فارسیWhat is a buffer?
A buffer solution, or simply a buffer, is a mixture of a weak acid and its conjugate base (usually in the form of its salt), or, conversely, a weak base and its conjugate acid.
Buffer solutions resist changes in pH when a strong acid or a strong base is added. Because of this property, they can be used to maintain a stable pH in a solution, regardless of the type of solute present. In fact, buffer solutions are commonly used as a tool to control the pH value in most chemical processes.
Each buffer solution has its own effective pH range and can resist a certain amount of added acid or base without a significant change in pH; this ability is called buffer capacity. In industry, buffers are used in various processes, especially fermentation and dyeing.
Controlling pH is crucial for textile companies because it plays a key role in the quality of each process, including scouring, bleaching, dyeing, washing, reduction, finishing, printing, and more.
The buffer recipe
Buffers are mixtures containing a large amount of a weak acid or weak base along with their conjugate pairs (salts). A weak acid and its conjugate base can coexist in solution without neutralizing each other, and the same applies to a weak base and its conjugate acid.
Buffers can be classified into two groups:
- Acidic buffers
- Alkaline buffers
For more information about the product click on the acidic buffer and alkali buffer.
Acidic buffer
Acidic buffers are non-volatile and, as their name suggests, are used in acidic environments. Their pH is acidic, and they are made from a mixture of a weak acid and the salt of a strong base.
Acidic buffers are applied in textile industry in order to adjust the pH or neutralizing the alkaline condition after dyeing, scouring and bleaching processes. They are also used in polyester dyeing, which mostly takes place in acidic conditions. Adjusting the pH with buffers can significantly improve dyeing and neutralization processes.
Alkaline buffer
As discussed, alkaline buffers are mixtures of a weak base and its salts. These solutions are mainly used in alkaline conditions to prevent changes in pH.
In the textile industry, alkaline buffers are used in the reactive dyeing process to create and maintain an alkaline environment. The reaction between reactive dyes and cotton fibers is nearly impossible without an alkaline environment. An alkaline pH is essential for the fixation of colors onto fiber surfaces.
Alkali buffers are a suitable and cost-effective alternative to sodium carbonate. Their required dosage in padding systems and dyeing processes is significantly lower, which enhances efficiency and improves dyeing results. Moreover, the high efficiency of these buffers helps improve dye fastness, fabric depth, and color uniformity by preventing sudden pH changes and maintaining stable alkaline conditions throughout the dyeing process.
These buffers are a suitable alternative to caustic soda with low dosage and cost-effective which are mostly use in scouring and bleaching raw fabrics. These buffers are a suitable, cost-effective alternative to caustic soda, requiring a lower dosage and commonly used in scouring and bleaching raw fabrics.
Alkali buffer liquid can be easily diluted in water at room temperature and is compatible with automation systems, which is an advantage over alkali powders.