LEATHER MADE OUT OF CACTUS by Dr. N. N. Mahapatra

LEATHER MADE OUT OF CACTUS

Dr.N.N. MAHAPATRA

Business Head (Dyes) Shree Pushkar Chemicals & Fertilisers Ltd., Mumbai

Plant-based leather alternatives are a growing market, with innovators turning to pineapple, olives, and coconuts to produce eco-friendly materials. Earlier this year one of the leading brands unveiled a vegan jacket made from pineapple leather, while another launched a product of leather shoes made from olive leaves. Very interesting another local south India manufacturer came out with leather and accessories made from coconuts.

With growing awareness of the effects of the leather industry on the environment and animals, the market for cruelty-free alternatives will keep growing. So many brands are out there, trying to make vegan leather as lowimpact as possible by using plants to create leather-like fabrics. Two factories in Mexico have developed durable vegan leather from cactus, and it could very well replace animal leather. Initially, all vegan leather was made of plastic-based materials. Later on due to further research in the last few years, textile scientists have discovered many ways to make vegan leather out of everything easily available from pineapples to cactus leaves to flowers. The vegan leather industry has come up now leaving aside the good old leather and coming out with some exciting plant-based leathers on the market. Very interesting every vegan leather is made from a plant, but unfortunately, none of them are fully biodegradable yet. That is because each material is either made with a mixture of plants and polyurethane or is plant-based and coated with a plastic-based resin. While there are a few brands already selling fully compostable sneakers, no one has been able to come out with compostable vegan leather shoes yet. But the good news is, most of the brands are finetuning towards perfecting their respective vegan leathers to make their shoes biodegradable. It is well known Vegan leather has always a lower impact than animalbased leather, whether it is plant-based or completely synthetic. Not only does vegan leather leave animals out of the picture, but the process of manufacturing like breeding, raising, and killing animals and tanning leather has a high environmental impact. To raise animals (typically cows) for leather requires large amounts of land, water, and cattle feed, the animals emit methane into the atmosphere; and the excrement from cattle bodies and factory farms pollutes the nearby waterways, soil, and air, which becomes a public health risk for people who live nearby. The manufacturers had previously made vegan leather from a mix of polyurethane and bio-oil. The bio-oil is sourced from cereal crops that were organically grown in northern Europe in a carbon-neutral process. The manufacturer is trying to stop using polyurethane to make its vegan leather and recently planning to come out with a new product using viscose made from eucalyptus bark. It has been found that all the major vegan leather manufacturers make vegan leathers made from plants but also contain polyurethane in their composition, usually in their finishing or as the backing material. It was a required component in the production. Later on, people are thinking of a 100 percent biodegradable vegan leather technology that does not exist to exclude polyurethane totally but time is not far the researchers have developed a vegan leather made from nopal cactus leaves which are organic, partially biodegradable, soft, and durable which can be used to make furniture and car interiors in addition to fashion items like wallets, purses, and shoes. The scientists named Adrian Lopez Velarde and Marte Cazarez came together to create a cruelty-free alternative to animal leather, and just last month, they developed the first time an organic leather made entirely from nopal or prickly pear cactus which they name as “ Dessert “. They want to sell Desserto fabric to other designers and fashion brands, rather than design and sell their products. These nopal cactus grow in abundance across Mexico without requiring any water called a lowimpact crop. Cactus leather is a sustainable leather alternative made from Opuntia Cactus (also known as Nopal) that has been developed in Mexico. It is called Desserto and is a highly sustainable plantbased vegan leather made from cactus having superior softness to touch and great performance for a wide variety of applications and complying with the most rigorous quality and environmental standards. Developed by two entrepreneurs from Mexico who used to work in the automotive and fashion industries where they found strong environmental impact in both sectors it is concluded this vegan leather aims to

offer a cruel-free and sustainable alternative, without toxic chemicals, phthalates, and PVC.

Production of Vegan Leather

It is one of the world’s most popular and heavy demand products where leather is part of an overwhelming $80 billion industry. Thanks to these two innovative entrepreneurs for developing a method of converting cactus into vegan leather which is so realistic to look and feel you would never imagine it was made from this desert plant. They have named their cactus vegan leather Desserto, and it is made from cactus grown on their plantation in the city of Zacatecas situated in Mexico. The cactus as a plant is having rugged, thick skin, which makes it the perfect texture to have a similar appearance to animal leather.

Interestingly, the idea of using this raw material was mooted because this plant does not need any water to grow, and there is plenty of it throughout Mexico country. Before starting bulk production in various industries, it is essential to see the supply of cactus plant, the main raw material which should be stable and abundant. Presently they have 2 hectares where they cultivate cactus, as well as there is an expansion capacity of 40 hectares. Regarding production capacity, they can 500,000 linear meters of vegan leather a month.

The harvesting process includes the cactus cycle where they select and cut only the mature leaves of the plant around every 6 - 8 months. No irrigation systems are used as the cactus grow healthy with rainwater and earth minerals found in the soil. The vegan leather is made with leaves from the Prickly Pear Cactus. The mature leaves are cut from organically grown cactus plants, cleaned, mashed, and then left out in the sun to dry for three days until the desired humidity levels are achieved, before processing. The process for cactus leather involves using either the new young leaves or the mature leaves of the plant. It can then be dyed naturally using methods developed by the three innovators Adriano Di Marti, López Velarde’s, and Cázarez’s. This makes for vegan leather that is certified organic and can hold up to regular usage for nearly a decade. The organic raw material is then processed and mixed with non-toxic chemicals and then shaped into any texture and color. The ranch is fully organic, so no herbicides or pesticides are used in the process. All the remaining organic cactus material which are not used is exported and sold nationally to the food industry.

Properties of Vegan Leather

It is also flexible, breathable, durable, and does not stain making it an ideal replacement for animal and synthetic leather. The touch and feel of the material are also soft and very similar to real leather. The product is also highly sustainable with a lower carbon footprint than other leather alternatives. The finest point is 1. It is less water-intensive 2. It is Free from phthalates The “ Desserto “ cactus vegan leather has been manufactured as per the technical specifications required by the fashion, leather goods, furniture, and even automotive industries. It is having a durability of around ten years, the cactus leather’s basic features, elasticity, customizable and breathable, are like those of animal or synthetic leather.

Uses of Plant Leather

Apart from being natural and crueltyfree, the material also meets the specifications of several industries and can be used in: 1. Fashion

2. Leather goods 3. Automobiles

4. Furniture

Vegan leather is on par, in terms of pricing, with genuine leather. So far, the company has created car seats, shoes, handbags, and even apparel. In another plus for the environment, cactus leather is partially biodegradable and does not contain any plastic—another issue with synthetic leather. This makes for a true alternative to animal leather that does not harm the planet.

FACTS

Ages of Siberians and Scandinavians have been utilizing Salmon leather for quite a long time. Having started in Siberia, the antiquated craft of assembling Salmon leather has consistently been near and is more eco-accommodating in light of the utilization of the vegetable tanning strategy. Anyway, Salmon leather never acquired notoriety because of the lessening quantities of wild Salmon in specific spaces of the world and the wide accessibility of creature skin.

STUDY OF LEATHER FABRIC

PRADNYA AVHAD

DKTE Society’s Textile and Engineering Institute, Icchalkaranji

Abstract

Leather is a durable and flexible material created by tanning the animal raw hide. The mainly used raw material is cattle hide and skin. Leather usage has come under criticism in the 20th and 21st centuries by Animal Rights groups. These groups claim that buying or wearing leather is unethical because producing leather requires animals to be killed. However, according to the LCA report for the United Nations Industrial Development Organization, most of the raw hides and skins used in the production of leather were derived from animals that are raised for meat and/or dairy production. The skin and hide from the meat industry may create a major pollution. It can be either burnt or buried in landfill. Leather production utilizes the nonusable part of dead animals, so that, there will no waste of animals’ skin. It helps to decrease dead animal waste and improves economic growth of India by maximizing export of leather goods.

Introduction

Leather is processed by tanning animal raw hide and skins to make it durable and flexible. It can be produced at manufacturing scales ranging from artisan to modern industrial scale. Leather making has been practiced for more than 7,000 years; the earliest record of leather artifacts dates to 2200 BCE. Leather is used to make a variety of articles. It is produced in a wide variety of types and styles and decorated by a wide range of techniques as in Fig. No.1.

Leather usage has come under criticism in the 20th and 21st centuries by animal rights groups. These groups claim that buying or wearing leather is unethical because producing leather requires animals to be killed. However, according to the LCA report for the United Nations Industrial Development Organization, 99% of the raw hides and skins used in the production of leather derive from animals raised for meat and/or dairy production.

Manufacturing Process

The leather manufacturing process is divided into three fundamental subprocesses: 1. Preparatory stages, 2. Tanning, and 3. Crusting. A further sub-process of finishing can be added into the leather processing sequence, but not all leathers receive finishing. 1. The preparatory stages are when the hide is prepared for tanning. Preparatory stages may include soaking, hair removal, liming, deliming, bating, bleaching, and pickling. 2. Tanning is a process that stabilizes the proteins, particularly collagen, of the raw hide to increase the thermal, chemical, and microbiological stability of the hides and skins. Thus, making it suitable for a wide variety of end applications. The principal difference between raw and tanned hides is that raw hides dry out to form a hard, inflexible material that, when rewetted, will putrefy, while tanned material dries to a flexible form that does not become putrid when rewetted. Many tanning methods and materials exist. The typical process sees tanners load the hides into a drum and immerse them in a tank that contains the tanning "liquor." The hides soak while the drum slowly rotates about its axis, and the tanning liquor slowly penetrates through the full thickness of the hide. Once the process achieves even penetration, workers slowly raise the liquor’s pH in a process called basification, which fixes the tanning material to the leather. The more tanning material fixed, the higher the leather’s hydrothermal stability and shrinkage temperature resistance. 3. Crusting is a process that thins and lubricates leather. It often includes a coloring operation. Chemicals added during crusting must be fixed in place. Crusting culminates with a drying and softening operation, and may include splitting, shaving, dyeing, whitening or other methods.

Finishing Process for some leathers, tanners apply a surface coating, called finishing. Finishing operations can include oiling, brushing, buffing, coating, polishing, embossing, glazing, or tumbling, among others. Leather can be oiled to improve its water resistance. This currying process after tanning supplements the natural oils remaining in the leather itself, which can be washed out through repeated exposure to water. Frequent oiling of leather, with mink oil, neat’s-foot oil, or a similar material keeps it supple and improves its lifespan dramati-

cally [1].

Tanning methods

Tanning processes largely differ in which chemicals are used in the tanning liquor. Some common types include:

Vegetable-tanned leather is tanned using tannins extracted from vegetable matter, such as tree bark prepared in bark mills. It is the oldest known method.

Chrome-tanned leather is tanned using chromium sulfate and other chromium salts. It is also known as "wet blue" for the pale blue color of the undyed leather Aldehyde-tanned leather is tanned using glutaraldehyde or oxazolidine compounds. It is referred to as "wet white" due to its pale cream color. Chamois leather is a form of aldehyde tanning that produces a porous and highly water-absorbent leather. Chamois leather is made using marine oils. Brain tanned leathers are made by a labor-intensive process that uses emulsified oils, often those of animal brains such as deer, cattle, and buffalo. Alum leather is transformed using aluminum salts mixed with a variety of binders and protein sources, such as flour and egg yolk. Alum leather is not actually tanned; rather the process is called tawing.

Grades of Leather

 Top grain leather  Full grain leather  Corrected grain leather  Split leather  Bicast leather

 Patent leather

 Suede leather

 Bonded leather

Properties of Leather

 Leather has High tensile strength i.e., cow leather is between 8 – 25 N / mm². Leather with higher fat content has a higher tear strength. But there are many other parameters that influence the tear strength, the tanning method, the finish, the stiffness, or the age of the leather. Since leather is a natural product, every skin behaves differently. Resistance to tear is an important property. Good leather is stable and resistant to tearing, whereas suede, nubuck or extremely soft lambskin will not have the same stability as, for example, a belted leather.

 High resistance to flexing i.e., the ability to withstand numerous flexing cycles without damage or deterioration. Better mouldability, it can be molded into a certain shape and then remolded into another shape later.

 Permeability to water vapor i.e., enables leather to absorb water and perspiration.

 Good thermostatic properties i.e. The leather is warm in winter and cool in summer. It is resistant to heat and fire. Leather provides good heat insulation.

 The leather is resistant to abrasion in both wet and dry environments. This makes leather an excellent protector of skin.

 Resistant to Fire, fungi, and chemical attack.

Advantages of Leather

Leather is truly sustainable and natural fiber. Good leather ages well and can keep for long period. Leather is easy to repair and easy to maintenance. Leather products can be recycled and have natural comfort. Leather is more luxurious and have beautiful surface area. It has many ends uses as follows- Leather can be used as binder for finished books. It is often used to make clothing including pants, skirt, raincoats, and jackets. Leather has been used for all types of equestrian related products, including horse hoof boots. also, From fashionable winter gloves to durable work gloves. Fashionable footwear is one of the most common uses for leather, including boots, shoes, slippers, and more. Couches, chairs, recliners, and even automotive interiors are made from leather. Leather can be used for accessories like wristwatch straps, jewellery, belts, wallets, bags, and purses etc.

Disadvantages

Leather is more sensitive to fluctuations in temperature, where it can feel warmer in summer and cold in winter. When it comes to color and patterns, combinations of color and patterns are limited. It has main drawback i.e., producing leather requires animals to be killed.

Conclusion

This study gives us basic information of leather i.e., history, manufacturing process, applications, etc. Which shows leather is a natural, biodegradable fabric. It is made from tanning of animal skin. The rawhide and skin used for leather manufacturing is comes from, 99% of the raw hides and skins used in the production of leather derive from animals raised for meat and/or dairy production. Leather productions utilize non usable part of dead animals, so that there will no waste of animals.

References

1. "Interesting Facts about Leather"

https://www.decorium.com/tag/disadvantages-of-leather/ CalTrend. Retrieved 7 February 2018.

2. Applications

https://en.wikipedia.org/wiki/ Leather#Production_processes

3. Properties

https://saddlesindia.com/properties-ofleather/

https://www.colourlock.com/blog/AdvantageLeather/

4. Basic Information- Manufacturing process. https://en.wikipedia.org/wiki/Leather