Alkaline Treatment of Black Spruce Bark for the Manufacture of Binderless Fiberboard

Abstract

Black spruce bark from a lumber mill in eastern Canada was characterized for its chemical composition and suitability for the manufacture of fiberboard. The high holocellulose content and low lignin content indicated it contained a considerable amount of wood fibers. The bark was treated with 1% NaOH solution, pre‐heated with steam, and subsequently steam‐pressurized refined to produce fibers. The untreated bark was also pre‐heated and refined for comparison purposes. The fiberboards made from alkaline‐treated bark showed lighter color, higher internal bonding strength, higher modulus of rupture, and higher modulus of elasticity in comparison with the control panels. The thickness swelling of the panels made from treated and untreated bark was comparable. Pre‐heating before refining was an important stage for the manufacture of binderless fiberboards from treated and untreated bark.

Keywords:

• Black spruce bark
• alkaline treatment
• pre‐heating
• refining
• binderless
• fiberboard

The Natural Sciences and Engineering Research Council of Canada (NSERC) is acknowledged for awarding an Industrial Research Fellowship to Xinglian Geng.