Application of Pigments
Application of pigments -
(i) Pigment dyeing process
(ii) Continuous dyeing with Pigment colours
Explanations -
Pigment-dyeing process
The simplest dying procedure does not have affinity issues. After being pigment-padded, dried, and cured or heated to solidify the substance. No post-treatment is required.
Pigments are often applied quickly and simply using simple standard tools and methods.
After application, the colours are dried so set by acid or steam ageing, curing in hot air at about 150°C, or both.
Contrarily, printing and dyeing with dyes frequently require extensive steam treatment, frequently at pressures greater than atmospheric.
After steaming, many dyes also need time-consuming wet processing, which raises the value of the application.
every kind of synthetic fibres, union or blended fabrics, and dyeing all of them may be done successfully with pigment colours.
Pigments hardly have any affinity for the fibres, and as a result, they do not tend to exhaust from the tub.
The dip-pad method may be accustomed apply pigments; a typical setup is depicted in the Figure below.
Because the concentration of the pad liquor doesn't fluctuate much during the padding process, it is easy to provide lots of pigment-dyed fabric with little fluctuation in hue from start to complete.
.jpeg "Application of pigments by dyeing process")
The danger of shade variation is far reduced compared to it normal dyes because no further chemical processing is required to come up with the shade.
The pigment-padded cloth must, however, be dried evenly to stop pigment migration, which happens easily when uneven drying occurs. small stuff materials are most suited to pigmented pad-dying because the unevenness is most obviously seen as face-to-back colour difference (i.e. one side of the material is lighter or darker than the opposite side).
Even the colouring of material composed of continuous filaments is tougher to realize.
The O/W method is usually employed for pad-dying. the subsequent ingredients compose the pad liquor: colour concentrate (pigment dispersion), binder, thermoplastic and thermosetting compositions emulsion, emulsifier, protecting colloid, and water.
The pad liquid must have enough protecting colloid and emulsifying and dispersing agents to stay the dispersion of pigments and resins over the range of typical dilutions.
In pigment dyeing, a padder, especially of the pneumatic or hydraulic variety, with a shallow pad box and two or three pad rolls, is usually employed because of the impregnating apparatus. the material is dried as soon because it has been impregnated, evenly drying each side. The plastic binder is ready and rendered insoluble by curing the material at 125–175 °C for 3–6 minutes after it's dried.
The kind of fibre being utilised yet because the resin binder getting used determine the suitable curing conditions.
Using swelling agents within the pad liquors is often required to attain appropriate fastness qualities across a spectrum of hydrophobic man-made fibres.
The binder, not the pigment, determines how easily the coloured fabric will wash. permanently absorbency to be created, an appropriate pretreatment is required.
The padding mangle and dryer should work well, as was previously described.
Only light hues and maybe some medium tones are feasible because most dark shades have insufficient rubbing fastness.
The pigment dyeing method is utilised mostly for low-cost characteristics and is fitted to all natural and manmade fibres.
If light pigment dyeings and pigment printing are used simultaneously, the padding that has already partially dried is primed before the dyeing and printing are fastened together.
The ColorChem Company, which sells pigment emulsions under the marque “Acram. ne," suggests the subsequent proportions for a pigment padding liquid for various shade depths (Table below).
The business also suggests a method for applying its pigment emulsions. The unique benefit is that the pigment dyestuff does not exhibit significant temperature-related migration.
Pigment emulsion (gpl) | Acramine binder emulsion (gpl) | Acetic acid (30%,in ml) | Ammonium chloride (gpl) |
0.1 to 1 | 20 | 3 | 2 |
1 to 2.5 | 25 | 3 | 2 |
2.5 to 5 | 30 | 3 | 3 |
5 to 7.5 | 40 | 3 | 3 |
7.5 to 10 | 50 | 3 | 3 |
10 to 15 | 60 | 3 | 3 |
15 to 20 | 80 | 3 | 3 |
Above 20 | 100 | 3 | 3 |
Question -
Explain the pigment dyeing process.
References
Hussain, T. (2014). Pigment Dyeing and Finishing of Cotton /Polyester Fabrics with a Modified Dihydroxyethyleneurea and various softener treatment. Life Science Journal. https://www.academia.edu/29522602/Pigment_Dyeing_and_Finishing_of_Cotton_Polyester_Fabrics_with_a_Modified_Dihydroxyethyleneurea_and_various_Softener_Treatment
Pigment dyed vs garment dyed: What’s the difference? (n.d.). Nyfifth.com. Retrieved 26 December 2022, from https://www.nyfifth.com/blog/2020/05/26/pigment-dyed-vs-garment-dyed-whats-the-difference/
Pigment Dyeing,Pigment Dyeing process,Pigment Dyeing Method,Pigment Dyed Garments,Pigment Dyed Clothing,pigment dyed fabric. (2011, February 10). Fibre2fashion.com; Fibre2Fashion. https://www.fibre2fashion.com/industry-article/5426/production-process-for-pigment-dyed-garment
ProductIP. (2021, March 8). Dyes and pigments. Productip.com. https://www.productip.com/kb/productipedia/compliance-resources/dyes-and-pigments
(N.d.). Researchgate.net. from https://www.researchgate.net/publication/260797037_Pigment_Dyeing_and_Finishing_of_Cotton_Polyester_Fabrics_with_a_Modified_Dihydroxyethyleneurea_and_various_Softener_Treatment
Part 2 Pigments - Properties and classification
Part 3 Pigment dyeing requirements
Part 4 Application of pigments by the dyeing process
Part 5 Advances Pigment dyeing
