What Are Enzymes and How Are They Used in Leather?
For those who aren’t aware of what enzymes are – enzymes are biological polymers that can catalyze biochemical reactions. These enzymes are included in different processes for different purposes. They are also used in the leather industry.
Leather is one of the most commonly used materials all around the world. With the technological enhancements, industries have seen a rapid growth in processes like biotechnology. These biotechnological processes occur at a low temperature and at atmospheric pressure, have a high space-time yield and many renewable ingredients Read more at NYJacket.
These technologies are frequently used in leather production through the use of enzymes, for many purposes including soaking, unhairing, bating, dyeing, degreasing, and others.
Soaking is the first step in the process. Amylolytic, lipolytic, and proteolytic enzymes. Enzymes like protease and lipase enhance the water uptake as they break down the soluble proteins present inside the matrix. This results in removal of salts, hyaluronic acid, and disperse fats and oils together with dirt and other contaminants present in the leather.
As a result, the leather is made wrinkle-free and thus loosens the scud. It enhances the opening of fiber structure and the process of soaking helps bring out the best quality of leather as it is clean and contaminant free now.
As we know, authentic and raw leather material comes with a ton of hair attached on it. unhairing is the process that removes hair and fur from the leather skin without causing any damages. There are two ways to unhair a leather piece, this might be conventional or with the help of enzymes.
Using enzymes for this method is known to be an environmentally friendly process – it reduces the chemical exposure and increases the softness and area yield. Protease is an enzyme used for this process. These chemicals are entirely in the hair attached to the leather and filters it out, thus removing the hair from the skin of the leather.
Fiber Opening Mechanism
Fiber opening mechanism is a cost-effective mechanism used to reduce the pollution load and need for water treatment. This collagen is certain by proteoglycans that contain protein and glucose which is linked by glycosidic linkages.
The enzymes that are based on fiber opening mechanisms follow a bio-processing method which is a non-chemical-based process. Carbohydrases are enzymes used in fiber opening which degrades the proteoglycans causing swelling due to the entry of water on the surface. In this process, proteoglycans are removed and results in softness of the leather material.
Bating is one of the most important steps in which enzymes play an essential role in loosening and peptization of non-collagenous skin structure via the disintegration and removal of the inter fibrillary proteins.
These proteolytic enzymes are mainly used in this process of bating and helps in removal of lime and other non-collagenous proteins that may cause cementing of the leather resulting in lack of flexibility.
In the process of degreasing, lipases are the most important type of enzyme. They specifically degrade fat and thus cannot damage the leather itself. These lipases hydrolyse not just remove the fat on the outside of the leather skin but also removes the fat from the inside of the skin structure.
When these natural fats are removed, other subsequent chemical treatments such as tanning, re-tanning, or dyeing have a better impact on the leather skin. The advantages of lipases give the leather a cleaner and better appearance. These lipase enzymes have proved to even improve the production of hydrophobic leather.
Waste from leather processing industries can cause serious health hazards and environmental problems. The only solution is to dispose of these wastes properly. The major solids waste generated at pre-tanning operations should be hydrolyzed using pancreatic enzymes.
Trimming that is obtained after liming has the alkalinity that corresponds to pH 10. This issue can be treated with alkaline protease. This process is conducted at a constant temperature i.e., 55 degrees Celsius that is favorable to the enzyme. The combination of hydrolytic enzymes like proteases, carbohydrases, and lipases can be used for this process.
Enzymes are getting more popularity due to their environmental friendliness and the fact that they are cleaner and more convenient than conventional methods. The role of enzymes in the leather processing industry is very essential. They are better than conventional processes and are environmentally friendly as well.
The study of using enzymes in industries other than leather is still in process and are hoping to find a way to replace conventional processes with procedures including enzymes.