Thesis (M.S.)--Oregon State University, 1981. / Typescript (photocopy). Includes bibliographical references (leaves 75-77). Also available on the World Wide Web.

Thesis (M.S.)--Oregon State University, 1979. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.

Thesis--Wisconsin. / Vita. Includes bibliographical references (leaves 77-81).

Thesis (M.S.)--Oregon State University, 1985. / Typescript (photocopy). Includes bibliographical references (leaves 79-81). Also available on the World Wide Web.

A pilot study was conducted on the exhaust vapour which is expelled through the roof-ventilator stacks of a Moore cross circulation veneer dryer, in order to determine whether or not any by-products of commercial importance could be recovered from Douglas fir veneer while it is undergoing normal drying operations prior to the manufacture of plywood. Separate studies were made on the heartwood and sapwood veneer of this species. Some steam-distilled volatile oil was recovered from the stack gases, but because of the small amount which was collected, this material was considered to be of no commercial value. Recommendations have been made for future work in this field. / Forestry, Faculty of / Graduate

Although Engelmann spruce is being utilized on a commercial scale for plywood manufacture in this province, difficulties are still encountered in the manufacturing process. The most serious problems are the long drying time required at low temperatures for veneers and the frequently unsatisfactory nature of the glue bond. Complaints have also been voiced about the unique characteristics of Engelmann spruce veneer that render it susceptible to degrade in storage. Experience has shown that dried veneer stored under manufacturing conditions for only a few days will no longer form a good glue bond. The present study was initiated to investigate the causes behind these difficulties. Three factors were included: three maximum veneer-drying temperatures (358°F., 378°F. and 393°F.), sapwood and heartwood, and two periods of storage (3 and 30 days) in a fully dried condition. Two measures of glue-bond strength, breaking-load and percentage wood-failure, were used as indicators of glue-bond quality. These were determined by three methods of test: plywood- shear, glue-line cleavage, untreated and glue-line cleavage, treated. It was found that drying temperature and storage time, as studied, had no important effect upon the glue-bond quality. Sapwood veneer gave a lower breaking load but a higher percentage wood-failure than did heartwood veneer. The breaking load seemed to be a more reliable indicator for estimating the glue-bond quality than did the use of percentage wood-failure. / Forestry, Faculty of / Graduate

Thesis (M.S.)--Oregon State University, 1980. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.

Thesis (M.S.)--Oregon State University, 1983. / Typescript (photocopy). Includes bibliographical references (leaves 115-117). Also available on the World Wide Web.

Southern pine and Douglas fir veneer samples were dried in air under the following conditions: air temperatures were 350, 600, and 750°F; air velocities were 50, 100, and 150 feet per second, and angles of impingement of air against the veneer surfaces were 0°, 45°, and 90°. The resulting drying curves were compared with drying curves obtained under similar conditions using steam as the drying medium. Statistical analyses were performed to estimate magnitudes of differences in veneer drying times associated with the two drying media, the three angles of impingement, and the two species of wood. Air was found to be more effective than steam as a drying medium at the 350°F operating temperature. For the 600°F and higher operating temperatures, steam was found to be more effective than air. Under all drying conditions, Southern pine dried faster than Douglas fir. Effective heat transfer coefficients representing the convective effects of both heat and mass transfer associated with drying veneer were computed in two ways: based on the experimental data, and based on theoretical considerations. Experimental internal diffusion coefficients were also computed. Diffusion of water from the interior of the veneer to the veneer surfaces was found to be the controlling factor on the rate of veneer drying during all but a brief period in the initial stage of the drying process. / Graduation date: 1970

Graduation date: 1968