WO2004073894A2

WO2004073894A2 - Ultraviolet radiation curing apparatus

Info

Publication number: WO2004073894A2
Application number: PCT/US2004/004704
Authority: WO
Inventors: Michael J. Keith; Daryl B. Parker
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-02-18
Filing date: 2004-02-18
Publication date: 2004-09-02
Anticipated expiration: 2005-08-18
Also published as: WO2004073894A3

Abstract

A mobile ultraviolet substrate coating curing apparatus (10) includes a manual or self-propelled mobile unit with a scanning or reciprocating light module with a light source such as an ultraviolet lamp in a light box or head (16) so that the light source cures the coating as it scans back and forth, simultaneously with the forward motion of the mobile unit over the substrate, such as floor (12). The reciprocation of the light module cures a greater surface area of the coating in a shorter period of time than with a fixed lamp. The mobile unit may comprise a main body (14) and wheel (18 and 20).

Description

ULTRAVIOLET RADIATION CURING APPARATUS

BACKGROUND OF THE INVENTION

Technical Field

[0001] The present invention relates generally to the curing of substrate coatings using ultraviolet radiation and, more particularly, to an improved method and apparatus for curing substrate coatings.

Background Art

[0002] Ultraviolet curable substrate coatings are particularly well suited for use upon floors since they have the desirable characteristics of abrasion resistance, water and chemical resistance, high gloss and so on, while providing a durable coating that will require little care and upkeep.

[0003] Ultraviolet coatings can be clear, pigmented, conductive, or static dissipative. They can be used to coat a wide variety of surfaces including but not limited to vinyl tile, sheet vinyl, wood, concrete, terrazzo, ceramic tile, grout, and plastic.

[0004] Conventional ultraviolet curing sources use fixed ultraviolet vapor lamps which put out a straight or curved line of light which is mounted to a manual or motorized vehicle and moved across the surface to be cured. Surface coatings, in turn, are commonly applied by any conventional coating means, typically about 0.5 to 5 mils thick, over a large surface area. The applicable coatings will not dry until exposed to high intensity ultraviolet radiation. A conventional ultraviolet lamp is typically mounted on the front of the vehicle and will instantly cure the coating as the vehicle is moved over the coating. [0005] Gaven et al. U.S. Pat. No. 5,667,850 describes a method for curing ultraviolet light-curable coatings, inks or adhesives on heat sensitive substrates, wherein the substrates are coated and then passed under ultraviolet light. It includes reducing the temperatures of the substrates while being passed under the ultraviolet light by providing a shield at a location between the ultraviolet light and the substrates. The shield is substantially infrared light reflective and absorptive to prevent infrared light from reaching the substrates and is also substantially ultraviolet light permeable to permit ultraviolet light to reach the substrates. An ultraviolet light curing device which utilizes the aforesaid shield is also described for curing ultraviolet light curable coatings, printings and adhesives on heat sensitive substrates. [0006] Gaven et al. U.S. Patent No. 6,207,118 discloses a mobile ultraviolet substrate coating curing device which is adapted to cure substrate coatings in inaccessible areas, such as floor corners, walls, overhangs, edges and ceiling, and includes a curved or generally bent ultraviolet vapor lamp source which is coupled with a power efficient mobile curing unit. The curved ultraviolet vapor lamp may be shuttered, either manually or automatically. The carriage unit may be operated at constant speed to provide uniform curing energy. The curved ultraviolet vapor lamp is preferably situated adjacent to the coated surface and is preferably backed by a reflector which enhances the curved ultraviolet vapor lamp emissions so as to more adequately broadcast the emissions toward all bordering expanses of the substrate coating. The mobile curing unit may be further adapted to use battery power, thus permitting absolute mobility.

[0007] Berg et al. U.S. Patent No. 6,096,383 teaches a process for applying a coating to a floor surface and curing that coating after application includes the steps of first spreading a photochemically curable liquid coating in a thickness of from about 0.003 to about 0.006 inches on a floor surface. After the coating has been applied, it is exposed to ultraviolet radiation at a power level of about 40 watts per inch of width of coating being cured and at two different sequentially applied wavelengths. This cures the liquid coating instantly to a durable solid coating. The first applied ultraviolet radiation may have the wavelength of about 365 nm and the second applied ultraviolet radiation may have a wavelength of about 254 nm. The ultraviolet radiation is provided by an array of UV lights on a mobile, self-powered vehicle which moves over the floor coating at a speed in the range of 20 to 40 feet per minute. [0008] Hillenbrand U.S. Patent No. 6,245,392 describes a mobile coating and curing apparatus for applying and curing an ultraviolet or an electron beam curable material. The apparatus includes a housing containing a first compartment containing a coater, a second compartment containing an ultraviolet or electron beam curing energy source, a partition wall between the first and second compartments and a means for moving the housing across a surface to be coated. The apparatus provides a means for coating surfaces which are generally too large to be coated by stationary coating and curing devices. [0009] The foregoing patents reflect the current state of the art of which the present inventor is aware. Reference to, and discussion of, these patents is intended to aid in discharging Applicant's acknowledged duty of candor in disclosing information that may be relevant to the examination of claims to the present invention. However, it is respectfully submitted that none of the above-indicated patents disclose, teach, suggest, show, or otherwise render obvious, either singly or when considered in combination, the invention described and claimed herein.

Disclosure of Invention

[0010] The ultraviolet radiation curing apparatus of the present invention provides a mobile ultraviolet substrate coating curing apparatus. The apparatus includes a manual or self- propelled mobile unit with a scanning or reciprocating light module with a light source such as an ultraviolet lamp, so that the light source cures the coating as it scans back and forth, simultaneously with the forward motion of the mobile unit. The reciprocation of the light module cures a greater surface area of the coating in a shorter period of time than with a fixed lamp.

[0011] The scanning light source can be made to reciprocate using a pneumatic drive system, hydraulics, electric motors using a screw, continuous belt, or shaft, or any other type of mechanical or electrical power. The scanning speed may be varied for particular light sources, coatings, and applications. The range of the reciprocation may be adjusted to achieve a flexible curing width. In addition, the sweeping motion of the scanning light source may permit the use of higher power lamps than would otherwise be usable.

[0012] The light source may be a low, medium, or high pressure mercury arc bulb (which can be doped with various metals to achieve specific wavelengths), a fluorescent bulb, LEDs, non-mercury pulsed arc lamps, solid state curing systems that use no light bulb, or any other appropriate lamp, bulb, or light source.

[0013] The ultraviolet lamp may be shuttered, either manually or automatically. The mobile unit may be operated at constant speed to provide uniform curing energy. The electrical current outlay provided to the ultraviolet lamp may be automatically altered in correlation with the speed of the operation of the mobile unit in order to maintain a constant curing level.

The ultraviolet lamp is preferably situated adjacent to the coated surface and may be backed by a reflector which enhances the ultraviolet lamp emissions so as to more adequately broadcast the emissions toward all bordering expanses of the substrate coating. The present invention mobile curing unit may be further adapted to use battery power, particularly with appropriate light sources such as LEDs, thus permitting greater mobility.

[0014] The inventive curing system may be used to cure ultraviolet coatings of all chemistries including acrylics, epoxies, polyesters, vinyl esters, etc., and both 100% solids and water-based materials. The system may be associated with an edge-curing machine that may be operated from the main unit's power supply, or a separate battery pack.

[0015] It is therefore an object of the present invention to provide a new and improved mobile, power efficient ultraviolet radiation substrate curing device that will cure large areas quickly.

[0016] It is another object of the present invention to provide a new and improved apparatus to achieve such curing functions with exceptional power efficiency.

[0017] A further object or feature of the present invention is a new and improved lamp source and curing equipment configuration which yields maximum ultraviolet energy while at the same time minimizing power input.

[0018] Other novel features which are characteristic of the invention, as to organization and method of operation, together with further objects and advantages thereof will be better understood from the following description considered in connection with the accompanying drawing, in which preferred embodiments of the invention are illustrated by way of example. It is to be expressly understood, however, that the drawing is for illustration and description only and is not intended as a definition of the limits of the invention. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming part of this disclosure. The invention resides not in any one of these features taken alone, but rather in the particular combination of all of its structures for the functions specified.

[0019] There has thus been broadly outlined the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form additional subject matter of the claims appended hereto. Those skilled in the art will appreciate that the conception upon which this disclosure is based readily may be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.

[0020] Further, the purpose of the Abstract is to enable the national patent office(s) and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The Abstract is neither intended to define the invention of this application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way. [0021] Certain terminology and derivations thereof may be used in the following description for convenience in reference only, and will not be limiting. For example, words such as "upward," "downward," "left," and "right" would refer to directions in the drawings to which reference is made unless otherwise stated. Similarly, words such as "inward" and "outward" would refer to directions toward and away from, respectively, the geometric center of a device or area and designated parts thereof. References in the singular tense include the plural, and vice versa, unless otherwise noted.

Brief Description of the Drawings

[0022] The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:

[0023] FIG. 1 is a pictorial view of a curing apparatus of this invention in operation to cure substrate coatings on a floor; and

[0024] FIG. 2 is a bottom plan view of a curing apparatus of this invention.

Best Mode for Carrying Out the Invention

[0025] Referring to Figs. 1 and 2, wherein like reference numerals refer to like components in the various views, Fig. 1 is a pictorial view of a curing apparatus 10 of this invention in operation to cure substrate coatings on a floor 12. Curing apparatus 10 preferably includes a main body 14, which contains the power supply, controls, and transport motor (not illustrated), and the light box or head 16. Drive wheels 18 and swivel wheels 20 support the main body and light box over the floor, in a manner well known in the art. Floor 12 may be vinyl tile, sheet vinyl, wood, concrete, terrazzo, ceramic tile, grout, plastic, or any other composition suitable for ultraviolet curable substrate coatings.

[0026] FIG. 2 is a bottom plan view of a curing apparatus 10 of this invention. Light box 16 preferably includes a track 22 carrying a reciprocating light module 24 with ultraviolet lamp 26. Drive 28 reciprocates the light module back and forth along track 22 at a controllable rate, using a pneumatic drive system, hydraulics, electric motors using a screw, continuous belt, or shaft, or any other type of mechanical or electrical power. In this manner, lamp 26 scans over and cures the substrate coating over an area A equal to the length of the lamp L times the width of the reciprocation W (A=L x W). This wide area of coverage, combined with the forward motion of the mobile unit, enables the light source to cure a greater surface area in a shorter period of time than would be possible with a fixed lamp. [0027] The lamp may be shuttered, either manually or automatically. For instance, when the wheels are not turning and the mobile unit is at rest, the shutter may remain closed. Once movement commences, the shutter will open. In addition, the ultraviolet lamp source preferably warms up in full power when the shutter is open and switches to a lower standby power once the shutter is closed. An emergency shutter position relay-switch may be utilized to prevent having the ultraviolet lamp source reach high power with the shutter closed. [0028] The foregoing disclosure is sufficient to enable one having skill in the art to practice the invention without undue experimentation, and provides the best mode of practicing the invention presently contemplated by the inventor. While there is provided herein a full and complete disclosure of the preferred embodiments of this invention, it is not intended to limit the invention to the exact construction, dimensional relationships, and operation shown and described. Various modifications, alternative constructions, changes and equivalents will readily occur to those skilled in the art and may be employed, as suitable, without departing from the true spirit and scope of the invention. Such changes might involve alternative materials, components, structural arrangements, sizes, shapes, forms, functions,- operational features or the like.

[0029] Accordingly, the proper scope of the present invention should be determined only by the broadest interpretation of the appended claims so as to encompass all such modifications as well as all relationships equivalent to those illustrated in the drawings and described in the specification.

Claims

CLAIMS What is claimed as invention is:

1. A mobile ultraviolet radiation curing apparatus for curing a substrate coating, said apparatus comprising: a body portion; means for supporting said body portion over the substrate; a light module; and means for reciprocating said light module in said body portion and over the substrate to cure the coating.

2. The mobile ultraviolet radiation curing apparatus of claim 1 wherein said means for supporting said body portion over the substrate comprises wheels.

3. The mobile ultraviolet radiation curing apparatus of claim 1 wherein said light module includes a UV lamp.

4. The mobile ultraviolet radiation curing apparatus of claim 1 wherein said light module is carried on a track.

5. The mobile ultraviolet radiation curing apparatus of claim 1 wherein said light module is contained in a light box.

6. The mobile ultraviolet radiation curing apparatus of claim 1 wherein said means for reciprocating said light module comprises a linear track.

7. A method for curing a substrate coating, said method comprising: providing a mobile ultraviolet radiation curing apparatus having a body portion, means for supporting the body portion over the substrate, and a light module; and reciprocating the light module in the body portion and over the substrate to cure the coating.

8. The method for curing a substrate coating of claim 7 further including the step of providing wheels to support the body portion over the substrate.

9. The method for curing a substrate coating of claim 7 further including the step of providing the light module with a UV lamp.

10. The method for curing a substrate coating of claim 7 further including the step of carrying the light module on a track.

11. The method for curing a substrate coating of claim 7 further including the step of housing the light module in a light box.

12. The method for curing a substrate coating of claim 7 further including the step of reciprocating the light module on a linear track.