Search results

The purpose of this paper is to define the relationships between the structure of multi-thread fancy yarns and the combination of the rotational speed of the hollow-spindle spinning system and thickness and stiffness of the effect component.

To do so, two groups of fancy yarns were made using stiff and soft effect threads and at six different machine settings.

It was found that the stiff effect thread was suitable to make fancy yarns at low rotational speeds, while the thickness of the effect threads was more important than its stiffness at low number of wraps. Additionally, even when using the same number of wraps and the overfeed ratio, a bouclé yarn, a gimp yarn, a wavy yarn or a loop yarn may results if the thickness and stiffness of the effect thread and the rotational speed were all controlled properly.

This study helps fancy yarn spinners to determine the type of final fancy yarns by controlling the spinning geometry in the first spinning zone.

The purpose of this paper is to define the relationships between the first spinning zone of the hollow-spindle spinning system and technological parameters of manufacturing multi-thread fancy yarn.

A simple mathematical equation was introduced to account for the effect-thread helices. The validity of this equation was tested using visual observations of the helices of the effect thread in terms of their number, width and regularity and then compared against the theoretical values.

It was found that higher overfeed ratios increased the diameter of the helices without affecting their number, while increasing the rotational speed increased their number but reduced their diameter. The effect of these changes on the fancy yarns was that higher number of helices resulted in more fancy profiles while wider helices resulted in larger fancy profiles.

This research offers fancy yarn manufacturers a better understanding of the manufacturing process of fancy yarn and its practical advantage is to help them in determining the type of the resultant fancy yarns by controlling the geometry of the first spinning zone.

The purpose of this paper is to mathematically model the structure of doubled fancy yarns made by combining together several threads.

It was assumed that such a structure may have two distinctive parts – sinusoidal and helical (i.e. sigmoidal). This model is based on calculating the length of the effect thread in relation to the core thread. The case of having several variants of such a structure was discussed to account for several types of doubled fancy yarns. The number of wraps of the binder, the overfed ratio, and heights of the fancy profiles in the different parts were the fundamental parameters of this model. The effects of changes in the number of wraps, the overfeed ratio or both simultaneously, on this model, were also considered. The shape factor of fancy yarn was also modelled depending on the basic model of the structure.

The model was tested and the correlation coefficient between the theoretical value and the real value of length of the effect thread was 0.90.

This model is useful for predicting the length of the effect component based on the type, dimension and number of the fancy profiles of doubled fancy yarn, and for understanding the changes of the multiple-thread structure of fancy yarn when the overfeed ratio and/or the number of wraps were to change.

No study was published about the tensile properties of different sections of multicount yarn. Hence there was a need to conduct a detailed section-wise tensile study of fancy multicounty yarn. The purpose of this study is to identify the different sections of the same multicount yarn and test them separately.

Multicount yarn with slubs were prepared on a ring frame with the Amsler Textile Effect System. Different yarn sections from each multicount yarn are identified as fine normal, fine slub, medium normal, medium slub, coarse normal, coarse slub and the changeover sections. These sections are tested for the breaking load and breaking elongation. Broken ends of the yarn sections are also studied, and these broken ends are classified as sharp broken end, tapered broken end and slipped broken end. A study is also conducted on the location of break or the place of break at the changeover sections.

It was found that the twist of yarn at slub sections was lower than the twist at normal sections. In spite of the low yarn twist at slub sections, the breaking load of the yarn was higher at slub sections than at normal sections by 12 to 30 per cent owing to the presence of more number of fibres that share the breaking load. The breaking load at the changeover section (normal to slub and slub to normal) was found to be higher than that at normal section and lower than at slub sections. No significant difference was found between the breaking load of the two changeover sections (normal to slub and slub to normal). The majority of breaks in normal yarn sections were of the tapered broken end type and the majority of breaks in slub yarn sections were slipped broken ends.

Efforts are taken to identify different sections of the same multicount yarn with the help of specially designed square black board and tensile study of these sections are carried out.

The appearance of a yarn is one of the most important yarn physical properties no matter it is for normal yarns, fancy yarns or the spliced yarns. As for the spliced yarns, the appearance of the splices will be used as an indicator to indicate whether the splice is acceptable or not for providing the necessary strength for further processing. When splicing the yarns under different splicer and yarn parameters, different spliced yarn appearance will be obtained. The appearance of the splices were then compared with the parent yarns and a grade (1 to 5) was then given to the splice with, 1 equals to Fail and 5 equals to Identical. The results indicated that the yarn linear density and the length of the yarn tails are the most important parameters that affect the appearance of the spliced yarn.

The use and importance of mélange yarn in apparel sector is increasing day by day. With the gradual increase in market share, achieving the desired quality level of mélange yarn remains a challenge for yarn manufacturing industry. The purpose of this paper is to investigate the effect of raw material (dyed fiber percentage in the mixing), important spinning process variable (yarn twist multiplier) and productivity (spindle rpm of ring frame) on properties of cotton mélange spun yarn.

Box and Behnken Design of experiment has been used to investigate the important yarn quality parameters like evenness, imperfection, hairiness, breaking strength and breaking elongation of blow room blended cotton mélange yarn. The quadratic regression model is used to derive the statistical inferences about sensitivity of the yarn quality parameters to the different process variables. The response surfaces are constructed for depicting the geometric representation of yarn quality parameters plotted as a function of process variables.

The study shows that shade depth and spindle speed have significant effects on the mélange yarn unevenness and imperfections. Mélange yarn strength and hairiness are significantly affected by shade depth and yarn twist multiplier (TM). Yarn elongation at break is only influenced by the spindle speed. A darker shade is responsible for higher yarn unevenness, imperfection, hairiness and lower yarn strength. A higher spindle speed is also liable for deterioration of yarn quality.

Many spinning industries are planning to convert their existing spindles from normal gray yarn production to mélange yarn manufacturing. The outcome of this study will lead to achieve better mélange yarn quality and productivity by the industry.

Research on mélange yarn is itself scant. This study is exclusively conducted to analyze the individual and interactive effect of various process parameters on the mélange yarn quality.

The main objectives of this research work were to investigate the effect of production speed on intermingled yarn properties and melange fabric properties with special reference to melange appearance.

Polyester/nylon intermingled yarns were produced using an SSM DP3-C air-intermingling machine using commercial process parameters and Heberlein P212 nozzle. Melange fabric samples were knitted from polyester/nylon intermingled yarns while maintaining the same parameters to avoid knitting variations. The fabric samples were dyed using a sample dyeing machine while maintaining dye recipe and dyeing parameters constant to avoid dyeing variations.

The production speed has significant effect on intermingled yarn and melange fabric properties. When the production speed is increased, mingle points, mingle stability, linear density, strength and the elongation of the intermingled yarns decreases. When the production speed is increased, fabric weight decreases and the melange effect varies from dot-like appearance to line-like appearance.

Only the effect of production speed on intermingled yarn and melange fabric properties is discussed in this paper. Appearance evaluating systems developed in this research are limited to melange fabrics produced using air-intermingled yarns with two colour components.

Results indicate that the intermingled yarns for the application of melange fabrics should be developed with optimum intermingling speeds, and it should not be changed during the production since production speed has significant effect on yarn and fabric parameters. Therefore, melange appearance and fabric weight may vary between fabric lots with different production speeds even though all the other parameters are kept constant. Further, melange appearance evaluation method developed in this research could be used as a guide in developing melange fabrics.

This research introduced a qualitative and a quantitative method to analyse melange fabric appearance. This melange appearance evaluation method can be used as a guide to achieve specific melange effect in the sample development stage. Further, when a melange sample appearance catalogue is developed for all the variables for a particular fabric type using this evaluation method, customer requested appearance can be achieved in minimum sample trials which save time, capacity, money and customer credibility.

This study aims to investigate the effect of process parameters of blow room machines on openness degree and quality of cotton tufts in a blow room.

For this purpose, an experimental Box–Behnken design (BBD) was used, and the process parameters were the angles of the grid bars underneath the opening rollers of CVT3 beaters and the distance between feed roller of the first opening roller of CVT3.

It was found that the cotton tuft openness increased by increasing the angles of grid bars and by decreasing the distance between the feed roller and first opening roller on CVT3 beater. Further, the optimization procedure showed that an optimum value of cotton tuft openness (in laser method) was determined for specific levels of the process parameters.

The originality of this investigation is that it showed the individual effects and interactions of the most important factors in two tufting machines instead of only one machine. This study is important because it helps cotton yarn spinners to improve the quality of the final yarns by optimizing the levels of tuft openness which in turn improves fiber cleaning.

Fancy multicount yarn (9.5s Ne) is prepared on a ring frame with an Amsler fancy yarn attachment per the Box-Bhenken design for three variables and at three levels. The ring frame process parameters selected are spindle speed, traveller mass and twist multiplier. Different yarn properties, such as yarn tenacity, breaking elongation, yarn irregularity, yarn hair index, imperfections and thin places -40% are tested. An analysis of the result is done by using statistical software. It is observed that a 9000 rpm spindle speed with a 5 twist multiplier gives maximum yarn tenacity, a 9000 rpm spindle speed with traveller mass of 120 mg gives minimum yarn irregularity and traveller mass of 120 mg with a 4.8 twist multiplier gives minimum yarn imperfections within the experimental zone explored.

Grey cotton fibers with a mean fiber length and fineness of 29 mm and 4.2 micronair was pretreated, scoured and dyed. Three ring yarns were spun separately from 100% grey cotton (R.R.Y.), 50% dyed and 50% grey cotton blend (M.R.Y.) and 100% dyed cotton (D.R.Y.). The extent of fiber damage was assessed by measuring the length and the mechanical characteristics of cotton fibers after passing the fibers through the lap machine and the draw frame II. Properties of R.R.Y., M.R.Y. and D.R.Y. samples were examined. In terms of tenacity and elongation at break, grey and dyed cotton fibers, which were selected after being processed by the lap machine and the draw frame II, were very similar. The fiber length by number and weight of grey cotton was longer than that of dyed cotton, while the amount of fiber nep and short fiber content of dyed cotton were more than those of grey cotton.

The three yarn samples were the same in terms of elongation at break. The tenacity of R.R.Y. was the highest but the yarn sample was the lowest in terms of coefficients of mass variation (Cv%), imperfection and hairiness in comparison with the M.R.Y. and D.R.Y. samples.