FORM - 2
THE PATENTS ACT, 1970 (39 OF 1970)
COMPLETE SPECIFICATION
(See Section 10)
TITLE OF INVENTION


"A System for Seamless Flexographic Printing and process thereof

(a) Bilcare Limited (b) a company registered under the companies Act 1956 and (c) having its office at 601 ICC Trade Tower, Pune 411 016, India
The following specification particularly describes the nature of the invention and the manner in which it is to be performed.


Field of the Invention
The present invention relates to flexographic printing without the use of seamless cylinders / sleeves to achieve continuous printing of line(s) /band(s) / pattern(s) without breaks or discontinuities in the printed matter.
Background of the invention
Flexographic printing incorporates and involves the use of inked photopolymer plate for making the print impression when contact is established with a web with appropriate pressure. Generally flexographic printing presses have two or more stations enabling them to print two or more colors, A typical conventional printing station is depicted in Figure 1. It comprises of an irik reservoir, a fountain roll, an anilox roller assembly, a plate cylinder, a doctor blacie, an impression cylinder and a plate sleeve. The ink reservoir supplies ink to the fountain roll and this in turn provides ink in bulk Quantity to anilox roller assembly. Tbe^ArjjJox roJJer picks the ink from ink reservoir and the excess ink is wiped off by a Doctor Blade.
A plate mounting sleeve conventionally known a$ plate cylinder is a metallic cylinder placed between the Anilox Roller and the Impression Cylinder. The anilox roller assembly is brought in contact with the printing plate (PRT PLT) that is mounted on the Plate Cylinder (PLT CYL 1A) to deposit its ink onto the image areas in desired quantity. The plate mounting sleeves (PLT CYL 1A) are required in various diameters. To have desired number of image prints or print repeats around a Plate Cylinder (PLT CYL 1A), the existing Plate Cylinder (PLT CYL 1A) can be removed and another new Plate Cylinder (p|_T CYL 1A) is brought in position. A double sided sticky tape is applied on to the Plate mounting Sleeve (PLT SLV 1A) to mount a printing plate over the Plate mounting Sleeve.
The material to be printed, or web or substrate (SB§T), passes between the Plate mounting sleeve (PLT CYL 1A) and the Impression Cylinder having a super-finish surface (IMP CYL 1B). The Impression Cylinder (IMP CYL 1B) backs up and supports the web or substrate (SBST) as it contacts the printing plate (PRT PLT). The gap, or nip, between these two cylinders {Impression Cylinder (IMP CYL 1B)

& Plate Cylinder (PLT CYL 1A)} is maintained correctly to exert proper printing pressure.
Generally, the printing Plate (PRT PLT) is mounted on plate sleeve (PLT SLV 1A) on the plate mounting machine.
The position of the plate is fixed accurately with the help of cross-line view precision cameras on the plate mounting machine. Invariably a gap remains across the width of the said printing plate as the plate edges cannot be completely closed and this results in breaks or discontinunities in the printed matter. To avoid such breaks, continuous sleeves have to be used which are seamless tubes made from special polymers. Patterns engraved may be in the form of a continuous graphics, picture, line, alpha-numeric details etc.
Though continuous sleeves are extensively used in flexographic printing, each sleeve is specific to an artwork and therefore cannot be reused for any other art work resulting increased inventory and working capital. Further different sized adapters are required for these continuous sleeves adding further to the cost structure..
United States Patent 7285177 discloses a thin-walled reinforced sleeve with integral compressible layer. It comprises of a sleeve for a print cylinder comprising a fiber reinforced, thin-walled material and having a seamless surface ready to be covered with a surface material. The sleeve may be used in flexographic printing, either as a support for photo-polymerized printing plates or rubber layers.
Hollow cylindrical sleeves of various configurations are known from U.S. Pat. Nos. 4,391,898; 4,503,769; 4,554,040; 4,601,928; 4,656,942; 4,812,219; 4,949,445; 4,963,404; 5,468,568; 5,819,657; 5,840,386; 6,038,971; and 6,038,975. Generally, these prior art sleeves consist of a plurality of associated concentric layers, typically an outer printing or surface layer and one or more underlying support layers.
U.S. Pat. No. 4,503,769, discloses a metal-coated, thin-wall plastic printing

cylinder for rotogravure printing. An expanding mandrel containing journal bearings internally and laterally supports a metal coated, hollow, plastic cylindrical sleeve.
U.S. Pat. No. 4,949,445, teaches a cylindrical sleeve with a metal or plastic core which is covered with a compressible material onto which a perforated (stencil) printing sleeve may be mounted. U.S. Pat. Nos. 4,601,928, 4,554,040, and 4,391,898, teach cylindrical printing sleeves formed on about a woven fabric mesh using sheets of photopolymer which are wrapped about the mesh core.
U.S. Pat. No. 4,656,942, discloses a printing apparatus using flexible metal sleeves to transfer ink and a method of mounting the sleeves. The sleeves are made by electro depositing metal in a form that is very thin, readily collapsible, and imperforate. The outer surface of the sleeve is coated with a flexible, microcrystalline, wholly inorganic photoconductive material. One example of this type of material is sputtered ultra-pure cadmium sulfide.
U.S. Pat. No. 4,812,219, discloses a method of producing a surface sleeve for mounting on a plate cylinder in a printing process. A cylindrical sleeve made from an electrically conductive material such as nickel is mounted onto a supporting mandrel with a cylindrical outer surface. An inner metal layer is electrolytically deposited on the outer peripheral surface of the sleeve and an outer copper layer is electrolytically deposited on the inner metal layer. The printing pattern is etched directly on the copper layer or on a chrome layer covering the copper layer. Subsequently, after the engraving of the printing pattern, the opposite outer portions of the sleeve are removed due to the increased thickness of the metal layers.
U.S. Pat. No. 4,963,404, discloses a process for the production of a thin walled coated cylinder and an ink transfer roller. A thin-walled, seamless nickel cylinder is coated by plasma spraying a ceramic fluorocarbon polymer thereon. An adhesive layer of metal is applied between the surface of the cylinder and the coating. The

adhesive layer consists of at least two metals reacting exothermally with each other under plasma spraying conditions.
U.S. Pat. No. 5,468,568, is directed to a printing roller designed for a gravure printing process with a sleeve of fiber-reinforced thermoplastic which is then plasma sprayed to form a coating of copper or a copper alloy. A variety of fibers and plastics are disclosed for use in the sleeve, which is stated to have a wall thickness of less than about 3 mm.
U.S. Pat. No. 5,819,657, teaches a carrier spacer sleeve for a printing cylinder. The patent contains a discussion of the use of thin sleeves in flexographic printing operations. Such thin sleeves are designed to be air mounted onto the carrier spacer sleeves to enable a printer to modify the effective diameter of printing cylinders for jobs of different print repeat lengths.
U.S. Pat. No. 5,840,386, describes a sleeve that is adapted to be mounted onto a mandrel. The sleeve is used to transfer ink in anilox or gravure printing processes. The sleeve includes an inner layer, an intermediate compressible layer, and a metal outer layer. The inner layer may be fabricated from fiber-reinforced plastic and may be in the form of a DuPont Cyrel.TM. sleeve.
U.S. Pat. No. 6,038,971 discloses a method and apparatus for producing a screen-printing stencil. A covering layer is applied to certain areas of a fine-mesh screen corresponding to a predetermined printing design. The screen is closed on the backside by a cylindrical support to prevent the covering liquid from passing through the screen. The support may be a thin w&Jled metal cylindrical sleeve.
U.S. Pat. No. 6,038,975, discloses a gapless sleeve for offset printing. The sleeve includes a roller core and a thin intermediate layer which can be either a self-adhesive plastic sheet or a coating of plastic, metallic, or ceramic material.

The challenges associated with high costs of continuous flexographic printing especially in developing countries relate to obviating the use of artwork specific continuous sleeves that are non-usable for other artworks add to the inventory. The unmet need therefore demands development of systems and processes that make it possible for continuous printing of matter / graphics / bands without breaks or discontinuities in the machine web or axial direction on substrate without the use continuous sleeves. Further issues related to continuous sleeve and dedicated adaptors for positioning and gripping the continuous sleeve also need to be addressed.
Summary of the Invention
The main object of the invention is to provide a system and process for flexographic printing without the use of seamless cylinders /sleeves to achieve continuous printing of line(s) /band(s) / pattern(s) without breaks or discontinuities in the printed matter in the machine web or axial direction of the substrate
Another object of the invention is to reuse the same means for seamless printing for varying artworks.
Another object of the invention is to provide a system and process to segregate seamless means to print continuous graphic(s)/ lines / bands and means for printing discontinuous matter.
Another object of the invention is to provide a reusable seamless means.
Yet another object of the invention is to provide flexibility to use the seamless means despite repeat length of the printing plate wherein number of impressions repeated in a length that is equal to circumferential length of the cylinder.
Another object of the invention is to provide a plate sleeve assembly to enable continuous printing of matter and/or graphics on the substrate without using dedicated continuous sleeves.

Another object of the invention is to provide a process to print continuous matter / graphics on a substrate obviating the problems of occurrence of gaps in lines or bands in the machine web or axial direction on the substrate.
Yet another object of the invention is to provide a process and system for continuous printing of matter/ graphics on substrate using one or plurality of stations.
Thus one aspect of the invention provides a system and a process comprising:
a continuous sleeve comprising a plate cylinder assembly comprising
a plate sleeve mounting shaft provided with openings on its cylindrical surface;
plate sleeve that is adapted to be mounted on the said shaft;
a means to attach the said sleeve to a printing plate;
one or plurality of ring /s adapted to be mounted on the said sleeve
wherein the said plate sleeve is optionally adapted to mount a printing plate
wherein the said plate sleeve optionally is adapted to mount photo-polymer
printing plate that is engraved with the matter preferably axially disposed between
the said rings;
wherein
in one of the aspects the printing process comprises of passing the substrate
through first station that comprises of a conventional cylinder mounted with a
photo-polymer printing plate
wherein the matter, preferably text matter is printed on the said substrate using
photo-polymer printing plate followed by passing the said substrate through the
second station wherein the continuous matter/ graphics / bands is printed with the
aid of said continuous sleeve using said ring/s
wherein
in other aspect of the invention the printing process comprises of passing the substrate through the first station that comprises of the said continuous sleeve with photo-polymer printing plate that is engraved with the matter preferably axially disposed between the said composite material rings wherein prefereably

text matter is printed using the said photo-polymer plate and continuous matter / graphics is printed using the said ring/s.
Description of the Invention
Definitions:
Seamless Cylinder / continuous sleeves: Seamless tubes made with desired
engraved pattern that are mounted on an adaptar
Features and advantages of the invention will become apparent in the following
detailed description and the preferred embodiments with reference to the
accompanying drawings.
Figure 1 Schematic of the prior art (Sheet 1)
Figure 2 Schematic of the system (Sheet 2 )
Figure 3 Schematic of the product (Sheet 2)
The system of the present invention is depicted in Figure 2. It comprises of a continuous sleeve / ITR round assembly 1 that comprises of a plate cylinder assembly 2. The plate cylinder further comprises of plate sleeve 3 mounted on the mounting shaft 4. The said shaft is provided with openings (not shown) on its cylindrical surface. The plate sleeve 3 is adapted to be mounted on the said shaft 4. One or plurality of seamless means, preferably composite material ring /s 8 are distanced apart and adapted to be mounted on the said sleeve as shown in the Figure. The said ring comprises of a hard core and a relatively soft profiled outer portion (not shown). In one of the embodiment, a double side adhesive tape (not shown) that is adapted to attach to the said sleeve to photo-polymer printing plate (not shown) that is engraved with the matter preferably axially disposed between the said rings 8. The substrate 9 is passed through wherein the said rings causes the continuous impressions / printing lines indicated as 10.
The printing process comprises of passing the substrate through first station that comprises of a conventional cylinder mounted with a photo-polymer printing plate

wherein the matter 30, preferably text matter is printed on the said substrate using photo-polymer printing plate as shown in Figure 3(a). This is followed by passing the said substrate through the second station wherein the continuous matter / graphics, preferably continuous lines 31 are printed distanced apart such that the printed matter 30 is accommodated in between these lines with the aid of said continuous sleeve using said ring/s as shown in Figure 3(b). The final product is shown in the Figure 3(c).
In another embodiment the printing process comprises of passing the substrate through the first station that comprises of the said continuous sleeve with photo-polymer printing plate that is engraved with the matter preferably axially disposed between the said composite material rings wherein prefereably text matter is printed using the said photo-polymer plate and continuous matter / graphics is printed using the said ring/s.
In yet another embodiment the said ring profile and the said engraved photo-polymer printing plate are adapted to be inked with different colours on the same station using localized pads.
In yet another embodiment the art work for the said printing plate is configured and engraved so as to segregate line(s) /band(s) / pattern(s)) from matter.
Thus it is evident that the synergistic assembly of the said ring/s mounted on the said sleeve along with the use of the photo-polymer printing plate on the same cylinder thereby segregating the seamless means (to print continuous matter/ graphics/ bands), that is ring and means for printing discontinuous matter results in obviating problems associated with the conventional continuous sleeve enabling flexibility of using the same cylinder for diverse patterns resulting in substantial reduction in the printing cost.

We Claim
1. A system for flexographic printing comprising
a continuous sleeve comprising a plate cylinder assembly comprising
a plate sleeve mounting shaft provided with openings on its cylindrical
surface;
plate sleeve that is adapted to be mounted on the said shaft;
a means to attach the said sleeve to a printing plate;
one or plurality of ring /s adapted to be mounted on the said sleeve
wherein the said plate sleeve is optionally adapted to mount a printing
plate.
2. A system for flexographic printing as claimed in claim 1 wherein the printing process comprises:
passing substrate through a first station that comprises of a plate sleeve mounting shaft, a plate sleeve that is mounted on the said shaft, a printing plate
wherein the matter, preferably text matter is printed on the said substrate using printing plate followed by passing the said substrate through the second station wherein the continuous matter / graphics is printed with the aid of said continuous sleeve using said ring/s.
3. A system for flexographic printing as claimed in claim 1 wherein the printing process comprises of passing substrate through the first station that comprises of the said continuous sleeve with photo-polymer printing plate that is engraved with the matter preferably axially disposed between the said composite material rings wherein prefereably text matter is printed using the said photo-polymer plate and continuous matter / graphics / pattern is printed using the said ring/s.
4. A system for flexographic printing as claimed in claim 1 wherein the said means to attach the said sleeve to the printing plate is a double side adhesive tape.

A system for flexographic printing as claimed in claims 1-4 wherein the art work for the said printing plate is configured and engraved so as to segregate line(s) /band(s) / pattern(s)) from matter.
A system for flexographic printing as claimed in claims 1-5 wherein the printing plate is a photo-polymer type of printing plate.
A system for flexographic printing as claimed in claims 1-6 wherein the ring comprises of a first material layer that is adapted to mounted on the said plate sleeve and a second layer with a profiled portion provided on the said first layer wherein the said first layer is relatively harder than that of the said second layer.