Manufacture of laminated strand veneer (LSV) composite. Part 1: Optimization and characterization of thin strand veneers

Holzforschung ◽  
2008 ◽  
Vol 62 (6) ◽  
Author(s):  
Shilo W. Weight ◽  
Vikram Yadama
Keyword(s):  
Aspect Ratio ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Phenol Formaldehyde ◽  
Small Diameter ◽  
Parent Material ◽  
Modulus Of Rupture ◽  
Formaldehyde Resin ◽  
Old Growth Forest ◽  
Platen Temperature

Abstract The forest resources are changing due to fire prevention and depletion of old growth forest. Applications for small-diameter juvenile timber, especially for low-value species, such as ponderosa pine (Pinus ponderosa) are needed. In this study, a novel thin wood strand composite of P. ponderosa, 3.2 mm thick, is introduced as a veneer substitute. Optimization was performed for the processing parameters phenol formaldehyde resin content, platen temperature, and the aspect ratio strand length to thickness (L/t). Mean modulus of elasticity and modulus of rupture values of 10.2 GPa and 79.1 MPa, respectively, were obtained with the optimized formulation (5.5% resin, platen temperature 152°C, and aspect ratio of 430). These values were approximately 2–2.5 times higher than the parent small-diameter ponderosa pine lumber. The results indicate that fast-growing low-density species – such as hybrid poplars, or small-diameter timber with predominantly juvenile wood – could potentially be used to manufacture strand veneers of consistent quality with significantly higher strength and stiffness than parent material.

scholarly journals Properties of dual-species bamboo-oriented strand boards bonded with phenol formaldehyde adhesive under various compression ratios

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5422-5435
Author(s):  
Sena Maulana ◽  
Wahyu Hidayat ◽  
Ihak Sumardi ◽  
Nyoman J. Wistara ◽  
Muhammad I. Maulana ◽  
...  
Keyword(s):  
Compression Ratio ◽  
Phenol Formaldehyde ◽  
Slenderness Ratio ◽  
Physical And Mechanical Properties ◽  
Phenol Formaldehyde Resin ◽  
Modulus Of Rupture ◽  
Formaldehyde Resin ◽  
Thickness Swelling ◽  
Naoh Solution ◽  
Dendrocalamus Asper

Physical and mechanical properties were evaluated for bamboo-oriented strand boards (BOSB) prepared with combinations of two contrasting bamboo species and bonded with phenol formaldehyde resin under various compression ratios. The strands from the culms of Gigantochloa pseudoarundinacea and Dendrocalamus asper bamboo were steam-treated at a temperature of 126 °C and a pressure of 0.14 MPa for 1 h and then washed with a 1% NaOH solution. Three-layer dual-species bamboo-oriented strand boards with a shelling ratio of 25 to 50 to 25 (face to core to back) were manufactured with different compression ratios using an 8% phenol formaldehyde adhesive and 1% paraffin. The slenderness ratio and aspect ratio were evaluated by measuring 100 random strands to determine uniformity. The solidity profiles of the dual-species bamboo-oriented strand boards (thickness direction) were relatively uniform. The modulus of rupture, modulus of elasticity, and internal bond values of the dual-species bamboo-oriented strand boards increased as the compression ratio increased, but the water absorption and thickness swelling decreased. The dual-species bamboo-oriented strand boards prepared with compression ratios of 1.44 to 1.25 and 1.54 to 1.33 met all the requirements of CSA standard 0437 (2011). The optimum compression ratio for the preparation of dual-species bamboo-oriented strand boards was 1.44 to 1.25.

"Black Bark" Ponderosa Pine: Tree Grade Definition and Value Comparison with Old-Growth Trees

1994 ◽  
Vol 9 (1) ◽  
pp. 8-13 ◽  
Author(s):  
Susan Willits
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Control Sample ◽  
Small Diameter ◽  
Old Growth ◽  
Pine Tree ◽  
Common Grade ◽  
Small Diameter Trees ◽  
Crown Characteristics ◽  
Eastern Washington

Abstract A ponderosa pine (Pinus ponderosa) tree grade has been developed to separate lower value, small-diameter trees typical of young-growth stands from small-diameter old-growth trees. The tree grade uses a combination of bark, limb, and crown characteristics to identify the "black bark," trees. The tree grade was tested in two shop type mills and one dimension mill in southern Oregon and eastern Washington. Significant differences in value were found between the sample of black bark pine and the grade 5 control sample. Differences in value increased with diameter because of increased opportunities to recover high-quality lumber from the larger old-growth trees. The dimension mill recovered more lumber volume from the smaller diameter logs because of fewer sawlines and smaller rough-green sizes. Even though the shop mills recovered lower volumes, they did recover higher value by producing Shop and Common grade lumber rather than standard Dimension grades. Overall the differences compensated for each other, and both mill types recovered roughly equal value from logs of similar grade and size. West. J. Appl. For. 9(1): 8-13.

scholarly journals Characterization of Prototype Formulated Particleboards from Agroindustrial Lignocellulose Biomass Bonded with Chemically Modified Cassava Peel Starch

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Stephen Warui Kariuki ◽  
Jackson Wachira ◽  
Millien Kawira ◽  
Genson Murithi Leonard
Keyword(s):  
Forest Cover ◽  
Phenol Formaldehyde ◽  
Lignin Content ◽  
Phenol Formaldehyde Resin ◽  
Modulus Of Rupture ◽  
Tree Cover ◽  
Formaldehyde Resin ◽  
Low Density ◽  
Wood Demand ◽  
Materials Used

Conventional methods of making particleboards utilize wood chips. This has resulted in a decrease in the tree cover due to the increase in wood demand. The effect has been climatic change. Wood is bound using phenol formaldehyde resin. Because of the decrease in the forest cover, alternative lignocellulose materials are required. In this study, lignocellulose materials used include sugarcane bagasse, maize stock, and rice husks. The cassava-starch mix with borax was used as a binder in particleboard formulation. The lignin content was determined, and its effect on properties of boards was investigated. The resultant composite material was molded at a pressure of 6.5 N/mm2 and at 30°C. The resultant particleboards had mean densities ranging from 0.604 to 0.611 g/cm3. The modulus of elasticity ranged from 2364.2 N/mm2 to 3329.93 N/mm2, modulus of rupture ranged from 13.55 N/mm2 to 14.83 N/mm2, and internal bonding ranged from 1.613 N/mm2 to 2.370 N/mm2. The performance of the board was dependent on the lignocellulose material used. Fourier transform infrared spectroscopy analysis showed that main chemical bonding in the particleboard resulted from esterification of –COOH from lignocellulose and OH- from starch. The particleboards formulated were found to be of low-density-fibre standard used in a similar manner to the conventional low-density particleboards.

scholarly journals Synthesis, Characterization and Mechanical Evaluation of the Phenol-Formaldehyde Composites

2008 ◽  
Vol 5 (s1) ◽  
pp. S1015-S1020 ◽  
Author(s):  
B. S. Kaith ◽  
Aashish Chauhan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Wear Resistance ◽  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Phenol Formaldehyde ◽  
Phenol Formaldehyde Resin ◽  
Modulus Of Rupture ◽  
Formaldehyde Resin ◽  
Physico Chemical

Phenol: formaldehyde ratio was varied in the synthesis of phenol- formaldehyde resin and used to prepare the composites. These composites were then evaluated for their mechanical strength on the basis of tensile strength, compressive strength and wear resistance. Composite with better strength was characterized by IR, SEM, XRD, TGA/DTA and further studies were carried out for its physico-chemical and mechanical properties like viscosity, modulus of rupture (MOR), modulus of elasticity (MOE) and stress at the limit of proportionality (SP)etc.

scholarly journals Mechanical Properties Assessment of Laminated Veneer Lumber from Teak Plantation in Laos

2021 ◽  
Vol 18 (2) ◽  
Author(s):  
Khonethong SOUKPHAXAY ◽  
Khamtan PHONETIP ◽  
Latsamy BOUPHA ◽  
Lothim SAETERN ◽  
Khanxay KHAMMANIVONG ◽  
...  
Keyword(s):  
Phenol Formaldehyde ◽  
Phenol Formaldehyde Resin ◽  
Modulus Of Rupture ◽  
Bending Test ◽  
Formaldehyde Resin ◽  
Test Results ◽  
Forest Plantation ◽  
Machine Model ◽  
Laminated Veneer Lumber ◽  
Teak Plantation

The objective of this study was to investigate the most influenced levels of pressure and length of time on modulus of rupture (MOR) and modulus of elasticity (MOE) of teak laminated veneer lumber (LVL). Teak LVL was taken from the Faculty of Forestry’s forest plantation in Vientiane, Laos. The peeled veneer’s thickness was 2.3 mm. The veneer was air-dried until the moisture content reached the range of 6 to 10 %. Teak LVL panels were assembled from 9-ply panels of veneer using PL116- Liquid phenol-formaldehyde resin adhesive. The temperature was at 120 °C at 3 different pressure levels i.e., 1.5, 2 and 2.5 MPa and levels of time i.e. 9, 11 and 13 min. The experiment was conducted based on ISO16978. Intron Machine Model 5569 was used for the bending test of LVL with a dimension of 20×20×360 mm3. The bending test results on teak LVL showed significantly different MOR and MOE based on length of time and pressure levels of pressing.

scholarly journals Sifat Fisis dan Mekanis Oriented Strand Board Hibrida Bambu Pada Berbagai Shelling Ratio (Physical and Mechanical Properties of Hybrid Bamboo Oriented Strand Board at Various Shelling Ratios)

2021 ◽  
Vol 17 (2) ◽  
pp. 152-159
Author(s):  
Rynaldo Davinsy ◽  
Sena Maulana ◽  
Muhammad I Maulana ◽  
Elvara D Satria ◽  
Deded S Nawawi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Outer Layer ◽  
Oriented Strand Board ◽  
Phenol Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Outer Core ◽  
Phenol Formaldehyde Resin ◽  
Modulus Of Rupture ◽  
Formaldehyde Resin ◽  
Board Density

Hybrid Bamboo Oriented Strand Boards (OSB) were produced to improve bamboo OSB's physical and mechanical properties. Shelling ratio adjustment of the strand type combination could determine the optimal physical and mechanical properties of hybrid bamboo oriented strand boards (OSB). The purpose of this study was to evaluate the physical and mechanical properties of hybrid betung and andong bamboos OSB at various shelling ratios. Steam modified strands of betung and andong bamboo were used as an outer layer and core layer, respectively. Hybrid bamboo OSBs were prepared with 0.7 g cm-3 target density and 8% phenol-formaldehyde resin content. Three layers of OSB were made with outer: core shelling ratios of 30:70, 40:60, 50:50, and 60:40. The physical and mechanical properties of the OSB were tested referring to the JIS A 5908-2003 standard. The targeted board density was achieved and the physical properties of all hybrid bamboo OSB have met the requirement of CSA O437.0 (Grade O-1) standard criteria. The parallel modulus of elasticity (MOE) and modulus of rupture (MOR) increased with increasing outer layer ratio. However, the perpendicular MOE and MOR decreased with increasing outer layer ratio. The internal bonding (IB) of the OSB with a shelling ratio of 30:70 and 40:60 met with the requirement of the CSA O437.0 (Grade O-1) standard.

Effects of fuel characteristics on ember generation characteristics at branch-scales

2019 ◽  
Vol 28 (12) ◽  
pp. 941 ◽  
Author(s):  
Tyler R. Hudson ◽  
David L. Blunck
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Small Diameter ◽  
Quercus Alba ◽  
White Oak ◽  
Western Juniper ◽  
Crossflow Velocity ◽  
Fuel Characteristics ◽  
Time Required ◽  
Significant Factors

Spot fires caused by lofted embers (i.e. firebrands) can be a significant factor in the spread of wildfires. Embers can be especially dangerous near the wildland–urban interface (WUI) because of the potential for the fire to be spread near or on structures. This work sought to identify how ember generation changes for different fuel characteristics and environmental conditions. Samples were burned in a heated wind tunnel and the time required for the ember(s) to form was measured using a DSLR camera. A factorial analysis of variance was used to determine the sensitivity of the time to generation to species, diameter, moisture content, fuel condition (i.e. dowel v. natural sample), crossflow temperature and crossflow velocity. Four fuel species were evaluated: Douglas fir (Pseudotsuga menziesii), western juniper (Juniperus occidentalis), ponderosa pine (Pinus ponderosa) and white oak (Quercus alba). The diameter of the samples had the greatest effect on the time to generation and the fuel species had the second greatest effect. The small diameter samples were relatively insensitive to changes in other parameters. Natural samples required significantly longer time than dowels to generate an ember. These conclusions suggest that fuel morphology is one of the most significant factors influencing ember generation.

scholarly journals A note on the ecology and management of old-growth forests in the Montane Cordillera

2003 ◽  
Vol 79 (3) ◽  
pp. 441-454 ◽  
Author(s):  
André Arsenault
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Structural Characteristics ◽  
Coniferous Forest ◽  
Natural Disturbance ◽  
Climatic Conditions ◽  
Forest Types ◽  
Old Growth ◽  
Old Growth Forest ◽  
Old Growth Forests

The Montane Cordillera ecozone that spans British Columbia's central and southern interior and a portion of southwestern Alberta contains the greatest variety of old-growth coniferous forest types in Canada. The diverse climates of this region, which include some of the driest, warmest, wettest, and coldest found in southern continental Canada, have directly contributed to the richness of old forest types. Associated with this range in climatic conditions are radically different natural disturbance regimes that have profoundly influenced the distribution, abundance, and structural characteristics of old-growth forests. Old forests tend to be more abundant and to contain more old-growth-dependent organisms in wetter climates. The high number of old-growth-dependent epiphytic lichens in old inland rainforests is a clear expression of this phenomenon. Conversely, old forests are much less abundant in dry landscapes. These forests, often dominated by Ponderosa pine (Pinus ponderosa P. Laws. ex C. Laws.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), have been subject to more frequent natural disturbances, and have been more profoundly influenced by human activities. Although fewer species appear to be dependent on old growth in dry forests, a number of them require certain old-growth structural attributes for their survival. A better understanding of the ecological characteristics of the old-growth forests of Canada's Montane Cordillera will assist in developing informed land-use decisions. Key words: old-growth forest, Montane Cordillera, natural disturbance, landscape ecology and management

scholarly journals Processing Value of Small-Diameter Sawtimber at Conventional Stud Sawmills and Modern High-Speed, Small-Log Sawmills in the Western United States—A Comparison

2000 ◽  
Vol 15 (4) ◽  
pp. 208-212 ◽  
Author(s):  
Francis G. Wagner ◽  
Carl E. Fiedler ◽  
Charles E. Keegan
Keyword(s):  
United States ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
High Speed ◽  
Fire Suppression ◽  
Small Diameter ◽  
Selective Logging ◽  
Western United States ◽  
Forest Composition ◽  
Delivery Costs

Abstract Past selective logging of early successional species [e.g., ponderosa pine (Pinus ponderosa)] and effective fire suppression have dramatically altered forest composition and health over millions of acres in the western United States. Implementation of ecological restoration treatments to address these conditions will produce large volumes of small-diameter sawtimber for processing. Since sawmills currently process a majority of sawtimber harvested in the West (more than 80% in some regions), this study concentrated on determining the value of small-diameter sawtimber delivered to sawmills. A conventional stud sawmill and a modern, high-speed, small-log sawmill were profiled. A simulator (MSUSP) was employed to describe these sawmills and to determine breakeven delivered-sawtimber values by dbh class for each sawmill. Data inputs included machinery type, mill layout, machine speeds, volume and grade recovery, product prices, and fixed and variable manufacturing costs. Results showed that sawtimber 9 in. dbh and under could not cover harvest and delivery costs and earn even a modest (10%) return on invested (ROI) capital at the conventional stud sawmill and that sawtimber 7.5 in. dbh and smaller had negative values. However with a 10% ROI capital, the value of all sizes of sawtimber at the modern, high-speed sawmill equaled or exceeded harvest and delivery costs. West. J. Appl. For. 15(4):208–212.

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