This document provides information about stock dyeing, which involves dyeing staple fibers before spinning. It discusses the old and new methods of stock dyeing, including removing packed fiber from bales and dyeing entire bales. The document also describes the machinery used, including conical pan machines, pear shape machines, and radial flow machines. It notes the advantages of stock dyeing include an even color throughout the fabric and resistance to rubbing, but it is the most expensive dyeing method.

1. Dyeing & Printing
Presentation
on
Stock Dyeing
Submitted to : Ms. Ettishri Rajput Submitted by : Ajay Gayakwar
Bittu Singh
Radhe Kumar
Shubham Singh

2. Stock Dyeing
Dyeing a staple fibre before it is spun
500-3000 pounds of fibre are dyed at a time
Methods :
a. Old – removing packed fiber from bales packing the stock in large vats
circulating dye liquor through the mass of fiber at elevated temperatures
b. New – Bale Dyeing – applicable to Wool & all types of man-made fibres
Splitting the bale covering on all six sides placing the entire bale in
machine along with the covering & straps forcing dye liquor through
the bale
- saves time and costs

3. Stock Dyeing
Overall even colour is obtained
Stock-dyed fiber doesn’t spins as readily as undyed fiber – loses some of its
flexibility – lubricants added in final rinsing overcome most of this problem
Woolens – often stock dyed
Expression “dyed in the wool” – attributes the quality of thoroughness
Uses – Oxford suitings, Tweed homespuns or Heather effect materials in which
delicate shadings of colours are produced by combining fibres of various colours
Tweed fabric Staple fiber packed onto a carrier being placed into a vat

4. Machinery & Technique
Types :
• Conical pan machine – fibre packed into a removable fibre carrier
- fibre carrier – located on a central spigot in the base of the vessel
- liquor circulation provided by an external pump
- pipework allows liquor to be circulated either from the base or the
top

5. Machinery & Technique
• Pear shape machine – removable perforated base plate through which liquor is
circulated via an impeller
- fibre is loaded directly – a perforated plate is positioned
on top
- liquor circulation packs fibre between the two plates
- unloading – plates removed by cranes & fibre manually
• Radial flow – a fibre carrier equipped with a central perforated column
- column – liquor flows across the pack to walls of the carrier

6. Machinery & Technique
Loose fibre – usually packed manually – capacity varies between 200-300 kgs
Working volume equivalent – 7 to 10 litres per kg fibre
Machines – low packing density – liquor circulates freely through fibre ar modest
pressure – minimizes mechanical damage to fibre
Bath – heated by closed steam coils in the base of the machine – temperature
may be controlled by a steam valve
Electro/Pneumatic programs or Logic controllers – regulate time/temperature or
control direction of liquor circulation
Liquor ratio – varies between 1:4 to 1:12 – depends on type of machine/fibre

7. Latest Modifications
Earlier – machines made of wood – dyes and chemicals were retained by them
affecting successive processes
Now – machines made of stainless steel
Automation :
• Operations such as machine filling, rise of temperature, circulation of liquor or
material, holding time, cooling time, draining
• Controlled using sensors, actuated valves, sequence controller, micro-processor
Benefits of automation :
• Reduced waste of materials, reduced dead time, improved shades, exact record
of consumption

8. Advantages
Excellent penetration of dye in the fabric & evenness of colour throughout
Effects such as Heather effect may be obtained
Dye penetrates core of the fibre – resists rubbing – high colour fastness
Disadvantages
Most costly method for dyeing
Low yield
10-15% of dyed fabrics are wasted through manufacturing steps
Not used for Worsted yarns – combing process removes short fibres – leads to
waste of resources

9. References
a) Shenai V. A. Technology of Dyeing, Volume VI. Pages 83-90. Bombay. 1980.
b) Corbman B. P. Textiles : Fiber to Fabric. Pages 212-213. Singapore. 1983.
c) Choudhury A. K. Textile Preparation & Dyeing. Pages 407-408. Retrieved from :
https://books.google.co.in/books?id=0TamObsaaPQC&pg=PA402&dq=loose+st
ock+dyeing+machine&hl=en&sa=X&ved=0ahUKEwj9pu24k4TPAhUIQY8KHaAzD
NEQ6AEINTAA#v=onepage&q=loose%20stock%20dyeing%20machine&f=false
d) Ministry of Environment & Energy, France. Wet Processes : Machinery &
Techniques. 2000 . Retrieved from :
http://ied.ineris.fr/sites/default/interactive/bref_text/breftext/anglais/bref/BR
EF_tex_gb54.html

10. Thank You!