An idea is born. In 2004 Yemm & Hart sought a 100% post-consumer cork floor tile for a construction project. None could be found. How could this be with all of the vineyards throughout the United States and knowledge that moderate wine consumption is beneficial to health? Why weren't the corks from all of this consumed wine getting recycled and converted into something useful? Metal, glass, plastic, paper, cardboard, carpet, electronics, and batteries are all getting recycled. The trouble with recycling wine corks is that, in spite of the great quantities, wine corks are small and not every family or business generates them. Thus, they tend to get overlooked by municipal recycling programs due to low volume.
Wine cork recycling begins. As with our Origins product, we started out to create a 100% Post-Consumer cork material that acknowledged its origins. We thought it would be great if the whole corks, the used wine stoppers, were visible in the product. Yemm & Hart put the word out through their website and before long, people and businesses began sending us their corks to recycle.
Sufficient cork volume is reached to begin manufacturing trials. There was a geometric challenge to solve. A whole wine cork stopper is a 3-dimensional object and when placed close together, there is a considerable size void that needs to be filled. We felt that filling this void with a synthetic material would not be appreciated by most people that enjoy cork floor and wall covering. We tried filling the void with the abundant supplies of SBR tire buffings. Although this really helped the product acknowledge its origins, we didn't think it would appeal to people for the same reasons as using a synthetic filler. We believed that those people that seek cork for their interior environments want cork and not rubber. Both of these fillers types would make the tiles virtually impossible to recycle.
Granulated cork was next tried to fill the voids and we thought that it showed the best results so far. We sent out samples of this test and they were well received. Our second batch of this formula had some serious defects. In the manufacturing of granulated cork or rubber products, a polyurethane binder is used to join all of the various size pieces together. The 2nd batch of this formula proved that the 18-35 cork granule size was just too small to reliably allow the liquid polyurethane to penetrate and encapsulate to cork particles.
Repeatability with a satisfying look was what we needed from our next test. This was what we call 60/40-10-20. This is, like the tests before it, 60% whole wine cork stoppers but with a larger, 10-20, cork granule size making up the 40%. This granule size allowed for the complete coverage of every granule with the polyurethane binder. The whole corks were not quite as distinct as when using a smaller cork granule but this was a formula that was repeatable without defects. The product development was almost complete but challenges remained, such as contamination, lack of high speed manufacturing and the question of whether or not this product can be made 100% post-consumer.
Contamination in post-consumer cork, as in the overall post-consumer waste stream, is a major factor when transforming waste into a useful commodity. Metal, glass and plastics are melted and the impurities are either burned off or screened out. Paper and cardboard are shredded and mixed with water to become pulp. This can't be done with whole corks if the corks are to remain whole in the finished product. There were 2 solutions that we found for removing contamination from whole corks. The low tech method was to utilize human skill to visually identify and remove any contamination. The high tech method was to use a specially configured machine to automatically identify and remove contamination from the corks. For either method, the cost of decontaminating post-consumer cork was significant.
Post-consumer granulated cork is possible to produce. However, to efficiently granulate cork, it takes sophisticated equipment. Granulating cork is not as simple as grinding coffee beans. For the efficient granulation of cork, each desired granule size must be carefully screened. For example, granulating one of the larger sizes, such as 1/2-4 still produces many smaller granules of cork that require screening. The next larger size is then granulated and the smaller particles generated are screened out. The process continues until only the finest 80/0 dust remains. This process requires a great many screens and the whole operation must be protected from fire at all times, since dust is flammable. As in any other form of recycling, cork granulation is a continuous process and tracking a batch of post-consumer wine cork stoppers among a significantly larger amount of post-industrial cork is nearly impossible.
A realistic price was our goal for the Wine Cork Tile product. If we were to insist on 100% post-consumer or nothing, the cost for the cork decontamination and the cost for tracking post-consumer corks through the granulation process would be so great that the final cost to the consumer would be unbearable. Since there is no point in that, we have had to make compromises in our initial idea. This is to utilize the high speed/high volume processes and equipment available to us that are the same methods used for processing the waste left over from the manufacturing of new wine cork stoppers such as the cork webbing pictured here. This material is post-industrial waste because the cork has not been used by the consumer yet.
The confluence of formula, repeatability and price is a lamination using common PVA wood working glue. The top 1.2 mm thick layer is the more expensive 50% whole corks and 50% 5-10 size cork granules and the bottom layer is a 3.6 mm thick substrate of 5-10 cork granules. The result is a 100% recycled and 100% cork floor and wall tile. This has become our standard pattern and it is identified on the Wine Cork Tile Price List. There are numerous options for Wine Cork Tiles shown on the price list.
Batch sizes can be significant. To make Wine Cork Tiles, whole corks are mixed with granulated cork and a food grade polyurethane binder. The mixture is heated and pressed into a block or cylinder which is then sliced into thin sheets. Sheets can be cut into tiles or laminated to a substrate. The result is a cork material that has visible profiles of whole wine cork stoppers. A cork product made in this way allows the material to acknowledge its origins. We at Yemm & Hart, know that those that like a natural interior environment will like the warmth of cork. We also like to believe that such a material might help raise awareness about cork, where it comes from, who harvests it and what animals and plants live around the cork oak tree.
All that post-consumer cork that we collect, what happens to it? We have used these corks for experiments, as described above, in the development of the Wine Cork Tile product. If there is a demand and budget for 100% post-consumer recycled cork floor and wall tile, we have the raw material in stock. We have provided the recycled corks to resellers of post-consumer corks. We have also supplied large scale craft operations. We maintain an inventory of post-consumer wine corks so that we can quickly supply anyone with a need or a new idea with a completely natural organic material.
Thank you for considering Wine Cork Tiles for your projects.