In Conversation with Angela: An Inside View into Tuscany's Famous Leather Factories

Could you tell me a bit about yourself? 

 

Sure. My name is Angelo, I'm based in Tuscany of Italy, and I'm actually a Chemist. I’ve studied at Pisa University, and my job is to make sure to cover all the aspects of the leather making. From making sure that the chemicals are compliant with the international regulations, to the analysis of the actual finished leather, and the compliance with the various brands RSL (restricted substances list).

 

Do you see bioplastics as a sustainable alternative to plastic in the future? How about alternative leathers, such as mushroom leather as an alternative to leather in the future? What do you think are the possibilities?

 

The leather process consists of several steps from hide to finished leather; we can distinguish two main areas of the process: wet-phase and finishing phase. Traditionally the wet phase is conducted in large drums, and it’s aimed to unhair and tan the hide in order to preserve it, as well as clean it from the residues of the slaughterhouse. There are many different ways to carry out the tanning process but the two main technique are chromium tanning and vegetable tanning; in any case a considerable amount of water is involved. After the tanning process the leather is stable for many months, even years if stored in the right condition and it can be compared to a white canvas. This first part of the process is common for all sort of leather but from now on different recipes are used in order to achieve specific mechanical and commercial properties (strength, softness, grain size, colour, …) this step is part of the wet-phase and it’s called 're-tanning'. 

In modern leather-making, the re-tanning step involves many different chemicals, such as syntans (synthetic tannins), metal salts (chromium sulphate, zirconium sulphate, aluminium formicate… ), fat liquors (both natural and synthetic used as lubricant between the different fibril), silicones,  dyes, pigments and a great variety of polymers and many others. 

After drying, the leather is called crust and it can be stored for years and it’s ready for the finishing process. The finishing process involves mainly mechanical and chemical operation such as coating, spraying…

 

What is your definition of ‘sustainable’? / How is leather created from start to finish?

 

I wanted to answer both these questions in one. Let’s start with the word Sustainable which in my opinion is often abused and misunderstood. Sustainable it can’t be attached to any product regardless the whole process involved in its production. Manufacture of every part needed, every single Watt of energy, every waste and the all process involved in repurposing or disposing it and ultimately and most important even its utility it must be considered to define something as Sustainable.

My definition of sustainable it can be reassumed as: with a positive net yield for the whole planet in long time span.

That being said everything changes its prospective and there are no easy choices; things are not inherently good or bad, that’s why bioplastics can be the future of plastics for some specific applications where the 'yield' is favourable.

Alternative leather such as mushroom leather or plant base leather it can be a good but let’s not forger that hides are a waste and we have a thousand of years of experience to make leather in a sustainable way.

 

What are the most and least sustainable leather making practices? 

 

I think the most controversial aspect is that there are no standard values for how much chemicals can be used and how much wastes it can be generated per sq'ft of leather. Plus, very rarely materials are high performance due to studies and trials- most of the time new ingredients are added on old recipes regardless of the real improving mechanism. Optimisation, it’s often a forgotten key aspect of Sustainable thinking.