The vulcanized outsole of the shoe is a durable and ecological choice. Vulcanizing the outsole of the shoe generates very little waste – only a few percent, and no traditional adhesives are needed to attach the sole of the shoe at all. The sole is only 3 mm thick and is very flexible.
The direct vulcanization of the outsole used by Feelmax’s differs from the gluing method used by other shoe manufacturers in that the rubber mixture is melted without adhesives in a hot mold directly onto the upper part of the shoe. Normally, the outsole is made separately in a mold and the overgrown “swellings” are cut off before gluing. This makes the bottom cosmetically smooth. But harmful adhesives must be used to attach the outsole to the shoe.
Because we use recycled rubber in the outsoles of the shoe, the molding properties of the rubber in the mold vary – depending on the different batches of rubber – more than the normal rubber compound. This in turn can cause the rubber compound to burst out of the mold. Because in this process the outsole is already attached to the upper part of the shoe, it is difficult, sometimes even impossible, to remove these bursts. The melting technique is difficult to control right at the edges of the outsole, at the junction of the top part of the shoe and the outsole, and the end result is not always cosmetically “perfect”.
The outsole which is made of a recycled rubber may not be perfectly flat, but may show a variety of lines, small bumps, air bubbles, and other imperfections.
We strongly believe that the benefits of direct vulcanization are clearly better by minor cosmetic defects on the shoe. Our outsole of the shoe is arguably the most flexible outsole on the market. It has excellent wear resistance, and the outsole sticks on the shoe really strongly!