Veneer Cuts
Plain Sliced
Plain slicing a log occurs when a log is only turned a few inches at a time when slicing it, versus a constant turn and peeling method used for Rotary Cut veneer. Plain Sliced veneer produces a cathedral grain pattern, similar to the pattern produced when plain sawn lumber is produced. Plain Sliced veneer is cut along the growth rings, producing the highest yield of any “slicing” method.
Rotary
Rotary is the process of peeling the entire long. Turning the log, while shaving the veneer as it turns produces Rotary Cut veneer. This process is the only cutting method that is capable of producing whole piece face veneers. Rotary cut will yield veneer with a broad grain pattern with no plain sliced or quartered appearance. Rotary cut veneers are used in the majority of panels produced in North America. This process yields the most veneer per log and is usually less expensive than sliced veneer.
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Exotic Plywood Grade Rules
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Indonesian/Malaysian Grade Rules
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FD Grade
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Free-Of-Defect, very
similar characteristics to an ANSI/HPVA “A” Grade.
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BB Grade
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Smooth, tight cut,
full length veneer. Natural characteristics of the wood such as pin knots, sound
burls, color streaks and spots are allowed. Dead knots, stain and mineral streaks,
decay, open splits, rough cut, torn grain, symmetrical patches are not allowed.
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CC Grade
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Natural characteristics
of the wood are allowed. However, in comparison to the “BB Grade” the following
characteristics ARE permitted: Color, dead knots and rough cut (if well puttied),
and hairline splits (max. 6”).
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OVL Grade
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Overlay and Better
Grade. In addition to BB and CC grade, OVL may contain dead knots and knot holes
(if well puttied), stain and mineral streak, hairline splits (max. 12”), rough cut
and torn grain.
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Industrial
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Allows open defects
such as splits and gaps at the veneer joint as well as all the natural characteristics
of the wood specie.
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Note: The BB and CC grades are usually combined
and marketed as a BB/CC panel.
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Chinese Grade Rules
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B/C or B/2 Grade
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Fairly uniform in
color with slight contrasts allowed. Small conspicuous burls and pin knots allowed
with a minimum number of scattered sound or repaired knots. Both faces are typically
sanded smooth. The “C” back grade is typically more on the C minus to D plus grade
or compatible to a #1 and #2 mix back grade on ANSI/HPVA standards.
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C/D or C/2 Grade
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A larger color contrast
is allowed. There are a unlimited number of conspicuous burls and pin knots and
greater quantity of scattered sound and repaired knots allowed. “Blended Repaired”
is allowed whereby splits in the veneer will be repaired with color matched putty.
The “D” back grade is typically more on the D minus grade or compatible to a #2
and #3 mix back grade on ANSI/HPVA standards.
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D/E or D/3 Grade
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All defects not permitted
by C grade will generally be allowed on D grade. More sound and dark pin knots,
repaired knot holes, longer putty repaired veneer splits will be allowed, but the
number of knot holes is the major determining factor. The “E” back grade borders
in grade and similarity to the #4 or reject back grade on ANSI/HPVA standards.
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Note: The majority of these panels are laid up on
a Chinese Poplar core. IT IS VERY IMPORTANT TO UNDERSTAND THE APPLICATION OF THE
PANEL. B Grade: often used for upper-end
cabinetry, architectural millwork, and furniture. C Grade: used primarily on paint grade type applications, in lower-end casework,
and for cabinet interiors in upper-end cabinetry. D Grade: used for non-visible cabinet parts.
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Russian (Baltic) Birch Grade Rules
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B Grade
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One piece sanded
face with even color. No patches, voids or mineral streaks allowed.
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BB Grade
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One piece sanded
face with generally even color. Slight pin knots and mineral streaks allowed. Open
knots and defects are cut out and replaced with oval patches.
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CP Grade
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This is a fall down
from BB with more patches on the face that may not always be matched for color.
Splits less that 0.5 mm are allowed.
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C Grade
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Un-sanded face that
allows patches, open knots and veneer splits.
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Note: Russian Birch panels are a consistent specie
throughout the panel (core and face and back veneer).
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Core Descriptions
Combination Core
There are two types of Combination Core construction. The first type consists of a center veneer core and a crossband veneer on both sides of the center with a layer of MDF, particleboard, or hardboard under the face and back veneer. The second type consists of an oriented strand board or wafer board center with a veneer crossband on both sides, under the face and back veneer.
Lumber Core
Lumber edge glued into a solid slab is considered Lumber Core. Lumber Core plywood is most often found in the construction of import panels, usually only 18mm thickness panels. Lumber Core plywood consists of a face & back veneer, then a layer of crossband veneer, with the edge glued lumber in the center.
MDF Core
Medium Density Fiberboard Core has the most uniform thickness and consistency of any panel core. The face and back veneer are glued directly to the MDF Core without the need for a crossband veneer.
Particleboard Core
Particleboard Core panels are constructed similar to MDF Core panels, with the face & back veneers glued directly to the core. Particleboard Core lays flat like MDF, but does not have the screw-hold strength of other cores.
Veneer Core
Veneer Core plywood consists of a center veneer and crossband veneers alternately layered on both sides of the center to the desired thickness producing an odd number of veneers for the core. The weight-bearing strength of Veneer Core plywood is excellent along with its bending strength and screw-hold ability.
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