Source: The Stitch Times


Abstract: The garments produced from woven fabrics have in creased many problems, and experience has shown that existing styles as developed for piece-dyed fabric cannot be just assembled from grey fabric and thrown into the dyeing machine, unless they have been engineered from the original design stage for garment dyeing. To obtain a high quality final Garment there should be a thorough coordination between fabric supplier, accessories supplier, garment manufacturer and garment processor.


Introduction


The recent surge in export of garments has created a challenging opportunity for the garment processing industry because of:


  • Short pipeline necessary for quick response.
  • Reduced losses from dyed fabric waste.
  • No subsequent shrinkage. Reduced inventory.
  • Lower energy, water and labour costs.
  • Ability to produce small batches.
  • Most importantly to produce uniformly dyed garments with no variations in shade of the different parts of the garment, which is a major problem for garment manufacturers using piece-dyed fabric because of sort-to-sort variations.


Structure of the Garment Dyeing and Finishing Sectors


1) Conventional Finishers

Traditional finishing plants that have adopted garment dyeing in addition to their conventional production.


2) Laundries/Dry Cleaners

These establishments do garment dyeing as an additional profitable activity to give a new lease of life to garments with no guarantees offered on the final appearance of fastness.


3) Garment Dyers

Composed of fully established fashioned dyers.


Quality Control in Garment Processing


The garments produced from woven fabrics have produced many problems, and experience has shown that existing styles as developed for piece-dyed fabric cannot be just assembled from grey fabric and thrown into the dyeing machine, unless they have been engineered from the original design stage for garment dyeing. Care should be taken that the grey fabrics dye-up identical in shade and if necessary must be adequately pretreated before dyeing.


The other major areas for control are: Seams, elasticated areas, waist bands, cuffs. Shrink behaviour, Chafe marks/creases, Accessories, Sewing thread, Foreign substances, Inter linings and Care labeling depending on the fastness requirement, being the most important of them all.


Elasticated areas, waist bands and cuffs, must be fairly slack, and seams should not be too tight or bulky, otherwise poor penetration of dyestuff occurs especially with heavy articles and heavily swelling fibres like cotton. However the problem can be solved by using suitable dyes and the right process control.


The use of a high application temperature dyes not only ensures that the migration potential is fully realized, it also offers several additionaI advantages. Higher temperatures mea ns better diffusion, better penetration and better running of the cloth facilitating liquor flow. These benefits assume particular significance in garment dyeing, especially in garments that have multilayered seams of woven fabrics (pockets, lapels, zips etc) or tight elasticated waists and ribs.


Thus a short period at high temperature i.e. 950C before cooling for fixation with reactive dyes has overcome even the most difficult seam penetration problems.


Shrink Behavoiur is important because of excessive shrinkage of the article or uneven shrinkage where knitted and woven fabric are mixed which leads to seam puckering, when it becomes important for pre-relax knitted fabric and the pre-treated woven fabric must be fully pre-shrunk by giving the various shrink-proofing treatment for high quality fabrics. To rule out the possibility of later complaint, it is advisable to carry out a blank dyeing.