Screwdriving Torques in Particleboards
Abstract
Characteristics of torques for driving screws into particleboards were investigated in this study. Factors evaluated on screw seating and stripping torques (SET and STT) were pilot-hole diameter, embedded screw orientation, and particleboard (PB) material physical and mechanical properties such as material core density, particle size, and internal bond (IB) strength. Recorded torque–time curves, which illustrate the complete process of driving screws into PB materials, indicated that screw torques behave similarly in sides and faces of PB and that the whole screwdriving process can be described as a two-phase process. PB materials evaluated in this study had mean SET from 0.66 to 1.94 N-m, STT from 2.03 to 6.51 N-m, and STT-to-SET ratios from 2.5 to 5.0. Statistical analyses indicated that the SET and STT of driving screws into PB faces were significantly greater than their corresponding values into PB edges. The SET and STT in PB materials with pilot holes were lower than their corresponding ones without pilot holes. SET and STT values can be estimated using power equations including PB material core density and particle length and IB strength.
Downloads
Published
Issue
Section
License
The copyright of an article published in Wood and Fiber Science is transferred to the Society of Wood Science and Technology (for U. S. Government employees: to the extent transferable), effective if and when the article is accepted for publication. This transfer grants the Society of Wood Science and Technology permission to republish all or any part of the article in any form, e.g., reprints for sale, microfiche, proceedings, etc. However, the authors reserve the following as set forth in the Copyright Law:
1. All proprietary rights other than copyright, such as patent rights.
2. The right to grant or refuse permission to third parties to republish all or part of the article or translations thereof. In the case of whole articles, such third parties must obtain Society of Wood Science and Technology written permission as well. However, the Society may grant rights with respect to Journal issues as a whole.
3. The right to use all or part of this article in future works of their own, such as lectures, press releases, reviews, text books, or reprint books.