Abstract
We investigated the effect of pulping processes on the strength properties of bamboo paper. Bamboo was pulped by hand and by the kraft process. Handsheets were formed from the pulps obtained and their properties were measured before and after accelerated aging. The pulp made by hand had a lower water retention and a higher initial viscosity than the kraft pulp. Paper made from the hand-made pulp had a considerably higher aging resistance than paper made from the kraft pulp. All the measurements revealed that acid-free paper made from the hand-made pulp retained its mechanical strength (especially folding endurance) better during accelerated aging than acid-free paper made from the kraft pulp. Retention of the folding endurance depended considerably on the retention of the zero-span tensile strength during sealed-tube aging. With the exception of zero-span tensile strength, hand-pulped and kraft-pulped acidic papers did not exhibit any significant difference in their mechanical properties. Although the paper made from the hand-made pulp had higher sheet strength than the paper made from the kraft pulp, both papers exhibited similar reductions in the surface pH during tube aging. Before and after accelerated aging, the paper made from kraft pulp produced by cooking at 170°C for 90 min had higher intrinsic fiber strength than the paper made from kraft pulp produced by cooking at 160°C for 60 min for both acid-free and acidic papers.
