In the industry of industrial and household dyeing, reactive dyes dominate the market. These dyes can be used for a wide range of applications. From paper dyeing, fabric dyeing, carpet dyeing, leather dyeing, and automotive dyeing, the list of applications for reactive dyes is endless. These dyes, apart from being fast to dry and easy to use, are also very versatile and have a wide range of applications.
In a simple definition, a reactive dye is a dye that contains a pair of hydrophobic carbide ligands which react with an acid to form a dye solution. Reactive dyes possess good stability properties due to the covalent bond that takes place during dyeing, making them suitable for a variety of industrial and household applications. Reactive dyes can be used to create flat finished carpets, fabrics, leather, rubber and plastics that exhibit the finest color. They are also used to produce photographic images and can even be used to substitute indigo in the printing industry.
The latest craze in the area of reactive dyes is the Synthetic Polypropylene (SPP) market. Whereas, many industrial dyes such as polyester can be saturated, many synthetic fibers cannot. This is because they do not contain any moisture, which makes it impossible to dye them. Schlaefke says that SPP provides a number of advantages over other alternative dyes. It is light weight, durable, flexible, resistant to scratching, does not fade as easily as other synthetic fibers and is readily available.
In addition, there is a lot of demand for synthetically produced fibers in the textile industry, and this is expected to grow substantially in the next few years. The rise of China as a manufacturing hub for textiles has meant an increase in demand for synthetic fibers. Demand has now reached $20 billion worldwide, and this figure is expected to increase annually. This has put textile manufacturers such as DuPont, Krome and New Holland on the bandwagon, with their RDF (resourceful fabric component) technology. These companies are leveraging their combined experience to make RDF fabrics that are more environmentally sound and capable of being woven together in intricate designs.
A major advantage of using reactive dyes is that the process of dying is minimally intrusive. Unlike with other dye-based systems, chemical dyeing requires only heat and water. There are no hot-water vapor compression cycles to extract extra moisture, no need for coolants or lubricants, and no need for solvents. All of these components mean significant cost savings, which makes dye-based systems a popular choice in the textile industry. Some of the other advantages of using dyes is that they can be tailored to a wide range of colors, which is especially helpful in apparel and protective clothing applications.
The major disadvantage of using a dye is that the molecules in cotton are too large to be able to pass through some of the most popular industrial dye processes, such as calendaring and bleaching. The dye molecules simply will not be large enough to be able to pass through most dyed cotton fibers. In addition, if the reactive dye is created using a process that involves a reaction between the chemicals that form the dye with a chemical that reacts to the heat from the dying process, the resulting color will not be the original one created by the mixing of the chemicals. Because these chemicals tend to break down over time, the final color may not be as bright as it was when the dye was created.