The Effect of Steaming Time and Temperature on the Longitudinal Permeability of Black Walnut

Abstract

Longit~~dinal permeability to water of black walnnt sapwood and heartwood specimen pl11gs \vas deterinined before and after steam treatments for 1, 2, 3, and 4 h and.two teniperati~res (100 C and 115 C).Steaniing heartwood specimens at 115 C gave three times greater increase in longitudinal permeability than steaming at 100 C .Also, steaming I~ea~.t\r.oodspecimens at 115 C for 3 11 gave the greatcst and most significant increase (560%) in longitudinal perineability of all other steaming times (which averaged about 90% increase ) .Ho\ve\-er, stc~a~n treatlnent cansed very little change in longitntlinal per~ileabilit~ of sapwood.Stcanling at 100 C for 4 h reduced the ~.;itio of longitudinal permeability of sapwood to Ilcart\voocl fro111 21,000 to ;tpproxi~natc.ly 10,000.Steaming at 115 C for 4 h reclncetl this l-atio to about 4,000. ISTRODUCTIONThe purpose of this study was to deterp,lack walnllt ( ~~~l ~~~ nigra L. ) is a 111ine whether steaming improves the longi- slobv-drying, valual,le hardwood.~l t h ~~~h tudinal permeability of black walnut.Black Dr!, Kiln Opercltor',s Rlanual (Raslllus-""lllut pits do not have tori to cause pit sen 1961) apprOxilnately 2 aspiration, but the wood has abundant ex-