Wood Fiber Mats Research Articles

Size effect on the compressive strength of a novel structural wood composite: High-performance wood scrimber

High-performance wood scrimber (HPWS) is a novel wood composite that uses oriented wood fiber mats from veneers as raw material instead of the small-diameter timbers used in traditional wood scrimber. HPWS exhibits excellent mechanical properties and dimensional stability, making it a promising material for load-bearing components in construction. Similar to other biomass materials, the effect of size on the strength of HPWS is critical. As the volume of a member increases, the likelihood of fatal defects within it rises, resulting in a decrease in strength. However, there is a lack of knowledge regarding the size effect on HPWS. To address this issue, HPWS specimens with a broad range of sizes were tested to determine the effect of size on their compressive strength. Then, a random simulation method was applied to further investigate the source of the strength-dependency on size and to extrapolate the size effect to a wider range of sizes. Results indicated that both the size of the cross-sectional area and length significantly influenced the compressive strength of HPWS. The size effect strength-dependency was attributed to variations in the load redistribution capability between specimens with higher and lower strengths. The size effect of HPWS was found to be weaker compared to other structural wood or bamboo-based products. Calculation methods were proposed to quantify the size effect on HPWS. These findings lay a solid foundation for advancing the use of HPWS in construction.

Rapid determination of urea formaldehyde resin content in wood fiber mat using near-infrared spectroscopy

Monitoring the process is crucial for ensuring high quality in wood-based panel production. Interest in the distribution of resin in fibers and particles has increased during the last couple of decades. This study considered the potential to determine urea formaldehyde (UF) resin content in fiber mat using near-infrared (NIR) spectroscopy. Fiber mats with various resin contents were investigated with NIR combined with the partial least squares (PLS) regression and root mean square error of calibration and validation (RMSECV). The external factors, such as the distance between the fiber optic probe and the sample surface and light sources, were also evaluated. The results showed that this technique can sufficiently determine the resin content in the resinous fiber mat with accuracy of up to 95%. The light sources and the distances from the probe to the surface did not significantly influence the discrimination and prediction of resin content.

Fabrication, physical–mechanical properties and morphological characterizations of novel scrimber composite

Novel scrimber composites were fabricated by impregnating wood fiber mats with phenol formaldehyde (PF) resin. The effects of density and resin content on the physical–mechanical properties were studied. The morphological and bonding characteristics were investigated to analyze the microstructural changes and resin distribution. With increasing density and resin content, the dimensional stability and mechanical properties improved. As density and resin content neared the optimal values of 1.15 g/cm3 and 13%, respectively, scrimber composite showed excellent physical–mechanical properties. The PF resin impregnated the cracks and filled the voids of scrimber. The excellent physical–mechanical properties were ascribed to the wood fiber mats, impregnation with PF resin, and densified structure.

Laminating wood fiber mats into a densified material with high performance

To develop high-performance wood materials, a novel preparation strategy is presented in this study. Wood fiber mats impregnated with phenolic resin, were laminated into a densified material. Wood lumens collapsed layer by layer during densification, leading to a compact multi-layered structure. The densified material had excellent mechanical properties and favorable water resistance. The flexural, compressive, and short-beam shearing strength were approximately 230%, 400%, and 260% higher than that of natural wood, respectively. The water absorption rate and thickness swelling rate in boiled water were 19% and 5.7%, respectively. Surface water repellency was also enhanced due to reduction of hydrophilic groups on the surface. Such high performance makes the material a promising candidate for advanced engineering structures and applications.

Study of Hygrothermal Processes in External Walls with Internal Insulation

Abstract Being an important contributor to the final energy consumption, historic buildings built before 1945 have high specific heating energy consumption compared to current energy standards and norms. However, they often cannot be insulated from the outside due to their heritage and culture value. Internal insulation is an alternative. However internal insulation faces challenges related to hygrothermal behaviour leading to mold growth, freezing, deterioration and other risks. The goal of this research is to link hygrothermal simulation results with experimental results for internally insulated historic brick masonry to assess correlation between simulated and measured data as well as the most influential parameters. The study is carried out by both a mathematical simulation tool and laboratory tests of historic masonry with internal insulation with four insulation materials (mineral wool, EPS, wood fiber and granulated aerogel) in a cold climate (average 4000 heating degree days). We found disparity between measured and simulated hygrothermal performance of studied constructions due to differences in material parameters and initial conditions of materials. The latter plays a more important role than material parameters. Under a steady state of conditions, the condensate tolerating system varies between 72.7 % and 80.5 % relative humidity, but in condensate limiting systems relative humidity variates between 73.3 % and 82.3 %. The temperature between the masonry wall and all insulation materials has stabilized on average at +10 °C. Mold corresponding to Mold index 3 was discovered on wood fiber mat.

THE POSSIBILITY OF USING WOOD FIBER MATS IN PRODUCTS MANUFACTURING MADE OF POLYMER COMPOSITES BASED ON NUMERICAL SIMULATIONS

In this work the calculations for predicting the properties of wood fiber mats – polyester resin composite using numerical homogenization method were performed. For this purpose, the microstructural strength properties were calculated using DIGIMAT FE commercial code. In addition, for comparative purposes a calculation of polyester resin - glass fiber composites was conducted. This allowed to compare the properties of two types of compositions. In addition, the obtained strength properties were used to simulate the work of product made of these composites. This study was performed using the Ansys commercial code. Usability of the polyester resin - wood fiber mat composite and knowledge of its properties will allow to find a correct application of this composite type and can provide an alternative way to other polymeric resin reinforced by mat.

Scrimber board (SB) manufacturing by a new method and characterization of SB’s mechanical properties and dimensional stability

Abstract A novel process has been developed for manufacturing poplar wood scrimber boards (SBs), in the course of which thick veneers are produced first and then the oriented wood fiber mats (OWFMs) are fabricated in a pilot scale fluffing machine. A low molecular weight phenol-formaldehyde (PF) resin is applied for gluing and the cold-prepressing of the mats is followed by hot-curing between 120 and 130°C for 12 h. The mechanical properties and dimensional stability of the SBOWFMs were measured. The new process resulted in significantly better mechanical properties of SBOWFMs compared with those of raw wood and other poplar wood-based composites. All data including the dimensional stability of SBOWFMs increased with increasing density.

The possibility of using wood fiber mats in products manufacturing made of polymer composites based on numerical simulations

The possibility of using wood fiber mats in products manufacturing made of polymer composites based on numerical simulations

The Use of Composit Materials Alternative Fiberglass (Coco Fibers & Rags) on Fiberglass Ship in Traditional Shipyards Bengkalis Regency

The limitations of the current wood raw material nowadays is a threat to the traditional shipbuilding business. Besides the material is expensive, it is also about the difficulty in bringing the major raw materials, fiberglass, suchas wood fiber MAT and WR ( Woven Roofing). There is plan issues to ban on the use of the fiber within a certain period that accelerate the research in making the solution to be environment- free fiber. By doing the mechanical testing of coco fibre and rags, then gained streghth the bending and optimal impact and eligible BKI standard and ASTM D- 790 and ASTM D 638 and also the use of fiberglass reinforcement material fiber alternative is expected to save expenses in making that fiberglass. To reduce the environmental waste product that do not decompose in maintaining our health (avoiding toxic substances) against syntetic fiber. The result of bending test of composit and coir fabric is getting by using Bending Elasticity Modulus with average rags of hijab 12,88 Mpa, coco fibre 2,69 Mpa and fiber fabric undershirt 6, 57 Mpa, whereas for testing the impact obtained average value of rags hijab 0,0808 kg/mm 2 coco fibiers-0,16533 kg/mm 2 and fiber fabric undershit 0, 00427 kg/mm 2

Development of Novel Filter Materials for the Treatment of First-Flush Rainwater

First-flush rainwater is of great interest in the research on urban environmental protection and rainwater harvesting. It deteriorates the chemical, physical, and microbiological quality of the collected/stored water as well as the water body in an urban area. Accordingly, effective and economic treatment of first-flush rainwater is highly required. This study aimed to develop a technology for the treatment of first-flush rainwater using new filters made of wood fiber mat, dental cotton, and feldspar. The removal of pollutants in first-flush rainwater with each filter material was evaluated. Experiments were carried out using an artificial rainwater solution made of road dust particles (less than 200 um small) and D.I. water that contained ionic species. The SS concentration of the solution was set between 30 and 150 mg/L. Prior to the experiments, the fiber materials were pretreated with NaOH, FeCl3, and Al2O3. The batch test results indicated that the phosphate removal efficiency of the wood fiber mat was 8.6%; of the dental cotton, 34.7%; and of the feldspar, 1.7%. On the other hand, the heavy metal removal efficiency of the wood fiber mat was 91%; of the dental cotton, 26%; and of the feldspar, 0%. The highest cation exchange capacity of the wood fiber mat that was pretreated with NaOH was attributed to the existence of carboxyl and hydroxyl functional groups in the wooden polymers. Combinations of filter materials were found to have been effective in removing particles in the rainwater. The combination of the wood fiber mat with polyethylene beads resulted in 97-98% particle removal. Other combinations such as DP (dental cotton and polyethylene beads), MF (wood fiber mat and feldspar), and DF (dental cotton and feldspar) showed particle removal rates of 90-95%, 84-96%, and 87-94%, respectively. After 30 minutes, all the combinations had a particle removal rate of over 90%.

Investigating the link between pulp mill effluent and endocrine disruption: Attempts to explain the presence of intersex fish in the Wabigoon River, Ontario, Canada

The ability of some pulp mill effluents (PME) to act as reproductive and endocrine disrupters in fish is well documented in the literature. However, changes are not always consistent with regard to species, gender, hormones, or reproductive effects. In the present study, the presence of the first intersexed fish that, to our knowledge, has been found in a Canadian river exposed to PME, is reported. A field survey of the Wabigoon River near Dryden, Ontario, in the fall of 2000 found intersexed walleye (Sander vitreus vitreus) with significantly altered hormone levels and reduced gonad size. The Wabigoon River receives discharge from a bleached kraft pulp and paper mill and a municipal wastewater (MWW) plant. It also has historical sediment contamination (wood fiber mats) contributing to extended periods of low dissolved oxygen under low flow, drought conditions. A mesocosm-based partial life cycle test exposing fathead minnows (Pimephales promelas) to reference water, 20% effluent volume to river volume (v/v), 40% (v/v), or 60% (v/v) PME as well as a field survey of the walleye in the Wabigoon River were conducted. The only change in our mesocosm exposure was a decrease in testosterone in males with increasing effluent concentration and vitellogenin induction in males exposed to 60% (v/v) effluent. These results did not reflect the magnitude of endocrine disruption seen in the wild fish survey. Several hypotheses that may explain these discrepancies are proposed. Specifically, evidence is offered from published studies indicating that either hypoxia or MWW, alone or in combination with PME, may explain the discrepancy between our field experiment and the wild fish survey. The present study illustrates the complexities of multistressor receiving environments and the need for the development of cumulative effects assessment approaches.

Influence of fiber type, fiber mat orientation, and process time on the properties of a wood fiber/polymer composite

A rapid press consolidation technique was used to produce composites from two types of air-laid wood fiber mat, incorporating either mechanically refined or bleached chemi-thermomechanically refined Norway Spruce [Picea abies (L.) Karst] and a bicomponent polymer fiber. The manufacturing technique involved pre-compression, contact heating to the process temperature under vacuum and then rapid transfer to the press for consolidation and cooling. Composites were tested to determine response to water or water vapor, porosity, fiber volume fraction and tensile properties. The composites absorbed water rapidly and showed changes in thickness with fluctuations in relative humidity. Porosity was higher in composites containing mechanically refined (MDF) fibers than in composites containing bleached chemi-thermomechanically refined (CTMP) fibers. Tensile test results suggessted that fiber wetting by the polymer matrix had been maximized within a five-minute heating time. Results also indicated that had been maximized within a five-minute heating time. Results also indicated that porosity was not the key determinant of tensile properties in the composites.

The Effect of Mulch Type for Turfgrass Establishment within a Refined Wood Fiber Mat over Plastic

Abstract The germination and establishment of perennial ryegrass and supina bluegrass within a refined wood fiber mat (Ecomat®) placed on plastic sheeting was evaluated using seven mulches and a control with no mulch. Percent turfgrass cover (0–100%) was visually estimated as a measure of seedling density at 7, 14, 21, and 28 days after seeding. Three field experiments were initiated on July 3, 1995, September 29, 1995, and July 5, 1996. The three seeding dates were chosen to show the effects of mulches under optimal and suboptimal growing conditions for cool season turfgrasses. The seven mulches consisted of hydrated fiber mulch, copolymer of sodium acrylamide, crumb rubber, straw, fine grade compost, pelletized fiber mulch, and a native Capac loam soil. Percent turfgrass cover differed among species for the seven mulch treatments and the control, and the three seeding dates. Overall, perennial ryegrass achieved 25% greater cover than supina bluegrass. The straw, pelletized fiber mulch, and hydrated fiber mulch resulted in the greatest turfgrass cover regardless of seeding date. Crumb rubber performed equal to these mulches only during the 29 September 1995 seeding trial. In summary, the use of a particular mulching material will enhance turfgrass cover during seed germination.