Engraving Of Roller Printing

WE LCOME T O O UR GR OU P PR ESE NTATION

MEMBERS OF CITONE GROUP M. RUBEL RANA MD. SAIDUR RAHMAN MD. TARIKUL HASAN H. M. KHALED MURSHED MD.HABIBUR RAHMAN ZOBAYER RAHMAN

ID# ID# ID# ID# ID# ID#

042 056 041 042 096 041 042 099 041 042 040 041 041 008 041 041 023 041

ENGRAVEING OF THE PRINTED ROLLER

Engrave roller printing 

 



In this method, a heavy copper cylinder (roller) is engraved with the print design by carving the design into the copper. Copper is soft, so once the design is engraved, the roller is electroplated with chrome for durability. It is modern continuous printing technique developed in the late 19th and early 20th centuries. Until the development of rotary screen printing; it was the only continuous technique. The fine design detail possible with this technique has always been its main advantages.

The method of roller engraving Die and mill method  Pantograph method  Photographic method  By hand method Graphic 

Industrial

Process of Die and mill method    

 

At first the repeat of design is transferred to a small mild of steel roller, Then is called die. The top side of this roller is burnished. The circumference of the printing roller is must be proportional to the die. The burnished die is padded in solution of copper sulphate. Fe + CuSO4 → Cu + FeSO4 The design is art in the paper by the solution of sodium sulphite. Then the die is covered by the design paper.

Process of Die and mill method     

 

Then binding with tightly by canvas. This process is run continuously 1 to2 hrs. In this process is used bone ash and charcoal and heated. After this die is attached by the clamp at mild steel roller contact, then the steel roller is called mill. The die and mill is rotated at high pressure and the design is replaced in the mill. Then the pressure is removed. Thus the roller is engraved.

Figure: Die and mill method Where  

  

M=Mill B=Block S=Adjustable support F=Fulcrum R=Copper roller W=Weight

Engraving of copper roller 

In this method, a heavy copper cylinder (roller) is engraved with the print design by carving the design into the copper. copper is soft, so once the design is engraved, the roller is electroplated with chrome for durability.

Engraving of copper roller  Three o

o

o

different methods of engraving. By hand with a graver which cuts , in which the metal away. By etching the pattern is dissolved out in nitric acid; and By machine, in which he pattern is simply indented.

The defects in the engrave roller printing  Scratches  Snappers  Lifts  Streaks  Scumming  Lobbing

Scrimps These are caused by the creases of folds in the cloth. They are visible in the form of a double edge with white unprinted part left over in between, below a crease or a fold in the cloth. scrimp rollers at the back of the drying arrangement must be perfectly set right.

Uneven Printing This may be caused by several factors such as

   

Uneven pressure on the two ends of the design rollers which will show light and deep print in the selvedges. Uneven lapping of the furnishing rollers. Uneven addition of the colour at one end of the colour box. Greater percentage of insoluble substance in the paste. Uneven diameter of the design roller due to constant polishing of one end of the roller.

Types of scrapers  Metallic

scraper  Wood scraper  Rubber scraper  Hand scraper  Automatic scraper  Roller scraper  Flat scraper

Main parts of Roller printing  Color

doctor  Lint doctor  Blankets  Back grey  Furnishers  Color box / tray  Color unit

Figure: Roller printing

Figure:Nip of roller printing machine

Figure: Sectional view of roller printing m/c

Figure: Box wheel of roller printing m/c

Figure: Six color roller printing m/c

Advantages of engrave roller printing machine        

Higher production without rotary screen printing machine. 14 colors can be used for printing. Medium design can be produced. Can be used for printing any style. Any color is used for printing without higher alkali or conc. acid. Repeats do not exist as printing is continuous. Higher production by using single color. Complex design is possible.

Disadvantages of engrave roller printing machine  Large

design is not possible.  Generally, shedding fault is found.  Higher coloring effect is not possible as like block printing.  Lower production by using more than one color.  Changing time is high.  Engraving the printing roller is expensive operation.

Distinguish between the Copper roller and screen printing Parameters

Rotary Screen Printing

Copper Screen Printing

Design size

Generally 64cm

Upto 41cm

Colour

24 colour used

16 colour used

sharp line

Design is not impossible

Design is possible

Shade variation

No possibility

Possibility

Design change

Less time

More time

Printing

Woven and knitted fabric

Woven and tricot fabric

Main elements

Rotary screen

Engrave copper roller

Printing method

Higher used

Lower used