Effects of drying methods of lamellas used in multilayer parquet manufacturing on surface roughness and bonding strength

The objective of this study is to determine surface roughness and bonding (tensile shear) strength of lamellas (top layer of multilayer parquet) which were cut away from green lumber and dried by different types of drying methods. Also, finding out the most convenient manufacturing method as surface roughness, bonding strength properties was aimed by comparing results with surface roughness and bonding strength of lamellas, which were cut away from dry lumber as seen in practice. Flat sawn green lamellas with 5 and 2 mm thicknesses, which were cut away from Iroko lumber by means of thin cutting frame saw, were dried with 3 different drying methods such as drying in lumber drying kiln, jet ventilated automatic veneer roller dryer and veneer press dryer. Effect of drying temperature on surface roughness and bonding strength was also determined by applying 3 different drying temperatures as 60, 100 and 140°C in jet ventilated automatic veneer roller dryer. In addition, lamellas with the same thicknesses were manufactured from dry lumber by means of the same thin cutting frame saw mentioned above. As the result of analysis of variance showed, differences between test groups were determined as surface roughness. Consequently, effect of drying method on surface roughness was found. Also, surface roughness values were determined to be increasing as drying temperature increases when drying in veneer roller dryer. Surface roughness values of lamellas dried in lumber drying kiln were found to be higher than those cut away from the dry lumber as expected. Differences exist between test groups as bonding strength was determined by means of analysis of variance. The biggest bonding strength was found in lamella group which were cut away from dry lumber and mentioned as comparison group. It was found that no relation existed between bonding strength and temperature increase drying in veneer roller dryer. Also, it was determined that no significant relation was found between surface roughness and bonding strength as the result of correlation analysis. Conclusively, it was found that lamella manufacturing method, cutting away from dry lumber, was the most convenient method for obtaining the best bonding strength in multilayer parquet production.Key words: Drying method, multilayer parquet, surface roughness, bonding strength

Effect of surface roughness on drying speed of drying lamellas in veneer roller dryer

Lamellas, which are defined as top layers of multilayer parquet and favourable to wood veneer can be dried in jet ventilated automatic veneer roller dryer due to short drying period. The objective of this study is to determine the effect of surface roughness on the drying speed of the veneer roller dryer. Quercus spp., frequently used tree specie in Turkish solid wood and multilayer parquet industries was chosen as material in this study. Pre-dried lamella blocks were cut into 4 different machines. As aresult, 4 test groups of lamellas displaying different surface roughness values were obtained. Lamellas which belong to each of these 4 test groups were also divided into 2 sub-groups and dried at 90 and 130°C drying temperatures. Drying was evaluated in relation to drying speed. Mitutoyo SJ 301 profilmeter was used for determining surface roughness values. Drying speed of lamellas was expressed as: dividing difference of initial moisture content and final moisture content values to dryingtime value. The result of variance analyses showed differences between groups as surface roughness values. There was no difference between groups as drying speed were determined at 90 and 130°C temperatures. Furthermore, the relation between surface roughness values and drying speed was searched using correlation analysis and no significant relationship was found. Finally, it was determined that there was no effect of surface roughness on drying speed in radial cut, pre-dried lamellas, which have surface roughness values between 10.464 and 15.064 ìm, drying in jet ventilated roller dryer, at 90 and 130°C temperatures

New collective structures in 179Au^179Au and their implications for the triaxial deformation of the 178Pt^178Pt core

The extremely neutron-deficient isotope Au179 has been studied by a combination of in-beam γ-ray and isomeric-decay spectroscopy. For in-beam spectroscopy, the recoil-isomer tagging technique was employed, using the known 3/2-, T1/2=328 ns isomer. A new rotational band, associated with the unfavored signature band of the 1h9/2?2f7/2 proton-intruder configuration, was revealed. A previously unknown, high-spin isomeric state with an excitation energy of 1743(17) keV and T1/2=2.16(8)μs was discovered. Five decay paths were identified, some of them feeding previously unknown non-yrast excited states, associated with the 1i13/2 proton-intruder configuration. Calculations based on the particle-plus-triaxial-rotor model were performed to interpret the data. On the basis of these calculations, the new 1h9/2?2f7/2 rotational band is interpreted as due to triaxial deformation of the underlying configuration with β2≈0.26 and γ≈27?. Observed non-yrast states of the positive-parity 1i13/2 intruder configuration are interpreted as due to triaxial deformation with β2≈0.26 and γ≈20?

Drying and Using Properties of Chestnut Wood

Drying is a process, which removes the water from the wood aiming maximum wood quality and minimum drying time and costs. Even though there are a number of commercial drying methods, technical drying methods are mostly used in the wood products industry. The most used technical drying method is also kiln drying (classical or conventional) method where drying schedules generally contain 4 steps: heating, drying, conditioning, and cooling. Principally in the drying chamber, air-water vapor mixture is used in ambient temperature of maximum 100 degrees C. On the other hand, chestnut is performed by two species named American (Castanea dentata (Marsh.) Borkh.) and Anatolian (Castanea sativa Mill.) chestnut and its wood is used for indoor and outdoor applications in Turkey because of its appearance and using properties. The raw materials from this tree species are needed drying to the final moisture content with regard to its using area. The aim of this study was to evaluate drying properties and drying schedules of chestnut wood and also give some information about its using areas related to its technological properties. In the study, various proper drying schedules based on lumber thickness were given and discussed. It is obvious that more protective drying conditions are needed in drying of C. sativa wood because of its higher density than C. dentata. Moreover it is clear that the temperatures are lower and equilibrium moisture contents are higher for C. sativa in the drying schedules when compared to C. dentata. Especially against collapse and inner checks, ambient temperature must be 43 degrees C at most until fiber saturation point in drying of C. sativa lumber while higher temperatures such as 54 degrees C can be applied for C. dentata