E.V.A, THE BEGINNING OF THE END? THE PRECURSORS

2008 and 2012 are two important years in our sporting-good industry, Because these are first of all Olympic years. 

Secondly, every Olympic year unveils methods and innovations dedicated to the higher sport venue. 

In our Microscope, these two years are marking the rise of the precursors of the EVA replacement.

Brooks sports and NIKE are the ball opener in 2008, Scott and Adidas are the ride experience provider of the year 2012. See below, their story and promises. 

2008 Brooks Sports, Inc. announced that BioMoGo, the world’s first biodegradable midsole, is now available to consumers in the new Trance™ 8 premium support shoe. 

Brooks designed BioMoGo to biodegrade 50 times faster than conventional athletic shoe midsoles, making it one of the most significant sustainable technologies.   

 

later in 2012, Brooks created DNA, an innovative and uniquely adaptive cushioning system. By adapting to specific weight, pace, gait and running surface, DNA is promised to offer customized cushioning and adds a spring to runners steps.

Traditional cushioning takes a one-size-fits-all approach, but people at Brooks claim to know that each runner is different. Brooks DNA was developed to continuously tailor the level of cushioning to runners specific needs – even as they change during the run.

Brooks DNA is made up of a highly viscous non-Newtonian material or more simply put, a material that adapts to the specific force runners apply to it. 

Part of the brilliance is that this compound was engineered to perform at the molecular level (picture millions of resilient 'nanosprings').

2008 NIKE Lunarlon cushioning features a soft, yet resilient, foam core that is encased within a supportive foam carrier for lightweight, ultra-plush cushioning, springy response and support.

The innovative Lunarlon foam, invented by Nike, is 30 percent lighter than traditional Phylon and allows the force of impact to be more evenly distributed, which helps reduce painful pressure points on feet.

With Brooks and Nike technologies, I confess, it is hard for specialists, maybe real hard to consumer to distinguish a difference in between traditional compress molded EVA (Brooks case) or injected EVA (Nike case). 

There is certainly a felt experience with the softer encapsulated but invisible Lunar foam, while Brooks teases us with our ecologic awareness more than direct experience with a dramatic change of technical/physical product behavior.

I don't know if Adidas spotted the early weaknesses of his competitors?

But this simple close up of the Boost foam, visible, palpable, makes a courageous difference.

December 2012, Adidas claims the Boost TPU midsole has many benefits over the traditional EVA technology. 

EVA is a responsive material that compresses with each step and rebounds to return energy to the foot. 

Over time, EVA can wear down, requiring the runner to invest in a new pair of shoes

Boost technology eliminates this problem with thousands of energy capsules that store and release energy only when it’s needed— without losing integrity.

Boost technology eliminates another problem. your winter and summer runs have an incredible effect on traditional EVA, the colder the tougher, the hotter, the softer. 

With its formula, boost guarantee a similar ride.

I spent over 16 years of duty, a certain amount of time middle cutting shoe midsoles, wondering about constructions and additive cushioning systems. 

I always wondered how a runner can really benefit from the promises of performance given by the brands? 

before being in contact with the star compound,  I realized the numbers of fine layers you need to endure before being in contact to THE Promise. 

Bonding surfaces included, an average 100 $ shoe has 7 material layers over the midsole. This Picture tells how Adidas engineers paid another attention to increase as much as possible the closer contact to the foot. 

December 2012, Working with athletes, Scott always hear that they would like to run in lighter shoes, but are not willing to sacrifice any cushioning performance. 

So, they, (Together with I-Generator: engineering and design firm in Portland OR) found an alternative to the EVA foam used in most running shoes. 

SCOTT Aero Foam combines lightweight materials with a wear resistant compound, resulting in shoes that are lighter, have more cushioning and last longer than traditional running shoes. 

Again, I point out the difference in visible and tactile sensation compare to traditional EVA including outer surfaces of the Nike Lunar or Brooks latest DNA/BioMoGo foams. 

Scott Precursive Stance is valuable, the 2013 Kinabalu has been a very surprising ride experience at the Austin Running Event fair.

E.V.A, THE BEGINNING OF THE END? Part 1 : INDUSTRY REMINDER

Ethylene-vinyl acetate (EVA), also known as poly(ethylene-vinyl acetate) (PEVA), is the copolymer of ethylene and vinyl acetate. The weight percent vinyl acetate usually varies from 10 to 40%, with the remainder being ethylene.

EVA is an elastomeric polymer that produces materials which are "rubber-like" in softness and flexibility. The material has good clarity and gloss, low-temperature toughness, stress-crack resistance, hot-melt adhesive waterproof properties, and resistance to UV radiation. EVA has a distinctive vinegar-like odor and is competitive with Polyurethane in footwear applications. (source Wikipedia)

Footwear industry, back to the mid 70's envisioned the EVA Material as a solution in order to improve the overall comfort of active footwear. The first generations of running shoes fitted with EVA looked pretty much like the picture above. Mizuno Sky Race 1995 

The upper were generally a Mocassin construction, lasted in the forefoot over a dye-cut EVA Midsole and rubber outsole. The down-side of the cutting process lies in its binary look. An austere sand paper look.

In the same decade, I have been told That Brooks Sport were the very first company to compress- mold the EVA instead of the common dye-cut process. 

Unfortunately, I cannot prove myself right as I am still looking for the proven facts and Brooks doesn't seem to communicate this part of their history. 

This molding process opened a vast world of creativity in term of function and design. The heat of the mold melted the sand paper looked surface and turned it into a thin soft skin. We suddenly could create shapes and lines easily.

The other main material player of the 70's and 80's is the POLYURETHANE full sole as for the Adidas zx 8000 produced in 1988/89. 

The POLYURETHANE had fantastic characteristics of shape memory, due to its formula. The EVA is still generally loosing its dampening quality way faster than POLYURETHANE does. 

EVA has a minor density which makes it by far lighter than POLYURETHANE of that era. The Other downside of the POLYURETHANE were found in its weak resistance in keeping its original color (yellowing effect) and poor performance in Hydrolysis. Most of you might remember the midsoles breaking and powdering.

Once the compression molding process democratized, most Brands were sometimes combining EVA and POLYURETHANE in order to get the best of the two materials, mainly for functional reasons. 

In this case, Nike with the Nike Pegasus 1988 took the advantage of EVA for an overall lighter product at the forefoot. The POLYURETHANE guaranteed a long lasting heel cushioning. The air wedge embedding process also needed a POLYURETHANE environment until late year 2000.

1987 showed an other design/functional approach: a Stabilizer chassis called RSD. The Molding process of either EVA or POLYURETHANE (in this case) could fit with precision, different quality of Polymers together. Adidas ZX 820 Women.

Here is Another solution found at Adidas in order to improve the durable performance of EVA. 

A web was bonded over the EVA from top to the side of the midsole for a trampoline effect.

The story doesn't tell if this idea inspired brand SAUCONY for their GRID system, or vice versa? 

In a world of technologies, it is interesting to see how foams, in particular EVA and POLYURETHANE became a kind of a given standard to the average customer.  Here the nike air Max 1994.

Lets take the thought further, I would even see those foams as a platform of other visible technologies that became over time the more valuable additive systems and more precious in people's mind than the foam itself.  

I think it is an unfair lack of recognition to the foam. 

The visible air Max unit and its little sister the non visible forefoot air wedge were only additive richness and function to the product, never the reason why the shoe was more comfortable. 

until Adidas spring blade 2012 and Nike Vapor max 2016 , no active shoe cushioning system was available without foam.

Another example of foam being an interface in between the foot and the ground. Reebok Opus 3d foam 1997. 

Reebok gave a durability challenge to the EVA foam by removing the Rubber and claiming the foam is durable enough to withstand friction. 

But the stars of the picture are the Graphlite plate made of composite fibers and the unexpected shaped upper. 

Complex Mold processes, proved how the EVA is somehow flexible in combination of different characteristics. 

This Puma offers 5 variety of EVA within the same midsole, the M cell being bouncy, the O cell being cushy, a medial post being harder the white overall foam being medium and the ISS co molded plate for midfoot stability.

This shoe images the end of an era, the Lego blocks answering biomechanics in selected areas have been the pinnacle of the EVA combined evolution, far more complex than the dye-cut process. 

One question Though, was it better?