3D Printing of Pads on Lasts Utilized in the Production of Custom-Made Comfortable Footwear

The study investigated the process of adjusting the shape of the footwear last using solid modeling elements (individual pads) manufactured through 3D printing. Based on a comparative analysis of the results of anthropometric foot studies with the parameters of existing footwear lasts available on the Ukrainian market, the rationale for improving the method of correction lasts using individual pads in mismatched anthropometric zones to achieve consumer foot comfort is substantiated. A schematic diagram of the transverse cross-section of the foot-lasts-pads-footwear system is provided. The study obtained dependencies of the calculated radius of the outer contour of the pad on the thickness of the upper material of the footwear. The anthropometric regions of the foot that most commonly require adjustment in existing lasts to achieve the production of custom-made comfortable footwear have been identified. The method of adjusting the shape of the last has been improved based on the individual parameters of the customer's foot, using pads manufactured using 3D printing technology. The interdependencies between stress and deformation under tension have been established, and the strength limit of polymer material samples for corrective pads obtained through 3D printing has been determined. The rational technological parameters of the 3D printing process using elastane material for corrective pads on lasts have been determined and implemented in the production of custom-made footwear.