Читать книгу Sustainable Practices in the Textile Industry - Группа авторов - Страница 33

Raw textile materials are required to prepare base before processing such as dyeing and printing etc. Natural and man-made fibers contain undesirable matter like dirt or stains which are regarded as impurities. Textile materials in this “raw” state are to be “cleaned” and “finished” to make gray yarn or gray fabric.

1 a) Weighing: The weight of textile material helps us to know about the amount of soap for washing, the quality and quantity of chemicals and dye stuff to use in the mordanting and dyeing processes. Therefore, the first step is to weigh the yarn of fabric while it is still dry [57].

2 b) Soaking: Fiber or fabric is soaked for 12 h in tap water to remove the water soluble impurities.

3 c) Scouring: Fibers contain oil and fats on their surface; they are hydrophobic in nature which affects the absorbency of the fibers. The outer hydrophobic layer has to be removed before dyeing. The process by which this water resistance layer is removed from the fabric is called “Scouring”.

4 d) Bleaching: Bleaching is the process of discoloration or removal of natural and other coloring matter from fibers. This is a process of whitening fibers using oxidizing agents.