Machining and related characteristics of five wood species from Bayanga region (Central African Republic) : final technical report YO-FS-89-JB-55

Torelli, Niko (author), Stewart, Harold A. (author)

The research represents an applied continuation of the study "Research on physical and mechanical properties of tropical wood species" completed in 1977. In accordance with ANSI/ ASTM D 1666-64 (Reapproved 1976) and Davis (1962), the working properties (planning, turning, shaping, boring) and nail and screw splitting tendency of nine Central African tree species: Albizzia adianthifolia, Blighia welwitschii, Celtis zenkeri, Detarium macrocarpum, Gilbertiodendron dewevrei, Irvingia gabinensis, Manilkara fouilloyana, Pachyleasma tessmannii and Xylopia hypolampsa were tested and compared with beechwood (Fagus sylvatica) and poplar wood (Populus nigra). Swelling and sorption properties were measured according to DIN 52 184 for the species enumerated above and the other 22 species: Albizzia sp., Anthostema aubryanum, Combretodendron africanum, Croton aubrevillei, Desplatsia floribunda, Dracaena mannii, Gambea beguei, Gambea boukokoensis, Ficus sp., Macarnaga barteri, Marquesia excelsa, Marinda lucida, Oldfieldia africana, Parkia filicoidea, Polyalthia suaveolens, Rauvolfia macrophylla, Stemonocoleus micranthus, Swartzia fistuloides, Tesmannia africana, Tesmania lescrauwaetii, Treculia africana, Tridesmodestemon emphalocarpoides from the first study. Five species were given preliminary testing to establish the possibility of producing peeled (Albizzia adianthifolia, Celtis zenkeri, Gilbertiodendron dewevrei, Pachyleasma tessmannii) and sliced veneer (Detarium macrocarpum, Gilbertiodendron dewevrei, Pachyleasma tessmannii). The deterioration resistance of the species Albizzia adianthifolia, Gilbertiodendron dewevrei and Irvingia gabonensis was evaluated according to ANSI/ ASTM D 2017-71 (Reapproved 1978). The study was commissioned by the U.S. - Yugoslav Joint Board on Scientific and Technological Cooperation and funded equally by the Science and Education Administration of SR Slovenia and the United States Department of Agriculture of the United States of America. The study was carried out with great help from the company "Slovenijales" or "Slovenia Bois" in the Central African Republic, who provided heavy mechanization in the field, its sawmill and veneer plant in Bayanga and finally the possibility of transport of wood to Slovenia. The Utensilia company and the carpenter cooperative in Vič, Ljubljana, made it possible to use the machines to conduct individual machinability tests. Cooperating scientist Harold A. Stewart of the Forestry Sciences Laboratory, Forest Service USDA, Southern Illinois University, Carbondale, U.S.A., gave us valuable advices in the final stage of the project during his visit to Ljubljana.

• Language: English
• Keywords: sorption, machinability, planning, turning, shaping, veneer production, Central African hardwoods, Albizzia adianthifolia, Blighia Welwitschii, Celtis zenkeri, Detarium macrocarpum, Gilbertiodendron dewevrei, Irvingia gabonensis, Manilkara fouilloyana, Pachyleasma tessmanni, Xylopia hypolamps
• Work type: Fundamental research
• Typology: 2.12 - Final Research Report
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: Biotechnical faculty, Department of wood science & technology
• Year: 1983
• Number of pages: 156 f.
• PID: 20.500.12556/RUL-144164
• UDC: 630
• COBISS.SI-ID: 2313609
• Publication date in RUL: 02.02.2023

Secondary language

• Language: Slovenian

Abstract

Raziskava je aplikativno nadaljevanje študije "Raziskave fizikalnih in mehanskih lastnosti tropskih vrst lesa", ki je bila končana leta 1977. V skladu z ANSI/ ASTM D 1666-64 (Reapproved 1976) in Davisom (1962) so bile ugotovljene obdelovalne lastnosti (struženje, skobljanje, rezkanje, vrtanje) ter nagnjenost nastanku razpok pri žebljanju in vijačenju devetih srednjeafriških drevesnih vrst: Albizzia adianthifolia, Blighia welwitschii, Celtis zenkeri, Detarium macrocarpum, Gilbertiodendron dewevrei, Irvingia gabinensis, Manilkara fouilloyana, Pachyleasma tessmannii in Xylopia hypolampsa ki so bile raziskane v primerjavi z lesom bukve (Fagus sylvatica) in topola (Populus nigra). V skladu s standardom DIN 52 184 so bile določene lastnosti nabrekanja in sorpcije za zgoraj naštete vrste in dodatnih 22 vrst: Albizzia sp., Anthostema aubryanum, Combretodendron africanum, Croton aubrevillei, Desplatsia floribunda, Dracaena mannii, Gambea beguei, Gambea boukokoensis, Ficus sp., Macarnaga barteri, Marquesia excelsa, Marinda lucida, Oldfieldia africana, Parkia filicoidea, Polyalthia suaveolens, Rauvolfia macrophylla, Stemonocoleus micranthus, Swartzia fistuloides, Tesmannia africana, Tesmania lescrauwaetii, Treculia africana, Tridesmodestemon emphalocarpoides iz prve študije. Pri petih vrstah je bilo opravljeno predhodno testiranje, da bi ugotovili možnost proizvodnje luščenega (Albizzia adianthifolia, Celtis zenkeri, Gilbertiodendron dewevrei, Pachyleasma tessmannii) in rezanega furnirja (Detarium macrocarpum, Gilbertiodendron dewevrei, Pachyleasma tessmannii). Odpornost vrst Albizzia adianthifolia, Gilbertiodendron dewevrei in Irvingia gabonensis proti razkroju je bila ocenjena v skladu z ANSI/ ASTM D 2017-71 (Reapproved 1978). Študijo je naročil Skupni odbor za znanstveno in tehnološko sodelovanje med ZDA in Jugoslavijo, v enakih deležih pa sta jo financirala Uprava SR Slovenije za znanost in izobraževanje ter Ministrstvo za kmetijstvo Združenih držav Amerike. Študija je bila izvedena z veliko podporo podjetja "Slovenijales" oziroma "Slovenia Bois" v Srednjeafriški republiki, ki je zagotovilo težko mehanizacijo na terenu ter svojo žago in obrat za proizvodnjo furnirja v Bayangi in nazadnje še možnost prevoza lesa v Slovenijo. Podjetje Utensilia in mizarska zadruga na Viču v Ljubljani sta omogočila uporabo strojev za izvedbo posameznih preizkusov obdelovalnosti. Sodelujoči znanstvenik Harold A. Stewart iz Laboratorija za gozdarske znanosti, Gozdarska služba USDA, Southern Illinois University, Carbondale, ZDA, nam je med obiskom v Ljubljani v zaključni fazi projekta dal dragocene nasvete.

• Keywords: sorpcija, obdelavnost, skobljanje, struženje, rezkanje, furnir, centralnoafriški listavci, Albizzia adianthifolia, Blighia Welwitschii, Celtis zenkeri, Detarium macrocarpum, Gilbertiodendron dewevrei, Irvingia gabonensis, Manilkara fouilloyana, Pachyleasma tessmanni, Xylopia hypolampsa