late last summer the guys at Weinbrenner boots filled me in on a secret project they were working on. They explained to me how they invested a bunch of cash into a few new machines that can do better direct attach process. If you don’t know what direct attach or never heard of it here’s a little rundown.
As the name suggests, the direct attach process is used to mold the sole directly to the upper material, eliminating the need for gluing or sewing to produce a finished shoe. Direct attach requires that the upper is secured to the top of the mold, and the polyurethane system(s) is injected into the mold cavity. For dual density direct attach, a dummy last is used to form the outsole, and the upper is secured into the mold prior to midsole injection. Scrap produced using a direct attach process is very expensive due to the fact that an entire shoe is wasted. It is also very difficult to complete a post-mold finish process on direct attach unit soles without affecting the upper portion of the shoe. For these reasons, mold release agent selection is critical. Direct attach mold release agents must produce a defect free urethane part, as well as impart a uniform gloss appearance. Gloss requirements are defined by the manufacturer, but can cover a broad range from low (matte) to high (shiny). Other important performance attributes for direct attach release agents include release, low build-up in the mold cavity, and dual density adhesion.
The week of thanksgiving I received the first pair to roll off the production line. Opening the box for the first time I was shocked. I did not expect to see such a well-built boot. I have to mention this before I go any further. THE WHOLE BOOT IS AMERICAN MADE! It would be another whole week before I put them on my feet and still another four weeks before I could organize the time for a real wear test. Watch part one for a full boot desription. Part two is the wear test synopsis.