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Title: Chapter 08 Drying Defects

Source: USDA Agricultural Handbook AH-188: Dry Kiln Operator's Manual

Author(s): Ward, Simpson

Publication Year: 2001  View PDF »

Related Publications: view

Category: Agricultural Handbook

Abstract: The success of a company and the livelihood of the dry kiln operator may depend on knowing the causes of defects in lumber and methods to prevent their occurrence. Since some defects are not observed in green lumber and are first noted after the drying operation, they are often called drying defects even though the defects may have started in the tree, log, or green lumber. Defects that develop in dry wood products during machining, gluing, and finishing operations may also be blamed on poor drying practices. A drying defect is any characteristic or blemish in a wood product that occurs during the drying process and reduces the productís intended value. Drying degrade is a more specific term that implies a drying defect that lowers the grade of lumber. Every year, drying degrade and other drying defects cost the softwood and hardwood lumber industries millions of dollars in lost value and lost volume caused by poor product performance. When unexpected defects appear in dried wood products, their cause is often blamed on the drying operation. The purpose of this chapter is to describe the various types of defects that can occur in dried wood products and to show how these defects are related to the kiln-drying operation.

Keywords: Dry Kiln Operator's Manual Dry Kiln Operators Manual

File size: 3,227 kb(s)

Date posted: 06/10/2009

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