Production of Thai hand-made paper from industrial hemp barks

Industrial hemp barks were used to produce Thai hand-made paper. Five kinds of hemp barks were selected according to the age ranging from 90, 100, 110, 120 and 90-120 days old. The pulp from each type of barks was first separated from the unwanted fleshy part of the core, and then was made into thin sheets weighing 70+-5 g/square m. Each was further mixed with Kaolin, 15 percent of the total weight of the dried pulp. Next, it was made watertight by coating with Hercon, Chitosan, oxidized starch, animal glue, and Glucomannan. The physical and waterproof abilities of the paper was then tested by the standard measurement of TAPPI. The results showed that when peeling off the bark, 4.25 percent fleshy tissue of the core still remained with the peelings and 7.47 percent with the pulp. The pulp gained after boiling each kind of barks was 63.66 percent, 62.51 percent, 61.36 percent, 57.62 percent and 53.08 percent, the whiteness 63.64 percent, 64.86 percent, 64.37 percent, 66.02 percent and 65.04 percent, the opacity 80.97 percent, 81.53 percent, 84.58 percent, 80.77 percent and 79.83 percent, and the tearing resistance 284.61 percent 201.14 percent 163.44 percent 173.92 percent and 163.48 N square m/g respectively. Paper made from 90-day-old pulp tended to be better than those from the pulp of older barks. In addition, the coating with 2-6 percent Hercon could increase the waterproof level to 91.94 percent with 2 percent Hercon and 1-1.50 percent Chitosan only to 90.80 percent, and with 6 percent Hercon and 1-1.50 percent Chitosan up to 92.28 percent on average. However, to prevent the absorption of water, 2 coats of 1-1.50 percent Chitosan could activate about 17.35 percent, 6 percent oxidized starch and 1-1.50 percent Chitosan could do 49.76 percent, 3.7 percent glue from animal, coated 2 times, did 13.40 percent, and should be coated with Hercon to better waterproof, and added with Chitosan to increase toughness and strength. The paper coated with Chitosan, oxidized starch and animal glue was very tough and strong when dry whereas the paper coated Glucomannan was very tough and strong when dry and did not tear easily when wet.