APPARATUS AND PROCESS FOR PRINTING BAR CODES

Abstract: Apparatus and process for printing bar code arrays on a continuous web of absorbent material with ultraviolet-curable ink in sequential manner and drying the printed area with ultraviolet radiation immediately after printing and then accommodating rewinding or refolding of the print web.

Description: APPARATUS AND PROCESS FOR PRINTING BAR CODES Technical Field The present invention relates to printing of bar codes. More particularly, the present invention relates to an apparatus and process for sequential printing of solid areas or lines of different widths on continuous webs of absorbent material, such as paper, which may be in roll form or in collated pack, folded form. Background Art The use of bar codes for identifying data and/or information is increasing in volume and in various applications throughout the media industry. Printing of the bar codes can be accomplished using standard letterpress inks which are formulated to remain "open" (undried or not set) in the ink train and to be machine processed with minimum, if any, solvents or like drying agents. The result is that such inks remain "open" after being applied to paper or like record media. In the printing of bar codes, without voids in the printed areas, it has been found necessary to carry and to use excess ink for the printing operation. Disclosure of Invention It is an object of the invention to provide an apparatus and process for printing high quality bar codes on a continuous web of absorbent material in which the above disadvantage is alleviated. Thus, according to the invention, there is provided an apparatus for printing bar codes on a continuous web of absorbent material, characterized by printing means including a supply of ultraviolet- curable ink; transport means for continuously moving said web past said printing means; driving means for operating said printing means for sequentially printing bar code arrays on said web during advancement thereof; and drying means for drying the printed bar code arrays with ultraviolet radiation immediately after the printing operation. According to another aspect of the invention, there is provided a process for printing bar codes on continuous web of absorbent material, characterized by the steps of providing printing means containing a supply of ultraviolet-curable ink, advancing the substrate along a path past the printing means, driving the printing means for sequential printing of bar code arrays on said web during advancement thereof, and drying the printed bar code arrays with ultraviolet radiation immediately after the printing operation. The ultraviolet-curable ink is letterpress black and is especially suitable for use in printing bar codes to ensure complete bar or area printing with minimum voids in the printed format. The use of the ultraviolet radiation drying apparatus provides for rapid drying of the ink to enable rewinding of the continuous form or the repacking or refolding of the forms immediately after printing without extraneous ink offsetting to non-print areas of the form. Brief Description of the Drawings Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a side elevational view in diagrammatic form of a printing apparatus according to the invention for roll media; Fig. 2 is a similar view of another embodiment of the printing apparatus according to the invention for pack or folded media; Fig. 3 is a portion of a continuous web showing a bar code arrangement imprinted by the apparatus of the present invention; Fig. 4 is a representation of a bar code arrangement printed with standard printing ink; Fig. 5 is a representation of a similar bar code arrangement printed with the ultraviolet-curable ink and dried with the ultraviolet drying apparatus employed in the present invention; and Fig. 6 is a side elevational view in diagrammatic form of an arrangement for folding a continuous web into pack form. Best Mode for Carrying Out the Invention Referring now to the drawing. Fig. 1 is a diagrammatic representation of the apparatus of the present invention for printing of bar codes on a continuous record medium. The printing apparatus is generally indicated as 20, and includes a base framework 22 with upstanding members 24 and 26, a top member 28 and a central support member or tower 30. It is, of course, realized that the illustration is diagrammatic in form and a number of details have been omitted for clarity. A suitable motor 32 is provided to drive various elements of the apparatus 20 under the control of suitable control means 33. A continuous web 36 of record media is provided in a supply roll 38 suitably journaled on a shaft 40 and supported on a cradle 41 at the left side of the printing apparatus 20. The web 36 may comprise a recording sheet or layer and a backing sheet which constitute the record media and on which are printed bars of different widths to effect black images with white spaces therebetween. The bar code arrangement of different width, black-printed, spaced bars is well known in the art and is used in many and various applications in the recording industry. A take-up or rewind roll 42 is provided at the right side of the mechanism 20 and is suitably journaled on a shaft 44 supported on a cradle 45. The web 36 is driven along a path from the supply roll 38, upwardly around and past a corner member or roller 46, which may be journaled on a suitably supported shaft 48, and then advanced along a table or platform 50. The web 36 continues along the table 50 and under a printing or numbering wheel assembly 52 suitably journaled on a shaft 54, the assembly 52 including a plurality of print elements 56 positioned on the quadrants thereof. A suitable reservoir 57 of ultraviolet-curable ink is provided to supply the print elements 56 of the numbering wheel assembly 52. Of course, while the reservoir 57 is shown diagrammatically, it is noted that the supply of ink could be contained within the assembly 52. The print elements 56 are spaced across the width and around the periphery of the wheel assembly 52 to print successive bar code arrays onto the web 36 by reason of the rotation of the wheel and rotation of an impression cylinder 58 in the directions indicated by the respective arrows, each bar code array comprising a column of bars of different widths extending across the width of the web 36. The impression cylinder 58 is provided in opposed manner to the wheel housing 52 and is suitably supported by the apparatus 20. The web 36 then passes into and through an ultraviolet radiation dryer 62 which provides for rapid drying of the ultraviolet-curable ink that is used to print and form the bar code arrays in sequential printing manner. The web 36 turns the corner around and past a pull roller or like member 64 which may be journaled on a suitably supported shaft 66. A cooperating pressure or guide roll 68 (also called an over roll) journaled on a shaft 70 is positioned above the pull roller 64 to provide a passageway for the web 36. The supply roll 38 and the rewind roll 42 may be supported for rotation in the cradles 41 and 45, respectively, or by other suitable means. Fig. 2 illustrates another arrangement of apparatus, generally indicated as 80, and utilizing some of the same structure and members of the apparatus, as shown in Fig. 1. The drive motor 32 and apparatus control means 34 may be similar in function, but different in operation from the arrangement of Fig. 1, such control means 34 including a programmable variable length draw in the direction of movement of the web 82. The web 82 in Fig. 2 is formed in a collated pack or folded configuration, as shown in the pack or stack 84 at the left side of the apparatus 80, and unfolds upwardly and around the corner member 46 and along the table 50. The web 82 continues along the table 50 and under an printing or numbering unit 86 which is supported in suitable manner for reciprocating motion in the indicated up-and-down direction. During each printing movement, the reciprocating numbering unit 86 prints a column of bars across the width of the web 82 by means of printing elements 88 spaced across the width of the numbering unit 86, and prints successive columns of bars as such web 82 continues along the table 50. A reservoir or container 89 of ultraviolet-curable ink may be provided in the unit 86 to supply ink to the printing elements 88. A fixed position platen member 90 is provided under the printing elements 88 of the numbering unit 86 and opposed thereto for impacting thereagainst by the printing elements in the printing operation. The web 82 then passes into and through the ultraviolet dryer 62 which provides for rapid drying of the ultraviolet-curable ink that is used to print and form the bar code arrays in sequential printing manner. The web 82 then turns the corner around a sprocketed pin pull roller 64 and the web is then delivered in refolded manner in a receding stacker 92 (movable in the direction as indicated by the arrow) at the right side of the apparatus 80. It is to be noted that while Fig. 1 shows a continuous rolled web 36 and a rotary numbering wheel assembly 52, and Fig. 2 shows an unfolded web 82 and a reciprocating numbering unit 86, the web 36 of Fig. 1 may be used with the reciprocating elements 88. The numbering wheel assembly 52 (Fig. 1) has the advantage of higher speed operation while the reciprocating unit 86 (Fig. 2) prints the bar code arrays at closer spacing in the web advancing direction, as seen from the spacings of the bar codes on the respective webs 36 (Fig. 1) and 82 (Fig. 2). While different width machines are available for the printing operation, the McAdams VC 100 machine readily accommodates a web (36 or 82) width of 40 centimeters. In one arrangement, the reciprocating unit 86 prints ten complete bar code arrays in a web length of 20 centimeters. Of course, it is to be understood and is within the scope of the invention that many other spacings can be accommodated depending upon the bar code size and customer requirements. The wheel assembly 52 (Fig. 1), having a circumference of 56 centimeters and carrying four print elements 56, prints a complete bar code array at 14 centimeters spacings, in one embodiment of the invention. Of course, the spacing of the printed bar code arrays is different for wheels that are provided and spaced for two or three print elements 56 around the circumference. The Fig. 2 arrangement is preferred by reason of the compact spacing and the improved quality of the bar code printing. Fig. 3 shows a portion of the continuous paper web 36 (or 82) used in the present invention and printed with bar codes 94 and 96. A space 98 and a space 100 are provided for printing a company name, a number and certain instructions. The web 36 (or 82) is advanced from left to right along the table 50 for printing of the bar codes 94 and 96 by the rotary wheel assembly 52 (Fig. 1), or by the reciprocating unit 86 (Fig. 2), and for drying of the ultraviolet- curable ink by the ultraviolet lamp processor 62. While Fig. 1 shows the bar codes 96 printed at a spacing on the web 36 corresponding to the four print elements 56 on the wheel, and Fig. 2 shows the bar codes 96 printed at a closer spacing on web 82, any other spacing of the bar codes can be effected and accommodated within the scope of the present invention. Fig. 4 is a representation of a bar code arrangement 102 printed with standard printing ink and showing normal voids 104 in the printed bars due to the non-planar media surface of the substrate. While the presence of such voids 104 may not be critical at lower speed operation, the advent of higher speed reading devices makes precise and well-defined, fully printed, bar codes a necessary requirement and a much needed improvement in the art. Fig. 5 is a representation of a similar bar code arrangement 106 printed with the ultraviolet- curable ink and dried with the ultraviolet radiation processor 62 employed in the present invention and showing the solid bars 108. A definite improvement is seen with bar codes which are printed with ultraviolet-curable ink and with said ink being dried immediately, thereby resulting in minimal voids in the bars. Fig. 6 illustrates an arrangement wherein the web 36 is unwound from the supply roll 38, as shown in Fig. 1, the web is printed with bar codes utilizing either the wheel assembly 52 or the numbering unit 86, the ink is dried by the unit 62, and the web is delivered in fold form onto a receding stacker (as in Fig. 2) at the right side of the printing apparatus. A pin pull sprocket 110 is suitably supported at the right side of the apparatus in similar manner, as shown in Fig. 2, and the web 36 is directed therearound and between two pull rolls 112 and 114 and then through a passageway formed by actuating guides 116 and 118, which may swing in the direction indicated by the arrow. The web 36 is then trained toward and is folded by a pair of cooperating screws 120 and 122 and then placed in a stack 124. The apparatus 80 (Fig. 2) utilized in practicing the method of the present invention may include an imprinting press made by John McAdams and Sons, Inc., Norwalk, Conn. The rotary press of Fig. 1 may be used to print in roll-to-roll arrangement or in roll-to-fold arrangement. A preferred ultraviolet- curable ink is I.P.I. Ultra King, Letterpress Black, No. 86L1133. Another ink of equal quality is Typostar Ultraviolet, black. Art. 32-0-9995, made by Kemisch Fabrik, Aarberg AG, Switzerland. The dryer is UVXL ultraviolet processor with medium pressure mercury vapor lamps, made by RPC Industries, Plainfield, Illinois.

Claims: CLAIMS ; 1. An apparatus for printing bar codes (94, 96) on a continuous web (36, 82) of absorbent material, characterized by printing means (52 56; 86, 88) including a supply of ultraviolet-curable ink; transport means (32; 46, 64, 68) for continuously moving said web (36, 82) past said printing means (52, 56; 86, 88); driving means for operating said printing means (52, 56; 86, 88) for sequentially printing bar code arrays (94, 96) on said web (36, 82) during advancement thereof; and drying means (62) for drying the printed bar code arrays (94, 96) with ultraviolet radiation immediately after the printing operation. 2. An apparatus according to claim 1, characterized in that said printing means (52, 56; 86, 88) includes a rotary printing wheel (52) having a plurality of printing elements (56) spaced across the width and around the periphery thereof and carrying ultraviolet-curable ink. 3. An apparatus according to claim 1, characterized in that said printing means (52, 56; 86, 88) includes a reciprocating printing unit having a plurality of spaced printing elements (88) and carrying ultraviolet-curable ink. 4. An apparatus according to either claim 2 or 3, characterized in that said ink is letterpress black. 5. A process for printing bar codes (94, 96) on a continuous web (36, 82) of absorbent material, characterized by the steps of providing printing means (52, 56; 86, 88) containing a supply of ultraviolet-curable ink, advancing the substrate along a path past the printing means (52, 56; 86, 88), driving the printing means (52, 56, 86, 88) for sequential printing of bar code arrays on said web (36, 82) during advancement thereof, and drying the printed bar code arrays (94, 96) with ultraviolet radiation immediately after the printing operation. 6. A process according to claim 5, characterized by the steps of unwinding said web (36) from a supply roll (38) at one side of the printing means (52, 56; 86, 88) and rewinding said web (36) onto a take-up roll (42) at the other side of the printing means (52, 56; 86, 88). 7. A process according to claim 5, characterized by the steps of unfolding said web (82) from a pack (84) at one side of the printing means (52, 56; 86; 88) and refolding said web (82) onto a pack (92) at the other side of the printing means (52, 56; 86, 88). 8. A process according to claim 5, characterized by the steps of unwinding said web (36) from a supply roll (38) at one side of the printing means (52, 56; 86, 88) and folding said web (36) into a pack (124) at the other side of the printing means (52, 56; 86, 88). 9. A process according to claim 8, characterized in that the folding of the printed web (36) is performed by guiding said web (36) through a passageway formed by swingable guides (116, 118) and directing said web (36) into folds by cooperating members (120, 122) positioned above said pack (124).

Inventors: GRUTTEMEYER FREDERICK ERNST, GRUTTEMEYER, FREDERICK, ERNST
Applicants: NCR CO, NCR CORPORATION
Application year: 1987
Main classification: B41K3
IPC codes: B41F17, B41F23