The concept of biopolishing was first developed/invented in Japan. Biopolishing is a finishing process that improves fabric quality by reducing the pilling tendency and fuzziness of cellulosic fabrics. This finishing process targets the removal of small fiber ends protruding from the surface of the yarn and creates a permanent effect using enzymes. The hydrolysis action of the enzyme weakens the stretched fibers to such an extent that a small physical friction force is sufficient to break and remove them.
Biopolishing process in textile
Natural fibers used to make fabric usually contain cellulose, such as cotton, linen, ramie, viscose, and lyocell. These fibers tend to form 'fuzz' (short fibers protruding from the surface) and 'pilling'. An enzymatic process called biopolishing can eliminate or reduce fibrillation, resulting in better softness, increased volume, and a peach-skin handle.
Biopolishing can be defined as a biological way of treating textiles wet. It includes enzymatic desizing, bio-(scoring, bleaching, washing, polishing, polymer) finishing, aromatherapy, and special finishing such as wrinkle-free effect, antimicrobial finishing, deep sleep finishing, etc.
Biopolishing is a process using cellulose to modify the surface of cellulosic fabrics to reduce pilling and increase pilling resistance. It is achieved by hydrolysis of cellulose, eliminating the surface microfibrils of cotton fibers. This method improves the softness and smoothness of the fabric and the surface is less vulnerable to dirt absorption. Biopolishing of cotton using cellulose also results in 3-6% weight loss and about 10% tensile strength reduction, which is acceptable.
Development history of Biopolishing or enzyme
The textile industry accounts for about 58% of environmental pollution. Therefore, eco-friendly wet processing has become a major concern of textile manufacturers to achieve high-quality products without impacting the environment and people. The use of enzymes in textile chemical processing is gaining worldwide concern due to their non-toxic and eco-friendly properties. Enzymes were discovered in the second half of the 19th century and are routinely used in many environmentally friendly industrial sectors. Biotechnological processing of textiles offers many advantages over traditional chemical methods. Enzymes use significantly less water, less energy, and fewer chemicals than conventional methods. Additionally, residual waste from enzymatic treatment is easily biodegradable and does not pose an environmental threat.
Objects of biopolishing in textile
a. To remove stretched fibers and slubs
b. To remove hair, fluff, and pill.
c. To prevent material from sticking.
d. Fabric softens in hand and improves the handle.
e. To achieve surface smoothness a clear structural appearance and improved glow.
f. Material texture to improve relaxation and increased flexibility.
g. To improve sew-ability and fast washing, less tendency to pilling, will not nap in use, or during care operation.
h. To transform fabrics from poor quality, uneven, napped, material surfaces to top quality with bright, soft, elegant, delicate, high-quality surface appearance.
Common properties of enzymes
i. They are environment friendly and easy to treat and clean their waste
ii. They increase the rate of chemical reactions by lowering the free energy barrier between reactants and products
iii. They work under mild conditions (enzymatic treatments can save energy because they work at lower temperatures and pH)
iv. Their actions are controllable
v. They act selectively on certain substrates
vi. Their action is mainly confined to the surface.
Chemistry of biopolishing in textile
Compared to other chemical reactions, enzyme-catalyzed hydrolysis of cellulose is strongly influenced by factors such as pH, temperature, time, and agitation. The optimum pH for a particular cellulase depends on its source. Trichoderma-based products (sometimes called 'acid cellulases') work best at pH 4.5-6, whereas cellulases from Humicola (often called 'neutral cellulases') are more effective at pH 6-6.5.
The temperature of the reaction is also important because at low temperatures, the reaction rate is slower than desired, but very high temperatures can inactivate the enzyme by providing enough energy to change its molecular alignment and thereby lose its catalytic ability.
Since the enzymes are true catalysts and are not consumed during the chemical reaction, the hydrolysis reaction will continue until the reaction conditions are changed or the cellulose is physically removed from the reaction mixture. Mechanical agitation is important for the hydrolysis reaction to proceed efficiently. Recent work has demonstrated that reaction kinetics are controlled by mass transfer effects. The absorption-adsorption mechanism of enzyme action relies on movement to remove hydrolysis byproducts and open up new fiber areas for attack.
Since the physical alignment of molecules is crucial to their catalytic ability, methods that alter cellulase hydrolysis must be employed to prevent the internal formation of excessive fiber molecules to inactivate catalysis and stop hydrolysis. High temperature (>70°C), high pH (>10), and high electrolyte content as well as enzyme poisons can stop the reaction by distorting.
Environmental impact
Biopolishing or enzymes are a sustainable alternative to harsh chemicals used in the textile industry. They have unnecessary water consumption and less energy during the manufacturing process. Enzymes provide us with an eco-friendly environment and save a lot of money by reducing water and energy consumption, resulting in lower production costs.
Conclusion
The textile processing industry uses a lot of water, energy, and harsh chemicals so efforts are being made to reduce pollution in the textile industry. Biopolishing is one of the best techniques applied to reduce environmental pollution and the use of chemicals, especially in wet processing where this mixture uses a lot of water and energy. Cellulose is one of the most abundant natural organic polymers found on Earth. Cellulose fabric has floating fibers on its surface. A soft and clean fabric surface without any floating fibers is an important factor for good marketing of the garment. The most common method to have such a clean fabric surface is to remove the protruding fibers from the fabric surface. Many studies have shown that enzymatic treatment, commonly called bio-polishing, removes floating fibers from the fabric surface and improves surface properties such as bright appearance, soft feel, and resistance to pilling during washing and wear. Other benefits of biopolishing are moisture retention and moisture absorption.
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