Dyeing to Know

Dyeing in one form or another has been with us for centuries. There is evidence that during the Neolithic period, (12,000 BC) dyeing had been used to decorate clothing and other fabrics. Back then it was a simple process of using vegetation and dipping the materials into the pulp. Nowadays with the advent of machinery we are presented with various methods of dyeing. Each one offers different advantages depending on the usage and we’re going to be looking into the varying dyeing techniques. There are two classes of dyeing. Dyes that are obtained from flowers, nuts, berries and other forms of vegetables and plants as well as from animal and mineral sources, are known as natural dyes. The other class is known as synthetic dyes. These are based on a particular type of chemical composition. Examples are: Acid (Anionic) dyes Basic ( Cationic) dyes Neutral - premetalized dyes Sulphur dyes Vat dyes Reactive dyes Pigment dyes. The dyeing techniques themselves fall into the following categories: Direct Dyeing, Yarn Dyeing, Skein (Hank) Dyeing, Package Dyeing, Warp Beam Dyeing and Space Dyeing. Many of these names may not be familiar to you and for the layman it is fair to ask the question: why so many options? The easiest way to answer this is to look briefly at what each process actually entails. Direct dyeing is a method where the dye is applied directly to the fibre. This can be done with very small or fairly large amounts of fibre depending on what utensils are available, but it is particularly good for smaller amounts. One advantage is that the fibres don't move around so there is less tangling or felting. Another advantage is that very small amounts of dye can be made up, reducing the risk of waste. Yarn dyeing is nothing more than adding colour to the yarn that has been used to create a garment or item, such as a carpet tile. Industrial yarn dyeing takes place before the product is sold, but Yarn Dyeing can also be implemented by the DIYer with the right implements after purchase. Yarn dyeing is used to create interesting checks, stripes, and plaids with different-coloured yarns in the weaving process. Skein or Hank Dyeing is used for small lots. Yarn is unwound from cokes to skeins and then mounted and immersed into a large hot dye vat. After dyeing and drying the yarn is rewound onto cones. This is a perfect method for short runs. Package Dyeing is usually employed for dyeing of yarn that has been wound on perforated cores. This helps in forcing the dye through the package. With the start of dyeing cycle, the dye goes on circulating throughout the vessel and tank. This happens till all the dye is used up or fully exhausted. This is a very mechanical process and so means considerable reduction in yarn handling. It is also suitable for large batches and, thanks to infra red technology, high temperature drying is possible which means the dye bonds exceptionally well with the material. Warp Beam Dyeing is a larger scale version of package dyeing. An entire warp beam of warp yarn or woven fabric is wound onto a perforated cylinder made of wood or metal and then placed into the beam dyeing machine. The dye is forced through the perforated cylinder from the inside out and the outside in for complete permeation. Space Dyeing utilises three colours, (any more can yield muddy looking results) which instead of being completely submerged into the dye bath, each skein is suspended so that only part of the yarn is in the bath as you dye each individual colour. This is a very precise method and is used for more intricate dyeing patterns. Most Bürofloor carpet tiles are solution-dyed. In this process, the pigments are added to the polymer before it's extruded into yarn. This means that the carpet fibres are inherently coloured, giving a far higher level of colour-fastness and durability, as well as a more even tone. For commercial contract carpet tile installations, this is unquestionably the preferred dyeing method.