Textile Dyeing: History, Modern Methods, and Color Fastness

• Color is a visual element, its intensity, depth, and reflection are important in textile design
• Fabric dyeing and printing are methods used to apply color to textiles

History of Dyeing

• Dyeing textiles using plant and animal substances dates back to the beginning of civilization
• Indigo dye, from the leaf of Indigifera tinctorial, was used in Asia as early as 3000 BCE
• Tyrian purple dye, derived from shellfish, was a highly prized and expensive dye
• Cochineal dye, derived from the cochineal beetle on cactus plants, was cultivated in Mexico and produces reds and purples using mordants

Modern Dyeing

• Most dyes and pigments in the 21st century are synthetic, deriving from coal or petroleum-based organic compounds
• Textile manufacturers recognize that consumers want the right color, but are irritated when a garment's color isn't maintained
• Colour Fastness refers to maintaining a garments color for an anticipated like
• 'Designed to fade' is on labels

Health and Safety

• Chemicals used in dyeing and printing must be handled with care, following the manufacturer's instructions
• Safe practices include:
  • Wearing rubber gloves and protective clothing
  • Avoiding inhalation of dust and vapors
  • No consuming of food in the work area
  • Storing dyes and chemicals properly
  • When mixing dyes and water always add the dye to the water, not vice versa
  • Working in ventilated areas
  • Using dedicated containers/equipment
  • Disposing of dyes carefully, considering environmental hazards

Printing

• Pigment is an insoluble colored substance applied to the surface of a material, usually with a binding material
• Printing paste is typically viscous
• Printing is a textile art to impart a surface design and allows for greater flexibility in coloring patterns
• Printed designs can be the basis for embroidery
• Multi-colored patterns can be used and applied to yarns, fabrics, or finished products

Principles of Printing

• Common basic principles include:
• Prepare a printing bed with a soft resist under a hard surface
• Apply viscous printing paste to raised surface of a print tool
• Press the print tool firmly onto the fabric, sometimes using a rubber mallet
• Repeat printed design, aligning the print is known as registration
• Heat-set printed fabric via steaming/ironing for print paste to penetrate fibers
• Washing printed fabrics after removes debris, residue or unfixed color

Direct Printing

• Direct printing commonly prints the design directly onto a textile's surface at fabric or yarn stage
• Types of direct printing include block, roller and warp printing

Block Printing

• Block printing is a method used to print patterns using blocks made of potato, wood, foam, metal, or lino
• Designs are hand-carved and unique, but Block Printing and aligning can be slow and difficult
• Most block prints are mono-color, but one can add more colours if necessary

Roller Printing

• Roller printing enables multicolor printing and is mechanized
• It is a cheaper method than block printing as it is less labor-intensive and produces large quantities of fabric
• Rollers are engraved or etched to repeat designs and roll onto fabric
• Up to 16 colors can be used, the rollers collect a color then transfer it onto the etched roller
• A small blade and the role of the blanket ensure a sharp print, then printed directly onto the fabric One method involves printing color onto paper, then transferring it to fabric via sublimation printing

Warp Printing

• Warp printing prints designs onto warped yarns before weaving them with plain weft yarns
• This create fabrics with soft, blurry, and muted-tone designs

Resist Printing

• Resist printing uses a resist to prevent printing paste from being applied to the fabric
• Includes batik, stencil, screen, and Ikat printing

Batik

• Batik uses Wax as a printing medium, stamping with a tjap, or drawing on the fabric with a tjanting.
• Dyeing and wax application is repeated several times for different colors
• After dyeing, the wax is scoured from cloth
• Requires planning designs carefully, Batik is labour intensive

Stencil Printing

• Uses a resist like acetate, plastic, tape, designs cut into sticky paper, stencil brushes or sponges applying printing paste and color

Hand or Manual Screen Printing

• Screen printing evolved from stenciling
• It can be done by hand or machine
• Hand screen printing requires skills in registration with different colors
• One screen for each color
• Screen put on printing bed, squeegee presses printing paste through design areas on mesh
• Screen picked up, reposition for next print

Machine or Flat-Bed Screen Printing

• Screen printing can be completed with machinery
• Silk, nylon or polyester screens are coated with a photosensitive emulsion
• The emulsion acts as a sealer to prevent paste from coming through screen
• Photographic plates are an emulsion acting as sealer, then placed on the screen, exposed to light, creating a chemical reaction so the design is visible

Colour Alignment

• The fabric is placed on a conveyor belt with flat screens above and lowered
• Placement of screens aligns print
• Small color blocks along the selvedge aids
• Printing paste forced, design printed
• Process is repeated for each colour in the design
• The Fabric fabric is also moved along conveyor belt to be heat-set/ cured in drying ovens
• Flat-bed screen printing is used for wide fabrics

Rotary Screen Printing

• Mechanized rotary screen printer is continuous production
• Rotary screen printing uses cylindrical screens, printing paste forced inside Cheaper to produce than copper rollers in roller printing

Ikat Resist Printing

• Ikat binds yarns at intervals along the length
• The design is printed or painted onto surface using dyes
• Can be warp, weft or both yarns ("double ikat" requiring careful planning and designing)
• Binding removed and the yarns woven into fabrics with blurred or fuzzy edges

Heat Transfer Printing

• It requires specially printed paper with designs heated at high temperature and pressure used to transfer design to fabric
• Sublimation: Dye changes solid to gas without passing liquid for textile fabric to not wet out
• Paper has design printed on it with disperse dyes, placed on fabric, passed through pressure-heated rollers
• Dyes sublimate and print passes onto fabric surface
• As this requires no heat setting and little water, it's eco-friendly and the paper is recycled

Direct Digital Printing (DDP)

• Uses inkjet technology and CAD systems that produce best results in all aspects/ applications to textiles
• Reactive dyes print natural fibers (cotton, silk, rayon, viscose), disperse dyes print polyester
• This remains industry application due to high end, large scale machines the only way to print directly
• Designs from home can be bubble jet solution-treated or on sheets
• DDP limited by printer size

Discharge Printing

• It's completed after dyeing
• Print paste destroys dye molecules from print area, used on dark fabrics for white designs
• Discharge usually contains bleaching chemical, remove all discharge residue by ensuring the printing paste doesn't weaken fabric

Dyeing

• Dye is soluble colour in a solution called dye liquor
• It penetrates and combines with fiber, yarn, fabric
• Process comparatively permanently colors fibre, yarn, fabric by immersing in dye bath

Types of Dyes

• Direct: Cellulosic
• Reactive: Cellulosic, wool, silk, acrylic, nylon
• Sulfur: Cellulosic
• Azoic: Cotton, some polyesters
• Vat: Cellulosic
• Acid: Wool, silk, nylon, modified rayon, acrylic, polyester
• Basic: Acrylic, polyester, nylon, discharge prints on cotton
• Disperse: Polyester, nylon, synthetic fibres
• Natural: Primarily on natural fibres

Principles of Dyeing

• To dye it has to be dissolved in water (dye liquor), by the weight of the fabric
• This includes Fibre, yarn, fabric wetted out to help polymers to move
• Fibre, yarn, fabric immersed in dye solution
• It can also bee applied as emulsion/ foam
• Water is cheapest and the best
• Agitation is also applied to assist uptake
• As the textile coloured, the dye molucules go through Migration towards molecule fibre which leads to exhaustion/loss of colour Dye molecules diffusion moves into regions of textile

Stages of Dyeing

• Pre-Fibre Stage
  • Achieved through solution/dope dyeing
  • Pigmentation occurs before extrusion of the solution
  • Good results for hard-to-dye fibers and good colourfastness
• Fiber Stage
  • Includes stock and top dyeing loose fibers before spinning
  • This allows good dye penetration with two tone patterning to occur
  • It has the highest quality, but cost is high
• Yarn Stage
  • Skein/beam dyeing wrap yarns, submerging through the vats.
• Then the dye is circulated
• Fabric and Piece Dyeing
  • Dyeing produces solid color fabrics at cross, made from fibres, so affinity and resistance of dye creates colour pattering
• Union dyeing uniform the colour in fabric pieces

Methods of Dyeing

• Methods depend on the final fabric weight, content, fiber type and type of dye
• Dyeing can be carried out in batches, continuously or in short lengths
• Industry must minimize environmental impact and adhere to restrictions always
• Exhaust/ Batch Dyeing can be used at end fabric, fiber stages which needs a circulation and water
• Its Flexible with colour, low cost and short

Winch Dyeing

• A method with fabric sewn ends and lifted in and out, immersed due to penetration.

Jig Dyeing

• Carries fabric around above the dye bath back and forth, ensuring dyeing is taken place through two rollers at all times
• Can be used with larger quantity of fabric

Pad Dyeing

• Runs through bath in an open rollers width creating pressure, also heat to fix dye
• Economical for fabric lengths

Combination Dyeing

• Includes jet, continuous, and dyeing
• Jet has high water levels jet through the fabric to achieve penetration
• paddle includes systems to rotate equipment to penetration all areas

Artistic Dyeing

• Creates color and resist patterns while prevent dyeing others
• Its a known and practice technique that also inhibits the some dyeing
• Is performed Japan, India, Africa

Appliqué

• Technique where fabric to a backing, which needs to be washable when used
• Use fusible web for some and except knit fabrics
• satin, straight, blanket can be used for methods of finished
• There is reverse which doesnt use it

Embroidery

• Decorating a fabric with materials
• Variety yarns can be used
• Running Stitch
• The length is the same stitch as the fabric

Straight Stitch

• Stitches are not to loose and care must be taken to make sure has care and even length
• Back Stitch
• Used as outline stitch

Stem Stitch

• Also another inline stitches, but the material used, as long

Chain Stitch

• Looped to inlike and outlike, has lazies version where stitches have touch

Cross Stitches

• Stitches are usually work in areas, and half the rows has some corners
• Fly Has Y shaped Loops

French Knot

• Used to fill an area, where threads are turned
• Blanket and Buttonhole stitch

Couching

• Done by using some threads, stitch in place and there is machine where there are utility options

Free Motion Machine

• You can do stuff by allowing a dropping foot so the machine determines legnth and the machine is what's working on it
• Set the foot and machine to the best option
• Work slowly if machine speed is slow
• Then have top samples