Wood, Plastics, and Composites

Fungal infection to wood and panel product is a major economic concern for the building industry as it causes heavy losses of wood used in the construction. It is imperative to take the necessary steps to preserve the wood and the wood products. Due to growing concerns about the adverse effects of chemical preservatives on human health as well as environmental concerns had made the consumer look for alternatives. Hence an ideal compound for wood protection for interior applications which is non-toxic and able to provide long-term efficacy is increasingly being sought. As result, many plants are screened and their extractives were getting evaluated for their ability to inhibit fungal infection on wood. However, there is a lack of literature on the utilization of these bio based preservatives as the fungal inhibitor in wood composite panels. A study in this line is very important as challenges involved with of bio-based wood preservative for panel wood are totally different. Botanical preservative which is highly effective in wood may not be suitable for the panel wood products. Some modifications and incorporations are vital to use this bio-based preservative in the wood composite material. The objective of this paper is to investigate the fungal inhibitory effects of some natural plant extracts mixture, on wood panels and differences in their performances along with an obstacle faced in case of panel woods. For the purpose, extract of Lantana camara L., Ricinus communis L. Catharanthus roseus (L.) G. were prepared using water and petroleum ether as solvents by standard procedure. Amount of extractives obtained were quantified for each plant species. Extractives formed were range from 11-68-14.33 for different plant species. Extracts obtained from different plant were mixed to form a synergetic preservative and same was mixed in PF and UF resin at different concentrations (1%, 1.5%, 2%, 5% and 10%) and plywood samples were prepared using rubber wood veneers. Control panels were also prepared with PF and UF resins without extractives. From these panels experimental blocks were prepared and introduced in Kolle flask, containing test fungi Polyporous meliae and Trametes versicolor along with the control samples. Whole experimental setup was kept at room temperature (25±5o C) with 60-70% relative humidity. After the completion of an experiment, samples were removed from the Kolle flask and myceliums adhering to test samples were cleaned by taking care not to remove the splinters of the samples. Blocks were dried in an oven and final weight was taken. Mean percentage weight loss was calculated, which varied from 8-25% for different test samples. Result revealed that, Minimal fungal inhibitory effect was seen even at 1% concentration and as concentration increased resistance also increased. But at higher concentrations of extractives in glue line negatively affected the important physical and mechanical properties of panels. Hence it is important to determine an optimal extractive concentration to achieve the best possible result as the bio based preservative that too without affecting the bonding strength of the plywood. Thus we can conclude that incorporating with slight modifications effective eco-friendly wood preservatives can be prepared by utilizing these plant extractives. Keywords: Fungal wood decay, Bio-control, Plant extracts, PF and UF resins

The pioneers and settlers of America found forests which seemed to go on forever. The forests provided low cost building materials and shelter in those times and continued to do so on through the industrial revolution and up to the present day. Thanks to the foresight of a few foresters and politicians in the 1900 era, vast forestlands across the country were set aside on a multiple‐use basis; an important precept of which was to provide a sustained and renewable timber harvest to bolster the nation's need for wood and wood products. Properly managed, these lands and those of private landowners can supply these needs indefinitely. The wood resources also must be utilized effectively, so that the various wood products and papers will continue to be available in the necessary quantities at reasonable cost. Practices which better utilize smaller trees and wood residues, which were formerly wasted, to create useful composite materials are an extremely important segment of this entire system. The wood composites industries in the United States have grown steadily for approximately 100 years. Product development has grown into production of a family of composites which can fill virtually every niche in the construction field, in furniture and cabinetry, as well as in numerous other applications for these products. The industry began with hardwood plywoods and has progressed through softwood plywood, insulation boards, hardboards, particleboards, medium‐density fiberboards, waferboards and oriented strand boards, and finally structural composite lumber. From their beginnings, these products have filled needs in applications to which they were well suited. Some later arrivals have competed with earlier products and in some cases have partially or totally displaced them because they were more suited to the application or more economical, or sometimes both. Whereas it may not yet be totally practical, it is possible to build and furnish entire structures such as homes and businesses using only products from the wood composites group. As the United States begins to rely more heavily on use of smaller trees for construction materials, the products from the composite industries form a most important portion of the country's needs for these products. As an example of the size of these industries, in 1994 wood‐based composite products made with small logs, wood veneer, chips, shavings, and sawdust were produced at a level of 39.1 × 10 6 m 3 . Primarily owing to availability of economical wood products and building practices which utilize these products efficiently in warm, comfortable, and affordable housing, the United States is possibly the best housed nation on Earth.

Technical natural fibre semi-finished products are mainly used in lightweight automotive components as random fiber mats which are often combined with petrochemical matrix resins for large series production process. However, random fiber arrangement and limited fiber length restrain the complete utilization of the material-inherent strength reserves of natural fibers. With high-levels of petroleum-based plastics (about 20-50 wt -%) in the structure, these applications have a clear potential in terms of eco-friendliness and sustainability. The development of new fully bio-based composites and efficient manufacturing methods suitable for series processing is the purpose of the current sub-project C4 “Flexible textile / plastics processes with renewable raw materials” in the framework of the Excellence Cluster MERGE EXC 1075, funded by DFG (Deutsche Forschungsgemeinschaft). A high-efficiency in terms of mass-production, reproducibility and flexibility requires the performance of successive steps in the manufacture of semi-finished and final products. The appropriate process line comprises the steps of the preparation of the thermoplastic matrix sheets (such as from Bio-polyethylene or Bio-polyamide) and a specific chemical modification of the reinforcing materials (wood veneer and unidirectional flax fibers) on the concept of a discontinuous or continuous production of unidirectional reinforced Natural Fibre Composites (NFC) prepregs. Moreover, the shaping of hybrid lightweight structures from NFC prepregs makes possible the incorporation of these innovative technologies into new concepts and potential applications in several fields such as automotive industry or sport equipment. The mechanical properties profile of the flax - natural unidirectional sheet for fibre reinforced bioplastics has been here studied in detail with press-engineered samples and has confirmed their high application potential as an alternative to glass fiber-reinforced composite sheets.

Brazil stands out internationally in the production and commercialization of wood products. Although the external and internal demand for these products is met by the Brazilian forestry sector, challenges related to the internal management of lignocellulosic waste are evident, as the country has structural difficulties in the sector of solid waste management. Therefore, the objective was to comparatively analyze the performance of the most abundant lignocellulosic materials in the Brazilian market, regarding energy recovery at the end of their life cycles. Pine wood treated with chromed copper arsenate (CCA), untreated pine wood, eucalypt wood treated with CCA, untreated eucalypt wood, uncoated medium density fiberboard panel (MDF), and MDF panel with melamine coating were sampled. The characterization included thermogravimetric analysis (TGA), scanning electron microscopy (SEM) with energy-dispersive x-ray spectroscopy (EDXA), and elementary analysis (EA). The presence of the CCA salts and the melamine coating reduced the energy potential of the biomass, altering the burning behavior and significantly increasing the amount of generated ashes. They also caused an increase in the concentrations of copper (Cu), chromium (Cr), arsenic (As), and cadmium (Cd) in the wood ashes as well as lead (Pb) and chromium in the panel ashes.

The efficacy of antimicrobial treatments to eliminate or control biological growth in the indoor environment can easily be tested on non-porous surfaces. However, the testing of antimicrobial efficacy on porous surfaces, such as those found in the indoor environment (i.e., gypsum board, heating, ventilating and air-conditioning duct-liner insulation, and wood products) can be more complicated and prone to incorrect conclusions regarding residual organisms and non-viable allergens. Research to control biological growth using three separate antimicrobial encapsulants on contaminated duct-liner insulation has been performed in both field and laboratory testing. The results indicate differences in antimicrobial efficacy for the period of testing.

Harvested wood products (HWPs) store a significant amount of carbon, and their lifetime extension and appropriate waste management, recycling, and reuse can contribute remarkably to the achievement of climate goals. In this study, we examined the carbon storage and CO2 and CH4 emissions under different scenarios of 200,000 m3 particleboard manufactured in 2020 by a hypothetical manufacturer. The scope of our investigation was to model the effects of a changing product lifetime, recycling rates and waste management practices on the duration of the carbon storage in wood panels and on their emission patterns. The aim of the investigation was to identify the most climate-friendly practices and find the combination of measures related to HWP production and waste management with the highest climate mitigation effect. We used the newly developed HWP-RIAL (recycling, incineration and landfill) model for the projections, which is a combination of two IPCC models parametrized for Hungarian circumstances and supplemented with a self-developed recycling and waste-route-selection submodule. The model runs covered the period 2020–2130. According to the results, the combined scenario with bundled mitigation activities had the largest mitigation potential in the modelled period, resulting in 32% emission reduction by 2050 as compared to the business-as-usual scenario. Amongst individual mitigation activities, increased recycling rates had the largest mitigation effect. The lifetime extension of particleboard can be a complementary measure to support climate mitigation efforts, along with the concept of cascade use and that of circular bioeconomy. Results showed that landfilled wood waste is a significant source of CH4 emissions on the long term; thus, incineration of wood waste is preferable to landfilling.

Quercus robur wood veneer with pronounced natural color uniformity and stability by regulating the content of phenolic extractives

<p>the effects of refining and alkaline chemicals on potential of recycling bleached chemical pulp of bagasse were investigated in this study. Recycling was done until three times. Handsheet properties such as, apparent density, light scattering coefficient, tear index, burst index, breaking length, and fold number according to TAPPI standard were measured. Water retention value also was used to considering the treatments during recycling. Refining enhanced the strength of recycled pulp by increasing fiber flexibility and swelling ability, whereas by applying chemical treatment didn't observe any improvement. The morphology of recycled fiber was considered with scanning electron microscopy (SEM).</p>

Because of the lack of data on the thermal expansion of natural solid wood and many wood products, such as plywood, impreg, compreg, and many others, studies were conducted at the Forest Products Laboratory in an effort to obtain such data. The coefficients of linear thermal expansion, called α were measured on a wide variety of wood materials in three structural directions. General formulas were developed which permit calculation of the coefficients of linear thermal expansion in any grain direction of the specimen from the original and final specific gravities, the percentage by weight of resin and glue present, the percentage of cross-banding, and the slope of grain relative to any three axes of reference.

Addressing disturbance risk to mountain forest ecosystem services

RETRACTED: An assessment of volatile organic compounds pollutant emissions from wood materials: A review

The authors acknowledge the considerable cooperation and active participation in this study by many individuals of research work

The possibility of obtaining white oxide coatings on aluminum was investigated. Until now, an industrial method of producing white and opaque oxide coatings on aluminum by electrochemical method has not been worked out. In some industries there is a need for a white surface finish of aluminum products. Two methods of obtaining white coatings and three sealing methods have been tested during the work. The quality of coatings has been tested according to standard QUALANOD tests, decorative values were additionally evaluated. The obtained coatings have been compared with transparent oxide coatings on aluminum, which have been obtained by conventional methods.

Composite wood materials, also known as engineered wood products, are fabricated from wood veneer, particles, strands, flakes, or fibers that are bonded together with synthetic or renewable, biobased adhesive systems and designed to meet a wide range of structural and non-structural applications [...]

Success of a deadwood enrichment strategy in production forests depends on stand type and management intensity