FR2513941A1 - PROCESS FOR THE CONTINUOUS PRODUCTION OF PRE-PRINTED MATRICES AND MATRIX THUS PRODUCED - Google Patents

Abstract

THE INVENTION RELATES TO A PROCESS AND AN APPARATUS FOR THE CONTINUOUS PRODUCTION OF PRE-PRINTED DIES INTENDED FOR DUPLICATION IN ALCOHOL. A CONTINUOUS STRIP 11 IS PRINTED ON A FIRST SIDE IN A FIRST PRINTING STATION 12, THEN RETURNED SO THAT ITS SECOND SIDE IS PRINTED IN A SECOND STATION 22 WHICH INCLUDES A ROTARY SCREEN PRESS. THE INK USED IS A THERMAL FUSE INK OR A SOLVENT BASED INK. AFTER PRINTING, STRIP 11 IS CUT INTO DIES WHICH CAN THEN BE STACKED OR COLLATED AND ASSEMBLED INTO BROCHURES. FIELD OF APPLICATION: PRODUCTION OF PAPERS BY DUPLICATION WITH ALCOHOL, HOT TRANSFERS, ETC.

Description

The invention relates to pre-printed matrices and a method of

  production of dies for alcohol duplication systems, iron on transfers and others, and

  it relates more particularly to a printing process

  on a first face of a continuous strip by means of a conventional printing press and, on the other side, by means of a hot-melt ink or an ink based

  of solvent, using a rotary screen printing press.

  Alcohol duplication is a widely used and particularly interesting process because of its low copy cost and low equipment cost, and also because it does not require any special training for the implementation. or in use of equipment This process is often used by teachers and teachers for the production of copies

  examinations and copies of subjects of instruction In gen-

  Alternatively, a matrix or master copy is made and is then used to produce multiple copies as desired. Generally, an alcohol duplication matrix comprises a substrate, usually made of paper, carrying a reflected image, formed by ink, information to be reproduced. The ink, for example a hot melt ink, carried by the matrix contains a soluble dye in a gasoline or alcohol and which, when pressed in momentary printing contact with a sheet of paper previously wetted with a solution of gasoline or alcohol, transfers the dye from the matrix to the sheet At each copy produced, a

  some of the ink in the matrix is used.

  To have a long production time for copies, and to produce readable printed copies, the matrix must have an image, formed by ink, relatively

  thick and uniform, and the image must have defined edges

clearly.

  Initially, the dies were produced individually from a transfer sheet having a surface coated with an alcohol duplicating material With the help of a typewriter, for example, a certain portion of the material carried by the transfer sheet was transferred onto a sheet covering the sheet by punching the upper sheet causing the printing of the ink, by crushing, on

this top sheet.

  It is also known to print alcohol matrices in advance using appropriate ink compositions. One reason for this is that the teacher can use such pre-printed matrices to produce copies for students. , on a given subject, without having to compose the work itself In other words, images (text, mathematical problems, etc.) are formed in reverse printing, by means of an alcohol duplication ink, directly on the back side of a sheet to form a matrix, instead of being produced by a transfer technique at the time of preparation of the exam by the teacher Other uses of pre-printed matrices include the field of recreation and the fields in which dies are used to produce images on wood, ceramics, cloth, leather, etc. and in the field of games for the production of images in coloring books, games, etc. . Such preprinted matrices for alcohol duplication may also have printed images

  in the normal way on their front surface,

  in alignment with the reverse printing image on the back side Printing on the front surface gives the user a visible and easily readable image

images printed in reverse.

  However, with pre-printed duplicating dies, the ink often oozes through the paper to the front surface to produce a "halo" effect on

  image on the front surface This is particularly

  criticism in the field of matrices pre-

  because such matrices are printed in large series more than a few months or years before the date of use and must be stored for long periods of time The longer the storage period, the greater the risk of "halo" is large due to variations in humidity and temperature occurring during this period. In some circumstances, the "halo", if large enough, renders the sheet aesthetically undesirable and even unacceptable, because the print formed on the front side of the sheet

  is obscured and made illegible by the "halo".

  Currently, a "halo" solution is to use ink compositions that do not ooze, as described, for example, in U.S. Patents Nos. 3,962,526 and 4,005,237 and optionally treat the paper with an oleophobic material to resist seepage Another solution to the "halo" effect is to obtain alignment too

  accurate as possible between the impression formed on the

  front side and the duplicating ink with alcohol applied in reverse printing on the back side in a process

  discontinuous printing sheets with silk screen-

  Offset were prepared in batches in a process by

  batches or batch process, each of the printing stages

  made on a given "lot" of individual sheets

  is executed by a different operator: an offset printing operator, an operator of printing on the screen

  of silk, a cutting operator, an assembly operation

  etc. This can lead to loss of material

  and loss of labor time.

  U.S. Patent 3,336,864, which discloses an apparatus for screen printing silk or screen printing, allowing the printing of a first

  image on the surface intended to support the serial paper

  graphie, is also interesting in this regard The paper is then placed on the ink print performed on the surface The screen is then placed on the surface

  paper and ink is applied again.

  the pressure which is then exercised

  the ink on both sides in proper alignment.

  This obviously constitutes a discontinuous process.

  Moreover, with such discontinuous processes,

  there are often difficult alignment issues.

  Since the printed sheets can be thin and / or transparent, the inks, since they must form the backside of the print on the front side, are visible and appear out of alignment with the formed figures and printing. on the front surface if they are not in precise alignment In general, the lack of accuracy of the alignment results from the fact that each sheet must be treated individually by different operators and by different elements of the printing equipment. course of the different stages of printing. It would be more desirable to continuously impregnate an ink, particularly an alcohol duplicating ink, on the back side of a sheet, in alignment with the impression made on the front surface.

  conventional continuous printing processes are not suitable

  For this purpose, continuous double-sided printing, such as that described in U.S. Patent No. 530,831, does not perform alignment and

  can be used with duplication inks in

  cool Ordinary embossed printing processes such as conventional letterpress and flexographic printing do not apply enough ink to achieve

  pre-printed matrices of alcohol duplication.

  The repressed ink tends to form a bead on the periphery

  Image of the elements of the image, but a small amount of ink remains in the character lines A continuous process for printing alcohol duplication matrices is described in U.S. Patent No. 4 152,986 using a raised print area

  raised, formed by exposure, through a half

  screen, a photosensitive printing plate However,

  this process also suffers from the impossibility of

  With the ink, a uniform image of sufficient thickness and sharpness. Typical hollow printing processes such as rotogravure are not economically feasible for the production of small series of copies. As a result, there is still

  the need for a continuous process with little co-operation

  inks, with a thickness and a

  uniform sharpness on diesheets

  to give the desired number of copies, while eli-

  undermining the problem of aligning printed images

on the opposite side of the paper.

  The present invention addresses this need by a method of printing a face of a continuous web by

  offset, typography, engraving or flexography, and impres-

  The process of the invention is fast, efficient and inexpensive, because of the greater quantity of matrices that can be produced at a higher speed.

  and with a smaller workforce than those

  in a "batch" printing process or

  Moreover, by producing matrices by the

  transferred from the invention, the problem of the alignment of the im-

  pressure on the respective faces of the strip, which often arises when printing such matrices, is eliminated. According to the method of the invention, a continuous strip of material, for example paper or fabric,

  to be printed is introduced in a first printing station

  o a desired pattern, design, print or image is printed by an offset, typographic process,

  engraving or flexography It is possible to use

  several print stations to print different

  parts of the desired pattern, design, or printing, or to print with different colors of ink Printing on the first side of the tape can be made either from above or from below the tape is first printed from above, it must then be returned (for example by means of conventional rollover bars) before printing on the opposite side In all cases, the second side to be printed on the screen of silk is so

  arranged so as to be oriented upwards.

  The web is then directed to a second printing station where the opposite side of the web receives by printing a reverse image produced by means of one or more rotary screen printing presses. In the rotary screen printing press, the web is advanced between

  two rollers The upper roll has a cylindrical screen

  hollow ink on which the inverted image to be printed has been prepared The ink, for example a fluid hot melt material or a solvent-based ink, is introduced inside the upper roll and pushed back forcefully through the screen, In a preferred embodiment, the lower roll of the rotary screen printing press is magnetized and adjusts the pressure exerted by a scraper blade or magnetic scraper roller. placed inside the roll

  higher and forcing the ink across the screen.

  After the tape has been printed, she

  can be cut into sheets or individual matrices.

  In addition and as a variant of the cutting of the continuous strip into individual sheets, it is possible to carry out processing steps on or with the strip, comprising a winding of the continuous strip, the spraying of a protective material on the stripes. faces of the sheets printed by serigraphy, the introduction of leaves

  printed in envelopes, interleaving or assembling

  additional sheets, binding sheets with protective sheets to form a set, etc.

  The additional sheet may be a protection sheet

  such as tissue paper, waxed paper,

  paper impregnated with silicone, glassine, plastic

  or other, or it may be any other type of coated paper. When an alcohol duplicating ink is applied by screen printing on the back of the tape, it may be desirable to place a protective foil. on the latter by stapling, gluing, embossing, bonding by adhesive or otherwise. In these cases, it may be desirable to perforate the printed sheet so that it can be easily detached or separated from the protected sheet.

  then be collated to form a brochure.

  Since the tape is continually

  taken and kept in a tight state, subject to the

  given to the action of the continuous strip printing apparatus according to the invention, the alignment of the two images

  printed on both sides of the strip is obtained mainly

  by adjusting the speed of the tape and synchronizing

  nisation of the printing steps The reverse image

  the rotating screen is positioned by means of a

  tif of framing per feet mounted on the end ring of the screen to accurately align the image with the printed image from the previous pose Thus, once the speeds of the printing steps have been set in synchronism , the images printed on the tape can be aligned This alignment can be further maintained by conventional double-sided tape printing techniques such as the use of tape guides and automatic centering checking means which detect marks. printed on the tape, in the first printing station, and then adjust according to these marks

the second printing cycle.

  The object of the invention is therefore to produce

  pre-printed matrices perfected by means of a

  and a fast, efficient and inexpensive apparatus that produces these dies by printing a first face of a continuous web by offset, letterpress, engraving or flexography, and the opposite side with a screen printing ink applied by means of a rotary press

  silkscreen, in image-by-image alignment with the impres-

  made on the first side of the strip. The invention will be described in more detail with reference to the accompanying drawings by way of non-limiting example and in which:

  FIG. 1 is a schematic perspective view.

  illustrating the continuous printing process according to the invention; and Figure 2 is an elevation of the apparatus

  implementing the method of the invention.

  The invention will be described in its application to an apparatus for printing alcohol duplicating matrices, although it is obvious to those skilled in the art that the process of the invention may be somewhat modified. for the production of images on other substrates such as fabric, or for the production of hot-applied transfers, or of matrices for transfer under

  pressure for artistic and craft applications.

  As shown in FIG. 1, a roll 10 of a continuous strip 11, for example a strip of paper, is unrolled continuously so that the strip passes through a first printing station 12 or its first face receives by printing a pattern or a desired image The printing station 12 can use an offset printing, typography, engraving or flexography process. Optionally, a plurality of printing stations can be used to print different parts of the patterns or images.

  desired or to print these patterns or images in different

  The printing can take place either from above or from the bottom of the strip. As a variant of the invention, a blank plate can be used in the first printing station so that the first face

the tape is not printed.

  However, if the upper face of the band

  is printed, this tape must be returned before arriving

  worm at the next printing station For this purpose, the tape

  It is returned by means of a

  The device 14 comprises a turning rod 16 forming an angle of 450 with the direction of advance of the web, a guide roller 18 which is oriented perpendicularly to the direction of advance of the web, and a rod 20 of turning at an angle of 45 with the direction of advance of the band and an angle of 900 with the bead wire 16 After passing through the turning device 14, the band 11 is oriented from

  so that its unprinted side is facing upwards.

  Alternatively, if, in the initial printing station, the images or patterns are printed on the underside of the strip 11, the reversal device 14 of the

band becomes useless.

  The web is then directed to a second printing station 22 by which the opposite side of web 11 receives by printing an upside down or reverse image applied by means of one or more presses.

  in the rotary printing press

  graph, the band 11 passes on a guide roll 24

  and is advanced in the space between a roll of

  The upper roll 26 consists of a hollow cylindrical wire cloth having a large number of meshes and a large open area, for example a "Penta" type cloth, available from the firm Stork Brabant BV, Boxmeer, The Netherlands, or a "140 Topaz" canvas available from the firm Nickel Mesh Co Greer, South Carolina, USA Other canvas screens can also be used in the setting

  of the present invention Such screens include

  Typical screens have a mesh size of less than 0.77 mm and a thickness of about 0.060 mm for "Penta" or "Topaz" screens. A preferred screen for carrying out the present invention is a "140" screen. Topaz 'with a mesh size of 0.105 mm An inverted image 30 is applied to the screen of roller 26 by techniques

  screen preparation which consists primarily of

  cipally-coating the screen with a photopolymer emulsion

  riseable, to expose the emulsion through a positive mask of the image, to eliminate by the base the unexposed part of the emulsion and any excess of emulsion, then to make

  Dry the screen coated with the emulsion.

  In a preferred embodiment of the invention,

  [0005] This press is described in more detail in U.S. Patent Nos. 3,942,438, a rotary screen printing press of the "MW-RS" type, available from Johannes Zimmer, Klagenfurt, Austria. , 3,919,973, 3,921,520, 3,949,667 and 3,949,666. In this press, a magnetic scraper blade or magnetic scraper roller is placed inside the upper screen roller 26 and applies pressure on the ink being inside the screen to force it through the openings of the screen A magnetized lower roller 28 regulates the amplitude of the pressure applied by the scraper blade or the scraper roller However Other rotary presses may also be used in the practice of the present invention. Such presses are available from Precision Products Co, in Hawthorne, New Jersey, Buser Co,

Switzerland, and Reggiani Co, Italy.

  To print the opposite image, we can use

  common types of duplicating inks with alcohol.

  In general, a fluid hot melt ink is introduced inside the screen forming the roller 26 and is

  pushed back through the openings of the screen on the tape.

  The hot-melt ink contains a visible dye such as "crystal violet" type, a wax such as carnauba wax, spermaceti wax or candelilla wax, a wetting agent such as lecithin and one or more oils. such as mineral oil or 1.1

  In a variant, water-based inks are

  can also be used Alcohol duplicating dies can be printed on almost all types of paper, including coated and uncoated papers and treated and untreated papers. If a hot melt ink is used, the press is somewhat modified to include a heated ink supply tank. Heated air is introduced into the screen at a temperature (which can be between the ambient temperature and 4250 ° C and which is preferably about 290 ° C for the hot melt ink

  preferred alcohol duplication) sufficient to maintain

  Ink can be in the fluid state during printing. This air can be directed from the ink supply inlet to the printer.

the opposite end of the screen.

  Image-to-image alignment between the two

  printed sides of the strip is obtained by means of a

  the footprint alignment unit in the second printing station, as well as by conventional double-sided tape printing techniques, for example guides_

  In addition, the repeated lengths of the rolls of

  pressure in the printing stations 12 and 22 can be sized to be equal to each other and the

  part of the rotating screen carrying the image may be

  In the method of the invention, the tape executes a controlled and continuous movement, an alignment of the images can be obtained much more easily than in operations.

  previous discontinuous printing.

  The speeds of the rolls can be adjusted in the process so that the speed of the web is at most about 195 m / min.

  preferably about 60 m per minute.

  The rollers in the two printing stations 12 and 22 have conventional values for the respective types of printing operations performed, and they can also be varied conventionally according to the speed of the web, the temperature of the ink, the desired thickness for the image, etc. Once the strip 11 has been printed, it leaves the rotary screen printing press at an angle slightly higher than the horizontal, preferably between 0.5 and 6%, so that the printing gives

  satisfactory results A roller 31, placed immediately

  diatement downstream of the exit of the web between the rollers 28 and 30, gives the slight upward inclination which applies the ink more strongly to the web and

improves the quality of the image.

  The strip can then be cut into individual sheets, wound up to be subjected to other treatments, or it can then be processed as shown in Figure 1. An adhesive applicator 34 can be used to apply adhesive spots. 32 In order to glue a protective sheet 36 on the strip The protective sheet may come from a continuous roll 38 Alternatively, the protective sheet 36 may be glued on itself to the strip 11 In a station 40, the

  attached tapes can be punched and / or cut.

  A roll 42 can be used to cut or separate

  longitudinally the continuous bands and it can also

  perforations, if desired.

  Rollers 44a and 44b cut longitudinally

  strips -A knife 46 cuts the transverse strips

LEMENT.

  Figure 2 shows the preferred apparatus for

  continuous pressure on tape implementing the method of the invention As shown in FIG.

  strip 11 is debited from a roll 10 by means of a

  This device may be a "Schriber Model H-500" roll holder produced by Schriber Division, Harris Corporation, a "DG 175" roll holder from the firm Didde-Glasser, Inc., or any other equivalent means Band 11 is then

  driven by rollers 52 to a first position of im-

  The first printing station 12 may be, for example, an offset unit of the "Schriber Model H-500" type, an offset unit "D-G 175" or any other offset press. The strip 11, the first face of which is printed, is returned by the turning device 14 which has been described with reference to FIG. 1. After the strip has been turned over by the device 14, it passes into the rotary screen printing press. located in the second printing station 22 and with the help of which it is

  The ink used may be a thermo

  fuse that is solid at room temperature but becomes fluid when heated As described

  previously with reference to Figure 1, the thermofusil ink

  The fluid is forced through the upper screen roller 26 and printed on the web 11. When the web exits the printing station 22, the images formed by the ink

  hot melt cool and solidify.

  Once printed, the completed sheet may then be subjected to other operations as previously described. For example, an adhesive applicator 34 may be used to apply adhesive spots to a surface of the sheet, a protective sheet may be applied from a roll 38, and the continuous strip can be cut into individual sheets by a cutting device located in the station 40 and by means of a knife 46 drive rollers 48 and 50 adjust the speed of the All these operations can be performed by a sheet flow device of the type "Schriber Model H-500" or "DG 175" having a glue pump, a tape drive, a

  shear knife and a perforating device.

  The individual sheets can then be stacked on a stacking table 52 and then assembled, for example into a brochure of pre-printed dies.

  duplication with alcohol, if desired.

  It goes without saying that many modifications can be made to the described method and apparatus

  and shown without departing from the scope of the invention.

Claims (7)

  A method for the continuous production of pre-printed dies, characterized in that it comprises: a) advancing, from a roll (10), a continuous strip (11) of material to be printed on its first and second faces; b) passing the web into a first printing station (12) and printing images on said first face of the web during its continuous movement; c) the second face of the band being turned upwards, to pass the band in a second position   (22) print and print the inverted images of-   said images printed in step b) on said second face of the web, in alignment with the images printed on said first face of the web during   continuous movement of the latter, by means of a rotary press   screen printing unit having a screen roll (26) within the   where ink is introduced and forced to the ex-   interior, through said screen roller, to form said inverted images; and d) cutting the continuous strip into individual matrices on the first faces of which images are printed and on the second faces of which inverted images are printed, in exact alignment image   on image, with the images printed on the first side.   2 Process according to claim 1, characterized in that it consists in covering the first strip with a second strip (36) of material and adhering the strips one   to the other before the cutting operation.   3 Process according to claim 1, characterized in that the first face of the strip is printed by a offset printing process.   4 Process according to claim 1, characterized   in that the ink is selected from hot melt inks   and solvent-based inks.   Method according to claim 1, characterized   in that the ink is a hot melt ink.   Process according to Claim 5, characterized   in that the inside of the screen roller is heated.   Method according to claim 1, characterized in that the strip is held upwardly from the horizontal by an angle of between 0.50 and 6.00 between steps c) and d).   8 Process for the continuous production of pre-printed matrices, characterized in that it consists of: a) advancing, from a roll (10), a continuous web (11) of material having first and second faces;   (b) to move the band about   zontalally in a printing station (12) and print an inverted image on the upper face of the web   during the continuous movement, by means of a rotary press   screen printing unit having a screen roll (26) within the   wherein ink is introduced, this ink being forced out through the screen roll to form said inverted image; c) maintaining the strip so that it rises, relative to the horizontal, by an angle between 0.50 and 6.00, immediately after step b); and d) cutting said continuous strip into individual matrices. 9 Process according to claim 8, characterized in that   in that the ink is a hot melt ink.   Preprinted matrix sheet produced   by the method of claim 8. -.1