Textile industry

We all know various sorts of fabric fibres. The variety is huge, ranging from natural fibres to man-made fibres. Natural fibres are divided into cellulose fibres (mainly wool and flax, but also jute, hemp, and others) and amino acid fibres (wool and silk). Man-made fibres or synthetic fibres are divided into

semi-synthetic and fully synthetic fibres. Naturally untreated materials are used in the manufacture of semi-synthetic fibres (artificial silk, artificial silk acetate), but fully synthetic substances (polyester, polyamide, acrylic, lycra) are made from chemically untreated substances.

Modern fabrics are usually manufactured from a mixture of fibres (polyester/cotton, polyamide/cotton, polyester/wool etc.), which may be in different proportions: 50/50, 70/30, 30/70 etc. All fibres are dyed. The dyeing process depends on the physical shape of the textile product (yarn, fabric, fibre fabric etc.). Yarn is always processed in water while fabric can be processed in many other ways. The temperature, at which the yarn is processed, may affect the amount of salt required. In continuous processes in dry air or saturated vapour, the usual temperature is 125°C.

In most cases, the required water has to be softened because metal ions can affect the final colour in the dyeing process. Therefore, salt is added during the dyeing process. The highest salt consumption is required in the dyeing of natural fibres. In order for the colour to be pure and even, the salt to be used must be pure, without impurities.

Functions of salt in the textile industry

• In textile production, salt acts as an electrolyte in the process of dyeing fabrics and yarn, increasing the intensity or depth of the dye. How much of the dye will remain in the fibre depends on the quality of salt.
• Salt softens water. When using hard water, the colour of the products is uneven and the products may be stained.

The benefits of using our salt

Depending on the price, sodium sulphate may also be added during the softening of water and the dyeing process, noting that the same amount of salt is then needed. Dye manufacturers argue that a smaller amount of salt is then needed in the dyeing process. After dyeing, the salt content in the dye solution is approximately 2%. However, many other products, such as surfactants, dyes, soda, are added, and they pose problems and re-use of salt is not possible. Therefore, a lot of salt is used in the dyeing process in the textile industry. A new salt solution must be prepared for each dyeing process.