what is used to construct shoe outsoles

As a New Midsole Material Launches has Adidas Boost Foam met its match?

Adidas and BASF turned heads with the introduction of the futuristic Boost Foam technology. The unique midsole material has performance advantages and a distinctive look. Boost foam is actually a new formulation of a common plastic, TPU. TPU or Thermoplastic poly-Urethane Boost is “blown” meaning the chemical engineers at Adidas and BASF have figured out a way to introduce air bubbles into the plastic making a new TPU foam.

The challenge of making Boost TPU foam midsoles

Steam Expansion Equipment to make Adidas Boost.

The texture, while distinctive, makes all Boost midsoles look alike. This distinctive look is great for marketing launches but designers need the ability to make shoes look different year to year.

Boost foam also has a color issue. The TPU foam cannot be molded in color so the midsoles must be painted. Painting midsoles adds cost to the product and even flexible paint can be scratched off or chipped off the foam surface.

The Boost midsole also requires special steam expansion equipment not found in the standard shoe factory.

A new midsole foam better than Boost?

New foam uses standard equipment

Today we visited an EVA pressing factory with a new compound in development. This new midsole foam is a mixture of EVA and TPU. This new foam has the resilient, wrinkle-free feeling of Boost foam but it can be made with standard EVA forming machines. The foam maker is hush hush about the exact compound but he tells us the new foam is about 30% TPU and 70% EVA.

This new midsole compound is lighter than standard EVA and can be molded in any color like standard EVA midsole foam. This new EVA TPU foam is a little more expensive than standard EVA but costs much less than Adidas TPU Boost foam.

new Midsole Foam
New foam with co-molded rubber bottom