A Comparative Study on the Performance of Lap Feed and Chute Feed System in Carding

Last Updated on 23/02/2022

A Comparative Study on the Performance of Lap Feed and Chute Feed System in Carding

Mainak Mitra
College of Textile Technology, Berhampore,
University of Calcutta

 

Introduction
Carding is the critical operation of cleaning and opening of fibers. Raw material in the form of individual fibers or at least in clusters of a small number of fibers is prevalent for desired quality of final yarn. Conventional way to feed card is lap, processed from blowroom. But a close examination of the lap reveals the following blemishes:

  1. Fibers remain comparatively in bigger size.
  2. Many of the impurities lie within the lumps of cotton due to the compression of fibers during lap preparation.
  3. Extent of opening achieved, is defeated to a great extent due to frequent compression of fibers during lap formation.
  4. Additional costs in terms of scutcher operation, lap transportation, card stoppages and lap wastages.
  5. On the other hand chute feed processes open-out cotton, directly feed to card keeping the above mentioned disadvantages at bay. But feeding the cards here has some adverse effects on the quality of the card sliver as well as the delivered material in the subsequent stages.
  6. From productivity point of view C.F carding is advantageous than that of L.F.
  7. Taking into account the advantages and disadvantages of chute feed arrangement it is expected to be worthy to study the system in details and compare its performance with that of the conventional one.

Scope of the Present Study:
In the present project it will be attempted to study the quality parameters of card slivers as well as the finished yarns made from chute feed and lap feed system in carding, maintaining the standard setting parameters on both the systems being applied on cotton materials in a controlled manner.

Card Sliver:

  • Weight regularity: by wrapping method, by Uster
  • Nep count

Finished Yarn:

  • Nep count
  • Uster and imperfection (thick, thin, neps)

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 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.

Demerits of Lap Feed System in Carding:

  • Stoppage due to lap changes.
  • Extra labor for lap transportation
  • Compression of fibers 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.
    .
lap feed system in carding
Figure 1: Lap feed system in carding

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 fibers trash particles can be removed easily during carding.
  • Suitable for synthetic fibers of bulky in nature, avoiding

Chute Feed Advantages:

  1. Irregularities due to lap licking in high humidity.
  2. Elimination of irregularities due to double laps, lap splitting, lap piecing etc.
  3. Reduction of 1% C.V in chute feed carding system.
  4. Difficulty in removing of crushed foreign materials and trash during calendering is reduced.

Experimental Procedure:
The purpose of present work with the evaluation of yarn parameters of chute feed materials by means of standardization of setting parameters in various downstream processes right from blow room to ring frame, brought about by aero feed and conventional lap feed mechanism. Various studies from cotton mixing to yarn have been made up.

Spinning Process Machineries:

Spinning process
Figure 2: Spinning process

Results and Discussion

Parameter C.F L.F
Cotton feed: gm 500 500
Waste (B/R): % 8.07 7.91
Clg effy (B/R): % 64.49 63.65
Nep genrn (B/R): % 250 186
CV  %   L-L yd-yd 1.30 0.84
Clg effy (card)  % 97.1 96.8
Uster (card) % 4.01 3.56
Count 29.6s 31.0s
CSP 1915 2340
Total imperfection 328 170
Uster (U%) 16.0 14.0
Count CV % 4.4 2.8
Nep redn (card) % 51.14 53.40
Single strength 252gm 271gm
Strength CV % 11.9 8.8
Elongation % 5.2 5.5
Tenacity (gpt) 12.6 14.3
Power involve(HP) 75 50

Discussion
From the productivity point of view chute feed spinning method is advantageous overlap feed. Lap feed process in carding is a quality oriented product whereas in chute feed to keep quality of the final material within a standard level is a difficult phenomenon.

The flow of material although the C.F line is always more or less keeps a whirling turbulance of air. This causes the fibrous material to go-around before finally reaching the licker-in zone of card and making the fibers uncontrollable. Technically speaking the primary leading hooks of the material may appear as a trailing hooks and vice-versa. Due to the tendency of all the fibrous materials to change its own direction of flow by means of different curvature of ducting of aero feed process. Apart from the changing of trailing hook and leading hook the fibrous material is specially short floating immatured one, which may turn into a ball like formation, known as Nep.

Conclusion and Summary:
It may be stated that with this coarser variety the overall level of yarn quality disapproves. As long as quality values of yarn are concerned with B/R scutcher line card system may possess an overall superior quality than compared to aero feed technology.

Suggestion for Further Work:

  • Experiment may be done with a wide range of mixing.
  • Experiment may be extended on computer.
  • Blended yarn of different mixing may be processed.
  • A detailed time oriented processing may be done.
  • Properties like stiffness, smoothness, abrasion resistance, cleanliness and moisture content may be tested.
  • Fabric properties made from these two processed materials may be examined.
  • Dye-uptake property of yarn from C.F and L.F processed may be tested.

You may also like:

  1. Carding Process in Spinning – An Overview
  2. Recent Development of Carding Machine in Spinning Mill
  3. Flats in Carding Machine: Types, Construction and Movement
  4. Carding Cylinder: Types, Features and Specifications
  5. Roller Card in Carding for Non-woven and Wool Carding
  6. Chute Feed System in Carding: Advantages and Disadvantages
  7. Neps in Carding: Major Defect in Yarn Manufacturing
  8. Doffer in Carding Machine: Types, Specification, Functions & Maintenance
  9. An Overview of Licker-in (Taker-in) of Carding Machine

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