Method to Control Post-Harvest Wood Color

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When producing wood lumber and veneers such as black walnut, the scarcity and dark, rich colors of the woods result in high market values for the end product. Likewise, woods such as yellow poplar and hard maples have high market values due to the lightness of their color. Unfortunately, the cost to handle and process the woods in order to obtain the desired result is also high. For example, to darken woods such as black walnut, the cut trees must be maintained wet and then steamed or cooked for long periods in order to soften and facilitate the process of "color maturation" for the wood. The wood must then remain wet for 24 to 48 hours for the wood to completely darken or lighten.

Purdue University researchers have developed a chemical based method to control the post-harvest physiology of wood and lumber. Damage induced biochemical signals that lead to undesirable wood coloration changes can be induced or inhibited during processing that takes place after field harvesting. The technology can prevent the discoloration of white wood lumber, such as yellow poplar and hard maples, or can induce dark coloration in woods, such as black walnut.

-Post-harvest process can be readily included in saw mill, lumber sorting, or veneer slicing operations
-In-line process provides shorter processing times with lower inventory levels while eliminating steam chamber equipment and off-line batch processing
-Low setup costs requiring relatively simple machinery
-Simple control systems lead to low operating costs

Potential Applications:
-Agricultural industry
-Wood processing
-Chemical analysis
Nov 2, 2007
Utility Patent
United States
Jul 10, 2012

Nov 2, 2006
United States

Nov 22, 2005
United States
Purdue Office of Technology Commercialization
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