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Dyeing and PrintingAssignment 1

Topic: To study the mercerizing processSubmitted to: Submitted By : Prof. Pranav Vora DEEPSH KUMAR TOLAMBIACC MFTech DINESH MAKWANANIFT Gandhinagar SHASHIKANT SOLANKI SANJAY BELWAL NADEEM PATHAN Course Name: M.FtechSemester: 2nd Session: 2012 - 2014Submission Date: 1st February , 2013

mercerisationDefinition : Treatment of cellulosic material with higher concentrated Alkali for short period at lower temperature.OBJECTIVESTo improve lustre of cotton materials.

To improve strength and mechanical properties.

To improve dyeability and moisture absorbency.

To improve dimensional stability of materials.

Improving elasticity.

Action of alkaliCotton have resistance to alkali solution.

Mild alkali like sodium carbonate have no action on cotton.

Strong alkalis with higher concentration induce structural and physical changes in cotton fibre.Penetration of alkaliFor small concentration of alkali , less than 5 % no penetration.

As the concentration of alkali increases , penetration increase than automatically fibre swells.What happen to cotton during mercerizationSwelling of the fibre takes place.

Cellulosic chain gets rearranged an become parallel.

De-convolution.

Convolution bean shape to circular shape.

When mercerising can be carried out ?At grey stage.

After desizing.

After scouring.

After scouring and bleaching.Physical changesImprovement in strength.

Improvement in luster.

Change in cross-section from bean shape to almost circular.

Change in longitudinal view convoluted to cylindrical.

Chemical changesFormation of cellulose second .

Improvement in moisture regain (more hydroxyl group).

Improvement in due uptake.

Structural changes

conditionsApplication of caustic soda solution around at a room temperature.

A dwell period of 55 sec. of an average.

Tension at both direction.

Finally , washing-off of alkali from the treated fabric or yarn.

What are the parameters Concentration of NaoH .

Time of treatment.

Tension applied.

Temperature.

Impurities of NaoH.

MERCERISATION MACHINETension mercerisation. (treatment under tension / control).

Slack mercerisation . (treatment without tension / control).Yarn mercerisation.Fabric mercerisation.

Fabric mersarisation machine:Paid chain typePaid chainless typePaidless chainless type.

Hot mercerisation drawback with cold mercerisation Penetration of grey cotton become more difficult. (high viscosity)

Swelling in only at surface . (heavy fabric)

Poor mercerisation at the core and lack of uniformity.

RecipeNaoH = 26 30 %

WETTING AGENT = 1 %

TEMP = 60 centigrades

TIME = 20 TO 60 sec.Advantage of hot mercerisation Rapid alkali penetration.

Improved core mercerisation.

More uniform treatment.

Dwell time can be reduced from 50 sec. to 20 30 sec.

Disadvantage of hot mercerisationLess lustre. (lower swelling)

Higher energy consumption.

Costlier.

Liquid ammonia mercerisationtreatment of cotton fibre with liquid ammonia produces similar effect that of mercerisation.

It is widely accepted for sewing threads ,and special fabric like denim, pillow material, linen etc.

Advantage of ammonia mercerisationLess pollution

Higher productivity.

Jute and linen can be mercerised.

Evenness and uniformity is better.disadvantageVery costly equipment.

Ammonia recovery problem ,leakages will do grate harm to the personnel working .

References..1. Ian Holme, International Dyer, 188(5), 7, (2003).2. Verschuren J.,Kiekens P., New Cloth Market, 18(4), 35, (2004).3. Rouette Hans-Karl, Encyclopedia of Textile Finishing, Springer-Verlag, Berlin, vol no 2, 1613,(2002).4. Ramachandran T., Karthik T., and Shetty Guruprasad S., The Indian TextileJournal,114(9), 23,(2004).5. Ume vohrer, New Cloth Market, 15(7), 13, (2001).6. Zaisheng Cai, Hwang Yoon Joon, Park Yoon-Chewl, Zhang Chuyang, Mccord Marian, Qui Yiping,