Start Publications Sprayable hot melt waxes as water repellents for oriented ...
Attension

Sprayable hot melt waxes as water repellents for oriented strand board

Year: 2019

Journal: Int. Wood Prod. J., Volume 10, page 102–110

Authors: Lotter, Barend T.; Evans, Philip D.

Organizations: Mary and David Macaree Fellowship Award; Viance; Tolko; FPInnovationsGerman Research Foundation (DFG); Government of British Columbia

Keywords: Oriented strand board; molten waxes; spraying; water repellents; thickness swelling; water absorption; contact angle; melting point

Oriented strand board (OSB) experiences undesirable thickness swelling when it absorbs water. One solution to this problem is to treat OSB with water-repellents containing waxes. However, aqueous water-repellents cause unwanted surface roughening of OSB, and there are environmental concerns with solvent-borne water-repellents. An alternative solution to these problems is to apply water-repellent waxes as hot-melt systems that contain no water or solvent. Molten waxes were sprayed onto the surface of hot OSB samples, and the water absorption and thickness swelling of treated OSB was assessed. There were no definitive relationships between properties of waxes and the water-repellency of treated OSB, but the most effective treatments were blends of beeswax, which is polar, and a strongly hydrophobic paraffin wax. These treatments reduced the irreversible thickness swelling of OSB samples and have potential as cost-effective post-treatments to improve the short-term moisture resistance of OSB, and possibly other wood composites.