scholarly journals Adhesion performance of melamine-urea–formaldehyde joints of copper azole-treated Eucalyptus grandis at varied bonding process conditions

2022 ◽  
Vol 314 ◽  
pp. 125682
Author(s):  
Adefemi Adebisi Alade ◽  
Zahra Naghizadeh ◽  
Coenraad Brand Wessels ◽  
Hannes Stolze ◽  
Holger Militz
Keyword(s):  
Urea Formaldehyde ◽  
Eucalyptus Grandis ◽  
Bonding Process ◽  
Process Conditions ◽  
Adhesion Performance ◽  
Copper Azole

Effect of process conditions on product yield and composition of fast pyrolysis of Eucalyptus grandis in fluidized bed reactor

2014 ◽  
Vol 20 (4) ◽  
pp. 2594-2602 ◽  
Author(s):  
Aghdas Heidari ◽  
Ralph Stahl ◽  
Habibollah Younesi ◽  
Alimorad Rashidi ◽  
Nicole Troeger ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Fast Pyrolysis ◽  
Eucalyptus Grandis ◽  
Fluidized Bed Reactor ◽  
Product Yield ◽  
Process Conditions

scholarly journals Preparation and Molecular Dynamics Simulation of RDX/MUF Nanocomposite Energetic Microspheres with Reduced Sensitivity

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 692
Author(s):  
Jia ◽  
Hu ◽  
Xu ◽  
Liu ◽  
Ma ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Binding Energy ◽  
Emulsion Polymerization ◽  
Md Simulation ◽  
Urea Formaldehyde ◽  
Urea Formaldehyde Resin ◽  
Experimental Results ◽  
Dynamics Simulation ◽  
Formaldehyde Resin ◽  
Process Conditions

In order to improve the general problem of irregular coating morphology and low mechanical strength of the coating layer in existing coating desensitization technology, nano-cyclotrimethylene trinitramine/melamine-urea-formaldehyde (RDX/MUF) composite energetic microspheres were prepared by an improved emulsion polymerization, taking the MUF as the binder and RDX as the main explosive. In order to judge whether RDX/MUF possessed good stability, the combination of differential scanning calorimetry (DSC) and molecular dynamics (MD) simulation was used to determine the level of binding binding energy between urea-formaldehyde resin binder (UF) and RDX. In addition, to investigate the optimal reaction temperature for the preparation of MUF/RDX, the binding energy between UF and RDX at different temperatures was simulated. And then the morphology and thermal properties of the as-prepared composite energetic microspheres were analyzed by scanning electron microscopy (SEM) and DSC, the impact sensitivity and friction sensitivity of the resultant samples were tested as well. Moreover, RDX/MUF with the same MUF content was prepared by physical mixing for comparative analysis. MD simulation demonstrated that UF and RDX possessed good binding ability at 298 K. The DSC method indicatec that UF and RDX had good compatibility, and the comprehensive performance of RDX after coating was not significantly deteriorated; The optimal binding temperature between UF and RDX was 60~70 °C which is consistent with the experimental results. The experimental results showed that the optimum process conditions for the preparation of RDX/MUF could be listed as follows: the temperature for preparing RDX/MUF composite energetic microspheres by the improved emulsion polymerization was 70 °C the optimal pH value of the urea-formaldehyde resin prepolymer solution was 3, and the optimal melamine-urea molar ratio was 0.4.

scholarly journals Optimization of Weld-bonding Process Conditions of Dissimilar Materials using Delta Spot Welding

2019 ◽  
Vol 37 (3) ◽  
pp. 231-236 ◽  
Author(s):  
Young-Hyun Kim ◽  
Young-Gon Kim ◽  
Dong-Cheol Kim ◽  
Sung-Min Joo
Keyword(s):  
Spot Welding ◽  
Dissimilar Materials ◽  
Bonding Process ◽  
Process Conditions ◽  
Weld Bonding

Study on Anodic Bonding Process of Slender Vitreous Body

2012 ◽  
Vol 503 ◽  
pp. 435-439
Author(s):  
Ming Qiang Pan ◽  
Li Guo Chen ◽  
Tao Chen ◽  
Zhen Hua Wang ◽  
Li Ning Sun
Keyword(s):  
Body Shape ◽  
Pressure Sensors ◽  
Vitreous Body ◽  
Bonding Process ◽  
Anodic Bonding ◽  
Interface Temperature ◽  
Process Conditions ◽  
Mems Devices ◽  
Bonding Failure ◽  
Mems Technology

With the development of MEMS technology, the pressure sensors, one of mature MEMS devices, are expected to better performance. In order to improve sensors performance, supporting vitreous body shape is elongated and thinned. But the variety of the vitreous body shape brings the new difficulties for anodic bonding between the vitreous body and the silicon during the sensors production, and causes that the common bonding process conditions are unavailable and bonding failure rate dramatically increases. Therefore, this article analyzes the bonding process between slender vitreous body and silicon, and researches on the influence of the vitreous body variety on the pressure, temperature and voltage. The results showed that the bonding is the best when the cantilever elastic deformation is less than 0.5mm, interface temperature loaded from the silicon is 415°C and the voltage 1200V is loaded from the position near H=2mm.

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.

scholarly journals EMBALAGENS CARTONADAS COMO MATÉRIA-PRIMA NA FABRICAÇÃO DE COMPÓSITOS

Nativa ◽  
2018 ◽  
Vol 6 (2) ◽  
pp. 177
Author(s):  
Talita Baldin ◽  
Maiara Talgatti ◽  
Amanda Grassamann da Silveira ◽  
Bruna Gabrieli Resner ◽  
Elio José Santini
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
Internal Bond ◽  
Urea Formaldehyde ◽  
Eucalyptus Grandis ◽  
Raw Material ◽  
Thickness Swelling ◽  
Wood Particles ◽  
Sustainable Materials ◽  
Waste Particles

O objetivo do presente trabalho foi avaliar o potencial de uso de partículas de resíduos de embalagens cartonadas e partículas de Eucalyptus grandis para a fabricação de compósitos, colados com adesivo à base de ureia-formaldeído. Foram utilizadas cinco diferentes proporções de madeira de E. grandis e embalagens cartonadas. As partículas de madeira e embalagens cartonadas foram produzidas em laboratório. A avaliação da qualidade dos compósitos envolveu a caracterização da geometria das partículas, das propriedades físicas: massa específica básica, teor de umidade de equilíbrio, absorção de água e inchamento em espessura após 2 e 24 horas de imersão em água e das propriedades mecânicas: flexão estática (MOE e MOR), resistência ao arrancamento de parafuso, ligação interna e dureza Janka. A incorporação de partículas de embalagens cartonadas proporcionou uma melhoria nas propriedades físicas em relação aos compósitos puros de madeira. Já para as propriedades mecânicas, compósitos com até 50% de embalagens cartonadas obtiveram melhores resultados, no entanto, a incorporação a partir de 75% ocasionou decadência nessas propriedades. Compósitos de madeira de E. grandis e embalagens cartonadas apresentaram potencial para utilização em ambientes internos e podem ser uma alternativa para a produção de compósitos sustentáveis e de boa qualidade.Palavra-chave: materiais sustentáveis, propriedades físicas e mecânicas, ureia-formaldeído. CARTONBOARD PACKAGING AS A RAW MATERIAL IN THE MANUFACTURE OF COMPOSITES ABSTRACT:The aim of this study was to evaluate the potential waste particles use of carton packaging and particles of E. grandis for the manufacture of particle boards, bonded with urea-formaldehyde-based adhesive. Five different proportions of E. grandis wood and cartons have been used. The wood particles and cartons were produced in the laboratory. The quality assessment panels involved characterizing the geometry of the particles, the physical properties: specific gravity, equilibrium moisture content, water absorption and thickness swelling after 2 and 24 hours of immersion in water and mechanical properties: flexural static (MOR and MOE), resistance to screw pullout, internal bond and Janka hardness. The incorporation of particulate cartons provided an improvement in physical properties relative to pure wood panels. As for the mechanical properties, panels of up to 50 % of cartons obtained best results, however, incorporating from 75 % decay caused these properties. The wood particleboard of E. grandis and cartons showed potential for use indoors and become an alternative for producing sustainable panels and of good quality.Keywords: sustainable materials, physical-mechanical properties; urea-formaldehyde. DOI:

Processing Variable Optimization of Plywood Hot Pressed with Ba2+-Modified Phenol-Formaldehyde Resin by a Response Surface Method

2019 ◽  
Vol 69 (2) ◽  
pp. 148-153
Author(s):  
Zhangmin Chen ◽  
Yuhe Chen ◽  
Hanjiang Cai ◽  
Jian Han
Keyword(s):  
Shear Strength ◽  
Response Surface ◽  
Hot Pressing ◽  
Phenol Formaldehyde ◽  
Phenol Formaldehyde Resin ◽  
Bonding Process ◽  
Formaldehyde Resin ◽  
Process Conditions ◽  
Curing Agent ◽  
Processing Variable

Abstract Ba(OH)2 was added in the synthesis of phenol-formaldehyde resin to realize a low-temperature and fast-bonding process for plywood production. Plywood bonding was investigated by studying a number of parameters, such as the glue spread, the amount of curing agent, and the temperature and duration of the hot-pressing process. The plywood bonding strength was characterized by the shear strength of the adhesive layer, and a mathematical model describing the process and the response was developed using a central composite design and response surface methods. The variance analysis revealed that the newly developed model was reliable, with a high signal-to-noise ratio. All the factors and their interactions were analyzed to optimize the bonding process. Thus, seven optimized processes were obtained from the model, and the optimal process conditions were revealed (glue spread: 277.8 g/m2; amount of curing agent: 3.5%; hot-pressing temperature: 108°C; and hot-pressing duration: 34.99 s/mm). The results from repeated average shear strength experiments of five veneer testing samples (1.64 MPa) verified the reliability of the optimized technics.

Sign in / Sign up

Export Citation Format

Share Document