Fiber direction of external veneer sheets of cross-grained plywood is perpendicular to the largest side of the plywood sheet. Fiber direction of external veneer sheets of long-grained plywood is parallel to the largest side of the plywood sheet. B Grade: Practical absence of defects. Standalone healthy intergrown knots up to 25 mm in diameter are allowed, or knot holes up to 5 mm in diameter.
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- MDF vs Plywood; which should you choose for your project?
- E0 Glue - Plywood Adhesive, 200 Kg, Adhesive Grade: Industrial Grade
- Fumed silica as a filler for MUPF resin in the process of manufacturing water-resistant plywood
- The Plywood Floor – 15 months on…
- Life Cycle Assessment of Plywood Manufacturing Process in China
- Birch Plywood
- Applications of Tannin Resin Adhesives in the Wood Industry
- History of APA, Plywood, and Engineered Wood
- Curved plywood
MDF vs Plywood; which should you choose for your project?VIDEO ON THE TOPIC: Remove layers of linoleum glued and stuck to wood plywood underlayment using a Spyder Tool.
This work examines the effect of applying fumed silica with nanoscopic-size particles as a filling material for melamine-urea-phenol-formaldehyde MUPF resin in the process of manufacturing water-resistant plywood. Moreover, this paper investigates the possibility of reducing the amount of MUPF resin mixture used in the process of gluing veneer sheets. Based on the investigations into the reactivity, viscosity and durability of MUPF resin mixture containing various amounts of nanofiller, it was found that the optimum amount of silica that can make the resin suitable for gluing sheets of veneer amounts to 2 PBW per PBW of MUPF resin.
The gluing properties for thus mixed resin were determined by measuring the contact angle and determining the parameters of its derivatives, which are an additional criterion for evaluating the gluing properties. The experimental plywood manufactured using optimal nano-SiO 2 was tested in terms of bond quality and mechanical properties according to appropriate standards.
The investigations prove that it is possible to apply fumed silica as a filling material for the resin in the process of manufacturing water-resistant plywood. Introducing the above-mentioned amount of fumed silica into the resin makes it possible to increase the activation energy of the cross-linking process of MUPF resin and to optimize the process of gluing the sheets of veneer. The filling materials for resins, which are contemporarily used in plywood industry, enhance the reactivity of the adhesives and regulate their viscosity.
Thus, they restrain the excessive penetration of the resin into wood. Moreover, these fillers are made of relatively big particles, which limit their mobility in the cross-linking process and make it difficult to attain high level of homogenization.
Consequently, it is difficult to apply the resin mixture onto the surface of veneer and it is necessary to use a larger amount of resin. What is more, amylaceous substances used as fillers of amine resins are totally nonresistant to the action of fungi Proszyk In recent years, owing to the growing interest in nanotechnology and use of nanoparticles, it has been possible to produce a number of new materials of increased utilitarian value, better mechanical strength and higher resistance to chemical and thermal conditions.
In addition, the costs of their production have been optimized and reduced. At present the most commonly used filler with nanoscopic size of particles is silica, i. Silica is capable of creating both silicon nanostructures, consisting of only SiO 2 particles, and the hybrid ones where it plays the role of a core covered with a thin layer of another material. Nowadays the most widely used method of obtaining silica is the sol—gel process, in which silica is obtained from tetraethoxysilane TEOS , and fumed silica.
Numerous investigations on the possible uses of nanosilica show that it plays a crucial role in improving the properties of plastic.
It results from, for example, the presence of functional groups on its surface, the possibility of attaining high dispersion level and the nanoscopic size of initiating particles. According to Sadej-Bajerlain et al. A lot of plastics are characterized by insufficient resistance to the action of chemical substances as well as low dimensional stability and mechanical strength at increased temperatures. It is manifested by the increase in modulus of elasticity, modulus of rupture, internal bond, impact strength as well as thermal and chemical resistance.
It is also commonly known that fumed silica enhances thermal, rheological and mechanical properties of various types of adhesives, such as thermoplastic polyurethane Vega-Baudrit et al. Nanotechnology is an interdisciplinary branch of science and it creates new opportunities also in the field of wood science and technology. The greatest achievements so far have been attained for the coating of wood and wood based materials surface. Owing to nanotechnology, researchers developed a number of new, specialist, so-called smart coatings which are produced by using nano-SiO 2.
In case of liquid systems, the universal use of SiO 2 as a filler results from its strong condensing properties, which enhance the utilitarian value of paints, lacquers and adhesives Leder et al.
The spatial structure of silica protects the system from draining and improves the spreading and smoothness of coating. In the compositions including particulate matter, such as pigment, silica prevents them from sedimentation.
The presence of silica in lacquers and enamels enhances their thermal, optical and mechanical resistance, especially to abrasion and scratching. It also makes it possible to attain the desired gloss level of the coating Royall and Donald ; Sow et al.
The use of nano-SiO 2 in the system with urea resin and wood preservative enhances fire resistance of wood as well as its dimensional stability and durability Shi et al.
The review of literature on the subject shows that so far no extensive studies have been conducted on the use of nanosilica in the process of manufacturing wood based materials. Researchers investigated mainly the possibility of using fumed silica and colloidal silica as an auxiliary agent in the process of producing particleboards glued with urea-formaldehyde resin.
These research works determined the influence of silica on the structure of the cured UF resin and showed that the addition of silica into the resin results in the increase of its viscosity; yet, it does not significantly affect its cross-linking time or thermal stability and the produced boards have better physicomechanical properties Leonovich et al.
In these investigations, white pigment, in the form of titanium dioxide, and a small amount of nanosilica were introduced into the adhesive mixture and, therefore, the resin-pigment system became more stable.
The aim of the present work was to examine the effect of applying synthetic fumed silica with nanoscopic-size particles as a filling agent for MUPF resin in the process of manufacturing water-resistant plywood. Taking into consideration the relatively high price of MUPF resin, as well as the fact that, at present, the technology is focused on reducing the material costs, an attempt was made to produce experimental plywood using the minimum amount of MUPF mixed glue.
For research purposes, an industrial melamine-urea-phenol-formaldehyde resin Melfemo , produced by Silekol, Kedzierzyn-Kozle, Poland was used. To determine the optimum amount of silica, so that the resin has the proper utilitarian value, a number of tests were carried out using various amounts of nano-SiO 2 , i.
As the proper degree of homogenization and dispersion of nanofiller particles was needed to be attained, the mixed resin was made by using CAT homogenizer at RPM. Theories by Kissinger and Ozawa are based on the assumption that, for various heating rates, the maximum heat flow corresponds to the higher reaction rate.
The basis for determining the activation energy with these methods is the Arrhenius equation:. The DSC analysis interprets the equation as Kim et al.
Therefore, the dependence 1 can be shown as below equation. After having taken a logarithm of Eq. Additionally, for the resin with the selected amount of nano-SiO 2 , thermal stability in polythermal conditions was determined by carrying out the simultaneous TG—DSC thermal analysis.
Next, after the anti-adhesive film had been removed, a drop of redistilled water, with volume of 5. Taking into consideration the porous structure of wood, the contact angle was determined by means of the dynamic sessile drop method according to Eq.
The experimental plywood was produced from three layers of birch veneer with thickness of 1. Next, the quality of the bond was evaluated according to EN by shear testing f v after ageing tests. According to standard EN , tests required for class 2 bond quality were applied, i. The shear test was conducted on wet samples. To investigate the influence of nano-SiO 2 added to MUPF resin upon the class of formaldehyde release in the experimental boards, the level of formaldehyde emission was determined by means of the flask method according to EN To analyze the results of these investigations, a control sample was made according to an industrial recipe: MUPF resin with addition of a traditional amylaceous filler, i.
For each investigated variant, two sheets of plywood were produced and ten samples were collected from each sheet. The attained results were subjected to statistical analysis using Statistica software, version These values, determined using Kissinger and Ozawa methods, are lower than those of control samples variant 0 by max.
The phenomenon can be explained by the different dynamics of mass decrement and heat flow in the course of the cross-linking process in the investigated adhesives; these values, provided on the basis of TG and DSC thermal analysis, are discussed in more detail in the further part of the paper. The data included in Fig. By introducing 2 PBW of silica per PBW of the resin it was possible to attain viscosity values comparable to those of the control adhesive, which was made according to the industrial recipe.
Such a significant decrease in the dynamics of changes in time makes it possible to lengthen its durability in the production process when compared to the adhesive containing amylaceous filler. Adhesive mixtures containing less than 2 PBW of silica are characterized by lower viscosity than the reference resin, below the value attainable for industrial conditions. Using those adhesives for gluing sheets of veneers could result in excessive penetration of the resin into the veneer as well as bleed-through on their surface.
Moreover, the layer of adhesive remaining on the surface may be insufficient to produce a good quality bond Sellers That is why, in the further part of the research work, testing of these variants was given up.
Taking into consideration the results of tests on the reference adhesive and resin mixtures containing various amounts of nano-SiO 2 , the conclusion was drawn that the optimum amount of silica, that makes the adhesive useful, is 2 PBW per PBW of MUPF resin. The resin is then characterized by high homogeneity, proper reactivity and viscosity as well as durability required in the process of manufacturing plywood.
To get a full evaluation of the possible uses of fumed silica in the process of producing plywood glued with MUPF resin, its influence on thermal stability and adhesive properties of the resin were also determined. It is illustrated by thermogravimetric curves TG , characterizing changes of the mass, and the curves of differential scanning calorimetry DSC determining the thermal effects that accompany the chemical and physical changes in the investigated adhesives.
However, in the analyzed area, small peaks of exothermic character can be spotted which means that the short-term increase in the temperature is caused by the initiation of the adhesive polycondensation process. In this area, two peaks of endothermic character can be spotted. This is accompanied by mass decrement of approx. Based on DSC analysis Fig. This means that the rate of cross-linking reaction of the resin with the addition of nano-SiO 2 is higher than that of the resin with the amylaceous filler.
It explains the lower values of activation energy attained for the MUPF resin with the addition of nanofiller. According to the data from the literature on this subject, in this range of temperature, methylene bonds disintegrate and gas products are released Camino et al. At higher temperatures, the disintegration of the reference resin proceeds in a similar manner. It means that substituting amylaceous filler with fumed silica does not affect the thermal stability of MUPF resin. However, it makes it possible to reduce the amount of energy needed in the cross-linking process of the resin.
The analysis of the obtained results shows that substituting amylaceous filler with nano-SiO 2 results in a slight increase of contact angle as well as the value of free surface energy of the system solid—liquid.
It is accompanied by a minor decrease in surface tension on the phase boundary and the ratio of its polar components. It leads to the conclusion that the resin mixture including 2 PBW of nano-SiO 2 shows slightly worse adhesive properties than the resin with the addition of traditional filler. The influence of the addition of 2 PBW of nano-SiO 2 per PBW of MUPF resin on the properties of experimental plywood was investigated as well as the possibility of reducing the amount of adhesive in the process of gluing sheets of veneer by determining the bond quality as well as modulus of rupture and modulus of elasticity in both grain directions in the face layers of plywood.
Bond quality was established on the basis of shear tests after water-resistance tests. The obtained results of investigations were compared with properties of plywood produced using amylaceous filler. Nevertheless, regardless of the spread rate, the value of shear strength determined after ageing tests exceeds the values required by the standard EN , i.
Therefore, they meet the requirements of class 2, i. In case of plywood glued with resin modified with amylaceous filler the reduction in spread rate leads to a considerable deterioration of bond quality.
Moreover, in case of plywood glued with resin modified with amylaceous filler, the values of standard deviation determined for the means of shearing strength after the ageing test are remarkably high, which shows a large dispersion of the obtained measurement results.
It arises from the fact that it is difficult to evenly apply the glue to the plywood surface. It is quite significant, as at some point the increased resin load could harm the bond strength as a result of the concentration of internal stresses in the curing process which lead to microcracks even if there is no action of external mechanical forces. Moreover, it is especially important that the addition of 2 PBW of fumed silica per PBW of the resin made it possible to optimize the utilitarian value of the mixed resin, i.
Further reduction of the amount of the applied resin made it more difficult to evenly apply it to the veneer surface. The values of these parameters attained for plywood produced using nano-SiO 2 are comparable with those obtained for the plywood produced with use of amylaceous filler. To determine the effect of substituting amylaceous filler with fumed silica on the class of formaldehyde release in the produced plywood, the flask method was used.
The obtained results correspond with those attained by other authors. The literature review shows that the reduction of formaldehyde release from boards glued with UF resin modified by a small amount of nano-SiO 2 can be ascribed to absorption properties of the well-developed surface of silica Leonovich et al. Researchers also found out that the physical adsorption of formaldehyde is accompanied by the formation of hydrogen bonds between silanol groups on the silica surface and the active groups of the resin and formaldehyde Roumeli et al.
Tannin is extracted from natural sustainable materials. It is widely used to prepare tannin resin adhesives owing to its naturally occurring phenolic structure. This chapter aims to introduce the resources and structures of tannin, existing reactions that are involved in the synthesis of tannin resin, and the applications of tannin resin adhesives in the wood industry. Additionally, the advancements in the research based on the use of tannin resins in manufacturing plywood, particleboard, wood preservation, decoration paper impregnation, structural glulam, impregnated fibers, and other wooden products are reviewed. Herein, the main limitations encountered during the application of tannin resin adhesives and the future key research points are identified. Finally, the potential applications of tannin resin adhesives in the wood industry have been discussed.
E0 Glue - Plywood Adhesive, 200 Kg, Adhesive Grade: Industrial Grade
In fact, it was me that gave it its first scar by rolling a mini filing cabinet from the bedroom to the landing. The Poplar plywood sheets, although a hardwood actually behave more like a softwood, like Pine for example. A lot of people have asked if any of the boards had flipped up or come loose seeing as most of them were only glued down. Any boards that did need a bit of extra help to stay down were pinned with a small nail gun.
Fumed silica as a filler for MUPF resin in the process of manufacturing water-resistant plywood
Geen, Grand Rapids, Mich. Application February 19, ,. In the fabrication of flat plywood panels a number of sheets or layers of veneer are glued together to form a composite panel; each sheet is composed of strips or pieces of veneer, for example, 6 inches wide; a coat of glue is applied to the edges of the strips; the glue being then dried, then moistened with a solution of formaldehyde, and then by me. The handling of the strips for edge-gluing, and the handling of the sheets in assembling the plies, frequently result in splitting or damaging the veneer, not only at their margins, but also in their inner areas. This makes it necessary to temporarily secure together the edges at the split until the assembly of sheets is placed in the press or mold. Heretofore, so far as I am aware, it has been practically impossible to repair these splits except by adhesive tape applied to the exposed faces of the outer layers or plies of the panel or along the margins left for trim from the panel because it was necessary to remove the tape used for such repair from the finished panel. This practice was objectionable because the complete removal of the tape from the exposed faces of the panel was difficult, resulted in marring the outer face of the panel, and the tape left an indentation in the exposed faces produced from the pressure in the press.
The Forests are playing a significant role in the economic prosperity and ecological stability of the country. The Indian Forests faces severe biotic and abiotic pressure leads to shrinking of its geographical distribution and the forest based industries are at the cross roads. This book incorporated the India's Forest and Agroforestry situation and the need for industrial wood plantations. It also comprises the status of various wood based industries like pulp and paper, plywood, matchwood, dendro power, biofuel and the requirement for different raw materials and the associated supply chain management. He is engaged in professional forestry teaching, research and extension for the past 18 years. He is pioneering in conceiving the value chain models for Industrial Agroforestry and promoted industrial wood plantation establishment in association with pulp, paper, match, plywood and biomass power generation industries. He is also pioneer in development of varieties in trees particularly in Casuarina and Melia and transferred these varieties to farm lands through Consortia mode Tree Farming. D Programme in Forestry and has guided over 30 M.
The Plywood Floor – 15 months on…
Versatile Plywood is a layered engineered wood sheet material designed to be suitable for many different jobs ranging from construction to joinery. It is composed of multiple thin, cross grain wooden layers which have been compressed to form one sheet. There is always an odd number of layers so that the board is balanced around its central axis making it less likely to shrink, swell, cup or warp.
Like MDF, plywood comes not only in different thicknesses but also in different grades, so you can choose the right one for your project. Lower grades are used in construction of houses. The higher grades of plywood stain grade, cabinet grade, etc. Unlike MDF, they have consistent wood grain showing and generally lack knot holes and other major imperfections. You can also find veneered plywoods in various wood species Oak, Sapele or Ash for example so you can get the exact look you want for your project. The smooth surface makes it a good choice for simple interior design pieces that will be painted, cabinets, shelving, mouldings etc. Plywood is generally used for doors, stairs, flooring and exterior projects but also bends easily with the grain, so it is often used to create curved surfaces. Moisture also affects the strength of plywood; exterior-glued plywood can be used outdoors, but it works best when the moisture content remains low. George Hill is a leading independent timber merchant and building supplies provider in the North West, with branches in Oldham, Manchester, Bolton and Nelson.
Life Cycle Assessment of Plywood Manufacturing Process in China
Our company offers birch plywood in various species and varieties. All plywood supplied by us are produced on modern European equipment and has international certificates CARB, FSC, etc , confirming the excellent quality and safety of our products. Birch plywood is a multi-layered constructional material, made by gluing birch veneer. The number of layers is usually uneven. The veneer layers are positioned in relation to one another with the directions of the grains crossing to increase the plywood endurance. The furniture industry actively uses INT plywood for manufacturing wholesale and unit packaging.
This work examines the effect of applying fumed silica with nanoscopic-size particles as a filling material for melamine-urea-phenol-formaldehyde MUPF resin in the process of manufacturing water-resistant plywood. Moreover, this paper investigates the possibility of reducing the amount of MUPF resin mixture used in the process of gluing veneer sheets. Based on the investigations into the reactivity, viscosity and durability of MUPF resin mixture containing various amounts of nanofiller, it was found that the optimum amount of silica that can make the resin suitable for gluing sheets of veneer amounts to 2 PBW per PBW of MUPF resin. The gluing properties for thus mixed resin were determined by measuring the contact angle and determining the parameters of its derivatives, which are an additional criterion for evaluating the gluing properties. The experimental plywood manufactured using optimal nano-SiO 2 was tested in terms of bond quality and mechanical properties according to appropriate standards. The investigations prove that it is possible to apply fumed silica as a filling material for the resin in the process of manufacturing water-resistant plywood. Introducing the above-mentioned amount of fumed silica into the resin makes it possible to increase the activation energy of the cross-linking process of MUPF resin and to optimize the process of gluing the sheets of veneer.
Applications of Tannin Resin Adhesives in the Wood Industry
Recommended Thickness Label Figure in brackets is mm equivalent. Exposure 1. Suitable for shelving, factory work surfaces, panelling, signs, built-in storage units. Specially manufactured MDO panels may also be used for concrete forming.
History of APA, Plywood, and Engineered Wood
Plywood is made of three or more thin layers of wood bonded together with an adhesive. Each layer of wood, or ply, is usually oriented with its grain running at right angles to the adjacent layer in order to reduce the shrinkage and improve the strength of the finished piece. Most plywood is pressed into large, flat sheets used in building construction.
European Journal of Wood and Wood Products. This work examines the effect of applying fumed silica with nanoscopic-size particles as a filling material for melamine-urea-phenol-formaldehyde MUPF resin in the process of manufacturing water-resistant plywood.
AkzoNobel is an experienced supplier to the curved plywood industry and provides excellent bonding solutions:. Whether used in hot press or radio frequency press, our UF systems or ultra low emitting formaldehyde ULEF systems offer a very strong glue line to reach dimensional stability and avoid unpleasant spring back. Based on a hard glue line, our bonding solutions prevent surface-crack problems, as well as offering optimal glue consumption to avoid cold-creep.