scholarly journals Surface properties of poplar wood after heat treatment, resin impregnation, or both modifications

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 7562-7577
Author(s):  
Shuai Cao ◽  
Jiabin Cai ◽  
Meihui Wu ◽  
Nan Zhou ◽  
Zhenhua Huang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Surface Properties ◽  
Urea Formaldehyde ◽  
Formaldehyde Resin ◽  
Poplar Wood ◽  
Resin Impregnation ◽  
Heat Treated ◽  
Populus Tomentosa Carr ◽  
Heat Treatment Sample

To investigate the surface properties of different modified poplar (Populus tomentosa Carr.) wood samples, the color, surface roughness, and wettability of untreated poplar wood (control) and poplar modified via heat treatment, resin impregnation, and impregnation combined heat treatment were analyzed and compared in this study. The impregnant used in the test was a modified urea-formaldehyde resin with a low molecular weight and low viscosity. The results showed that the lightness of the samples was sorted in order as follows: the control was lighter than the resin impregnated sample, which was lighter than the impregnation combined heat treatment sample, which was lighter than the heat treatment sample. The surface of the control samples was relatively smooth, while after the impregnation, heat, and impregnation combined heat treatments, the Ra and Rz values increased, which indicated increased surface roughness due to the modifications. Among them, the heat-treated samples had the roughest surface, and the surface roughness of the impregnation combined heat treated samples at 160 °C had no major difference from the resin impregnated sample. The wettability of the samples decreased after heat treatment and increased after impregnation combined heat treatment. It was concluded that after the modification treatments, the color of the wood became darker, and the surface roughness and hydrophobicity increased.

scholarly journals Effect of Optical and Morphological Control of Single-Structured LEC Device

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 843
Author(s):  
Woo Jin Jeong ◽  
Jong Ik Lee ◽  
Hee Jung Kwak ◽  
Jae Min Jeon ◽  
Dong Yeol Shin ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Surface Properties ◽  
High Efficiency ◽  
High Surface ◽  
Reduction Rate ◽  
Operating Characteristics ◽  
Emission Layer ◽  
Light Emitting ◽  
Stable Operating

We investigated the performance of single-structured light-emitting electrochemical cell (LEC) devices with Ru(bpy)3(PF6)2 polymer composite as an emission layer by controlling thickness and heat treatment. When the thickness was smaller than 120–150 nm, the device performance decreased because of the low optical properties and non-dense surface properties. On the other hand, when the thickness was over than 150 nm, the device had too high surface roughness, resulting in high-efficiency roll-off and poor device stability. With 150 nm thickness, the absorbance increased, and the surface roughness was low and dense, resulting in increased device characteristics and better stability. The heat treatment effect further improved the surface properties, thus improving the device characteristics. In particular, the external quantum efficiency (EQE) reduction rate was shallow at 100 °C, which indicates that the LEC device has stable operating characteristics. The LEC device exhibited a maximum luminance of 3532 cd/m2 and an EQE of 1.14% under 150 nm thickness and 100 °C heat treatment.

scholarly journals Tribological Behavior and Analysis on Surface Roughness of CNC Milled Dual Heat Treated Al6061 Composites

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
A. Bovas Herbert Bejaxhin ◽  
G.M. Balamurugan ◽  
S.M. Sivagami ◽  
K. Ramkumar ◽  
V. Vijayan ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Lower Surface ◽  
Cnc Machining ◽  
Depth Of Cut ◽  
Good Surface ◽  
Heat Treated ◽  
Good Surface Finish ◽  
Artificial Neural Network Ann ◽  
Machining Properties

Dual heat treatment (DHT) effect is analyzed using the machining of Al6061-T6 alloy, a readily available material for quickly finding the machining properties. The heat treatments are conducted twice over the specimen by the furnace heating before processing through CNC machining. The HSS and WC milling cutters are preferred for the diameter of 10 mm for the reviewed rotational speeds of 2000 rpm and 4000 rpm, and the constant depth of cut of 0.5 mm is chosen based on various reviews. Worthy roughness could be provided mostly by the influence of feed rates preferred here as 0.05 mm/rev and 0.1 mm/rev. The influencing factors are identified by the Taguchi, genetic algorithm (GA), and Artificial Neural Network (ANN) techniques and compared within it. The simulation finding also helps to clarify the relationship between influenced machining constraints and roughness outcomes of this project. The average values of heat treated and nonheat treated Al6061-T6 are compared and it is to be evaluated that 41% improvement is obtained with the lower surface roughness of 1.78975 µm and it shows good surface finish with the help of dual heat treatment process.

Biocompatibility Comparison of Stainless Steel, Gold-Coated, and Heat-Treated Gold-Coated Endovascular Stents

2001 ◽  
Vol 711 ◽  
Author(s):  
Alisa S. Morss ◽  
Philip Seifert ◽  
Adam Groothius ◽  
Danielle Bornstein ◽  
Campbell Rogers ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Stainless Steel ◽  
Inflammatory Response ◽  
Neointimal Hyperplasia ◽  
Vascular Response ◽  
Gold Coating ◽  
Endovascular Stents ◽  
Heat Treated ◽  
Negative Effect

ABSTRACTEndovascular stents can be altered to improve radioopacity by applying a gold coating. We examined the vascular response in porcine coronary arteries to implantation of 9 mm NIR® stents that were either left intact, gold-coated, or heat-treated following gold coating. Our results show that while gold coating exacerbates neointimal hyperplasia and the inflammatory response, heat treatment removes this negative effect. Heat treatment was shown to increase the diffusion at the gold-steel interface and reduce the surface roughness.

Analysis of Cutting Parameters Influence on the Machined Surface Roughness Obtained by Turning of a Heat Treated Bearing Steel

2015 ◽  
Vol 809-810 ◽  
pp. 195-200
Author(s):  
Constatin Rotariu ◽  
Sevasti Mitsi ◽  
Dragos Paraschiv ◽  
Octavian Lupescu ◽  
Sergiu Lungu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Hard Turning ◽  
Cutting Parameters ◽  
Bearing Steel ◽  
Machined Surface ◽  
Heat Treated ◽  
Machined Surface Roughness ◽  
Bearing Rings ◽  
Quality Surface

In this paper we analyze the influence of cutting parameters on the surface quality, surface roughness respectively, processed by turning when heat treated bearing steel, also called hard turning, and processing by turning of bearing steel without heat treatment. We set parameters of the cutting regime influencing the achievement of roughness surfaces which must be within the predetermined requirements if bearing rings exceeding 500 mm in diameter. This analysis will be done by statistical methods using the software Minitab 14.

scholarly journals Heat Treatment Effect on the Surface Properties of Carbon Cloth Electrode for Microbial Fuel Cell

2021 ◽  
pp. X
Author(s):  
Shih-Hang CHANG ◽  
Yuan-Ting TSAO ◽  
Kuan-Wei TUNG
Keyword(s):  
Heat Treatment ◽  
Surface Properties ◽  
Microbial Fuel Cells ◽  
Large Scale ◽  
Carbon Cloth ◽  
Water Contact ◽  
Angle Measurements ◽  
Heat Treated ◽  
Contact Angle Measurements ◽  
Treated Carbon

In this study, we investigate the effect of heat treatment on the surface properties of carbon cloth electrodes and on the power generation efficiencies of microbial fuel cells (MFCs) configured with the heat-treated carbon cloth electrodes. Water contact angle measurements show that the hydrophobic surfaces of the carbon cloth became super-hydrophilic after heat treatment at a temperature above 500 °C, making it suitable for bacterial propagation. X-ray photoelectron spectrometry revealed that the signal of the C-O functional group of the carbon cloth electrodes increased in intensity after heat treatment. The MFCs configured with heat-treated carbon cloth electrode exhibited high power density of 16.58 mW/m2, whereas that of the untreated MFCs was only 8.86 mW m2. Compared with other chemical modifications, heat treatment does not use any environmentally unsound acidic or toxic solutions during modification and are promising for manufacturing large-scale MFC stacks.

Effect of conditioning history on the characterization of hardness of thermo-mechanical densified and heat treated poplar wood

Holzforschung ◽  
2017 ◽  
Vol 71 (6) ◽  
pp. 515-520 ◽  
Author(s):  
Tao Li ◽  
Jia-bin Cai ◽  
Stavros Avramidis ◽  
Da-li Cheng ◽  
Magnus E.P. Wålinder ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Relative Humidity ◽  
Assessment Method ◽  
Poplar Wood ◽  
Climate Chamber ◽  
Heat Treated ◽  
Specific Assessment ◽  
One Step ◽  
Modified Wood

Abstract Poplar wood was modified by a combination of thermo-mechanical densification (TMD) and heat treatment (HT) process at five temperatures ranging from 170 to 210°C. A new two-step conditioning method (CM) is suggested, in the course of which the modified wood is submitted to 50°C/99% RH→25°C/65% RH, where RH means relative humidity in the climate chamber. The traditional one-step CM (25°C/65% RH) served as reference. The effects of conditioning history on hardness were observed and analyzed along with the change of dimensional stability. The hardness of the modified wood was lower in the case of the proposed CM due to more set-recovery release, but the extent of that decreased with the HT temperature. For a good hardness, HT200°C should be selected with the proposed CM, which is different from the optimization output of 180°C obtained from the traditional CM. In conclusion, a specific assessment method for the performance characterization of this type of modified wood would be beneficial for the combined TMD and HT processes.

scholarly journals Surface roughness and wettability of surface densified heat-treated Norway spruce (Picea abies L. Karst.)

2019 ◽  
Vol 70 (4) ◽  
pp. 377-382
Author(s):  
Nadir Ayrilmis ◽  
Mirko Kariz ◽  
Jin Heon Kwon ◽  
Manja Kitek Kuzman
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Picea Abies ◽  
Cold Water ◽  
Longitudinal Direction ◽  
Tangential Direction ◽  
Treatment Temperature ◽  
Densified Wood ◽  
Surface Densification ◽  
Heat Treated

Surface roughness and wettability of the heat-treated and then surface densified spruce (Picea abies L. Karst.) wood were measured to determine the effect of densification and heat-treatment on wood surface properties. The process of heat-treatment with an initial vacuum was performed in a vacuum chamber on oven dried lamellas with dimensions of 630 mm (longitudinal direction) x 45 mm (tangential direction) x 25 mm (radial direction). The lamellas were heat-treated at four different temperatures which were 170 °C, 190 °C, 210 °C and 230 °C. Control specimens were not exposed to heat-treatment. The lamellas were first heated to 100 °C, the creation of a vacuum taking 30 min at this temperature, and then heated to the desired temperature, and treated at this constant temperature for 3 h. The lamellas were then cooled down by using coils with cold water inside the chamber. Surface densification of lamellas with compression from 22 mm to 15 mm thickness was made by press platens heated at 150 °C and held in that position for 60 s. After the 1 min, the heated platen was cooled to 90 °C, whilst the specimen remained under compression to minimize immediate spring back. The total time of compression was 2 min (30 s closing, 60 s pressing and approx. 30 s cooling). In the treatment groups, the optimum treatment temperature on the one-side densified wood specimens was found to be 170 °C based on the surface roughness and wettability values. Surface densification significantly decreased the surface roughness of the wood specimens. The surface quality of wood can be improved when the wood is exposed to the heat-treatment and then surface densification.

scholarly journals Effect of Sanding Processes on the Surface Properties of Modified Poplar Coated by Primer Compared with Mahogany

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 856 ◽  
Author(s):  
Qingqing Liu ◽  
Di Gao ◽  
Wei Xu
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Surface Treatment ◽  
Surface Properties ◽  
Equilibrium Contact Angle ◽  
Density Parameter ◽  
Distilled Water ◽  
Poplar Wood ◽  
Surface Pretreatment ◽  
Average Spacing

The surface roughness, static and dynamic liquid wettability of modified poplar wood were measured by different surface treatment of brushing primer and sanding. With the increase of the number of grinding paper, the depth parameters Ra, Ry, Rz and Rp of surface roughness of modified poplar decreased, and the density parameter Sm (the average spacing of micro unevenness of contour) decreased at first and then increased. With the increase of number of the grinding paper, the contact angle of water and glycerol for modified poplar wood decreased at first and then increased. After the modified poplar wood was brushed with the primer and sanded with 240# sandpaper, the density parameter Sm was 0.307, the equilibrium contact angle of distilled water was 34.88, and the equilibrium contact angle of glycerin was 36.46, all of which were the lowest number. At this time, the surface roughness was improved, and the modified poplar has the good wettability that is greater than the mahogany wood wettability. Compared with mahogany, the rough depth parameters of the modified poplar are smaller to those of mahogany, but the Sm of modified poplar wood is greater than that of the mahogany. After the same surface pretreatment, the wetting speed of glycerol on the surface of mahogany is higher than that of the modified poplar.

Effect of Technology Factors on the Resin Impregnation Results of Poplar

2013 ◽  
Vol 750-752 ◽  
pp. 2352-2356
Author(s):  
Jian Han ◽  
Kai Neng Liu ◽  
Xi Tao Gao
Keyword(s):  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Weight Percent Gain ◽  
Weight Percent ◽  
Phenol Formaldehyde Resin ◽  
Solid Content ◽  
Formaldehyde Resin ◽  
Test Pieces ◽  
Resin Impregnation ◽  
Impregnation Temperature

Aimed to improve the properties of Poplar, this study, taking phenol-formaldehyde resin (PF) and urea-formaldehyde resin (UF) as impregnation resin, probed the effect of the technology factors-vacuum time, solid content of resin, impregnation temperature and time on the impregnation results of Poplar, and the relationship between the resin and the wood was researched through infrared spectrum. The weight percent gain (WPG) of test-pieces increased with vacuum time extending, and WPG of the test-pieces were greatest when the solid content of resin was 30%, and the impregnation temperature was 25-30°C. when the impregnation time extended from 3 h to 9 h, WPG of the test-pieces presented increase trend which wasnt obvious. In this wood impregnated resin, the reaction between the resin and the hydroxy in wood formed ether bond binding, which proved that the resin and the wood occurred the chemical reaction.

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