scholarly journals PRODUCTION OF BOLAINA (Guazuma crinita Mart) PLYWOOD GLUED WITH UREA-FORMALDEHYDE AND PHENOL-FORMALDEHYDE RESINS

FLORESTA ◽  
2022 ◽  
Vol 52 (1) ◽  
pp. 197
Author(s):  
Milciades Leonidas Miguel Castro ◽  
Setsuo Iwakiri ◽  
Rosilani Trianoski ◽  
Hector Henrique Gonzales Mora
Keyword(s):  
Phenol Formaldehyde ◽  
Urea Formaldehyde

scholarly journals Lignosulphonates as an Alternative to Non-Renewable Binders in Wood-Based Materials

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4196
Author(s):  
Sofia Gonçalves ◽  
João Ferra ◽  
Nádia Paiva ◽  
Jorge Martins ◽  
Luísa H. Carvalho ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Aromatic Ring ◽  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Value Added ◽  
Wood Adhesives ◽  
Renewable Source ◽  
Pressing Time ◽  
Value Added Products ◽  
Total Market

Lignin is a widely abundant renewable source of phenolic compounds. Despite the growing interest on using it as a substitute for its petroleum-based counterparts, only 1 to 2% of the global lignin production is used for obtaining value-added products. Lignosulphonates (LS), derived from the sulphite pulping process, account for 90% of the total market of commercial lignin. The most successful industrial attempts to use lignin for wood adhesives are based on using this polymer as a partial substitute in phenol-formaldehyde or urea-formaldehyde resins. Alternatively, formaldehyde-free adhesives with lignin and lignosulphonates have also been developed with promising results. However, the low number of reactive sites available in lignin’s aromatic ring and high polydispersity have hindered its application in resin synthesis. Currently, finding suitable crosslinkers for LS and decreasing the long pressing time associated with lignin adhesives remains a challenge. Thus, several methods have been proposed to improve the reactivity of lignin molecules. In this paper, techniques to extract, characterize, as well as improve the reactivity of LS are addressed. The most recent advances in the application of LS in wood adhesives, with and without combination with formaldehyde, are also reviewed.

scholarly journals Environmentally-Friendly High-Density Polyethylene-Bonded Plywood Panels

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1166 ◽  
Author(s):  
Pavlo Bekhta ◽  
Ján Sedliačik
Keyword(s):  
Mechanical Properties ◽  
Hot Pressing ◽  
High Density Polyethylene ◽  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Core Layer ◽  
High Density ◽  
Pressing Pressure ◽  
Pressing Time

Thermoplastic films exhibit good potential to be used as adhesives for the production of veneer-based composites. This work presents the first effort to develop and evaluate composites based on alder veneers and high-density polyethylene (HDPE) film. The effects of hot-pressing temperature (140, 160, and 180 °C), hot-pressing pressure (0.8, 1.2, and 1.6 MPa), hot-pressing time (1, 2, 3, and 5 min), and type of adhesives on the physical and mechanical properties of alder plywood panels were investigated. The effects of these variables on the core-layer temperature during the hot pressing of multiplywood panels using various adhesives were also studied. Three types of adhesives were used: urea–formaldehyde (UF), phenol–formaldehyde (PF), and HDPE film. UF and PF adhesives were used for the comparison. The findings of this work indicate that formaldehyde-free HDPE film adhesive gave values of mechanical properties of alder plywood panels that are comparable to those obtained with traditional UF and PF adhesives, even though the adhesive dosage and pressing pressure were lower than when UF and PF adhesives were used. The obtained bonding strength values of HDPE-bonded alder plywood panels ranged from 0.74 to 2.38 MPa and met the European Standard EN 314-2 for Class 1 plywood. The optimum conditions for the bonding of HDPE plywood were 160 °C, 0.8 MPa, and 3 min.

Influence of Nanoclay on Phenol-Formaldehyde and Phenol-Urea-Formaldehyde Resins for Wood Adhesives

2010 ◽  
Vol 24 (8-10) ◽  
pp. 1567-1576 ◽  
Author(s):  
H. Lei ◽  
G. Du ◽  
A. Pizzi ◽  
A. Celzard ◽  
Q. Fang
Keyword(s):  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Wood Adhesives

ECO-Adhesive from Modified Natural Rubber for Wood Applications

2013 ◽  
Vol 844 ◽  
pp. 182-185 ◽  
Author(s):  
Sunisa Suchat ◽  
Wisanee Yingprasert
Keyword(s):  
Shear Strength ◽  
Natural Rubber ◽  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Dry Weight ◽  
Health Concern ◽  
Lower Shear ◽  
Liquid Natural Rubber ◽  
The Government ◽  
Solids Content

Both commercial entities and the government have expressed interest in safe and environ-mentally friendly adhesives, ECO-adhesives, containing no volatile harmful or toxic chemicals. In the wood industries, currently common adhesives such as urea formaldehyde (UF), phenol formaldehyde (PF) release formaldehyde vapors that are a human health concern, with unpleasant odor. We examined the potential of modified natural rubber latexes (MNRL) for use as ECO-adhesives. Three latex types were used, namely epoxidized natural rubber (ENR), liquid natural rubber (LNR), and NR/PMMA blend. The MNRL was characterized by FT-IR, NMR, and GPC. The proportion of tackifying agent to the dry weight of latex was varied in the range 0 to 60 phr. It was found that the MNRL uniformly mixed in the latex form. All MNRL adhesives would have passed the Thai standard for rubber-based adhesives, based on their: total solids content (TSC), pH, viscosity, shear strength, and emissions of formaldehyde. Up to 30% fraction of tackifying agent, tack and shear strength increased with its content. Compared to a commercial UF adhesive, the MNRL had lower emissions of formaldehyde vapors, lower shear strength, but higher TSC, and higher viscosity. In summary, for select wood applications with moderate bond shear demands, these new rubber based adhesives could provide a health conscious and non-toxic alternative, with the further advantage of low odor.

Surface Characteristic of Wheat Straw Treated with Plasma

2011 ◽  
Vol 295-297 ◽  
pp. 1639-1642 ◽  
Author(s):  
Hai Yan Mao ◽  
Ding Guo Zhou ◽  
Sun Guo Wang ◽  
Rui Yang
Keyword(s):  
Plasma Treatment ◽  
Wheat Straw ◽  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Natural Fibers ◽  
Cost Effective ◽  
Surface Characteristic ◽  
Contact Angles ◽  
Ftir Analysis ◽  
Waxy Wheat

The waxy wheat straw surface and high SiO2content of wheat straw agrifibres make wheat straw-based panel production much more difficult than traditional wood-based panel manufacture. Plasma surface modification is regarded as one of the cost effective surface treatment techniques for many materials including natural fibers. In this study, plasma technique was employed to treat the surface of wheat straw. After the plasma treatment, the surface properties were then evaluated by determining the contact angles of 3 liquids on the wheat straw surface and by analysis using Fourier Transform Infrared Spectroscopy (FTIR).The results showed that the contact angles of water, glycerol, and UF resin after the plasma treatment decreased by 44.1%, 18.6%, and 24.9%, respectively. In the meantime, –OH, and -C=O groups increased according to the FTIR analysis. The FTIR analysis also indicated a significant SiO2reduction in the plasma treated wheat straw. Obviously, the plasma treatment improved the wettability of wheat straw, increased the numbers of oxygen-containing functional groups, and also removed the weak interface of wheat straw remarkably. By means of the plasma treatment, the internal bond property between modified wheat straw fibers was expected to enhance, and thus some cheaper traditional adhesives such as urea formaldehyde (UF) and phenol formaldehyde (PF) can be used for the wheat straw-based panel production instead of using expensive Diphenylmethane Diisocyanate (MDI).

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.

A Study of the Properties of Animal-Based Wood Glue

2014 ◽  
Vol 935 ◽  
pp. 133-137 ◽  
Author(s):  
Ehsan Taghizadeh Tousi ◽  
Rokiah Hashim ◽  
Sabar Bauk ◽  
Mohamad Suhaimi Jaafar ◽  
Amer Mahmoud Al-Jarrah ◽  
...  
Keyword(s):  
Crude Protein ◽  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Wood Adhesive ◽  
Crude Fiber ◽  
Connective Tissues ◽  
Wood Industry ◽  
Adhesive Properties ◽  
Organic Components ◽  
Nitrogen Free Extract

In this study, the green animal-based, which has been prepared by prolonged boiling of the inedible connective tissues of domesticated ungulates, was investigated for adhesive properties. The viscosity of green animal-based wood adhesive was measured and compared with that of urea-formaldehyde (UF) and phenol-formaldehyde (PF) which are widely used synthetic glues in the wood industry. Also, the crude protein, crude fat, crude fiber, nitrogen free extract (NFE) that represents carbohydrate, and ash as the organic components of green animal-based glue was measured. According to the results, the green animal-based wood glue was found suitable to be used in wood industry.

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