The main reasons for the rejection of pieces center on bark pocket
length, knot size, and resin pockets length, at 20.
Defect/Board # 1 #2 #3 #4 #5 #6 Mineral streak x Fleck x Coloration x x x Sound knot Pin knot x Black knot Bark pocket
Curl White speck x Decay Blue stain x Worm hole x x Cluster of worm holes x Wane x x Split x Shake Through shake x Hit and miss x Mechanical burn x Defect/Board #7 #8 #9 #10 #11 Mineral streak x Fleck x x x x Coloration Sound knot x Pin knot Black knot x Bark pocket
x x Curl x x White speck Decay x Blue stain Worm hole x Cluster of worm holes Wane x Split x x Shake x Through shake Hit and miss Mechanical burn Table 3.
Overall, bark pocket
is the most frequently occurring defect.
Nearly all veneers are subject to some minor problems, such as: pin knots, gum knots, cross bars (or deviation in the grain), bark pockets
, or worm tracks.
In addition to "standard" maple, Wellborn offers "character' maple," a look that has unique characteristics brought out by randomly occurring, variously sized knots, pin holes, worm holes and tracks, gum and bark pockets
, sugar tracks, heartwood and mineral streaks.
The study featured 25 moulded Lumber samples using five different types of character wood, including: large and small bark pockets
, grain variation, spike knots and a figure known as punky knots.
normally appear as long, narrow defects in pallet stringers (Fig.
In this study "character" was defined as the presence of any feature that could be distinguished from clear wood, including grain variations, knots, bark pockets
and heart stain patterns.
This will involve the use of material using more "natural" characteristics such as mineral streaks and stains, bark pockets
, bird pecks, grain swirls, pin knots, knot clusters, sap pockets and small worm holes which are currently classified as defects.
Alaska birch lumber is often characterized by small knots and other character defects (including bark pockets
, bird pecks, and worm holes) that can reduce its value when graded according to conventional (NHLA) hardwood lumber grading rules.
Splits, wane, shake, holes, decay, unsound knots, bark pockets
, and mechanical defects were all considered to be unsound.
The frequency of intergrown knots, partially intergrown knots, loose knots, and bark pockets
was significantly lower in boards from pruned logs than in boards from unpruned logs.