Abstract

Accurately predicting paint adhesion without the lengthy time required for typical exposure and evaluation is advantageous. Mechanical tests that use shear block, lap shear, or tensile specimens to measure paint adhesion result in large data variability, making it difficult to differentiate subtle changes in adhesive strength. The objective of this study was to decrease the variability of measured paint adhesion in fracture toughness tests. Preliminary and computer-aided experiments were conducted using uniform double-cantilever beam (UDCB) and shear block specimens. The coefficient of variation (COV) for the shear block tests was about 15%. The UDCB specimens cut from the same panels as the shear block specimens had a COV of 10%. Computer-aided tests of UDCB specimens gave a COV of less than 5%. Results show that using UDCB specimens with the aid of a computer is an excellent technique for determining paint adhesion to wood.

References

1.
Williams
,
R. S.
,
Winandy
,
J. E.
, and
Feist
,
W. C.
, “
Paint Adhesion to Weathered Wood
,”
Journal of Coatings Technology
 0361-8773, Vol.
59
, No.
749
,
1987
, pp.
43
-
49
.
2.
Williams
,
R. S.
,
Plantinga
,
P. L.
, and
Feist
,
W. C.
, “
Photodegradation of Wood Affects Paint Adhesion
,”
Forest Products Journal
 0015-7473, Vol.
40
, No.
1
,
01
1990
, pp.
45
-
49
.
3.
Mahlberg
,
R.
, “
Puualustan ja pinnoitteen välinen adheesio. Osa 1, Puualustan ominaisuuksien vaikutus [Adhesion of paints on wood substrate, Part 1. Effect of substrate factors]
,” Research paper, Tutkimuksia Forskningsprapporter Research Reports 476,
Technical research center of Finland
,
1987
.
4.
Ahola
P.
, “
Puualustan ja pinnoitteen valinen adheesio. Osa 2, Vanhenemisen vaikutus adheesioon. [Adhesion of paints on wood substrate. Part 2. The influence of exposure of the coatings]
,” Research paper. Tutkimuksia Forskningsprapporter Research Reports 520,
Technical Research Center of Finland
,
1988
.
5.
Strozier
J. K.
,
Ninow
,
K. J.
, and
De Vries
,
K. L.
, “
Tensile and Shear Stresses Induced in Adhesive Shear Test Specimens
,”
Journal of Adhesion Science Technology
, Vol.
1
, No.
3
,
1987
, pp.
209
-
225
.
6.
Okkonen
,
E. A.
and
River
,
B. H.
, “
Factors Affecting the Strength of Block-Shear Specimens
,”
Forest Products Journal
 0015-7473, Vol.
39
, No.
1
,
01
1989
, pp.
43
-
50
.
7.
Ebewele
,
R. O.
,
River
,
B. H.
, and
Koutsky
,
J. A.
, “
Wood Processing Variables and Adhesive Joint Performance
,”
Journal of Applied Polymer Science
 0021-8995, Vol.
32
,
1986
, pp.
2979
-
2988
.
8.
Scott
,
C. T.
,
River
,
B. H.
, and
Koutsky
,
J. A.
, “
Fracture Testing Wood Adhesives with Composite Cantilever Beams
,”
Journal of Testing and Evaluation
 0090-3973, Vol.
20
, No.
4
,
07
1992
.
9.
Forest Products Laboratory
,
Wood Handbook: Wood as an Engineering Material
, USDA Agriculture Handbook 72,
U.S. Government Printing Office
,
Washington, DC
,
1987
.
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