Reactive & pigment printing

This slide about Reactive & pigment printing process.

1. WELCOME TO OUR PRESENTATION

2. MAJHARUL ISLAM BTE00505254

3. TOPIC NAME REACTIVE & PIGMENT PRINTING

4. Introduction Reactive dye printing is a method of printing a dye or wax by using mixes thereof to create colors. With a binder and a heat-activated printing additive images can be permanently bonded to the substrate. These reactions are generally heat-activated.

5. This can be described as: Here, > Chromophore Group (Azo, Anthaquinone, Phthalocyanine , Metal complex group) >Bridging Group ( Amino, Ethyl &, etc) Methyl, Oxide, Sulphide group) >Reactive Group (- Cl , -Br, -SH, -OCH)

6. HISTORY On the occasion of 100 year’s celebration of synthetic dye manufacturing, two chemists of ICI company (UK) named Stephen and Rattee tried to manufacture a new dyestuff. Thus they succeed to invent a new dye in 1956, which was named REACTIVE DYE. This was manufacture for dyeing cellulosic fabrics. The first three reactive dyes were PROCION YELLOWR, PROCION BRILLIANT RED 2B and PROCION BLUE 3G.for this effort they were awarded gold medal of the society of dyes and colorists for the year 1960.   

7. Popularity of reactive Printing: Reactive printing are mostly used for printed cotton fabric. Popularity of reactive printing: Ability to procedure bright shades of wide range. High leveling quality. Good washing fastness. Good light fastness. Low temperature dyeing (below 100 C) Lower cost Na – Alginate thickener is required. For the above reasons reactive printing are more popular. 

8. FABRIC PRINTING By reactive printing the following fabric can be printed : Cotton Rayon Flax & Other Cellulosic fabric

9. PROPERTIES Reactive dye is anionic in nature. Reactive dye is a water soluble dye. They have better wash and light fastness properties. They have better substantiality. They form strong co-valet bond with the cellulosic fiber. Alkaline condition is must required for dyeing. Na – Alginate thickener is required. A certain amount of dyes are hydrolyzed during application. Wide range of color can be produced with reactive dyes. Comparatively cheap in price.

10. Classification of reactive dyes: On the basis of dyeing temperature : Cold brand : These types of dyes contain reactive group of high reactivity. So dyeing can be done in lower temperature i.e. 20 -40 C. they are highly reactive with fibre on this temperature . b) Medium brand : This type of dyes is applied in a medium temperature range is between 50 -70 C .There reactivity is medium with fiber . c) Hot brand: This type of dyes as very low reactivity properties with comparison with medium and high brand reactivity. Dyes isd carried out above 80 C .

11. Flow Chart of Reactive Printing Pre-treatment ( Singeing, Desizing, Scouring Bleaching, Mercerization.) ↓ Printing (with seq.agent , alkali, dyes, glycerin, thickener, binder)  ↓ Curing  (Fixation of the printed dye , (Temp.130-160°C within 30-60s) ↓ Drying  

12. PIGMENT PRINTING Pigments are colors which do not dissolve and penetrate into the fibers. They have not be applied together with a film forming binder. More than 50% of all printing colors are pigment types . It represents an alternative to direct printing. In this system there is no need to carry out a steaming process.

13. HISTORY The economic importance of pigments in printing is substantial since around 1960 these have become the largest colorant group for textile prints. For more than 3000 years, mineral pigments have been ground with natural binding agents and ‘applied’ to the textile to form a pattern. Even though pigment printing is the oldest printing method, it was unimportant until the Second World War because of the poor results of the technique, dull colours, loss of textile character as a result of hardening, and poor fastness to wear and washing. In the 1920s dispersions of useful organic pigments like those found in pigment printing today were available on the market. In the 1930s emulsion copolymerisation of olefinic substances was discovered at the former IG Farben in Leverkusen and Ludwigshafen. In 1937 the first pigment printing pastes based on water-in-oil (w/o) emulsions were developed in the USA by interchemical Corporation.

14. Flow Chart of Pigment Printing Pigment printing is carried out as the following way : Fabric Pre-treatment ↓ Table preparation ↓ Fabric plaited on the table ↓ Pigment printing paste apply with the help of screen ↓ Drying (90-100%/110-120°C) ↓ Curing at 160ºc (belt speed 6.50 m/min) ↓ Washing (Some time is not need) ↓ Delivery 

15. Components Of Pigment Printing A pigment printing system consists of three essential components:   1.Pigment dispersion: Specific pigments are treated in a grinding mill in the presence of suitable non-ionic surfactants. A particle size of 0.1-3 μm is typical. Generally, the pigment pastes are aqueous based and contain the dispersing agent. 2. Binders and cross-linking agents (polymers): The binders used in pigment printing systems are film-forming substances made up of long-chain macro molecules which, when heated with a suitable acid-donating catalyst, form a three-dimensional structure in the pigment. 3.Thickeners and auxiliary agents: These give the required print thickening power

16. CHARACTERISTICS A good quality of pigment printing contain some characteristics. Brilliance and high color value related to pigment concentration . Minimum stiffening in the handle of the textile. Acceptable fastness properties.

17. ADVANTAGES Applicable to natural and synthetic fiber. Wide range of color can be produced. Can be used for dope dyeing for filament yarn. Easily applicable. Less expensive. Maximum output of goods because of the elimination of washing-off. quick sampling and high printing speed. Good color fastness properties . Properly produced pigment prints, using selected products. Extremely well suited for color resist effects, for example, under azoic and reactive dyes.

18. DISADVANTAGES Not controllable for the binder film . The jamming up of equipment and air and water pollution is observed. Wet and rubbing fastness is average. The handle of the printed goods is often unduly hard because of the large amounts of external cross linking agents. The original surface of the textile material is covered by the binder film. This is occasionally aesthetically effective but usually undesirable

19. Application of Pigment Printing: Uses of Pigment printing is wide range. The garments of the women which are made by cotton, polyester or viscose blends are printed by pigments if the medium color depths are needed. Decorative curtain, towels are printed by pigments. Pigment printing also used in bed linen, aprons, children’s garments, night wear dresses, various cottons and cellulose materials.        

20. CONCLUSION Reactive printing & pigment printing both are very useful in textile sector. Now a days reactive printing mainly used for cellulosic fabric like cotton , where reactive dyes and binder used. Pigment printing can be used for all kinds of fabric, where washing & fixation are not required. So both are importance