Carding/About Carding/Task of the Card/Carding Machine/Types Of Carding

Study On Carding/About Carding

What is Carding?
Carding is defined as the reduction of entangled mass of fibers to filmly web by working them between two closely spaced relatively moving surfaces clothed with sharp points. It is a preliminary process in spun yarn technology just after blow room process.

The Task of the Card ?
01. Opening to individualize the fibres.
02. Elimination of remaining impurities and dust.
03. Disentangling of neps.
04. Elimination of short fiber.
05. Fiber orientation.
06. Producing a uniform continuous strand called sliver.

Functional Zone of carding ?
Generally there are four functional zone of carding:
Feeding Zone
Cleaning Zone
Carding Zone
Sliver formation Zone

Card feeding ?
Card feeding is of two types:
Lap Feed (Conventional)
Chute feed (Modern)
                          (a) Single chute feed system
                          (b) Double chute feed system

Advantages of lap feed system?
1.Linear density of the lap is very good and easier to maintain (uniformity).
2. The whole installation is very flexible.
3. The deviation of card output will be nill as laps can be rejected.
4. Autolevellers are not required, hence investment cost and maintenance cost is less.

Disadvantages of lap feed system ?
1. Transportation of lap needs more manual efforts (more labour).
2. Lap run out is an additional source of fault , as it should be replaced by a new lap.
3. More good fiber loss during lap change.
4. More load on the taker-in  as laps are heavily compressed.

Advantages of Chute feed system ?
High performance of carding due to high degree of openness of feed web.
Labour requirement is less due to no lap transportation and lap change in cards.

Disadvantages of chute feed system?
1. Flock feeding is the only solution for high production cards.
2. Linear density of the web to the card is not as good as lap.
3. Installation is not flexible.
4. Autoleveller is a must , hence invesment cost an maintenance cost is more.

Basic elements of chute feed system ?
01. Conveyer system.
02. Proper control of air pressure.
03. A mechanism to feed the material  at uniform weight per unit length.
04. A delivery system to feed material to card feed rollers.
05. A sensing mechanism to keep a certain amount of material as reserve.

Carding machine ?
Trutzschler carding machine:
Model: TC03, DK903, DK803, DK 760
Rieter carding machine:
Model: C60, C51, C50

Different types of cards ?
01. Revolving flat card:
Card designed for processing of relatively short fibres have flats circulating  on an endless path. So they are referred  as revolving flat cards.
02. Tandem card:
Tandem card consists of two individual cards joined together to make up a unit, in which the doffer of the first cards feeds fiber material to the taker-in of the second card. eg: Crosrol tandem card.
03. Super card:
01. Two or three taker-in instead of one.
02. Cylinder speed up to 800 rpm.
03. Increase of the operating width 1.5 m
04. Production 150 kg/ hour