Fundamentals of Singeing

The verb ‘singe’ literally means ‘to burn superficially’. Technically, singeing refers to the burning-off of. Loose fibres not firmly bound into the yarn and/or fabric structure;

• Loose yarns not firmly bound into the fabric structure;

• Protruding fibre ends sticking out of the textile yarns and/or

fabrics.

Textiles materials are most commonly singed in woven or knitted fabric form or in yarn form.

Fundamentals of gas Singeing

In this type of singeing machine, the fabric passes over a burning gas flame at such a speed that only the protruding fibres burn and the main body of the fabric is not damaged by the flame. This is the most common type of machine used for singeing fabrics as well yarns.

Hypochlorites Bleaching Process

Hypochlorites are salts, chiefly important as powerful oxidizing and bleaching agents; not, however, when pure, but when containing chlorides. The chief hypochlorites, or at least the complex substances which contain hypochlorites, are bleaching-powder, and the bleach liquors made with potash and caustic soda/soda.

Sodium Chlorite Bleaching Process

Sodium chlorite, anhydrous is in the form of slightly hygroscopic crystals or flakes , soluble in water.The hydrated material is in the triclinic leaflets. The chemical formula is NaClO2 , and molecular weight is 90.45.  The molecular weight of hydrated product is 144.5.

Bleaching Process of Silk

Natural coloring matters present in silk are associated mainly with sericin and hence are eliminated during degumming. The natural colouring matter of silk can be roughly divided into yellow, green and brown pigments. However the residual pigments are adsorbed by fibroin and hence silk fabrics made from yellow raw silk after degumming are not white but have a cream colour.

Bleaching Process of Wool

Wool exhibits by nature a pronounced yellow color and also on exposure to light , alkali or by microbial degradation. Commercially, wool bleaching is carried out using either an oxidative or a reductive system, or a combined oxidation/reduction process. Oxidative bleaching in the dyebath is also possible .

Textile Bleaching Process

Bleaching is chemical treatment employed for the removal of natural coloring matter from the substrate. The source of natural color is organic compounds with conjugated double bonds , by doing chemical bleaching the discoloration takes place by the breaking the chromophore , most likely destroying the one or more double bonds with in this conjugated system. The material appears whiter after the bleaching.

Scouring Treatments of Cotton, Silk, Wool and Synthetics Materials

Natural fibers contain oils, fats, waxes, minerals, leafy matter and motes as impurities that interfere with dyeing and finishing. Synthetic fibers contain producer spin finishes, coning oils and/or knitting oils, Mill grease used to lubricate processing equipment, mill dirt, temporary fabric markings and the like may contaminate fabrics as they are being produced.

Cotton Desizing Process

Desizing is the process of removing the size material from the warp yarns in woven fabrics. Sizing agents are selected on the basis of type of fabric, environmental friendliness, ease of removal, cost considerations, effluent treatment, etc.