DENIM PRODUCTION TECHNOLOGIES டெனிம் தொழில்நுட்ப உற்பத்தி முறைகள்

27-02-2011     NRV     This is a preview. The total pages displayed will be limited.  Guest Book at the end.  

2.1 DENIM PROCESS SIMPLIFIED: FROM FIBRE TO FABRIC

Denim process begins with the spinning of raw cotton to cotton yarn. Hundred percent cotton still remains the preferred fabric despite attempts made by denim manufacturers in India and abroad to introduce union denims which has not found any wide acceptance either in the international or Indian market.  Spinning is followed by dyeing of warp yarn to required shades and other weaving preparatory treatments like sizing etc. The yarn is woven into fabric and the fabric is subjected to various finishing processes. The finished material is then checked, packaged and delivered to customers. The production of fabric mainly involves spinning, dyeing and sizing, weaving and processing.

TABLE 2.1 : DENIM PRODUCTION TECHNOLOGIES
Process	Description	Production Technologies
Spinning	Converting raw cotton to yarn	OE/Ring spinning technology
Dyeing & Sizing	Dyeing Cotton Yarn to required shade	Slasher/Rope dyeing systems
Weaving	Converting sized yarn to fabric	Airjet/Rapier
Finishing	Imparting Stability to fabric	Foam/Wet finishing systems

2.2 CHOICE OF TECHNOLOGY & THE PROCESS SEQUENCE

2.2.1 Open End Spinning – v – Ring Spinning

Denim plants have both open-end and ring denim capabilities, although a majority of the capacities are open-end, which historically cater to mass-market denim products. However, open-end plants are also able to manufacture specialty denim fabric with changes to their processes. Ring spun denim is of a higher quality and commands higher prices in the denim fabric market. The process sequence of OE and ring spinning are given in the following Table 
2.2

TABLE 2.2 : SPINNING -PROCESS SEQUENCE
SPINNING	OE  SPINNING TECHNOLOGY	RING SPINNING TECHNOLOGY
	Blow room	Blow room
	Cards	Cards
	Draw frames	Draw frames
	OE Spinning	Speed frames
		Ring frames
		Winders

2.2.2 Rope Dyeing – v – Slasher Dyeing

The rope method is generally used in the mass production of fabrics with set specifications. The slasher method is generally used in smaller scale production of fabrics and allows for modification of specifications. Rope-dyeing technology provides a uniform dye to denim fabric when compared to the slasher-dyeing process. Steps involved in the Slasher Process and Rope process are as follows:

TABLE 2.3 : DYEING - PROCESS SEQUENCE
DYEING & SIZING	SLASHER DYED PROCESS	ROPE DYED PROCESS
	Beam Warping	Ball-Warping
	Sheet Dyeing and Sizing	Rope-Dyeing
		Long chain Beaming
		Sizing

2.2.3 Foam Finishing – v – Wet Finishing

While application and distribution of chemicals is quite uniform in wet finishing, the practical alternative to reduce energy bill is to use foam technology. The foam finishing is environmentally-friendlier and reduces pollution. The Table below depicts the process sequence adopted.

TABLE2.4:FINISHING-PROCESS     SEQUENCE
FINISHING	FOAM TECHNOLOGY	WET TECHNOLOGY
	Brushing	Brushing
	Singeing	Singeing
	Finishing(foam)	Finishing(wet)
	Antitwisting	Antitwisting
	Shrinking	Shrinking