The objective of this study was to evaluate the ability of molasses, a low cost by-product of the sugarcane
extraction, for improvement of the physicomechanical properties of old corrugated container (OCC) recycled
paper as a dry-strength agent. The influence of fiber beating on the enhancing effect of molasses was
also investigated. Five dosages (0%, 5%, 10%, 15%, and 18%) of molasses and 3 levels of freeness (420, 400,
and 320 mL CFS) were used as variable factors. For each treatment, 6 handsheets, each having an area of
200 cm2 and basis weight of 120 g/m2, were made. The experimental results showed that except for the
case of tear index, the increase in mechanical and physical properties were considerably higher than control
(untreated) samples. Significant changes of tensile and burst indices, breaking length, and air resistance
were observed after the addition of 18% molasses. From a statistical viewpoint, the addition of
molasses had more positive effects on the above-mentioned properties, compared to the fiber beating.
However, at a certain dosage of molasses, with increased beating, the strength properties were improved
remarkably. This is due to the molasses adsorption efficiency, which depends on the specific surface of
particles. The water retention values (WRV) were moderately increased by applying molasses, however
with increasing dosage the WRV was improved. From these findings, it is concluded that molasses is a
promising dry-strength agent and it can also be used as a replacement for cellulosic fibers. This conclusion
is in good agreement with the previous research articles, which introduced molasses as a new additive
in papermaking.