Carding Machine Important Question

Q. Define carding / Heart of spinning?

Ans. Carding may defined as the reduction of an entangled mass of fibres to a filmy web by working between two closely spaced, relatively moving surface clothed with sharp wire points. The carding is the heart of the spinning mill & well carded is half-spun-demonstrate the immense significance of carding for the final result of the spinning operation. The importance of carding is still greater where new spinning systems are concerned.

Q.  Mention the objective of carding (in brief)?

Ans. 

•  Opening to individual fibres: The blow room only opens the raw material  to flocks where as the card opens it to the stage of individual fibres. This enables the elimination of impurities & good performance of the other operation.
• Elimination of impurities & dust: Elimination of foreign material occurs mainly in the region of the taker in (T-in). In addition to free dust, which can be directly sucked away as in the B/R, the card also removes a large proportion of the micro particles. The card is a good dust removing m/c.
• Removing of neps: The card reduces the no. of neps from the B/R. Actually neps are not eliminated at the card, they are mostly opened out. An improvement in disentangling of neps is obtained by: closer spacing between the clothing, sharper clothing; optimal speeds of the T-in; low doffer speeds lower through put.
• Elimination of short fibres: Short fibres can only be eliminated if they are passed into the clothing. Elimination of short fibres in the card must be viewed in proportion, actually very small, fewer than 1% short fibres.
• Fibre blending: The card is the only m/c to process individual fibres. In formation of the web & with repeated rotation of the fibres on the main cylinder, intimate fibre with fibre mixing is achieved.
• Fibre orientation: It is often attribute the effect of parallelizing. The card can be given the task of creating partial longitudinal orientation of the fibres.
• Sliver formation: To deposit the fibre material, to transport it & process it further, an appropriate product must be formed.So, carding is called heart of spinning.

Q. Describe different action occurred in card machine?

Ans. 

1.  Carding action: If two closed surfaces have opposite wire direction & their speed direction or relative motion is also opposite, then the action between two surfaces is known as carding action.

•  It is occurred between flat & cylinder.

•  Here wire direction is opposite.

•  Speed direction is opposite.

•  There always should be point against point direction result of carding action. Result of carding action -

•  Maximum individualization of fibres is achieved in this region by opposite spikes.

•  Neps, short fibres, dirt & dust are removed.

•  The difference of surface speed between cylinder & flat is more. So, carding action is max^m occurred.

2.  
Stripping action: When two close surfaces have same wire direction & their speed direction or relative motion is also same then the action

between two surfaces is called stripping action.

•  It is occurred between T-in & cylinder.

•  Same wire direction.

•  Same speed direction.

•  There always should be against back action. Result of stripping action-

•  Trash, neps are transferred from cylinder to Taker in & doffer to stripper by stripping action.

3.  Doffing action: When two close surfaces wire points are inclined in

opposite direction & their speed direction is same, then the action between two surfaces  is called doffing action.

Doffing action is occurred betⁿ cylinder & doffer. Wire direction is opposite but speed direction is same. It is special type of carding.

Sliver formation – is done by this action.

 4. Combing action:

This action take place betⁿ feed roller & T-in. Here, pin direction is same.