Reverse proof loading as a means of quality control in lumber manufacturing

The determination of the strength distribution of a given structural grade of lumber from any chosen mill is of growing concern to the lumber industry. Lumber in the lower range of strength values is of prime interest. A reverse proof loading procedure, applied in bending, appears to result in a more uniform product through elimination of the weak pieces resulting from inconsistencies within mill grading procedures, different levels of grader skill and variation in log quality. Experiments on 400 pieces of 2 x 4 No. 2 Dense KD Southern Pine involved loading 200 pieces to failure in bending and then reverse proof loading in bending the remaining 200 pieces. The reverse proof loaded lumber (RPL lumber) was then destroyed in bending. The probability of failure was calculated for the first 200 pieces (the control lumber) and compared to the probability of failure of the RPL lumber. A reduction of strength procedure was then performed on the RPL lumber data. These results indicated that the reverse proof loading procedure would account for a 30.5% drift in the quality of manufactured lumber.

Name thesis:degree_name

M. S.

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Agricultural Engineering

Department dc:contributor.department

Agricultural Engineering

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1979

Author dc:creator

• Marin, Lisa Anne

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10919/118892

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/118892