FR2641230A1 - METHOD, MATERIALS AND DEVICE FOR PRINTING HIGHLY COVERING SURFACES - Google Patents

Abstract

A method of printing with pigment printing systems containing fillers, in which at least one pigment printing system is printed on a support, by means of at least two pattern generators arranged one behind the other in time and space, and in which the support and the pattern generator are moved relative to each other, by a displacement device, characterized in that the printing system is brought into contact with a fluid, before the second pattern generator is reached in time and space, which fluid produces an at least translucent chemical skin around the printing system, and this in a much shorter period of time than the time required to reach the second pattern generator.

Description

In the textile industry Car example, but also for the printing of

  tapestries, papers, plastic sheeting or the like, there is the problem of printing very blanket. For example, there is a black material which must be printed with two different patterns of the same color. There is therefore a single printing system and two pattern generators arranged one behind the other in time and space, these pattern generators here having the form of screen printing screens. The pigment printing system containing a large quantity of fillers is for example in this case a pearl paste. silver effect. The two pattern generators therefore work with the same pigment printing system containing a large quantity of fillers and it is only possible to print here short printing films, "short" here meaning from a few tens of meters to for example 200 meters . Representative known print speeds are so many meters per minute. Since the pattern produced by the first screen cylinder must necessarily pass through the second screen cylinder, the following effects occur: a) We must work very slowly so that the first printing system can dry a little before

go through the second cylinder.

  b) Between the two cylinders,

  place dryers, which complicates the machine, the

  makes it costly and affects energy consumption

  gie. c) Drying changes the dimensions of the strip,

  so that afterwards you cannot print with precision.

  d) The driers radiate heat to the upstream cylinder and to the downstream cylinder. The frames therefore also heat up and the inks can dry and become blocked in the frames, since these inks are treated

  to form hot dandruff.

  e) The dough from the first cylinder remains

  partially attached to the second cylinder and

  then put in the fabric 11 where there should be no ink. The fabric is then either discarded or classified as second choice. f) The pattern printed by the first cylinder is pressed more and more into the fabric by the next cylinder, so that the pattern of the first cylinder is

paler.

  g) Where the second cylinder removes dough,

it is missing in the first motif.

  h) The cylinders must be frequently assembled and disassembled and cleaned. The necessary solvents are expensive and constitute a direct or indirect nuisance

for people and the environment.

  i) In particular for pearl pastes, metallic pigment printing pastes, varnish printing pastes, glossy printing pastes, etc., the small sheets producing these effects are increasingly pressed in the and there is no more left

  after the color but without the effect on the fabric.

  Currently, before applying a printing system for frame printing or screen printing, initial drying phases are taken into account, if

  this is printing on products by the meter, by printing

  classic manual printing, table printing with semi-automatic machines, as well as printing

  to the frame or serigraphy of cut pieces, prints

  manual and cylinder printing machines

  dre. With greater expenditure of time, material and ideas, it is possible here to prevent adhesion problems on the supports of pattern generators and on the

following pattern generators.

  For frame printing or screen printing, and

  this in the case of the printing of footage on machines

  nes for printing in the frame, and for printing in the frame or screen printing on parts cut by automatic carousel machines, we have the possibility of printing side by side in several colors of the systems

  pigment printing containing fillers, in particular

  especially pigment printing systems containing a large quantity of fillers, by the additional use

  silent intermediate dryers in the printing process

  if we. However, continuous printing operations for

  intaglio printing (roller printing

  leaux) and for rotary screen printing, do not allow the formation of a surface film by initial drying. For example, the accelerated adhesion of highly pigmented printing systems leads, if they are used several times in the wet printing process, to an adhesion effect on

the following printing groups.

  To the extent that these processes pose problems,

  mes, it is recommended to use the covering pigment printing systems (for example the pastes) only with a treatment instruction "in last hand". That is, a covering effect in the pattern can only be produced with the techniques of intaglio printing or rotary printing, only in a color position. If no report and reference constraints are prescribed (for example screen printing),

  if necessary several passages of machines for

  so these covering multi-effects.

  When it comes to printing printing systems

  multi-colored pigment covering, covering,

  nant loads, we are forced to resort to less profitable processes economically printing in the frame or screen printing with intermediate drying and short films. If the market demands multi-pigment printing systems containing fillers (for example applications of multi-covering pastes) they are often sent to table printing machines, in order to avoid losing prestige on the market. . If necessary, we

  uses the rotary printing technique which

  however, there is a loss, as described above - of products, dough, time, etc. In this printing technique, textiles are still an easy support. On the other hand, it is very difficult to print coated papers or papers treated with silicone, sheets of plastic material, etc. The object of the invention is to indicate a means concerning the process, the chemicals and the device, to prevent pigmentary printing systems containing fillers from adhering to the support of the following pattern generators and also to prevent the following pattern generator support overwrites the pigment printing system containing fillers, previously printed. However, high print speeds must be ensured and current technology

must be kept.

  For example, it should not be necessary to modify the principle of current methods. It should even be possible to be able to operate the existing machines according to the invention, with modifications of

  relatively reduced construction.

  This object is achieved according to the invention in that the printing system is brought into contact with a fluid, before the second pattern generator is reached in time and space, which fluid produces a chemical skin at least translucent around the printing system, and in a much shorter time than the time required to reach the

second pattern generator.

  Thanks to the invention, it is obtained that the printing system is not pressed (crushed) in the support and that it does not remain either stuck on the following pattern generator. This applies in particular when the printing systems are pearl inks, inks

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  with metallic pigments, lacquers, gloss ertres and among these in particular pearl pastes, metallic pigment printing pastes, lacquer printing pastes, glossy printing pastes or the like. It is not necessary to take into account the footage and you can print continuously. Since the skin forms very quickly (between a few tenths of a second and a few thousandths of a second), we can print at a corresponding speed. Printing speeds vary between 5 and 100 m / minute, preferably between 15 and 40 m / minute. It also avoids having to wash the pattern generators on which the

  printing systems stayed hooked.

  Pattern generators can be all available

  sitives known in this field, such as engraving cylinders, frames, screen screens, etc. The pattern generators can be applied to cylinders, carts or the like. By support used for printing is meant a cut textile piece or even a coated paper, a paper treated with silicone, a plastic sheet which can be a PVC sheet using one or more of the following methods: frame printing or screen printing; printing on products by the meter (classic manual printing, table printing with semi-automatic machines, frame printing machines);

  printing of cut parts (manual printing, automatic machines,

  carousel matics, cylinder printing machines); engravings

  intaglio (roller printing); rotary screen printing.

  Finally, it should be noted that the printing paste

  sion may be a foam paste containing parts which can be expanded by heat. The skin can also be produced by a reaction between biopolymers (xanthanes) and ions

  metallic with three or four valences.

  Various other characteristics of the invention come out

  Besides, try the detailed description which follows.

  A preferred embodiment of the invention is illustrated by way of nonlimiting example in the appended drawings, in which:

  Figure 1 is a side view of a printing machine

  rotary machine, Figure 2 is a schematic view of the operation of the rotary printing machine using the machine, Figure 3 is a schematic view of a second example

of achievement.

  The machine shown in Figure 1 is the im-

  rotary fabric pressure known commercially as

  Rotamac 4 generation from Fritz Buser AG of CH-3428 Wiler.

  This machine can be used for the invention without modification, but without the usual drying bars. Figure 1 shows the strand 11 of the fabric. In addition, an endless strip 12 is

  stretched between two return cylinders 13, 14. Leaving the strand

  edge of fabric 11, the support which is here a strip of fabric 16, moves flat on the endless belt 12, under the cylinders 17, 18, 19, 21, 22, 23, 24, 26. These are rotatably mounted at both ends and tc rnnent synchronously. They carry pattern generators in the form of frames and have pigment printing systems inside containing a large amount of fillers, in the form of paste. Unlike the more liquid printing system, pastes have the advantage of having a contour that stays sharp, because they do not drip on textiles and other absorbent materials. There are doughs from different manufacturers. The applicant produces pearl pastes known commercially under the following designation TUBIRPEL, metallic pigment printing pastes known commercially under the following designation TUBISCREEN, MCR, lacquer printing pastes known commercially under the following designation TUBILAC and glossy printing pastes known commercially under the following designation Tubi-Screen GL. In

  the cylinders, the usual doctor blades 27, 28, 29 are shown, etc.

  which are used at the same time to supply the printing system

pigment containing fillers.

  According to Figure 2, the fabric 16 moves from left to right. In the cylinder 17, the doctor blade 27 is provided. The cylinder 17 has an opening 31 which is covered by a screen 32 generating patterns. The doctor blade 27 is fixed and the cylinder 17 moves in the direction of the arrow 35. To the left of the doctor blade 27 is a glossy printing paste 33. At each rotation,

26 4 1230

  glossy printing paste comes out of screen 32 depending on the

  pattern. Three similar patterns 34, 36, 37 are deposited on the fabric web.

  su 16. Contrary to the shortened view shown, the distance from one pattern to another corresponds to a perimeter of the cylinder 17. The patterns 34, 36, 37 are not dried. On the contrary, they arrive wet at the cylinder 18. The latter rotates exactly synchronously with the cylinder 17 and has the same perimeter as the latter. It also has an opening 38, the perimeter of which is however greater than that of the opening 31. Its opening is also covered by a

  screen 39. The opening 38 arrives, during the process, always exact

  on the grounds 34,36,37. In the cylinder 18, 1 a doctor blade 28 scrapes a substance 41 which contains a two-valence and / or three-valence metal salt, based on magnesium and / or calcium and / or aluminum. To the glossy printing paste 33, an alginate compound was added. The skin 42 is instantly formed on the skin 43 which is smooth and transparent, which does not destroy the glossy printing effect. It is also very thin and does not form thick deposits. So that on the edges, the opening 38 is not obstructed, it is large enough not to touch the front edge and the rear edge of the pattern 42, because otherwise the reaction between

  the alginate and the metal salt would block the opening 38.

  The cylinder 19 is only shown schematically.

  Its construction is similar to that of cylinder 17.But its opening

  ture is angularly in another place, unless one wants to print precisely on the patterns produced by the cylinder 17. The patterns are not pressed (crushed) by the cylinder 19 in the fabric 16, and they do not also do not stay stuck on the perimeter

  of cylinder 19. On the contrary, they pass through cylinder 19 without dom-

  The skin 43 has self-healing properties. Even if, for example, the pressure of cylinder 19 caused the skin to burst 43.1e

  small hole or the crack would close instantly and the

  sance would be minimal. Obviously enough alginate and

  of metal salt so that the reaction can take place in two

  xth or even a third time.

  Whatever the number of cylinders following the cylinder 17,1a gloss printing paste is visible on the fabric strip 16 until the end, without losing its quality. This is despite the fact that the relatively large gloss flakes tend to stick, by adhesion, to the periphery of the cylinders, some of which

are very smooth.

  However, according to FIG. 3, the metal salts can also be applied over the entire width of the strip 16, by an applicator 44. The strip of fabric 16 is thus impregnated with a layer 46 of metallic salts. The cylinder 17 therefore deposits its pattern 34 which contains an alginate compound, in the layer 46 and the reaction described above then takes place. The following cylinders 47, 48 can be of the cylinder type 17, i.e. they can apply

  pigment printing systems containing charcoal

  ges. Typically, it used to take a day and a half to print a length of 800 m. We printed footage of 30 m, we washed the pattern generators, we reassembled them after having dried them, at the beginning of printing, we always accepted

  scrap and we printed again 30 m.

  In a test according to the invention, 1100 m were printed in one hour, without interruption, which corresponds

  at a speed of 20 m / minute as a production speed.

  We completely removed the disassembly, washing, drying and reassembly of the pattern generators, there

  also has no scrap on the first meters.

  With the invention, one can certainly achieve m / minute. To give an idea of the order of magnitude: the machines for printing linings, in a single color, print about 60 m / minute; at this speed, however, you can no longer control the quality of the fabric. It has been found that the skin 43 is formed at least during the time necessary for the support 12 to pass through two printing stations with a ratio of 64 (perimeter of the frame 64 cm). This represents at 80 m / minute, 0.48 second, at 40 m / minute, about 1 second and at

m / minute, about 2 seconds.

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  A preferred embodiment of the invention will be cited below: A. "Brilliant pearl paste" which can form a skin made up of approximately 50% of binder (dispersion binder based on polybutyl acrylate) approximately 10 to 15% of filler = shiny pearl pigment, known commercially under the name of Iriodix from the company Merck 0 to 5% of pigment dye 0 to 2% of cross-linking agent (melamine resin type) 0 to 2% of plasticizer 0 to 1 Z emulsifier 0 to 2% dispersant

  1 to 2 Z of thickener = sodium alginate type (2% corres-

  lays at 5000-7000 mPas) 0.1 to 0.2% anti-foaming agent (polysiloxane) 0 to 0.5 Z of acidifier and water Viscosity of the paste: 3000 to 4000 mPas (pH adjustment : depending on the type of binder)

  B. Paste for overprinting with "form chemicals

  mation of a skin "0.1 Z of anti-foaming agent (polysiloxane) 4 to 8% of calcium chloride 1.5 to 2.5 Z of hydroxethylcellulose (added at a rate of 2% to H2O, approximately 3500 at 4500 mPas) 0.05 Z of ammonia for pH correction, the rest being 100% water

  Viscosity of the dough: 3000 mPas - pH: greater than 8.

  As general indications, it is mentioned as entering into the printing process, the use of polygalactomannans, base compounds which can form a gel, active anion compounds, active cation compounds, borax compounds , from

264 1230

  composed of guar, biopolymers (xanthans), flour

carob, carragheen.

  (s ": 2641230 of cations or a substance containing polyvalent metal ions. 9. Method according to claim 8, characterized in that the compound is an alginate compound and the substance a polyvalent metal salt. 10. Method according to claim 9, characterized

  in that the metal salt is A two or three valences.

  11. The method of claim 10, charac-

  terized in that it is magnesium salt and / or salt

  calcium and / or aluminum salt.

  12. Method according to claim 1, characterized in that the printing system on the one hand and the fluid

  on the other hand, alternately contain polygalac-

  tomannans or boron compounds which can form a gel,

in an alkaline medium.

  13. Method according to claim 1, characterized in that the printing system on the one hand and the fluid on the other hand comprise compounds alternately

  active anions or active cation compounds.

  14. The method of claim 12, charac-

  terized in that polygalactomannans are compounds

borax and / or guar.

  15. Method according to claim 1, characterized in that the skin is produced by a reaction between

  biopolymers (xanthans) and carob flour.

  16. Method according to claim 1, characterized in that the skin is produced by carragheen / calcium and potassium ions on the one hand and carob flour

on the other hand.

  17. Method according to claim 1, characterized

  in that a transparent skin is produced.

  18. Method according to claim 1, characterized

  in that the skin is self-healing.

  19. The method of claim 1, characterized in that one prints with several pattern generators

  and that each pattern generator brings a color.

  20. Method according to claim 1, characterized

  in that the pattern generators are frames.

  21. Method according to claim 1, characterized

  in that the pattern generators are engravings.

  22. Method according to claim 1, characterized

  in that the support is a cut piece.

  23. The method of claim 22, character-

  se in that the cut piece is a textile piece.

  24. Method according to claim 1, characterized

in that the support is a strip.

  25. The method of claim 24, character-

  se in that the strip is a textile strip.

  26. Method according to claim 1, characterized

  in that the support is a coated paper.

  27. Method according to claim 1, characterized

  in that the support is a paper treated with silicone.

  28. Method according to claim 1, characterized

  in that the support is a plastic sheet.

  29. Method according to claim 28, charac-

  terized in that the sheet is a PVC sheet.

  30. The method of claim 1, characterized in that one or more of the following methods are used: frame printing or screen printing; print on

  products by the meter (classic manual printing, printing

  table with semi-automatic machines, frame printing machines); printing of cut pieces (manual printing, automatic machines% carousel, printing machines With cylinders); intaglio prints

  (roller printing); rotary screen printing.

  31. Materials for the formation of a chemical skin

  that created in the process according to one of the claims

  previous. 32. Device for implementing the method according to

  one of the preceding claims.

  33. Method according to claim 3, characterized in that the printing paste is a foam paste

  containing heat expandable parts.

  34. The method of claim 1, characterized in that the skin is produced by a reaction between biopolymers (xanthanes) and% three metal ions

or four valences.