Veneer grades, recoveries, and values from 5-year-old eucalypt clones

Abstract

& Context Processing young, small eucalypt logs into veneer is a burgeoning industry across southern China. However, plantations supplying these logs were mostly established for pulpwood; little information is available on variation and selection among commercial eucalypt clones/varieties in regards to suitability for veneer production. & Methods Tree growth and log form were assessed on 11 eucalypt clones from a 5-year-old trial in southern China. Logs from these were rotary peeled for veneer; recovery percentages plus a range of quality and value traits were assessed on the outturn. & Results Tree volumes, green veneer recovery ratios (%), veneer quality grades, log value, and value m −3 varied significantly among both clones and log positions up the stem. The clone with the best veneer recovery ratio (50.5 %) provided nearly twice that of the poorest clone (28.4 %). Average veneer value log −1 by clone ranged from RMB 6.7 (US$1) up to RMB 15.1 (US$2) and average value m −3 by clone ranged from 589 RMBm −3 (US$88) up to 925 RMBm −3 (US$139). Overall, sweep was the key factor influencing veneer recovery ratio and value. Knots, especially dead knots, holes and splitting were major factors influencing veneer quality grade. Middle and upper logs had significantly higher veneer recoveries, grades, and values m −3 than the lower logs. & Conclusions Excellent potential exists for selecting among eucalypt clones, and even among log positions within trees, for optimizing veneer production.

Veneer Recovery Analysis of Plantation Eucalypt Species Using Spindleless Lathe Technology

“…These values are quite low compared with this study, which could possibly be attributed to the application of traditional technologies, which produce larger diameter peeler cores and failed peeling due to spindle grip problems (e.g., core splitting). In a study using spindleless lathe technology in China, Luo et al (2013) reported an average green veneer recovery (defined similarly to gross veneer recovery in this study) of 44% (ranging from 28% to 51%) for 11 different five-year-old eucalypt clones. The comparatively low green veneer recovery observed is likely attributable to a lower average small-end diameter of the billets (112 mm).…”

“…According to Arnold et al (2013), there are more than 5,000 small-scale veneer mills in China dedicated to the processing of young, smalldiameter eucalypt logs. However, there are few publications providing detailed information on the veneer quality and recovery from spindleless lathe technology (e.g., Luo et al 2013). To date, there are no published recovery data (including product grade recovery) for the use of this technology in the processing of Australia's plantation resources, which involve different species and climates from those in Asian countries.…”

Rapid Detection of Knot Defects on Wood Surface by Near Infrared Spectroscopy Coupled with Partial Least Squares Discriminant Analysis

“…These plantation trees present many advantages, such as fast growth and straight stem form, which make them suitable for plywood production. Production of plywood in China has increased rapidly over the last 20 years from 2.1 million m 3 in 1993 to more than 50 million m 3 in 2010 (Luo et al 2013). Such high productivity makes it necessary to evaluate the quality of veneer.…”

Variation in Rotary Veneer Recovery from Australian Plantation Eucalyptus globulus and Eucalyptus nitens

“…Different veneer grading methods also help explain the variation. Luo et al (2013) reported an average green veneer recovery (defined similarly to gross veneer recovery in this study) of 44% (ranging from 28% to 51%) for 11 different five-year-old eucalypt clones in China. While adopting spindleless lathe technology, similar to this study, the comparatively low green veneer recovery observed is likely attributable to a lower average small-end diameter of the billets (112 mm).…”