JPS641306B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Background of the Invention The present invention relates to a laminate of light-transmitting synthetic resin having two cover plates extending parallel to each other and a plurality of webs arranged at right angles to these and extending parallel to each other. Regarding products.

Such known laminates are combined with glass to form composite materials and are used, for example, as greenhouse coverings. As a result of their special cross-section, these laminates have relatively high ultimate stress values despite their small wall thicknesses and can be efficiently produced by extrusion methods.

DISCLOSURE OF THE INVENTION It is an object of the present invention to provide a laminate of the type described above which exhibits high light dispersion while retaining the known high ultimate stress values and optical transparency.

According to the invention, this object is achieved in that at least one cover plate of the light-transparent plastic laminate has a structured surface.

In this way, relatively high light dispersion properties can be achieved while maintaining particularly high compressive and bending strengths, thus creating new possibilities for using laminates. Since the contours of objects behind the laminate cannot be discerned, this plate is particularly suitable for use in showers, advertising boards, lighting fixtures, etc. It is particularly advantageous for the plates to have high ultimate stress values despite their very low thickness. Experience has shown that even with structured surfaces very high light transmissions of 70-80% can be achieved, depending on the type of radiation source.

In a preferred embodiment of the invention, the structured surface is provided on the inside of the cover plate adjacent to the web. As a result of this arrangement, the laminate can be easily cleaned, since it is easier to clean the smooth surfaces located on the outside. The advantages of light dispersion described above are maintained without particular limitations.

According to another advantageous embodiment of the invention, the structured side surface of the cover plate is formed by a zigzag-shaped surface. As a result, a particularly strong light dispersion can be achieved, and the relatively bright and dark stripes are dispersed relatively sharply, so that an impression similar to a rectangular grid is formed. Since the incident light is scattered over a large angular range in a large number of directions and the incident beam is therefore also significantly weakened, a shadow cast in the primary beam is visible. A wide band of light is formed on both sides of the projected shadow.

According to a further embodiment of the invention, the total thickness of the cover plate with the structured surface is approximately 0.5 to 1 mm.
In the range of Equivalent to a cover plate.

In a further embodiment of the laminate according to the invention, the structured surface of the cover plate is formed by a corrugated surface. As a result, the grid effect formed by the bright and dark stripes appears to be smoother.

Finally, in a further preferred embodiment of the invention, the texture of the structured surface is irregular. This results in random scattering of the incident light, so that the contours of objects covered by the laminate appear completely distorted and cannot be identified.

Specific Embodiments of the Invention The present invention will be described in detail with reference to embodiments shown in the accompanying drawings.

The laminate 1 shown in FIG. 1 is composed of two mutually extending parallel cover plates 2, 3 and a number of likewise parallel extending webs 4. The laminate 1 shown in FIG. These continuously formed webs 4 are orthogonal to the two cover plates 2, 3, and can be integrally formed with the cover plates 2, 3 by extrusion. The surfaces of the top cover plate 2 are formed to be smooth and flat on both sides, and the bottom cover plate 3 is formed with a structured surface 5 on the inside facing the web 4. The structured surface 5 has a zigzag cross-section and has ribs extending along the length of the web. The thickness d of the bottom cover plate 3 is approximately 0.5~
It is in the range of 1mm.

Tests were conducted to measure the light transmittance and compare it to known laminates, both of which had smooth cover plates. As usual, the light transmittance T is given by the following equation.

T=J:Jo×100% where Jo is the incident light intensity and light amount, and J
are the transmitted light intensity and light amount. It has been found that the light transmission of the laminate 1 formed according to the invention is at most 10% lower than that of the known laminate. A so-called spectro test was conducted to investigate in the laboratory the accelerated exposure effect that occurs on synthetic resin parts due to exposure to sunlight. In this test, the radiation of the xenon high-pressure burner was adjusted to equal natural conditions with two IR filters. The light was scattered by a disc of frosted glass. The laminate of the invention was placed at a distance of 10 cm from the glass disc and a precision pyranometer was placed behind the sample. A light transmittance of 75.2% was measured in this spectrotest.

To demonstrate the effect of making objects behind the new laminate less recognizable, a rectangular diaphragm was inserted into a projector instead of a diaslide and projected onto a screen. The laminate sample was inserted into the optical path at a distance of 1.5 m from the projection screen, and the sample image appearing on the screen was photographed.
It was confirmed that the internally structured laminate creates a projected shadow and at the same time forms a wide band of light on both sides of the projected shadow. This is explained because a significant portion of the incident light is scattered in multiple directions and at large angles. The incident light beam is also significantly weakened and a projection shadow can be seen in the primary beam.

The laminate 6 shown in FIG. 2 comprises an upper cover plate 7 with smooth surfaces on both sides, and a lower cover plate 9 extending parallel thereto has a structured corrugated surface 10 on its inside. The two cover plates 7, 9 are connected together by mutually parallel webs 11.

The embodiment of the laminate 12 shown in FIG.
6 is formed.

Finally, the laminate 17 shown in FIG. 4 has structured surfaces 20, 21 on both the insides of the cover plates 18, 19.
has. The upper structured surface is shaped to be wavy, while the lower structured surface is shaped to be irregularly textured.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a laminate according to the invention, and FIGS. 2, 3 and 4 are side views showing different embodiments of the laminate according to the invention. 1, 6, 12, 17...Laminated product, 2, 3, 7,
9, 13, 14, 18, 19... Cover plate, 4, 11, 15... Web, 5, 10, 1
6, 20, 21...Structured surface.

Claims (1)

[Claims] 1. In a light-transmitting synthetic resin laminate having two mutually parallel cover plates and mutually parallel webs extending perpendicularly thereto, at least one cover plate has a surface with a light scattering structure on the inside thereof. A laminate product characterized by having. 2. The laminate product according to claim 1, wherein the side surface of the light scattering structure of the cover plate is formed by a zigzag-shaped surface in cross section. 3. The laminate product according to claim 1, wherein the cover plate having the surface of the light scattering structure has a total thickness of 0.5 to 1 mm. 4. The laminate product according to any one of claims 1 to 3, wherein the surface of the light scattering structure of the cover plate is formed as a surface with a wavy cross section. 5. Claims 1 to 5, wherein the surface of the light scattering structure of the cover plate is formed in an irregularly uneven shape.
The laminate product according to any one of Item 4.