# Fabrication of Low-Twist and High-Strength Metallic Fibre Hybrid Spun Yarns
## 2 Materials and Methods
\begin{table}
\begin{tabular}{p{142.3 pt} p{142.3 pt} p{142.3 pt}} \hline \hline
**Spinning Method** & **Illustration** & **Description** \\ \hline Conventional ring spinning & On a conventional ring spinning frame, one roving is attenuated into yarn at one spinning position followed by the operations of twisting and winding. Due to the broader width of drafted roving over yarn, a spinning triangle is formed at the exit of delivery rollers, which affects control over edge fibres of drafted strand and their integration into yarn. \\ Compact spinning & On a compact spinning frame, one roving is drafted into yarn at one spinning position in the case of plain yarn. The drafted fibres are condensed to a narrow width before twisting into yarn, thereby reducing the size of the spinning triangle and providing better control over edge fibres integration into yarn. The yarn produced exhibits lower hairiness and higher tensile strength. \\ Compact SIRO spinning & In this technique, a compact yarn ring spinning machine (Rieter K44), additionally upgraded with a SIRO yarn device, was used to produce the SIRO-Compact yarns. Two rovings were fed side by side to each drafting unit, so that they are drafted in parallel. At the exit of the delivery rollers, the drafted and slightly pre-twisted strands, forming a V shape form, are finally twisted together into the yarn, known as SIRO yarn. \\ \hline Ring twister & It is a method of combining two or more ring-spun yarns by twisting them together, usually in a direction, opposite to the direction of twist in component yarns. It is also known as a down twisting technique of plied yarn. The yarns produced are considered to be smoother, stronger and softer. \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Brief description of spinning techniques. component yarns were performed simultaneously on the ring twister with the direction of a folding twist (S) opposite to that of a single yarn twist (Z). The folding twist and spindle speed were set as 8.5 turns per inch and 6000 rpm, respectively. The detailed parameters of conventional ring spinning and ARSTs are given in Table 4.  
All the yarn samples were conditioned before testing, according to ASTM D 1776 [28]. The tensile properties were tested using Uster Tensorapid, according to ASTM D2256 [29]. The hairiness S3 (The number of fibres longer than 3 mm) of compact yarns were tested using the Zweig \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Parameters** & **PS1-PS5** & \begin{tabular}{c} **PS 08** \\ **NCP** \\ \end{tabular} & \begin{tabular}{c} **PS 09** \\ **CP** \\ \end{tabular} & \begin{tabular}{c} **PS 10** \\ **NCS** \\ \end{tabular} & \
\begin{tabular}{c} **PS 11** \\ **CS** \\ \end{tabular} \\ \hline \hline
\begin{tabular}{c} Roving count (Ne) \\ \end{tabular} & 0.75 & \multicolumn{4}{c}{0.756} \\ \hline No. of roving feed per spindle & 1 & 1 & 2 \\ \hline Break draft & 1.6 & \multicolumn{4}{c}{1.24} \\ \hline TC & 2.3, 2.8, 3.3 & \multicolumn{4}{c}{2.3} \\ \hline Spindle speed “V” (rpm) & 6500 & \multicolumn{4}{c}{6500} \\ \hline Total draft & 10.5, 29, 30.7 & 13.9 & \multicolumn{4}{c}{26.7} \\ \hline Distance clip (mm) & 2.8, 2.4, 2.1 & \multicolumn{4}{c}{5.0} \\ \hline Bottom roller distance of & \multicolumn{4}{c}{48} \\ front-draft zone (mm) & \multicolumn{4}{c}{52} \\ \hline Bottom roller distance of & \multicolumn{4}{c}{58} \\ back-draft zone (mm) & \multicolumn{4}{c}{} \\ \hline Pneumatic compaction & N.A & Inactive & Active & Inactive & Active \\ \hline Traveller number & 8n0, 3/0 & 8 No. & 8 No. and 14 No. & 8 No. and 14 No. \\ \hline ISO traveller weight (mg) & 125, 45 & 125 & 125 and 250 & 125 & 125 and 250 \\ \hline \hline \multicolumn{4}{c}{**Atmospheric Conditions**} \\ \hline Relative humidity (\%) & \multicolumn{4}{c}{65–68} \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Process parameters of conventional ring spinning and ARSTs. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline