International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Effects of various fire retardant (FR) chemicals on mechanical and fire properties of plywoods were investigated. Boron compounds such as, borax and boric acid; and phospate compounds such as, monoammonium phosphate and diammonium phospahate were used as fire retardant chemicals in the plywood panels. An exterior liquid phenol formaldehyde resin with 47% solids content was used as adhesive. The 2.2 mm thick Tetraberlina wood veneers were treated with the liquid solution of FR chemicals. The plywoods having 5-layers were produced from the treated wood veneers. The mechanical properties of the plywoods produced with treated veneers was found to be lower than that of the control group. Among the treated plywoods, The plywoods treated with borax had highest mechanical properties, followed by diammonium phosphate (DAP), monoammonimum phosphate (MAP), and, boric acid, respectively. The FR chemicals improved the fire resistance of the plywoods. The chemicals showed individually different effects related to improvement of fire resistance of the panels. For example, the OSB panels treated with diammonium phoshate were the latest ignited group (52.8 s) which were followed by the panels treated with boric acid (49.2 s), borax (44.5 s), and monoammonium phosphate (41.2 s), respectively. As compared to the control group (7.5 cm), the plywoods treated with borax (3.6 cm) had the shortest flame length after burner was turn off, followed by diammonium phosphate (4.2 cm), boric acid (5.1 cm), and monoammonium phosphate (5.8 cm).

The article presents the results of a study of the influence of technological parameters of FDM-printing of samples based on aliphatic polyamide on the deformation and strength characteristics of products based on it. The anomalous nature of the increase in the tensile strength during the destruction of samples obtained by increasing the print speed is shown. A decrease in the strength of the samples was noted with an increase in the number of simultaneously printed products. The main factor determining the strength characteristics of FDM products is interlayer autohesion. The need for the use of materials science solutions that contribute to an increase in interlayer interaction in products obtained by layer-by-layer deposition is indicated.

This publication traces the peculiarities of metal powder production for powder metallurgy. Of the variety of methods, particular attention is paid to those that are most widely used in practice – reduction and powdering methods. Metallurgical photo of iron powders obtained by different technological processes are presented, as well as tables with the basic technological properties of iron powders obtained by reduction and powdering.

The objective of the present study was to investigate the effect of adhesive type on physical and mechanical properties of particleboard. Three types of adhesives, urea-formaldehyde, melamine-urea formaldehyde adhesive, and acrylic adhesive, were used in the production of lab scale particleboards with three layers. The particleboards produced with the acrylic adhesive had the best physical and mechanical properties, followed by MUF adhesive, and UF adhesive, respectively. The lowest formaldehyde emission was observed for the acrylic bonded particleboards, followed by MUF, and UF adhesive bonded particleboards, respectively. Based on the findings obtained from the present study, the acrylic adhesive can be efficiently used in the production of particleboard.

The objective of the present study was to investigate the effect of adhesive type on physical and mechanical properties of particleboard. Three types of adhesives, urea-formaldehyde, melamine-urea formaldehyde adhesive, and acrylic adhesive, were used in the production of lab scale particleboards with three layers. The particleboards produced with the acrylic adhesive had the best physical and mechanical properties, followed by MUF adhesive, and UF adhesive, respectively. The lowest formaldehyde emission was observed for the acrylic bonded particleboards, followed by MUF, and UF adhesive bonded particleboards, respectively. Based on the findings obtained from the present study, the acrylic adhesive can be efficiently used in the production of particleboard.

In this paper, local post weld heat treatment (LPWHT) effects on the metallurgical and mechanical properties of high frequency electric resistance welded (HFERW) steel pipes were investigated. Local post weld heat treatment (LPWHT) of the welded joint was carried out by an induction heating device which selectively heat only the weld area from the outside surface of the welded steel pipes. Optical microscopy, tensile testing, Charpy-V-notch testing, hardness testing and flattening testing were used to evaluate local post weld heat treatment (LPWHT) effects on the metallurgical and mechanical properties of high frequency electric resistance welded (HFERW) steel pipes.

The waste powder produced during the manufacture of marble, which is presently mostly discarded in landfills, has the potential for higher-valued usage. Recycling marble waste powder will contribute to the protection of nature as well as economic gain. The goal of this study is to investigate the potential use of marble waste powder as filler in the thermoplastic composites with wood. Thermoplastic composites were manufactured by adding marble factory waste powder and wood powder in different ratios to polypropylene (PP). Maleic anhydride grafted polypropylene (MAPP) were used as coupling agent to improve interfacial adhesion between hydrophilic wood–fibers and hydrophobic polypropylene. The waste marble powder and wood powder were mixed by weight of with polypropylene in the percentage of 0%, 10%, 20%, 30%, 40%, and 50%. Physical and mechanical tests were performed on the specimens prepared from the thermoplastic composites. Although mechanical properties of the composites decreased with increasing content of the marble powder, the water absorption of the composites significantly decreased with increasing content of the marble powder.