Istraživanje uticaja prečnika i kvaliteta bukove oblovine na količinu glavnih i sporednih proizvoda u pilanskoj preradi drveta

Abstract

Tehnološki proces pilanske prerade bukve je složen, troškovi su često veći, a iskorišćenje slabije u odnosu na druge vrste drveta. Razlog za to je što su bukovi trupci nepravilne forme i sadrže različite greške građe drveta. Jedna od karakterističnih grešaka je lažno srce, jer sortimenti izrađeni od takvog drveta imaju nižu vrednost i ograničenu primenu u finalnim proizvodima. Predmet istraživanja je uticaj prečnika bukovih trupaca, njihovog kvaliteta i ciljanog kvaliteta rezane građe na iskorišćenje i sortimentnu strukturu u sirovom tehnološkom postupku pilanskih prerade. Istraživanje je obavljeno na 90 trupaca koji su podeljeni na tri kvalitetne klase (prema standardu JUS D.B4.028) i tri debljinske grupe. Debljinske grupe su bile: 30-34 cm (debljinski podrazred IIIa), 35-39 cm (debljinski podrazred IIIb) i 40-49 cm (IV debljinski razred). Dužina trupaca bila je 4 m. Izrađivana je okrajčena i neokrajčena rezana građa, srčanica i sitni sortimenti (četvrtače, frize i metlarka). Svi navedeni glavni sortimenti, kao i sporedni (otpaci) su premereni i ustanovljeno je njihovo učešće u odnosu na trupac. Na osnovu dobijenih podataka, prikazani su kvantitativno iskorišćenje sirovine, sortimentna struktura, vrednosni pokazatelji i dobit. Prilikom prerade oblovine je variran i ciljani kvalitet okrajčene rezane građe. Iz trupaca III debljinskog razreda je izrađivana okrajčena građa za egipatsko, a iz trupaca IV razreda za italijansko tržište. Svi ostali sortimenti su izrađivani prema kriterijumima domaćeg tržišta...

The processing of beech round-wood is very complex and challenging, usually considering higher costs and lower yields in comparison to the processing of other wood species. The beech logs have irregular shape and comprise of different forms of faults in wood structure. One of the characteristic faults in beech wood is the appearance of false heartwood, downgrading the value of the sawmill products with such features and limiting their application. The goal of this dissertation was to evaluate the influence of diameter of beech logs, its quality and the aimed quality of sawn timber, on the yield and the structure of the end products in a sawmill technological process. The object of the research included 90 logs, divided in tree quality classes according to the standard JUS D.B4.028. In addition, tree thickness classes were chosen: 30-34 cm (thickness subclass IIIa), 35-39 cm (thickness subclass IIIb) and 40-49 cm (thickness subclass IV). Both edged and non-edged sawn timber were produced, together with red heart boards and small dimension elements. Those main products, as well as by-products (waste), were measured and their ratio in the log was determined. The data were used to calculate the quantitative yield of the raw material, products structure, quality characteristics and the end products value. The target quality of edged sawn timber was varied during the processing of round-wood. The sawn timber corresponding to the Egyptian market criteria was obtained from the class III logs, while for the Italian market criteria it was obtained from the class IV logs. All other sawn products were produced according to the criteria of Serbian market...