CURTIEMBRE UNAC-FIQ

Summary

This script offers an in-depth look into the leather production process, detailing the sourcing from various animal hides and the meticulous steps involved. It covers the curing of raw hides, the crucial dehairing and fleshing stages, and the different types of tanning methods such as vegetable, chrome, and mineral. The script also highlights the importance of processes like splitting, dyeing, and finishing, which contribute to the leather's durability, flexibility, and resistance to decay. The quality control measures ensure the leather meets industry standards for thickness, softness, and finish, before the final inspection and cutting for use in a wide range of products.

Takeaways

• 🐂 Leather is made from the skin of animals, prepared chemically to create a robust, flexible, and decay-resistant material.
• 🌍 The majority of the world's leather production comes from cattle, goat, and sheep skins, with lesser amounts from horse, pig, kangaroo, deer, seal, and various reptiles.
• 🔪 The leather production process starts with cured, fleshed, and hair-free raw hides.
• 🧼 Raw hides are initially cured using salt or other methods, and the fleshing process is crucial for market-oriented product shaping.
• 🔉 The splitting process involves passing the leather through a machine called a 'divider' to achieve a uniform thickness.
• 🛁 In the tanning process, hides are soaked in lime water to remove dirt and blood, and may undergo re-tanning for whiteness enhancement.
• 💦 The wet-blue tanning process involves soaking in calcium hydroxide, and the leather then goes through a process to remove excess water.
• 🔄 The leather is then thinned to a uniform thickness, typically between 2 and 10 mm, before drying.
• 🌞 Drying methods include using drying chambers, ovens, tunnel drying, or open-air drying, with the latter being the most recommended.
• 🛠️ After drying, the leather undergoes flatting and curing processes to impregnate it with a mixture of chemicals to improve water resistance and other properties.
• 🔧 The vacuum drying process uses a hydraulic ring pump to reduce pressure and evaporate water from the leather.
• 🎨 The finishing process involves applying a finishing product to the leather surface and brushing it with a bristle cylinder to correct imperfections.
• 🔍 Quality control in the lab includes measuring leather thickness and ensuring compliance with quality standards before the final finishing.
• ✂️ Finished leather undergoes rigorous inspection and cutting, with checks for softness, touch, fullness, gloss, grain, firmness, and color.

Q & A

What is leather and what materials is it primarily made from?

Leather is the skin of an animal that has been chemically prepared to create a robust, flexible, and decay-resistant material. Most of the global leather production comes from cow, goat, and sheep hides, although less commonly, it is also made from horse, pig, kangaroo, deer, seal, and various reptile skins.

What is the initial process for leather production after the animal is skinned?

The initial process for leather production involves curing the raw hides, which can be done by salting or drying, depending on the thickness and type of hide.

What is the purpose of the 'selvedge' or 'skiving' process in leather production?

The selvedge or skiving process involves passing the leather through a machine called a 'divider' to separate it into two parts. This is done to achieve a uniform thickness for the leather, depending on the desired finish.

What is the 'pickling' process in leather production and what is its purpose?

Pickling is the process where leather is soaked in a lime water solution at a temperature between 10 and 15 degrees Celsius. The purpose is to remove any remaining dirt and blood from the leather.

What are the different types of wet curing processes mentioned in the script?

The script mentions several types of wet curing processes, including wet white curing, wet chromium curing, and wet mineral curing.

What is the purpose of the 'exudation' process in leather production?

The exudation process involves removing the maximum amount of water from the wet-cured leather, adjusting its thickness to a range between 2 and 10 mm for further processing.

What are the various methods of drying leather mentioned in the script?

The script mentions several methods of drying leather, including drying in drying chambers, tunnel ovens, open-air drying, and pasting, with open-air drying being the most recommended.

What is the 're-tanning' process and its purpose in leather production?

Re-tanning is a process where the dry leather is impregnated with a hot mixture of chemical products to increase its water resistance, improve its properties, and ensure uniformity in the tanning process.

What is the 'vacuum drying' process and how does it work?

Vacuum drying is a process that takes place on a flat stainless steel platform with holes, covered by a hinged lid. It involves a water ring pump to reduce pressure, and the lower plate acts as a heater to evaporate the water from the leather.

What is the finishing process in leather production and why is it important?

The finishing process involves applying a finishing product to the leather surface and brushing it with a bristle cylinder. This is important to correct imperfections in fine leathers and to achieve the desired look and feel.

What is the role of quality control in the leather production process?

Quality control in leather production involves measuring the thickness of the leather to meet quality standards and ensuring that the finished leather meets various characteristics such as softness, touch, fullness, gloss, grain, firmness, and color.