The masters in making durable, waterproof rubber boots with minimal waste.
What It Takes
In terms of construction, a rain boot is a whole different animal than a leather boot. To make these boots, we needed a partner factory that could compression-mold our custom lug outsoles, vulcanize rubber, and test that each boot is truly waterproof. As is our style, we sought out the industry experts. Our connections led us two hours west of Shanghai to New World Rubber in Suzhou.
How It’s Made
Rubber arrives at the facility in large blocks, ready to be ground, melted, and mixed to customer specifications. Ours is a 100% REACH-compliant recipe, meaning it abides by the European Union’s REACH regulation, which is designed to protect humans and the environment from hazardous chemicals. Once mixed to spec (more on that in a moment), the rubber is flattened and stretched to uniform thickness. The individual pieces of rubber are then die-cut according to the pattern of the boot’s upper. Here’s where there’s a bit of a problem—there’s a ton of extra rubber left over from the sheet that’s been cut. What’s a factory to do? Well, New World Rubber has a pretty good idea: They grind it up, melt it down, and add it back to the main batch. Their research shows it can be reincorporated at a proportion of up to 40% without any measurable loss in quality, so that’s their recipe to make the sheets in the first place. This means our boots are made with 40% post-industrial recycled material, and it all comes from the factory’s own waste-diversion efforts.
Our custom-designed lug outsoles are created by heat-compressing the rubber in molds. To make the uppers, workers stretch the rubber pieces and the liners to fit the metal lasts, apply the elastic gores to the sides, hand-wrap the trim along the top edge of the shoe, and apply the outsole—all before going to QC checks. But they aren’t finished yet.
To make the most durable, waterproof rubber that won’t crack when it flexes, they use a process called vulcanization. A quick sulfur spritz and an hour of high heat and high pressure make for a verifiably waterproof boot. After they cool down from the autoclave, every single boot gets a submersion test to prove their level of puddle protection. It’s a small step, but when it comes to major curbside water currents, there’s a big difference between wet socks and dry ones.
The Factory
Their technical prowess drew us in, but it was ultimately their REACH compliance and materials recycling that made us certain of this partnership. As an added bonus, they use biomass pellets where possible to replace other fuel sources to heat their steam boilers.
