Carding Process in Spinning – An Overview
Sikander Anwer
Department in Textile Engineering
University of Management and Technology, Lahore, Pakistan
Email: 111811016@umt.edu.pk
Introduction:
“Card is the heart of the spinning mill” and “well carded is half spun” are two proverbs of the experts. The main object of the carding process is to individualize the fibers and convert the fibres into a strand called the sliver. Carding is one of the most important operations in the “spinning process” as it directly determines the final features of the yarn. High production in carding to economies the process leads to reduction in yarn quality. Higher the production, the more sensitive becomes the carding operation and greater danger of a negative influence on quality. The technological changes that has taken place in the process of carding is remarkable. Latest machines achieve the production rate of 60-100Kgs/hr, which used to be 5-10Kgs/hr, upto 1970.
The Purposes or Objectives of Carding:
The carding is the first machine in the spinning preparation that delivers a sliver. The main objectives of the card are:
- To open the flocks into individual fibers.
- Cleaning and elimination of impurities.
- Reduction of neps.
- Elimination of short fibers.
- Fiber blending.
- Fiber orientation.
- Sliver formation.
Parts of Carding Machine:
- Feeder Hopper
- Linker in Cylinder
- Drum / Cylinder
- Revolving Slates
- Brushing Rollers
- Doffer
- Drawing Unit
- Trumpet Guide
- Grid Roller
- Sliver Cane
Technological Points in Carding:
There are two types of feeding in the cards:
- Feeding material in the form of scutcher lap.
- Flock feed system (flocks are transported pneumatically)
Carding Process in Spinning:
Point to back action:
Taker In:
Linear density of the lap is very good and it is easier to maintain (uniformity) the whole installation is very flexible deviation in card output will be nil, as laps can be rejected. Lap run out is an additional source of fault, as it should be replaced by a new lap. More good fibers loss during lap change more load on the taker-in, as laps are heavily compressed. This is opened in it and pass through small grids on it.
The purpose of taker-in is to pluck finely opened flocks out of the feed batt, to lead them over the dirt eliminating parts like mote knives, combing segment and waste plates, and then to deliver the fibers to the main cylinder. In high production cards the rotational speed ranges from 700-1400.
Point to point action:
Cylinder:
The cylinder get opened with sharp teeth and then pass over to doffer. High performance in carding due to high degree of openness of feed web. Cylinder is located below the plate is pressed against the cylinder by spring force.
Brushes:
The cotton fibers that are on the teeth of cylinder are then cleaned by the brushes at the upper part of cylinder.
Revolving Flats:
The fiber batt runs downwards without diversion directly into the teeth of the taker-in which results in gentle fiber treatment. This helps to reduce faults in the yarn. The revolving flats revolve the brushes on it, so the cotton on the cylinder teeth will eliminate the impurities.
Back to back action:
Doffer:
The doffer take the cleaned cotton same way to cylinder from taker in, and passes to drawing unit.
Drawing Unit:
The drawing unit stretched and parallelize the cotton and changes into individual fiber form, then pass to trumpet guide.
Trumpet Guide:
The straightened fiber collectively gets in trumpet guide and intermix in it to form a sliver.
Sliver Cane:
The sliver cane stores the sliver in it for further processes.
You may also like:
- Recent Development of Carding Machine in Spinning Mill
- Flats in Carding Machine: Types, Construction and Movement
- Carding Cylinder: Types, Features and Specifications
- Roller Card in Carding for Non-woven and Wool Carding
- Chute Feed System in Carding: Advantages and Disadvantages
- Neps in Carding: Major Defect in Yarn Manufacturing
- Doffer in Carding Machine: Types, Specification, Functions & Maintenance
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. He is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
It was great to read this article on the process of carding, which is the most important process in the spinning mills determining the quality of the final yarn produced. It was very interesting to read the various detailed steps that goes behind before the final yarn production. Thank you for providing this useful resource!
Looking fwd to more of your posts.