Roller printing

 -:Roller printing on textile:-



Roller printing:-

Also called cylinder printing or machine printing, on fabrics is a textile printing process patented by thomas bell of Scotland in 1783 in an attempt to reduce the cost of the earlier copperplate printing. This method was used in Lancashire fabric mills to produce cotton dress fabrics from the 1790s, most often reproducing small monochrome patterns characterized by striped motifs and tiny dotted patterns called machine grounds.

  1. Improvements in the technology resulted in more elaborate roller prints in bright, rich colours from the 1820s; turkey red and chrome yellow were particularly popular.
  2. Roller printing supplanted the older woodblock printing on textiles in industrialized countries until it was resurrected for textiles by william marrise in the mid - 19th century.

Contents:-

  • Engraved copperplate printing 
  • Bell's patent
  • Roller printing machines
  • Engraving of copper rollers
  • See also 
  • Notes 
  • Reference

-: Engraved copperplate printing:-

The printing of textiles from engraved copperplates was first practiced by bell in 1770. It was entirely obsolete, as an industry, in England, by the end of the 19th century. The presses first used were of the ordinary letterpress type, the engraved; plate being fixed in the place of the type. In later improvements the well - known cylinder press was employed; the plate was inked mechnically and cleaned off by passing under a sharp blade of steel; and the cloth, instead of being laid on the plate, was passed round the pressure cylinder. The plate was raised in to frictional contact with the cylinder and in passing under it transferred its ink to the cloth. The great difficulty in plate printing was to make the various impressions join up exactly; and as this could never be done with any certainty, the process was eventually confineed to patterns complate in one repeat, such as hand kerchiefs, or those made up of widely seporated objects in which no repeat is visible, like for instance,patterns composed of little sprays, spots, etc. Larger machines printing from two to sixteen colours are precisely similar in principle to the above, but differ some what,in detail and are naturally more complex and difficult to operate. In a twelve colour machine, for example,twelve copper rollers, each carrying one portion of the design are arranged round a central pressure cylinder, or bowl, common to all,and each roller is driven by a common driving wheel called the crawn wheel actuated, in most cases, by its own steam - engine or motar another difference is that the adjustment of pressure is transferred from the cylinder to the rollers which works in specially constructed bearings capable of the following movements capable of the following movements.


  1. Of being screwed up bodily until the rollers are lightly pressed against the central bowl;
  2. Of being moved to and from side ways - so that the rollers may he laterally adjusted; and 
  3. Of being moved up or down for the purpose of adjusting the rollers in vertical direction. Not with standing the great latitude of movement thus provided each roller is furnished with a box wheel, which serves the double purpose of connecting or gearing it to the driving wheel, and of affording a fine adjustment, each roller is further furnished with its own colour - box and doctors.
  4. With all these delicate equipments at his command a machine printer is enabled to fit all the various parts of the most complicated patterns with an ease, dispatch and precision, which are remarkable considering the complexity and size of the machine.
  5. In recent years many improvements have been made in printing machines and many additions made to their already wonderful capacities. Chief amongst these are those embodied in the intermittent and the duplex machines. In the former any or all of the rollers may be moved out of contact with the cylinder at will, and at certain intervals. Such machines are used in the printing of shawls and sarries for the Indian market. Such goods require a wide border right across their width at varying distances sometimes every three yards, sometimes every nine yards and it is to effect this, with rollers of ordinary dimensions, that intermittent machines are used. The body of the sarrie will be printed, say for six yards with eight rollers; these them drop away from the cloth and others, which have up to then been out of action, immediately fall in to contact and print a border or crossbar, say one yard wide, across the piece; they then recede from the cloth and the first eight again return and print another six yards, and so on continually.
  6. The duplex or reversible machine derives its  name from the fact that it prints both sides of the cloth. It consists really of two ordinary machines so combined that when the cloth passes, fully printed on one side from the first, its plain side is exposed to the rollers of the second, which print an exact duplicate of the first impression upon it in such a way that both printings coincide. A pin pushed through the face of the cloth ought to protrude through the corresponding part of the design printed on the back if the two patterns are in good fit.
  7. The advantages possessed by roller printing over all other processes are mainly three firstly, its high productivity, 10,000 to 12,000 yards being commonly printed in one day of ten hours by a single - colour machine; secondly, by its capacity of being applied to the reproduction of every style of design, ranging from the fine delicate lines of copperplate engraving and the small repeats and limited colours of the perrotine to the broadest effects of block printing and to patterns varying in repeat from I to 80 in, and thirdly, the wonderful exactitude with which each portion of an elaborate multicolour pattern can be fitted in to its proper place, and the entire absence of faulty joints at its points of repetition consideration of the utmost importance in fine delicate work where such a blur would utterly destroy the effect.

Engraving of copper rollers:-

The engraving of copper rollers is one of the most important branches of textile printing and on its perfection of execution depends, in great measure, the ultimate success of the designs. Roughly speaking, the operation of engraving is performed by three different methods, viz.

  1. By hand with a graver which cuts the metal away;
  2. By etching in which the pattern is dissolved out in nitric acid;
  3. By machine, in which the pattern is simply indented.

The end....




Written by:- Rashmi Jadaun.

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