The first important fact to understand about making upholstery leather from Bovine/cattle is that the hide is a by-product of the meat and dairy industry. No animal is raised for their hide. If not for the leather industry, all hides would be disposed in a landfill. This makes the first step in the leather making process hide preparation. Leather making has many steps which can be grouped into four main processes:
1. Preparation
The preparation process prepares the hide for tanning and consists of curing, soaking, liming, fleshing, splitting, deliming, bating and pickling. The first step, curing, takes place prior to the tannery to ensure the hides do not spoil prior to arrival at the tannery. The highest quality pure aniline leathers are made from fresh hides which are not cured–requiring quick transport from the raw hide supplier to the tannery.
The remaining steps of preparation occur in large wooden drums in the section of the tannery known as the beamhouse. In the beamhouse, the hides are cleaned and unwanted materials such as hair and flesh are removed so that only the fibrous collagen structure that gives leather its strength and flexibility remain.
Also during preparation the hide is split to separate it into the top-grain layer and the flesh split. The top-grain layer contains the fibrous collagen section and so is used for most high-quality upholstery leathers requiring strength, durability and softness. The flesh split is typically used to make suede leather, lower-quality split leather or dog bones.
2. Tanning
The Tanning process converts the perishable hide to leather which is non-perishable, strong, flexible and stable under varying conditions of heat and moisture. Tanning steps include tanning, samming and shaving. Tanning occurs in large drums which slowly rotate so that the tanning agents (commonly known as “liquors”) are slowly worked into the full thickness of the hide. There are three common types of tanning, all of which are used for different leather lines by Cortina Leathers:
– CHROME TANNAGE
– CHROME-FREE TANNAGE
– VEGETABLE TANKAGE
3. Retanning
In the retanning process, the leather is given its required specific properties for each leather line or product, as defined by the finishing house or customer. Softness, fullness, density, elongation, the break of the leather, the leather color, etc. are all adjusted or imparted in the retanning process. Steps in the retanning process include neutralization, aniline dying, retanning, softening, drying and buffing the leather.
All the steps prior to drying occur in drums ranging in size from 10 to 300 hides. Most high quality leathers, including all Cortina Leathers, are aniline dyed in the drum. In this process, a rich color is achieved by introducing aniline dyes to the drum mix which is slowly turned until the color penetrate throughout the thickness of the hide. A range of drying methods including vacuum drying, toggling, or suspension drying.
At the conclusion of the retanning process, the leather is known as crust. At this point it is typically transported to a leather finisher.
4. Finishing
The process of Leather finishing creates the final desired characteristics of the leather such as look, color, protection, grain and hand. Steps include milling, staking, oiling, waxing, rolling, spraying, topcoat application, embossing, hand-rubbing, finiflex, ironing, and more. However, not all steps are applied to each leather.
By varying the finishing steps, settings at each step and the formulations of each treatment, leather finishers can create all leather types (pure aniline, aniline, semi-aniline or pigmented) in with crust prepared with the same preparation, tanning and retanning process. Within a category many different looks can be created.
Thank you for visiting our website! We hope you will find something of interest on our website. Watch the video in the below
