The carding cycle affects the sliver quality and the subsequent yarn attributes since it is the main sliver formation step. Processing parameters assume a significant part in affecting the nature of the eventual outcome in any sorts of production. In the case of carding machine, a higher production rate makes the operation more sensitive. And this will cause degradation in product quality. So optimization of speed is the talk of the town in spinning field [1]. Extreme higher speed can prompt fiber harm and unnecessary neps generation will corrupt the end result. Again lower speed will lessen the production rate which isn’t reasonable. So we need to discover the ideal speed which will be advantageous to both product quality and production rate. In carding machine, real operational activity happens between flats and cards [1]. From an ordinary perspective, high produce able cards generates higher level of speed. Speed of the cards impacts the carding cycle and the nature of the yarn and in practical point of view, flat’s level of speed is advanced and optimized. The aim of the project was to find out the optimum flat speed in the context of yarn quality. 40 Ne cotton yarns were produced with the slivers manufactured at different flat speeds such as 240, 260, 280, 300 and 320 mm/min. The quality parameters of slivers and yarns were tested and analyzed.
Since carding is a complex operation—it includes a number of parameters and factors—and grasps unique advancements, improvement of the carding efficiency has been made conceivable by the improvements in some scientific fields, for example, hardware, materials science, robotization and control.
These improvements permit a few different ways for expanding carding profitability. The carding quality is essentially decided in the region of the cylinder. Here, the circulating flat is of specific significance. With an ideal number of level bars, it is liable for cleaning just as extricating neps and short filaments. This occupation is doled out to the pre-checking region with its cleaning and checking components. As a regulation: The higher the pre opening, the more intensive the carding operation, which results in expanded production. The motivation behind speedy carding is to expand the card efficiency without diminishing operation quality, or even improving it. It had been believed that increased carding speed would expand fiber breakage, however there is no proof why fiber breakage should be enlarged as card speed expands (Atkinson, 1986) [
Carding activity can be depicted as the combing of fibers between successive surfaces, which convey a number of angular wires (card clothing) focused on restricting headings, opposite direction when their relative speed is more prominent than zero. What individualizes the fibres and offers parallelism to the fiber mass flow is the connection between the saw-tooth cloth covering of cylinder, the flats/laborers furthermore, the fiber mass (Lawrence, et al., 2000) [
In compact spinning, the filaments are compacted into a hollow sliver after a basically pressure free drafting operation inside a compacting zone and they are twisted after the pinching point as a reduced intensified sliver. As in the exemplary spinning triangle, fringe filaments are exterminated. In the current work, the influence of the speed of flat of the quality of final yarn was studied. Research works have been carried out time to time on the influence of different parameters over the sliver and yarn quality. Nadim Hossain, et al. [
In compact spinning, the filaments are compacted into a hollow sliver after a basically pressure free drafting operation inside a compacting zone and they are twisted after the pinching point as a reduced intensified sliver. As in the exemplary spinning triangle, fringe filaments are exterminated. In the current work, the influence of the speed of flat of the quality of final yarn was studied. Research works have been carried out time to time on the influence of different parameters over the sliver and yarn quality.
Commonwealth of Independent States (CIS) cotton originated from Uzbekistan was utilized as the raw material to plan tests of sliver and yarn. The raw cotton fiber properties were tested with the assistance of USTER EVENNESS TESTER-5 and USTER AFIS PRO 2 as per the standard testing conditions appeared in
In this experiment, the flat of carding machine (TC 03) was driven at five different speeds, that is, 200, 240, 280, 320, and 360 mm/min, by keeping all other parameters unchanged. The process parameters of the carding machine are given in
A ring outline machine, named Lakshmi, was utilized for creating yarn. Ne 40 checked yarn was created from Ne 0.70 wandering. In ring frame, roving was placed on same shafts for every flat speed. Significant cycle parameters for the spinning procedure are provided in
| Properties | Value |
|---|---|
| Raw material | 100% cotton |
| Staple length | 29 - 30 mm |
| Micronaire | 3.8 |
| Raw material origin | Uzbekistan |
| Technical Data | Settings | Technical Data | Settings |
|---|---|---|---|
| Sliver hank | 340 - 465 grain/6 yds. | Feed roller to taker-in | 0.65 mm |
| Feed roller diameter | 100 mm | Taker-into cylinder | 0.22 mm |
| Taker in diameter | 172.5 mm | Back stationary flat to cylinder | 0.55 mm, 0.55 mm, 0.45 mm |
| Taker in speed | 1162 rpm | Revolving flat to cylinder | 0.30 mm, 0.275 mm, 0.25 mm, 0.25 mm, 0.20 mm |
| Taker in PPSI | 1) 34, 10˚ | Front stationary flat to cylinder | 0.55 mm, 0.55 mm |
| 2) 163, 10˚ | Cylinder to doffer | 0.125 mm | |
| 3) 210, 10˚ | Doffer. to take of Roller | 0.15 mm | |
| Cylinder diameter | 1287 mm | Take-off roller to delivery roller | 0.25 mm |
| Cylinder speed | 561 rpm | Delivery speed | 190 m/min |
| Cylinder PPSI | 950, 40˚ | Doffer dia. | 700 mm |
| No. of flats | 84 | Doffer PPSI | 483, 30˚ |
| No. of flats in action | 30 | Doffer speed | (Around 180 m/min) |
| Flat PPSI | 525, 5˚ | Flat speed | 240, 260, 280, 300, 320 mm/min |
| Name of the Parameters | 40 Ne Yarn |
|---|---|
| Drawn sliver hank | 0.12 Ne |
| Roving hank | 0.9 Ne |
| Twist per inch | 22.35 |
| Ring frame speed (RPM) | 17,500 |
| Drafting arrangement (ring frame) | 3 over 3 |
| Draft (ring frame) | 44.44 |
| Doubling (breaker draw frame) | 6 |
| Doubling (finisher draw frame) | 5 |
The flat speed variation has an effect on the end product. Short fibres content, sliver unevenness, yarn unevenness properties, thin places, thick places, neps, hairiness and yarn strength are influenced by the flat speed.
Neps: A NEP can be defined as a small knot (or cluster) of entangled fibres consisting either entirely of fibres (i.e., a fibre nep) or of foreign matter (e.g. a seed-coat fragment) entangled with fibres. Neps are created when fibres become tangled in the process of harvesting, ginning and other operations [
Neps content is measured in AFIS. The unit of neps content is neps content per gram in the material.
The proportion of neps has an extremely great influence on the parameters:
Yarn strength, yarn evenness, yarn hairiness and handle of the product.
Neps Removal Efficiency (NRE%): The neps removal efficiency depends on the neps fed to the card. If we feed more neps, then the neps removal efficiency shall be high. What is more important is the neps level in the outgoing material [
Neps removal efficiency = Neps content of card mat − Neps content of card sliver Neps content of card mat × 100 %
Short Fibre Content by Number: The short fibre by number is the percent of all the fibres in a cotton sample that are normally shorter than 0.5 inches or 12.7 mm [
Spinning limit, yarn strength, yarn evenness, handle of the product, yarn hairiness, productivity, neps.
Unevenness: Unevenness deals with the variation in yarn fineness. This is the property, commonly measured as the variation in mass per unit length along the yarn. For a complete analysis of the quality of fibre assembly, along with mass diagram, a numerical value of mass variation is also necessary. Mathematically it is done by The irregularity or unevenness (U%) and the co-efficient of variation (CV%) [
Imperfection Index (IPI): Imperfections are considered as frequently occurring faults and are dependent on the fibre quality of the raw material. The conditions of the production machinery strongly influence the amount of the imperfections in the yarn. The total imperfection of a yarn is simply expressed by imperfection index (IPI). The sensitivity settings for the detection of imperfections are −50%/km for thin places, +50%/km for thick places and +200%/km for neps [
Count Strength Product (CSP): It is a number which is derived by multiplication of count & lea strength (in lbs.). The higher value represents the better yarn strength.
i.e. C.S.P. = Strength of yarn in pound (lbs.) × Count in English system (Ne) [
The left graph of
By observing the graph, we can say that the variation in the flat speed has an effect on the variation of the neps content per gram of card sliver. When flat speed is increased, more number of flat comes to the contact with fibre treatment operation. So the increase of flat speeds reduces the neps content per gram in the card sliver.
In the graph, we see that at flat speed 240 mm/min neps content per gram was
90 whereas at flat speed 320 mm/min neps content per gram was 71. So we may conclude that with the increase of flat speed neps content per gram of card sliver is reduced.
Second graph of
In the graph, we see that at flat speeds 240 mm/min, 260 mm/min, 280 mm/min, 300 mm/min and 320 mm/min, the NRE% are 66.56%, 67.89%, 68.87%, 72.24% and 75.92% respectively which is an increasing trend.
From the graph, we can say that the variation in the flat speed does have an effect on the variation of the NRE% of card sliver. When flat speed is increased, more number of flat comes to the contact with fibre treatment operation. So the increase of flat speeds leads to increase in the NRE% of the card sliver.
The above left handed graph of
Short fibres can only be eliminated if they are pressed into and retained in the clothing. Only the flats can be considered in this context. Short fibres offer less surface to the clothing of the main cylinder, they therefore remain caught in the flats clothing, are pressed into it and leave the machine in the flat stripping. As the flat speed is increased, more numbers of flats are cleaned of adhering short fibres by fast rotating brushes.
It may conclude from the graph that the variation in the flat speed has an effect on the short fibre content of card sliver and it shows a decreasing trend.
The above right sided graph of
From the graph, we see that at flat speed 240, 260, 280, 300 and 320 mm/ min the corresponding nep count of card sliver are 10, 5, 4, 3 and 1 respectively which is a decreasing trend. The increase of flat speed increases the finer neps content.
From
From the graph, it was observed that at flat speed 240, 260, 280, 300 and 320 mm/min the corresponding U% of card sliver are 3.56, 3.01, 2.71, 2.51 and 2.14 respectively which is a decreasing trend.
The increase of flat speed reduces the neps content and short fibre content. Therefore the degree of parallelization of fibre becomes higher because of better carding action also take place. Hence, the increase of flat speed reduces the irregularity of card sliver.
The graph shows that with the increase of flat speed the irregularity of card sliver marginally decreases.
In the second graph of
The increase of flat speed reduces the neps content and short fibre content. Therefore the degree of parallelization of fibre becomes higher because of better carding action. Hence, the increase of flat speed reduces the irregularity of card sliver.
From the first part of
Second part of
Hence, it can be said that the increase of flat speed reduces the co-efficient of variation of yarn.
In the first graph of
We know that the amount of short fibres and neps content are proportionally related with the quality parameters of yarn (CV%, thick places, thin places, neps and strength). Graphs for short fibre content and neps content showed less
removal of neps and short fibres at flat speed 240 mm/min than 320 mm/min. As a result, less removal of short fibres and neps at flat speed 200 mm/min are mainly responsible for higher number of thick places where as flat speed 320 mm/min gives minimum number of thick places due to removal of higher number of short fibres and neps.
In the second graph of
We know that the amount of short fibres and neps content are proportionally related with the quality parameters of yarn (CV%, thick places, thin places, neps and strength). Graphs for short fibre content and neps content showed less removal of neps and short fibres at flat speed 240 mm/min than 320 mm/min. As a result, less removal of short fibres and neps at flat speed 200 mm/min are mainly responsible for higher number of thin places where as flat speed 360 mm/min gives minimum number of thin places due to removal of higher number of short fibres and neps.
In left sided graph of
It is evident that at flat speed 240 mm/min the numbers of the neps are higher and at 320 mm/min the numbers of neps are lower. A decreasing trend of neps +200% is found with the increase of flat speed.
The second graph of
The graph shows a decreasing trend of IPI with the increase of flat speeds of carding machine.
The decrease in total yarn imperfections with the increase of flat speed can be explained by amount of thick places, thin places and neps of yarn.
In
By this project work, the actual relationship between the flat speed and the yarn quality was studied. From the graphical representations, it may be concluded that with the increase in flat speed of card, more neps and short fibres are removed that results lower unevenness of card sliver. The quality of card slivers directly reflects the quality of yarns such as decreasing unevenness, imperfections and increasing the strength. The quality of yarn improves with the increase in flat speed and in this work, the highest flat speed i.e. 320 mm/min is the optimum flat speed. There may be an optimum flat speed higher than 320 mm/min after that yarn quality will start to decrease. Since we were restricted to use maximum flat speed at 320 mm/min, so obtaining optimum flat speed may be the topic of further research.
The authors declare no conflicts of interest regarding the publication of this paper.
Sayed, Z.B. Afrose, N. and Kabir, S. (2021) Impact of the Speed of Flat of a Typical Carding Machine on the Quality of Carded Sliver and 40 Ne Yarn. Journal of Textile Science and Technology, 7, 66-76. https://doi.org/10.4236/jtst.2021.71006