Explain in detail how you will convert conventional card into High production card or what are the advantages of HP card: what are the special features of HP card & how these features improve productivity and quality Discuss the development that have taken place in carding.
SPECIAL FEATURES OF HIGH PRODUCTION CARD
Following alterations and additions have been made to conventional card, to convert the conventional card into HP card.
Rigid wire clothing known as Metallic wire clothing on cylinder and doffer gives the following advantages.
No frequent grinding & stripping
Saving of good fibres
No neps formation due to better wire condition
less variation in card sliver owing to reduced stripping cycle
Card can run at high speed due to rigid foundation of clothing.
Dynamically Balanced cylinder and doffer helps to achieve close setting and run the card at high speed.
Steel shaft with ball bearing to cylinder & Roller bearing to doffer(instead of cast iron shaft with plain bearing) for extra load of about 150 kg due to metallic clothing.
Rigid, well braced cast iron frames are provided with levelling screw to over come the problem like vibration, fly generation, due to High speed of HP card.
Changing of Existing licker-in under casing to a shirley type or by providing fibre retriever or by providing the comb bar with waste control knife attachment, below the licker in, the following advantages are claimed:
Opening of tuft at high rate of feed is improved
Tufts are distributed as evenly as possible on the cylinder.
Maximum trash extraction with minimum loss of spinnable fibres.
* Viking 200 Precarding segment (64 mm width & 60 points/sq inch) mounted on licker-in side of the cylinder open and card the fibres effectively and allow the flats to be set closer.
* Viking 400 Post carding segment (4 teeth segment with 128 mm width and 150 points/sq inch) mounted on the doffer side of cylinder produce remarkable improvement in yarn quality.
* Evener Roller placed in between cylinder and licker-in at the top, open the large unopened tufts and remove excess fibre on cylinder, and return to the feed Roller again.
* Comb bar- clothed with coarse pitch wire (instead of moteknife) positioned under the feed plate nose, improve the opening and give a pre carding action and gives high trash yield by permitting the trash to separate from the main stream of fibres in the large free space following the comb bar.
* Card cylinder is either made of thick sheet metal sufficiently reinforced and annealed or by special cast iron stabilised, rectified and reinforced by ribbed structure to withstand the stress & strain at high speed of cylinder like 600 PPM.
Many machinery makers has developed stationary flats in place of revolving flats in order to reduce the flat waste and provide maximum carding area and improve the carding quality.
Roller Doffing device in Hp card gives the following advantages
i) Smooth auto doffing at any speed of doffer with absolute web control, 3 to 5 times more production than con-card,
ii) Improved yarn quality by reduction of impurities and neps.
* By providing the latest flat top clothing like/Supra Top or
Rappo Top diamant top, & regid strato top metallic flat clothing,
the following advantages are claimed.
i) Intensive caring. ii) fibre protection, lii) Removal of more short fibres without increasing the amount of waste. iv) High stability suitable for higher production
v) Minimum flat waste, iv) No loading with fibres.
* Electronically controlled Auto leveller in the HP card continuously check the sliver weight and automatically correct the sliver variation and improve sliver and yarn evenness.
* Stop Motion in the feed Roll protect the feed roll and wire points of licker-in from damage due to metal part or thick place in feed. Also stop motion with signal light in calender Roller, coiler hood and coiler unit, stop the card whenever sliver is missing or too thick or thin sliver or chocking in coiler. Changing the coiler head bigger can (24" * 48 ")
Cross apron web doffing system effectively doff and control the web from crosrol unit.
Doffer slow motion drive facilitates the piecing up operation and eliminate the excess waste, during piecing work.
The shirly pressure point system and improved waste suction in card, reduces the dust load in the card room atmosphere by about 90%
Changing the coiler head to work bigger size can (24 inch dia, 48 inch ht) and accommodate more length of sliver and reduce the piecing and improve the efficiency of next machine
Peed region is adjusted for accommodating bigger size laps.
