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Pinus taeda |
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Family: L. Pinaceae |
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Loblolly Pine |
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The genus Pinus is composed of about
100 species native to temperate and tropical regions of the world. Wood of pine
can be separated microscopically into the white, red and yellow pine groups.
The word pinus
is the classical Latin name. The word taeda is the ancient name of
resinous pines. Loblolly pine is one of the southern pines.
Other Common
Names:
Bastard pine, black pine, black slash pine, bog pine, buckskin pine, bull pine,
Carolina pine, cornstalk pine, foxtail pine, frankincense pine, heart pine,
Indian pine, kienbaum, lobby pine, loblolly pine, longleaf pine, longschap
pine, longschat pine, longshucks, longshucks pine, longstraw pine, maiden pine,
meadow pine, North Carolina pine, old pine, oldfield pine, pin a l'encens, pin
taeda, pinho-teda, pino de incienso, pino dell'incenso, prop pine, Rosemary
pine, sap pine, shortleaf pine, shortstraw pine, slash black pine, slash pine,
soderns gul-tall, southern pine, southern yellow pine, spruce pine, swamp pine,
sydstaternas gul-tall, taeda pine, taeda-pijn, torch pine, Virginia pine,
Virginia sap pine, yellow pine.
Distribution: Loblolly pine is native
to the Coastal Plain and Piedmont from southern New Jersey and Delaware south
to central Florida and west to eastern Texas, and in the Mississippi Valley to
extreme southeastern Oklahoma, central Arkansas and southern Tennessee.
The Tree: Loblolly pine trees
reach heights of 150 feet, with diameters of 5 feet. A record was reported to
be 163 feet tall with a diameter of 56 inches.
General Wood
Characteristics:
The sapwood of loblolly pine is a yellowish white, while the heartwood is a
reddish brown. The sapwood is usually wide in second growth stands. Heartwood
begins to form when the tree is about 20 years old. In old, slow-growth trees,
sapwood may be only 1 to 2 inches in width. The wood of loblolly pine is very
heavy and strong, very stiff, hard and moderately high in shock resistance. It
also has a straight grain, medium texture and is difficult to work with hand
tools. It ranks high in nail holding capacity, but there may be difficulty in
gluing. All the southern pines have moderately large shrinkage but are stable
when properly seasoned. The heartwood is rated as moderate to low in resistance
to decay. The sapwood is more easily impregnated with preservatives.
Mechanical
Properties (2-inch standard)
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Compression |
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Specific gravity |
MOE x106 lbf/in2 |
MOR lbf/in2 |
Parallel lbf/in2 |
Perpendicular lbf/in2 |
WMLa in-lbf/in3 |
Hardness lbf |
Shear lbf/in2 |
Green |
0.47 |
1.40 |
7300 |
3510 |
390 |
8.2 |
450 |
860 |
Dry |
0.54 |
1.79 |
12800 |
7130 |
790 |
10.4 |
690 |
1390 |
aWML = Work to maximum load.
Reference (56). |
Drying and
Shrinkage
Type of shrinkage |
Percentage of
shrinkage |
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0% MC |
6% MC |
20% MC |
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Tangential |
7.4 |
5.9 |
2.5 |
Radial |
4.8 |
3.8 |
1.5 |
Volumetric |
12.3 |
9.8 |
4.1 |
References: (56, 192). |
Kiln Drying
Schedulesa
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Conventional
temperature/moisture content-controlled schedulesa |
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4/4,
5/4 |
6/4
stock |
8/4 |
10/4 |
12/4 |
British
schedule |
Standard |
T13-C6 |
T12-C5 |
T12-C5 |
T10-C4 |
T10-C4 |
L |
Highest Quality |
279 |
279 |
279 |
T10-C4 |
T10-C4 |
NA |
aReference
(28, 92,185). |
Conventional
temperature/time-controlled schedulesa |
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Lower
grades |
Upper
grades |
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4/4,
5/4 stock |
6/4
stock |
8/4
stock |
4/4,
5/4 stock |
6/4
stock |
8/4
stock |
12/4,
16/4 stock |
Standard |
281 |
NA |
282 |
281 |
NA |
282 |
284 |
aReferences
(28, 92, 185). |
High temperaturea |
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4/4,
5/4 stock |
6/4
stock |
8/4
stock |
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Standard |
401/402 |
NA |
NA |
2 by 4's 403 2 by 10's 403 4 by 4's 404 |
aReferences
(28, 92 185). |
Working
Properties:
is difficult to work with hand tools. It ranks high in nail holding capacity,
but there may be difficulty in gluing.
Durability: The heartwood is rated
as moderate to low in resistance to decay.
Preservation: The sapwood is more
easily impregnated with preservatives.
Uses: The denser and higher
strength southern pine is used extensively in construction of factories,
warehouses, bridges, trestles, and docks in the form of stringers, and for roof
trusses, beams, posts, joists, and piles. Lumber of lower density and strength
finds many uses for building material, such as interior finish, sheathing,
subflooring, and joists and for boxes, pallets, and crates. Southern pine is
also used also for tight and slack cooperage. When used for railroad crossties,
piles, poles and mine timbers, it is usually treated with preservatives. The
manufacture of structural grade plywood from southern pine has become a major
wood-using industry.
Toxicity: In general, working
with pine wood may cause dermatitis, allergic bronchial asthma or rhinitis in
some individuals (6,10&15).
Additional
Reading and References Cited (in parentheses)
1. Baker, J. B.
and Langdon, O. G. Pinus taeda L. Loblolly Pine. in: Burns, R. M. and Honkala, B. H.,
tech. coords. Silvics of North America. Volume 1, Conifers. Washington, DC:
USDA Forest Service; 1990; pp. 497-512.
2. Boone, R. S.;
Kozlik, C. J.; Bois, P. J., and Wengert, E. M. Dry kiln schedules for
commercial woods - temperate and tropical. Madison, WI: USDA Forest Service,
FPL-GTR-57; 1988.
3. Dallimore,
W.; Jackson, A. B., and Harrison, S. G. A handbook of Coniferae and
Ginkgoaceae. London, UK: Edward Arnold Ltd.; 1966.
4. Elias, T. S.
The complete trees of North America, field guide and natural history. New York,
NY: van Nostrand Reinhold Co.; 1980.
5. Gaby, L. I.
The southern pines, an American wood. Washington, DC, USA: USDA Forest Service,
FS-256; 1985.
6. Hausen, B. M.
Woods injurious to human health. A manual. New York, NY: Walter de Gruyter;
1981.
7. Henderson, F.
Y. A handbook of softwoods. London: HMSO; 1977.
8. Koch, P.
Utilization of the southern pines. I. The raw material. II. Processing.
Washington, DC, USA.: USDA Forest Service, Ag. Handbook No. 420.; 1972.
9. Little, jr.
E. L. Checklist of United States trees (native and naturalized). Washington,
DC: USGPO, USDA Forest Service, Ag. Handbook No. 541; 1979.
10. Mitchell, J.
and Rook, A. Botanical dermatology: plants and plant products injurious to the
skin. Vancouver, BC: Greenglass Ltd.; 1979.
11. Simpson, W.
T. Dry kiln operator's manual. Madison, WI: USDA Forest Service, FPL Ag.
Handbook No. 188; 1991.
12. Sternitzke,
H. S. and Nelson, T. C. The southern pines of the United States. Economic
Botany. 1970; 24(2):142-150.
13. Summitt, R.
and Sliker, A. CRC handbook of materials science. Vol. 4. Boca Raton, FL: CRC
Press, Inc.; 1980.
14. USDA. Wood
handbook: wood as an engineering material. Madison, WI: USDA Forest Service,
FPL Ag. Handbook No. 72 1974.
15. Woods, B.
and Calnan, C. D. Toxic woods. British Journal of Dermatology. 1976; 95(13):1-