Research Update
S1989
FORESTRY
IRST IN FORESTRY UPDATE
SERIES
This is the fi>st oesr. yresearch report
published in a new series entitled "Research
Update," inaugurated in 1989 by the Alabama
Agricultural Experiment Station (AAES), The
new series is meant to promote timely report-::
Ing of research results dealing with ai
specific commodity with distribution to all
producers of that particular commodity.
Forestry is a billion dollar industry In:
Alabama-one of the largest in the State, yet
the opportunities for growth in the in-State
manufacturing use of our forest resource
and export out of State and out of country of
raw forest materials are all excellent. This
report deals with forest products, the end use
of our timber resource. Future forestry up-
dates will deal with the production of timber
and wise management of forest!ands.
Todays highly competitive market
and increased dependence on the Southern
States for a higher percentage of fcrest
products make it doubly important 
that forest
product producers have available the latest
scientific information. Researchers in the
School of Forestry are striving to develop..
the necessary technology to help the State's
forest products industry grow, and this report
Is one method of del!vering the vital results.
of their research. Efforts will be made to
mamntan up-to-date mailing lists of each pro-
ducer group, so that all A:abama producers
will receive the appropriate report annually.
For more infermation about forest
products and forest productlon, please con
tact your county Extension Service office.
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Fire Retardant
Chemical Use
Increasing on Wood
Products
The use of wood treated with
fire retardants has consistently in-
creased annually to over 9.5 million
cubic feet in 1984. While these proc-
esses effectively inhibit 
combustion,
problems are being reported in the
use of fire retardant treated wood
for certain construction applications.
In some situations, over the
course of several months, the me-
chanical properties of fire retardant
treated wood has degraded, and the
wood hasa decayed appearance. The
magnitude of the problem is such
that the American Plywood Asso-
ciation has withdrawn published
strength reductions for fire retardant
treated plywood, and is referring all
inquiries to treaters and their sup-
pliers. This situation may reduce
the competitive position of the ma-
terial as compared to non-wood al-
ternatives.
While the changes in mechani-
cal properties have been docu-
mented, it is logical to assume that
the interactions among the fire re-
tardants, the chemical constituents
of wood, and the environment are
resulting in changes at chemical
levels of organization, which are re-
flected in the mechanical properties.
Research is underway to determine
the alterations in chemical structure
occurring in fire retardant treated
wood. The first step of this research
is to establish an understanding of
the induced chemical modifications.
This is essential to eliminate the nega-
tive effects produced by current re-
tardant formulations.
T.J. Elder
Mill Feasibility Study
Shows Need in
Northwest Alabama
In a recent study, forest prod-
ucts researchers confirmed the po-
tential profitability and impact on
the local economy of establishing a
mill in northwest Alabama to proc-
ess Alabama's under-utilized hard-
wood trees. The study evaluated the
A LABAMA AGRICULTURAL EXPERIMENT STATION AUBURN UNIVERSITY
LOWELL T. FROBISH, DIRECTOR, AUBURN UNIVERSITY, 
ALABAMA
economic potential of establishing
an oriented strandboard mill in Lynn
in Winston County.
Previous AAES research dem-
onstrated that some of the under-
utilized Southern hardwoods, like
sweetgum and yellow poplar, mixed
with Southern pines can be used for
oriented strandboard. (OSB) produc-
tion. Technically, OSB is composed
of compressed flakes or wafers
bonded with phenolic resin. These
flakes have a length-to-width ratio
of about 2 to 1, with the grain of the
flake running along the length of the
flake. The flakes in the surface lay-
ers are oriented along the panel
length, and the flakes in the core
layers are oriented across the panel
width. Hence, OSB has strength and
dimensional property characteristics
similar to those of plywood. In fact,
OSB serves as a replacement for
plywood in sheathing grade and
other structural applications. For
this reason, the full potential of the
S weetgum Flakes
Improve Structural
Panel
In Alabama, there are 21 mil-
lion acres of timberland and half are
in under-utilized low-grade hard-
wood forests. Clearly, the develop-
ment of technologies and techniques
for efficiently utilizing these low
grade hardwoods in manufacturing
value-added products, like wood-
based panels, is highly desirable.
A major concern in the devel-
opment and application of hard-
wood composites as building panel
materials is their serviceability or
lifetime performance, especially
under severe environments. The
structural application of hardwood
OSB3 market could be equated with
the predicted demand for structural
panels as a whole.
Georgia and Mississippi al-
ready have OSB3 mills with
sweetgum, yellow poplar, and other
soft Southern hardwoods mixed
with Southern pines as raw material
inputs, but Alabama, which has a
large supply of these trees, has no
OSB mill. The lack of specific infor-
mation on the sufficiency of the wood
raw material base for mill opera-
tion at a given location and the lack
of a definitive assessment on the
market potential for OSB products
made in Alabama are primary rea-
sons no OSB mill has been estab-
lished in the State. These issues were
addressed in a study to determine
the feasibility of establishing an OSB
manufacturing plant in Lynn. Three
production facility models were
examined and their financial feasi-
bility was analyzed.
Results of the study indicate
composite products could be im-
proved if quantitative and reliable
information concerning their long-
term performance was available.
Such information can be provided if
the time-dependent properties of the
load-carrying capacity of hardwood
composite materials under chang-
ing environments are fully under-
stood. A multi-phased research
program intended to explore these
problems was developed at the
School of Forestry in cooperation
with the Alabama Agricultural
Experiment Station and the South-
ern Forest Experiment Station, a
research division of the U.S. Depart-
ment of Agriculture's Forest Serv-
ice.
Results of studies already con-
ducted indicate that structural flake-
boards fabricated with sweetgum
that the projected value of the OSB
share of the national structural panel
market and the projected Southern
Region OSB3 values are substantial.
The outlook for Southern produc-
ers, including those in Alabama, is
positive. Projected trends in the
United States for the coming years
look good. There is certainly room
for more OSB products than are
currently being produced. It also
was established that there are ade-
quate wood supplies within a 65-
mile radius of Lynn to support an
OSB plant with annual capacity of
200 million square feet (3/8-inch
basis) or more. The financial analy-
sis showed that, considering a 12-
year planning horizon, such a plant
can generate positive internal rates
of return, positive cash flow, and a
reasonable payback period. Clearly,
the results of the study indicate that
conditions in Lynn, Winston County,
Alabama, are favorable for an OSB
plant.
H. F. Carino
flakes showed much better long-term
performance than those made of
white oaks under concentrated load
and changing environments. In-
creasing the resin content in the
board from 5 to 7 percent signifi-
cantly improved the long-term per-
formance of boards exposed to
changing environments.
R. C. Tang
Composite Wood
I-Beams For Building
Construction
The forest resource that pro-
vides solid sawn timber products
traditionally employed for light and
medium frame construction in this
country is changing. Large tree size
is diminishing, and sawlog quality
and quantity are slowly declining.
Consequently, the larger and longer
sections needed for floor and roof
framing, such as 2-inch x 10-inch
and 2-inch x 12-inch with over 20
foot lengths in structural grades No.
2 and better, are becoming scarce
and more expensive.
More complete utilization of
Alabama's total forest resource is a
goalof forestry research. The use of
selected hardwoods, which are of-
ten under-utilized offset a shortage
of longer and larger solid sawn
boards. Auburn research has devel-
oped composite structural I-beams
to replace the solid sawn wood joists.
Results indicated that such compos-
ite I-beams, fabricated with finger-
jointed small cross sectionsand short
stocks of Southern pine lumber as
flanges and composite panels made
of under-utilized hardwood as web
Taiwan Potentially
Profitable Market For
Alabama's Hardwoods
In 1987, approximately $1.2
billion worth of furniture from Tai-
wan was imported by the United
States. This amount is about 32.3
percent of the total value ($3,648
million) of furniture imported into
the nation from all other countries
that year.
Taiwan is a small island and
has little hardwood resources util-
izable for furniture making. In 1987,
Taiwan imported 140 million cubic
feet of logs (85 percent hardwood
and 15 percent softwood valued at
$445 million), 38 million cubic feet of
materials, are suitable for structural
applications in building construc-
tion. Their engineering perform-
ances, such as maximum load and
deflection criteria, are equivalent to,
and better in some cases, than those
of traditionally used solid lumber.
It is estimated that the total
replacement of solid sawn wood
joists (over 16 feet in length) with the
developed composite I-beams in the
United States could save approxi-
mately 220 million cubic feet of high
quality structural lumber annually.
In addition, 80 million cubic feet (3/
8-inchbasis) ofcompositehardwood
panels will be needed annually for
the I-beam fabrication. Thus, a suc-
cessful development of composite I-
beam structures may provide the
much needed economic advantage
for Alabama, as well as for the South-
ern Region, in the production of
building construction structures.
R. C. Tang
lumber (80 percent hardwood and
20 percent softwood valued at $320
million), and 1.4 million metric tons
of pulpwood and chips (95 percent
hardwood and 5 percent softwood
valued at $55 million).
Taiwan is a potentially profit-
able market for Alabama hardwood
products and, cognizant of this ex-
cellent prospect, officials of the State
of Alabama organized two forest
products trade mission groups
comprised of high ranking govern-
ment officials and representatives of
the forest products industry and the
School of Forestry at Auburn. These
groups visited Taiwan during the
last 3 years to promote and develop
sales and trade of Alabama's forest
products, particularly hardwoods.
In return, two groups of forest in-
dustry people from Taiwan visited
Alabama during the last 2 years.
These contacts have been judged
fruitful considering the significant
increase in the export sale of Ala-
bama hardwood products to that
country. This trend is expected to
continue.
R. C. Tang
Narrow Spaced Pines
Provide High Quality
Lumber
Recent tests indicate that
closely spaced, or "plantation," pines
may be of higher quality than previ-
ously believed. Test results show
that a 27-year-old slash pine plan-
tation with 6-foot x 6-foot spacing
can provide high quality lumber that
meets the Southern Pine Inspection
Bureau requirements for visual
grades.
Pine plantations in the South
have been established primarily with
genetically superior seedlings or
seeds to improve the quality of trees
(bole taper, straightness, branching,
and disease resistance) and to maxi-
mize the growth per acre per dollar
investment. The original spacings
in these plantations vary from 6 x 6
to 10 x 10 feet, with several combina-
tionsbetween. In general, thinnings
are done on plantations with close
spacings. Often, understory vegeta-
tion control is performed as part of
the silvicultural management of
plantations. It has been observed
that such intensive management
yields impressive growth rates for
the first 8 to 10 years and relatively
good growth rates (4 to 5 rings per
inch) for the next 5 to 6 years. The
end use of the timber product of
such plantations has been mostly for
pulp.
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The diameter breast height
(dbh) of fast-grown plantation
Southern pine timber has been noted
to reach 11.2 inches in 5 years and
14.3 inches in 20 years. Not surpris-
ingly, some of these trees have been
used for producing lumber. Studies
have shown, however, that wood
from certain plantations of Southern
pine timber has lower density, me-
chanical properties, and visual qual-
ity than that of timber grown natu-
rally. These deficiencies are attrib-
uted to the presence of large amounts
of juvenile wood, with volumes as
high as 90 percent in 15-year-old
trees and 60 percent in 20-year-old
trees.
Juvenile wood in Southern
pines has lower specific gravity,
shorter fibers, larger fiber angles,
thinner cell walls, larger lumen di-
ameter, and lower percentage of
summerwood than mature wood.
Thus, lumber with juvenile wood
has generally low strength and stiff-
ness and large longitudinal shrink-
age. It has been reported, for in-
stance, that lumber from 20-year-
old plantations of loblolly and slash
pines in Texas had low strength and
that a large percentage of the boards
produced could not meet the
strength and stiffness required by
the assigned visual grader.
However, the results of a study
at Auburn's Forest Products Labo-
ratory on lumber from a 27-year-old
slash pine plantation are encourag-
ing. About 43.4 percent, 48.7 per-
cent, and 7.9 percent of the boards
produced were No. 1, No. 2, and No.
3 grades, respectively. Clearly, there
is an exceptionally high grade distri-
bution of boards. It was observed
that the boards tested have relatively
high density and few small knots,
which could be attributed to the close
original spacing of 6 feet x 6 feet and
unthinned condition of the planta-
tion. This observation, 
however,
needs to be verified with additional
studies involving other spacings and
ages.
E. J. Biblis
Structural Flakeboards Need Added Quality
Presently, commercial struc-
tural flakeboard panels in the South
are produced from mixtures of
Southern pines and sweetgum in 7/
16-inch thickness and densities of 40
to 45 pounds per cubic foot with ap-
proximately 3-5 percent liquid phe-
nolic resin. These panels are primar-
ily used as sheathing in housing and
are significantly heavier than South-
ern pine plywood and Aspen wafer-
board of equal thickness. 
However,
these are manufactured to meet the
American Plywood Association's
Performance Standards for struc-
tural panels.
Other uses for Southern struc-
tural flakeboards are currently being
investigated and there are compel-
ling reasons for doing this. One is to
improve the utilization of timber
resources which are diminishing in
quantity and size. Another is to
keep the present and future mills
producing panels with added-value
at capacity levels which are consid-
ered profitable. Extending the uses
of the structural flakeboard panels
means the development of panels
with higher strength, dimensional
stability, and durability for exterior
uses. Specifically, the following
panel properties need to be im-
proved: thickness swelling at edges,
edge checking, and surface rough-
ness after the panels are subjected to
humidity variations.
In a study at the Forest Prod-
ucts Laboratory, phenolic resin
impregnated paper was overlaid
and bonded successfully to struc-
tural flakeboard panels manufac-
tured from mixtures of Southern
pines and hardwoods. Results indi-
cate that the bond between the 
pa-
per overlay and the board is stronger
than the internal bond strength of
the flakeboard substrate. The resin
impregnated paper when overlaid
on one surface of the flakeboard
substrate can provide a structural
improvement of 10-15 percent for
various mechanical properties.
Results of the study also indi-
cate that, when the overlaid surface
is exposed to continuous wetting
while the back surface is protected
from wetting, thickness swelling and
checking of the drip edge can be con-
trolled effectively through proper
priming, painting, and edge-sealing.
However, under the same exposed
conditions, the overlaid surface
becomes non-smooth with undesir-
able visual effects known as "tele-
graphings" which are protrusions of
swollen flakes through the overlayer.
Unfortunately, in the Auburn tests
telegraphing could not be eliminated
or controlled with the application of
primers or paints.
E. J. Biblis
SELECT: A New
Approach To Lumber
Allocation
SELECT, a computer program
being developed for use on personal
computers through 
AAES research,
may help hardwood furniture manu-
facturers reduce production cost by
25-30 percent. The savings would
come primarily from better lumber
allocation, though SELECT can be
--
used for lumber procurement and to
evaluate the efficiency of sorting
lumber according to grades and
sizes.
Lumber cost constitutes about
40-60 percent of the total cost in
producing hardwood furni ture, and
incorrect lumber allocation is a ma-
jor reason for the relatively high cost.
Many rough mill production man-
agers have only their intuition and
empirical methods for solving the
perennial problem of finding the best
(or least-cost) mix of lumber in in-
ventory to satisfy a given cutting
bill. The problem appears to be
simple, but it becomes complex
because, on one hand, blanks or
dimension parts can be manufac-
tured from different types (i.e., the
combination of species, grades, and
sizes) of lumber. On the other hand,
the yields of blanks and the associ-
ated costs (unit and conversion costs)
vary with the type of lumber used.
This is further complicated by the
possibility of cutting different mixes
of blanks from a given board.
Yield tables, nomograns, and a
variety of computer programs em-
bodying operations research (OR)
techniques, particularly linear pro-
gramming (LP), have been devel-
oped to solve the problem. How-
ever, these tools have several major
flaws which limit their practical
application. For one thing, these
tools differentiate lumber in a given
species group in terms of grade only.
Lumber size is not considered a de-
cision variable, making the alloca-
tion process as devised insensitive
to cost reducing opportunities that
result from differences in blank yield.
The existing tools cannot be used
across species groups because speci-
fications in the grading rules ap-
plied to the different species groups
differ. Each existing tool is species
specific, and moreover, these tools
do not indicate output of cutting
patterns for each grade/type of
lumber to be used. It is important
that the cutting pattern for each board
in terms of sizes and number of
blanks be known to the saw operator
in order to maintain an "optimum"
mix of lumber input.
To overcome the limidtations of
currently used tools, forest products
research at the AAES developed a
heuristic solution procedure called
SELECT which handles the lumber
allocation problem in three stages.
The first stage involves the "conver-
sion" of the lumber into defect-free
boards or clear-face cuttings using
an integer non-linear programming
model to simulate the grading of
hardwood lumber by NHLA rules.
In the second stage, the defect-
free boards are cut into blanks and
the cutting patterns, or instructions
on how the cutting should be 
done,
are generated. The crosscutting and
ripping operations are simulated via
an integer programming model
(called LC/SP) with a double knap-
sack formulation.
In the third stage, various types
of available lumber are allocated into
the blanks or parts demanded, given
a set of cutting patterns. A linear
programming model (called LAP)
was developed for this purpose. The
following steps define the required
operations and interfaces between
the models in the algorithm SELECT:
(1) For each type of lumber
available, solve the conversion
model to generate clearface cuttings.
(2) Generate an initial set of
cutting patterns or take those cur-
rently used by the firm.
(3) Solve the "reduced" ver-
sion of LAP, that is, without the
lumber supply constraints. If first
iteration, go to step 5. Otherwise, go
to step 4.
(4) Calculate the cost improve-
ment generated for the two immedi-
ately preceding iterations. If the total
improvement is less than the aspira-
tion level set, go to step 7. Other-
wise, go to step 5.
(5) Solve the LC/SP. If no cut-
ting patterns can be generated that
can improve (i.e., the solution isnon-
positive) on the current set of cutting
patterns, go to step 7. Otherwise, go
to step 6.
(6) Append the set of newly
generated cutting patterns to the
current set and go to step 3.
(7) Solve the "full" version of
LAP, that is, with the lumber supply
constraints and stop. The current
solution is the best under the present
constraints.
The algorithm was used in a
case study involving a hardwood
cabinet manufacturing operation. It
indicated that through a better lum-
ber allocation process it is possible
to realize lumber input cost savings
of about 26 percent which could
accrue from a 24 percent increase in
blank recovery or an equivalent
reduction in lumber input volume
of about 32 percent.
H. F. Carino
Foreign Research
Benefits
U. S. Forest Industry
A team of forestry researchers,
including a member of the School of
Forestry, recently reported in the
Journal of Forestry on the benefits
that research conducted in foreign
countries has provided to forestry
research in the United States. The
Auburn study explored two impor-
tant questions: (1) does the United
States benefit from research con-
ducted in other countries; and (2) to
what extent should the United States
I
encourage and facilitate increased
interaction between our researchers
and those of foreign forestry research
institutions?
Science and technology indi-
cators show that foreign countries
have been increasing their invest-
ment in science and technology while
our investment has been increasing
at a slower rate, if at all. From 1975
to 1985, U.S. non-defense research
and development expenditures in-
creased from about 1.7 percent to 1.8
percent of GNP, while in Japan the
change was from 1.9 percent to 2.8
percent and in the Federal Republic
of Germany their commitment went
from 2.1 percent to 2.6 percent. Be-
tween 1960 and 1984, the percentage
of U. S. patents granted to foreign
inventors jumped from 16 percent to
43 percent. U.S. forestry research
constituted 23 percent of global re-
search effort in 1970 and dropped to
19 percent in 1981. Thus, our re-
search scientists need to be aware of
foreign research as never before.
Based on the two case studies
analyzed, one research project that
led to the structural particleboard
EDITOR'S NOTE
Mention of company or trade
names does not indicate endorsement by
the Alabama Agricultural Experiment
Station or Auburn University of one
brand over another. Any mention of
non-label uses or application other than
labeled rates of pesticides or other chemi-
cals does not constitute a recommenda-
tion. Such use in research is simply part
of the scientific investigation necessary
to fully evaluate materials and treat-
ments.
Information contained herein is
available to all persons without regard to
race, color, sex, or national origin.
September 1989 4M
industry and the other study of con-
tainerized forest tree seedlings, the
answer to the first question is yes.
The United States has definitely
gained significantly from foreign re-
search in structural particleboard
and containerized forest tree seed-
lings. Indications of gain also exist
in other areas of forest and forest-
industry activity, such as acid rain,
pest management, and forest har-
vesting.
The answer to the second ques-
tion is less clear. From the evidence
at hand for research and for science
in general, it would seem that fur-
ther efforts to promote interaction of
scientists are justified. That is, more
should be done to encourage, pro-
mote, and facilitate increased inter-
action between the United States and
foreign forestry research systems.
The U.S. research community is
increasingly dependent on the work
of foreign researchers. Whether
additional formal programs and
policy support are needed and justi-
fied in this area cannot be answered
without further and more complete
analysis by the U.S. forestry com-
munity.
John Haygreen
Alabama Agricultural Experiment Station
Auburn University
Auburn University, Alabama 36849-0520
SUPPORT
FORESTRY
RESEARCH
Funds appropriated by
the Alabama legislature 
pro-
vide the major financial sup-
port for forestry research in the
Alabama Agricultural Experi-
ment Station. McIntire-Sten-
nis funds from the U.S. govern-
ment also represent an impor-
tant funding source. Since these
funds are limited, many areas
of research would go unsup-
ported except for financial
support from various granting
agencies, commodity 
groups,
and private companies.
The AAES and School of
Forestry wish to thank these
groups who have provided
grant funds or in many cases
labor and land resources to
support research.
NON-PROFIT ORG.
POSTAGE & FEES PAID
PERMIT No. 9
AUBURN, ALA.
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