Degreasing is one of the most critical processing steps involved in sheepskin production. It is a widely accepted fact that if natural fat is not removed properly from the skins during the manufacturing process, it can give rise to a number of faults in the leather products, including the appearance of fatty spews. But fat removal is a hard job to do for any surfactant or solvent. That is why some tanners turn to enzymes.
NovoCor ADL to the rescue
Pakistan-based Leather Field is one of the largest leather and leather apparel manufacturers in Pakistan. The company produces all types of leathers such as garment, upholstery, and gloving leathers. The production output amounts to 150,000 square feet of leather per day, which is more than 3 million square feet per month. From this, 55% is small skins, such as sheep and goat, and 45% is cattle leather. Leather Field has made its mark in the leather industry by producing and selling first-rate products to international top brands in the US, Europe, and the Far East.
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| (From left:) Khalid Mehmood of Novozymes’ partner Hostachem talks high-quality leathers with Leather Field Marketing Director Suhail Ghumman. |
When Leather Field received complaints about fatty spews in its leathers, this was not taken lightly. “We pride ourselves in being a supplier of superior-quality leather apparel, so we naturally took the problem quite seriously,” says Aftab Ahmed, Chief Technician at Leather Field.
Since harsh solvents and surfactants did not do the trick, Leather Field contacted Novozymes’ Customer Solutions Manager Muhammed Arshad Gazi, who advised them to use an enzyme-assisted degreasing technology to ensure that fat removal would be consistent, efficient, and fatty spew free.
“NovoCor ADL really came to the rescue! It is the only reliable solution for us; not only can we guarantee our customers that they will not experience fatty spews any more, but the overall consistency and quality of the leather is substantially improved compared to our previous standard degreasing system. That’s a big deal to us and to our customers,” Leather Field CEO Ajmal Cheema explains.
Farewell natural fats
Enzymes have proven their worthiness in making high-quality leather. Degreasing with lipolytic enzymes (lipases) eliminates the need for harsh solvents and surfactants, and for dry-cleaning machines. They can reach a high degree of degreasing efficiency, even over 90%, and can be added at several stages of leather production, including soaking, liming, deliming/bating, pickling, as well as in posttanning processes, depending on the product. However, which enzyme to use for degreasing is very dependent on the leather. Cattle hides have different properties than small skins, especially when it comes to the level of fat content, which is why the two require different enzymes to get the right degreasing results. For small-skin leather products like Leather Field’s, NovoCor ADL is the solution.
While still an emerging technology in the leather industry, enzymes are very efficient. NovoCor ADL reacts biochemically with natural fats and hydrolyzes them into free fatty acids (FFAs) and mono- and diglycerides. That makes the fat easier to remove for the manufacturer. In contrast, the well-established surfactants simply reduce the
surface tension, which does not remove fat as efficiently and does not live up to Leather Field’s standards for fat levels.
“Whichever means we use, it’s crucial that we end up with less than 5% residual fat. That’s why we continuously analyze the hides’ residual fat content after degreasing with NovoCor ADL, and it has time and time again proved to leave only 2−4%. That’s low enough to ensure that there are no subsequent fatty spews on our leather products, and that gives us a competitive advantage that’s hard to match,” explains Aftab Ahmed.
Improved yield with a sustainable profile
For Leather Field, the switch to NovoCor ADL meant that the company’s degreasing process became more consistent. It also improved the tactile properties of the final leathers, including better softness, improved grain quality and look, and enhanced physical properties such as tear and tensile strength. “In the end, that means less damage to our leathers, which in turn means reduced trimming during leather processing. The improved yield and great quality that the enzyme achieves actually save us money and helps us both retain and attract valuable customers,” says Aftab Ahmed.
Enzymes are a sustainable alternative to chemical processing. Using lipases instead of solvents and reducing the amount of surfactants means a stronger environmental profile for Leather Field, who is currently investing heavily in its own effluent treatment plant.
The company is taking environmental responsibility and living up to the strong demands of its high-profile retail customers. By adopting an enzyme-assisted degreasing technology Leather Field has eliminated its consumption of solvents, which amounted to approximately 200,000 kilograms annually. “Enzymes basically make our degreasing process more sustainable. That matches the increasing requirements of our customers, and it’s indeed also very beneficial for the entire leather industry and the environment,” concludes Aftab Ahmed.