Seminar On Development in Card WireSubmitted to: Submitted by:Mr. Suman Bhattacharya Mukul ChandelTextile Department M.tech (T.T)
DEVELOPMENT IN CARD WIRE CLOTHINGINTRODUCTIONThere are two rules of cardingThe fibre must enter the carding machine, be efficiently carded and taken from it in as littletime as possibleThe fibre must be under control from entry to exitControl of fibres in a carding machine is the responsibilitgy of the card clothingFollowing are the five types of clothings used in a Carding machine Cylinder wire Doffer wire Flat tops Licker-in wire Stationary flats CYLINDER WIRE: Cylinder clothings play a major role in cotton processing when it comes to optimal reduction of neps and dirt particles. The quality of a cylinder wire itself, in turn, is primarily determined by a high precision during manufacturing and the selection of optimum tooth geometries. Cylinder wires TCC-Star guarantee a reproducible and consistently high quality.TCC uses high-quality, micro-alloyed steel grades, which guarantee a long service life and high eco-nomic efficiency. FG/FGX1* The first maintenance-free cylinder clothing The most remarkable characteristic of this wire is the straight tooth back. The most important features of the wire are owed to this tooth back.
The tooth back keeps the fibres on the surface and thus ensures an intensive interaction with the flat tops. There is enough space,however between the rows of teeth for the fibres to get out of the way, thus gentle carding is guaranteed.Feedbackfrom the spinning mills confirms IPI values that are about 15 % better. The long tooth back forms a robust carding edge. Wear is considerably lower than with filigree-shaped teeth. In practice, resharpening of FG clothings is eliminated, which means no maintenance. The FGX1 wires are available in four different finenesses, depending on the application: • 662 ppsi • 760 ppsi • 827 ppsi • 949 ppsi Application wire identification code ppsi angle base width Cotton T17.40.040.0949.05/FGX1 949 40° 0.40 mm man-made fibers recycled cotton T17.40.050.0662.05/FGX1 662 40° 0.50 mm blends viscose miscellaneous T17.40.050.0760.05/FGX1 760 40° 0.50 mm TOOTH DEPTH :-Shallowness of tooth depth reduces fibre loading and holds the fibre on the cylinder in the ideal position Under the carding action of the tops. The space a fibre needs within the cylinder wire depends upon its Micronaire/denier value and staple length should have to be reduced. The recent cylinder wires have a profile called "NO SPACE FOR LOADING PROFILE"(NSL). With this new profile, the tooth depth is shallower than the standard one and the overall wire height is reduced to 2mm, which eliminates the free blade in the wire. This free blade is responsible for fibre loading.
Once the fibre lodges between the free blade of two adjacent teeth it is difficult to remove it. In order to eliminate the free blade, the wire is made with a larger rib width FRONT ANGLE: - Front angle not only affects the carding action but controls the lift of the fibre under the action of centrifugal force. The higher the cylinder speed, the lower the angle for a given fibre. Different fibres have different co-efficients of friction values which also determine the front angle of the wire. If the front angle is more, then it is insufficient to overcome the centrifugal lift of the fibre created by cylinder speed. Therefore the fibre control is lost, this will result in increasing flat waste and more neps in the sliver. If the front angle is less, then it will hold the fibres and create excessive recyling within the carding machine with resulting over carding and therefore increased fibre damage and nep generation. Lack of parallelisation, fibre damage, nep generation, more flat waste etc. etc., are all consequences of the wrong choice of front angle. TOOTH PITCH : - Each fibre has a linear density determined by its diameter to length ratio. Fine fibres and long fibres necessitates more control during the carding process. This control is obtained by selecting the tooth pitch which gives the correct contact ratio of the number of teeth to fibre length. Exceptionally short fibres too require more control, in this case, it is not because of the stiffness but because it is more difficult to parallelise the fibres with an open tooth pitch giving a low contact ratio. RIB THICKNESS :- The rib thickness of the cylinder wire controls the carding "front" and thus the carding power.
Generally the finer the fibre, the finer the rib width. The number of points across the carding machine is determined by the carding machines design, production rate and the fibre dimensions. General trend is towards finer rib thicknesses, especially for high and very low production machines. Rib thickness should be selected properly, if there are too many wire points across the machine for a given cylinder speed, production rate and fibre fineness, "BLOCKAGE" takes place with disastrous results from the point of view of carding quality. In such cases, either the cylinder speed has to be increased or most likely the production rate has to be reduced to improve the sliver quality POINT POPULATION :- The population of a wire is the product of the rib thickness and tooth pitch per unit area. The general rule higher populations for higher production rates, but it are not true always. It depends upon other factors like production rate, fineness, frictional properties etc. TOOTH POINT :- The tooth point is important from a fibre penetration point of view. It also affects the maintenance and consistency of performance. Most of the recent cylinder wires have the smallest land or cut-to-point. Sharp points penetrate the fibre more easily and thus reduce friction, which in turn reduces wear on the wire and extends wire life. Doffer wires :- The doffer is a collector and it needs to have a sharp tooth to pick up the condensed mass of fibres circulating on the cylinder. It also requires sufficient space between the teeth to be efficient in fibre transfer from the cylinder, consistent in the transfer rate and capable of holding the fibre under control until the doffers stripping motion takes control. TCC doffer wires excel particularly in safe running properties with a high level of production. Their special surface quality (scale free) prevents the accumulation of foreign particles as well as fibre damage Side grooves on the teeth ensure safe web guiding. The risk of damage thus is lower.
TCC doffer wiresApplication wire identification code base width Angel ppsiMMF, blends T40.30.090.0367.31/BRZ 0.9 mm 30° 367100 % MMF Novodoff 30 - - -100 % cotton T40.30.090.0367.31/BZ 0.9 mm 30° 367100 % cotton T40.30.100.0280.28/BZ 1.0 mm 30° 280Others T50.30.100.0304.37/Z 1.0 mm 30° 304bleached cotton T40.34.090.0282.28 0.9 mm 34° 282bleached cotton T40.34.090.0282.28/X 0.9 mm 34° 282bleached cotton T40.30.100.0280.28/BZ 1.0 mm 30° 280 Until recently 0.9mm rib thickness is standardised for doffer wire, regardless of production and fibre characteristics .This rib thickness has been found to give optimum results. However doffer wires with a 0.8mm rib thickness have been introduced for applications involving finer fibres. In general 300 to 400 PPSI (points per square inch) has been found to perform extremely well under most conditions. Doffer wire point population is limited by the wire angle and tooth geometry. Higher population for doffer does not help in improving the fibre transfer. As the production rate rises,
the doffer speed also increases. The doffer is also influenced by the centrifugal force, as is the cylinder. But cylinder wire front angle can become closer to counter the effect of centrifugal force to close the front angle on a doffer wire would reduce its collecting capacity and result in a lowering of the production rate. The solution is to use the wire with striations, which will hold the fibre until the doffer is stripped. The hardness of the doffer wire is a degree lower than that of the cylinder but sufficiently hard to withstand the forces generated in doffing and the resultant wear of the wire. The reason for this slightly lower hardness requirement is the longer and slimmer tooth form of the differ wire. The fibres which are not able to enter the wire will lay on top, i.e. completely out of control. Therefore instead of being carded by the tops the fibres will be rolled. Similarly a fibre buried too deep within the cylinder wire will load the cylinder with fibre, weaken the carding action and limit the quantity of new fibres the cylinder can accept. Therefore, the production rate would have to be reduced.Lickerin wires :- Licker-in with its comparatively small surface area and small number of cardingteeth, suffers the hardest wear of all in opening the tangled mass of material fed to it.The use of special steel grades imparts long service life to our lickerin wires. Depending on theapplication, TCC, here too, uses the particularly high-quality NovoStar steel grade. Based uponthis, optimised tooth geometries adapted to the raw material, to the lickerin arrangement, andto the lickerin diameter ensure a gentle pre-opening of the fibre material.TCC lickerin wires areavailable as interlinked wires and as wires for mounting in grooves.
TCC lickerin wires for 3-lickerin cardsRaw material applicatio designation wire identification code base width angle ppsi100 % cotton Trützschler cards 1st roller, pinned100 % cotton Trützschler cards 1st roller T50.10.210.066.35/V 12 rows/’’ 10° 66blends; MMF Trützschler cards 1st roller T50.00.315.0034.34/V 8 rows/’’ 0° 34recycled flex cards Trützschler cards 1st roller T50.00.315.0034.34/V 8 rows/’’ 0° 34cotton combed long staple Trützschler cards 2nd roller T50.20.160.0164.35/V 16 rows/’’ 20° 164all Trützschler cards 3rd roller T50.20.160.0210.35/VB 16 rows/’’ 20° 210all Rieter C 60 1st lickerin T50.10.210.0122.34/V 12 rows/’’ 10° 122cotton Rieter C 60 1st lickerin T50.05.180.0131.34/V 14 rows/’’ 05° 131blends, MMF Rieter C 60 2nd lickerin T50.20.210.0122.42/V 12 rows/’’ 20° 122any Rieter C 60 3rd lickerin T50.20.160.0210.35/V 16 rows/’’ 20° 210 Licker-in with its comparatively small surface area and small number of carding teeth, suffers the hardest wear of all in opening the tangled mass of material fed to it. It is better to use Licker-in roller without groove. Interlocking wires are used for such type of licker-ins. This avoids producing the eight precise grooves and to maintain them throughout its life.Flat tops TCC-TOPFlats fabric and hooks - simply a clever designFlat tops mainly consist of the flats fabric and of the hooks. Both of them have an enormousinfluence on carding quality. TCC uses a “multilayer foundation” in the web construction,with
the covering layer always consisting of a permanently elastic natural rubber. A flats fabricconsists of up to seven single layers that are constructed like a sandwich.The wires used aremade of micro-alloyed steel and are always additionally hardened by TCC.Computer-optimised,biconvex wire cross-sections and the special geometry of the tips (only half as wide as a cylinderwire) reduce wire movement during the carding process. Thus the so-called excessive breakingis reliably avoidedThe diagrams show the Structure of a classic flat bar and of a MAGNOTOP flat bar withclothings.1 Aluminium flat bar2 Flat clips3 Clothing strips4 Adhesive and compensation layer5 Neodymium magnet6 Thin metal strip
USE OF STEEL ALLOY IN MANUFACTURING OF CARD WIRE BASED UPON APPLICATION AND DEMAND CARD WIRE IS MANUFACTURED FROM DIFFERENT ALLOY STEEL :- ULTIMA (TUNGSTEN,VANADIUM ALLOY STEEL) CHROMA (CHROMINU ALLOY STEEL) PERFORMA (HIGH TENSILE SPECIAL ALLOY)
Integrated Grinding System (IGS)The inevitable wear of the card clothing be-comes an even more crucial issue withany high production card. The Integrated Grinding System (IGS) - a unique Rieterfeature -solves this fact fundamentally by keeping the wires sharp at all times.The advantages are:• Constant sliver quality over the lifetime of the wires• Better carding i.e. trash and neps reduction due to constant sharp wires• No downtime for the grinding of cylinder and flat clothing since it is a fullyautomated and computer controlled system• Strongly reduced maintenance load• Prolonged lifetime for cylinder wires and therefore very economical• Ideally suited for the latest wire technologies which are difficult to grindmanually
The IGS system for the wire maintenance ensures a consistent high sliver quality, increases thelifetime of the wire set and reduces the maintenance downtime to an unmatched level.