Title of Invention

"METHOD OF INDIRECT PRINTING ON EMPTY WOVEN SACKS/BAGS/CARRYBAGS"

Abstract

A method of indirect printing on empty woven sacks/bags/carry bags has been disclosed, comprising of a method wherein printing of contents of a computerized design containing half tone impressions, photographs, pictures, images containing multiple colours/shades is done on a specified transparent film, by using negatives of different colours and by using the chrome-plated half tone cylinders, treating and gumming of such printed transparent film and affixing the same on empty woven sacks/bags/carry bags in such a manner that printed matter on such transparent film becomes visible on empty woven sacks/bags/carry bags as if the contents were printed directly on such empty woven sacks/bags/carry bags.

Full Text

The present invention relates to a method of indirect printing on empty High Density Poly Ethylene (HOPE) sacks and other woven sacks, bags and carry bags and more particularly to a method of durable and non-fading indirect printing on HOPE and other woven sacks/bags/carry bags by printing the contents on specified transparent film and affixing such printed transparent film on a woven sack or bag or carry bag in such a manner that printed matter on the transparent film becomes visible on woven sack or bag or carry bag as if the contents were printed directly on the woven sack/bag/carry bag. The object of present invention is to overcome certain serious drawbacks in prior art. In prior art, contents on the empty woven sacks are printed by using lamination printing. That process is quite cumbersome, expensive, less effective and prone to fading. When the printed woven sacks are wiped with a cloth or other material to remove dust or other particles settled on the woven sacks, the printed matter on woven sacks fades away and loses its utility. The exposure to sun, heat, rain and water also blurs the printed impressions on woven sacks. Doing designing on empty woven sacks is expensive than that in present invention. To avoid all this is the object of the present invention. The present invention is a new method for doing durable and non-fading indirect printing on the empty HOPE woven sacks and other woven sacks/bags/carry bags. The present invention is very cost effective and the printing resulting therefrom is of very fine quality with more clarity, sharpness, brightness and long lasting, non-fading impressions and hence durable. Many limitations of the prior art have been overcome through the present invention. Another object of the invention is to print half tone impressions, photographs, pictures, images containing overlapping colours/shades on the empty HOPE and other woven sacks/bags/carry bags, which is not possible in the prior art. Brief Description of the Present Invention The present invention relates to a method of indirect printing on empty High Density Poly Ethylene (HOPE) sacks and other woven sacks, bags and carry bags and more particularly to a method of durable and non-fading indirect printing on HOPE and other woven sacks/bags/carry bags by printing the contents on specified transparent film and affixing such printed transparent film on a woven sack or bag or carry bag in such a manner that printed matter on the transparent film becomes visible on woven sack or bag or carry bag as if the contents were printed directly on the woven sack/bag/carry bag itself. In the present invention, the contents in the form of words, numerals, manufacturer's name, logos, net weight, batch no., date of manufacture and other mandatory information to be printed on woven sack is first composed and enshrined into a computerized design prepared on a computer. A significant feature of the present invention is that by using this invention, half tone multi-colour impressions, photographs and images containing overlapping but distinct shades/colours, can also be printed and made visible on woven sacks/bags/carry bags without loosing clarity. The photographs, pictures and images to be printed on empty woven sacks, are scanned into a computer, edited and placed at appropriate location in the computerized design. Half tone impressions are composed from such pictures and photographs. The colour scheme of the computerized design is also determined. The size of the above contents and that of the computerized design is reduced or enlarged according to requirement and size of woven sack/bag/carry bag and a final computerized design is prepared. Unlike the prior art, the computerized design obtained in the above manner is not directly printed on woven sacks. Instead, the said computerized design is printed on a transparent Biaxial Oriented Poly Propylene (BOPP) film or any other transparent film material by making negatives of different colours of the computerized design and by making chrome-plated half-tone cylinders from such negatives and then by processing them on a Roto Graving Printing Machine and printing them on transparent BOPP film or such other specified transparent film material as may be available. Such printed transparent film is then securely and inversely sticked on one side of an empty HOPE woven sack/bag/carry bag in such a manner that the final computerized design printed on the transparent film becomes visible on the HDPE woven sack/bag/carry bag as if it were directly printed on such woven sack/bag/carry bag. The invention can be very well understood with the accompanying drawings. Figure 1 is a block diagram showing the prior art of printing on woven sacks/bags/carry bags, which is known as Flaxo Printing, which is a common method of such printing. Flaxo Printing is just like a rubber stamp method and Figure 1 also shows the block diagram of the plant used in the Flaxo-Printing method. The plant of Flaxo Printing mainly consists of a rolling steel cylinder, a rubber sheet conveyor belt, Ink Tub(s) and Ink Rolls.In the prior art of Flaxo Printing Method, the contents in the form of words, numerals, pictures, manufacturer's name, logos, net weight, batch no., date of manufacturing and such other information is printed on woven sacks by making big sized rubber stamps and printing their impression on woven sacks/bags/carry bags. The contents as described herein are engraved on flexible rubber and big sized rubber stamps are prepared. In Flaxo Printing method, half tone impressions cannot be created or printed on woven sacks/bags/carry bags. In Flaxo Printing plant, there is a rubber conveyor belt about 15 to 20 feet in length and 3 to 4 feet in width. This rubber belt is adjusted and tightened on 4 rollers. When one roller moves, the entire belt also moves and after completing the circle, the conveyor belt reaches at its starting place. This is shown as C-1, C-2, C-3 and C-4 in Figure 1. Apart from conveyor belt, two big iron cylinders shown as SC-1 and SC-2 in Figure 1 are used in the Flaxo Printing plant. For each colour, one cylinder is used. In Figure 1, IF-1 and IF-2 are two Ink Pots. The Ink Pot IF-1 is dipped in ink and it feeds ink to the Ink Pot IF-2. The Ink Pot IF-2 in turn, supplies the ink to Rubber Stamps S-1 and S-2. When these rubber stamps S-1 and S-2 move in clockwise direction, the belt moves in anti-clockwise (opposite) direction and the impression of the rubber stamps' is printed on the woven sacks. For different impressions, a woven sack has to pass through cylinders SC-1 and SC-2 each time. This is a manual process and a person places the woven sacks one by one on the conveyor belt. All the rollers, ink rollers and belt are synchronized as far as their movement is concerned. The woven sacks are then dried up. The Flaxo Printing method suffers from many shortcomings, particularly that the printed matter fades away and losses its colour and utility, when the woven sack is wiped with a wet cloth or any other wiping material to clean dust particles settled on it. Under the prior art, the printing can also be done by an alternative method called Screen Printing. In Screen Printing, a nylon cloth is tied firmly on a wooden frame and is treated chemically to get impression on it. Such chemically treated nylon cloth is called Screen, which acts like a negative. When this wooden frame is placed on the empty woven sack and colour is brushed on the Screen, the impression of the printed matter in one colour gets printed on the empty woven sack. To get an impression in different colour, a different Screen is used and the other colour is brushed upon it after the first colour dries up. Defects in Prior Art 1. Since excessive rubber is used in all stages of Flaxo- Printing, a slight undesired pressure on the rubber of either of rubber stamps or conveyor belt or ink rolls results in the failure of ink printing on the empty woven sacks. 2. In both methods of prior art, printing on empty woven sacks can be done only in 2 to 3 colours at a time. A second color on the same sack can be applied only after the first colour dries up and thus prior art is a longer process of printing. 3. The gap between applying two different colours has to be maintained for about 1 hour, which delays the process of printing. Thus the process of Flaxo Prinitng is time consuming. 4. In the prior art, the letters, words and numerals cannot be printed on woven sacks in very small sizes, which are less than 2-3 MM. 5. When the printed woven sack is exposed to sun, rain or packed material leaks out of the woven sack, the printing on the woven sacks fades away and printed contents and their colour looses its utility and durability. 6. When the dust and dirt settled on a printed woven sack is cleaned/wiped with a piece of wet cloth, the dust and dirt settles down in the pores of the woven sacks and the printed matter becomes blurred or invisible over a period of time. 7. The prior art of Flaxo Printing is coarse and rough method of printing on the woven sacks while the printing by using the present invention is very fine and smooth. 8. Half Tone Printing cannot be done by using Flaxo Printing method, whereas in the present invention Half Tone Printing is done. 9. The quality of printing resulting from Flaxo Pritning Method is quite inferior as compared to the printing resulting from the present invention. In fact, the quality of Flaxo Printing can be said to be 10% of the quality of printing resulting from the present invention because rubber stamp printing under Flaxo Printing has its own limits. Advantages and Improvements of the Present Invention over Prior Art 1. In the present invention the colour of printed contents on woven sacks does not fade away and thus the printing resulting from the present invention is long lasting, durable and it does not looses its utility over a period of time whereas in the prior art, when the printed woven sack is exposed to sun, rain or packed material leaks out of the woven sack, the printing on the woven sacks fades away and the printed contents and their colour looses its utility and durability. Further, when the dust and dirt settled on a printed woven sack is cleaned /wiped with a piece of wet cloth, the dust and dirt particles gather in the pores of the woven sacks and the printed matter becomes blurred or invisible over a period of time. 2. In both methods of prior art, printing can be done in only 2 to 3 colours and impression of each colour has to be separate. On the contrary, by present invention, one can do printing in more than 250 shades/colours. 3. A clear advantage of the present invention is that Half Tone Printing can be done on empty woven sacks, whereas in the prior art it is not possible. In present invention, Half Tone Impressions are created and then printed on empty woven sacks/bags/carry bags by using transparent film. Moreover, the overlapping of different shades is possible in the present invention. Although, the shades do overlap, yet a clear distinction in shades is also maintained and it remains visible on the printed woven sacks/bags/carry bags. The printing of half tone impressions and overlapping shades/colours is not possible in prior art. 4. In present invention, the photographs can also be printed on the transparent film and after affixation of the transparent film on empty woven sacks/bags/carry bags, such photographs are clearly visible on the woven sacks/bags/carry bags. Under prior art. the printing of photographs on woven sacks/bags/carry bags is not possible. 5. In present invention, by using a combination of two basic colours, the final printing on transparent film affixed on woven sacks can be done in 16 colours and by using a combination of 4 basic colours, the end printing on woven sacks can be done in 256 colours simultaneously, which is a clear advantage of the present invention over prior art. 6. By using the present invention, multi-colour printing on the transparent film can be done simultaneously which saves time whereas in the prior art of Screen Printing and Flaxo Printing, the multi colour printing on empty woven sacks/bags/carry bags cannot be done simultaneously. The second colour on the same woven sack can be applied only after the first colour dries up and thus prior art is a longer process of printing and the gap between applying two different colours has to be maintained. 7. The contents printed on transparent film affixed on woven sacks by using the present invention are glazed, shining, more clear and easily readable while in the prior art, the quality of printing is not very fine and the colour of the printed matter fades away and the printed matter looses its utility as the printed matter becomes blurred or invisible after certain period of time. 8. The printing by present invention is time saving and has more clarity, finer finish and better customer appeal as compared to prior art. 9 By using the present invention, the printing can be done in very small sizes (less than 2 MM) as well as in very big sizes whereas in the prior art, the letters, words and numerals cannot be printed on woven sacks in small size which is less than 2-3 MM. 10. In the present invention, the exposure of woven sacks to sun, heat and rain or water does not destroy the printing on them as the printing is actually done on a transparent film material and the said transparent film is affixed on the woven sack in inverse manner which covers the printed matter and protects the printed matter from direct exposure to heat or water. The dust particles settled above the transparent film can easily be cleaned without losing the colour(s) of the printed matter. On the contrary, in the prior art the printed matter always remains in direct exposure to sun, heat, rain and water and cleaning of dust particles settled on the printed area of woven sack results in fading away of the colours over a period of time. 11. In the present invention, the film coating on the printed matter also protects it from fading or loosing colours whereas in prior art, the film coating cannot be done. 12. By using the present invention, even the complex designs containing half tone impressions and photographs can be printed on woven sacks whereas in prior art only simple design work can be printed on the woven sack. 13. In the present invention, there is no need of drying up the woven sacks because the final computerized design printed on the transparent film dries up immediately after the printing is done on the transparent film. On the contrary, in the prior art the printing in one colour is followed.by printing in another colour after drying up the empty woven sack itself and after maintaining a gap between printing in two different colours. Moreover, in prior art, the printing cannot be done in more than 4 basic colours. Detailed Description of the Present Invention Figure 2 shows a flow chart of the method and process of the present invention. In the present invention, a computerized design consisting of half tone impressions, photographs, overlapping shades/colours, letters, words, numerals, manufacturer's name, logo, pictures, images and other complex designs, net weight, batch no., date of manufacture and other mandatory information to be printed on empty woven sacks, is prepared in the form of a computerized design using a personal computer (PC). The desired photographs, pictures and images to be printed on the woven sacks are scanned into PC and they are edited by using Image Processing Software. The edited pictures are inserted at appropriate places in the computerized design. The computerized design is further processed, edited and refined by using Design Processing Software. The colour scheme of the computerized design is determined. The size of the above contents and the computerized design is reduced or enlarged as per the requirement or size of the woven sacks and a final computerized design containing all ingredients is prepared and stored in the memory of PC. The final computerized design so obtained is not directly printed on the empty woven sacks/bags/carry bags. Instead such final computerized design is transferred from PC to a Recordable Compact Disk (CD) for making negatives of the computerized design as per pre-determined colour scheme. A separate negative is prepared for each colour used in the computerized design. Such negatives are then processed to obtain chrome-plated half tone printing cylinders for further processing on Roto Graver Printing Machine. The Roto Graver Printing Machine prints the multiple impressions of the final computerized design with all its colours, from the chrome plated half tone printed cylinders to a long roll of transparent BOPP film or such other transparent film material as available, in a series. The roll of transparent film is glazed on one side. The printed surface of the roll of transparent film is then treated on a Treating Machine so that printed film, one surface of which has become plain due to printing, becomes rough and coarse. The coarse surface is suitable for gumming, which is the next stage of this method. The printed transparent film is then gummed on the coarse surface and transparent film roll is ready for being affixed on several woven sacks/bags/carry bags in a continuous series. The printed transparent film is then securely sticked on the woven sacks by using a Roll Fixing Machine. Figure 3 is a block diagram showing the manner and process of Roll Fixing Machine and the plant used for the purpose of sticking the transparent film on woven sacks. The main parts and working of Roll Fixing Machine and the plant used in the present invention is explained below: The printed and gummed transparent film roll, obtained in the manner explained above, is mounted on the steel cylinder (C1), which can freely rotate on its bushes and one end of the transparent film roll is then opened and passed between a pair of Rubber Rollers C2 and C3 mounted on M/S Steel frame (F1) and Bearing Brackets B1 and B2 which are adjustable for adjusting the gap of the Rubber Rollers for pressure adjustments, A-1 being adjustive arrangement. Drive is given through a Pixon and Pulley Arrangement. The empty unprinted woven sacks/bags/carry bags are then fed through the Feeding Guide (F2) cum Table continuously. The transparent film passes through the hard rubber rollers C2 and C3 with its gummed surface up and when the empty woven sack/bag/carry bags come in contact with the gummed surface of the transparent film, the transparent film gets securely affixed on the woven sacks/bags/carry bags and such woven sacks/bags/carry bags together pass through the rollers C2 and C3 to make a continuous reel of finished printed woven sacks/bags/carry bags. This continuous reel is then made to pass over a cylinder C4 where the printed and glazed side becomes visible and then it passes through a Slitting Table (S), which is activated through the Pinion and Pulley arrangement for slitting and separating each printed woven sack/bag. The complete mechanical arrangements are mounted on a strong angular Chassis (CH). The printed empty woven sacks/bags are now ready for packing/filling. The use of transparent BOPP or such other transparent film as available, protects the printed contents from direct exposure to heat and water, maintains the luster of printed matter and thus results into a durable and non-fading printing on the BOPP transparent film affixed on the woven sacks/bags/carry bags though some other type of transparent film can also be used. Best Method of Performing the Invention (a) Because the complex designs can be prepared conveniently and in best quality by using a PC and the scanned pictures can also be embedded in the computerized design at appropriate location and in appropriate size, as per requirement, hence the computer designing has been used in the present invention. (b) Since the final computerized design occupies large disk memory and space of the PC and it is processed further for making negatives and for chrome plated half tone cylinders, hence the final computerized design is first transferred to a medium of recordable Compact Disk (CD), which has a larger memory space, as compared to the mediums of Floppy Disks and Zip Drive and thus a CD is capable of holding a computerized design for shifting the same to another PC for further processing on Roto Graving Machine. (c) Since the processor now composes negatives by using PCs, which is much better and advanced platform than the earlier technique of composing negatives on cameras, hence the medium of a CD has been used for transferring the final computerized design from one PC to another. (d) Since the final computerized design contains either single colour or multi colour/shade designing, as per requirement, hence separate negatives are prepared for each colour/shade used in the final computerized design. (e) Because the printing source for Roto Graving Machine, are chrome-plated half tone cylinders only, hence the chrome-plated half tone cylinders have been prepared and used. (f) Computerized designing and Roto Graving Printing results in high and fine quality printing, hence these methods and processes have been used for the purpose of present invention. (g) Since the quality of printing on transparent BOPP film is superior to the quality of printing on PVC or other plastic films, hence the transparent BOPP film has been used in the present invention, However, any other transparent film such as PVC film with one surface glazed and other treated, can be used for the purpose of present invention. (h)The treating of transparent film is necessary because, when certain matter is printed on the transparent film, the upper surface of the printable area of such transparent film becomes plain by virtue of printing, but for the purpose of gumming and sticking a coarse surface is required for best results, hence the treating of one surface of the transparent film is done. (i) Because, for secure sticking on woven sacks/bags/carry bags, gumming is necessary on one surface of the transparent film, hence the gumming is done for the purpose of present invention. (j) A roll of transparent BOPP film has been used as solo tape roll in the present invention because the transparent BOPP film is affixed on several woven sacks in a continuous series. (k)The Roll Fixing Machine has been used in the present invention in order to avoid any curves or twists on the transparent film and empty woven sacks and to securely stick the transparent film on woven sacks/bags/carry bags. (I) During the course of affixing transparent film on empty woven sacks, the woven sacks get attached to each other through the medium of transparent film roll, hence the slitting of the film has been done and the attached empty woven sacks are detached from each other. I claim: 1. A method of indirect printing on empty woven sacks/bags/carry bags comprising the steps of :- Preparing a computerized design containing half tone impressions, photographs, images, pictures, overlapping colours/shades as herein described. Preparing negatives of different colours in consonance with the colour scheme of the final computerized design, half tone impressions as herein described. Preparing the chrome-plated half tone cylinders from the negatives obtained in the previous step. Printing the final computerized design containing half tone impressions etc. on transparent BOPP film or such other transparent film material as available, which has one surface glazed and the other surface treated. Treating and Gumming of the transparent film material for making such transparent film ' material fit for affixing on empty woven sack/bags/carry bags; and Affixing the printed transparent BOPP film or any other transparent film material inversely on empty woven sacks in such a manner as to make the printed matter of the transparent film, visible on empty woven sacks/bags/carry bags as if it were directly printed on the woven sacks/bags/carry bags. 2. A method as claimed in Claim 1 wherein halftone impressions, overlapping shades/colours of an image and photographs are indirectly printed on ^j empty woven sacks/bags/carry bags by using transparent film as herein described; 3. A method as claimed in Claim 1, wherein a final computerized design containing half tone impressions is prepared as per requirement and printed on empty woven sacks/bags/carry bags; 4. A method as claimed in Claim 1, wherein multi colour printing is done on the transparent BOPP film or such other transparent film as available, in such a manner that the transparent film material is suitable for being affixed on empty woven sacks/bags/carry bags. 5. A method as claimed in Claim 1, wherein the computerized design is printed on transparent BOPP film or any other transparent film material as available and such printed transparent film is affixed on woven sacks/bags/carry bags. 6 A method as claimed in Claim 1. wherein the negatives of different colours are prepared in consonance with the colour scheme of the final computerized design, half tone impressions, overlapping but distinct clours/shades, photographs, images and pictures. 7. A method as claimed in Claim 1, wherein the half tone impressions are prepared from the negatives of different colours for further processing and printing of the design on transparent film material. 8. A method as claimed in Claim 1, wherein the final computerized design is printed on transparent BOPP film or any other specified transparent film material by using chrome-plated half tone cylinders. 9. A method as claimed in Claiml, wherein the treating and gumming of the specified transparent film is done for making such transparent film suitable for affixing on the empty woven sacks/bags/carry bags. 10. A method as claimed in Claim 1, wherein the printed transparent film is inversely affixed on empty woven sacks/bags/carry bags in such a manner as to make the printed matter of the transparent film visible on empty woven sacks/bags/carry bags as if it were directly printed on such empty woven sacks/bags/carry bags. A method as claimed in Claim 1, wherein the printing of half tone impressions, photographs, pictures, images containing overlapping colours is done on specified transparent film and such transparent film is affixed on empty woven sacks/bags/carry bags, hesian cloth, polyester, acrylic, cotton, mixed cloth, craft paper, hand made paper and other packaging papers.

Documents:

626-del-2001-abstract.pdf

626-del-2001-claims.pdf

626-del-2001-correspondence-others.pdf

626-del-2001-correspondence-po.pdf

626-del-2001-description (complete).pdf

626-del-2001-drawings.pdf

626-del-2001-form-1.pdf

626-del-2001-form-13.pdf

626-del-2001-form-19.pdf

626-del-2001-form-2.pdf

626-del-2001-form-26.pdf