Rationalization of the method for determining the shape retention of the shoe stiffeners

The article is concerned with the development of recommendations for rationalization the measurement methodology of determining the total and residual deformation of the stiffeners, regulated by quality standard GOST 9135-2004 “Shoes. Method for determining the total and residual deformation of the toe puff and stiffeners”. This technique has a number of disadvantages, which are as follows: - the standard inserts in the stiffeners, as a rule, do not correspond to their internal shape and size; - the scale factor is not taken into account when applying the same deformation load for shoes that have different average sizes; The disadvantages mentioned above can be eliminated without making changes to the design of ZhNZO-2 device, but only to the testing procedure and the equipment used for this. The article also presents studies of the residual deformation of natural leathers, cardboards and stiffeners, which show that the use of new equipment and changes in the methodology regulated by GOST 9135-2004 can significantly improve the accuracy and reliability of the results. The objects of study are genuine leather “Elite”, cardboard for stiffeners “Ledtrret 22” and stiffeners. The results of the work can be used as recommendations for improving the methodology and equipment for assessing the overall and residual deformation of the stiffeners.