Natural fibers derived from Coi (Streblus asper Lour.) and their behavior in pulping and as paper

Abstract

The Siamese people utilized the bark of the Coi tree (Streblus asper Lour.) to manufacture paper approximately 330 years ago. However, there are no studies yet related to the chemical properties of Coi bark as well as the morphological properties of Coi bark fiber and Coi pulp fiber. This research paper discussed such properties of Coi bark. The results indicated that Coi bark possessed a chemical composition that could potentially be used for pulp production, although it contained a high value of ash content, due to many calcium particles in the bark. Even though Coi pulp fibers were very long and stiff, with small lumens and thick cell walls, they could be felted naturally on a washing screen to make a strong wet sheet. This was due to a high felting power of fibers derived from a high value of fiber length and slenderness ratio. Therefore, the handsheets produced from Coi pulp fiber were obtained without chemical and beating treatments. These observations mean that both the archaeological and industrial applications of Coi bark, i.e., an ancient Samud Coi preservation and a new potential source of pulp fiber, are possible.