An Overview of Carding Cylinder

An Overview of Carding Cylinder

Bhavdip Paldiya
Dept. of Textile Technology
Sarvajanik College of Engineering & Technology, Surat, India
Cell: +91 9662020909
Email: bhavdipk9009@gmail.com

What is Cylinder:
The carding cylinder is usually manufactured from cast iron, but is now sometimes made of steel. Most cylinders have a diameter of 1280-1300 mm and rotate at speeds between 250 and 500 rpm.

Specification of Cylinder:

1. DIAMETER  : 50”(120 mm)
2. SPEED  : 250-500 rpm
3. WIRE POINT PER INCH: 550-650 
4. SURFACE SPEED: 1000ft/min.
5. TOTAL WIRE POINT: 30lac
6. WIRE POINT DIRECTION: Anti clock

Objectives of Cylinder:

1. Back plate:

• To hold the fibre.
• To prevent the development of undesirable air current.

2. Top feather edge sheet: It controls the wt. & thickness of the flat strips.

3. Cylinder stripping door: This door is used to strip the wire point of cylinder.

4. Bottom sheet:

• To hold the fibre.
• To prevent the development of undesirable air current.

5. Cylinder undercasing:

• Remove dust.
• To maintain constant airflow.

Types of Cylinder:
There are two types of cylinder.

1. Single cylinder
2. Double cylinder

1. Single cylinder carding machine:

Single cylinder carding machine

Specifications

• Cylinder Dia. 700mm
• Output: 100-250kgs/h
• Power: 18.5kw

Application

• This machine can open various baled fiber,and send to next procedure via fan.
• It opens fiber with pin plate,high production and good quality

A brief feature of single cylinder:

• Single Cylinder Carding Machine, up to 1.5 meters in diameter and up to 2.5 meters in width are produced as normal standard. 

• Cover all types of fiber from very fine to very coarse fiber deniers; fiber lengths up to 120 mm can be processed. Both synthetic and natural fibers of all types can be processed.

• Cylinders up to 1.5 meters in diameter and up to 2.5 meters in width are produced as normal standard. Carding machines outside this size range can be discussed dependent on ard main cylinders are balanced to a surface speed of 1500 meters / per min. 

• All types of carding machines both single and double doffers can be fitted with randomizer rollers or not dependent on customer’s needs. 

• Card wires can be supplied as surface wound or interlocking as required. 

• Card capacity is depending upon card type, fiber denier, types of fiber but can be excess of 800 kgs / per hour. 

• Other details and variables dependent on customer’s needs can be discussed with our technical staff. clients’ individual requirements.

2. Double cylinder carding machine:

Double cylinder carding machine

SPECIFICATION :

• ™ Middle cylinder diameter: Φ850mm,Φ635mm
• ™ Big cylinder diameter:Φ1230mm,Φ1020mm
• ™ Power:35KW

Application:

• Double doffer used for carding and mixing opened chemical fiber and blending material.

New type of double carding m/c

Specifications

• Product Name - double cylinder carding machine
• Working width: 1800mm 2000mm 2200mm 2500mm
• Capacity: 150kg/h 200kg/h 300kg/h
• Dia. of cylinder: 1230mm
• Speed: 20 - 50m/min

Application:

• Various kinds of fiber such as polyester,viscose,nylon,PP,fiberglas,etc

Cylinder Speed:

1. Higher cylinder speed helps fibre transfer. Higher the production, higher should be the cylinder speed.
2. Higher cylinder speed improves carding action, thereby imperfections are reduced

Cylinder Wire Selection:
Cylinder wire selection is very important, it depends upon cylinder speed, the raw material to be processed and the production rate.

The following characteristics of cylinder wire should be considered.

1. Wire angle
2. Tooth depth
3. Wire population
4. Rib thickness
5. Tooth profile
6. Tooth pitch
7. Tooth point
8. Overall wire height

Cylinder Wire Maintenance:

• For a modern cylinder wire of 2mm height, grinding with the normal grinding stone is not recommended. It is better to use TSG grinder to grind the wire every 2nd or 3rd month, so that the sharpness of the wire is always maintained. 

• TSG grinder does not grind the wire, therefore if the wire is worn out very badly the quality improvement using this grinding machine will be nil. Frequent grindings are recommended. If TSG grinder is not available, it is better not to grind 2mm wires. 

• The number of traverse should increase depending upon the life of the wire. The number of traverse for successive grindings should be like this 3, 5, 10, 17 etc. Anyway the best method is to confirm with the microscope. If the grinding is not sufficient, the number of traverse should be increased.

Cylinder Construction in Modern carding
The cylinders of modern carding machines are almost solely welded constructions (Fig. ). They consist of the shell reeled of metal sheet welded along its edges, bottoms with hubs stiffened with ribs, the shaft and the reinforcement rings. Such constructions are used by leading carding machine manufacturers, and particular solutions are different as to the side hubs construction and reinforcement rings

Cylinder Construction

Loads acting on the main cylinder of carding machine
The loads acting on the cylinder result from:

• The influence of fiFIBER on the teeth of card wire during the carding process; the forces are small and are omitted when calculating deflection of the cylinder shell, 

• The construction deadweight and the centrifugal force; their influence on the cylinder deflection may also be neglected due to small rotational speed of the cylinder (circa 100200rpm), 

• Reeling at tension of the metallic card wire.

Tension forces acting on the metallic card wire coils

Reeling at tension S and the reeling pitch t of the card wire on the cylinder with the radius R (Fig. 3) exerts pressure on the cylinder shell directed radially inward with the value of

• Radial pressure = pr
• Force =F
• Surface force =px

Setting between cylinder and doffer
If the setting between cylinder and doffer is very close, the wires will get polished and this will affect the fibre transfer. If the setting is too wide, the fiFIBER will not be transferred to doffer from the cylinder, hence cylinder will get loaded. While processing synthetic fiber cylinder loading will badly affect the yarn quality. Moreover, it is difficult to improve the wire condition if the loading is severe. The only solution would be to change the wire. Therefore enough care should be taken while processing synthetic fiber.

Setting between cylinder and doffer

The setting between cylinder and flat

• The most critical setting in a carding machine is between cylinder and flat tops. While processing cotton, it can be as close as 0.175 mm provided the mechanical accuracy of flat tops is good. 

• Closer the setting between cylinder and flats, better the yarn quality. Neps are directly affected by this setting. Of course, very close setting increase the flat waste. For processing cotton the setting can be 0.25, 0.2, 0.2, 0.2, 0.2mm. For synthetic fiber it can be 0.3, 0.25, 0.25, 0.25, 0.25mm. 

• The setting between cylinder and flats can be as close as possible.

The setting between cylinder and flat

Heal and Toe Arrangement
The top half of the cylinder is surrounded by a series of flats. The flats are also covered with wire teeth, the points of which oppose & are set close to the wire on the cylinder. The setting between flats & cylinder is arranged that there is a wide3r setting at the back or trailing edge on which cotton first reaches for being carded & closer setting at the leading edge where the cotton leaves the flat. This arrangement is generally termed as ‘Heal & Toe’ arrangement.

Heal & Toe’ arrangement

Importance: The object of this type arrangement is to effect a gradual opening & carding of the fibers at each flat.

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