The breakthrough of waterproof leatherThe Dutch company presents an innovative technology based on silicon polymers that could be the new benchmark for water-repellent treatments. Lionel Champanhet, senior technical manager of Stahl, explains to us differences and advantages
Stahl is preparing to launch on the market a new technology to waterproof leather destined to revolutionise the water-repellent treatments. First of all because the solution developed by a team of experts ensures high sustainability. “Thanks to a new generation of silicone agents (PFC- and BTX free) we have developed a high-performance waterproofing leather process with low environmental impact”, explains the official note of the Dutch company. One of the world’s leading experts in water repellent leather helps us to better understand the scope of the novelty: Lionel Champanhet, today a senior technical manager at Stahl and, before the acquisition of his Leather Division, at BASF. “This new technology is really important because it offers tanners a clean, fast and effective process to make high quality waterproof leathers. I am convinced that this system will become the new market benchmark, valid for the next 20 years”, explains the expert.
Can you explain how it works in general?
“The system is based on two new generation polymeric agents of the Densodrin® and Densotan® family that are totally free of solvents and benzene and fully meet the MRSL parameters of ZDHC. These products are fixed on the fibre of the leather with an exhaustion of 99% and, unlike the oil or paraffin-based treatments used so far, they also require a lower quantity of water and lower temperatures with obvious advantages both on the carbon footprint and on the water footprint of the tannery that uses them. The process also requires less energy because it is shorter than traditional systems, and the machinery used requires less maintenance”.
Are there any advantages even on finished leathers?
“Leathers waterproofed with this system have a higher yield, last longer and show better technical and physical resistance, and also a better vapour permeability”.
How long did it take to develop this technology?
“For over thirty years we have been studying the best technology to make leather water repellent first at BASF, then at Stahl. In our opinion, this new system represents an epoch-making change because it overcomes the paraffin-based treatment to move on to a completely polymeric process that offers great technical and environmental advantages. In 2007, BASF launched the first of this family of silicone polymers, which is still working well, but which has application limits. Now, with the addition of these two new products, at Stahl we have a range that allows us to produce any type of leather for clothings, gloves, bags and shoes. We are also studying applications for the furniture industry”.
What is the difference with the water-repellent product range that Stahl already proposed?
“From a chemical point of view the products are different, but the application is similar and does not require a change of machinery and technology by tanneries. The waterproofing agents used in this new technology are more versatile and can be added to different stages of the tanning process, while the water-repellent products in the leather finishing range are used at a specific point in the process to be effective. Moreover, with this system you can build and modulate the waterproof effect, layer by layer, above and below the leather, obtaining a personalised result”.
When will the official launch take place?
“The new technology will be launched at the APLF in Hong Kong next March 13, where at the Stahl booth (hall 1A, B02) we will also show a series of waterproof leathers produced in very different situations in countries like India, Singapore, Thailand, China but also Holland, to make people understand that the result is always the same regardless of the geographical location in which it is made, because it is a very stable process”.