"Realizzazione scarpe prototipi sportcasual uomo materiali Bio-degradabili"

Due to the amounts of chromium in the leachate resulting from leather leaching tests, chromium sulfate tanned leather wastes are very often considered hazardous wastes. To overcome this problem, one option could be recovering the chromium and, consequently, lowering its content in the leather scrap. With this objective, chromium leather scrap was leached with sulfuric acid solutions at low temperature also aiming at maximizing chromium removal with minimum attack of the leather matrix. The effects of leather scrap dimension, sulfuric acid and sodium sulfate concentration in the solutions, as well as extraction time and temperature on chromium recovery were studied, and, additionally, organic matrix degradation was evaluated. The best conditions found for chromium recovery were leather scrap conditioning using 25 mL of concentrated H2SO4/L solution at 293 or 313 K during 3 or 6 days. Under such conditions, 30-60 ± 5% of chromium was recovered and as low as 3-6 ± 1% of the leather total organic carbon (TOC) was dissolved. Using such treatment, the leather scrap area and volume are reduced and the residue is a more brittle material showing enhanced anaerobic biodegradability. Although good recovery results were achieved, due to the fact that the amount of chromium in eluate exceeded the threshold value this waste was still hazardous. Thus, it needs to be methodically washed in order to remove all the chromium de-linked from collagen.

Il prodotto oggetto di valutazione consta di una serie di campioni di tomaia e di calzatura finita, manufatti nell'ambito del progetto europeo CEC-made-shoe("Custom, environment and comfort made shoe", EU FP6, Integrated Project, Contractnumber507378 - 2, cfr. All.1 - capitolato tecnico del progetto, pagg.62-63), ed in particolar modo durante la fase di validazione delle ricerche sperimentali condotte da CTCA - Centro Tecnológico do Calçado, partner di ricerca e sviluppo tecnologico nel WorkPackage 3 (Materials). ITIA-CNR, coordinatore tecnico del progetto, ha infatti effettuato l'attività di validazione integrata, presso l'impianto pilota ad elevata automazione per la produzione di calzature personalizzate, attraverso la concezione e la prototipazione rapida di una serie di campioni atti a testare: o Manufattibilità: taglio, scarnitura e spaccatura; o Assemblabilità: operazioni di (pre)montaggio, cardatura, incollaggio e finitura dei nuovi pellami e materiali per inserti e rinforzi sviluppati nei Workpackage di RTD.