The Influence of Drying Conditions and Other Factors on Twist and Torque in <i>Pinus Radiata</i> Studs

Authors

  • J. F. G. Mackay

Keywords:

Kiln drying, seasoning, steaming, high temperature drying, drying under restraint, degrade, warp

Abstract

Pinus radiata studs of cross section 4 X 1 1/2 inch, sawn to enclose the pith, were dried in conditions of high and low temperatures, high and low air velocities, with and without presteaming, and with and without mechanical restraint. The resultant twist and torque values were measured and it was found that torque developed during drying was negatively correlated with drying rate. The results are interpreted in terms of the elastic-plastic properties of wood during drying. Torque values were used to calculate the equivalent loads required to restrain packs of this timber from twisting during drying and these compared well with optimum loads derived empirically in commercial trials.

References

Balodis, V. 1971. Twist in seasoned boards from plantation thinnings. Presented at the 15th IUFRO Congress, Gainesville, Florida.nChow, S.-Z., and K. J. Pickles. 1971. Thermal softening and degradation of wood and bark. Wood Fiber 3(3):166.nGoring, D. A. I. 1963. Thermal softening of lignin, hemicellulose, and cellulose. Pulp Pap. Mag. Can. 64(12):T517.nKoch, P. 1971. Process for straightening and drying southern pine 2 by 4's in 24 hours. For. Prod. J. 21(5):17.nMackay, J. F. G., and B. L. Rumball. 1971. Drying of distortion prone juvenile core radiata pine for house studs. Aust. Timber J. 37(6):43.nMackay, J. F. G., 1972. Plasticizing distortion prone softwood studs prior to high temperature seasoning. For. Prod. J. 22(6):27.n

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Published

2007-06-05

Issue

Number 4 / Winter 1973

Section

Research Contributions

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