A production process of mixed yarns and mixed yarns obtained from circular and or sustainable and or biodegradable textiles within any textile industry and or adapted in the machines within spinning mills. This makes possible a very large combination of different types of textile yarn mixtures and a wide range of weights of mixed sustainable and or biodegradable yarns, to meet and create new demands for sustainable and circular textile products. The process described for injection of compressed air is the combination and mixing of sustainable and circular and or biodegradable continuous filament yarns with biodegradable, and sustainable natural and/or artificial spun yarns, bringing technology to the products in line with the sustainability of the environment. This makes possible a definitive solution in ocean contamination by synthetic fibers and prevents much of the artificial textile fibers from fabrics and clothes, which release their cut fibers during industrial and domestic washing.