Rope dyeing machine

Rope dyeing machine

• The rope dyeing process is the dyeing process of yarn in rope form.

• In this process, a ball beam of several warp threads is prepared. (This ball beam is a kind of warper beam with rope winding.) 

• The ball beam is made in ball making device.

• A rope of ball is made from 400-450 yarn threads with slightly twisted foam.

• Yarn is passed through a comb-like device known as a hack or reed for the separate and parallel arrangement of yarns with their neighbouring yarn.

• Basically, a small yarn sheet is passed through a funnel-shaped device known as a trumpet or condenser that transfers the yarn sheet into a rope.

• This rope is winding with a traverse from back to forth on the beam and creates a ball beam.

• 10-20 ball beams are arranged into creel and passed by the guide in such a way that all ropes are separate from each other.

Ball beam from rope

• Then these ball beams are going for the dyeing process.

• Before dying, the Rope sheet is first washed with chemicals such as caustic and washing soda in the pre-wetting box.

• This is basically the scouring process. (In this process, wetting agents and detergents are available in the souring bath, which removes the dust, ash, dirt, minerals and pectin, and Wax layer from the fibre surface.)

• After washing, the rope sheet passes through the squeezing process to remove the excess water from the rope sheet.

• The rope sheet is then able to absorb dye properly so it passes through the dyeing box.

• The rope sheet is dyed into the dye box, then goes for the oxidation process, and then again goes into another dye box.

• The concentration of Hydrosulphite is measured by a variometer. In the ideal case, It should be from 1.5 gpl to 2.5gpl, or by redox potential of the dye bath which should be from -730 mV to -860 mV. 2. 

• Caustic Soda or pH value Should be from 11.5-12.5 Effect of pH At pH of 10.5 to 11.5, there will be the formation of more mycophenolate ions, which leads to higher colour yield, as the strike rate of the dye to the yarn bundle is very high, and wash down activities will be perfect. At a pH higher than this, dye penetration will be less, and wash-down characteristics are also poor. 

Rope dying machine

• Repeatedly dying process is necessary because every dye tank adds some colour to yarn and greater the ring effect.

• The number of the above cycles or the number of dye boxes depends on the ring effect or how much dye the weaver wants to penetrate the yarn surface.

• After dyeing, the dyed rope sheet is washed again with fresh water two-three times and finally squeezed before allowing it to pass through drying cylinders. 

• The dyed rope sheet is then separated by each rope and collected into a separate can for each and every rope.

• In the can, ropes are arranged by a coiling mechanism.

• The dyed rope cans are then entered into the LCB room.

• LCB - Long Chain Beamer is a set of machines, that remove twist (Inserted at ball beam making process) from rope and convert rope into weaver beam by wind drop threads parallel to each other.

• LCB has a specific mechanism that removes twists from the rope and creates proper tension from warp beam distance, so that beam is properly made.

• Long-chain beamer machines have a Lower efficiency because the yarn breakage rate in these machines is higher.

• This machine is a manual operation, for the preparation of the warp beam.

• To create one warp beam, 3 to 4 rope cans are required for this machine.

• After the warp beam is prepared, it goes for the starching device for sizing. 

• After sizing, the sized warp beam goes for weaving for fabric formation.

• Then the woven Denim Fabrics go through various finishing processes consisting of brushing, singeing, washing, and impregnation for dressing and drying. 

• A company can adopt any of the methods for dyeing depending on the requirement. 

This method has the advantages over the slasher Dyeing Method:

• This technology has a higher penetration of dyeing.
• The technology is a proven one. 
• This method hasn’t a problem of centre to selvedge shade variation

However, This method is more expensive than the slasher dying system and it has lower efficiency due to higher processing time and end breakages.

Questions - 

1. What is rope dyeing?
2. What is a ball beam in rope dyeing?
3. What is long-chain beaming?
4. How rope dying is done?
5. How many steps are required to complete rope dyeing?
6. What are the advantages of rope dyeing?

References

Hakoo, A. (2021, May 9). Denim fabric weaving - the manufacturing process, methods, and technologies. Textile School. https://www.textileschool.com/6890/denim-weaving-manufacturing-methods-and-technologies/

Pipon, M. (2020, August 7). Manufacturing Process of denim garments. TEXTILE VALUE CHAIN. https://textilevaluechain.in/in-depth-analysis/articles/textile-articles/manufacturing-process-of-denim-garments/

Sarkar, P. (2017, June 4). Denim fabric manufacturing process –the learner’s guide. Blogger. https://www.onlineclothingstudy.com/2017/06/denim-fabric-manufacturing-process.html

Shaikat, N. M. (2018, September 17). Denim Manufacturing Process, Types and uses [updated]. ORDNUR. https://ordnur.com/jeans/what-is-denim/

Types of denim fabric used in garment manufacturing. (2015, August 1). Garments Merchandising. https://garmentsmerchandising.com/types-of-denim-fabric-used-in-garments-manufacturing/

What is Denim Fabric: Properties, How it's Made and Where. (2019, November 11). Sewport. https://sewport.com/fabrics-directory/denim-fabric

Wikipedia contributors. Denim. Wikipedia, The Free Encyclopedia. https://en.wikipedia.org/w/index.php?title=Denim&oldid=1127607695

(N.d.-a). Textilelearner.net. from https://textilelearner.net/denim-jeans-production-process/

(N.d.-b). Masterclass.com. https://www.masterclass.com/articles/what-is-denim-fabric-a-guide-to-the-history-of-denim

Further reading -

Part-1 Slasher dyeing machine

Part-2 Rope dyeing machine

Part-3 Sizing machine

Writer - DSPAT Team