The STEMMA Patent for Triple Density Becomes “Global”

Stemma gives new impetus to the production of shoes with three-density soles as its technologies are now patented in the most important international markets.

Developed in Italy in the late 1980s, triple density injected polyurethane soles were used for a long time only for high-end trekking footwear. The reasons that had limited its wider diffusion can be traced back to the complexity of the production process and the resulting high production costs.

The change in trend and the renewed market interest in this type of soles began in 2018, when Stemma introduced the new “PLUS2” technology. This process for the production of three-density soles, using double polyurethane injection combined with pre-moulded rubber or TPU treads, has made it possible to produce three-density soles at a similar cost to that of traditional two-density, thus making them accessible to a much wider range of products.

The “PLUS2” is a ground-breaking process in the molding phases sequence and relies on a mold with a “double-ring” which opens completely at the end of the work cycle, characterizing the final product, making it easily recognizable and associated with the production process used.

It is precisely from this mold-process combination that comes the high productivity and freedom in the sole design.

Achieving the “Patent of Invention” in Italy, Germany, United States, China, India, Russia, Turkey and Brazil confirms the authenticity of the technology and further strengthens the position of Stemma, which today boast 25 systems already installed with the predisposition for the “PLUS2” system and the ownership of a further patent (“SWAP” system) for the production of three-density soles made entirely on the same molding plant, without the use of pre-molded rubber or TPU treads.

STEMMA reaffirms its vocation as an innovative company with solutions capable of satisfying the increasingly complex needs of an ever-changing market.