Author: Viktor Savov
Articles
- EFFECT OF SOME TECHNOLOGICAL FACTORS ON PHYSICAL PROPERTIES OF MEDIUM DENSITY FIBREBOARD MADE OF HARDWOOD SPECIES
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Summary
On the basis of performed literature overview and analysis of the effect of production modes on physical indices of fibreboards, following variable factors were determined: pressing temperature, board thickness and binder content.
In this paper, the results of the performed analytical and empirical investigations with respect to the effect of pressing temperature, board thickness and binder content on physical properties of MDF-type boards (medium-density fibreboards manufactured after the dry method) made of hard hardwood species are presented. Regression models showing the effect of variable factors on board indices were derived. The changes in the values of those indices in case of combinations of levels of production factors were examined. Analysis of the result was made, with the respective conclusions having been drawn.
Keywords: MDF, mechanical indices, hard hardwood raw material, technological factors
- EFFECT OF PRESSING PRESSURE ON INDICES OF FIBREBOARDS MANUFACTURED FROM WOOD OF HARD BROAD-LEAVED SPECIES
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Summary
The main factor defining the performance of the hard thin FBs is the pressure applied in the process of piezothermal treatment. In order to manufacture a product designed by engineering, the pressing pressure should be with a specific value determined in advance. The latter is in correlation dependence on the tree species, the characteristics of the wood-fibre mass and of the wood-fibre carpet. Determining, out of these factors, is the resistance that the carpet shows under the applied external load, with it depending mainly on the characteristics of the mass and, to a determining degree, on the tree species used for the manufacture of the boards.
In this paper, an investigation on the effect of pressure during manufacture of thin FBs on the basis of beech and cerris oak wood is presented. Derived are the main dependences of the performance of FBs on the factors examined in case of application of the methods of regression analysis, with use of the least squares method. Established are the optimum values of pressure depending on the thickness of the boards and the design thickness set.
Keywords: FBs, hard wood-based raw material, piezothermal treatment, thickness, density
- STUDY ON INFLUENCE OF RESIN CONTENT OVER MAIN PROPERTIES OF DRY-FORMED HARDBOARDS
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Summary
Fiberboards are homogeneous wood-based composite material with dispersion phase – wood fibers and matrix of adhesion and cohesion binders formed between the elements. The importance of this two binder types for board’s properties depends from manufacturing processes. The adhesion binders have main significance at dry-processes manufacturing.
At the report is presented study on influence of resin content over main properties of dry formed hardboards, produced from hardwood on the base of phenol-formaldehyde resin. For the purpose is implemented experiment in laboratory conditions. The correlation coefficient and functional subjections of fiberboard’s properties from resin content are determinate. It is conducted analyze of the results and proper conclusions are made.
Keywords: dry-formed hardboards, resin content, phenol-formaldehyde resin, correlation