Volume 50, Nº 2 (2018)

Carbon—silicon-carbide fibers were produced from cellulose and triethoxyvinylsilane and spun using the solid-phase NMMO-process. Scanning and transmission electron microscopy studies, energydispersive x-ray spectrometry, and x-ray structure analysis of composite carbon fibers established and identified the structure and morphology of carbon fibers that varied from an isotropic shell to regularly organized lamellae of graphite-like layers of the fiber core. Distributions of chemical elements were plotted. The nano-sized dimensions of silicon-carbide regions in the carbon fibers were determined.

Test results for the main properties of prepregs and carbon plastics based on a new generation of polymeric binders, i.e., highly flexible epoxide binder VSE-1212, and Russian woven carbon reinforcing fillers designed to fabricate PD-14 engine cowl flaps, pylon shrouds, and reverse device fittings, and also for primary and secondary constructions for modifications of promising MC-21 airplanes, etc.

Modification of fibrous ion-exchange composites by adding ultradisperse metal particles is a promising method for producing composites with high operating characteristics. Modifiers of Ni and Fe in polycondensed Polikon K composite act as additional linking centers, alter considerably its structure, and improve the property set.

We consider the influence of frictional forces between warp and weft yarns on the resistance of the fabric. We have established that when the fabric is stretched, the strain distribution is not uniform over the length of the sample. We have found that the major portion of the strain occurs in the section of yarns between their overlaps with weft yarns.

A design of the filter element for purifying liquids to remove mechanical impurities is proposed, obtained by winding two threads on a perforated rigid rod. The design ensures improved filtration quality due to the preservation of the uniform structure of the filtering layer, the reduction of its compaction and deformation during the filtration process, as well as the increase in the distance overcome by the liquid inside the filtering layer.

An analysis of different methods of managing electric fork lifts is carried out and the minimally necessary number of electric motors and their types are determined. An algorithm for serial introduction of electric motors into operation is developed and a method of control by means of a frequency regulator is determined.

Air permeability of processed nonwoven needlepunch cloth fabricated from fibers of various linear densities and a bicomponent fiber was studied. The processing regime and an increase of bulk density were shown to affect the cloth air permeability. A model for predicting air permeability was developed based on a complex structure parameter.

The effects of the number of layers, indenter speed, and moisture content of ballistic fabrics on the cutting load of a single-edged knife were studied. The experimental results yielded single-factor models that could predict the cutting load for ballistic fabrics.

Methods for mathematical modeling of deformation-relaxation processes of aramid textile materials are described. It is shown that the increase in the competitiveness of these materials is closely tied to qualitative analysis methods of their operational-consumer and functional properties.

The effect of the metal halide FeCl₂ and its hydrate on increasing the intensity of corrosion-mechanical wear of the parts of gear metering pumps during the dosing of spinning solutions for spinning aramid fibers was studied. One of the ways to reduce the intensity of wear and, correspondingly, increase the life of metering pumps by manufacturing pumps of a new design with a casing made of a composite material with a polymer matrix is considered.

The principal features of a controlled electromechanical complex from the point of view of energy indicators are considered. The problem of balancing output through the production of a smooth feed layer as well as variant solutions of the problem (increasing the velocity conditions of the operations, replacing the linkage control system used to fill the hopper by an electromechanical system) is stated. Cyclic operation of the self-weight as the principal tool of the hackling machine is described together with its technical parameters. Simulation of the operating regimes of the self-weight is performed and relationships that characterize the operation of its basic parts are obtained. The resulting relationships are analyzed and a description of the operation of different parts of a line for the production of bulk nonwoven filament based on the Befam CU-311 hackling machine is considered.