How leather is made? From rawhide to luxurious leather material.
Leather has been a part of human life for thousands of years, making its way from a basic necessity to a luxury symbol and fashion statement. From the earliest days of hunting and laborious hand tanning to the advanced and automated tanneries, leather has come a long way.
As we all know leather is a natural material that is obtained from tanning raw skins of animals. Leather can be made out of the skin of almost any animal. The leather tanning process is used to preserve the skin and prevent decomposition. The most common types of leather include cow leather, sheep leather, etc.
Leather has some unique properties that any other material cannot match and that makes it the perfect material for shoes and clothing. However, leather can also be used to make handbags, furniture, sports equipment, etc.
In this article, we will discuss different types of leather and How leather is made. In tanneries across the world. Furthermore, we will also discuss the various types of this amazing natural material called leather and much more. After reading this article you will have a thorough knowledge of leather making and its types.
Leather production method
Leather production is a multi-step process that includes a good amount of labor and expertise. Transforming raw skin into a durable material called leather is very interesting. Here’s an overview of leather making process.
1.| Preparation of hide
This process generally takes place at slaughterhouses where animals are slaughtered for their meat. The process begins with the trimming of extra flesh and fat. Then soak the skins in a salt solution. Salt prevents the skin from rotting and it can stay like this for up to 30 days. Other methods can also be used like freeing and using biocides but salt is commonly used.
2.| Soaking
After the salted raw skins have arrived at a tannery in the refrigerated truck they are soaked in water in order to remove the salt, dirt, or remaining blood. Water will also help hydrate the skin and make it softer, easy to work with. The salt is removed by tumbling and hammering the hides or a pit of water can also be employed to soak the hides.
3.| Liming
In this stage, the hides are soaked in lime solution to facilitate the removal of hair and outer skin called epidermis. It is done by using drum and peddle equipment or a pit can also be employed. Lime helps loosen the hair follicles by swelling of skin.
4.| Fleshing and deliming
This is the step just before the tanning process. In this step excess flesh is removed by manual cutting and the PH of the hide is balanced for tanning which is called deliming.
5.| Tanning
Tanning is the crucial stage in turning raw skin into leather. There are several methods of tanning such as chrome tanning, vegetable tanning, oil tanning, brain tanning, etc. Out of them chrome tanning a widely used in leather manufacturing. The process of chrome tanning begins by roaming the hide with a chemical bath containing chromium sulfate salts for like 8 hours so that chrome can penetrate into the skin properly. Then sodium carbonate is added to fix the chrome salts and it is the final treatment after which the can be technically called leather.
Another method used for tanning is vegetable tanning in which a natural tanning substance is used that is extracted from tree bark. This method of tanning is comparatively slow and vegetable leather obtained by this method of tanning is more expensive.
6.| Splitting
After tanning follow the process called splitting in which the desired thickness of hide is obtained by splitting the hide using a machine called a leather splitting machine. By carefully controlling the splitting process, manufacturers can tailor the properties of the leather to meet specific requirements for different applications.
7.| Dyeing and fat liquoring
Once tanned the leather is ready for dyeing to get the desired color and softness. Hydes are put into drums of dye, they are inspected to ensure the full saturation of hides by color dye. Dyeing is followed by a process called fat liquoring in which various oils and emulsifiers are induced in leather to make it softer and moisture resistant.
8.| Drying
After the leather is dyed and oils are added it undergoes a drying process. This process can employ natural air drying or vacuum drying techniques. Proper drying ensures that the leather retains its properties and stays flexible.
9.| Finishing
After drying leather undergoes the surface finishing process in which the desired surface is obtained by various processes like sanding, buffing, embossing, polishing, or applying surface coatings to get the preferred texture.
10.| Inspection
The final step is a quality check in which various tests are done on leather to ensure that the finished leather meets industry standards for strength, durability, colorfastness, and overall quality. Also, the hides that pass the quality test are stamped with the dimensions in square feet or square yards depending on the market.
Types of leather
The leather obtained by the above manufacturing process can be classified into three major leather categories Top grain, split, and bonded leather.
Top grain leather
Top grain, is the leather made from the outer layer of the hide, where the fibers are tightly packed and relatively uniform in appearance. Top grain leather is a high-quality kind of leather known for its durability.
Types of top grain leather:
Full grain: contains the entire grain layer, without any removal of the surface. It is considered the highest grade of leather and it is the most durable of all types of leather.
Corrected grain: Corrected grain leather is often called top grain leather. Its surface is subjected to treatments such as sand, buffing, or embossing to get a uniform surface finish.
Nubuck: Nu buck is a type of leather that has a velvety surface finish. It is obtained by sanding and buffing the top grain leather.
Split Leather
During the leather-making process, the hide is split into multiple layers, with the top grain layer used for premium leather such as top grain, and the remaining layers, known as drop splits, used for split leather. In thicker hides drop split can further be split into middle and flesh split.
Types of split leather
Suede: Split leather has a napped finish and fibrous texture on both sides, as it lacks the smooth surface characteristic of top grain leather.
Bicast: It is a split leather that is considered less durable, coated with PVC or polyurethane, and embossed to mimic the grain texture.
Patent leather: It is a split leather that has been given a high gloss surface by additional coating.
Bonded leather
Bonded leather is the cheapest and least durable kind of leather. It is made of leather scraps that are shredded and bonded by a latex binder. The amount of leather fibers in the mix can be as low as only 10%, the majority of its composition consists of synthetic materials.
Environmental impact of leather making
The main product of an animal is meat and hide is just a bi-product, which would otherwise have gone to waste.
But chemicals used to process that are toxic in nature such as chrome salts are considered as huge sources of pollution. However, leather products last much longer than their synthetic counterparts and need not be replaced often simply because it is worn out. And when it does wear out, it’ll biodegrade.
Some of the effects can be reduced by responsible activities, for which there are various government schemes and guidelines which are highly regulated.
Conclusion
I hope you enjoyed our in-depth article and got the answer to the question: How leather is made?
For more information on leather products, you can check our other articles or you can contact us. LeatherBlues is known as one of the best stores for real leather products. Explore our amazing collection of leather garments and services.
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