Chute Feeding or Aero Feed System in Carding

Chute Feeding or Aero Feed System in Carding
Bhavdip Paldiya
Dept. of Textile Technology
Sarvajanik College of Engineering & Technology, Surat, India
Cell: +91 9662020909
Email: bhavdipk9009@gmail.com





Chute Feed System:
Chute feed is a system of feeding small tufts of cotton fibres directly from blow room to a series of cards, arranged in a circuit through pneumatic pipe.

A condenser in the pneumatic pipe sucks the material from blow room and delivers it to the flock feeder through pneumatic pipe by way of the filling trunk.
Chute Feed System
Chute Feed System
Photo electric cell in the filling trunk regulates the supply of material from blow room. From here, the material is fed to the kirschner beater by way of two ridged roller and two feed rollers. Krischner beater open the cotton into desired size tufts.

A fan blows the tufts from the kirschner beater into horizontal c closed circuit loop situated above the cards. The return trunk has the duty of returning the surplus material(after the supply to last card) to the beater that also of uniting well opened material with supply of fresh material thus delivering it directly to the horizontal duct again.

The separating head arranged in the horizontal closed circuit loop divert the part of tufts from air current into vertical feed chutes above the card inlets. Vertical feed chute ensures a uniform supply of material over the full working width of the card. Uniform separation of the tufts from the air current is achieved by adjusting the nose in the separating head. Raising the leading edge produces more separation and vice versa.

The weight of the card feed per meter depends on the static excess pressure in the installation. This drops practically linear from separator to separator by about 2mm head of water. The weight of the feed per unit length must be adjusted in accordance with this drop by increasing or deducting the distance between the glass front and the rear wall of the feed chute. The weight per meter ranges between 600 to 700 gms.

Thus while deviation of the card sliver count from one card to another must be regulated with the glass plate. The specific count of the sliver itself must be adjusted with the count change wheel.

Card Feed Chute: 
The feed weight at the card depends on the static pressure in the aerofeed system and the chute depth adjusted. Since the pressure diminishes from one feed chute to another, the chute depth must be matched accordingly. It can be varied from 80 mm to 120 mm and is read off on the scale at the arrow mark.

THEORY AND LITERATURE
The blow room machinery is linked to the cards by trunking and the opened cleaned cotton is conveyed by pneumatic means to each card – this the principle of chute feed system.

The basic elements of chute feed system are :
  • Conveyor system to carry material from B/R to group of cards with the help of air.
  • Proper control of air pressure in the conveyor system for smooth flow of material.
  • A mechanism to feed the material at uniform weight per unit length and width.
  • A delivery system to feed the material to the card feed roller.
  • A sensing mechanism at chute to keep a certain amount of material as reserve and also to control the feed of material to the chute.
Present Development :
Automation – bale to cone : continuous automated spinning (CAS) in Japan
  • Platts chute feed system type 685
  • Exact feed FBR chute feed system by trutzschler, germany
  • ML snowflaker chute feed by U.S.A
  • NSE chute feed system of bombay
  • Vibra chute DS by W,.Germany
  • Rando level feed by U.S.A
  • Transautomal by Italy
  • Aerodome by Switzerland
Views of Indian Mills :
The only reservation that seem to have is that its introduction in the processing line may result in high yarn count variations. This should not be so since C.F system has gained good acceptance in all the textile mills in advanced countries.

Lap Feed Demerits:
  • Stoppage due to lap changes.
  • Extra labour for lap trasportation
  • Compression of fibres in the lap poses problem during opening in carding.
  • More wastes due to lap tails and damages.
  • Irregularity of sliver weight due to improper unwinding of laps.
Chute Feed Merits:
  • Direct automatic feed to card increases B/R working efficiency.
  • Elimination of Man power during scutcher operation.
  • Processing of rejected lap is avoided.
  • Due to loose form of feeding of fibres trash particles can be removed easily during carding.
  • Suitable for synthetic fibres of bulky in nature, avoiding
Advantages of flock feeding or chute feed system :
  • The automatic continuous feed directly linked to the blow room eliminates the lap formation. This increases the working efficiency of the blow room. 
  • The main power requirement in doffing the lap, weighing, transportation to card and feeding at the card is eliminated. 
  • The processing of rejected laps in the blow room is avoided. 
  • The fibres are fed to the card in loose sheet form as against compressed form so that trash particles can be easily extracted from fibres by the carding action. 
  • Excessive sliver irregularities due to the lap licking during high humidity, double lap feeding, lap splitting, lap piecing etc, are eliminated. 
  • When compared to lap fed, there is a reduction of 1 % CV flock feeding card sliver. 
  • Crushing of foreign materials seed bits and other trash particles during calendering and difficulty of removing a subsequent processes is reduced.
Disadvantages or limitations of chute feed system :
  • Blow room should run the same number of hours per week as the cards do. 
  • The card production must be kept excessive to assure continuous feed to drawframe at the time of stoppages at blow room due to maintenance and other unavoidable problems.
  • Chute feed system control short term variation but not the medium and long term variations. 
  • A reliable check on the nominal count can be established in lap forming system by controlling total lap weight and C.V. value of the weight per unit length. There is no such control in the chute feeding system. 
  • Change of mixing will result in more waste in chute feed. 
 

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