This study was designed to determine some physical and mechanical properties of laminated veneer lumber (LVL) made of black alder (Alnus glutinosa). Veneers were prepared from 2-mm and 4-mm-thick black alder and glued using polyvinyl acetate (PVA) and polyurethane (PU) adhesives. Results showed that the specific gravity and mechanical properties of the LVL produced from 2-mm veneers were higher compared to those from 4-mm veneers. In other words, as the thickness increases, a decrease is observed in the specific gravity and mechanical property values. Except for nail- and screw-holding strength values perpendicular to the glueline, all the other values obtained with the PVA adhesive were higher compared to those obtained with the PU adhesives.
In this study, the bending moment capacities under the diagonal compression and tensile loadings of the mitre frame corner joints with dovetail fi ttings were investigated. Solid poplar wood (Populus nigra) was used in the production of framework pieces. Recently, mitre frame corner joints with dovetail fi tting are preferred in practice. Th is has been infl uential in the making of this study. A total of 80 each mitre frame corner joint specimens with dovetail fi tting were prepared for this purpose. Of these, 20 were prepared with polyvinyl acetate (PVAC) adhesive, 20 were prepared with polyurethane (PU) adhesive, 20 were prepared with cyanoacrylate (CA) adhesive and 20 were prepared without adhesive (WA). Solid poplar wood (Populus nigra) was used as a frame material. Th e specimens were subjected to diagonal tensile and compression processes in the universal test machine in accordance with ASTM-D 143-94. Th e data obtained at the end of the tests were analyzed statistically and the results were evaluated. According to this, the highest bending moment capacity und er the diagonal compression loading (MC-L) (55.71 N · m) and bending moment capacity under the diagonal tensile loading (MC-T) (160.55 N · m) was obtained in the specimens bonded with PVAC adhesive. Whereas, the lowest MC-L (18.45 N · m) and MC-T (14.06 N · m) was obtained in the specimens without adhesive (WA). Th e diff erence between the MC-T and the MC-Cof the specimens bonded with the CA and PU adhesives was insignifi cant. Accordingly, it is defi nitely necessary to use adhesives in the bonding of dovetail fi ttings for obtaining a higher MC-T and MC-C. Th e best result among the available adhesives was obtained with the PVAC adhesive.
Abstract This research was carried out to find out the impact the mechanical densifying process has on wood material on the varnish adhesion resistance to surface. To this end, the experiment samples acquired from black pine (Pinus nigra) and Uludag Fir (Abies bornmulleriana Mattf) were subjected to densification in a hydraulic press at 140°C and a rate of 25% and 50% with a direction of radial. Following the process of densification, the sanded and unsanded samples were varnished with cellulosic and polyurethane varnishes, afterwards the surface adhesion resistance of the varnishes was determined. Regarding the three-way interaction between densification ratio, surface treatment and wood type, the highest surface adhesion resistance of the varnish layer was found in black pine + unsanded surface + 25% densification (1.98), and the lowest was in Uludag Fir + unsanded surface + 50% densification (0.99). Concerning the triple interaction of varnish type, concentration ratio and surface treatment, the highest surface adhesion resistance of the varnish layer was found in the polyurethane varnish + non-densified control group + sanded surface (2.23), and the lowest was in cellulosic varnish + non-densified control group + sanded surface (1.02). Approximate values were obtained for the densification process. It can be stated that the densification process creates high adhesion values for the polyurethane varnish in the black pine wood type. The sanding process has an intensifier effect on these values, and the products which were obtained from the polyurethane varnished samples do not require sanding. Considering these situations can provide significant advantages in projects with wood materials subjected to the densification process.
Turkiye Mobilya Sektoru, sahip oldugu ulusal ve uluslararasi pazar potansiyeli ve son yillarda surekli gelisim gosteren pozitif dis ticaret yapisi ile ulusal ekonomide onemli bir yer tutmaktadir. Sektorun ciktisi olan urunlere olan taleplerdeki degisimin yonunun ve buyuklugunun bilinmesi yatirim kararlarinin verilmesi, kar buyuklugu ve karliligin surekliligi acisindan onem arz etmektedir. Bu calismada; mobilya talebinde direkt olarak etkili bulunan kisi basina milli gelir, yenileme sikligi, yeni dogan sayisi, nufus artisi veya oturma izni verilen konut sayisi gibi parametrelere bagli olarak potansiyel talep yani sira uretim ve dis ticaretteki degisim degerleri erisimli ulusal ve uluslararasi veri kaynaklari kullanilarak derlenmistir. Derlenen verilerden sadece “oturma izni verilen konut sayilari” verileri, veri madenciligi uygulama sureci dahilinde istatistiksel yontemlerle analiz edilerek degisim fonksiyonlari turetilmis ve bu fonksiyonlarla da trend analizi yapilarak 2023 ongoruleri ortaya konmustur.
Hedef pazar, nispeten benzer ihtiyac ozellikleri gosteren musteri grubudur. Surekli ve tatmin edici seviyede kar elde etme, toplumsal hizmet, varligini surdurme ve ozel beklentilerini karsilama gibi isletmelerin bilindik amaclarini gerceklestirmedeki basari seviyesi sectigi hedef pazarin yapisal karakteristiklerinin dogruluguna bagli bulunmaktadir. Bu nedenle hedef pazar secimi isletmeler icin hayati onemdedir. Hedef pazar seciminde farkli kriterler olmasi ve bu kriterlerin etkisinin farkli stratejilere gore degismesi, sorunu cok kriterli stratejik karar verme boyutuna tasimaktadir. Bu calismada, karar problemi uzerindeki etkenlerin agirliklarinin tespiti icin Analitik Hiyerarsi Prosesi (AHP) ve en iyi alternatifin secimi icin ise farkli etkenlere gore belirlenen alternatiflerin siralanmasi ve secimi uzerine uygulanan VIKOR (Vise Kriterijumska Optimizacija I Kompromisno Resenje) yontemini bir arada kullanarak mobilya sektoru icin hedef pazar potansiyelinin gostergesi olan sehir secimine yonelik uygulama yapilmistir.
The effect of the number of blades and the abrasive grain size of sandpaper on the surface roughness in wood materials obtained from Lombardy poplar (Populus nigra L.) and European black pine (Pinus nigra A.) were examined. A total of 220 samples were prepared for this purpose. The samples were subjected to roughness measurements according to TS 6212 EN ISO 4288. The values obtained were statistically analyzed and the results were interpreted. The best results among the sanded surfaces in roughness were obtained with 180-grit sandpaper on tangential cut surfaces for Lombardy poplar and with 220-grit sandpaper on tangential cut surfaces for European black pine. In the planed surfaces, the best result was obtained on tangential cut surfaces with 2 blades and a 5 m min-1 feeding rate for Lombardy poplar and European black pine.
This research aimed to determine the impact of the mechanical densifying process of wood material on the varnish surface adhesion strength. Specimens from black pine (Pinus nigra) and Uludag fir (Abies bornmuelleriana Mattf.) were subjected to densification in a hydraulic press at 140 °C to the extent of 25% and 50% in the radial direction. While densification increased the surface adhesion strength of the varnish layer in black pine, the value decreased in fir. Regarding the interaction between densification ratio, surface treatment, and wood type, the highest surface adhesion strength of the varnish layer was found in black pine + unsanded surface + 25% densification, and the lowest was in Uludag fir + unsanded surface + 50% densification. It can be stated that the densification process creates high adhesion values for the polyurethane varnish in the black pine wood type. The sanding process has an intensifying effect on these values, and the products that were obtained from the polyurethane varnished samples do not require sanding. Considering these situations can provide significant advantages in projects with wood materials subjected to the densification process.
