Methods of fastening soles

One of the most durable fastening methods. The sole consists of two parts. The inner part (rubber or leather lining) is stitched to the welt, and the outer part (rubber sole) is glued to it. The continuity of the joints is achieved through the use of a strong nylon stitch. The sole is made of wear-resistant microporous material.

The sole is attached to the edge of the shoe with glue. The sole's sides are then stitched on a special double-thread stitching machine using a particularly strong Lavsan thread. The double-thread stitching method provides additional strength and prevents the seam from unraveling if the thread is damaged. Punctures in the leather are sealed with knots and further treated with shoe wax to prevent moisture from penetrating the shoe.

This method creates a strong, monolithic bond between the rubber sole and the upper. The raw rubber compound is molded in a special mold that matches the contour and profile of the sole. The molded sole is vulcanized and attached to a preform, which is then tightened onto the insole. Vulcanization occurs at the appropriate temperature and pressure.

The classic fastening method provides footwear with strength, reliability, and a neat appearance, emphasizing elegance. Adhesive-fastened footwear uses soles made of various materials (rubber, TPR, PU) bonded to the upper with glue. These shoes are lightweight, flexible, and highly water- and wear-resistant. However, they lack impact resistance.

A distinctive feature of the injection-molded method is that the process of attaching the shoe's sole is combined with its molding. The sole is bonded to the upper by penetrating (adhering) polyurethane into the upper leather and insole materials, increasing the bonding area between the upper and the lower material tenfold. This creates a seamless connection between the shoe's sole and the upper. This method is progressive and reliable, making the shoe exceptionally resistant to moisture and aggressive environments, as well as lighter and more flexible, which overall improves walking comfort.

In the production of injection-molded footwear, the stitch-and-injection method is dominant. Despite the relatively expensive injection tooling, this method, due to its high productivity and low labor intensity, is widely used for producing a stable range of footwear. The stitch-and-injection method is the same as the injection-molded method, but uses a soft, set-in insole.