Study of card clothing may be broadly classified into the
following heads:
1. Comparison between flexible and metallic wire clothing.
2. Metallic wire specifications
3. Metallic wire clothing procedure.
comparison between flexible and Metallic wire clothing
Limitations of conventional revolving flat card clothed flexible wires are
The conventional carding efficiency is very, much effected due to frequent stoppages for stripping and grinding. Further, the regularity of the sliver is much affected after every stripping.
Condition of the wire point increases the waste% and neps formation.
Foundation of the flexible wire clothing is not regid and fails to bare the stress and strain caused by high speed, so cannot be run at high speed.
So, In semi high production card, the efficiency of the card is improved by replacement of flexible wire with rigid wire clothing known as metallic wire clothing.
Metallic wire clothing on cylinder and doffer gives the following advantages over the flexible fillets :
1. Reduction in stripping cycles-once in 2 or 3 days
2. No frequent grinding-only light grinding at an interval of 6 months on 3 shift basis.
3. The above two advantages go in favour of more production &
regularity of sliver is improved & labour work is reduced.
4, NO neps formation due to better wire condition,
5, Saving of good fibres.
Lesser variation in card sliver owing to reduced stripping cycles.
Card can run at high speed owing to rigid foundation of wires.
Economic in long run.
some of the demerits of metallic clothing are:
less fibre holding power
It shows slightly higher fibre damage.
High fly generation.
Requires higher power consumption.
Greater care in maintenance and attention owing closer gauging and setting.
It is difficult to replace the damaged wire portion only. (Damaged portion only can be replaced in flexible fillet clothing).
Metallic wire clothing procedure.
How is a card clothed with metallic wires How the ordinary Flat card is prepared before covering with metallic wires.
Following procedure is adopted before the Metallic wire clothing
Check the level of the frame and alignment of cyliner and doffer. Dynamically balance the lickerin, cylinder and doffer.
Metallic clothing demands closer setting than flexible clothing. So, accurate mountaining is essential for successful mountaing.
The cylinder surface is ground before mounting the metallic wire to get even surface.
Ensure that there is a gap of 1" between bare cylinder and doffer
Metallic wire has less than half the height of flexible card clothing. Therfore when a conventional card of lesser diameter cylinder is converted for metallic clothing, the diameter of cylinder and doffer have to be built up, by mounting a base wire of about 4.5 mm in height an 1.5 mm in width. So, the procedure for clothing old lesser diameter cylinder differs slightly from new larger diameter cylinder.
In the case of cards having lesser diameter of cylinder, the following procedure is adopted.
Fig A: Grooving of cylinder to fix L wire on both the edge of cylinder & doffer.
Pig B: Cut the groove with care and fix L wire to the exact dimension,
Fig C: Grooving of L wire to fix the bead wire.
Fig D: Mounting of base wire across the width by using wire mounting equipment is ground.
Base wire is ground by using traverse grinder with grindstone -Wa 36/46 J.V.L.P or A 46/L7v Fig E: mounting of bead wire into the groove already cut on the L-wire.
Fig F Mounting of Metallic wire across the width by using
wire mounting equipment.
L wire is fixed to maintain the position of base wire and bead wire is mounted to maintain the position of metallic wire at the edge of cylinder and doffer and prevent the coming out of wire from the edge of cylinder and doffer.
In the case of card having larger diameter of cylinder. The following procedure is adopted:
Fig G: Grooving of cylinder to fix z wire on both the edge I Fig h: Mounting of z wire
Fig I: Mounting of metallic wire across the width by using wire mounting equipment.
z wire is used on larger diameter cylinder where no base wire is needed.
Metallic wire mounting procedure:
Make a saw cut in the bead or z wire. Bend the metallic wire and insert into the saw cut made in the bead or Z wire. Hammer round the bent portion to form a fine'U' .
With the wire thus attached, bring the pressure arm to the extreme right hand edge.
Place the supply spool of new metallic wire in its creel and thread the wire through tension plate, forming Roller & pressure Roller to the mounting apparatus as shown in Fig.
When commencing to wind, the first few Revolutions should be I wound slowly by hand.
The speed may then be increased upto 16 R.P.M. continue to wind on to the cylinder until the wire nearer the left hand edge, at last solder the wire to ensure the sound joint on each side of cylinder or doffer. After clothing:
Any grease or waxy substances from the wire surface should be removed by washing the wire with petrol or carbon tetra chloride.
The wire Should now be ground for 20 min then burnished for 10 min atlast again ground for 10 min for square off and clean up the point to give a clean carding point under the microscope.
