During the manufacture of wood panel products, fillers are commonly added to wood adhesives to lower costs and give body to liquid adhesives and also reduce undesired flow or overpenetration into wood. The fillers used in wood adhesives are often neutral or weakly alkaline compounds that typically require no chemical reaction with curing agent, or other components. Fillers are mixed with other components prior to the application of resin on the surface of wood, wood veneer, or wood flakes. Fillers can be either organic (e.g., rye, wheat, walnut shell, and wood flours), or inorganic (e.g., calcium carbonate, calcium sulfate, aluminum oxide, or bentonites). Overall, fillers are low-cost materials for improving the properties of wood or even give it new functions.
Part of the book: Fillers