Apparatus for radiation-curing of coating on multi-sided object

Abstract

Apparatus for ultra-violet light curing by photopolymerization of radiation free ink or coating material, which is coated on the peripheral surfaces of a multisided rotatable object: each uncured ink coated object is positioned on a rigid or resilient support at the end of a respective mandrel; the mandrels are rotatably journaled to an endless belt, or the like, which moves the mandrels and the objects supported thereon through a radiation oven; each mandrel carries a wheel, which engages a rack that is oriented parallel to the pathway of the mandrels through the oven such that the mandrels and the objects they support are rotated as they move along the path through the oven; a radiation emitting lamp in the oven is in a plane that is spaced from the axes of the objects as they move through the oven and is generally parallel to the path of movement of the objects through the oven; the lamp is oriented obliquely to the direction of extension of the mandrels and the objects as they pass through the oven to cause uniform radiation impingement along the length of each object on its mandrel. A battery of ovens may be provided through which the objects pass successively.

I claim: 
     
       1. Apparatus for curing a solvent-free coating on the peripheral surfaces of an object, comprising: a curing oven having an entrance and an exit and a path therebetween; a radiation lamp supported in said oven and positioned to direct curing radiation across said oven and across said path therein;   at least one mandrel for supporting an object; mandrel moving means connected with said mandrel for moving it to guide the object supported by said mandrel, through said oven along said path therein;   mandrel rotating means connectable with the mandrel and positioned to continuously engage and continuously rotate said mandrel and the object as the object passes through said oven on said path therein; said mandrel rotating means comprising a rack means orientedd generally parallel to said path; and a wheel supported by said mandrel; said rack means being positioned such that said mandrel wheel continuously engages said rack as the object supported by said mandrel passes through said oven.   
     
     
       2. The apparatus for curing a coating of claim 1, wherein said path has a predetermined length for the portion thereof while radiation is impinging upon the object; said rack means has a length at least as long as said path portion. 
     
     
       3. The apparatus for curing a coating of claim 2, wherein said lamp is supported away from said path and is in a plane spaced from the axis of rotation of the object as it moves along said path. 
     
     
       4. The apparatus for curing a coating of claim 3, wherein said lamp is oriented obliquely with respect to said path and the axis of the object so that as the object moves along said path, the radiation from the lamp moves along the axis of the object. 
     
     
       5. The apparatus for curing a coating of claim 1, wherein the object is hollow and includes an opening to receive said mandrel; said mandrel includes a rigid object support shaped and positioned to fit into an opening in the hollow object. 
     
     
       6. The apparatus for curing a coating of claim 1, wherein said object support comprises a plurality of resilient fingers supported on said mandrel and deflectable with respect thereto. 
     
     
       7. The apparatus for curing a coating of claim 1, further comprising a plurality of said mandrels all connected with and movable by said mandrel moving means, thereby to move the objects through said oven in succession. 
     
     
       8. The apparatus for curing a coating of claim 4, wherein the object is hollow and includes an opening to receive said mandrel; said mandrel includes a resilient, outwardly biased object support which is resiliently deflectable to enable said object support to fit into an opening in the object and to be biased outwardly to engage and support the object on said mandrel. 
     
     
       9. Apparatus for curing a solvent free coating on the peripheral surfaces of an object, comprising: a curing oven having an entrance and an exit and a path therebetween; a radiation lamp supported in said oven and positioned to direct curing radiation across said oven and across said path therein; said lamp being elongated along a straight axis;   object moving means connected with said object for moving it to guide the object through said oven along said path therein;   rotating means connectable with the object and positioned to rotate the object as it passes through said oven on said path therein; the axis of rotation of said object being generally peripendicualar to the direction of said path;   said lamp being supported away from said path and being disposed in a plane spaced from and parallel to the axis of rotation of the object as it moves along said path; said lamp axis being oriented obliquely with respect to said path and extending along said path so that as the object moves along said path, the radiation from the lamp moves along the axis of the object.   
     
     
       10. The apparatus for curing a coating of claim 9, wherein said object rotating means comprises a rack means oriented generally parallel to said path; and a wheel supported by said mandrel; said path has a predetermined length for the portion thereof while radiation is impinging upon the object; said rack means has a length at least as long as said path portion; said rack means being positioned such that said mandrel wheel continuously engages said rack as the object supported by said mandrel passes through said oven. 
     
     
       11. The apparatus for curing coating of claim 10, wherein said oven is an enclosed housing with said entrance and said exit being openings thereinto; said rack means being positioned externally of said oven housing; each said mandrel including an object support for supporting an object, which said support is in said housing as said support moves along said path; each said mandrel wheel being exterior of said housing; said housing having a slot parallel to said path for permitting movement of said mandrel along said path.   
     
     
       12. The apparatus for curing a coating of claim 10, wherein said lamp is supported away from said path and in a plane spaced from the axis of rotation of said object as it moves along said path. 
     
     
       13. The apparatus for curing a coating of claim 11, which comprises a plurality of said ovens each having the characteristics of the said oven; said ovens being so positioned that said entrance of one said oven is spaced a distance from said exit of the preceding said oven; said mandrel moving means being so shaped and positioned as to move said mandrels successively through said ovens from their respective said entrances through their respective said exits. .Iadd. 14. Apparatus for curing inks and decorative coatings on containers comprising   a. a conveyor having container rotating means on which decorated containers are mounted for rotation while being carried by the conveyor,   b. means for rotating said container rotating means, and   c. an ultra violet light assembly including a longitudinally extending lamp tube and reflector, said assembly extending at an oblique angle to the path of travel of the conveyor for beaming a band of concentrated ultra violet light on the rotated containers while the containers move past the light assembly, the angle at which the assembly extends relatively to the path of travel of the conveyor being determined by the axial length of the containers such that each container receives bands of ultra violet light in helical pattern progressively from end to end of the container body while it is carried by the conveyor past the assembly. .Iaddend. .Iadd. 15. The apparatus defined by claim 14, in which the containers are externally decorative with ultra violet sensitive inks or coatings. .Iaddend. .Iadd. 16. The apparatus defined by claim 14, in which the conveyor is a peg-chain type conveyor, each peg comprising a pin extending at a right angle to the chain of the conveyor, and a sleeve of yieldable material rotatably mounted on the pin and frictionally engaging the interior of the container body. .Iaddend. .Iadd. 17. The apparatus defined by claim 16, in which the containers have cylindrical bodies closed at one end and open at the other end, and the said pegs enter the containers through said open ends. .Iaddend.