high level.

After molding the heating plate, a circuit for the heating wires housed inside is formed. Specifically, both ends of the heat generating plate exposed to the outside are connected to a non-heat generating lead wire 6 and further connected to an external power supply wire 7. (The power switch is not shown) Depending on the configuration of the heating element of the heating wire, the lead wire may be omitted. This connection is made within a connection box 8 recessed in one corner of the heat generating plate.

9 is the heating wire 4 and the lead wire 6, 10 is the lead wire 6
This is a crimp connector used to connect the power supply wire 7 and the power supply wire 7, respectively.

The reinforced plastic layer and resin mortar layer on the upper surface of the connection box 8 are cut out at this part.
The reinforced plastic layer on the underside is made up of an integral continuous aperture. After the wires have been connected in the connection box 8, a separately molded cover 11 made of reinforced plastic is attached with screws 12. Anti-slip protrusions 13 are regularly projected on the surface of the surface layer 1 on the side of the heat generating surface to prevent a person from slipping when the heat generating plate is used as a step board.

The heat generating plate of the present application must withstand harsh outdoor conditions and must never cause any personal injury under any circumstances. Therefore, before use, the above-mentioned examples were tested for accuracy as shown in some examples below. Safety has been confirmed.

(a) Normal physical properties (b) Dielectric strength: After being immersed in water for 1 hour, voltage is applied between the live part and the submerged part (c) Repeated pressurization: Press a load of 100 kg repeatedly 100,000 times (d) Repeat Deflection: Apply pressure 100,000 times from above until 5mm deflection occurs (e) Car driving: A chain is attached to the rear wheel of a 10-ton truck loaded with 10 tons of cargo, and it passes back and forth 10 times. Just a small portion of these Although this is just an example, the content and conditions are far more diverse than the conventional tests for so-called surface heaters, and the severity of the tests is extremely severe. It can be used as a

In addition, after shaping it into any desired shape by drilling, notching, or cutting, it can be moved to the site and attached to and removed from the other component by riveting or bolting, and if necessary, non-slip steps can be installed. It can be used in a wide variety of ways, including gluing materials, braille tiles, information signboards, etc.

Some of the examples that can be commended include: (1) Drilling holes in a part of the electric heating plate and fixing it to the existing concrete stage with anchor bolts as a long tile for the stage.

(2) Use as an electric heating plate that also serves as a cover for power cable wiring pits in outdoor substations, etc., and as an inspection passageway.

(3) Use it to prevent icing by attaching and fixing it to the lid or side wall of a drifting snow gutter.

(4) Use as roof and wall materials and as structural materials and electric heating boards.

(5) To be used as a stepping board for steel-framed steps.

(6) To be used for snow melting by installation and installation on railway track surfaces.

and so on.

[Effects of the Invention] Since the heat generating plate according to the present invention has the configuration as described above, it produces the following effects.Firstly, the reinforced plastic and resin mortar that are the constituent members are both materials with excellent corrosion resistance and are used for heat generation. Because heating wires are built into this, it has sufficient durability without corrosion or deterioration problems even when used in humid environments such as snow melting, compared to conventional technology that uses iron plates.

In addition, in terms of strength, it has a three-layer structure with a resin mortar layer between reinforced plastic layers, so from a mechanical standpoint, the efficiency of using the strength members is high.
Even if the thickness of the plate is increased to withstand the weight load of vehicle traffic, this does not become an economical obstacle and prevents implementation, and the problems of the conventional technology, which uses a fully reinforced plastic layer, are solved.

To describe the effects of the manufacturing method, the heat generating plate of the present application uses a heating mold and integrates heating wires between each molding material layer and is integrally molded with a press, so the adhesion between each constituent layer is high and the strength is high. It has a sandwich structure with parts arranged on the inside and outside, so it has high strength and rigidity. It is more stable than conventional technology (combination of iron plates and heat insulating material) because the heating wires incorporated in the layer do not become foreign matter and become loose within the layer, which causes the plate to crack or peel.

Furthermore, if you pre-stretch heating wires around the glass cloth during integral molding and temporarily secure them with adhesive (you can also sew them on with thread), even if the material fluidizes in the mold during heat molding, the heating wires will not work. It has the unique effect that it is not swept away from the desired location and is buried at a substantially constant depth from the surface, creating conditions of use with high thermal efficiency.

This manufacturing method is an independent product suitable for mass production in factories, and it is extremely economical because it is mass produced with several standard specifications and can be freely fabricated to fit the shape of the object to which it is attached before being attached. It is possible to develop a market with excellent characteristics. Particularly on-site, it is a great advantage that on-site work is extremely simple and easy, as all you have to do is attach it to the mating member.

[Brief explanation of the drawing]

Figure 1 is a front view showing an embodiment of the present invention, Figure 2 is a front view showing an embodiment of the present invention;
3 is an exploded perspective view illustrating an embodiment of the manufacturing method, FIGS. 4A and 4B are perspective views and sectional views showing a conventional technique, and FIG. 4C is a sectional view of another conventional technique. A sectional view shown. 1... Surface layer, 2... Back layer, 3... Intermediate layer (paste-like resin mortar material), 4... Heating wire,
5, 5A, 5B...Long fiber glass cloth, 14...
...Sheet-like uncured reinforced plastic molding material.

Claims (1)

[Scope of Claims] 1. Consists of a heating wire sandwiched at the top and bottom between two sheets of long glass fiber cloth or nonwoven fabrics 5A and 5B impregnated with a resin liquid and pressed under a reinforced plastic layer containing short glass fibers dispersed therein. A surface layer 1, an intermediate layer 3 made of resin mortar that is pressed to the surface layer 1, and at least one sheet of long glass fiber cloth or nonwoven fabric 5 that is pressed to the intermediate layer 3 and impregnated with a resin liquid.
and a back layer 2 consisting of a reinforced plastic layer in which short glass fibers are dispersed and bonded to the back layer 2, and the heat generating plate is mainly used in outdoor passageways. 2. A heating plate mainly used in outdoor passageways as set forth in claim 1, which has been subjected to secondary processing such as drilling, notching, cutting, etc. to match the shape of the installation location at the site. 3 In the lower mold of the mold, a sheet-like uncured reinforced plastic molding material 14 with short glass fibers dispersed therein;
At least one long glass fiber cloth or nonwoven fabric 5 impregnated with a resin liquid, a paste-like resin mortar material 3 mixed and kneaded with a resin, 2 impregnated with a resin liquid
Sheet of long glass fiber cloth or non-woven fabric 5A, 5B
A heating wire 4 is temporarily sewn to one of the two and sandwiched between the two, and a sheet-like uncured reinforced plastic molding material 14 containing dispersed short glass fibers is accumulated in this order, and the upper mold of the mold is attached to this. A method for manufacturing a heat-generating plate mainly used in outdoor passageways, which is characterized by stacking one on top of the other and press-molding while heating and curing.