Impact of drying temperature and pressing time factor on VOC emissions from OSB made of Scots pine

Holzforschung ◽  
2006 ◽  
Vol 60 (4) ◽  
pp. 417-422 ◽  
Author(s):  
Mathias Makowski ◽  
Martin Ohlmeyer
Keyword(s):  
Scots Pine ◽  
Process Parameters ◽  
Elevated Temperatures ◽  
Oriented Strand Board ◽  
Time Factors ◽  
Drying Temperature ◽  
Voc Emissions ◽  
Pressing Time ◽  
Emission Testing ◽  
Volatile Aldehydes

Abstract Correlations between process parameters and VOC emissions from an oriented strand board (OSB) made of Scots pine (Pinus sylvestris L.) were demonstrated. Terpene and aldehyde emissions were affected by the pressing time factors in different ways: terpene emissions were lowered with elevated pressing times, whereas the formation of volatile aldehydes was accelerated. Drying temperature mainly affected the dynamics of aldehyde formation, with a clear rise and fall in aldehyde concentration after drying at elevated temperatures (170°C and >200°C). As a consequence of lower temperatures (120°C), aldehyde emissions from OSB constantly increased over the testing period. In spite of this context, a sustainable reduction in aldehyde emissions by adjusting the relevant process parameters does not seem to be feasible, as the concentrations released from all panels converged during emission testing.

Influences of hot pressing temperature and surface structure on VOC emissions from OSB made of Scots pine

Holzforschung ◽  
2006 ◽  
Vol 60 (5) ◽  
pp. 533-538 ◽  
Author(s):  
Mathias Makowski ◽  
Martin Ohlmeyer
Keyword(s):  
Surface Structure ◽  
Scots Pine ◽  
Hot Pressing ◽  
Fine Particles ◽  
Oriented Strand Board ◽  
Pressing Temperature ◽  
Voc Emissions ◽  
Emission Testing ◽  
Volatile Organic ◽  
Manufacturing Parameters

Abstract Oriented strand board (OSB) made of Scots pine (Pinus sylvestris L.) releases high amounts of terpenes and aldehydes. These volatile organic compound (VOC) emissions are clearly affected by the manufacturing parameters. As a consequence of high temperatures during hot pressing, terpene emissions from OSB are reduced. Aldehyde emissions are initially lowered after pressing at a high temperature (260°C). Furthermore, emissions are influenced by the surface structure. If the surface consists of fine particles, terpene emissions are lowered and the course of aldehyde formation is altered. Nevertheless, a reduction in VOC emissions by adjustment of the parameters investigated in this work seems to be restricted to terpenes. Aldehyde emissions from all panels converge during emission testing and in the final stages no clear distinction is possible according to the pressing temperature or surface structure.

Volatile Organic Chemicals Emissions from OSB as a Function of Processing Parameters

Holzforschung ◽  
1999 ◽  
Vol 53 (4) ◽  
pp. 441-446 ◽  
Author(s):  
A.O. Barry ◽  
D. Corneau
Keyword(s):  
Moisture Content ◽  
Oriented Strand Board ◽  
Processing Parameters ◽  
Resin Content ◽  
Drying Temperature ◽  
Pressing Time ◽  
Volatile Organic Chemicals ◽  
Preliminary Study ◽  
Resin Curing

Summary The effects of the oriented strand board (OSB) furnish drying temperature and moisture content on VOC emissions were evaluated and compared to those of the OSB pressing time and temperature and resin content. Results clearly showed the important role played by the drying temperature on the strand emissions. A decrease of emissions is observed when the furnish at a given original moisture content had been exposed to increasingly high temperatures. Also, the combined effect of moisture content and heating temperatures showed an increase of the detected TVOC as moisture content and the temperature increased. At a very high temperature however, the furnish at low moisture content started to degrade, and an increase in the emission level could be observed. The results showed that emissions from oriented strand board (OSB) panels were more sensitive to resin content and pressing time. The Box-Behnken statistical linear model used to treat the data revealed that a linear fitting better correlates our results. The correlation between the internal bond (IB) and the panel's emissions indicated a decrease in emissions as the quality of the board (IB) increases in agreement with better resin curing. The acquisition of more data will certainly be helpful to support this preliminary study.

Characterizing hydro-thermal compression behavior of aspen wood strands

Holzforschung ◽  
2009 ◽  
Vol 63 (5) ◽  
Author(s):  
Cheng Zhou ◽  
Gregory D. Smith ◽  
Chunping Dai
Keyword(s):  
Elevated Temperatures ◽  
Oriented Strand Board ◽  
Transverse Compression ◽  
Aspen Wood ◽  
Thermal Compression ◽  
Compression Behavior ◽  
End Products ◽  
Regression Approach ◽  
Fundamental Understanding ◽  
Strain Function

Abstract Wood-based composites, such as oriented strand board, are typically manufactured by consolidating mats of resinated wood elements under heat and pressure. During this process, the temperature and moisture content distributions within the mat greatly affect the properties of end products. To improve the fundamental understanding of mat consolidation during hot-pressing, a model is established to investigate the transverse compression behavior of aspen wood strands for a variety of combinations of temperatures (20–200°C) and moisture contents (0–15%). A regression approach is used to obtain the modulus-temperature-moisture relationship. In addition, elevated temperatures and moistures are found to influence the strain function of wood strands, which was previously assumed to be independent of these factors.

Effect of Coating Process Parameters on the Development of Residual Stresses in Ceramic Coatings

2019 ◽  
Author(s):  
Ali Gadelmoula ◽  
Khaled Al-Athel
Keyword(s):  
Residual Stresses ◽  
Process Parameters ◽  
Elevated Temperatures ◽  
Ceramic Coatings ◽  
Interface Roughness ◽  
Fe Model ◽  
Computational Framework ◽  
Scientists And Engineers ◽  
Coating Layers

Abstract Ceramic coatings are widely used in many engineering applications, especially applications related to components operating at elevated temperatures. One of the main issues relates to ceramic coatings is the development of residual stresses due to quenching and the thermal mismatch between the deposited coating layers and the substrate. In this work, a computational framework is developed to investigate the effect of various process parameters on the development of the residual stresses. The geometry of the coating layers and the interface roughness between the layers is first generated using SimCoat, a Monte Carlo based statistical algorithm that determines the effect of process parameters (droplet size, spraying speed, etc.) on the characteristics of the developed coating (coating thickness, porosity, etc.). An in-house code is used to convert the statistical data into a finite element (FE) model. Various FE models are generated with different process parameters, and the development of residual stresses is compared between them. The developed framework can be used by material scientists and engineers to predict the quality of the coating and optimize the process parameters to any specific application.

scholarly journals Resistance of thermally modified and pressurized hot water extracted Scots pine sapwood against decay by the brown-rot fungus Rhodonia placenta

2019 ◽  
Vol 78 (1) ◽  
pp. 161-171 ◽  
Author(s):  
Michael Altgen ◽  
Suvi Kyyrö ◽  
Olli Paajanen ◽  
Lauri Rautkari
Keyword(s):  
Cell Wall ◽  
Mass Loss ◽  
Scots Pine ◽  
Elevated Temperatures ◽  
Brown Rot ◽  
Decay Resistance ◽  
Hot Water ◽  
Decay Fungi ◽  
Effective Reduction ◽  
Cell Wall Porosity

AbstractThe thermal degradation of wood is affected by a number of process parameters, which may also cause variations in the resistance against decay fungi. This study compares changes in the chemical composition, water-related properties and decay resistance of Scots pine sapwood that was either thermally modified (TM) in dry state at elevated temperatures (≥ 185 °C) or treated in pressurized hot water at mild temperatures (≤ 170 °C). The thermal decomposition of easily degradable hemicelluloses reduced the mass loss caused by Rhodonia placenta, and it was suggested that the cumulative mass loss is a better indicator of an actual decay inhibition. Pressurized hot water extraction (HWE) did not improve the decay resistance to the same extent as TM, which was assigned to differences in the wood-water interactions. Cross-linking reactions during TM caused a swelling restraint and an effective reduction in moisture content. This decreased the water-swollen cell wall porosity, which presumably hindered the transport of degradation agents through the cell wall and/or reduced the accessibility of wood constituents for degradation agents. This effect was absent in hot water-extracted wood and strong decay occurred even when most hemicelluloses were already removed during HWE.

Additive Manufacturing of Nickel-Based Superalloys

2018 ◽  
Author(s):  
Benjamin Graybill ◽  
Ming Li ◽  
David Malawey ◽  
Chao Ma ◽  
Juan-Manuel Alvarado-Orozco ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Process Parameters ◽  
High Performance ◽  
Structural Integrity ◽  
Elevated Temperatures ◽  
Secondary Phases ◽  
Treatment Regimens ◽  
Operating Environments ◽  
Manufacturing Technologies

Additive manufacturing enables the design of components with intricate geometries that can be manufactured with lead times much shorter when compared with conventional manufacturing. The ability to manufacture components out of high-performance metals through additive manufacturing technologies attracts industries that wish to develop more complex parts, but require components to maintain their structural integrity in demanding operating environments. Nickel-based superalloys are of particular interest due to their excellent mechanical, creep, wear, and oxidation properties at both ambient and elevated temperatures. However, relationship between process parameters and the resulting microstructure is still not well understood. The control of the microstructure, in particular the precipitation of secondary phases, is of critical importance to the performance of nickel-based superalloys. This paper reviews the additive manufacturing methods used to process nickel-based superalloys, the influence of the process parameters on microstructure and mechanical properties, the effectiveness of various heat treatment regimens, and the addition of particles in order to further improve mechanical properties.

Drawability of Ti-6Al-4V Sheet at Elevated Temperatures

2010 ◽  
Vol 654-656 ◽  
pp. 902-905 ◽  
Author(s):  
Nho Kwang Park ◽  
Jin Gee Park ◽  
Sang Hyun Seo ◽  
Jeoung Han Kim
Keyword(s):  
Residual Stresses ◽  
Slip System ◽  
Process Parameters ◽  
Elevated Temperatures ◽  
Plastic Anisotropy ◽  
Drawing Ratio ◽  
Limit Drawing Ratio ◽  
Blank Holding Force ◽  
Forming Temperature ◽  
Increasing Temperature

Titanium and its alloys are difficult-to-form materials due to limited slip system and plastic anisotropy. Titanium is also prone to change in color due to oxidation at high temperatures. It is thus advisable to conduct deep drawing of titanium and its alloys at temperatures below 600°C. In this study, the drawability of Ti-6Al-4V sheet is evaluated in respect to the process parameters such as forming temperature, forming speed, and blank holding force at elevated temperatures. It is shown that the limit drawing ratio (LDR) increases with increasing temperature, but varies insignificantly with forming speed. The development of residual stresses in the wall of drawn cups during deformation was evaluated.

scholarly journals The impact of molded pulp product process on the mechanical properties of molded BCTMP

2020 ◽  
Author(s):  
Claire Dislaire ◽  
Yves Grohens ◽  
Bastien Seantier ◽  
Marion Muzy
Keyword(s):  
Mechanical Properties ◽  
Water Uptake ◽  
Process Parameters ◽  
Manufacturing Process ◽  
Water Immersion ◽  
Young Modulus ◽  
Drying Time ◽  
Pressing Time ◽  
Hygroscopic Properties ◽  
The Impact

Abstract This study was carried out using bleached softwood Chemi-Thermo-Mechanical Pulp to evaluate the influence of Molded Pulp Products’ manufacturing process parameters on the finished products’ mechanical and hygroscopic properties. A Taguchi table was done to make 8 tests with specific process parameters such as moulds temperature, pulping time, drying time and pressing time. The results of these tests were used to obtain an optimized manufacturing process with improved mechanical properties and a lower water uptake after sorption analysis and water immersion. The optimized process parameters allowed us to improve the Young’ Modulus after 1h immersion of 58% and a water uptake reduction of 78% with the first 8 tests done.

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