WO2008016716A2

WO2008016716A2 - A process of making retro-reflective material

Info

Publication number: WO2008016716A2
Application number: PCT/US2007/018265
Authority: WO
Inventors: Tao-Ming Tom King
Original assignee: Tao-Ming Tom King
Priority date: 2006-08-01
Filing date: 2007-08-17
Publication date: 2008-02-07
Also published as: WO2008016716A3

Abstract

A process of making a micro glass beaded retro-reflective material comprising micro glass beads lenses, which is partially embedded in graphic matrixes of binding material. The pre-fixed rotating axes of the micro glass beads lenses lie at varying angles to the general plane of the graphic matrix to achieve uniform visibility in broad range of entrance and observation angles. The gaps between the graphic matrixes [matrices is used in textbooks, matrixes is okay] allow the permeability of the base material to resumes its function (i.e.. breathable of the fabric), maintaining the flexibility (i.e.. softness and rigiditv of the fabric), and the color of the base materials.

Description

TITLE OF THE INVENTION

A process of making retro-reflective material

CROSS-REFERENCE TO RELATED APPLICATIONS References Cited U.S. Patent Documents

3,989,775 November 2, 1976 Jack, et al.

4,763,985 August 16, 1988 Bingham

4,801,193 January 31 , 1989 Martin

5,128,804 July 7, 1992 Lightle, et al.

5,200,262 April 6, 1993 Li

5,344,705 September 6, 1994 Olsen

5,620,613 April 15, 1997 Olsen

5,674,605 October 7, 1997 Marecki

5,738,746 April 14, 1998 Billingsley, et al.

5,900,978 May 4, 1999 Sagar, et al.

6,153,128 November 28, 2000 Lightle, et al.

6,861,134 March 1, 2005 Peters STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT Tao-Ming Tom King

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC.

Not Applicable

BACKGROUND OF THE INVENTION

(1) Field of the Invention

Current U.S. Class: 264/1.1, 1.9, 1.32; 359/519, 537, 538, 540, 546; 396/3; 396/4

Field of Search: 264/1.1 , 1.9, 1.32; 359/519, 537, 538, 540, 546; 396/3; 396/4; 396/3; 396/4

(2) Description of Related Art including disclosed under 37 CFR 1.97 and 1.98 The proposed invention is a micro glass beads reflective fabric. Because of the improved appearance, softness, permeability, and wider observation angles, the application of the glass beads reflective fabric is extended from just an applique on safety garment, to the mainstream of fashion garment industry. The fabric may also be used as photographic background screen for its wide reflective observation angle.

In contrasting with other inventions, the uniqueness and advantages of the proposed invention are listed as below:

The approach of U.S. Pat. No. 3,989,775 discloses beaded retro-reflective material comprising embedding beads in a generally planar plastic matrix and embossing the material to increase observation angles. Due to most of common base material such as cotton fabric, polyester fabric, nylon fabric, paper, PVC (Polyvinyl Chloride), sheeting, and PU (Ployurethane) sheeting are highly elastic that is not suitable for embossing. Therefore, the application of the embossing technique is limited. The proposed invention not only places the micro glass bead lenses in various directions in a permanent manner, see Figure 2 and Figure 3 as attached, but also can be applied to most kind of fabric, paper, leather, and plastic sheeting

The approach of U.S. Pat. No. 4,763,985 discloses a retro-reflective sheet. The retro-reflective construction comprising a monolayer of transparent micro spheres over a base layer of transparent binder material mixed with reflective nacreous pigment flake. The disadvantage of this method is that the binder material in the base layer will always get in between the micro sphere lenses and the reflective nacreous pigment flake, consequently, the reflectivity is reduced. The proposed invention utilizes micro glass beads, metal-coated by vacuum deposition. The aluminum molecular are directly in contact with the glass beads, that the unit reflectivity of each of the micro glass bead lens is more than 200 % brighter than the above approach. Therefore, the same reflectivity may be achieved by using proportionally less micro glass bead lenses that result with softness, permeability and different appearance.

The approach of U.S. Patent 5,128,804, U. S. Patent 6,861,134, U.S. Patent 5,344,705 and U.S. Patent 5,620,613, disclosed retro-reflective transfer sheeting, or reflective transfer sheeting with pores, or reflective transfer sheeting with color layers. The sheeting is a two-sided web of thermoplastic filaments, one side has reflective elements (micro glass bead lenses) partially embedded, and the other side is not. The subject sheet with reflective system on one side may be laminated to a base material like fabric by heat. The disadvantage of using a permeable sheet is that the water and detergent could penetrate the sheet easily reducing the bonding between the micro glass bead lenses and the fabric during washes. When the retro-reflective elements are embedded in the filaments on one side, the pores are mostly blocked by the micro glass bead lenses. The retro-reflective sheeting is not a final product; it needs to be heat laminated to a base material by end users. If the melting point is low, 40 to 60 degree Celsius as suggest in U.S. Patent 5,128,804, the sheeting is difficult to be handled during storage and transportation. When reflective products in transit, the temperature inside trucks or containers can reach far above 60 degree C and activate the bonding process. The bonding strength will be reduced in each cycle of such temperature fluctuation. Also, the bonding agent with low melting temperature will have poor performance in hot or warm water washes. If the melting point is high, as specified 250 degree Celsius as suggest in U.S. Patent 5,128,804, most kind of the synthetic fabric and color pigments of the base fabric will start changing shape or color.

Also, the performance of the final retro-reflective product in as suggest in the above traditional method is heavily depended on the final process of laminating the retro-reflective sheeting to a base material using heat. The heat lamination process is not a part of the above patents. The heat lamination process is often performed by end users who bought the reflective sheeting and laminates it to a garment or fabric by a heat press machine or heating iron. That the retro-reflective sheeting, a highly heat sensitive material, being shipped and processed in uncontrolled environment, and the quality is hard to control. In the proposed invention, the bonding agent is solid, not permeable to improve the wash performance. In the proposed patent the bonding agent is applied directly to the base material before the micro glass bead lenses are applied. And the micro glass bead lenses are embedded to the bonding agent before the bonding agent is fully cured. That the bonding can be generated by chemical reaction which requires less heat. Therefore the process of proposed patent is suitable for broader range of base material..

In U.S. Patent 5,200,262, U.S. Patent 5,738,746, and U.S. Patent 6,153,128, introduced launderable (washable) retro reflective applique and clothing bearing reflective applique, which the reflective systems are fully covered by a binder layer. The retro-reflective appliques were sewn on or heat transfer to the end products, such as a clothing or fabric. The reflective applique comprising a monolayer of retro reflective elements. Under the retro reflective elements is a binder layer. The glass bead lenses are partially embedded in and protruding from the front surface of the binder layer in conjunction with aluminum coated or silver coated optical element. The clear or transparent part of the glass beads, all face the direction opposite of the binder layer. In the proposed invention, there is no binder layer. Instead, the binder is a separated graphic matrix that is placed on the fabric or clothing directly. The micro glass bead lenses are placed on the binder matrix facing various directions. The advantage of the proposed patent is that the end product is lighter, softer, permeable, and has graphic appearance. The reflective system is feasible to cover entire garment, instead of an applique to cover a part of the garment. Also, in the proposed patent, the binder matrix may cover a portion of the base material, that the color of the base material will be visible so that the reflective system has colored appearance.

A similar approach in U.S. Patent 5,900,978 is retro reflective materials by printing ink method. In this method, metal-coated micro glass beads are mixed in a binder of transparent adhesive, and then printed, or painted by brushes, or scraped to the base material in full coverage, or partial coverage. Because the micro glass bead lenses are mixed in the binder adhesive, a liquid carrier, the binder material tends to cover the clear part of micro glass bead lenses. Due to the binder material coating adds to the shape of the micro glass beads lens, and have a different density than pure solid glass, the retro-reflective effectiveness of the micro glass bead lenses is reduced. See Figure 5 as attached. The proposed invention has all the micro glass bead lenses embedded partially on the surface of the binder adhesive, please see figure 3, so that the reflectivity is improved significantly. The proposed invention can make reflective materials with retro-reflectivity over 200% more than retro reflective materials by printing ink method. In U.S. Patent 6,859,941 and U.S. Patent 6,974,610, which described two graphic transfer systems that can be applied to high visibility safety apparels. The reflective system in these two patents uses a heat transfer system with a portion of stripe segments removed from a fully covered retro-reflective transfer sheet. The reflective system remains on the apparel are substantially continuous for the length of the stripe. The stripe segments are formed of retro-reflective material. The disadvantage of the above method is that the removing of stripe segment process is time consuming and with high defect rate. Using this method, the detail of the graphic pattern is limited by the size of the stripe to be removed. Also, to make the final product of reflective fabric or garment, the heat transfer process is performed by the end user and is not a part of the above patents. The final process of the retro- reflective transfer graphic system is a highly sensitive to heat, pressure and timing that the quality of the final product is hard to control. In the proposed invention, the retro-reflective segment may be any graphic pattern, and not limited to stripe patterns. Also, the reflective system does not require being heat transferred. The graphic pattern in the can be isolated or continuous graphic patterns which does not need peeling off or removing stripes from the solid reflective sheeting. The gap between each of the graphic pattern can be 0.5mm and up allowing a much more detailed and complicated graphic pattern to be achieved on base material. When the proposed retro-reflective graphic matrix designed to cover proper portion of the fabric, the reflectivity of the proposed invention can meet or exceed that required by the ANSI/ISEA standard (see Reference 1) being addressed for the safety garment. BRIEF SUMMARY OF THE INVENTION:

The traditional retro reflective fabric are generally used as applique, having been sewn on or transferred to a part of safety garment, to increase the visibility in front of sources of light (such as from a headlight of a car), or to comply with the criteria of safety standard such as ANSI/ISEA standard as shown in Reference 1. The proposed invention has a unique process by applying the retro-reflective system directly to the base fabric, or the body of a garment. Also, the retro-reflective system is in a graphic form. The final product is lighter, permeable and has a different visual appearance. When the area of coverage of the graphic shape is over 80%, the retro reflective fabric manufactured by the proposed patent is able to meet with or exceed ANSI national safety standards. The graphic image on the proposed retro reflective fabric is outlined by repeated array of small graphic shapes. The graphic shapes will include dot, square, cross, alphabets, number, and lines. The size of each graphic shape can be in between 1 mm to 5 mm width. The space between the graphic shapes can be from 0.5 mm and up. Due to the edge of each of the graphic shapes are curved in, see Figure 2 as attached, the micro glass bead lenses are forced facing different directions, which increased the visibility in wider observation angle. The micro glass bead lenses may be sprinkled to the graphic binder matrix, see Figure 3 as attached. The lenses are facing a variety of directions that further enhanced the visibility in wide observation angle. BREIF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In this documents, nine (9) figures and one (1) reference table have been included to illustrate the proposed invention.

Figure 1 is a cross-section view of the retro-reflective material, and the definitions of the entrance angle and observation angle of the light beam.

Figure 2 is an enlarged cross-section view of binder material with micro glass bead lenses partially embedded. The curve of the binder material is forcing the micro glass bead lenses facing different directions.

Figure 3 is a cross-section view of the retro-reflective material when the micro glass bead lenses are applied to the binder matrix in plurality of individual lenses, that the lenses are facing different directions.

Figure 4 is a cross-section view of traditional retro-reflective material that all micro glass bead lenses are facing the same direction.

Figure 5 is a cross-section view of traditional retro-reflective material, ink method, where the micro glass bead lenses are buried in the bonding material.

Figure 6 is an example of the proposed material that can use in a traditional safety vest and has a different appearance.

Figure 7 shows the proposed material applied to fashion garment.

Figure 8 is the enlarged view of combining two different designs of graphic matrix to outline a graphic image.

Figure 9 shows different graphic shapes to form different graphic matrices. Reference 1 is the photometric performance requirements set by ANSI/ISEA 207-2004, which is an industry standard commonly referred as Section 8.1 Table 5.

DETAIL DESCRIPTION OF THE INVENTION

The proposed invention is a process for manufacturing retro-reflective material using micro glass bead lenses retro reflective system on base material include fabric, paper, leather and plastic sheeting.

(1) Retro-reflective system

The improvements over the traditional method include the retro-reflective effectiveness covering wider entrance and observation angle given a plane normal to surface of the base material; a binder matrix containing graphic shapes properly spaced according to the purpose of various final usages, and a base stratum of material of which could be broader range of fabric, paper, leather, or plastic sheeting. The term of "retro-reflective" used in this specification is defined as the majority of a light beam incident onto the reflective surface of the invention is directed back to the light source.

(2) Metalized Beads and Micro Glass Bead Lenses

There are plurality of micro glass bead lenses embedded partially in the binder material in the proposed invention of retro-reflective system. A micro glass bead lens is a glass sphere shape and having a refractive index in the range from 1.9 to 2.0. The size of the glass bead lens is from 30 micron to 80 micron in diameter. The beads are coated hemi-spherically by vacuum depositing aluminum vapor. The other hemi-sphere is kept clear and transparent. The micro glass bead lenses used in the process may be obtained by sprinkling a mono layer of clear and transparent micro glass beads to a paper or plastic sheeting, and then coating the sheeting with a thin aluminum layer on the glass beads side. The semi product of above is defined as "metalized bead sheeting" in this specification. The micro glass beads in the "metalized bead sheeting" may be scraped down by rubbing or washing. The beads collected in the above process have been coated hemi-spherically by aluminum is defined as "micro glass bead lens" in this specification.

(3) Bonding Process

The binding material is an adhesive formula in adequate viscosity with proper cross link so that it may create adequate bonding to both the base material and the micro glass bead lenses, yet will not sink nor cover with the micro glass bead lenses when beads are applied.

(4) Graphic Matrix

The process in the proposed invention, start with placing the binding material to the base material in arrays of graphic shape. The graphic shape sizes are from 1 mm width of length and up. The graphic shape, as shown in Figure 9, could be straight line, curve, isolated shape, repetitive, or non-repetitive. The gap between each graphic shape is from 0.5 mm and up. The array of the above graphic shape is defined "graphic matrix" in this specification. The total percentage of the binder coverage or graphic matrix coverage can be from 1% and up depending on the usage of the final products. The "micro glass bead lenses" or "metalized bead sheeting" are then applied to the binder material before the binder material is cured. (5) Application to Various Final Products

The product manufactured by the process in the proposed patent can be applied to the following fields: applique for safety garment, fabric for safety garment, fabric for fashion garment, fabric for rainwear and chromatic screen.

As applique, the retro-reflective fabric manufactured by the process of the proposed patent can be slit into stripes and sewn to the safety garment so that the garment can meet the ANSI/ISEA standard, see Reference 1. While the base material or a fabric been coated with the binder in full coverage, the above process can produce a solid reflective fabric with retro-reflective index close to 600 cd/(lx-m²), much higher than what required in the ANSI/ISEA standard 330 cd/(lx- m²). That when the "graphic matrix" has a coverage of total area of proportionally less than full coverage, the applique as part of the safety garment will still meet the ANSI/ISEA standard.

The retro-reflective fabric manufactured by the process of the proposed patent can also be used as the body of safety garment. When the proposed technique applied directly to a fluorescent fabric, the fabric can be made into garment and meet with the ANSI standard. The "graphic matrix" can be designed to cover sufficient area on the garment to meet with the same standard. For an ANSI/ISEA standard, Class 2 garment, which requires reflective area to be 203 square inches, about 30-40% coverage area of a safety vest. The "graphic matrix" can be designed to cover 30-40% of the fabric surface to meet with the standard. (6) More Options for Designing

Because the retro-reflective fabric manufactured in the propose patent has graphic appearance and comfortable effect listed above, the fabric has been used in fashion industry as a garment, which covers the whole or part of the body as formal dresses. As an option, for producing retro-reflective garments for fashion purpose, the "micro glass bead lenses" can be dyed by transparent paint before sprinkled to the bonding "graphic matrix". The "graphic matrix" together with other color prints or the color of the base fabric can present an effect of multi-color graphs, letters, or logos on the fabric. Garment of the retro-reflective effect has offered the fashion designer an alternative choice of making attractive garment, also improving the safety of traveling after dark.

(7) Special Use for Chromatic Screen

The retro-reflective fabric manufactured by the process in the proposed patent is suitable for making chromatic screen for photographing background screens. The background screen or wall material used in the traditional photographic studio is general painted in blue or green color. The blue or green background is used in traditional studios for replacing the background scenery as part of technique in editing photo pictures, videos, or movies. The background color needs to have a bright background lighting to reveal, and the foreground lighting has to be equal or stronger than the background lighting to balance the intensity of the picture quality. Due to the combination of strong retro-reflective effect with wide entrance and observation angle effect of the proposed patent, the retro-reflective fabric in the proposed patent has been designed to meet the criteria of chromate background screens.

The "graphic matrix" in the proposed patent for chromate screen application, could be designed at an optimum gap between each and every graphic shapes and an optimum size of the graphic shape and manufactured by the process suggested by the proposed pattern. When the base material is fully covered by bonding layer instead of in graphic matrix pattern, as long as the sprinkling technique as show in Figure 2 is applied, the product may still able to use as chromate screen purpose as in claim 6. However, this material is less flexible and with smaller entrance and observation angle than that with the graphic matrix.

Claims

CLAIM OR CLAIMS

1. A process of making retro reflective material, which contains plurality of micro glass bead lenses, a binder graphic matrix and a sub stratum. The base sub stratum is defined to be fabric. The binder matrix is a form of adhesive which is applied on the base stratum in graphic matrix form. The reflective micro glass bead lenses are applied on the surface of binder matrix and partially embedded in the binder matrix. The micro glass bead lenses are transparent glass beads with refractive index from 1.9 to 2.0, size between 30 micron to 80 micron in diameter, with a thin layer of aluminum coated on semi sphere surface.

2. A process according to claim 1 , in which the base sub stratum is leather.

3. A process according to claim 1 , in which the base sub stratum is plastic sheeting.

4. A process according to claim 1, in which the graphic matrix has coverage from 1 % to 99% over the base sub stratus.

5. A process according to claim 1, in which the micro glass bead lenses are fully coated by transparent color pigments.

6. A process according to claim 1 , in which the binding matrix has a full coverage over the base sub stratum, and in which the micro glass bead lenses, which applied on the binder matrix is plurality of individual lenses.