Assessment of risk in consumer manufacturing low toxic plywood

2015 ◽  
Vol 5 (4) ◽  
pp. 123-129
Author(s):  
Анисимов ◽  
Maksim Anisimov
Keyword(s):  
Influencing Factors ◽  
High Frequency ◽  
Urea Formaldehyde ◽  
Formaldehyde Resin ◽  
Technological Properties ◽  
Pulsed Magnetic Fields ◽  
Adhesive Compositions ◽  
Wide Range ◽  
Materials Used ◽  
Simplified Calculation

Currently, the use of wood plate materials (WPM) in various industries is steadily increasing due to a number of technological and economic advantages. Along with this, there is the improvement of methods of manufacturing and materials used for this purpose. One of the most commonly types of glue used for production of plywood as one of the types of WPM are urea-formaldehyde resins. In the manufacture of adhesive compositions based on them possible to use a wide range of sorbents that provide a variety of improved technological properties, such as adhesive, and the finished plywood. One of these properties is the level of free formaldehyde emissions from finished plywood, which directly affects to the possibility of its using in different rooms and characterizes the level of consumer risks in its operation. Scientifically it proved possible to reduce the level of emission of free formaldehyde from finished plywood with using of natural zeolite clinoptilolite treated in weak pulsed magnetic fields (SIMP) and ultra-high frequency electromagnetic fields (EMF microwave), as a sorbent of urea-formaldehyde resin filler in the manufacture of plywood for general using. This study evaluated the level of consumer risks in the operation of plywood manufactured with sorbent activated in SIMP and microwave EMF. In this paper describes the main influencing factors as well as the possibility of reducing calculation errors in consumer risk shows the feasibility of using a simplified calculation of constant values while respecting the basic influencing factors. Calculations of changes in con-sumer risk for saples of plywood manufactured with using sorbents, activated in SIMP and EMF microwave were made, established decrease by 25 and 33 % respectively.

Influence of electromagnetic treatment of fillers on physical and chemical properties of the adhesive compositions for plywood manufacture

10.12737/4518 ◽  
2014 ◽  
Vol 4 (2) ◽  
pp. 135-144
Author(s):  
Бельчинская ◽  
Larisa Belchinskaya ◽  
Анисимов ◽  
Maksim Anisimov ◽  
Попов ◽  
...  
Keyword(s):  
High Frequency ◽  
Chemical Properties ◽  
Adhesive Layer ◽  
Internal Stresses ◽  
Pulsed Magnetic Fields ◽  
Electromagnetic Treatment ◽  
Adhesive Compositions ◽  
Reduction Of Emissions ◽  
Physical And Chemical ◽  
And Chemical Properties

During this work the reduction of emissions of free formaldehyde of the cured adhesive composition for the manufacture of environmentally friendly plywood is identified, through the introduction of pre-activated sorbent of fillers into its composition, as well as reducing internal stresses in the adhesive layer of the cured binder. The resulting effects are related with the use of adhesive formulations of different sorbents fillers subjected to preactivation in various electromagnetic fields (fields over high frequency and weak pulsed magnetic fields).

scholarly journals Effect of Technical Aerosil on the Properties of Adhesive Compositions

2021 ◽  
pp. 133-144
Author(s):  
Ekaterina G. Sokolova ◽  
◽  
Dmitry S. Rusakov ◽  
Galina S. Varankina ◽  
Anatoly N. Chubinsky
Keyword(s):  
Water Resistance ◽  
Deep Structure ◽  
Raw Materials ◽  
Phenol Formaldehyde ◽  
Physical Adsorption ◽  
Urea Formaldehyde ◽  
High Water ◽  
Complex Compounds ◽  
Adhesive Compositions ◽  
Wide Range

The main drivers of competition among the products made with the use of adhesive compositions are the toxicity of finished products, the consumption of raw materials and energy resources, the duration of the main technological operations. These drivers can be controlled by using adhesives with different fillings and/or modifications. Adhesives based on phenol-formaldehyde and melamine-urea-formaldehyde resins are used to produce plywood with increased water resistance. Apart from resins, adhesives usually contain hardeners, fillers, and modifiers that affect the properties of the finished product. Technical aerosol is one of the modifiers of synthetic resins with a wide range of action. Aerosil is characterized by three types of interaction: physical adsorption, chemical adsorption (formation of hydrogen bridges by silanol groups), and chemical reactions on the surface layer. The chemical composition of aerosil was analyzed. Technical aluminum fluoride (AlF3) is of particular interest. It can interact with alkali metal fluorides with the formation of complex compounds that improve polymer structuring. The acids that make up aerosil reduce the pH to 2.0–3.5, so they can be catalysts for the curing process of melamine-urea-formaldehyde resins. The effect of technical aerosil on the properties of adhesive systems based on phenol-formaldehyde and melamine-ureaformaldehyde resins has been studied. Viscosity, curing time, and wetting ability of adhesive compositions were determined. The obtained results indicate the possibility of using this modifier in the composition of phenol-formaldehyde and melamine-urea-formaldehyde resins up to 15 pts. wt. The nature of the aerosil action on adhesive compositions was determined using IR spectroscopy. Analysis of the results showed that aerosil promotes deep structure formation of the polymer by increasing the molecular weight of the molecules. These bonds make it possible to form a more structured polymer with bound formaldehyde. Studies of the effect of aerosil on the properties of finished products were carried out. At the same time, an increase in performance indicators was found: the strength of adhesion increases, the toxicity of plywood decreases. The results of experiments on the effect of technical aerosil, taking into account the reduction of bonding time can be applied in the development of technological processes for obtaining plywood of high water resistance. For citation: Sokolova E.G., Rusakov D.S., Varankina G.S., Chubinsky A.N. Effect of Technical Aerosil on the Properties of Adhesive Compositions. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 3, pp. 133–144. DOI: 10.37482/0536-1036-2021-3-133-144

scholarly journals Postprocessing Study for the Controllable Structures of Ceramic Green Parts Realized by a Flexible Binder Jetting Printing (BJP) Solution

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Shu Cao ◽  
Fangxia Xie ◽  
Xueming He ◽  
Chaofeng Zhang ◽  
Meiping Wu
Keyword(s):  
Flexural Strength ◽  
Atmospheric Pressure ◽  
Structural Characteristics ◽  
Urea Formaldehyde ◽  
Strengthening Mechanism ◽  
Formaldehyde Resin ◽  
Surface Strengthening ◽  
Ceramic Slurry ◽  
Wide Range ◽  
Binder Jetting

For indirect ceramic additive manufacturing (AM), green parts’ initial densities are low, limiting the postprocessing strengthening under atmospheric pressure. This study employed binder jetting printing (BJP) based on the polycondensation curing of urea-formaldehyde resin to produce series of Al2O3 green specimens with controllable structures. Further, an integrated postprocessing procedure, including the sequential stages of presintering, ceramic slurry infiltration, and final sintering, was conducted on these green specimens with designed structural characteristics for verifying strengthening mechanism. Using a self-developed BJP machine system and the related material which are flexible in process, this study printed green specimens with strong bonding (flexural strength above 6.84 MPa), additionally can regulate their initial densities within the wide range between 21.7%∼43.9%. Infiltrated with ceramic slurry, low-density green specimens were significantly strengthened via final sintering, realizing final densities, flexural strength, and compressive strength of 73.2%, 43.15 MPa, and 331.17 MPa, respectively. In comparison, high-density specimens performing poor infiltration obtained limited density increment after final sintering, but better mechanical properties and surface strengthening were realized, exhibiting final densities, flexural strength, comprehensive strength, surface roughness Ra, and Vickers hardness of 70.1%, 63.22 MPa, 450.18 MPa, 9.73 μm, and 4.58 GPa, respectively. In summary, this study is helpful to provide the technical reference for custom AM ceramic green parts and the postprocessing optimization.

Influence of Shungite Modificator on Technological Properties of Polymeric Glue Based on Urea-Formaldehyde Resin

2020 ◽  
Vol 992 ◽  
pp. 434-438
Author(s):  
Nikolai Gennadievich Panov ◽  
Sergey Borisovich Vasilyev ◽  
Gennady Nikolaevich Kolesnikov
Keyword(s):  
Mechanical Properties ◽  
Urea Formaldehyde ◽  
Wood Particle ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Technological Properties

Previously it has been experimentally established that modification of polymeric glue on the basis of urea-formaldehyde resin by adding shungite powder leads to improvement of physical-mechanical properties of wood-particle boards. The goal of the investigation was to establish the influence of the shungite powder, consisting of particles in the size from 50 to 100 nanometers, on such technological properties of glue, as duration of gelatinization and viscosity. It was established: the shortest duration of gelatinization for glues was achieved with shungite addition of 10%; the lowest viscosity depends on the composition of the glue and was achieved with shungite addition from 5 to 10%.

scholarly journals Effects of Three Biomass Fillers on the Properties of Melamine Modified Urea-Formaldehyde Resin

2020 ◽  
Vol 782 ◽  
pp. 022077
Author(s):  
Shanfeng Xu ◽  
Sanshan Xia ◽  
Yuzhu Chen ◽  
Hui Xiao ◽  
Maoyu Yi ◽  
...  
Keyword(s):  
Urea Formaldehyde ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Modified Urea

scholarly journals Bio-Based Alternatives to Phenol and Formaldehyde for the Production of Resins

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2237 ◽  
Author(s):  
P. R. Sarika ◽  
Paul Nancarrow ◽  
Abdulrahman Khansaheb ◽  
Taleb Ibrahim
Keyword(s):  
Raw Materials ◽  
Phenol Formaldehyde ◽  
Raw Material ◽  
Wood Industry ◽  
Suitable Material ◽  
The Past ◽  
Wide Range ◽  
Recent Developments ◽  
Sustainable Materials ◽  
Materials Used

Phenol–formaldehyde (PF) resin continues to dominate the resin industry more than 100 years after its first synthesis. Its versatile properties such as thermal stability, chemical resistance, fire resistance, and dimensional stability make it a suitable material for a wide range of applications. PF resins have been used in the wood industry as adhesives, in paints and coatings, and in the aerospace, construction, and building industries as composites and foams. Currently, petroleum is the key source of raw materials used in manufacturing PF resin. However, increasing environmental pollution and fossil fuel depletion have driven industries to seek sustainable alternatives to petroleum based raw materials. Over the past decade, researchers have replaced phenol and formaldehyde with sustainable materials such as lignin, tannin, cardanol, hydroxymethylfurfural, and glyoxal to produce bio-based PF resin. Several synthesis modifications are currently under investigation towards improving the properties of bio-based phenolic resin. This review discusses recent developments in the synthesis of PF resins, particularly those created from sustainable raw material substitutes, and modifications applied to the synthetic route in order to improve the mechanical properties.

scholarly journals Calcium carbonate modified urea–formaldehyde resin adhesive for strength enhanced medium density fiberboard production

RSC Advances ◽  
2021 ◽  
Vol 11 (40) ◽  
pp. 25010-25017
Author(s):  
Li Lu ◽  
Yan Wang ◽  
Tianhua Li ◽  
Supeng Wang ◽  
Shoulu Yang ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Urea Formaldehyde ◽  
Medium Density Fiberboard ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Medium Density ◽  
Ionic Bond ◽  
Resin Adhesive ◽  
Uf Resin ◽  
Modified Urea

Reactions between CaCO3 and CH2O2 during polycondensation of UF resin produce Ca2+. Ionic bond complexation binds Ca2+ with UF resin. The UF resin crystalline percentage decreases from 26.86% to 22.71%. IB strength of resin bonded fiberboard increases from 0.75 to 0.94 MPa.

scholarly journals Assembling Surface Linker Chemistry with Minimization of Non-Specific Adsorption on Biosensor Materials

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 472
Author(s):  
Jack Chih-Chieh Sheng ◽  
Brian De La Franier ◽  
Michael Thompson
Keyword(s):  
High Frequency ◽  
Biological Fluid ◽  
Sensor Technology ◽  
Igg Antibody ◽  
Surface Attachment ◽  
Self Assembling ◽  
Materials Used ◽  
Aqueous Conditions ◽  
Acoustic Wave Device ◽  
Wave Device

The operation of biosensors requires surfaces that are both highly specific towards the target analyte and that are minimally subject to fouling by species present in a biological fluid. In this work, we further examined the thiosulfonate-based linker in order to construct robust and durable self-assembling monolayers (SAMs) onto hydroxylated surfaces such as silica. These SAMs are capable of the chemoselective immobilization of thiol-containing probes (for analytes) under aqueous conditions in a single, straightforward, reliable, and coupling-free manner. The efficacy of the method was assessed through implementation as a biosensing interface for an ultra-high frequency acoustic wave device dedicated to the detection of avidin via attached biotin. Fouling was assessed via introduction of interfering bovine serum albumin (BSA), IgG antibody, or goat serum. Improvements were investigated systematically through the incorporation of an oligoethylene glycol backbone employed together with a self-assembling diluent without a functional distal group. This work demonstrates that the incorporation of a diluent of relatively short length is crucial for the reduction of fouling. Included in this work is a comparison of the surface attachment of the linker to Si3N4 and AlN, both materials used in sensor technology.

scholarly journals Assessing evidence for adaptive evolution in two hearing-related genes important for high-frequency hearing in echolocating mammals

2021 ◽  
Author(s):  
Hui Wang ◽  
Hanbo Zhao ◽  
Yujia Chu ◽  
Jiang Feng ◽  
Keping Sun
Keyword(s):  
Adaptive Evolution ◽  
Hair Cells ◽  
High Frequency ◽  
Phylogenetic Trees ◽  
Outer Hair Cells ◽  
Functional Domain ◽  
Coding Region ◽  
Selective Pressures ◽  
Wide Range ◽  
Different Parts

Abstract High-frequency hearing is particularly important for echolocating bats and toothed whales. Previously, studies of the hearing-related genes Prestin, KCNQ4, and TMC1 documented that adaptive evolution of high-frequency hearing has taken place in echolocating bats and toothed whales. In this study, we present two additional candidate hearing-related genes, Shh and SK2, that may also have contributed to the evolution of echolocation in mammals. Shh is a member of the vertebrate Hedgehog gene family and is required in the specification of the mammalian cochlea. SK2 is expressed in both inner and outer hair cells, and it plays an important role in the auditory system. The coding region sequences of Shh and SK2 were obtained from a wide range of mammals with and without echolocating ability. The topologies of phylogenetic trees constructed using Shh and SK2 were different; however, multiple molecular evolutionary analyses showed that those two genes experienced different selective pressures in echolocating bats and toothed whales compared to non-echolocating mammals. In addition, several nominally significant positively selected sites were detected in the non-functional domain of the SK2 gene, indicating that different selective pressures were acting on different parts of the SK2 gene. This study has expanded our knowledge of the adaptive evolution of high-frequency hearing in echolocating mammals.

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