English Views: 5 Author: Site Editor Publish Time: 2021-12-20 Origin: Site
Rieter offers solutions to integrate recycled raw materials into yarn production to help achieve a closed-loop textile cycle. Our latest research results show that not only rotor spinning can be made on the Rieter system, but also ring-spun yarns of different qualities can be spun, in which a high proportion of recycled raw materials can be used. It is economically feasible to produce blended yarns with a recycled fiber content of up to 75% (rotor yarn) and 60% (ring spun yarn).
The application with the highest demand for recycled raw materials is the blending of recycled cotton and raw cotton. Rieter determines the optimal spinning process by calculating raw material preparation and optimal machine configuration. In order to evaluate the quality, performance and optimal process steps, according to the previously defined fiber length characteristics, bleaching "post-consumer raw materials" classified as "good" are selected. This material is then mixed with 1 1/8 inch raw cotton. In the experiment, the cotton bundle mixing process is used to accurately mix the raw materials from the beginning of the spinning process to improve the operational reliability and quality of each spinning process.
The rotor spinning machine is more suitable for processing raw materials with high short fiber content (>30%), and the yarn produced is even better. This is because rotor spinning uses closed fiber transport in the fiber feed channel, and fiber consolidation is performed in the rotor. In order to obtain acceptable yarn quality and operational reliability, this raw material configuration can be blended with up to 75% recycled fibers.
Compared with the ring spinning process, the rotor spinning process not only has advantages in fiber feeding, but also can remove the small fiber neps and foreign particles in the virgin cotton fiber by means of the opening roller and the trash removal unit. As the content of recycled fibers increases, this can greatly reduce the number of neps in the rotor spinning process and enhance the advantages of rotor spinning.
Due to the yarn structure and the friction between the fibers, the spinning system has a stronger influence on the yarn strength than the recycled fiber content or fiber length characteristics in the blend. Therefore, the yarn strength of the ring spinning process is higher than that of the rotor spinning process. In rotor spinning and ring spinning, yarn strength has a linear and inverse relationship with recycled fiber content.
As the content of recycled fibers increases, the color of woven and knitted fabrics becomes lighter because the open cotton fibers are bleached. Compared with ring-spun yarn, the advantage of rotor yarn in yarn unevenness is clearly reflected in the fabric. The opening roller unit on the rotor spinning machine has a positive effect. The fabric woven from rotor yarn contains significantly fewer small foreign particles. These impurity particles produced by adding virgin cotton or not removed in the blow-out line are efficiently removed under the action of the opening roller of the rotor spinning machine.
Hairiness is directly related to the content of short fibers, so it is detrimental to abrasion resistance. This means that starting from 50% of the recycled fiber content, the wearability such as fuzzing and pilling will be reduced, especially in knitted fabrics. The yarns in woven fabrics are tighter and therefore have less impact. Nevertheless, the service life of the finished product is still shorter than that of the original product. Therefore, the advantages of using sustainable raw materials are reduced due to the shortened service life of the finished product. Since fashion products usually have a short service life, this shortcoming will not affect the end user. In terms of anti-pilling properties, rotor yarns are better than ring-spun yarns.
