Although there are important differences, the process stages and the machines used at each stage in processing wool and cotton have similar underlying principles. Taking into consideration the necessity to cater for a continuous process, these are:
-Cleaning, blending, and completely disentangling the fibers;
-Assembly of the opened fibers into a continuous length;
-Reducing the number of fibers in the cross-section to form a strand of the required linear density or count, twisting of the strand to form a yarn, and winding the yarn onto a package.
In modern yarn manufacture, these stages may be said to translate to the following stages:
-Preparation for carding;
-Carding;
-Preparation for spinning:
-Spinning.
Carding is a process that completely disentangles the fibers, ideally separating them to the single-fiber level. It is at this stage that the web of fibers is formed into a continuous sliver.
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| A schematic of the cotton card |
A typical woolen card consists of two sections, the scribbler and the carder, each consisting of a number of cylinders.
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| The woolen card |
Man-made fibers are produced in continuous lengths by an extrusion process. Before these extruded fibers can enter the standard yarn-production process, they need to be chopped or stretch-broken into short lengths of fiber. The average length can be chosen depending on the system of yarn manufacture used for processing the particular man-made fiber. Man-made fibers usually enter the processing chain either at the preparation-for-carding stage or at the preparation-for-spinning stage. In some systems of yarn manufacture, when processing cotton and wool, there is an additional stage of combing, after carding, where a proportion of the shortest fibers and any remaining impurities are removed. Combing produces a higher-quality and more lustrous yarn.
Although the processing steps in converting fiber to yarn generally follow these stages, different methods and machine designs are required to handle the different fiber types. Furthermore, it is also possible to manipulate fibers in different ways to produce yarns with completely different characteristics. Different systems of yarn manufacture have therefore evolved. The primary systems of yarn manufacture are;
1 yorum:
textile refers to any kind material of interlacing fibres, hence textile raw materials are those fibres capable of being converted into yarn. Yarns can be produces in different sizes and texture, yarn also vary in other characteristics. Performance and end use of the fabrics are affected by these yarn characteristics.
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