MANILA — The Department of Science and Technology (DOST) said Tuesday that tannins or extracts from locally available trees could be ingredients for making plywood glue.
The agency explained that tannins are organic substances normally present in barks and other plant tissues, which are commonly used to make leather and wood adhesives.
“Some are used as tanning agents for leather products, clarifying agents for wine production and ingredients in cosmetics & pharmaceuticals products,” said Rebecca B. Lapuz of DOST — Forest Products Research and Development Institute (FPRDI).
Based on the agency's initial findings along with other experts, experimental plywood bonded with tannin-phenol formaldehyde adhesives passed the bond quality requirement of ISO 12466-2 (2016), with minimum amount of formaldehyde emission released.
Some of the crude tannin extracts were found moderately effective against fungi and insects when applied as wood preservative, it added.
The initial findings is a collaborative project of DOST-FPRDI, Switzerland-based Bern University of Applied Sciences (BFH), Philippine Coconut Authority — Zamboanga Research Center (PCA-ZRC) and Visayas State University (VSU), which was funded by the Swiss National Science Foundation.
The project was part of the research program “Pinoy Tannin: Development of a Sustainable Tannin Extraction in the Philippines” that evaluated the most effective way to extract tannins.
Led by Dr. Sauro Bianchi of BFH, the program aims to develop a low-cost and sustainable tannin extraction technology among local communities in the Philippines, and the use of local tannins as substitute for conventional adhesives and preservatives for the country’s wood industry.
The institute led the project on the characterization of tannin extracts from agroforest residues such as barks, coconut husks and shells. It also studied its application in wood adhesives and wood preservatives.