Rieter rotor spinning machines are the ideal solution for processing short fibers and waste cotton. But which process is the ideal solution for raw materials with a high short fiber content? Furthermore, how many drafting zones should the draw frame module contain? There is a study that answers these questions for us.
Three process experiments
Figure 1: There are many production methods for rotor yarn.
To find the ideal method for processing cotton with a high short fiber content, we studied three different processes: the traditional rotor spinning process with two drawing steps; The short process of traditional rotor spinning with autoleveling draw frame; the short process of rotor spinning with carding machine equipped with autoleveling draw frame module (Fig. 1). West African cotton mixed with varying amounts of short fiber (noil) was used as raw material. The yarn counts produced are 12S, 20S and 30S. In the study, 30S yarn was knitted into single-jersey knitted fabric on a circular knitting machine to facilitate visual evaluation.
Economic short rotor spinning process with the best quality
Auto-leveling draw frame module The rotor spinning short process is an attractive solution not only because it is cost-effective, but also because quality is important (Fig. 2). Compared with processes using one or two drawing steps, this process can effectively improve yarn quality when processing raw materials with a short fiber content of 50% or higher (Figure 3). In this case, the RSB drafting system module connected directly behind the card brings the safety of controlled drafting. In addition, this solution can also improve the breaking resistance of the sliver, ultimately making the rotor yarn more uniform.
Figure 2: High and short Typical applications of fiber content rotor yarns.
Compared with one drawing process, the sliver processed by the RSB drawing module has higher adhesion. Therefore, even when processing raw materials with a high short fiber content, the cohesion of the sliver processed in the short rotor spinning process will not be reduced too much, and the adhesion can avoid uneven long segments of the yarn. This means that when processing cotton raw materials with a short fiber content of 50% or more, the yarn produced by the rotor spinning short process has better uniformity and overall yarn quality than the conventional or traditional short process spinning. Cup spinning process. This is reflected in the three yarn counts analyzed in this study.
Figure 3: The rotor spinning short process equipped with RSB module can effectively improve the processing of raw materials with high short fiber content. Yarn quality. Two drafting zones are key
The RSB drawing module plays a crucial role when processing cotton with a high short fiber content: this module has two drafting zones (Fig. 4). This effectively improves yarn evenness and ensures yarn quality even when processing pure virgin cotton with a short fiber content of 27% or higher.
Figure 4: When processing virgin cotton with a short fiber content of 27% or more, it is necessary to Use two drafting zones.
When using other solutions on the market with only one drafting zone, the yarn evenness will be significantly worse. , and it is especially obvious when processing long sliver sections. For example, the fixed weight change of 3 meters will be very large (CVm% 3 meters; Figure 5). This can lead to “streaking” imperfections in the final product.
Figure 5: When using two drafting zones, the uniformity of the rotor yarn is significant improve.
Process steps and short fiber content
When processing raw materials with a short fiber content of up to 30%, the traditional rotor spinning process with two drawing steps is the ideal solution scheme, which is mainly to improve the uniformity of yarn.
However, when the short fiber content exceeds 50%, the choice of longer process steps becomes disadvantageous. This reduces sliver adhesion, which in turn leads to lower yarn quality. For this reason, it is recommended to use a short rotor spinning process using an autoleveling and drawing module downstream of the card to significantly improve yarn evenness and reduce yarn defects. The autoleveler draw frame module in any case needs to contain two drafting zones. In this case, the RSB-Module 50 is the ideal solution.
In this study, the traditional rotor spinning short process using an autoleveller draw frame was completely unable to achieve the desired results. However, this process can be used as a compromise when the customer cannot choose the ideal process. </p