scholarly journals Properties of Thermoplastic-Bonded Plywood: Effects of the Wood Species and Types of the Thermoplastic Films

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2582
Author(s):  
Pavlo Bekhta ◽  
Marcus Müller ◽  
Ilona Hunko
Keyword(s):  
Wood Species ◽  
Bonding Strength ◽  
Bending Strength ◽  
Low Cost ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Environmentally Friendly ◽  
Significant Difference ◽  
Class 1 ◽  
Dry Conditions

There are a lack of proper adhesives that meet the wood industry requirements of being environmentally friendly, low cost, and easy to use; thus, the application of thermoplastic polymers, especially films, is promising. This work expands our knowledge about the possibility of using thermoplastic films for the production of environmentally friendly plywood. The effects of the adhesives type and wood species on the properties of plastic film bonded plywood were studied. Sliced veneers of two hardwoods (birch and beech) and one softwood (spruce) were used in the experiments. Three types of thermoplastic films—low-density polyethylene (LDPE), co-polyamide (CoPA), and co-polyester (CoPE)—were used as an adhesive for bonding plywood samples. Melamine–urea–formaldehyde (MUF) resin was used as a reference. The influence of the type of adhesive and wood species as well as their interaction on the properties of plywood was significant. The lowest bonding strength demonstrated plywood samples bonded by LDPE, and the highest bonding strength in the samples was shown in those bonded by CoPA. A significant difference was found between softwoods and hardwoods in terms of their influence on the physical and mechanical properties of plywood samples. From the obtained data, it follows that softwoods provide much lower values of bending strength (MOR), modulus of elasticity (MOE), and bonding strength than hardwoods. The obtained bonding strength values of plastic-bonded plywood panels ranged from 1.18 to 2.51 MPa and met the European standard EN 314-2 for Class 1 (dry conditions) plywood.

scholarly journals The Effect of Veneer Densification Temperature and Wood Species on the Plywood Properties Made from Alternate Layers of Densified and Non-Densified Veneers

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 700 ◽  
Author(s):  
Emilia-Adela Salca ◽  
Pavlo Bekhta ◽  
Yaroslav Seblii
Keyword(s):  
Shear Strength ◽  
Wood Species ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Thermal Compression ◽  
Black Alder ◽  
Densification Temperature ◽  
Class 1 ◽  
Bonding Properties ◽  
Dry Conditions

In this study the properties of plywood manufactured from densified and non-densified veneer sheets and alternate layers of such veneers with and without densification using low amount of adhesive as a function of densification temperature and wood species were investigated. The plywood panels were made from rotary-cut birch and black alder veneers using urea-formaldehyde (UF) adhesive. Veneer sheets with thickness of 1.5 mm were subjected to the thermal-compression at three different temperatures while keeping constant the pressure during a same time span. Five-layers plywood panels were produced using a constant hot-pressing schedule using different amounts of glue spread as a function of the plywood type; such as plywood made from non-densified (80 g/m2) and densified (60 g/m2) veneers only; and combination of them (70 g/m2). The bending strength (MOR) and the modulus of elasticity (MOE) along with the shear strength of the plywood samples for bonding class 1 (dry conditions) have been determined. As expected bending strength of the plywood samples increased with the increasing in density. The increase of veneer densification temperature resulted in a gradually decrease of MOR; MOE and shear strength values for the plywood panels made of densified veneers and mixed panels of both species. The temperature of 150 °C for veneer densification seemed to be enough to achieve enhanced bending and bonding properties. All plywood panels in this study were manufactured using reduced glue consumption and they presented satisfactory properties performance for indoor applications.

scholarly journals Sifat Kayu Lapis yang Dibuat dari Lima Jenis Kayu Asal Riau

2020 ◽  
Vol 25 (4) ◽  
pp. 657-663
Author(s):  
Achmad Supriadi ◽  
Deazy Rachmi Trisatya ◽  
Ignasia Maria Sulastiningsih
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Wood Species ◽  
Bonding Strength ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
National Standard ◽  
Randomized Design ◽  
Completely Randomized Design

The objective of this study was to determine the physical and mechanical properties of plywood made of punak (Tetramerista glabra Miq.), meranti bunga (Shorea teysmanniana Dyer ex Brandis), mempisang (Alphonsea spp.), suntai (Palaqium burckii H.J.L.), and pasak linggo (Aglaia argentea Blume). Liquid urea formaldehyde (UF) was used as an adhesive. Data analysis was carried out using a completely randomized design. Results showed that the moisture content and density of plywood produced in this study were around 10.4-10.95% and 0.65 to 0.93 g/cm3, respectively. The modulus of elasticity (MOE) and modulus of rupture (MOR) of plywood produced were between 63.371-123.548 kg/cm2 and 517-1.052 kg/cm2, respectively. It was also found that the tensile strength and bonding strength of the plywood produced were 461.6-1.095 kg/cm2 and 18.97-31.79 kg/cm2, respectively. It was recorded that moisture content and the bonding strength of the plywood produced met the Indonesian National Standard of Plywood. Among others, plywood produced from pasak linggo showed a superior quality. Referring to statistical analysis, it was confirmed that physical and mechanical properties of plywood were significantly affected by wood species, except moisture content. Keywords: mechanical properties, physical properties, plywood, Riau wood species

scholarly journals Effect of Veneer-Drying Temperature on Selected Properties and Formaldehyde Emission of Birch Plywood

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 593 ◽  
Author(s):  
Pavlo Bekhta ◽  
Ján Sedliačik ◽  
Nataliya Bekhta
Keyword(s):  
Modulus Of Elasticity ◽  
Bonding Strength ◽  
Elevated Temperatures ◽  
Bending Strength ◽  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Formaldehyde Emission ◽  
Bonding Quality ◽  
Mean Values

In this study, the effect of the veneer-drying process at elevated temperatures on selected properties and formaldehyde emission of plywood panels was determined. We assume that during the veneer drying at high temperatures, more formaldehyde is released from it, and therefore, a lower formaldehyde emission can be expected from the finished plywood. Prior to bonding, birch veneers were dried at 160 °C (control) and 185 °C in an industrial veneer steam dryer (SD) and at 180 °C, 240 °C and 280 °C in an industrial veneer gas dryer (GD). Two types of adhesives were used: urea–formaldehyde (UF) and phenol–formaldehyde (PF) resins. Bonding quality, bending strength and modulus of elasticity in bending, water absorption and thickness swelling of plywood samples were determined. The formaldehyde emission level of samples was also measured. It was concluded from the study that the effects of veneer-drying temperatures on the bonding strength and physical and mechanical properties of plywood panels were significant. Veneer-drying temperatures of 185 °C/SD, 180 °C/GD and 240 °C/GD negatively affected the bending strength and the modulus of elasticity along and across the fibres for both UF and PF plywood samples. Bonding strength mean values obtained from all test panels were above the required value (1.0 MPa) indicated in EN 314-2 standard. The lowest formaldehyde emissions for the UF and PF plywood samples were observed in the samples from veneer dried in a steam dryer at 185 °C/SD.

scholarly journals Evaluation of properties of graded density fiberboard produced from wood residues (sawdust and corrugated paper)

2020 ◽  
Vol 26 (2) ◽  
Author(s):  
Oghenekevwe Abigail Ohwo ◽  
Ighoyivwi Onakpoma ◽  
Eduvie Okoromaraye
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Raw Material ◽  
Thickness Swelling ◽  
Waste Streams ◽  
Wood Residues ◽  
Significant Difference ◽  
Corrugated Paper

Reuse of materials from waste streams is pertinent to achieving sustainable forest production. The enormous wood residues generated at sawmill and the disposal of wood based products poses threat not only to sustenance of the forest resources but also has negative adverse effect on the environment. Limitation exists in the utilization of wood residues as raw material for panel board production in developing countries. This study examined the physical and mechanical properties of graded density fiberboards produced from varying mixture of sawdust and corrugated paper (pulp) at Forestry Research Institute of Nigeria (FRIN) in 2019. A 2x9 factorial experiment in one way analysis of variance was used to test for significant difference between the factors (density and mixing ratio) considered. The result shows that densities of all boards produced varied with mixing proportions. The densities increased with increasing content of corrugated paper. Boards produced at 0.45 g/cm3 showed higher density (0.648 g/cm3), bending strength (MOR) (1.47 N/mm2) and less water absorption (118.69 %) than those produced at 0.65 g/cm3 having values of 0.58 g/cm3, 1.32 N/mm2 and 153.67 %  respectively. However boards produced at 0.65 g/cm3 had higher elasticity in bending (MOE) (209.19 N/mm2) and less thickness swelling (6.29 %) than those produced at 0.45 g/cm3 having values of 74.87 N/mm2 and 10.88% respectively. Panel G (20:60:20), E (30:50:20) and I (10:70:20) of sawdust: corrugated paper: urea formaldehyde respectively showed superior features in physical and mechanical properties with panel I been the best mixture. Conclusively, wood residues (sawdust and corrugated paper) are suitable raw material for fiberboard production.

scholarly journals Eco-Friendly, High-Density Fiberboards Bonded with Urea-Formaldehyde and Ammonium Lignosulfonate

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 220
Author(s):  
Petar Antov ◽  
Viktor Savov ◽  
Ľuboš Krišťák ◽  
Roman Réh ◽  
George I. Mantanis
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
High Density ◽  
Thickness Swelling ◽  
Formaldehyde Content ◽  
Uf Resin ◽  
Natural Wood ◽  
European Standards

The potential of producing eco-friendly, formaldehyde-free, high-density fiberboard (HDF) panels from hardwood fibers bonded with urea-formaldehyde (UF) resin and a novel ammonium lignosulfonate (ALS) is investigated in this paper. HDF panels were fabricated in the laboratory by applying a very low UF gluing factor (3%) and ALS content varying from 6% to 10% (based on the dry fibers). The physical and mechanical properties of the fiberboards, such as water absorption (WA), thickness swelling (TS), modulus of elasticity (MOE), bending strength (MOR), internal bond strength (IB), as well as formaldehyde content, were determined in accordance with the corresponding European standards. Overall, the HDF panels exhibited very satisfactory physical and mechanical properties, fully complying with the standard requirements of HDF for use in load-bearing applications in humid conditions. Markedly, the formaldehyde content of the laboratory fabricated panels was extremely low, ranging between 0.7–1.0 mg/100 g, which is, in fact, equivalent to the formaldehyde release of natural wood.

Albizia richardiana King & Prain as a raw material for ply and particleboard

2015 ◽  
Vol 22 (3) ◽  
pp. 139-141
Author(s):  
Md. Rahaman ◽  
Khurshid Akhter ◽  
S. Hossain ◽  
Md. Islam
Keyword(s):  
Bending Strength ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Solid Content ◽  
Raw Material ◽  
Standard Specification ◽  
Press Temperature ◽  
Albizia Richardiana ◽  
German Standard ◽  
Press Time

Woods of Albizia richardiana has been studied for assessing the suitability for plywood and particleboard manufacture. It was found that 1.5 mm thick smooth and figured veneer can be peeled and dried easily. Three-ply plywood were made using veneer of this species bonded with liquid urea formaldehyde glue of 50% solid content extended with wheat flour and catalyzed (ammonium chloride) with 2% hardener under the three specific pressures, viz,1.05 N/mm2, 1.40 N/mm2, 1.76 N/mm2 in three replications at 6 minute press time and 120°C press temperature. Dry and wet shear test were conducted on the sample and their shear load at failure per unit area and percentage of wood failure were determined. 1.05 N/mm2 pressure for the manufacture of plywood was found to be the best. The physical and mechanical properties of Albizia richardiana wood particleboard were studied. The particleboards were tested for determining the strength and dimensional stability. The tensile strength 0.56N/mm2 passed the British and German standard specification, bending strength (modulus of rupture10.80N/mm2) was found nearest to Indian Standard but low German and British standard specification.

scholarly journals Utilization of Partially Liquefied Bark for Production of Particleboards

2020 ◽  
Vol 10 (15) ◽  
pp. 5253 ◽  
Author(s):  
Wen Jiang ◽  
Stergios Adamopoulos ◽  
Reza Hosseinpourpia ◽  
Jure Žigon ◽  
Marko Petrič ◽  
...  
Keyword(s):  
Bending Strength ◽  
Urea Formaldehyde ◽  
Value Added ◽  
Thickness Swelling ◽  
Mechanical And Physical Properties ◽  
Dry Conditions ◽  
Synthetic Adhesives ◽  
European Standards ◽  
Muf Adhesives

Bark as a sawmilling residue can be used for producing value-added chemicals and materials. This study investigated the use of partially liquefied bark (PLB) for producing particleboard with or without synthetic adhesives. Maritime pine (Pinus pinaster Ait.) bark was partially liquefied in the presence of ethylene glycol and sulfuric acid. Four types of particleboard panels were prepared with a PLB content of 4.7%, 9.1%, 20%, and 33.3%, respectively. Another five types of particleboard panels were manufactured by using similar amounts of PLB and 10 wt.% of melamine–urea–formaldehyde (MUF) adhesives. Characterization of bark and solid residues of PLB was performed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and automated vapor sorption (AVS). Mechanical and physical properties of the particleboard were tested according to the European standards EN 310 for determining modulus of elasticity and bending strength, EN 317 for determining thickness swelling after immersion in water, and EN 319 for determining internal bond strength. The results showed that the increase in PLB content improved the mechanical strength for the non-MUF boards, and the MUF-bonded boards with up to 20% of PLB met the requirements for interior uses in dry conditions according to EN 312. The non-MUF boards containing 33.3% of PLB and the MUF-bonded boards showed comparable thickness swelling and water absorption levels compared to the reference board.

Peeling and Gluing Study of Khaya anthotheca for Ply and Particle Board

2015 ◽  
Vol 38 (2) ◽  
pp. 113-116
Author(s):  
Md. Rahaman ◽  
Khurshid Akhter ◽  
Md. Islam
Keyword(s):  
Bending Strength ◽  
Unit Area ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Solid Content ◽  
Shear Load ◽  
Particle Board ◽  
British Standard ◽  
Press Temperature ◽  
Press Time

Logs of Khaya anthotheca wood has been studied for assessing the suitability of plywood and particleboard manufacture. It was found that 1.5 mm thick smooth and figured veneer can be made and dried easily. Three-ply plywood were made using veneer of this species bonded with liquid urea formaldehyde glue of 50% solid content extended with wheat flour and catalyzed (ammonium chloride) with 2% hardener under the specific pressures, viz, 1.05 N/mm2, 1.40 N/mm2, 1.76 N/mm2 in three replications at 6 minute press time and 120°C press temperature. Dry and wet shear test were conducted on the sample and their shear load at failure per unit area and percentage of wood failure were determined. 1.05 N/mm2 pressure for the manufacture of ply wood was found to be the best. The physical and mechanical properties of K.anthotheca particleboard were studied. The particleboards were tested for determining the strength and dimensional stability. The tensile strength (internal bond strength 0.68 N/mm2) passed the German and British standard specifications; bending strength (modules of rupture 11.25 N/mm2) passed the Indian Standard but did not pass the German and British standard specifications.

scholarly journals USE OF ARTIFICIAL NEURAL NETWORKS IN PREDICTING PARTICLEBOARD QUALITY PARAMETERS

2016 ◽  
Vol 40 (5) ◽  
pp. 949-958 ◽  
Author(s):  
Rafael Rodolfo de Melo ◽  
Eder Pereira Miguel
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Bending Strength ◽  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Eucalyptus Grandis ◽  
Physical And Mechanical Properties ◽  
Quality Parameters ◽  
Physical Density ◽  
Artificial Neural

ABSTRACT This study aims to assess Artificial Neural Networks (ANN) in predicting particleboard quality based on its physical and mechanical properties. Particleboards were manufactured using eucalyptus (Eucalyptus grandis) and bonded with urea-formaldehyde and phenol-formaldehyde resins. To characterize quality, physical (density and water absorption and thickness swelling after 24-hour immersion) and mechanical (static bending strength and internal bond) properties were assessed. For predictions, adhesive type and particleboard density were adopted as ANN input variables. Networks of multilayer Perceptron (MLP) were adopted, training 100 networks for each assessed parameter. The results pointed out ANN as effective in predicting quality parameters of particleboards. With this technique, all the assessed properties presented models with adjustments higher than 0.90.

Study on Compressed Wood with Urea-Formaldehyde Prepolymer

2011 ◽  
Vol 675-677 ◽  
pp. 411-414
Author(s):  
Guo Feng Wu ◽  
Yi Fei Jiang ◽  
Ping Qu ◽  
Sheng Yao ◽  
Jun Wen Pu
Keyword(s):  
Dimensional Stability ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Basic Density ◽  
Physical And Mechanical Properties ◽  
Degree Of Crystallinity ◽  
Hot Press ◽  
Drying Treatment ◽  
Compressed Wood ◽  
Modified Wood

In this research, the urea-formaldehyde prepolymer and multilayer hot-press drying was used to obtain modified wood. The timbers were compressed and dried by the multilayer hot-press drying kiln. The combination of chemical modification and hot-press drying can improve the drying rate, which can also enhanced the physical and mechanical properties. Based on the findings, the basic density of modified wood improved 25.2 %, the bending strength and the bend elastic modulus improved 15.6 % and 25.0 % respectively. The dimensional stability of the treatment appeared to be slightly higher than that of untreated samples under the same conditions for processing temperatures and times. The improving dimensional stability of wood mainly was attributed to the prepolymer that changes wood cell wall components such as the degradation of the hemicelluloses and cellulose during hot-press drying treatment. The XRD results indicated that the degree of crystallinity increased to 35.45 %from 31.25 %. The TGA results show that the degradation of the samples can be divided into two step, both of the maximum weight loss velocity temperature of the two step increased to 266 °C, 355 °C from 244 °C and 341 °C.

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