Commercial Production of Tannins from Radiata Pine Bark for Wood Adhesives

This paper reviews available technologies for production of tannins from radiata pine bark for wood adhesives, then identifies the technical factors critical to commercialisation. As a renewable resource, tannins from pine bark are technically able to replace phenol and resorcinol, derivatives from the petrochemical industry, as wood adhesives. However, no commercially successful production process has yet been developed, largely because of the high processing cost and the problems associated with achieving both high production yields and appropriate quality of tannins for wood adhesives. A sulphited tannin extraction process was examined to analyse the economic and market feasibility of tannin extraction. Results indicate a limited commercial potential to replace phenol, but a more promising potential to replace resorcinol which can reduce gluing costs in engineered wood products.