Plywood Production Research Articles

Study on preparation and properties of phenol-formaldehyde-chinese fir liquefaction copolymer resin

A new zero-waste and zero-pollution composite adhesive labeled Chinese fir-based adhesive for exterior plywood was synthesized by blending alkaline Chinese fir (Cunninghamia lanceolata) liquid with a small amount of phenol-formaldehyde (PF). The free phenol and free formaldehyde content of the Chinese fir-based adhesive were sharply decreased compared to normal PF resin by more than 50%. The synthetic adhesive show with excellent water resistance and environmental friendliness, which had a 28h boil-dry-boil wet bonding strength of 1,73MPa according to standard JIS K6806-2003 and a formaldehyde emission of 0,045mg/L according to standard JIS A1460-2003. The structural properties and their thermal properties of cured adhesives were evaluated using Fourier transform infrared (FT-IR) and differential scanning calorimetry (DSC). The FT-IR analysis confirmed the expected chemical structure as the Chinese fir liquid reacted with formaldehyde and phenol which occurred at the wavenumbers of 1733, 1698, 1652cm-1 and 1077, 1048 cm-1. Although the DSC results indicated that the Chinese fir-based adhesive's curing need higher temperature than the control PF resin, the higher curing temperature hardly cripple the availability of Chinese fir-based resin in the plywood production.

Physical and mechanical properties of composites based on polypropylene and timber industry waste

AbstractWood polymer composites (WPC) are widely used materials in different industries because of many application, processing and recycling advantages compared to traditional thermoplastic polymer composites containing mineral fillers [1]. However, the commercial success of these materials primarily depends on improvements in moisture performance, and ability to use recycled and waste material as a wood filler. The research regarding WPC is focused on the chemical interaction between dissimilar material components with an aim to provide strong adhesion to the surface of wood filler-polymer matrix [2]. The goal of this paper was to present results of investigations of exploitation properties of composites containing different plywood production industry byproducts and polypropylene. It was shown that modification of all composites with coupling agent maleated polypropylene (MAPP) considerably improve physical mechanical properties (tensile, flexural, impact strength) of WPC. MAPP (5 wt.%) additions also significantly improve water resistance of WPC. SEM investigations confirmed positive action of interfacial modifiers on strengthening of adhesion interaction between components wood and PP matrix that give considerable increase of exploitation properties of the WPC.

Montmorillonite reinforced phenol formaldehyde resin: Preparation, characterization, and application in wood bonding

In this study, the montmorillonite (MMT) reinforced phenol formaldehyde (PF) resin intercalated nano-composite of PF–MMT was prepared from phenol, formaldehyde, and pristine MMT. We then introduced this PF–MMT into the production of plywood from Simao Pine veneers. Matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF), wide-angle X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermal mechanical analysis (TMA), and bonding strength revealed the related structure, curing, and mechanical properties. The thermoplastic PF with a linear structure entered the MMT layers and then formed the network structure after cured. The wet bonding strength and modulus of elasticity (MOE) of plywood were improved significantly. This preparation is simple and easy, and can be applied in the production of wood industry.

The effect of different kinds of nanosilica on practical properties of plywood

The effect of vinyltrimethoxysilane- and γ-aminopropyltriethoxysilane-treated nanosilica and untreated nanosilica particles as fillers on practical properties of urea formaldehyde-bonded plywood was evaluated. Nanosilica used in two different contents (1 and 2 %). The results of FT-IR spectroscopy revealed that both silane coupling agents can well treat the nanosilica particles. The least water absorbtion and thickness swelling observed in the case of boards with 1 % treated nanosilica with vinyltrimethoxysilane, and those with γ-aminopropyltriethoxysilane had the best bending strength and modulus of elasticity. The higher shear strength found for boards with 2 % treated nanosilica by 1 % vinyltrimethoxysilane. Overall, in comparison with the common filler used in plywood production, namely wheat flour, nanofillers had a greater improving effect on the plywood properties. The effect of vinyl silane and amino silane on properties of plywood is different with each other because of their different constructions. The vinyl silane had a better performance than the amino one to improve the physical properties (2 and 24 h water absorption and thickness swelling) and shear strength of the produced boards but the latter showed a higher increasing impact on the modulus of elasticity and rupture. The results showed that 1 % nanosilica had proper enough effect on properties of plywood panels and even in some cases had better effect than 2 % nanosilica content.

QUALITY OF PLYWOODS OBTAINED FROM Melia azedarach COMBINED WITH Pinus taeda, PRODUCED WITH UREA-FORMALDEHYDE AND PHENOL-FORMALDEHYDE RESINS

AbstractThis study was developed to evaluate the quality of plywood produced from Melia azedarach in combination with Pinus taeda, glued with urea-formaldehyde resin (UF) and phenol formaldehyde (PF). Panels were produced using five veneers of Melia azedarach only, five veneers of Pinus taeda and also with faces made of Melia azedarach and core with Pinus taeda. The panels were evaluated by glue line shear tests and by static bending in parallel and perpendicular directions. The higher contents of extractives in Melia azedarach wood did not reduce the glue line shear strength between the layers. For both UF and PF glues, panels produced with veneers of Melia azedarach showed better results on static bending and glue line shear tests. The results indicate great potential of Melia azedarach wood in plywood production, both for internal use (UF), and for external use (PF).Keywords: Cinamomo; wood veneer; glue line. ResumoQualidade de painéis compensados de Melia azedarach em combinação com Pinus taeda produzidos com resina uréia-formaldeído e fenol-formaldeído. O objetivo deste trabalho foi avaliar a qualidade de painéis compensados de Melia azedarach em combinação com Pinus taeda, produzidos com resina ureia-formaldeído (UF) e fenol-formaldeído (FF). Foram produzidos painéis com todas as cinco lâminas de Melia azedarach e de Pinus taeda, e capas de Melia azedarach e miolo de Pinus taeda. Os painéis foram avaliados por meio de ensaios de cisalhamento da linha de cola e flexão estática paralela e perpendicular. Maiores teores de extrativos presentes na madeira de Melia azedarach não prejudicaram a resistência da linha de cola entre as lâminas. Tanto para a colagem uréica, quanto para a fenólica, os painéis produzidos com lâminas de Melia azedarach apresentaram melhores resultados nos ensaios de flexão estática e de cisalhamento da linha de cola. Os resultados obtidos indicam grande potencial da madeira de Melia azedarach para produção de painéis compensados, tanto para uso interior (UF), quanto para uso exterior (FF).Palavras-chave: Cinamomo; lâminas de madeira; linha de cola.

Energy wood resources availability and delivery cost in Northwest Russia

Availability of solid by-products from wood harvesting and mechanical wood processing was estimated as sources for energy production based on recent actual harvesting, sawmill, and plywood production in Northwest Russia at 30 million m3. Nearly 70% of the energy wood, 20 million m3, was from harvesting, consisting of non-industrial round wood, unused branches and tops, defective wood resulting from logging, and spruce stumps removed after final felling. Over 30%, 10 million m3, of the available volume was from sawmills and plywood mills, i.e. wood chips, sawdust, and bark. Due to current low utilization of energy wood for bioenergy in Northwest Russia, delivery cost of energy wood to the potential border-crossing points in Finland was analyzed for three means of transport: railways, roadways, and waterways. Nearly 28 million m3 of the energy wood could be transported by railways and 2 million m3 by roadways and waterways. The costs were lowest by roadways from the nearby border areas (10–15 €/m3 for wood processing by-products and 16–22 €/m3 for forest chips). The costs by railways varied from 12 to 27 €/m3 on shorter distances to 47–58 €/m3 on longer distances. Waterway transportation was the most expensive, about 28–48 €/m3. It should be emphasized that we have estimated availability and delivery costs of energy wood, not prices which are defined by the market based on supply and demand.

Quality Assessment in Industrial Production of Plywood by Stiffness and Strength Properties in Bending

This research aimed to investigate, by means of the strength (MOR) and stiffness (MOE) properties in bending, the homogeneity in the manufacture of ply wood (Pinus sp wood and phenolic resin) produced by an industry located in the state of Parana (PR - Brazil). The factors and levels investigated in this study were the choice of panels (A, B, C and D), the extraction position of the specimens (Center; Side) and fiber orientation (Parallel, Perpendicular), providing a fu ll factorial design of 4 1 2 2 type, with 16 different treatments. On the panel, were extracted 20 specimens (500×75×18mm) for bending tests. ANOVA results showed that the choice of panel and fiber orientation was significant in the properties of strength and stiffness in bending, this is not occurring with the ext raction position of the specimens. The MOR and MOE of the specimens obtained in the parallel d irection were 87% and 141% h igher than the MOR and M OE of the specimens evaluated in the perpendicular direction, respectively, and with respect to non-equivalence found between the mechanical properties by the choice of the panel, for results with greater reliability it is necessary the development of new research with a significantly higher number o f ply wood.

Some technological properties of wood–styrofoam composite panels

Synthetic resins are widely used in wood based composites manufacturing. Besides their many advantages, most of them contain formaldehyde and a chemical agents that cause environmental problems. Styrofoam known as expanded polystyrene, is used all over the world for various purposes including thermal insulation, packing, coffee cups, fabrication of car parts etc. This study investigated the evaluation possibilities of styrofoam wastes in plywood production as a bonding material. Pine (Pinus pinea) and poplar (Populus deltoides I-77/51) veneers were used to produce wood–styrofoam composite (WSC) and traditional plywood. Urea-formaldehyde adhesive was used as bonding material for traditional plywood panels. Two different types of styrofoam having high density (25kg/m3) and low density (10kg/m3) were used as binder in the manufacturing of WSC panels. Bonding and bending strength, modulus of elasticity, density and thermal conductivity of plywood and WSC panels were investigated. Experimental results showed that mechanical properties of panels manufactured with low density styrofoam type were higher than those of panels manufactured with high density styrofoam type. The lowest thermal conductivity among the all panels was found for poplar panels manufactured with high density styrofoam.

Reduction of formaldehyde emission from plywood

The aim of this work is to evaluate performances of tannin-based resins designed as adhesive in the plywood production. For this purpose, a part of phenol formaldehyde (PF) and melamine formaldehyde (MF) in the classic adhesive formulation was replaced by tannin. The physical properties of the formulated resins (rheological characterization, etc.) were measured. In order to analyze the mechanical performance of tannin-based resins, plywood panels were produced and the mechanical properties including tensile strength wood failure and three-point bending strength were investigated. The performance of these panels is comparable to those of plywood panels made by commercial PF and MF. The results showed that the plywood panels bonded with tannin–PF (PFT) and tannin–MF (MFT) resins exhibited better mechanical properties in comparison to the plywood panels made of commercials PF and MF. The introduction of small properties of tannin in PF and MF resins contribute to the improvement of the water performance of these adhesives. The formaldehyde emission levels obtained from panels bonded with tannin-based resins were lower than those obtained from panels bonded with control PF and MF. Although there are no actual reaction at all between PF, MF, and tannin, addition of tannin significantly improves the water resistance of PF and MF resins. This is a novel finding that manifests the possibility of replacing a convention PF and MF resins by tannin. Modified adhesive is one of the goals in the plywood production without changing any of their production conditions with improvement to their overall properties.

Development a new method for pilot scale production of high grade oil palm plywood: Effect of resin content on the mechanical properties, bonding quality and formaldehyde emission of palm plywood

The main objectives of this research were to investigate the formaldehyde emission, some mechanical properties and bonding quality of oil palm trunk (OPT) plywood treated with low molecular weight phenol–formaldehyde (LmwPF), as affected by resin concentration. The mechanical properties are affected by different of amount resin solid contents used. The OPT veneer were treated at either 40%, 32%, 23% or 15% of resin concentration and 12mm thickness of 3-ply plywood panel were manufactured for each group. In this study the formaldehyde emission, modulus of rupture (MOR), modulus of elasticity (MOE) and bonding quality (shear strength) of OPT plywood were determined. The results revealed that the resin-treatment method was tend to significantly improved the mechanical properties of the OPT plywood panel in which increased solid absorption gives bettermechanical properties. Apparently, high mechanical properties were obtained for panel manufacturer from veneer treated with 32% and 40% resin content. The resin-treated OPT plywood provided superior mechanical strength with improvements at least 202% MOE and 159% MOR compared to commercial OPT plywood. Whereas, mechanical properties of the resin-treated OPT plywood were drastically decrease with increasing the water substitution. Formaldehyde emission content of OPT panels decreased upon reduction of resin content into treatment process and were significant at resin concentration. The resin-treated OPT panels at 32% solid content provided a reasonable amount of free formaldehyde (0.359mg/L) which attained F∗∗∗∗ according to Japanese Agriculture Standard (JAS). The shear strength of resin-treated OPT plywood panel with 32% and 40% resin content achieved minimum requirements according to the standard European Norms EN 314-1 and EN 314-2 for the interior and exterior application.

Emergence and rise of eucalypt veneer production in China

SUMMARY China's plywood production grew rapidly over the past 15 years from around 9 Mm3 yr-1 in the mid 1990s to over 55 M m3 yr-1 by 2011. Associated with this has been a proliferation of small-scale eucalypt veneer mills processing young (≤ 5 yrs) small diameter logs (mostly ≤ 12 cm small end diameter); by 2011 there were over 5000 such mills in China with a collective capacity to process well over 15.0 M m3 yr-1 of logs. We review key characteristics of this eucalypt veneer industry with special focus on three key regions for eucalypt veneer production in China. Factors that have spurred and facilitated the rapid growth of this industry are reviewed along with future challenges likely to emerge for China's eucalypt veneer industry.

Substitution of formaldehyde based adhesives with soy based adhesives in production of low formaldehyde emission wood based panels. Part 1 – Plywood

This paper describes a study on the use of a soy adhesive system as a substitute for melamine urea formaldehyde adhesive in plywood production. Results are presented on bonding quality and formaldehyde emission of laboratory scale panels bonded with different mixes of formaldehyde based resins substituted with a soy adhesive system. This study demonstrates that the addition of soy adhesive system significantly reduces formaldehyde release from plywood. Based on the results, the optimum amount of the soy addition depends on the requirements of use of the final product and formaldehyde emission. The highest substitution level recommended is 25% for the production of panels with very low formaldehyde emission for use in class 2 or 3 conditions, whereas up to 75% substitution would seem possible for class 1 panels.

Manufacture of Environmentally Friendly Plywood Bonded with Plastic Film

Abstract The main objective of this study was to evaluate the feasibility of using unmodified plastic film as a novel wood adhesive in the plywood production, which is done to eliminate formaldehyde release during plywood production and use. The bondability of plastic film was determined by testing the shear strength of plywood. In addition, physical–mechanical properties, including thickness swelling, water absorption, modulus of elasticity, and modulus of rupture under the optimal pressing conditions, were also considered. Results showed that the plywood could meet the requirements for Grade 2 plywood according to Chinese National Standard (GB/T 17657‐1999) and that the highest strength was obtained under hot-pressing conditions (pressure, 0.7 MPa; temperature, 160°C; time, 1 min·mm−1; and film dosage of two layers), which was comparable to that of commercial urea-formaldehyde plywood as determined by Liu (Master's thesis, Zhejiang Agric. and Forestry Univ., Hangzhou, China, 2010). Pressing temperature had a notable effect on adhesive penetration and bonded joints formed. Mechanical interlock, as observed by scanning electron microscopy, formed between nonpolar plastic film and porous poplar veneer.

Development a new method for pilot scale production of high grade oil palm plywood: Effect of hot-pressing time

The main objective in this study were to investigate the physical properties, mechanical properties and bonding qualities of oil palm stem (OPS) plywood pre-preg using low molecular weight phenol–formaldehyde (LmwPF). The properties evaluated were physical properties (resin uptake, weight percent gain), mechanical properties (bending strength) and bonding qualities (dry test, WPB test). The results showed that, the physical properties of OPS plywood were significant at resin concentration and veneer moisture content. Moreover, the mechanical properties and bonding performance of the pre-preg OPS plywood were influenced by the pressing time. The high grade OPS plywood with improved at least 227% MOR and 348% MOE compared to commercial OPS plywood, with greater in MOR (31%) and MOE (12%) higher compared than the commercial tropical mix light hardwood (MLHW) plywood. All the shear strength of pre-preg OPS plywood panel were achieved with their minimum requirements and satisfied all the specific testing based on the standard European Norms EN 314-1 and EN 314-2 for the interior and exterior application purposes. The output of this pilot scale study proved that high performance OPS plywood could produced through pre-preg enhancement method in the current plywood mills in which provides broader area of applications compared with conventional OPS plywood. For instant, the pre-preg OPS plywood which is suitable for structural application, concrete formwork, heavy duty interior structuring board, load bearing plywood, marine grade plywood, was obtained, thus consequently increases the price of OPS plywood panels.

Discrepancies between targets and achievements in industrial forest production and export in Tanzania

It is important to revisit our plans and compare what was ideally targeted against what was actually achieved in implementation. In comparing the achievements with targets, strengths or weaknesses of established strategies can be accepted or corrections implemented since a plan also outlines some strategies for achieving the targets set. In this study, achievements in production and export of industrial forest products, i.e., sawn wood, plywood, chipboard and fibreboard, paper and paperboard and industrial round wood, are compared against targeted figures for 1996 for Tanzania. Discrepancies were obtained by subtracting targeted from achieved values and expressed both as absolute and relative differences in terms of the targeted values, with a negative sign for production where achievements were less than targets and a positive sign when achievements were higher than targets. Values achieved ranged from 4%–100% of the targeted values, depending on the product, and were only higher than the targeted value for industrial round wood. Possible causes of the discrepancies are inefficiency of parastatal companies, low private investment, sub-maximal industrial operation and plant inefficiencies. Discrepancies could also result from unrealistic data used in planning due to difficulty in data availability and poor intra- and inter-sectoral coordination. The implications of these discrepancies are low contributions of the wood-based industry to the national economy, increased import substitution of wood-based products, increased socio-economic and environmental degradation and decreased integrity in planning and policy making.

Constructional Bamboo Plywood Process Control and Production Process

Focusing on the problems of the bamboo plywood existing in the construction field, we have proposed an optimal process for the building bamboo plywood through controlling the preparation process of the bamboo plywood. In our work, moso bamboo was selected as the objective and then a variety of performances of the bamboo plywood were tested with the heat-up-heat-down process. Experiments show that in the same conditions of MC 10%, RC 7%-8%, the best optimum processes of 12mm thick constructional bamboo plywood is 15min pressing time, the pressing temperature between 155°C to 160°C and the sheet density of 0.85 g/cm3. The optimal process to make the performance of bamboo plywood substantially exceeded the European standard the OSB/4 levels. It can provide practical application of engineering and production design with reference value and theoretical basis for the bamboo plywood.

Structural Performance of Chinese Larch Plywood

China has the largest plywood production in the world. With the fast development of timber construction in China, plywood has been used as an important structural material for sheathing. It is needed to evaluate some performances for structural use, such as uniform load test. Plywood of different thickness is manufactured according to independent developed technology on a production line. The uniform load capacity was evaluated for wall sheathing. The results showed that those two types met requirements on structural performances of wall sheathings of PS2. It was suggested that the unnecessary high performance should be intentionally lowered by veneer combination of larch or other soft species.

Development of soy-based adhesives for the manufacture of wood composite products

Abstract Soy-based resins have recently attracted great attention as adhesives in the wood composite industry. This article is focusing on hydrolysis and modification of soy protein concentrates to formulate soy-based resins for wood composites. The soy-based resins have been evaluated in terms of bondability on wood substrates and bonding performance in plywood products. The performance of plywood was found to meet the relevant CSA standard (Canadian Standard Association) requirements under both of dry and wet conditions, if the soy-based resins were obtained from low hydrolyzed soy flour. Hydrolysis is an effective and efficient tool for reducing the viscosity of soy resins. However, hydrolysis also reduces the bond strength of soy-based resins as hydrolysis cleaves the macromolecules of soy proteins into smaller molecules. Modified soy-based resins have a certain potential for production of interior- and exterior-used plywood.

Determining Stocks and Flows of Structural Wood Products in Single Family Homes in the United States between 1950 and 2010

Abstract The stocks and flows of six major structural wood products (SWPs)—lumber, plywood, oriented strand board [OSB], glue laminated timber, I-joists, and laminated veneer lumber (LVL)—in US single family homes were modeled from 1950 to 2010. The consumption of these products in US single family homes and their emissions as construction and demolition wastes were estimated. The net consumption of SWPs decreased from 119 kg/m2 constructed in 1986 to 82 kg/m2 in 2010. Softwood lumber was consistently the predominant SWP, but its usage intensity decreased from 95 kg/m2 in 1986 to 52 kg/m2 in 2010. Since the 1980s, modern SWPs, such as I-joists, LVL, and OSB, have replaced lumber and plywood products. The needs of the US single family housing industry have been met by a smaller mass of SWPs per unit area constructed. The mass of SWP present in construction wastes was influenced strongly by building cycles. Production of construction waste peaked in 2005, when 3.31 million tonnes of SWPs were produced by 1.72 million single family housing starts. It diminished to 0.874 million tonnes of SWPs as the housing starts fell to 445,000 in 2009. In contrast, the mass of demolition wastes produced was affected substantially by the number of houses in the stock and their half-lives. Approximately 4.5 million tonnes of SWP demolition waste were produced in 2010, and in the same year, the stock of SWPs in US single family homes reached 1,220 million tonnes.

Study on Structural Plywood Production Technology from Eucalyptus/poplar

With the rapid development of wooden structure buildings in China, the demand for structural plywood enlarges significantly. Eucalyptus and poplar plantation is a very wide area of growth in china, therefore, there is practical significance to use eucalyptus and poplar plantation to produce wooden structural plywood. This study uses orthogonal test on pressing temperature, pressing time, pressing pressure, veneer glue spread - four factors influence the bond strength of structural plywood from Eucalyptus/poplar, and has obtained the superior technology. The results show that hot pressing temperature, pressing time, pressing pressure, veneer glue spread –four factors affect the bond strength of the structure plywood significantly, but the difference among the three veneer glue spread levels is not significantly. The better production technology is hot pressing temperature 135 °C, pressing time 24 min, pressing pressure 1.2 Mpa, veneer glue spread 320 g/m2.