JPH09239091A - Snow retaining mat for laying in skiing ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet which plays the role of a thermal insulating layer from terrestrial heat when laid on a road ground surface so as to be efficiently laden with snow by partially joining a sheet-like material made of a water permeable synthetic resin and a non-woven fabric made of a synthetic resin having prescribed void volume to form a laminate and specifying the thickness over the entire part thereof to a prescribed size. SOLUTION: This snow retaining mat 1 for laying in a skiing ground consists of the two-layered structure composed the non-woven fabric 3 and the sheet-like material 2 and is used by laying the sheet on the base ground of the skiing ground by positioning the non-woven fabric 3 as a front side and the surface of the sheet-like material 2 as a rear side. The layer by the non-woven fabric 3 acts to maintain the temp. of the front layer of the non-woven fabric 3 on the front layer like the outdoor air temp. by insulating the terrestrial heat. The layer consisting of the sheet-like material 2 reinforces the non-woven fabric 3 and assures water passage holes 5 which are the routes to permeate and absorb the water melting from the snow to the ground surface. The sheet-like material 2 made of such water permeable synthetic resin and the non-woven fabric 3 made of the synthetic resin fibers having the void volume of 20 to 200kg/m<2> are partially joined to form the laminate and the thickness over the entire part thereof is specified to 2 to 10mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mat to be laid on a ski field base prior to snowfall.

[0002]

2. Description of the Related Art Conventionally, a ski field constitutes a sliding surface which causes snow to fall on a sloped dew ground directly by snowfall. by the way,
Since the temperature of the open-air surface is higher than the atmospheric temperature due to geothermal heat, the snowfall melts when it comes into contact with the open-air surface, and the heat of melting at that time is almost the same, and a large amount of snowfall is required to continue snowfall for a long time to accumulate snow. ing.

[0003]

[0004] Although nets have been laid on the surface layer of the base, which becomes a gliding surface due to snow accumulation, for the purpose of increasing the resistance due to the frictional force with the accumulated snow and suppressing the occurrence of avalanches, Most of the open ground is open.
Therefore, an object of the present invention is to provide a member that is laid on the open ground and plays a role of a heat insulating layer with the geothermal heat to efficiently cover snow.

[0004]

According to the present invention, a synthetic resin sheet 2 which can pass water and a synthetic resin fiber type nonwoven fabric 3 having a porosity of 20 to 200 kg / m ³ are partially joined. And a total thickness of 2 to 10 mm, which is a snow retaining mat for ski field laying.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The snow retaining mat of the present invention has a two-layer structure composed of a non-woven fabric and a sheet-like material, and is laid with the non-woven fabric surface as the front side and the sheet-like surface as the back side on a ski field base. Is done. The non-woven fabric layer acts to block the geothermal heat and keep the surface temperature of the non-woven fabric surface at the same level as the outside air temperature.
The layer formed by the tooth-like material reinforces the non-woven fabric and secures a path for permeating and absorbing the water melted by the snow.

The non-woven fabric is a fiber-based aggregate and is classified according to the type and manufacturing method of the fiber. In this case, the direct spinning method or the direct spinning method is used because of the large specification selection range of thickness, porosity and basis weight. Generally, a dry non-woven fabric, which comprises a spinning step of forming a fiber web by a card or air flow method and a bonding step of forming the fiber web into a bonding sheet with a binder or heat, is preferably used. Examples of this type of nonwoven fabric include spunbond, resin bond, stitch bond, thermal bond, spunlace,
Examples include a needle punch nonwoven fabric. This fiber type is preferably made of synthetic resin in terms of durability, strength, non-water absorption, low heat capacity, and low thermal conductivity, and polyester type, polyamide type, polyolefin type, polyvinyl chloride type, polyvinylidene chloride type There is no particular limitation.

The porosity of the non-woven fabric can be rephrased as the fiber density, and it is necessary to be in the range of 20 to 200 kg / m ³ , and more preferably 50 to 100 kg / m ³ . This is limited by the ability to capture snowfall and the water permeability of snow melting water, and the low porosity nonwoven fabric has poor water permeability and lacks flexibility and is inconvenient to handle. The low strength causes a problem in workability.

The sheet-like material is used to reinforce a non-woven fabric, and is made of a synthetic resin monofilament, multifilament, flat yarn, split yarn or the like, which has been imparted with high strength by drawing or the like. The sheet is made waterproof by knitting or woven fabric or resin coating or the like, and a large number of water permeation holes are opened by physical perforation so that water can pass through. This is because the water that has melted snow on the surface of the snow-retaining mat is permeated and absorbed by the ground to suppress the ice-burning of the surface of the mat.

In order to laminate and bond these non-woven fabric and sheet-like material, an adhesive, a hot melt web, powder fusion or the like is fixed in the middle, or a resin which can be heat fused to the non-woven fabric. Of a sheet-like material knitted in a coarse state using a composite fibrous or composite yarn composed of an outer layer and a higher melting point resin inner layer than the outer layer to be fixed by heat fusion Any means can be adopted, but in any case, a dot-shaped, band-shaped, grid-shaped, or other partial joining method is employed so that the joining portion does not cause a large decrease in water permeability of the snow retaining mat.

The snow retaining mat having such a structure needs to have a total thickness of 2 to 10 mm, and more preferably 3
It has a thickness of about 5 mm. This is mainly due to the fact that it acts as a heat insulating layer and is easy to handle. If the thickness is less than 2 mm, the geothermal heat will be further transferred from the sheet-like material to the nonwoven fabric and the surface temperature will rise. Therefore, the purpose of the heat insulation effect is not achieved, while a thick material exceeding 10 mm becomes bulky and is relatively wide, and as a snow retaining mat used as a long object, it hinders handling during storage, transportation, and laying work. It comes.

[0011]

[Embodiment] Hereinafter, an embodiment will be described.

Example 1 Polypropylene (MI = 1.5) was selected as the thermoplastic synthetic resin,
After extruding in an amorphous state from a die at a melting temperature of 240 ° C by an inflation method and air-cooling to form a film,
It is cut into a tape shape and the drawing temperature is set by the contact hot plate drawing method.
132 ° C, annealing temperature 141 ° C, longitudinally uniaxially stretched at a draw ratio of 5.8 times, and a split yarn with a fineness of 1,350 dr that was split and raised by contacting with a high-speed rotary blade roll. Manufactured. This split yarn was used as warp and weft, and a woven fabric which was plain woven with a sulzer loom at a weaving density of 8 × 8 yarns / inch was used as a sheet 2.

As the non-woven fabric 3, a polypropylene spun-bonded non-woven fabric (basis weight: 180 g / m ² , porosity: 100 kg / m ³ ) is selected, and the non-woven fabric 3 is embossed with unevenness at 10 mm intervals.
A hot-melted vinyl acetate-based hot melt adhesive is applied in spots using a roll, and the sheet-like material 2 is polymerized and pressure-bonded by a heating roll to fix at a partial joint 4. Thus, a laminate having a tensile strength of 50 kgf / 5 cm was obtained.

This laminate was cut and the peripheral portion was folded back and sewn by 30 mm, and the folded back portion was subjected to eyelet processing at intervals of about 90 cm, and the total thickness was 2.2 mm. The snow retaining mat 1 for laying ski fields was used.

EXAMPLE 2 A multi-filament knitted fabric made of polyethylene terephthalate was coated with polyvinyl chloride resin on an air-impermeable tarpaulin sheet, and water holes 5 having a diameter of about 8 mm were formed in a zigzag pattern at intervals of 75 mm. A sheet-like material 2 was obtained by perforating the entire surface to allow water to pass therethrough.

As the non-woven fabric 3, a resin-bonded non-woven fabric made of polyester synthetic resin (basis weight: 400 g / m ² , porosity: 50 kg / m ³ )
A low-melting point hot melt web was sandwiched between the non-woven fabric 3 and the sheet-like material 2 and pressure-bonded by a heating roll to fix at a partial joint 4 to obtain a laminate having a tensile strength of 80 kgf / 5 cm. .

This laminate was subjected to the same processing as in Example 1 to obtain Example 2. The snow retaining mat 1 had a total thickness of 9.5 mm.

The snow retaining mats 1 of Examples 1 and 2 were laid on the open ground, fixed by piles through eyelet holes, and the state of snow accumulation was compared with that on the open ground. It was confirmed that many snow layers were formed on the surface of the snow retaining mat, and no ice-burning was observed at the boundary between the snow retaining mat 1 and the snow layer after the passage of time.

[0019]

As described above, since the ski field laying mat of the present invention is a mat having a two-layer structure comprising a synthetic resin non-woven fabric and a sheet-like material, the synthetic resin has a low heat capacity and a low thermal conductivity. And, by controlling the heat of the mat with a specified thickness of the mat and making the surface temperature of the mat almost equal to the outside air temperature, snow melting is suppressed, and the voids in the non-woven fabric improve the catchability of snowfall and form a snow layer efficiently. It can be used as a sliding surface. Also, by having a non-water-absorbing and suitable water permeability, the snow melting water permeates the inside of the mat and is sent to the ground to be absorbed,
It will be effective in suppressing the ice burn. further,
It can be used as a snow-holding mat for ski field laying because it can be used for wide and long items, is easy to handle for storage and transportation, and can be laid by simple work. is there.

[Brief description of drawings]

FIG. 1 is a partially cutaway plan view of a snow retaining mat according to a first embodiment.

FIG. 2 is a partially cutaway plan view of a snow retaining mat according to a second embodiment.

FIG. 3 is a partial sectional view of the snow retaining mat of the present invention.

[Explanation of symbols]

 1 Snow-holding mat 2 Sheet-like material 3 Non-woven fabric 4 Joint part 5 Water passage hole

Claims (1)

[Claims] 1. A synthetic resin sheet-like material 2 which is water permeable,
A laminate obtained by partially joining a synthetic resin fiber-based non-woven fabric 3 having a porosity of 20 to 200 kg / m ³ and a total thickness of 2 to 10 mm.
A snow retaining mat for laying ski areas characterized by the following.