The concept of quality in the minds of Soviet and Russian people is inextricably linked with the concept of GOST. Requirements, imposed by the standard to quality of production, does not remain constant, but change in accordance with the level of development of science, technology and best practices. The article considers dynamics of changes of requirements of GOST 10632 "Chipboards. Technical conditions" to the quality of chipboards in the last 40 years. The author analyzes the wording of this standard, approved in 1977, 1989, 2007 and 2014. For specified period of time the labeling of the plates P-A and P-B to P1, P2 has changed, which is related to the harmonization with foreign standards. In the last edition of the GOST 2014 plates have no restrictions on size, so as to replace presses periodic action, which have specific dimensions of the heating plates of the press, presses of continuous extrusion come. The same situation is with the densities of boards, the manufacturer sets its value, but the strength of the plates shall conform to the requirements of the standard. Although, strength characteristics (ultimate strength in tension perpendicular to the plate and the ultimate strength in static bending) are reduced with each new edition of GOST. Tightening of the requirements has occurred to the sanitary and hygienic indicators of chipboards. The content of free formaldehyde has decreased from 10 to 4 mg per 100 g of absolutely dry plate. To obtain competitive boards of E0 emission class Russian chemical industry needs to develop a large amount of resins with low content of free formaldehyde.
As a result of work it is established that decrease in temperature of a veneering with 85 to 60 0C positively influences reduction of a deflection of boards. Use of polyvinyl acetate disper-sion of various viscosity of essential influence on a deflection and durability of glue connection doesn´t render. Taking into account a deflection and durability of glue connection the best results are received at a veneering of a furniture board with use of high-viscosity dispersion at a temper-ature of 60 0C, pressure of 0.7 MPa and duration of endurance in the press of 52 seconds.
One of the main objectives of the enterprises for production of furniture is decrease in a material capacity of production and as a result decrease in its prime cost. Producers of kitchen table-tops for this purpose pass to production of table-tops of the combined design, replacing thick wood-shaving plates 25, 38 mm thick, with thinner 16 mm.For maintenance of more massive appearance of such table-tops to thin wood chipboard in the longitudinal direction at the edges of a board paste longitudinal strips from chipboard. The economy of material can lead to a deflection, the received table-tops. In this work the deflection of table-tops of the combined design was investigated. For studying of the reasons of emergence of a deflection and ways of its decrease the samples received in laboratory and working conditions were investigated. For pasting of boards from chipboard the paper and layered plastic used glue on the basis of polyvinyl acetate dispersion and the combined glue with various ratio of urea-formaldehyde resinand polyvinyl acetate dispersion. At the first stage defined a deflection of not revertedwood-shaving plates. Then controlled change of a deflection after gluing of plastic, paper from the back (and, paper and plastic made a veneering consistently and at the same time), after gluing of levels from chipboard. The deflection was defined in various directions of a furniture board in dynamics. Determined durability of gluing of plastic by above-mentioned glues. As a result of work it is established that the veneering of the front and reverse parties of plates in a hot press needs to be made at the same time. By production of the combined design of table-tops it is more expedient to use pure polyvinyl acetate dispersion. Durability on a plastic separation from wood-shaving plates is higher when using of the mixed glue on the basis of polyvinyl acetate dispersion and urea-formaldehyde resin.
Growth rates of production of furniture in our country increase every year. And as the statistics, generally due to production of furniture from slabby glued materials, such as a chipboard, fiber board of average density, plywood shows. Apply to an upclassing of a surface of boards of slabby materials most often PVC films, the decorative paper and layered plastic and much less often the planed interline interval and an interline interval began to use a fayn-line. It is connected by that at a veneering a planed interline interval one of defects of a veneering – infiltration of glue on a front surface of a board very often comes to light. Ways of elimination of such defects aren´t present and therefore the spent materials simply are utilized and hit the pocket the producer. To avoid these risks the producer simply refuses use of similar materials. Our research was reduced increasing viscosity of glue and by that to exclude possibility of its infiltration on a front surface. For this purpose we suggest to enter into working solution gluing a filler – grinding dust. Use of grinding dust in the form of a filler at a veneering of boards allows to solve at once some problems: to use at a veneering of boards low-toxic urea-formaldehyde resin (today in production of products from wood generally urea-formaldehyde resin with a carbamide ratio to formaldehyde 1:1.5 are used), to increase durability of pasting of a basis and facing materials, to reduce marriage percent due to infiltration of glue on a front surface. Results of researches showed that it is possible to use low-toxic urea-formaldehyde resin where the filler in the form of grinding dust will be added to a compounding of glues at a veneering of boards. Optimum values of quantity of a filler from the square of infiltration of glue at a front surface and durabilities of gluing of facing layers to a basis were established.
The task of the experiment was to clarify the standard modes of bonding plywood using in their produc-tion low toxic urea-formaldehyde resins, and obtain the required bond strength, as well as statistical anal-ysis of the results of research in order to obtain regression equations. The results showed that the bonding strength of plywood on low toxic resins is lower than on resins with high formaldehyde content. To en-sure the preservation of strength is possible only due to increased consumption of adhesive and duration of bonding.
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