Oil Heat Treatment Research Articles

Yağlı Isıl İşlem Görmüş Sarıçam Odunlarında Koruyucu Katmanın Yapışma ve Sertlik Özellikleri

Wood is a preferred important material due to having many advantages for many uses. However, wood is degraded by time under the effects of biotic and abiotic factors. Therefore, wood should be protected from fungi, insects and other climate factors. Among these, heat treatment methods increase the durability of wood properties. Especially, oil heat treatment improves the dimensional stability and color stability in a positive direction. Thus, wood can be used for garden furniture or siding. In this study, water based varnish and paint were applied on oil heat treated scots pine (Pinus sylvestris L.) wood. Effects of oil heat treatment on adhesion strength and hardness of varnish and paint films were determined. Results showed that hardness of varnish layers (38) on oil heat treated scots pine wood is higher than paint layers (25.6)

Use of ATR-FTIR spectroscopy to detect the changes in extra virgin olive oil by adulteration with soybean oil and high temperature heat treatment

Abstract The structural changes induced in extra virgin olive oil (EVOO) by adulteration with soybean oil (SBO) and heat treatment at 185°C for 4 and 8 h were investigated using Attenuated Total Reflectance – Fourier Transform Infrared (ATR-FTIR) spectroscopy. Our results revealed that the band around 3006 cm–1 recorded shifts versus the percentage of adulterant. The changes in the absorbance at 3006 cm−1 (A3006) and in the ratio of the maximum heights of the bands at 3006 and 2925 cm−1 (A3006/A2925) were used to evaluate the EVOO adulteration. The regression analysis of A3006 and A3006/A2925 versus the percentage of adulterant was used to calculate the detection limits of adulteration. The time course of spectral changes showed that the oil heating caused notable modifications in the intensity of the absorption bands and induced no shifts in their exact position. The most relevant changes were reflected by conjugation and cis-trans isomerisation of double bonds, the formation of epoxides and widening of the band in the C=O region due to formation of secondary oxidation products. This study highlights that ATR-FTIR spectroscopy may be a promising means to differentiate among pure and adulterated oils and to study the thermooxidative processes in oils undergoing thermal stress.

Wettability of oil heat-treated bamboo and bonding strength of laminated bamboo board

In order to improve the interface properties of bamboo in laminated board applications for severe outdoor environment, bamboo sheets were heat treated in soybean oil and post oil extracted in this ...

Assimilation of the Production of Casing Pipe Resistant to the Action of Industrial Atmospheres Containing Hydrogen Sulfide

Features of structural and phase transformations, and also formation of a set of properties of Cr–Mo–V pipe steels are studied. Heat treatment regimes are developed for high-strength casing pipes for corrosion resistant application. Prospects are considered for application of computer simulation of production processes in a Visual Weld 9.0 program for developing and adjusting oil and gas pipe heat treatment regimes.

Oil Uptake Percentage in Oil-Heat-Treated Wood, its Determination by Soxhlet Extraction, and its Effects on Wood Compression Strength Parallel to the Grain

Oil heat treatment can effectively improve the dimensional stability and bio-durability of wood. However, the characteristics of high oil uptake (50 percent or higher) and high susceptibility to leaching from wood have an adverse effect on subsequent manufacturing processes of wood product and production costs. A solvent extraction (100% ethanol) process was used to extract the surplus oil from the treated wood. Because the making of powder specimens from high oil uptake wood would result in experimental error, a new method of determination of oil uptake percentage was proposed by two step Soxhlet extraction with ethanol. The oil uptake percentage of oil-heat-treated poplar wood at 180 oC for 2 h with this method was determined to be 113.29%. Additionally, the average oil uptake percentage (OUP) of oil-treated poplar after the oil extraction process for 2 and 6 h was 54.82% and 29.11%, respectively. Moreover, the average oil extraction percentage (OEP) of specimens with the oil extraction process at the first step (wood sticks) in the Soxhlet extractor apparatus was larger than that of oil-heat-treated poplar specimens. Due to the combined effect of chemical changes in the wood at high temperatures and of oil uptake by the wood, the compression strength parallel to the grain changed at different OUP levels.

Influence of Oil Lubrication and Heat Treatment on Wear Resistance of Thermally Sprayed Molybdenum Coating

To date, efforts forwarding to develop thermal spray coatings technology have been focused on increasing the durability and integrity of the coating. Improvement of mechanical characteristics such as wear resistance of the deposit, minimizing residual stress levels and reducing porosity are the main objectives of these works. The specific aim of this paper is to determine the wear resistance of molybdenum coating thermally sprayed on a steel substrate. This behavior has been determined using a simple ball-on-plate tribometer. Attention was given on the influence of a post-annealing at 850°C for one hour in vacuum and oil lubrication conditions.

CHANGES IN SWELLING PROPERTIES AND MOISTURE UPTAKE RATE OF OIL-HEAT-TREATED POPLAR (POPULUS × EURAMERICANA CV. PANNÓNIA) WOOD

In this work, the effect of oil heat treatment (OHT) on the swelling properties and changes in the rate of moisture uptake of poplar wood (Populus × euramericana cv. Pannónia) were investigated. Eighteen different treatments (combinations of three vegetable oils, two temperatures, and three durations) were studied. The results showed that OHT decreases the equilibrium moisture content (EMC) and the swelling of poplar wood. The degree of swelling and the EMC are influenced by both the duration and temperature of treatment. With an increase in duration and temperature, the EMC decreased. Consequently, the anti-swelling efficiency (ASE) increased. OHT wood adsorbs less moisture than natural wood, but it reaches a maximum – EMC at the momentary climate – at the same time under all the investigated treatments. The moisture uptake is fastest in the beginning and thereafter it slows significantly. Decreasing the moisture uptake by OHT wood is due to the decreasing of its water storage capacity.

Changes in Strength and Chemical Contents of Oil Heat Treated 15-year-old Cultivated Acacia Hybrid

Studies were conducted on the changes in strength and chemical contents of cultivated 15 year-old Acacia hybrid treated through oil heat treatment process. The timbers harvested and cut at the portions bottom, middle and top, were oil heat treated using palm oil for durations of 30, 60 and 90 min. at temperatures of 180, 200 and 220 oC. The untreated A. hybrid was used as control. The results of the studies showed that the oil heat treatment process causes some changes in the strength and chemical composition of the timbers. Strength reduction during the bending tests in both the MOR and MOE were noted throughout the treatment process. The chemical constituents of the treated timber also underwent changes in their contents. The holocellulose and cellulose degraded with the increasing of treatment temperature and duration in the oil heat treatment, while lignin showed the increment in content through this treatment. The changes in values of both the strength and chemical contents were influenced by temperature and duration of the treatment.

DENSIFICATION OF WOOD VENEERS COMBINED WITH OIL-HEAT TREATMENT. PART III: CELL WALL MECHANICAL PROPERTIES DETERMINED BY NANOINDENTATION

Compression under the effect of heat and steam, also called thermo-hygromechanical (THM) densification, can increase wood density and therefore improve its strength, stiffness, and hardness. Oil-heat treatment (OHT) is also known to reduce wood’s hygroscopicity and improve dimensional stability. A combination of both treatments can therefore produce wood with improved mechanical properties and dimensional stability. The objective of this project was to determine cell wall mechanical properties of THM-densified and OHT wood. Trembling aspen veneers were densified by a THM process and subsequently treated in canola oil at 200 and 220°C. Nanoindentations were performed in earlywood cell walls. The results show that cell wall longitudinal modulus of elasticity increased significantly from 13.5 GPa for the control to a maximum of 18.2 GPa for THM densified wood with or without OHT. Cell wall hardness increased from 0.27 GPa to a maximum of 0.43 GPa. Both THM densification and OHT significantly increased cell wall hardness. Therefore, the increase in mechanical properties of THM-densified and OHT wood can be due to an increase in wood density resulting from a reduction in porosity but also to an increase in the mechanical properties of the cell wall.

Densification of wood veneers combined with oil-heat treatment. Part II: Hygroscopicity and mechanical properties

In an effort to achieve high mechanical performance and improved dimensional stability, densification combined with . was determined. OHT at 180, 200, and 220ºC for 1, 2, and 3 hours was applied to densified Aspen (Populus tremuloides) veneers. OHT was found to be an efficient treatment to reduce the hygroscopicity of densified aspen veneers, although OHT had a negative impact on Brinell hardness. However, due to the contribution of densification, the hardness of oil-heat treated veneers was still two to three times higher than that of non-densified veneers. Similar results were found for tensile strength. Bending strength increased slightly at low OHT temperature, and then decreased at high temperature. Bending strength of oil-heat treated densified veneer samples was higher than that of non-densified ones. No significant effect of OHT was found on tensile MOE, but bending MOE increased after OHT. Compared to OHT duration, OHT temperature had a larger impact on densified wood hygroscopicity and mechanical properties.

Decay resistance and physical properties of oil heat treated aspen wood

The decay resistance of oil-heat treated aspen wood (Populus tremula l.) against white rot fungi (Coriolus versicolor) and brown rot fungi (Coniophora puteana) was investigated. Three different temperature stages and two time levels for oil heat treatment for the selection of optimum conditions were determined. Linseed oil as a heating medium was used. The mass loss of treated samples that were exposed to both fungi was significantly lower than that of the control samples. Results also showed improvement in dimensional stability after oil heat treatment. Decay resistance and dimensional stability of aspen wood were increased significantly with temperature increasing, but time seemed to have no effect on those properties. Oil heat treatment is a suitable method to improve decay resistance of aspen wood as it reduced the mass loss by 71% and 77% against Coriolus versicolor and Coniophora puteana compared with control samples, respectively. On the other hand, oil heat treatment improved the dimensional stability by about 20.5%.

Changes in chemistry, color, dimensional stability and fungal resistance of Pinus radiata D. Don wood with oil heat-treatment

Abstract Pinus radiata wood specimens were heat-treated at 160–210°C in linseed oil and the effects of treatment on chemical composition, color, dimensional stability, and fungal resistance were examined. The degradation of hemicelluloses was the most remarkable feature, which is the principal reason for alterations in wood properties. Removal or migration of extractives, oil uptake and the accumulation of oil on the wood surface were observed. The color of heat-treated wood became more uniform and darker, and its dimensional stability (i.e., anti-swelling efficiency) and fungal resistance were improved by up to 60% and 36%, respectively. The viscosity of the oil after treatment was elevated with the treatment temperature and was higher in comparison to heated oil without wood present.

Densification of wood veneers combined with oil-heat treatment. Part 1: Dimensional stability

is often a problem due to compression recovery. Alternatively, oil-heat treatment (OHT) improves wood dimensional stability and enhances resistance to biological attack. This study examined combined wood densification and OHT. Large wood veneer 700 700 mm specimens prepared with aspen (Populus tremuloides) were densified using heat, steam, and pressure at 160ºC, 180ºC, and 200°C, respectively. OHT at 180, 200ºC, and 220ºC for 1, 2, and 3h was then applied to the densified veneers. Results show that OHT efficiently improved dimensional stability and reduced compression set recovery. OHT temperature and duration markedly influenced the reduction of compression set recovery: the higher the OHT temperature and duration, the lower the recovery. Less than 5% recovery was obtained under various OHT conditions, and almost 0% recovery under some OHT conditions. Radial and tangential swellings of densified veneers were reduced dramatically. Compared to OHT duration, OHT temperature had a pronounced higher impact on radial and tangential swelling. Irreversible swelling (IS) in the compression direction of densified veneers decreased after OHT, particularly with high temperature and long duration, and anti-swelling efficiency (ASE) in the compression direction improved significantly.

The combined effects of boron and oil heat treatment on the properties of beech and Scots pine wood. Part 2: Water absorption, compression strength, color changes, and decay resistance

The effect of oil treatments on several properties of wood treated with boron compounds was studied: water absorption, water repellent efficiency, compression strength parallel to grain, color changes, and decay resistance against Coniophora puteana and Coriolus versicolor. Oil heat treatment evidently decreased the water absorption to approximately 20% and increased water repellent efficiency to 80–90% after 2 weeks immersion in water. Compression strength was not adversely affected by oil heat treatment at 160 °C. Oil impregnation as a second treatment step caused remarkable color changes especially in specimens pretreated with 5% boric acid. Boric acid treatment protected the specimens against brown and white rot when no leaching prior the decay test was used, but the protective effect was low when boron was leached. Oil treated specimens gave better efficiency against fungal decay compared to controls; however, the effect was not within the range of the efficacy needed for a wood preservative. Double treatment gave synergistic effect for both in unleached and leached specimens.

The combined effects of boron and oil heat treatment on beech and Scots pine wood properties. Part 1: Boron leaching, thermogravimetric analysis, and chemical composition

The aim of the study was to screen any possible synergistic effect available with combination of plant oils and boron compounds to decrease boron leaching and improve thermal degradation of wood by means of dual treatment. In order to reduce the leachability of boron compounds, sapwood of beech and Scots pine samples were treated with oils to create a hydrophobic layer on the wood cells that may prevent water uptake. Increase (%) of boron retained in double-treated samples after leaching was approximately 20% compared to boron-treated samples without oil. The most promising results on boron leaching obtained in the case of using waste and sunflower oil. Thermogravimetric residues were increased by the higher loading of boron compounds in double-treated samples. Spectra of FTIR-Photoacoustic spectrometer showed some deformation of lignin and cellulose followed by degradation of hemicelluloses of treated wood samples due to heat effect at 160 °C.

Color and Dimensional Stability of Oil Heat-Treated Radiata Pinewood after Accelerated UV Weathering

Pinus radiata specimens at a moisture content of 10 to 12 percent were heat treated at temperatures of 160°C, 180°C, and 210°C in commercial-grade raw linseed oil. The end-matched treated and untreated wood was exposed to an accelerated UV weathering environment for 2,100 hours using UV radiation and intermittent water spray. Changes in color and dimensional stability properties of the oil heat-treated wood were examined after (1) heat treatment and (2) accelerated UV weathering. The results show that the oil heat-treated wood turned darker and was more dimensionally stable. After oil heat treatment, the color of both the surfaces was uniform. Although color was darker on the surface than at the core, this contrast decreased with increasing treatment temperature. After the accelerated weathering test, the oil heat-treated wood retained its dimensional stability and color better than the untreated wood. No surface checks were observed in weathered treated wood, and volumetric swelling was also less compared with the untreated wood. Similarly, no color fading was observed in wood treated at 160°C and 180°C, while slight fading was noted for specimens treated at 210°C.

Enhancing Colour Appearances of Cultivated 15 year-old Acacia hybrid Through Oil Heat Treatment Process

This study investigated the effect of oil heat treatment process on colour appearance of cultivated Acacia hybrid. Parameters such as temperatures and treatment time are taken in account due to their influences in enhancing the colour chandes of the natural untreated and oil heat treated of the wood from sapwood right trough the heartwood. Young, natural and untreated Acacia hybrid would normally have the sapwood having lighter colour than the dark colour heartwood. Turning these timbers into plywood or furniture at this stage will resulted in uneven colour as the results of the mixture between the sapwood and heartwood. This will decrease the value of the products. Heating the wood at varying temperatures and treatment time would enhance the colour appearance of the young wood. The colour changes in the sapwood and heartwood were measured using Minolta Chroma-meter CR-310 and the results are presented according to the CIE L*a*b* colour co-ordinates system. The results revealed that the rising temperature at certain duration resulted in enhancing and darkening of wood tissues.

Effect of the fish oil, oxidation status and of heat treatment temperature on the volatile compounds of the produced fish feeds

This study aimed at giving information on the fish feeds’ volatile compounds and factors affecting them, since no respective data are currently available in the literature. Two different fish oils, a standard fish oil (FO) and a sardine oil (SO) were subjected to forced oxidation (50 °C and stirring for 120 h) and their non-oxidized and oxidized forms were incorporated in four produced fish feeds, respectively. The manufactured fish feeds were subjected to three different heat treatments (85, 115 or 140 °C). The SO diets had higher eicosapentaenoic (EPA 20:5 ω3) contents, higher total saturates and ω6 fatty acids and lower total monounsaturates, ω9 and docohexahenoic (DHA 22:6 ω3). Both oil oxidation and heat treatment resulted in higher TBA values in manufactured feeds. The volatile compounds characterizing the fish feeds were mainly hydrocarbons, carbonyls and alcohols, but also cyclic hydrocarbons, aromatics, ketones, esters ethers, furans, terpenes and miscellaneous compounds were present in lower quantities. The FO and SO diets differed (p<0.05) to their volatile profiles. In general sardine oil (SO) resulted in a higher number of feeds volatiles. Oxidation of the incorporated fish oil was found to have a significant impact on the volatile compounds. Among the above volatile compounds, butanal 2-methyl and toluene contents were affected by the fish oxidation status, the temperature of the heat treatment as well as by the interaction of these factors. These indicate that these two volatiles can be useful indexes of the feed quality.

Effect of Oil Heat Treatment on Physical properties of Semantan Bamboo (Gigantochloa scortechinii Gamble)

Effect of oil heat treatment on physical properties of 3 years old Gigantochloa scortechinii Gamble bamboo was investigated. The bamboo splits within epidermis were heat-treated using crude palm oil at temperature 140°C, 180°C and 220°C for duration 30 and 60 min. The objectives were to determine the effect of oil heat treatment on physical properties of the heat-treated bamboo and to assess any significant changes on physical properties of the heat-treated bamboo. Untreated bamboo was used as comparison for each treatment conditions. The results indicated equilibrium moisture content (EMC), density and volumetric shrinkage of heat-treated bamboo decreased as the treatment temperature and time increases. The EMC and density reduction were 4-27% and 11-18% approximately. This study indicated that bamboo became less hygroscopic when subjected to higher temperature and longer heat treatment time. Volumetric shrinkage of bamboo was also reduced by the treatment conditions (17-53%). The shrinkage properties of bamboo were inversely proportional to the treatment conditions, indicating that oil heat treatment successfully imparts the dimensional stability of the bamboo.

Effect of Oil Heat Treatment on Chemical Constituents of Semantan Bamboo (Gigantochloa scortechinii Gamble)

Effect of oil heat treatment on chemical constituents of 3 years old Gigantochloa scortechinii Gamble bamboo was investigated. The bamboo splits within epidermis were heat-treated using crude palm oil at temperature 140°C, 180°C and 220°C for duration 30 and 60 min. After removed the epidermis, the samples were then grind to pass a BS 40-mesh sieve and retained on a BS 60-mesh sieve. The sawdust was air dried for several days before conducted to chemical analyses (cellulose, hemicellulose and lignin) based on TAPPI Standard Methods. The colorimetric method devised by Humprey and Kelly (1960) was adapted to analysis starch in bamboo. Reading was obtained through Baush Lomb UV Spectrophotometer at 650 mm calculated by standard reference using A.R. potato starch. Control was used as comparison for each type of test conducted. There was no significant different between control and condition at 140°C for 60 min (81.4%) of holocellulose content. The value was decreased by 2.1 to 10.7% (79.7 to 72.7%) after heating at 180 to 220°C for 30 to 60 min. The hemicellulose content of bamboo was ranged 24.1 to 27.8% after heating at 140-220°C for 30 to 60 min. The cellulose content of heat-treated bamboo was ranged 47.4 to 55.2% after reduced about 2 to 14%. Lignin content increased about 16% (26%) at 220°C/60 min after reduced approximately 1 to 5% at 140 to 180°C for 30 to 60 min. Starch content was largely reduced about 2 to 54% (4 to 1.9%) at 140 to 180°C for 30 to 60 min of treatment. The results indicated that degradation of cellulose and hemicellulose of heat-treated bamboo was attributed to plasticization of lignin during heating in the same time hydrolysed the starch content.