Bast fibers of Mitsumata (Edgeworthia papyri fera Sieb. et Zuce.) were cooked forpreparing paper making pulp using ammonium oxalate solution under various concentrations (Table 1) and temperatures (Table 2). Pulping tests after immersion of raw materials inammonium oxalate solution at room temperature (20°C) were also done (Table 3).
It was shown that ammonium oxalate gives much stronger pulp of higher yield than those obtained by the conventional alkaline process (Fig. 1-6). The immersiontreatment of bast fibers in ammonium oxalate solution at room temperature was also effective formaking pulp enough to give high strength of paper (Fig. 7-9).
These results indicate that ammonium oxalate acts as an adequate solute to removethe pectic substances from the pectocellulosic plant fibers effectively and makes fibers tobe easily defiberized with few damages of fibrous construction.