The S-D-R (Saw-Dry-Rip) process is a proven method of reducing warp in manufacturing hardwood studs. It has been assumed that its success is partially due to the stress relaxation caused by high-temperature drying. Implementation of this S-D-R process in the Appalachian region has been limited as few mills in this area have this drying capability. The purpose of this study was to investigate the effectiveness of high-temperature and steaming treatments before solar and air drying S-D-R flitches on reducing warp and to determine the cost of application of successful methods.
An initial study was conducted to establish the duration of treatment required to relieve growth stresses in short S-D-R flitches. Steaming for 15 hours resulted in a substantial decrease of average stress. Steaming times of 15 and 20 hours and high-temperature durations of 7 and 15 hours were chosen for treating green S-D-R flitches.
S-D-R flitches were divided among the four treatments and a control group. One third of the flitches from each group were subsequently dried in a solar kiln; the rest were air dried. All flitches were then ripped into 2 x 4's and bow, crook, and twist was measured for each stud.
A comparison by the percentage of studs rejected from No. 2 dimension because of warp showed no significant difference between any treatments (including the control) or between drying methods. Comparisons based on actual amount of warp found small differences between drying methods and between treatments, depending on the type of warp considered. / Master of Science
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/82881 |
| Date | January 1982 |
| Creators | Weik, Bruce R. |
| Contributors | Forest Products |
| Publisher | Virginia Polytechnic Institute and State University |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | en_US |
| Detected Language | English |
| Type | Thesis, Text |
| Format | viii, 63 leaves, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | OCLC# 9503029 |
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