An innovative solution for waterproofing leather12 April 2007
According to the inventors, from Leverkusen (LANXESS) and Philadelphia (Rohm and Haas), the new Lubritan products are impressive and bring some of the advantages of acrylic technology to the wet end of leather processing. The products provide lightweight leather with a natural feel without dyeing problems, waterproof but firm enough for hiking boots and offering improved finish adhesion. Could this be some of the 'long sought after' solutions to the tanner's problems? Leather International asked leather specialist Chris Tysoe about their recent product launches to find out if the new products really are as revolutionary as LANXESS say. Q The waterproof sector is highly competitive. Why are LANXESS still investing here? A Well, although the waterproof business is competitive it is still a substantial and potentially lucrative business that continues to show signs of growth. But of course these are not the only reasons. LANXESS is known as a leader in the supply of synthetic tanning agents, meaning that we are one of the most experienced companies in this sector. So this is why we are applying our accumulated knowledge in the waterproof business too. Let me explain: If a business is highly competitive, that does not mean that you cannot be successful anymore there and should leave it aside. The opposite is correct: Quite often these business areas are just hungry for innovative solutions. 'Competitive' can also mean having simple, outdated solutions and we are ready with new ideas to help our partners in the leather industry to be more successful than before. And together with our cooperation with Atlas in fatliquors, Rohm and Haas in acrylics and silicones, and our new dyestuff initiatives we are able to offer 'complete packages' in retanning, including waterproofing chemicals. A No, not at all. Because we have done our homework. We have been preparing our latest product initiatives for a long time. And we did not work alone. We joined forces with our partner, the global leader in acrylic technology for leather, Rohm and Haas. On the other hand you are right as well of course. There are many incumbent players doing business at the moment. But I believe no single company has adequately resolved the long standing problems and shortcomings of the existing technologies in the waterproof sector. We have studied long - and hard - the needs and problems of our customers before developing and launching what we consider to be the optimum solution available to date. One reason for our success here might be that we define ourselves not just as a simple supplier but also as a partner for our customers. We always try to learn from them. And we do learn, because we are widely recognized as 'problem solvers' and innovators. Our customers are working closely with us enabling us to be innovative every day! This will help us in the business with waterproof technologies as well. Q Can you explain the key features of your new offering? A One of the very cores of our technology is the idea that you cannot solve complicated challenges with one simple tool any more. So our answer is a well balanced dual product system. Lubritan XB basically is a unique polymer based product recommended for use in all waterproof formulations, specially designed to reduce water absorption. If boosting dynamic test results is required, we are introducing simultaneously Lubritan XS, a special silicone polymer. The fact is that both products can be combined to get waterproof leather with tailor-made properties to the required quality level. Customers working with either the Bally flexometer or the Maeser can now simply adjust the ratios of these two products to get the desired values or even to exceed them in a cost efficient way. Q What is so special - you said 'unique' - about your polymer technology? AIt's based on a polyacrylic solution! As known from finishing applications where polyacrylic polymers are successfully applied and widely exploited for some years already, this technology offers many advantages. Now we were able to apply it to the wet end. We believe that the properties attained through the application of these polymers have not been achieved before: acrylic chemistry is the major contributor to the high performance of the system. And, importantly, made it possible to offer it for a reasonable price! I am not aware of any cost effective system being offered currently that surpasses the performance results attained with our acrylics. LANXESS and Rohm and Haas again are true pioneers here: currently you won't find these polymer solutions elsewhere on the market. Q How do these polymers work in waterproofing? Is the chemical difference to common systems related to a new working mechanism? A There is a fundamental difference! Lubritan products coat the fibres rather than blocking the inter-fibre and fibril spaces as certain other products do. This not only delivers high product stability, it also has another important advantage: leather treated with Lubritan allows water vapour to pass more easily, thus resulting in higher WVP values and better wearer comfort. For this reason we call processing with these Lubritan products 'Open Waterproofing', as opposed to traditional systems which in comparison are 'Closed'. This is especially important when the waterproof leather is combined with other materials based on membrane technology, for example Goretex. With 'open' waterproofed leather moisture is no longer built up in the article; that of course will increase wearer comfort to a new level! Q What does that mean for the leathers processed with your systems? A With the new solutions we were happy to give the tanners what they have been asking us for many years. Lubritan XB and XS give tight, full leather, with lightweight and low density - simply because the inter-fibre spaces are not filled but the fibres are coated in a smart way at a very microscopic level. As you know, this is a real advantage compared to traditional systems as heavy, dense leathers can't offer optimal wearer comfort. On the other hand we now have a solution for customers complaining that traditional products used to attain higher water resistance had to be added in such large amounts that the leather becomes too soft. This is not the case with Lubritan XB and XS. Coupled with our recommended firmer syntans like Tanigan F, for example, leathers with a very high waterproof-performance can be supplied without compromising firmness and good 'stand' - which is ideal for robust hiking boots, where softness is not desired. We also knew that dyeing was another major problem for tanneries; until now it has always been hard to get a level dyeing on waterproof leather. With Lubritan products this is a problem of yesterday. Furthermore, the grain and flesh colour after dyeing is the same now. The typical dark flesh side problem is solved. Last, but not least the surface feel is dry and more natural. Q Finishing waterproof leather has always been a challenge. Does the finisher have to suffer for the technical advantages gained in the wet end? A No, not at all. As Lubritan products are based on a polymer technology related to the one most finishers use today, the compatibility of our waterproof-reagents to state-of-the-art finishing solutions can be even better than before. Polyacrylic polymers have a relatively high affinity to leather and do not migrate. We also found that our polymers used in the wet end tend to bond well to acrylics used in finishing - certainly better than to traditional waterproofing solutions based on waxes, greases or synthetic resins etc. For me this certainly is a significant step forward and represents another competitive advantage. Q Are there any special application conditions or procedures necessary with your system? A No. Lubritan XB and XS both demonstrate good stability including to hard water. Finally, we spent a reasonable part of our research in the development of a very robust system, meaning that our solutions are designed to give highly reproducible results. Customers don't need to buy any special expensive auxiliaries to make them work. Just the application of permanently hydrophilic products should be avoided and salts should be carefully washed out, but this is good practice in the tanning industry already. If the tanner observes the usual 'do's' and 'don'ts' of waterproof manufacture, such as careful opening up in liming, thorough deliming and through neutralising, the application of these new products will help to obtain optimal results in a more economic way.