MANUAL ON THE PROPERTIES AND USES OF LESSER ... - ITTO

SawmillingDryingMachiningRefers to the ease of sawing or operation ofsawmill equipment and scheduling ofmaterials to produce optimum quantity andquality of sawn timber. Incidence ofsawmilling defects reduces the quantity andimpairs the quality of sawn timber product.LUS are grouped into 3 sawing classificationnamely: Class I - Easy to saw (average feedrate of 18 meters per minute with saw bladeperformance of 100 square meters and abovesurface area sawn); Class 11 - Moderate to saw(average feed rate of 14 square meter perminute with saw blade performance of 70 to100 square meters surface area sawn); ClassIII - Hard to saw (feed rate is less than 14meters per minute with saw blade performanceof not more than 70 meters surface area sawn.Refers to the process of removing moisturein wood to a desired level through applicationof Kiln Drying schedule to improve itsserviceability. Drying characteristics isinfluenced by density and anatomicalstructures. In general, high density and finetextured species are more difficult to dry thanthose with low density. Coarse texturedwoods are preferred for flooring panels, andother builders woodworks. LUS are groupedinto 4 drying classifications, namely: Class I- Easy to dry (with no difficulty of drying orno drying degrades if reasonable care is taken;Kiln Drying Schedule I); Class IT - Moderatelydifficult to dry (with slight tendency to check,warp or collapse; Kiln Drying Schedule 11);Class ill - Difficult to dry (susceptible to checkand warp; Kiln Drying Schedule Ill); ClassIV - Very difficult to dry (very slow to dryand easily checks; Kiln Drying Schedule IV).Refers to the process of cutting wood intodesired shapes and dimension using verysimple or complex woodworking equipmentsuch as moulder, routers, lathes and sanders.Machining improves surface quality andaesthetic value of wood.I7