Modern Dyeing Machinery and Equipment in Dyeing Process

Modern dyeing machines are made from stainless steels. Steels containing up to 4% molybdenum are favored to withstand the acid conditions that are common. 

A dyeing machine consists essentially of a vessel to contain the dye liquor, provided with equipment for heating, cooling and circulating the liquor into and around the goods to be dyed or moving the goods through the dye liquor. The kind of machine employed depends on the nature of the goods to be dyed. Labor and energy costs are high in relation to total dyeing costs: the dyers aim is to shorten dyeing times to save steam and electrical power and to avoid spoilage of goods. 

The conical-pan loose-stock machine is a widely used machine. Fibers are held in an inner truncated conical vessel while the hot dye liquor is mechanically pumped through. The fiber mass tends to become compressed in the upper narrow half of the cone, assisting efficient circulation. Leveling problems are less important as uniformity may be achieved by blending the dyed fibers prior to spinning. 

The Hussong machine is the traditional apparatus. It has a long, square-ended tank as a dye bath into which a framework of poles carrying hanks can be lowered. The dye liquor is circulated by an impeller and moves through a perforated false bottom that also houses the open steam pipe for heating. In modern machines, circulation is improved at the points of contact between hank and pole. This leads to better leveling and elimination of irregularities caused by uneven cooling. In package-dyeing machines dye color may be pumped in rather two directions: 

• Through the perforated central spindle and outward through the package or 
• By the reverse path into the outer layers of the package and out of the spindle. In either case levelness is important. 

Some package-dyeing machines are capable of working under pressure at temperatures up to 130C. 

The winch is the oldest piece of dyeing machine and takes its name from the slated roller that moves an endless rope of cloth or endless belt of cloth at full width through the dye liquor. Pressurized-winch machines have been developed in the U.S. 

In an entirely new concept, the Gaston County jet machine circulates fabric in rope form through a pipe by means of a high-pressure jet of dye color. The jet machine is increasingly important in high-temperature dyeing of synthetic fibers, especially polyester fabrics. Another machine is the jig. It has a V-shaped trough holding the dye color and guide rollers to carry the cloth at full width between two external, powered rollers, the cloth is wound onto each roller alternately, that is, the cloth is first moved forward, then backward through the dye color until dyeing is complete. Modern machines, automatically controlled and programmed, can be built to work under pressure.

Carding Machine | Objects of Carding Machine | Machine Parts of Carding Machine | Action in Carding Machine | Working principle of Carding Machine

Carding Machine

A process in the manufacture of spun yarns whereby the staple is opened, cleaned, aligned, and formed into a continuous, untwisted strand called a sliver.

Objects of Carding Machine

i. Opening to individual fibers.
ii. Elimination of impurities.
iii. Elimination of dust.
iv. Disentangling of naps.
v. Elimination of short fibers.
vi. Fiber blending.
vii. Fiber orientation.
viii. Sliver formation.

Machine Parts of Carding Machine :

i. Ducting pipe.
ii. Chute feed.
iii. Feed roller.
iv. Transport roller.
v. Brush roller.
vi. Flat.
vii. Fixed carding bars.
viii. Taker in.
ix. Grid bar.
x. Suction duct.
xi. Main cylinder.
xii. Doffer.
xiii. Stripping device.
xiv. Calendaring roller
xv. Coiler.
xvi. Can.

Action in Carding Machine :
The following actions take place in a carding machine.

i. Combing action.
ii. Carding action.
iii. Stripping action.
iv. Doffing action.

i. Combing action :
Combing action takes place feed roller & taken in. Here the pin directions of two surfaces are the same. Combing is the straightening & paralleling of fibers & the removal of short fibers & impurities by using a comb or combs which is assisted by roller & brushed.

ii. Carding action :
Carding action takes place between flat & cylinder.
In carding action,
i. Directions of wire in two surfaces are opposite.
ii. The moving directions of roller are also opposite.
iii. One roller is slower & other is faster.

So carding action is known as “Point against point” action.

iii. Stripping action :
Stripping action takes place between,
a) Taker in and Cylinder &
b) Doffer and stripper.
In stripping action,
i. Wire direction will be the same.
ii. Roller moving direction will be the same.
iii. One roller will be faster than another.
So stripping action is known as “Point back point” action.

iv. Doffing action :
This action takes place between cylinder & doffer. In this place fiber is transferred from cylinder to differ. Low speed doffer is called fiber form of high speed cylinder & makes a condensed web for formation of sliver.

Working principle of Carding Machine :

i. Supplying raw material by ducting pipe.
ii. Chute feed evenly compress a bat of 500-900 kfex.
iii. Transport roller forwards the material to feed plate.
iv. Feed arrangement consists of feed roller & feed plate.
v. Taker in opens the material to small flocks. When the material passes to main cylinder, mote knives, grid bars & carding segments eliminate a great part of impurities.
vi. Grid equipment.
vii. Suction dust to carry away the waste.
viii. Main cylinder & fixed carding segments designed to assist the carding operation.
ix. The main carding operation occurs between flats & cylinder. Flats compromise 80 to 116individual carding bars combined into a band moving on an endless path. 30 to 46 flats are always in action.
x. Cleaning unit cleans stripes fiber, naps & foreign matters from flats.
xi. Grid or cover plate.
xii. The doffer combines the fiber into a web. Because of it’s substantially lower speed relative to the cylinder.
xiii. Stripping device & doffing master draw the web from the doffers.
xiv. Calendar roller calendars the cotton & moves that toward.
xv. At last by can & coiler the fabric is produced.

Conclusion :
Carding is the process of arranging the fiber in parallel fusion. This is necessary for all staple fiber. Otherwise it would be impossible to produce fine yarn. Before the raw stock can be made into yarn, the remaining impurities must be removed. The fiber must be in different angle & they must be straight turned. The card is the hard of the spinning mill & well carded is half spun. Demonstrated the immersed significance of carding for the final of opening operation.