JP2750649B2 - Diffuse-reflective sheet and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diffusely reflecting sheet suitable for agriculture such as orchards and greenhouses, for packing fruits, and a method for producing the same.

[0002]

2. Description of the Related Art In order to improve the color of cultivated fruits and improve the quality of the fruits, for example, Japanese Utility Model Publication No. 57-23150,
As shown in Japanese Utility Model Application Laid-Open No. 61-146147, a sheet excellent in light reflectivity has been used. These conventional reflective sheets are configured by laminating a metal foil (aluminum foil) to a base cloth woven by a tape-like thread such as a slit yarn in order to obtain diffuse reflection of light.

A reflective heat insulating sheet formed by laminating a soft synthetic resin film having a metal vapor-deposited film layer on one surface on a foam is described in Japanese Utility Model Laid-Open No. 57-174036. Various sheets utilizing the light reflectivity of the film are already known.

[0004]

However, various types of conventionally known reflective sheets are, for example, the above-mentioned Japanese Utility Model Publication No. 57-23150 for agricultural sheets used for the purpose of improving the coloring of fruits. As described in the official gazette, the base material is a woven fabric woven with a tape-like thread such as a slit yarn or a film as shown in Japanese Utility Model Laid-Open No. 55-81031. However, there is almost no cushioning property, and when the fruit falls due to unexpected strong wind, the fruit is damaged and the commercial value is remarkably reduced.

[0005] This inconvenience is caused, for example, in Japanese Utility Model Laid-Open No.
Although it can be improved by using a cushion body such as an air mat as a base material as proposed in Japanese Patent No. 837, a reflective sheet having such a structure is extremely expensive and is suitable for laying a vast farm. Not only is it uneconomical, it is not only difficult to repair, but also the installation and storage management becomes inconvenient.

SUMMARY OF THE INVENTION The present invention provides a reflective sheet which is flexible and lightweight, has a suitable cushioning property, and is also rich in diffused light reflection, and a method for producing the same.

[0007]

According to the present invention, a polyurethane foam sheet is interposed between a metal foil and a heat-shrinkable base cloth, and random irregularities are formed on the metal foil by heat shrinkage of the base cloth. The above problem has been solved. That is, the irregularly reflective sheet of the present invention is obtained by laminating a metal foil on the surface of a polyurethane foam sheet and laminating a heat-shrinkable base cloth on the back surface of the polyurethane foam sheet.
The back fabric is heat-shrinked to form irregular wrinkle-like irregularities on the front metal foil via the polyurethane foam sheet.

In the method for producing the polyurethane foam sheet, a gas flame by a burner is applied to one surface of the polyurethane foam sheet to melt its surface layer. To bond the two together under pressure, and further apply a gas flame by a burner to the other surface of the polyurethane foam sheet to melt its surface layer, and to apply a metal foil or a heat-shrinkable base cloth to the melted surface immediately after melting. The composite sheet is subjected to a heat treatment in an unconstrained state to shrink the heat-shrinkable base fabric, and the shrinkage of the base fabric causes the metal on the surface to pass through the polyurethane foam sheet. It is characterized in that a wrinkle-like irregular uneven pattern is expressed on the foil.

The polyurethane foam sheet applied to the present invention has a thickness of 1 to 10 mm, preferably 2 to 5 mm.
mm. 1 m thick polyurethane foam sheet
When the thickness is less than m, sufficient cushioning properties cannot be obtained, and when the thickness exceeds 10 mm, not only the cost becomes high but also it becomes difficult to form random irregularities rich in irregular reflection on the metal foil.

As the metal foil, an aluminum foil having a glossy tungsten lamp total reflectance of 80% or more and a thickness of 10 to 20 μm is preferable.

The heat-shrinkable base fabric to be bonded to the back of the polyurethane foam sheet may be 5 to 30 in the vertical and horizontal directions at a temperature lower than the melting point of the polyurethane foam sheet.
% Can be applied, but fibers that shrink at a relatively low temperature, for example, coarse woven fabric woven with spun yarn of acrylic fiber or polypropylene fiber, are light, flexible, and inexpensive. Therefore, it can be preferably applied.

Furthermore, when the polyurethane foam sheet is heated to melt its surface, it exhibits the same adhesive performance as an adhesive, so that the above-mentioned base cloth or metal foil can be bonded at a high speed without using an adhesive. Thus, a composite sheet having a three-layer structure consisting of a metal foil / polyurethane foam sheet / base cloth can be efficiently manufactured.

[0013]

When the diffusely reflecting sheet of the present invention is used by laying it under an orchard tree for agricultural use, for example, the metal foil on the surface reflects the sun's rays in random directions to shade the fruit in the shade. Improves and promotes fruit growth. The polyurethane foam sheet in the middle layer prevents the temperature rise and drying of the soil, and also reduces the impact of fruits falling due to strong winds and the like to reduce the degree of damage and suppress the deterioration of the quality of the falling fruits.

Further, the heat-shrinkable base fabric is formed by heat shrinkage.
An irregular concavo-convex pattern is developed without applying a pressing force to the metal foil like an embossing roll and without impairing the gloss of the metal foil. Then, after heat shrinkage, the polyurethane foam sheet has a reinforcing effect. Further, the front and back surfaces of the polyurethane foam sheet exhibit an adhesive ability by heating, and strongly bond the metal foil and the heat-shrinkable base fabric.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings showing the embodiments of the present invention, FIG. 1 shows a cross-sectional view of the irregular reflection sheet of the present invention, (1) is a metal foil, (2) is a polyurethane foam sheet, (3) is a heat-shrinkable base fabric, a metal foil (1) having a thickness of 13 μm and an polyurethane foam sheet (2) having a thickness of 2 mm and a specific gravity of 0.0.
20 heat-fusible flexible polyurethane foam sheets;
A spun yarn of acrylic fiber (cotton count 14 ^S ) is arranged on the warp and the weft as a heat-shrinkable base fabric, and a coarse plain woven fabric having a warp density and a weft density of 17 / inch is used.

As shown in FIG. 1, the irregularly reflective sheet (4) of the present invention has a metal foil (1) bonded to the surface of a polyurethane foam sheet (2) and a heat-resistant sheet on the back of the polyurethane foam sheet (2). A shrinkable base fabric (3) is bonded to the base fabric (3), and the base fabric (3) is thermally shrunk to form irregular wrinkles on the surface of the metal foil (1) on the front side via the polyurethane foam sheet (2). The unevenness (5) is formed.

Subsequently, irregular wrinkles (5) are formed on the metal foil (1) on the front surface as described above, and the polyurethane foam sheet (2) is provided on the intermediate layer, and the base fabric (3) is provided on the back surface. FIG. 2 showing a method for producing a diffusely reflective sheet (4).
Referring to FIG. 4, the polyurethane foam sheet (2) wound up in a roll is pulled out, and the peripheral speed is 40 m / min while adjusting the tension to such an extent that the polyurethane foam sheet (2) does not relax by the sieving tension device (10). The main roll (11) is guided on a rotating main roll (11). In this main roll (11), a gas burner (1) is attached to one surface of the polyurethane foam sheet (2).
A flame is sprayed by 2) to melt the surface of the polyurethane foam sheet (2) to a thickness of about 0.4 to 0.6 mm, thereby exhibiting an adhesive ability. On the other hand, guide rolls (13) (13)
The heat-shrinkable base cloth (3) is pulled out through the main roll (11).
2) Pressure roll (14) located below
And supplied to the surface of the polyurethane foam sheet (2) in the molten state, and the pressure roll (14)
The two sheets (2) and (3) are adhered to each other by the pressurizing action, and then cooled by a cooling roll (15), and the composite sheet (20) is once wound into a roll. At this time, heat shrinkage hardly occurs in the base fabric (3).

Subsequently, this composite sheet (20) was provided with a main roll (11), a gas burner (12), a pressure roll (14), and a cooling roll (15) as shown in FIG. The polyurethane foam sheet (2) is supplied to the apparatus with the surface of the polyurethane foam sheet (2) being adjusted to a tension that does not relax with the surface of the polyurethane foam sheet (2) facing up, and the gas burner (12) is applied to the surface of the polyurethane foam sheet (2) in the same manner as described above.
To melt the surface of the polyurethane foam sheet (2) lightly, and apply a metal foil (1)
And bonded to the polyurethane foam sheet (2) to form a three-layer composite sheet (30) in which the metal foil (1) is adhered to the surface of the polyurethane foam sheet (2) and the base fabric (3) is adhered to the back surface. After cooling, it is wound into a roll.

Thereafter, the composite sheet (3
As shown in FIG. 4, 0) is introduced into a heat treatment apparatus having a heating zone (21) and a cooling zone (22) without restricting shrinkage. That is, the composite sheet (30) is forced into a relaxed state by a feed roll (23) and supplied into the heat treatment apparatus, and the base fabric (3) is moved in the heating zone (21) in both the vertical and horizontal directions. After shrinking, it was cooled and wound up.

The heat-treated composite sheet (30)
The base cloth (3) shrinks about 8% both vertically and horizontally, and the shrinkage of the base cloth (3) spreads to the polyurethane foam sheet (2) and the metal foil (1), and the back side of the base cloth (3) is flat. Irregular reflection sheet (4) having irregularities (5) in the form of wrinkles with a height difference of about 1 to 2 mm was obtained on metal foil (1) on the front side, as shown in FIG. Was done. Moreover, the irregularities (5) are firmly adhered to the polyurethane foam sheet (2) in both the convex portions and the concave portions, so that the irregularities (5)
The cushioning property is provided in all portions of the unevenness (5) which is rich in durability.

Incidentally, the durability of the irregularities (5) of the irregularly reflective sheet (4) obtained by the method of the present invention was tested by the washing method as follows. 1) Washing test based on JIS-L-027.103 Number of times 5 times @ Grade 5 Grade 2) Commercial washing (chlorine-based dry cleaning) test Number of times 1 @ Grade 4 Grade 3) Commercial washing (petroleum) System dry cleaning) Number of tests 1 time ──── Grade 4 (All of the above are grades of the original appearance ratio of 5 grades.)

In the above-described embodiment, the composite sheet (30) having a three-layer structure is bonded to the polyurethane foam sheet (2) and the base fabric (3) in the first step, and then the metal sheet is formed in the second step. The procedure for bonding and manufacturing the foil (1) is described. The polyurethane foam sheet (2) is bonded to the metal foil (1) in the first stage, and the base fabric (3) is bonded in the second stage. However, it is needless to say that the present invention is satisfied, and the two-layer composite sheet (20) obtained in the first step is run without winding, and the metal foil (1) or (3) may be attached.

[0023]

As described above, the light diffusely reflecting sheet (4) of the present invention has a metal foil (1) bonded to the surface of a polyurethane foam sheet (2) and a heat shrinkable sheet on the back surface of the polyurethane foam sheet (2). The base cloth (3) is bonded together, and the base cloth (3) is thermally shrunk to form irregular wrinkle irregularities (5) on the metal foil (1) on the surface. When this reflective sheet is used, for example, for agriculture, under a tree in an orchard with the metal foil (1) side as a surface, the sunlight is diffusely reflected toward fruits in the same manner as a conventional reflective sheet of this type. In addition to improving the color of the cultivated fruits and improving the quality of the fruits, or helping to suppress the evaporation of soil moisture and weeds, the fruits also fall due to sudden storms such as typhoons due to their cushioning properties. Even the falling fruit is big An excellent effect of preventing the situation that wound.

Further, a polyurethane foam sheet (2)
And the base material (3) is flexible and lightweight,
It is easy to handle and can be conveniently used for lining agricultural houses and for packaging fruits that require heat insulation.

In the production of the present invention, a three-layer composite sheet (30) comprising a metal foil (1), a polyurethane foam sheet (2) and a base cloth (3).
Are bonded using the adhesiveness of the polyurethane foam sheet (2) without using an adhesive, so that the productivity is high, and a reflective sheet having excellent light irregular reflection and cushioning properties can be manufactured at a low cost. Can be provided.

When a polyurethane foam sheet (2) for the intermediate layer is made of open-cell foam and is provided with a large number of small holes for use in a farm, rainfall can be allowed to enter the soil and rainfall can be reduced. A part of the resin is retained in the polyurethane foam sheet, which contributes to preventing the soil from drying. In addition, if a closed-cell polyurethane foam sheet (2) is used, the heat retention is improved, and a rapid change in the soil temperature or the temperature inside the agricultural house is prevented, and the effect of promoting the growth of agricultural products is exhibited.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view in the thickness direction of an irregularly reflective sheet of the present invention.

FIG. 2 is an explanatory view illustrating a first stage of the manufacturing method.

FIG. 3 is an explanatory view illustrating a second stage of the manufacturing method.

FIG. 4 is an explanatory view schematically showing a heat treatment step.

[Explanation of symbols]

 1. Metal foil 2. 2. Polyurethane foam sheet Base cloth 4. Diffuse reflective sheet Unevenness

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B32B 15/08 B32B 15/08 T 27/12 27/12 27/40 27/40

Claims (3)

(57) [Claims] 1. A polyurethane foam sheet having a metal foil bonded to a surface thereof, a heat-shrinkable base cloth bonded to a back surface of the polyurethane foam sheet, and a heat-shrinkable base fabric on the back surface to form a polyurethane on the front surface metal foil. An irregularly-reflective sheet, wherein irregular wrinkles are formed via a foam sheet. 2. The irregularly reflective sheet according to claim 1, wherein the thickness of the polyurethane foam sheet is 1 to 5 mm. 3. A gas flame by a burner is applied to one surface of the polyurethane foam sheet to melt its surface layer.
A heat-shrinkable base fabric or metal foil is supplied to the melted surface immediately after melting to bond the two together under pressure, and the other surface of the polyurethane foam sheet is exposed to a gas flame by a burner to melt the surface layer. Immediately after the melting, a metal foil or a base cloth is supplied to the melted surface and pressure-bonded, and then the heat-shrinkable base cloth is shrunk by applying a heat treatment to the three-layer composite sheet in an unrestrained state, A method for producing a diffusely reflective sheet, characterized in that a wrinkle-like irregular pattern is formed on a metal foil on the surface via a polyurethane foam sheet by shrinking the base cloth.