Search

A soda-anthraquinone process was used to obtain pulp from six year old Teak (Tectona grandis) wood, farm grown in northern Costa Rica (San Carlos, Alajuela). The experiment used statistical factorial design with two levels and three variables. The variables were cooking time, cooking temperature and sodium hydroxide concentration in mass percentage; the fixed variables were bathing relationship (1/6), initial quantity of dry wood (140,0 g) and anthraquinone concentration in mass percentage (0,1 %). Answer variables were mass yield and pulp lignin content (both on dry base percentages). Best results were obtained at a temperature of 160 °C, cooking time of 45 min, and sodium hydroxide concentration of 7 % with a pulp mass yield of 45,5 % and delignification of 98 %. This time is shorter than that used in similar research and the temperature and sodium hydroxide percentage, despite being low, can be diminished further according to the results. The pulp was light beige, and showed no remaining chips or splinters; therefore, it can be stated that the soda-anthraquinone pulping was effective for wood cooking and pulp production, since it is very selective eliminating lignin without harming the cellulose, which gives a high yield. [ABSTRACT FROM AUTHOR]

The technical feasibility of pulping and papermaking of the "paste" (Luffa cylindrica Roem) from waste of the production of bathroom products in Costa Rica was studied. Two pulping processes were employed to produce and characterized pulps for papermaking: hydrothermal and thermochemical with 2 % soda. Characterization included physical, mechanical, optical and chemical properties. Principal results showed high strength properties, low density, low brightness and high opacity, making the pulp suitable for papermaking fine papers, printing and packing uses. In spite of having a short to median fiber length (around 1305 μm), the testing Luffa sheets presented a strong fiber-fiber union, generating a high mechanical resistance, added to a light beige color and high opacity, similar in mechanical resistance to testing sheets produced with long fibres (greater than 3 000 μm) like banana fibres (Musa Giant Cavendish). This study is one of a series of investigations led by the Laboratory of Forest Products of the University of Costa Rica looking for a better agroindustrial waste management, a decrease of the environmental impact and to reach a sustainable development as defined by Costa Rican policies. [ABSTRACT FROM AUTHOR]