In this paper a tensile characteristics of filament-wound glass fiber-aramid fiber/epoxy resins hybrid composites and glass fiber-two carbons fibers/epoxy resins hybrid composites are presented. Basic terms about hybride composite materials (origin, reasons for manufacturing, advantages, definitions, levels of hybridization, modes of classifications, types, categorization, and possible interactions between constituents) and used reinforcements and matrices are described. For a manufacturing of NOL rings four reinforcements (glass fiber, polyamide aromatic fiber and two carbon fibers) and two matrices (high and moderate temperature curing epoxy resin system) are used. Based on experimentally obtained results, it is concluded that hybride composite material consisting of carbon fiber T800 (67 % vol) and glass fiber GR600 (33 % vol) impregnated with epoxy resin system L20 has the highest both the tensile strength value and the specific tensile strength value. The two lowest values of both tensile strength and the specific tensile strength have hybrid material containing aramide fiber K49 (33 % vol) and glass fiber GR600 (67 % vol) and epoxy resin system 0164 and hybrid NOL ring with wound carbon fiber T300 (33 % vol) and glass fiber GR600 (67 % vol) impregnated with the same epoxy resin system. This investigation pointed out that increasing the volume content of aramide fiberK49, carbon fiber T300 and carbon fiber T800 in appropriate hybrid composites with glass fiber GR600 increases both the tensile strength value and the specific tensile strength value and decrease the density value, no matter the used epoxy resin system.

Practical and realistic approach for a successful use of filament wound filter housing based on bisphenol A polyester resin for purification of highly corrosive contaminated solutions is presented in this paper. Filament winding technology and basic terms about polyester and polymeric composite materials are described. Data about modes of producing neat (no reinforced) bisphenol A polyester resin specimens and composite material specimen, based on mentioned resin and glass fiber, are presented. Neat resin specimens were exposed to the single influence of aqueous solution of calcium hypochlorite, of sodium hydroxide, of sulphuric acid, of citric acid and liquid detergent for a period of 360 hours each, separately, and to the cumulative influence of all mentioned aqueous solutions for in overall period of 1440 hours. Tested properties of these specimens (mass change, hardness and impact resistance) showed that there is no negative influence on neat bisphenol A polyester resin quality. Filament wound composite reinforced glass fiber/bisphenol A polyester resin-based rings and cylinders were exposed to the influence of calcium hypochlorite aqueous solution for 1128 hours. Results of testing mass change, tensile breaking force and tensile strength of composite reinforced rings and hydraulic burst pressure of composite reinforced cylinders indicated that these specimens have high resistance to mentioned purification agent. It is concluded that the filter housing for purification of highly corrosive contaminated solutions can be produced by filament winding technology using bisphenol A polyester resin and glass fiber.

In this paper, investigation of tensile testing for specific assemblies of two elements, jointed by mechanical fasteners, are presented. One element is a specific small diameter tube. This element is produced by filament winding technology using glass fiber impregnated with polyester resin. Another element is cylindrical steel part, obtained by standard technology. Basic data about composite materials and mechanical fastening are presented. Pins and rings were used as mechanical fasteners. Data of tubes preparation and assembling glass fiber/polyester resin tubes and cylinder with pins and rings are presented. The assemblies specific composite material parts/metallic parts jointed by fasteners were exposed to the action of axial tensile stress. A tensile breaking force of the assemblies was determined and the influence of pins number to tensile breaking force was presented. A failure mechanism of specific composite tubes fastened with pins and rings is described

This research work focuses on the development of extrusion of non-standard PVC pipe and characterization of the obtained product. The extrusion technology and poly(vinil chloride) polymer are described in shortest. Non-standard extruded PVC pipes were developed in three phases. Characterization of the non-standard extruded PVC pipes includes testing of nonstandard properties, standard PVC pipes characteristics and additional properties. Non-standard properties include specific dimensional (non-standard outside diameter and inside diameter), hydraulical (hydraulic burst pressure in a short period of time in water-air and water-water experiments) and mechanical (external radial compressive force and internal tensile radial strength) characteristics. The standard extruded PVC pipes characteristics were, also, determined (density, visual appearance, Vicat softening temperature, dimensional longitudinal stability and resistance to external blows and to dichloro methane). Additional tested properties are resistance to severe external blows, dimensional radial stability, impact resistance and hardness. Deliberately produced damage has no negative effect on pipes' hydraulic and mechanical characteristics. Based on presented results concerning the non-standard, standard and additional properties and deliberately produced damage, it is concluded that a high quality non-standard extruded PVC is developed.

In this paper the details about manufacturing of multilayer cylinders consisting of metal liner (obtained by standard machining procedures) and polymeric composite material (produced by filament winding technology) are presented. For multilayer cylinders manufacturing three types of steel liner (еach liner type has three different wall thicknesses) are used. Glass fibers impregnated with polyester resin were wound at the outer surface of the mentioned nine liners and so the manufactured multilayer tubes were exposed to the action of internal hydraulic pressure with measurement of deformations in radial direction. Two groups of the results, obtained during hydraulic testing of multilayer cylinders, were presented: one group represents elastic characteristics, i.e. the properties of the examined tubes at the elastic limit, and another group represents the final properties, i.e. the characteristics of the tested tubes at the moment of burst. Calculation of the pressure at the elastic limit, by a simplified procedure, was done. By comparing the value of experimentally tested pressure at the elastic limit and the value of calculated pressure at the elastic limit, it was concluded that there is a good agremeent between these two data. Values of experimentally tested radial deformations at the elastic limit of external surface of multilayer tubes and values of this parameter obtained by calculation of simplified model, are, also, meaningfully approximate. Based on the experimental data, an influence of a pathway from the lower outside liner diameter to higher outside liner diameter was established, and, also, an influence of liner wall thickness on characteristics of multilayer tubes, which were exposed to the action of internal hydraulic pressure. Based on the introduced parameter hydraulic burst pressure/mass ratio, it was concluded that a higher presence of polymer composite material has positive influence on hydraulic burst pressure (increasing) and mass (decreasing) of the mentioned multilayer tubes.