Preparation consists in an ensemble of cleaning processes carried out before dyeing and all necessary chemical auxiliaries.
To avoid any kind of dyeing problem (stains, haloes, lack of homogeneity, colour changes, etc.), at the beginning raw textile fibres must undergo various cleaning treatments with specific chemical additives intended to remove the various natural or synthetic impurities that may prevent the dyeing bath from penetrating and spreading into the textile substrate.
Besides removing the various natural impurities (fats – wooden impurities – extra cellulose substances – minerals, etc.) and the substances used for spinning and weaving (spin finishes – lubricants, etc.), fibres must be also bleached and made perfectly hydrophilic by means of proper preparation treatments that will vary according to the fibre to be treated and the plants made available.
The removal of the natural pigmentation allows for dyeing in light / pastel tones.
WASHING, DESIZING, BLEACHING, ALKALI TREATMENTS (alkali scouring – caustic soda process), ACID SCOURING may be used for artificial and synthetic fibres.
ENZYME DESIZING, ACID SCOURING and ALKALI SCOURING (neutral – reducing – oxidizing), BLEACHING, CAUSTIC SODA PROCESS and MERCERIZING may be used for natural cellulose fibres, such as cotton, linen and hemp.