Wood warping is a deviation from flatness

Flatness (manufacturing)

In manufacturing and mechanical engineering, flatness is an important geometric condition for workpieces and tools.In the manufacture of precision parts and assemblies, especially where parts will be required to be connected across a surface area in an air-tight or liquid-tight manner, flatness is...

 as a result of stresses and shrinkage from the uneven drying

Wood drying

Wood drying reduces the moisture content of wood before its use.There are two main reasons for drying wood:...

 of lumber

Lumber

Lumber or timber is wood in any of its stages from felling through readiness for use as structural material for construction, or wood pulp for paper production....

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The types of wood warping include:

• bow : a warp along the length of the face of the wood
• crook: a warp along the length of the edge of the wood
• kink: a localized crook, often due to a knot
• cup: a warp across the width of the face, in which the edges are higher or lower than the center of the wood
• twist: a distortion in which the two ends do not lie on the same plane

Wood warping costs the wood industry

Industry

Industry refers to the production of an economic good or service within an economy.-Industrial sectors:There are four key industrial economic sectors: the primary sector, largely raw material extraction industries such as mining and farming; the secondary sector, involving refining, construction,...

 in the U.S.

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 millions of dollars per year. Straight wood boards that leave a cutting facility sometimes arrive at the store yard warped. This little understood process is finally being looked at in a serious way. Although wood warping has been studied for years, the warping control model for manufacturing composite wood hasn't been updated for about 40 years.

A researcher at Texas A&M University

Texas A&M University

Texas A&M University is a coeducational public research university located in College Station, Texas . It is the flagship institution of the Texas A&M University System. The sixth-largest university in the United States, A&M's enrollment for Fall 2011 was over 50,000 for the first time in school...

, Dr. Zhiyong Cai, has researched wood warping, and was working on a computer software program in 2003 to help manufacturers make changes in the manufacturing process so that wood doesn't arrive at its destination warped after it leaves the mill or factory.