Sunday, July 31, 2022

Block printing (a fabric printing method)

 Block printing method:

·     This was the first printing method which was used to print fabric.

·     In this method, a block with raised printing surface is used.

·     The raised printing surface is inked with the desired colour first.

·     The inked printing surface is pressed on the fabric surface.

·     The desired design is completed after repetition of a single block according to design.

·     In old age, the blocks were made of terracotta.

·     Now, the blocks are made of carved wood.

·     The typical hand block print had no large, uniform areas of colour



·     It was skilfully built up from many small coloured areas because wooden surfaces larger than about 10 mm in width would not give an even print.

·     This had the advantage that a motif such as a flower would have an effect of light shade obtained from three or four blocks, each printing a different depth of the same colour or shade.

·     The bleached or dyed fabric is fixed upon the printing table first with the help of pins.

·     Now, the block is inked and the inked block is placed on the fabric surface and is pressed to make a colour impression to the fabric surface.

·     The number of blocks getting used depends upon the number of colours present in the design.

Various steps involved in the block printing method:

Various methods involved in the block printing methods are given below:

1- Carving of printing block.

2- Fabric mounting and fixing on the printing table.

3- Colours preparation.

4- Fabric printing.

5- Printed fabric drying.

6- Curing and finishing.

 

Carving of printing block:

 

Fairly hardwood is used for block preparation. The edges of the design do not break during fine cutting if the wood is fairly hard. The pear wood is much suitable for block making. The block-making process is completed in the below steps.

1- A flat wood piece of suitable size is selected as per the design including side margins.

2- The bottom and top surfaces of this wood piece are made plane and smooth with the hand plane tool.

3- Now, the bottom surface of this flat wool piece is rubbed with the help of sandpaper.

4- The rubbed surface of the wood piece is then coated with a removable white paint.

5- Now the required design is transferred upon this white-coated surface.

6- The design is carved upon the white coated surface with the help of cutting tools like fine and small chisels and drills.

7- The portion of the wood piece which appears as the unprinted area on the fabric is carved only.

8- The portion of the wood piece which appears as a printed area remains as a raised surface in the block.

9- Proper cleaning and finishing of the design of the block are done.

10-              Finally, each block required corner ‘pitch pins’ which printed small dots.

11-              These allowed the succeeding blocks to be correctly positioned by accurately locating the pitch pins above the already printed dots.

12-              A handle is fitted above this block to lift and press it during printing.

13-              The raised surface depth is kept at 10 millimetres and above.



Fabric mounting and fixing on the printing table:

1- A flat table is required for block printing.

2- The table width is kept according to the fabric width to be printed.

3- The width of the table is always kept more than the fabric width.

4- At least 6 inches margin on both sides of the width of the table is kept.

5- Cushioning on the table surface is done to make the table surface flexible.

6- Many layers of suitable fabric are spread over the printing surface of the table.

7- These fabric layers are fixed upon the table surface.

8- There should be no wrinkles on the cushion.

9- Now, the fabric is spread over the table.

10-              The fabric selvedge should be parallel to the length of the table.

11-              The wrinkles are removed from the fabric to be printed.

12-              The fabric is fixed upon the cushion with the help of steel pins.

13-              First of all, one side of the fabric is fixed upon the table in a straight line.

14-              Now, the other side of the fabric is fixed upon the table.

15-              There should be no wrinkles in the fabric after fixing.

16-              In this way, the fabric is ready for printing.

 

Colour preparation:

1- The required colour is prepared in the colour tray.

2-Different chemicals like binder, thickener, and softener are added to the colour as per recipes.

A separate colour tray is used for each colour.

4- A thick woollen cloth or thin sponge sheet is placed in the colour tray.

5-The woollen fabric or sponge sheet absorbs the colour well.

6-Now, our colour preparation process is completed.

Fabric printing process:

1- The fabric printing process begins according to the design.

2- Normally, light shade is printed first.

3- The block is gripped with the help of a handle fitted in it.

4- The printing surface of the block is touched to the woollen cloth or sponge placed in the colour tray and is pressed gently.

5-The printing surface of the block is picked up the colour well.

6- Now, this block is placed upon the fabric as per the design and pressed tightly.

7-The colour is transferred to the fabric surface now.

8-This block is repeated according to the design till completion.

9- Now, the second, third, and fourth blocks are taken in the required sequence and colours are printed on the fabric.




Printed fabric drying:

1- When the fabric printing is completed, the fabric is still in slightly wet condition.

2-If we remove this fabric from the table just after printing, the colour spots may have appeared upon the fabric.

3- We do not remove the fabric just after printing.

4-The fabric is left over on the printing table for few times.

5- The atmospheric air comes in contact with the printed fabric.

6-The moisture present in the fabric begins to evaporate now.

7- After some time, the fabric gets semi-dried.

8-Now, the possibility of the colour spot is finished there.

9- Finally, the fabric is removed from the printing table carefully and hung up on the ropes in the open place.

10-              The fabric comes with exposure to direct sunlight and gets dried completely.

 

Curing and finishing of fabric:

1- The colours of the above-printed fabric do not have enough fastness.

2-This fabric undergoes the curing process.

3- The fabric passes through the heating chamber for a definite time.

4-The crocking fastness of the fabric is improved after the curing process.

5- Finally, the softener is applied to the fabric to improve the touch and feel of the fabric.

6-Thus the printed fabric gets ready for use.

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PRE - TREATMENT PROCESS OF NATURAL CELLULOSIC FABRICS OR FABRIC PREPARATION FOR DYEING
CHEMICAL COMPOSITION OF COTTON FIBRE, CHEMICAL FORMULA OF COTTON FIBRE, CROSS SECTIONAL VIEW OF THE COTTON FIBRE


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