The research object is the development of compositions that ensure the manufacturability of products from a composite material based on secondary thermoplastic polymers. Methods. The methods of experimental studies of the hardness of materials and products in laboratory and production conditions have been implemented. To determine the composition of the plasticizer, experimental studies were conducted by varying the ingredients and their quantities. Results. The problem of reducing the hardness of thermoplastic polymers has been solved; the products have been compared in terms of rigidity with the basic version manufactured at the production site of the Neocomposit LLC plant. (Russia, 625001, Tyumen region, Tyumen, Krasnooktyabrskaya st., bldg. 14, apt. 162). The results have shown that adding the developed plasticizer composition to the polymer-sand mixture allows reducing the rigidity of the composite material by 4 times.