Combing Cycle | Basic Principle of a Comber

The combing process is normally used to produce smoother, finer, stronger and more uniform yarns. The carded materials (sliver) contain certain amount of short fibres, neps, fine kitty and leaf particles. Short fibres are a hindrance to spinning of finer counts where the number of fibre in the cross section of the yarn is less. The short fibres cause thick and uneven places in the yarn length and the yarn looks hairy. Apart from this, very short fibres do not contribute any thing to yarn strength. Short fibres below a certain pre-determined length can be easily separated out by using comber. Therefore, combing is commonly confined to high grade, long staple natural fibers. In recent years, combing has also been utilized for upgrading the quality of medium staple fibers.

Combing Sequence/Cycle:
a) Lap feeding by feed roller: The feed rollers S move the sheet w (4-6.5mm) forward, while the nipper Zo and Zu are held open.

Figure: Lap feeding by lap Roller
b) Lap nipping by the nipper: The upper nipper plate Zo lowered onto the cushion plate Zu, so that the fibres are clamp between them.

Figure: Lap nipping by the nipper
c) Combing by the cylinder: The fibre fringe B (fibre protruding from the lap beyond nipping point) is combed by the cylinder comber. Cylinder comber rotates and carries away the short fibres, neps and other impurities.
Figure: Combing by the cylinder
d) Nipper opening and forwarding: The nippers open again and move towards the detaching rollers A.
Figure: Nipper opening and forwarding
e) Detaching roller backward movement: Meanwhile, the detaching rollers A have returned part of the previously drawn off stock (web V) by means of a reverse rotation (web return).
Figure: Detaching roller backward movement
f) Piecing: In the course of forward movement of the nippers, the projecting fibre fringe B is placed upon the returned web V.
Fig: Piecing
g) Combing by the top comb: Before the start of detaching roller operation, the top comb F has thrust its single row of needles into the fibre fringe. As the fibres are pulled through the needles of the top comb during detaching, the trailing part of the fringe is combed.
Figure: Combing by the top comb
h) Detaching roller forward movement: The detaching rollers begin to rotates in the forward direction again and draw the clamped fibres out of the sheet W held fast by the feed rollers S.
Figure: Detaching Roller forward movement
i) Starting a new cycle: As the nipper assembly is restarted, the nippers open for the next feeding step. The top comb is withdrawn. A new combing cycle begins.

j) Cleaning of cylinder comb: The combing cylinder rotates continually and the combing segment is therefore brought into the vicinity of a rapidly revolving brush mounted below the cylinder comb. This stripes the combing segment of fibre impurities, neps etc. and eject them into a aspirator that carries the noil away to a collecting filter drum.
Figure: Cleaning of cylinder comb

Published by
S.M. Hossen Uzzal
B.Sc. in Textile Technology
Monno Fabrics Ltd. Manikgonj


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