EFFECTS OF BUTYLAMINE TREATMENT ON CELLULOSE FIBERS DURING RECYCLING OF OLD CORRUGATED CONTAINERS (OCC)

Abstract

This study aimed to determine the effects of butylamine treatment on cellulose fibers during the recycling processes. Three recycling stages have been carried out and two different butylamine (Ba) treatments (5.0% and 7.5%) were applied to old corrugated containers (OCC) papers during recycling. After each recycling process, papers were produced and the mechanical and optical properties of these papers were measured. SEM images and FTIR spectra were taken and the crystallinity index of the cellulose fiber was calculated by the XRD peak height method. Some improvement (11.0-15.2%) in paper brightness with the Ba treatment was realized in the third recycling stage, while yellowness values typically decreased by 1-2 points. Chemical treatments resulted in definite differences in water absorptiveness (Cobb value) for papers. The highest water absorptiveness of 160.0 g/m2 was observed with a 7.5% Ba treatment in the second recycling stage (75Ba2), indicating a value about 15.6% higher than that of the control. The highest tensile and burst indices were observed with 7.5% Ba treatment in the third recycling stage, indicating approx. 28.7% higher tensile and 34.5% burst indices, compared to the control at similar recycling stages. In contrast, the highest tear strengths of 4.54 Nm2/g, followed by 3.86 Nm2/g, were observed for untreated samples in the second and first recycling stage, respectively. The butylamine treatment in the recycling processes increased the cellulose crystallinity more (1.3%), compared to the control. It seems that the strength properties of recycled paper, such as tensile and burst, are closely related to the individual fiber strength and fiber bonding potential, which are typically reduced in recycling, but could be improved by Ba treatment.