Synthetic fabric with improved optical transparency

Abstract

A fabric formed by weaving monofilaments (2) of synthetic material and having two opposing metallized surfaces, at least one of said surfaces having at least one color (5) that determines the level of transparency. Compared to conventional fabrics for forming transparent panels for the architectural sector, the fabric according to the invention has the advantage that the level of transparency to light can be controlled depending on the color applied to the metallized surface of the fabric.

Description

Technical Field

[0001] The present invention relates to a synthetic material fabric with improved optical transparency effect.

[0002] The field of the present invention is, for example, the field of synthetic material fabrics used in the manufacture of laminated glass and plastic panels with a light-shielding effect in the construction field.

Background Art

[0003] Currently, laminated glass and the like, which are particularly used for building facades, are known. This can reflect light on the outside of the building and at the same time be transparent on the inside of the facade. This result can be obtained, for example, by using a film for glass or by incorporating a fabric metallized on only one side into glass or transparent plastic. The metallized surface incorporated between two sheets of glass or transparent plastic faces the outside of the building, reflects light, and provides a shielding and privacy effect to outside observers, while the non-metallized surface is recognized as transparent to observers inside the building.

[0004] The main drawback of the above-mentioned conventional panels is that the level of transparency of the fabric at which the desired privacy effect is achieved is determined not only by the free surface area of the fabric or the ratio of the openings of the mesh forming the fabric, but also by the metal coating applied to form the metallized surface of the synthetic material fabric. For this reason, conventional panels are limited to reproducing the classical "one-way mirror" effect, which is closely related to not applying a metal coating to one side of the fabric.

Summary of the Invention

Means for Solving the Problems

[0005] The main objective of the present invention is to provide a fabric formed from a synthetic material that can adjust the privacy or transparency effect to light, which is perceived as different gradients on both sides of the fabric.

[0006] This objective and other objectives are achieved by the fabrics and methods of claims 1 and 10, respectively. Preferred embodiments of the present invention are provided by the remaining claims.

[0007] In relation to conventional fabrics used to manufacture transparent panels in the architectural field, the fabric of the present invention offers the advantage of enabling control over the perceived transparency effect based on the color applied to one or both of the metallized surfaces of the fabric.

[0008] A further advantage of the present invention lies in the possibility of generating a variable and adjustable optical transparency effect on the same metallized surface as the surface itself. [Brief explanation of the drawing]

[0009] These and other purposes, advantages, and features are derived from the following description of some preferred embodiments of the fabric of the present invention illustrated in the accompanying drawings, as non-limiting examples.

[0010] [Figure 1] This is a cross-sectional view of a first embodiment of the fabric of the present invention, in which both sides are metallized, and a color coating is applied to only one of these metallized surfaces. [Figure 2] Figure 1 is a cross-sectional view showing details of the filaments used in manufacturing the fabric. [Figure 3] This is a cross-sectional view of another embodiment of the fabric of the present invention, in which a color layer is applied to both metallized surfaces of the fabric. [Figure 4] Figure 3 is a cross-sectional view showing the details of the fabric filaments. [Figure 5]An example of the fabric of the present invention is shown in a front view, in which a color gradient that adjusts the transparency effect of the same surface is printed on a metallized surface. [Figure 6] Figure 3 is a cross-sectional view showing an example of a panel obtained using the fabric. [Modes for carrying out the invention]

[0011] In Figure 1, the fabric of the present invention, shown as 1 in its entirety, consists of a fabric 4 made of a sheet material formed by weaving together filaments 2, preferably monofilaments of a synthetic material such as polyester. The mesh formed by weaving the filaments is calibrated to form a precision fabric with uniform openings. Preferably, the openings of the mesh cover 15 to 80% of the surface of the fabric 4.

[0012] According to the present invention, the surfaces of both opposing sides of the fabric sheet are metallized by coating them with a layer 3 of a metal such as aluminum or copper. The metallization process can be carried out under vacuum by galvanic processes such as electrodeposition, sputtering, or vapor deposition, as described in US2015 / 0345074A1, for example.

[0013] According to the present invention, the color layer 5 is applied to at least a portion of the metallized outer surface 3 of the monofilament 2 (and therefore the fabric 4 formed by them), and a translucent acrylic ink having UV crosslinking is printed onto the same surface by digital printing or sublimation, and then fixed by passing under a UV lamp.

[0014] Suitable examples of inks in the present invention include, for example, inks from Agfa Graphics NV (Belgium), such as ANAPURNA 1500 RTR CYAN INK, ANAPURNA 1500 RTR BLACK INK, ANAPURNA 1500 RTR YELLOW INK, ANAPURNA 1500 RTR MAGENTA INK, and ANAPURNA 1500 RTR CYAN INK.

[0015] The presence of this color layer 5 results in the perceived transparency on the metallized surface 3 of the fabric 4, which depends on the brightness percentage of the selected hue. In fact, the reflected light energy of the metallized surface 3 is greater when the color selected to form the color layer 5 has a high brightness percentage (by brightness, which is one of the three color characteristics described in "A Color Nation: An Illustrated System Defining All Colors and Their Relations" 1941 by AH Munsell 2004-10-15), and less when the brightness percentage is low.

[0016] Furthermore, considering chromatic colors and separating them into pure color families, using yellow and green, the perceived occlusion properties of the fabric are greater than those of red or blue at the same lightness. This occlusion effect is directly proportional to the overall average reflectance in the measured visible light range (380-780 nm).

[0017] Accordingly, according to the present invention, the natural reflection of light on the metallized surface 3 of the fabric 4 is modified, to a greater or lesser extent, by the selection of colors printed on the metallized surface. In that part, other metallized surfaces of the fabric that are not treated with color make the color applied to the opposite side brighter thanks to the reflective ability of the uncolored metallized surfaces.

[0018] In the variant shown in FIGS. 3 and 4, the color layer 5 is applied to the entire metallized surface of the monofilament 2. In this way, both metallized surfaces of the fabric 4 have the color coating 5. In this embodiment, with the help of the color, it is possible to give the fabric two opposing surfaces with an adjustable transparency effect.

[0019] In the embodiment of the invention shown in FIG. 5, on one or both of the metallized surfaces 3 of the fabric 4, a color layer 5 having a color tone distributed in color bands 5a, 5b, 5c, 5d, for example, on the metallized surface, is applied. The color can be applied in the form of spot colors, gradients, or in the form of decorative or fanciful motifs such as patterns.

[0020] In this way, on the same metallized surface of the fabric of the invention, depending on the different color tones of the color layer 5 applied on this surface, it is possible to obtain different gradients of optical transparency. This result is particularly advantageous when different levels of privacy are desired on the same shielding surface.

[0021] As shown in FIG. 6, using the fabric of the invention, it is possible to obtain a panel incorporating the same fabric in a sandwich structure completed by two sheets 6 of glass or transparent plastic. In the case of glass sheets, two layers 7 of a polymer sealant are also used to hold them together.

[0022] The fabric sheet according to the invention can be used as a stretch panel or partition, or incorporated inside two glass or plastic sheets for use in interior design. In the glass field, gradients are mainly formed using conventional ceramic frit, which always has color limitations and does not allow for a flexible customization service. More rarely, digital printing on a metallized fabric using EVA (a very fragile and expensive polymer interlayer) is used, and then incorporated into the glass, representing an interesting alternative from an industrial, functional, and aesthetic point of view.

Example

[0023] The present invention will be described by referring to the following examples given solely for purposes of non-limiting illustration of the present invention.

[0024] Example 1 : When one side of the fabric is color-printed and the other side is not color-printed In this example, a polyester monofilament fabric with a diameter of 145 μm, a sheet thickness of 255 μm, and a free surface area of the fabric of 44% was prepared. Both surfaces of this sheet were metallized with aluminum by a vapor deposition process (the process described in Patent EP2462274B1), and three samples printed with ink on only one side were prepared. In particular, achromatic colors distinguished from each other by different lightness ratios in the original color recipe were printed. Using a Color i7 model spectrophotometer from X-Rite Incorporated, the lightness or light quantity L value in the finished product, which is a combination of a translucent ink and a metallized surface, was measured again. Using the same spectrophotometer equipped with a plane diffraction grating that operates only in the wavelength range of the visible region (380 nm to 780 nm), the spectral reflectance of light on the surface of the metallized fabric coated with color was measured. The measuring instrument was in transmission / reflection mode (diffuse light with a geometry D8° - spectral measurement angle of 8°), and the light source used was a PULS XEN LAMP incandescent lamp from X-Rite. The computer tool Photoshop (registered trademark) was used to produce the printed colors, and the LAB or CIELAB or CIE LAB 1976 color space designed by the CIE (International Commission on Illumination: an international organization regarding light, illumination, color, and color space) was selected, where L indicates lightness, and A and B are color dimensions opposing the color, that is, A (red - green) and B (yellow - blue). In this specific case, only the value of L (ciel*) was considered, and the values of A and B remained unchanged.

[0025] To demonstrate how the lightness ratio of the colors affects the average reflectance of the fabric of the present invention, black (ANAPURNA 1500 RTR BLACK INK) with L=100 ciel* and medium gray with L=50 ciel* were printed, and as an extreme reference, very light gray with L=90 ciel* was used, where the gray was obtained by printing a smaller amount of black ink.

[0026] The results are shown in Table 1 below. The "Theoretical L Print File" represents the brightness values ​​entered into the print file according to the LAB color space. "L measured on fabric" represents the lightness value measured using an X-Rite Color i7 spectrophotometer on a metallized fabric printed with translucent ink using a color recipe that includes a reference theoretical L.

[0027] On the other hand, "Measured Reflectance (%)" represents the total reflectance in the visible range (380~780nm) measured using an X-Rite Color i7 spectrophotometer in transmission / reflection mode with a geometry D:8°, where D is the illumination caused by diffuse light, 8° is the spectral measurement angle, and the light source used is an X-Rite PULS XENO LAMP incandescent lamp.

[0028] Because it is achromatic, the coordinates of A and B are always 0, and that is why they are not included in the table.

[0029] [Table 1]

[0030] The results showed that the reflectivity of the metallized fabric was influenced by the amount of lightness included in the color recipe of the print file, ranging from a minimum of 26.16% to a maximum of 58.903% in the samples examined.

[0031] Example 2 When applying color to both sides of the fabric In this example, a polyester monofilament fabric with a thickness of 255 μm, a free surface area of ​​44%, and a diameter of 145 μm was prepared. Three samples were prepared by metallizing both sides of this sheet with aluminum by vapor deposition, as in Example 1, and then color printing on both sides. In particular, achromatic ink was used as in Example 1, but this time, to show how one side affects the other, the opposite side printed with red chromatic ink (ANAPURNA 1500 RTR MAGENTA INK) was measured. The apparatus and method were the same as in Example 1.

[0032] The results are shown in Table 2 below. [Table 2]

[0033] The results showed that the reflectivity of one surface is influenced by the reflectivity of the other surface, and this is determined by the brightness of the printed color.

[0034] Example 3 : When applying color to one side of the fabric and not applying color printing to the other side. In this example, a polyester monofilament fabric with a diameter of 145 μm, a sheet thickness of 255 μm, and a free surface area of ​​44% was prepared. Both sides of this sheet were metallized with aluminum by vapor deposition, as in Example 1, and four samples were prepared with color printing on only one side of the fabric. In particular, to verify that yellow and green reflect more light than red and green at the same light intensity L using the LAB model, theoretical colors were created using the base chromatic inks ANAPURNA 1500 RTR CYAN INK, ANAPURNA 1500 RTR BLACK INK, ANAPURNA 1500 RTR YELLOW INK, ANAPURNA 1500 RTR MAGENTA INK, and ANAPURNA 1500 RTR CYAN INK: yellow and blue with values ​​opposite to B, and blue and red with values ​​opposite to A. The finished products, which combine translucent ink and a metal surface, were measured again using an X-Rite Color i7 spectrophotometer to determine the L value. The spectral reflectance of light on the surface of the color-coated metallized fabric was measured using a spectrophotometer equipped with a planar diffraction grating that operates only in the visible range (380 nm to 780 nm), the same as that used in Example 1.

[0035] The results are shown in Table 3 below. "A print file" represents the numerical value of A entered into the print file according to the LAB color space in order to create a color recipe. The "B print file" represents the B value entered into the print file according to the LAB color space in order to create a color recipe. "Measured reflectance" represents the total reflectance in the visible range (380-780 nm) measured using an X-Rite spectrophotometer in the reflectance mode of a D-8° geometry. The value of L does not change with the value of 60ciel*, so it is not included in the table. Only the coordinates of A and B change.

[0036] [Table 3]

[0037] As a result, the surface of a metallized fabric printed with colors having equivalent brightness and opposite color dimensions according to the present invention appears to reflect slightly more light and therefore more opaque when the colors printed on the surface fall into the yellow and green categories. Similar results can be obtained with colors applied in various ways and with different shades.

Claims

1. A fabric formed from a sheet material woven with filaments, A fabric characterized in that the surfaces of both opposing sides of the sheet material are metallized, and one side of the metallized surface has at least one color (5) made of a translucent ink for adjusting the effect of transparency of the fabric to light, or both sides of the metallized surface have colors (5) made of translucent ink for adjusting the effect of transparency of the fabric to light, and the colors (5) on both sides are different.

2. 2. The fabric according to claim 1, characterized in that said semi-transparent ink is an acrylic ink with UV crosslinking, said at least one color (5) giving said at least one metallized surface a transparency gradient that is a function of the same color (5).

3. 3. Fabric according to claim 1 or 2, characterized in that said at least one colour (5) is a light colour suitable for reducing the lightness ratio of said at least one metallised surface.

4. 3. A fabric according to claim 1 or 2, characterized in that said at least one colour (5) is a dark colour adapted to increase the lightness percentage of said at least one metallised surface.

5. 3. Fabric according to claim 1 or 2, characterized in that both sides of the metallized surface have at least one color (5).

6. 3. Fabric according to claim 1 or 2, characterized in that said at least one metallized surface has at least one color (5) with different shades.

7. 7. The fabric of claim 6, wherein said color tone is distributed on both metallized surfaces of said sheet material.

8. 3. A fabric according to claim 1 or 2, characterized in that the filaments are monofilaments (2) and the fabric is a fabric with controlled mesh openings.

9. A panel of this type comprising at least two sheets of transparent material between which is held one or more fabrics according to any one of claims 1 to 8.

10. 1. A method for controlling and adjusting the light transparency effect of a synthetic fabric having a metal coating on both opposing sides, comprising: applying at least one color (5) consisting of a semi-transparent ink to at least one of said metallized surfaces, thereby giving said at least one metallized surface a transparency to light as a function of said at least one color (5); A method according to claim 1, characterised in that when both sides of said metallised surface have at least one colour (5), the colours of both sides are different colours.

11. 11. A method according to claim 10, characterized in that on at least one of said metallized surfaces a colour (5) is applied having a different hue.

12. 11. The method of claim 10, wherein the semi-opaque ink is an acrylic ink with UV light crosslinking.

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