Courovale metalfree bioleather
One important item inside sustainability politics is about the tanning/retanning leather process free of metal, internationally called “metal-free”.
However, before we get into that, we have to understand what that is supposed to mean. It exists some confusion when it comes to the nomenclature about this kind of leather. “Chrome-free” leathers, “metal-free” leathers, “wet-white” and “bioleathers” are distinct things.
“Chrome-free” are the leathers that tanned without chrome, but not necessarily without metal. Those leathers are processed with some organic products, or other metals, such as Titanium or Zirconium. Therefore, not all “chrome-free” leathers are necessarily “metal-free” leathers too. The “wet-white” tanning process is every process that produces light colors, however, this doesn´t mean that it is free of metals.
The “bioleather”, a widely used term, is a “metal-free” tanning process, but with more other requirements about product restriction. In addition to the chrome exemption, there must be, also, a nonylphenol, azo dye, formaldehyde, and many more, exemptions.
The technology utilized in this new process, which was developed and incremented mainly due to the European and the US community resolution. This resolution was created to attend automobile car recycling problems. The legal restrictions are being used to the chromium levels; this level precludes the chrome use as a tanning agent.
The chrome metal is one of the most utilized in the leather industry, and its success has many reasons. The results that come from the chrome utilization are excellent, softer leathers are produced, and with high retraction temperature. This process is also widely known for its easiness and utilization.
The existent requirements from transforming industries, such as footwear and automotive, lead to the development of processing technologies that don´t pollute the environment and minimize the atmospheric emissions, waste generation, and the organic load that is present on the effluents. The use of this new type of leather promotes a big differential on your products. Chrome tanned leathers used on car upholstery when incinerated; transform the Chrome +3 into Chrome +6, and this new substance is highly toxic, mostly because of its oxidant behavior.
In Brazil, there is already strong legislation that actively controls effluents, sharing machine sawdust and wet blue trimmings. There isn´t happening a car upholstery recycling process likely to the European standards in the country right now, but we will get there one day.
Certainly, there is not a technological level that provides a total chrome substitution for other non-metal elements, and there isn´t a necessity as well. When it comes to car upholstery or any other product made with chrome-tanned leather, or chrome retanned leather, and that is going to be burned or recycled, it should respect this new technology.
For now, we can name many technical advantages in the use of this technology, such as:
1. The Leather it’s easy to sammying.
2. It’s easy to paring out.
3. There is no great variation in the thickness of the leather after paring.
4. Leather shrinkage temperature around 82°C (er need to improve to reach 100°C).
5. Leather is free of all types of heavy metals.
6. Flexibility when referring to the process after the tanning, like dyeing, fatliquor, being possible to use different types of tanning products.
7. Differentiated process.
8. Light coloring (almost white), which makes white leather and pastel tones leather production easier.
9. Provides dyeing of more bright and uniform tones.