JPS6020735Y2 - Cylindrical body for architectural construction - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cylinder for construction, particularly suitable as a formwork for constructing concrete columns underwater or for forming cylindrical cavities in concrete.

Conventionally, paper tubes made by wrapping and stacking paper strips in a spiral shape are lightweight and easy to handle, and are widely used as formwork for forming concrete columns. In some cases, a waterproofing agent is applied to the surface to make it water resistant, but this does not prevent water absorption, resulting in the paper tube becoming soft and significantly reducing its strength, making it impossible to maintain the specified shape as a formwork. .

Therefore, as disclosed in Japanese Utility Model Publication No. 51-51783, it has been proposed to provide a paper tube with a waterproof layer such as synthetic resin, wax, or asphalt by coating or impregnating it on both the inside and outside surfaces in advance. However, if there is unevenness, water can easily penetrate there, and it is also easy to get scratched during handling, so water can easily penetrate there.

The present invention solves these problems and provides a cylindrical body for building construction with no water penetration. The outer surface is coated with a water-impermeable thin plate made of metal with a water-resistant adhesive layer.

Next, a specific example of the present invention will be explained based on the drawings.The present invention is characterized in that the inner and outer surfaces of the paper tube 2, which is formed by spirally wrapping and laminating multiple layers of the paper strip 1, are It is constructed by wrapping a water-impermeable thin plate 3 made of a metal such as the like in a spiral shape with a water-resistant adhesive layer 4.

In the present invention, paper such as kraft paper or board paper is used as the paper strip 1, but synthetic paper such as paper strip 1 is coated with a synthetic resin film 5 such as polyethylene or polypropylene on one or both sides. Resin-treated paper band (Fig. 3,
(Fig. 4), a waterproof paper strip impregnated with or coated with a waterproof material 6 such as wax or paraffin (Fig. 5), and a composite of polyethylene, polypropylene, etc. between the two paper strips 1, 1. Waterproof layer 7 made of resin, wax, paraffin, etc.
It is also advantageous because it has waterproof properties (FIG. 6).

In addition, the ice resistance can be further increased by laminating and covering the outer periphery of the water-impermeable thin plate 3 with a metal foil 8 such as aluminum foil with a water-resistant adhesive layer 4 (No. 7
figure).

Here, the water-resistant adhesive layer 4 is acrylic, epoxy,
It is formed using an emulsion type or solvent type adhesive such as inmoanate type adhesive, or a hot melt type adhesive.

Further, the wall thickness of the cylinder according to the present invention is about 1 to 3-
The thickness of the impermeable thin plate 3 is approximately 0.01 to 0.5 mm, and the amount of adhesive forming the water-resistant adhesive layer 4 is approximately 20 to 0.5 mm.
It is about 500f/d.

As described above, the present invention is a paper tube formed by spirally wrapping and laminating multiple layers of paper strips, and the inner and outer surfaces of the paper tube are coated with water-impermeable thin metal plates with a water-resistant adhesive layer. Because of this, it is possible to provide excellent waterproof properties without losing the characteristics of paper tubes, which are lightweight and easy to handle.

In other words, since the inside and outside surfaces of the paper tube are double covered with different materials: thin metal plates and water-resistant adhesive, at least one of them will not be eroded even in acidic or alkaline water, and the surface will remain intact. Even if the adhesive layer is uneven, the thin metal plate of 2019 prevents water from penetrating through it, does not become damaged during handling and loses its waterproof properties, and peels easily from concrete, so it can be used underwater. When constructing a concrete column or forming a cylindrical cavity in concrete, there is no need to worry about the paper tube absorbing water and softening, and the necessary strength as a formwork for pouring concrete can be maintained.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front partial view of a specific example of the present invention, Fig. 2 is an enlarged sectional partial view thereof, Figs. 3, 4, 5,
FIG. 6 is an enlarged partial sectional view of four types of paper strips, and FIG. 7 is an enlarged partial sectional view of another specific example of the present invention. 1... Paper band, 2... Paper tube, 3...
... Impermeable thin plate, 4... Water-resistant adhesive layer.

Claims (1)

[Scope of utility model registration request] Water-impermeable thin plates 3 made of metal are placed on the inner and outer surfaces of a paper tube 2 formed by spirally wrapping and laminating a plurality of paper strips 1.
A cylindrical body for architectural construction, which is adhesively coated with a water-resistant adhesive layer 4.