The tanning process
The process called "tanning" has as its objective the transformation of a perishable product, raw leather, into a durable, resistant material that is pleasant to the touch and sight, which at the same time retains all the properties of the leather.
The art of tanning, one of the oldest that man has developed, is still strongly anchored to tradition. However, thanks to technological development, it has been possible to reach previously unthinkable levels of creativity and personalization.
Since 90% of the tanning process is controlled internally at Conceria Tris, our customers can attend all phases in total transparency and with the complete availability of the staff.
In this page we guide you inside Conceria Tris, illustrating all the steps of tanning, from raw to finished leather .
01
Desalting
The raw hides that arrive in the tannery are covered with salt, a substance that delays its deterioration. The first step is therefore that of desalting. A rotating and perforated cylinder allows, by mechanical shaking, the removal of the salt. The latter is recovered for other uses, while the desalted hides continue on to the next step.
02
Greening and hair removal
Soaking takes place inside special drums, i.e. the rehydration of the skins and the removal of impurities. Within the same drums, hair removal also takes place, that is the removal of the hair thanks to the combination of mechanical shaking, sulphides and sulphhydrates. At the end of this process we will obtain what are called "pelli in trippa".
.jpeg)
03
Fleshing and trimming
The hides are passed through a rotating cylinder for fleshing, i.e. the elimination of excess subcutaneous fat residues. Subsequently, the trimmers eliminate the unusable parts, giving the hides a more regular shape.
04
Split
This delicate phase allows to separate the upper part of the leather, called "grain", from the one below, called "split". A special machine allows you to make this cut very precisely.
05
Tanning
The leather is now ready for perhaps the most important phase: tanning. Inside dedicated drums, the skins are purified from lime residues and brought back through the pickel to levels of acidity that allow the tanning substances to penetrate. Finally, the real tanning takes place, that is the addition of substances that allow to block the natural perishable nature of the leather to make it a long-lasting product. At the end of this tanning process we will obtain the "wet blue".
06
Pressing
The wet blue leathers are still very wet, therefore they are pressed by special machines that allow to eliminate excess water and creases.
08
Retanning
The hides return to other drums, dedicated to retanning. It is in this phase that the hides are dyed in all their thickness. Furthermore, retanning is essential to give the leather the desired consistency. Also in this phase, the leathers are greased to obtain greater softness.
07
Shaving
With shaving we want to equalize the thickness of the leathers to make them as homogeneous as possible and therefore more easily usable.
09
Drying and staking
Before being able to give the final look to the grain of the leather, it must be completely dried. Drying can take place in three ways: vacuum, air or on a frame. The choice of the type of drying is important for the type of desired result.
After being dried, the hides are passed through the staking machine, a machine which, thanks to the rapid movement, restores softness.
The dried and staked leathers are called "crust leathers".
10
Grinding
In some cases it is necessary to correct the grain to reduce the natural defects of the leather. A special machine removes a very thin layer of the grain by abrasion.
This phase is skipped in case you want to obtain full grain leathers.
12
Fulling
In the fulling barrels, the effect of natural grain is restored to the leathers through humidity and movement. This phase is avoided if the desired effect is the smooth one.
11
Finishing
The hides are fed into a machine called spraying machine, a tunnel inside which various computerized rotating sprays apply resins and dyes to give the leather a homogeneous color. Other substances capable of conferring particular touches and effects can also be applied.
13
Ironing
Thanks to the heat and pressure, the previously sprayed resins are reactivated to obtain a more or less glossy effect.
14
Selection and measurement
The employees select the finished leathers based on the presence or absence of natural leather defects.
Finally, the hides are measured to the centimeter through a machine called measurer. The measurement is shown on each skin on the side opposite the grain, called the flesh side. The skin then goes to the laboratory for the necessary checks.
