Dyeing machineries

Dec. 13, 2018

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Dyeing machineries

  2. • Dyeing of textile material is carried out in various forms – Loose fibre stock – Yarn • Hank • Cheese • Cone • Warp – Cloth • Woven • Knitted – Garments • The dyeing of different forms required different kind of machineries – Because the method of handling of different material would be different during dyeing
  3. • The methods of dyeing can also be classified as – Batchwise – Semi-continuous – Continuous
  4. • Batchwise process – This method uses large amount of water (i.e. high M:L ratio) – The goods are immersed in the dye solution for longer time to let the dye molecules to penetrate inside the goods – Fibre, Yarn, Fabric and Garments are dyed in this process – Advantage: inexpensive, no need to train the worker to look after and run them properly – Disadvantage: Slow process, large amount of water is required
  5. • Continuous process – This method is designed by putting different machinery into a sequence so that fabric can be dyed in one pass – Mostly fabric are dyed in continuous process. Garments are not dyed in continuous process – Advantage: Very fast process, small amount of water is required – Disadvantage: Very expensive, need to train the worker properly to run the process
  6. The basic requirements of dyeing machineries – It should provide sufficient liquor movement for uniform dyeing – There should be uniform heating throughout the liquor – There should be some means of adding of dyestuff and chemicals that it mixes the bulk liquor before coming in contact with the goods to be dyed – The material of the machinery should not be affected by the dye or other chemicals required for dyeing
  7. • Material of construction of dyeing machines – The materials used in construction of dyeing machine should not affected by the chemicals used during dyeing – The dye and the chemicals used for the dyeing should not also affected by the material of which the machine is made – Usually chemical resistant stainless steel containing high quantities of chromium, nickel, tungsten and a small quantity of carbon is used for construction of dyeing machines
  9. MASS COLOURATION • This method is to dye the molten polymers with pigment dyes • After that the molten dyed polymer will be extruded from the spinneret to form filament / fibres • Normally, the synthetic fibres are added with white pigment in order to give a hiding power ( non-see through fabrics) • Advantage: Excellent fastness, no effluent treatment required
  10. Loose Stock Dyeing Machine • The fibres are pressed into a cake into a perforated suitable casing in a vertical closed vessel •The close vessel is filled with the dye liquor and the casing with the fibre stock is immersed in the dye liquor •The dye liquor is made to flow / circulate through the casing •The circulation of the liquor is reversed periodically to get an even dyeing •The machine includes a built-in reversible axial pump capable of change in rotation •Dyeing can be done up to 1000C
  12. HANK YARN DYEING MACHINE • It is a large stainless steel tank provided with water inlet and outlet •Provision is made to heat the dye liquor •The tank contains the dye liquor and the yarn hanks are suspended on flat stainless steel rods •The hanks are rotated periodically manually •Advantage: Low cost, do not require trained labour •Disadvantage: Chance of uneven dyeing due to temperature variation in the bath; chance of the dyed material to get exposed during dyeing (problem during vat dyeing)
  13. PACKAGE DYEING MACHINE •Yarns are dyed in packages like in the form of cheese, cone etc. •It consists of a vertical closed vessel having several perforated tubes •The soft packages are arranged one above the other on these perforated tubes •By means of a liquor pump, the liquor to be circulated is withdrawn from the outer container and forced up the tubes and, outwardly through the yarn packages and back into the outer liquor container (inside –out) •The direction of the flow of the liquor can be reversed automatically from time to time (outside – in) •The M:L ratio is kept around 1:10
  15. JIGGER •A V-shaped stainless steel vessel containing dye liquor •Have a pair of upper guide roll, an immersion roll and two draw rolls to pull the fabric through the dye liquor •The liquor is heated with the help of a steam pipe at the bottom of the jigger •The fabric has been drawn from one roller to another roller for several cycle until sufficient dyeing takes place •The forward and backward travel of the fabric enables it to pick up more and more dye liquor •After dyeing is over the dye liquor is run out from the vessel and filled with cold water for rinsing •The fabric is dyed in open width form •The M:L ratio in a jigger is usually about 1:5 or less
  16. WINCH •Winch consists of a vessel that has a curved back •Over the top of the vessel it has a elliptical winch rotated individually by electrical motor •The steam and chemical inlets are also located in this chamber •Textile materials are usually dyed in rope form in a winch machine •Mainly delicate textile fabrics are dyed in winch as the fabric is rotated with minimum tension •The winch is the prime mover of the fabric which is piled inside the dye liquor for adequate time •The desired M:L ratio is 1:20 to 1:40
  17. JET DYEING MACHINE •Both the fabric as well as the liquor are made to move •The liquid is forced through a narrow jet which pulls the fabric along and transport it through the jet at great speed •The fabric is dyed in rope form •The M:L ratio is lower •The machine consists of a main dyeing vessel, which stores the fabric and the dye liquor, a jet, a heat exchanger, a circular pump and a cloth reel •The fabric is in the form of endless loop and is carried with the help of the jet •Fabric with low dimensional stability should be avoided dyeing in jet dyeing machine
  18. PADDING MANGLE • Padding Mangle is an open width machine that can be used for continuous open width or batch-wise treatment of fabric •Mostly used for continuous or semi-continuous method of dyeing •Consists of a small trough to contain the padding liquor and a pair of ‘bowls’ to squeeze the liquor from the fabric •One roller is soft roller and the other is relatively harder •In padding mangle the fabric is impregnated into the dye liquor in the trough and the excess liquor is squeezed out by the padder •Here only the fabric is made to move through the liquor
  19. BEAM DYEING MACHINE • Consists of a large diameter perforated beam that can be introduced in an autoclave •The fabric to be dyed is wound on the perforated beam which is then moved into the pressure vessel •The machine is provide with reversible flow system i.e. inside –out and outside – in •The dye liquor is forced with the help of an effective pump through the fabric wound on the fabric •The dye liquor enclosed in a closed system passed through a heat exchanger before being pumped through the fabric •There is option to maintain high temperature and high pressure to enhance the rate of dyeing •This is a HTHP dyeing machine
  20. Beam Dyeing Machine • It is a HTHP dyeing machine • Time of dyeing is short • Dyestuff exhaustion from the dye bath is high • Level dyeing is obtained Jigger Dyeing Machine • It is not a HTHP dyeing machine • More time is required for dyeing • Low exhaustion • Levelness is moderate
  21. Beam Dyeing Machine • Requires long M:L ratio (1:20) • Production rate relatively lower • Damage of fabric is minimum • Delicate fabric can be dyed • Capital investment is lower Jet Dyeing Machine • Requires short M:L ratio (1:10) • Production rate is higher than Beam dyeing machine • Delicate fabrics should be avoided • Capital investment and maintenance is relatively higher