JPS6217257A - Vertical trough - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a downpipe with excellent cold resistance.

[Conventional technology]

Traditionally, downpipes were made of polyvinyl chloride resin, aluminum, copper, iron, etc. in a cylindrical shape, but in cold regions such as Hokkaido, it is difficult to install these downpipes outside the house. In the winter, rainwater flowing into the downspout freezes and expands, destroying the downspout. In an attempt to prevent this, insulation was wrapped around the outer circumference of the downspouts, but this was ineffective on extremely cold days and the pipes ended up freezing and breaking. Therefore, in cold regions,
It was common practice not to install downpipes outside the house.

As a way to solve this problem,
As described in Publication No. 4, an antifreeze heater is attached to the downpipe, and as described in Utility Model Application Publication No. 54-110232, in addition to the antifreeze heater, the outer periphery of the downpipe is installed. It is known that a foamed synthetic resin outer tube is laminated on top of the outer tube.

[Problem that the invention seeks to solve]

However, the above-mentioned conventional downpipe has a complicated structure due to the use of an anti-freezing heater, and also increases electric heating costs.
Furthermore, in the event of a power outage, the antifreeze heater does not work, resulting in the downpipe being damaged by freezing.

The present invention has been made for the purpose of solving the above-mentioned problems of the conventional downpipe, and providing a downpipe that has a simple structure and is free from freeze damage.

[Means for solving problems]

In order to achieve the above object, the present invention has the following configurations:
A vertical gutter is formed by providing a waterproof layer on the inner circumferential surface of an elastic cylindrical foam body and a protective layer on the outer circumferential surface.

[Effect]

Rainwater flows along the waterproof layer on the inner circumferential surface of the downpipe.

Even in winter, since the downpipe is made of foam, rainwater flowing through the downpipe is insulated and kept warm by the air inside the foam, making it difficult to freeze. Even if rainwater freezes and expands in volume within the downpipe, the elastic foam will absorb this volumetric expansion and will not destroy the downpipe. The protective layer on the outer circumferential surface of the trough prevents the trough from being damaged or deformed.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a downpipe according to the present invention.

Reference numeral 1 designates a downpipe, which is made of an elastic cylindrical foam 2, with a waterproof layer 3 provided on its inner circumferential surface and a protective layer 4 provided on its outer circumferential surface.
is provided.

The cylindrical foam 2 has such elasticity that it can absorb rainwater when it freezes and expands within the downpipe 1. When water freezes and becomes ice, it expands in volume by about 9%, so the foam 2 is preferably one in which the foam layer 21 and waterproof layer 3 are compressed by 10% or more and shrink in volume.

In particular, when considering the case where rainwater is trapped and freezes inside the vertical gutter, the direction perpendicular to the axis of the vertical gutter (thickness direction)
It is preferable that the material can be compressed by 5% or more. The foam 2 preferably has a compression set (JIS K 6767) of 30% or less so that it can withstand repeated freezing and thawing of rainwater.

In addition, in order to prevent rainwater from freezing, the foam layer 21 should preferably have a high heat retention property, and if it is made of synthetic resin, the apparent density will be in the range of 0.01 to 0.6 g/aJ. Preferably. As for the cell structure of the foam layer 21, closed cells are preferable to open cells because they have better heat retention and rainwater does not penetrate into the foam layer 21 even if the waterproof layer 3 is damaged.

The waterproof layer 3 is formed inside the foam layer 21 and has a vertical Al
The membrane layer prevents rainwater from penetrating into the foam layer 21 when it flows inside. The thickness of the waterproof layer 21 should be set to 1 for strength, since garbage, etc. flows along with rainwater in the downpipe 1.
00 μm or more is preferable.

The protective layer 4 has such hardness that the outer surface of the downspout 1 will not be damaged. The protective layer 4 preferably has a thickness of 200 μm or more, depending on the material used, from the viewpoint of strength.

The wall thickness of the downpipe 1 is preferably in the range of 2 to 25 mm, considering the above-mentioned freeze expansion absorption and heat retention.

To form this downpipe, for example, a synthetic resin such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyurethane, or rubber is formed into a cylindrical shape by extrusion foam molding to form an elastic foam. , a relatively thin skin layer may be formed on the inner peripheral surface, and a relatively thick skin layer may be formed on the outer peripheral surface.

Then, the skin layer on the inner peripheral surface becomes the waterproof layer 3, and the skin layer on the outer peripheral surface becomes the protective layer 4.

Further, the waterproof layer 3 and the protective layer 4 may be separately formed by extrusion coating on the inner peripheral surface and the outer peripheral surface of the foam layer 21.

Next, we will explain the results of a freeze-fracture experiment conducted after fabricating a vertical trough.

Example 1 Low-density polyethylene was used as the main raw material, fed to an extruder, dichlorotetrafluoroethane was injected as a blowing agent midway through the extruder, extruded from the extruder into a cylindrical shape, and the inner surface was air-filled from the inside. and extrusion foaming was performed while cooling the outer surface in a cooling mold following the extruder to produce a cylindrical foam.

The cylindrical foam has a closed cell structure, has an inner diameter of 58 mm and a wall thickness of 10 m, and has a 200 μm skin layer as a waterproof layer on the inner circumferential surface, and a skin layer as a protective layer on the outer circumferential surface. A 500μ thick layer was formed. The foam can be compressed by more than 50% in the thickness direction, and the compression set is 3%.
The apparent density of the foam layer was 0.2 g/d. This cylindrical foam was used as a downpipe.

On the other hand, as Comparative Example 1, a down pipe made of hard vinyl chloride resin with an outer diameter of 60 m and a wall thickness of 1°1 was used, and as a Comparative Example 2, an outer diameter of 60 m
An aluminum downpipe with a length of 0 m and a wall thickness of 1.0 m was prepared.

Then, as shown in Figure 2, these downpipes with a length of 1 m were placed in a container 5 containing water and left at -50°C for 2 hours to freeze about 20cm of the lower part of the downpipe. Ta. Next, as a heat insulating material, polyethylene foam (apparent density 0.04) with a width of 40 aa and a thickness of about 3 mm was wrapped around the outside of the center of the downpipe about 8 times (thickness of about 24 mm), and inside the downpipe. was filled with water and left in a -50°C freezer for 17 hours.

As a result, the water in the downpipe freezes starting from the top and ends with the insulation, leaving no place for the volumetric expansion caused by the freezing of the insulation to escape. Vinyl resin downpipe burst into pieces, Comparative Example 2
The aluminum downspout burst when the insulation was wrapped around it. However, in the downspout of Example 1, no abnormality was observed on the outer circumferential surface. When we tried to melt the ice inside the downspout of Example 1, no abnormality was found on the inner peripheral surface.

Therefore, the above-mentioned freezing and thawing experiment was repeated 30 times for the downspout of Example 1, but no abnormality was observed on the outer circumferential surface, and only a few depressions were observed on the inner circumferential surface, making it difficult to use. It was not something that had any influence.

Next, in Sapporo City, Hokkaido, when the vertical gutter of Example 1, the vertical gutter of Comparative Example 1, and the vertical gutter of Comparative Example 2 were installed in a house, 60.
In the winter of 2017, no abnormality was observed in the downspouts of Example 1, but the downspouts of Comparative Examples 1 and 2 burst due to freezing.

In the above example, a protective layer made of the same polyethylene was provided on the outer circumferential surface of the foam layer made of low-density polyethylene, but the protective layer may also be made of a metal such as copper for decorative purposes. good.

〔Effect of the invention〕

As described above, the downpipe of the present invention is formed by providing a waterproof layer on the inner circumferential surface of an elastic cylindrical foam body and a protective layer on the outer circumferential surface. The foam acts as a downpipe, and the foam's insulation and heat retention ability alleviates the freezing of rainwater flowing through the downpipe, and the foam's elasticity absorbs the volumetric expansion of frozen rainwater, causing the downpipe itself to break. never be done.

Therefore, the downpipe of the present invention can be suitably used in cold regions such as Hokkaido.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing one embodiment of the downpipe of the present invention;
The figure is a sectional view illustrating a freezing experiment of a downpipe according to the present invention. DESCRIPTION OF SYMBOLS 1... Downpipe, 2... Cylindrical foam, 21... Foam layer, 3... Waterproof layer, 4... Protective layer.

Claims (1)

[Scope of Claims] 1. A downpipe formed by providing a waterproof layer on the inner peripheral surface of an elastic cylindrical foam body and providing a protective layer on the outer peripheral surface. 2. The vertical gutter according to claim 1, wherein the foam can be compressed by 5% or more in the thickness direction from the waterproof layer side. 3. Claim 1, wherein the foam has a compression set of 30% or less in the thickness direction from the waterproof layer side.
The vertical gutter described in paragraph 2 or paragraph 2. 4. The vertical gutter according to claim 1, 2 or 3, wherein the foam has a closed cell structure. 5. The thickness of the foam is in the range of 2 mm to 25 mm, the thickness of the waterproof layer is 100 μm or more, and the thickness of the protective layer is 2 mm.
The vertical trough according to claim 1, 2, 3, or 4, which has a diameter of 00 μm or more.