About Carded Nonwoven

Nonwoven card

• Carded nonwoven is manufactured by dry web laying process. And card is the key machine for manufacturing the web.
• Card is a rotating drum or series of drums covered in fine metallic wires or teeth. This is a mechanical process starting with the opening of fibre bale, which are then blended & transported to the next stage by air transport. After that, the fibres are untangled into a web by a carding machine.
• The exact design of cards depends on the fabric weight and fibre properties desirable.
• The orientation of fibres in web can be in four directions\
• Parallel laid
• Cross laid
• Crisscross
• Random laid

Parallel-laid webs

• In the parallel-laid webs, the fibres are laid in a lengthwise orientation. This implies that this type of web has greater strength in the lengthwise direction than the transverse direction.
• According to the demand of mass and fibre type, the parallel-laid web permits the repetition of fibrous webs. The number of layers in the web decides the number of cards required.

Cross-laid webs

• Cross-laid webs are generally made by cross lapper which takes the web from the card at a specific rate. The cross-laid web is laid in several layers with an oscillator carriage on a take-off belt by means of a conveyor belt arrangement. Here the take-off belt moves at right angles to the carriage discretion.
• The cross-laid web has major two purposes:
• To achieve a desired fabric weight,
•  Achieve random orientation of fibre, in the web, for incorporating better strength.

 Random-laid:

• Random Fibre orientation in the web is achieved by incorporating randomizing rolls in the card. Random rolls are generally located between the main cylinder & doffer. The configuration, diameter, & position of the randomizing rolls are different for the different manufacturer.

Tasks of the web-laying machine

• The main job of web-laying machine is:
• Increasing the web mass
• Increasing the web width
• Determining the web strength in the length and cross directions
• Improving the end product quality

Productivity of card

• The productivity of card depends on
• The weight per area of the fabric to be produced.
• Working width of the Card
• Delivery speed
• Efficiency
• The position of the card is assembling with which chemical or mechanical bonding machines (for e.g.  needle punch, hydro entanglement, etc )
  
  
• The production rate of the cars are as follows:
  
  Where:
  P          = Production Rate in Kg/h
  MW     = Web Weight in g/m2
  VL       = Delivery Speed of the doffer  in m/min
  W        = Card Width in m
  E          = Efficiency    

Process flowchart of card with different bonding machine


                                                                                                 
Carded nonwoven fabrics characteristics

• Characteristics of web made from cared dry laid process
• Unique physical properties i.e., elongation in the X, Y & Z direction for moldable applications,
• Ability to attach layers of different type of fiber webs to produce composites,
• High opacity per unit area,
• High strength makes them overwhelming choice for geotextiles fabric,

• Characteristics of fabric made from carded nonwoven dry laid process

The fabric made from this process should have  

• High density
• Good Absorbency capability
• High Strength Modulus
• Soft in feel
• Well Drape-ability
• Lint free
• Contains Excellent cover factor
• Uniformity
• Bulky property
• Ease Printability
• Durable fabrics

Application:

This process is used to manufacture: 

• Needle punch geotextiles, which are used in functions like
• separation,
• filtration,
• reinforcement,
• drainage
• Needle punch carpets, which are used in passenger cars as flooring material.
• Spunlace fabrics have a wide use in various applications such as 
• Baby Wipes,
• Household Wipes,
• Industrial Wipes,
• Consumer remoistened wipes
• Cosmetic Cotton pads,
• surgical gowns,
• drapes,
• operation cover sheets
• Other Miscellaneous Applications
• Headliners,
• Filtration,
• Insulation Felts, etc.