We performed a set of experiments using our new 50-kW RF kiln at the Penn State Forest Resources Laboratory in November 2017.

International Standard of Phytosanitary Measure No. 15 (ISPM-15) requires phytosanitation of wood packaging materials (WPM) used in international trade. WPM is associated with most global merchandise trade, and ISPM-15 affects more trade by volume than any other phytosanitary measure. Our goal is to provide faster and more cost efficient method for meeting ISPM-15 Standard for WPM and other wood commodities.

Radio frequency (RF) technology, which was recently approved under ISPM-15, is a sustainable, economically competitive solution to replace methyl bromide (MeBr) for treatment of WPM used in international trade. Our team developed an innovation to RF heating, which will be a game changer in the economic competitiveness of this technology for phytosanitation of WPM. Our research shows that our innovation in RF treatment resulted in:

1) More uniform heating reduces power consumption by 40%; RF heats wood material volumetrically, and in a cost-effective way keeps electrical power consumption to a minimum while providing markedly improved heating uniformity, thereby reducing operational energy costs;

On thermal image below we can observe the heating consistency obtained for treated wood.

Wood load in RF kiln chamber

2) Greater processing time efficiencies, increasing output capacity for the treating company, which should yield a higher return on capital investment; during tests performed from November 2017 to March 2018, we managed to shorten the time of RF treatment for White Pine cants: from 268 min to 150 min, and for White Ash stringers: from 258 min to 129 min.

3) Reduces moisture loss of the treated wood to only 1-3%, preventing damage from excess moisture losses;

4) Possible use as part of in-line (lean) manufacturing system, lowering labor costs and reducing inventory that has to be warehoused for improved cash flow in pallet manufacturing.

Our team is making efforts to provide the optimum parameters of RF technology, which maximizes heating uniformity and minimizes treatment duration for common wood species used to construct WPM. We plan to work with pallet manufacturing partners to conduct cost/benefit analyses and prepare value propositions for implementing RF technology.