No abstract

Structural and anatomical models of alder wood have been developed on the basis of technical and physical models of wood. The models enable to solve the problem of penetrating changes in wood texture by combining selective treatment (impregnation) with two wood colouring agents in different directions of anisotropy, followed by uneven pressing. Specimens with the texture of mahogany, rosewood, walnut, etc have been obtained. Alder wood is pressed at an angle of 45° to the radial direction to obtain the texture of mahogany, at an angle of 90° – for a texture of rosewood. At the same time, physical and mechanical properties of modified wood correspond to similar indicators of wood of these species. The study of macro-and microstructure of pressed wood suggests that texture of the obtained material corresponds to the texture of rosewood and mahogany. It is possible to imitate any species of valuable wood using the obtained structural models and the developed techniques.

Cold climate regions need railroad ties with improved operational characteristics during the construction and repair of railroad tracks. The aim of the study is to create a technology and equipment allowing the manufacture of such sleepers. Low-value soft hardwoods, oily antiseptic, and drying press chamber are needed for the production of sleepers with improved performance characteristics. Technological modes for producing sleepers with high performance characteristics of softwood have been tested using the installation which enables to combine technological operations - drying, treatment, and wood pressing. The resulting sleepers can be used in the Extreme North conditions. The half ties have been laid at Chistye Prudy metro station in Moscow, and the ties have been laid at Scherbenka station on the experimental ring of Russian Railways (JSCo «RZD»). The tests have been carried out for four years in underground railway system and for two years on the ring of Russian Railways. The test results have found that wear of modified sleepers and half ties is about 3 times less than wear of pine sleepers and the average service life of sleepers made of modified wood will be about 50 years. An experimental batch is currently being manufactured.

The stocks of bog oak taken from the bottom of reservoirs are increasingly used to preserve growing valuable species of wood, primarily oak. English oak (Quercus pedunculata Ehrh.) is a hard-drying species. Drying modes of oak boards have been well developed for both convection and microwave drying. The interest in bog oak, rose out from water bodies, sharply increased, but it turned out to be impossible to dry it using known methods other than microwave drying. Cracking defects are 70% at a thickness of 30 mm and 100% at a cross section of 60 mm. The article analyzes the results of bog oak drying in laboratory-type microwave chambers. The distance between magnetrons was 0.5 m, and a length of boards was 1.2 m. A semicommercial plant with a loading volume of 2 m3 and total power of 30 kW was used. Total drying time for boards with a total loading volume of 0.2 m3 was from 3 to 5 days. Cracking defects reduced to 20% for a thickness of 30 mm and to 32% for a thickness of 60 mm (with additional treatment by 40% carbamide solution). Board warping was not noticed.

No abstract