Single polymer composite sheets from polypropylene nonwoven fabric and films. Influence of processing conditions on final properties

Single polypropylene (PP) composites from a film/nonwoven fabric/film was obtained by hot calendering in order to develop recyclable, flexible, and low-cost sheets. Processing temperature (T-p) influence on morphology and mechanical properties of developed single composites was analyzed. Two different values of roll temperature (140 and 150 degrees C) were studied, keeping constant rotation speed and rolls distance. Results revealed notable differences in materials microstructure induced by a difference of only 10 degrees C in T-p. Sheets obtained at 140 degrees C presented a well-defined film/nonwoven fabric/film structure, meanwhile the highest T-p led to a greater melting extent of external films which penetrate into the fabric, creating a more compact structure. Moreover, results confirmed that changes in T-p can induce a differential mechanical performance showing higher strength, and ductility in sheets processed at 150 degrees C. Homogeneous sheets with good mechanical behavior, proper nonwoven fabric/films adhesion, and uniform thickness were obtained.