Method of determining degree of impregnation of carbon fibre braids with pitches and device for its realisation
SUBSTANCE: invention relates to field of producing carbon-carbon composite materials for various purposes, and is intended for comparative characteristic of impregnation of carbon fibre (CF) braids with melts of pitches, and can be used in improvement of technologies of producing carbon-carbon composite materials, possessing various properties, by modification or replacement of pitch binder and/or carbon fibre, for instance, in research laboratories, in particular, in carrying out laboratory work. To determine degree of impregnation of carbon fibre braids with pitches, carbon fibre braid is placed into glass tube in such a way that the end of braid protrudes from glass tube, and carbon fibres in braid are oriented along glass tube axis, with braid thickness being selected in such a way that it tightly fits glass tube, protruding end of carbon fibre braid is brought in contact with melted pitch and keep in such position, after which carbon fibre braid is extracted from tube and height of impregnation of carbon fibre braid with pitch is determined.
EFFECT: simplification and acceleration of determination are achieved.
1 ex, 3 dwg
The invention relates to the production of carbon-carbon composite materials for various purposes, is intended for comparative evaluation impregnation of bundles of carbon fibers melts Pekov and can be used in the development of production technology of carbon-carbon composite materials having different properties through modification or replacement of the pitch binder and/or carbon fibers, for example, in research laboratories, in particular, when conducting laboratory work.
Carbon fibers are characterized by a unique combination of physical, mechanical and chemical properties, combining high strength and chemical inertness, so you can use them to create composite materials not only common, but also aviation and space purposes. The strength and reliability of such materials, as well as simplification of the technological scheme for obtaining one depends on the nature of the interaction at the interface of carbon fibre/matrix. Functionalization of carbon fiber, modified binders, etc. promotes adhesion of carbon fibers to the matrix and to improve the mechanical properties of the material obtained.
One of the factors determining the strength of a composite material comprising a reinforcing component is the form of bundles of carbon fibers and polymer matrix in the form of pitch, is the ability of the binder to wet the carbon fiber, in other words, the affinity of carbon fiber and pitch. Wetting, in turn, determines the degree of impregnation of the fiber filler binder in the molding process and the uniformity of the material.
There is a method of determining the wetting of the carbon fibers of pitch, which was performed as a plate, Wilhelmi on the power tensiometer (Shornikova O. N. and other Wetting of the carbon fibers by the molten coal tar pitch // Chemical fiber. - 2012. No. 4. - S. 64-68). This method is adopted for the prototype. The essence of the method records Wilhelmi consists in immersing the plate with known geometrical parameters in the test fluid: when immersing the plate into a liquid it operates eject force F, which depends on the depth of immersion of the plate in the liquid. At the first stage of work was measured boundary angles of wetting of the carbon fibers of model fluids, samples monofilaments were placed in a hollow cylindrical holders, fixed with wire so that the length of the free end of the fiber not over 5 mm Holder secured on the scales and the sample was brought into contact with the model fluid. The measurements were carried out for 10 samples of fibers of the same type, within each measurement was performed 5 cycles of immersion/and the inclination of the fiber. In each cycle was recorded curve wetting - dependence of the force acting on the sample from the depth of immersion. Then the expected equilibrium wetting angles, the polar and dispersive components of the free surface energy of the fibers. Then determined the characteristics of the pitches. For this sample pitch was placed in a beaker with a diameter of 70 mm and height of 40 mm, so that the glass was half full. The glass electrode was placed in a thermostatted cell with a temperature of 160°C. Next, the measured surface tension of melts of pitches by the method of the rings due Nui. For each sample was performed 10 measurements. Next was measured wetting angle Teflon plates molten pitch was calculated polar and dispersive components of the molten pitch. For each sample spent at least 5 measurements. Between measurements peck thermostatically 10 minutes with the lid closed.
This technology determine the wetting of the carbon fibers of pitch is very difficult, time consuming and requires a lot of time measuring process and the decryption process of the data. Another disadvantage of this method lies in the complexity of its hardware design.
In addition, the measurement of the wetting of the fibers of a polymeric binder (pitch) directly is not always possible due to the small diameters of the monofilaments and the viscosity of the binder.
The objective of the invention is the tsya simplification and acceleration of the process of determining the degree of impregnation of carbon fibers by pitches as well as simplifying the equipment to determine the degree of impregnation of carbon fibers by pitches.
The technical result is achieved by a method for determining the degree of impregnation of bundles of carbon fibers pitches, which is characterized by the fact that the harness carbon fiber is placed in a glass tube so that the end of the harness was made of a glass tube, and carbon fiber in the bundle are oriented along the axis of the glass tube, when the thickness of the harness is chosen so that it is tightly held in a glass tube, the protruding end of the bundle of carbon fibers is brought into contact with the molten pitch and survive in this position, then harness carbon fiber extracted from the tube and determine the height of the impregnation of the bundle of carbon fibers peck.
Technical result is achieved by setting to determine the degree of impregnation of bundles of carbon fibers pitches, which can be carried out the above method and which contains the furnace, the base with the possibility of placing it in an oven, a tray mounted on the base, and a holder for at least one vertically installed glass tube, located at the base on the tray with a vertical reciprocating movement.
The foregoing features and advantages of the invention will be clear from the following description of preferred examples with reference to the accompanying drawings, on which the same elements are denoted by identical positions:
in Fig.1 shows a diagram of the installation to determine the degree of impregnation of bundles of carbon fibers pitches in accordance with the present invention;
in Fig.2 is a diagram of a base installed on the tray and a holder in the original position in accordance with the present invention;
in Fig.3 is a diagram of a base installed on the tray and a holder in position when the protruding end of the bundle of carbon fibers is lowered into the molten pitch, in accordance with the present invention.
The basis of the method of determining the degree of impregnation of bundles of carbon fibers pitches in accordance with the present invention based on a capillary liquid (solution, melt) in the region between the carbon fibers collected in the harness. For carrying out the proposed method uses at least one glass tube 1, which is placed in harness 2 carbon fiber. The thickness of the wiring harness 2 is chosen so that it is tightly held within the glass tube 1. Carbon fiber tow 2 is oriented along the axis of the glass tube (almost parallel). The free end of the harness 2 carbon fiber, the speaker of the glass tube 1, is brought into contact with the impregnating liquid - molten pitch 4 and videris who are in this position for a fixed period of time. Because carbon fiber caused sizing, and there are defects, what would be the dense nor was packing carbon fiber bundle 2, there is a long and narrow space. If carbon fiber is wetted by molten pitch 4, due to the effect of capillary suction it will rise along the carbon fibers and fill the distance between them. If the packaging harness 2 carbon fiber is not dense, then the gravitational force exceeds the force of capillary suction, and the molten pitch will not impregnate harness carbon fibers. Then harness 2 carbon fiber removed from the glass tube 1 and determine the path of the molten pitch 4 in the Central part of the harness 2, i.e., the height of the impregnation harness 2 carbon fiber peck 4.
The above-described method can be implemented at the facility to determine the degree of impregnation of bundles of carbon fibers pitches, which contains the furnace 5 and the base 6, which is located with the possibility of placing in the oven 5. As the furnace 5 can be used in the drying Cabinet or muffle furnace, providing temperatures up to 350°C. On the basis of 6 mounted bath 7 for pitch 4. Based 6 on the tray 7 is located with the vertical reciprocating movement of the holder 8 for at least one vertice is Ino installed glass tube 1.
Work on the installation to determine the degree of impregnation of bundles of carbon fibers pitches as follows.
Carbon fiber is cut the same length and put together, forming wiring harness 2. Received the harness 2 is placed in a glass tube 1 so that the end of the harness 2 protrudes from the glass tube. 1, and the carbon fiber bundle 2 were oriented along the axis of the glass tube 1, when the thickness of the harness 2 is chosen so that it is tightly held within the glass tube 1.
In the tub 7 fall asleep peck 4 and sets over it the holder 8 for the at least one glass tube 1. The holder 8 is fixed vertically at least one glass tube 1 so that the protruding end of the harness 2 carbon fiber was at some distance from the level of the pitch.
Base 6 with a tray 7, is filled with pitch 4, and the holder 8 with at least one glass tube 1 with a bundle of 2 carbon fiber is placed in a furnace 5, heated to a temperature of 80°C. above the softening point of pitch (~190°C). After melt pitch 4 additionally incubated for 30 minutes. After that, the holder 8 is lowered to such a level that the protruding end of the harness 2 carbon fiber come into contact with the molten pitch 4, and the edge of the glass tube 1 is positioned above the level of pitch 4. The holder 8 in this is ulozhenie fix and maintain. Then, the base 6 is extracted from the furnace 5, and the holder 8 is raised to its original position. After cooling harness 2 carbon fiber removed from the glass tube 1 and determine (e.g., tactile) height impregnation harness 2 carbon fiber peck 4.
The described method is proposed for comparative evaluation impregnation of bundles of carbon fibers melts Pekov, the results of which you can use when developing technologies for the production of carbon-carbon composite materials depending on their mechanical and operational properties through modification or replacement of the pitch binder and/or carbon fiber.
Setting to determine the degree of impregnation of bundles of carbon fibers pitches contains:
the base 6 is located with the vertical reciprocating movement of the holder 8 for glass tubes 1;
- glass tube 1 with an inner diameter of 8 mm (5 pieces);
- bath 7 for melting pitch 4;
oven 5, providing temperatures up to 350°C.
Determination of the degree of impregnation of bundles of carbon fibers pecks at the facility was carried out as follows.
1. Sample preparation carbon fiber.
Carbon fiber cut length 100 mm and folded together into bundles 2 so that the resulting line is Naya density was 27,000 Tex.
The obtained carbon fiber bundles were placed in a glass tube 1 so that the end of the wiring harness 2 is performed from the side of the glass tube 1 at 10-13 mm. the ends of the wiring harness 2 podrachivala with scissors.
2. Preparation of the installation to determine the degree of impregnation.
In the tub 7 bombarded peck 4 and set the holder 8, which is secured 5 glass tubes 1 with a bundle of 2 carbon fiber so that the distance from the level of the pitch until the end of the harness 2 carbon fiber was 15-20 mm. Original position before performing the assay shown in Fig.2
3. Carrying out the determination of the degree of impregnation.
Base 6 with a tray 7 and the holder 8, in which is placed a glass tube 1 with the wiring 2 carbon fiber was placed in a furnace 5, heated to a temperature of 80°C. above the softening point of pitch (~190°C). After melt pitch 4 installing optional kept for 30 minutes. After that, the holder 8 is lowered to such a level that the ends of the wiring harness 2 carbon fiber were immersed in molten pitch 4, wherein the side of the glass tube 1 is positioned above the level of pitch 4 1-2 mm (see Fig.3). The position of the holder 8 recorded and kept for 2 hours. Then the base 6 was removed from the furnace 5 and the holder 8 is raised to its original position (see Fig.2).
After cooling, the wiring 2 carbon fiber was removed from the glass tubes 1 and defined (tactile way) height impregnation harness 2 carbon fiber peck 4.
This example confirms that the proposed method and installation allow you to simplify and accelerate the process of determining the degree of impregnation of bundles of carbon fibers pitches, as well as to simplify the apparatus and equipment and to reduce the operation of the decoding of the received data.
The above-described embodiment should in all respects be regarded as merely illustrative and not causing any restrictions. Therefore, can be used in other embodiments of the present invention and examples of implementation, which does not exceed the limits described here are essential attributes.
The method of determining the degree of impregnation of bundles of carbon fibers pitches, characterized in that harness carbon fiber is placed in a glass tube so that the end of the harness was made of a glass tube, and carbon fiber in the bundle are oriented along the axis of the glass tube, when the thickness of the harness is chosen so that it is tightly held in a glass tube, the protruding end of the bundle of carbon fibers is brought into contact with the molten pitch and survive in this position, then harness carbon fiber extracted from the tube and determine the height of the impregnation of the bundle of carbon fibers peck.
SUBSTANCE: method involves cutting a sample for analysis and analysing its chemical composition, from which the rubber brand is determined. The sample is cut such that it has pre-decomposition zones. Chemical composition is analysed from a fracture in the sample by X-ray spectral technique on a scanning electron microscope with an energy-dispersive spectrometer. The obtained data on chemical composition of the sample are compared with chemical composition of a known rubber brand or a rubber brand used as a reference.
EFFECT: high accuracy and objectivity of determining a rubber brand.
3 ex, 1 tbl, 2 dwg
SUBSTANCE: method involves titration of a suspension with a solvent which is soluble in water and dissolves the suspended resin-like substance until reducing light scattering, which is determined either visually or using optical devices which enable to measure the amount of light passing through the liquid.
EFFECT: rapid estimation of the amount of resin-like substance suspended in water.
SUBSTANCE: apparatus has a clamp mechanism for holding material, an indenter for loading with possibility of measuring its displacement and recording information into a processor. A sensor is built into the indenter, said sensor being sensitive to the spectrum of acoustic emission generated by a sample upon change of deformation characteristics thereof. The clamp mechanism is in form of two coaxially placed cups with built-in heating elements with a controlled temperature range and a sensor for said temperature.
EFFECT: broader technological capabilities of the apparatus and high measurement accuracy.
SUBSTANCE: before testing in a heat chamber, samples of polymer materials are activated with UV radiation in the 248-365 nm wavelength range for 3-30 minutes with radiation power density of 1-15 mW/cm2. Analysis of volatile organic compounds is carried out while comparing the obtained chromatograms of gas samples collected from the heat chamber when testing samples of polymer materials with selected additives based on nanostructured bentonite powder and nanostructured bentonite powder intercalated with metal ions - magnesium (Mg2+ ), scandium (Sc3+), chromium (Cr3+), manganese (Mn2+), iron (Fe2+), cobalt (Co2+), nickel (Ni2+), copper (Cu2+), zinc (Zn2+), tin (Sn2+), cerium (Ce3+) or a mixture of bentonite powders intercalated with ions of said metals. The results of comparing chromatograms of gas samples are used to evaluate the effect of nanocomponents on the predicted sanitary-chemical properties of the designed polymer materials.
EFFECT: realisation of the present invention widens technological capabilities and increases reliability of results of evaluating the effect of modifying mineral nanocomponents on predicted sanitary-chemical properties based on release of volatile organic compounds from the designed polymer materials.
8 cl, 7 ex, 2 tbl, 4 dwg
FIELD: textile, paper.
SUBSTANCE: at the first stage the organoleptic analysis of tested samples is carried out. At the second stage the microscopic analysis of the material structure is carried out. At the third stage the chemical analysis of the tested samples is carried out by means of their treatment with an organic dissolvent selected from the group: butyl ether of acetic acid, dimethylketone, dimethylformamide, tetrahydrofuran, furfural, cyclohexanol at the ratio of sample-dissolvent equal to 1:(10-15) at the boiling temperature of the selected dissolvent for 20-30 minutes. If a sample has dissolved fully, the conclusion is made that is pertains to leather-like materials, and if a sample has not dissolved, it is identified as leather.
EFFECT: accurate and reliable recognition of leather from leather-like materials.
2 cl, 3 ex
SUBSTANCE: method involves pre-activation of surfaces of an article and a film. The article then pressed to the surface of the film made from non-light-stabilised polyethylene and then exposed to UV radiation until a brittle layer forms.
EFFECT: formation of a coating on an article, which is adhesively bonded to the surface of the article.
SUBSTANCE: method involves providing a specimen, irradiating the specimen with a predetermined spectrum of electromagnetic radiation, recording the interaction between the specimen and the electromagnetic radiation in a data packet and determining at least one characteristic parameter in the recorded data packet. Radiation intensity values assigned to different areas of the surface of the specimen, where said radiation interacts with said surface areas, are recorded in the data packet. The determined characteristic parameter describes air content in the specimen and/or resin content in the specimen. The assigned intensity values coinciding with a predetermined intensity range are added together to determine the air content and/or the resin content in the specimen. Analysis can also be performed to determine resin distribution and/or air distribution in the sample and homogeneity of distribution of assigned intensity values coinciding with the predetermined intensity range with respect to different areas of the surface.
EFFECT: possibility of analysing specific characteristic parameters.
6 cl, 8 dwg
FIELD: textile, paper.
SUBSTANCE: when boiling collagen, linear dimensions of leather tissue are measured before and after collagen boiling. The structure-to-structure distance is determined using difference of the sample thickness after boiling and the rated thickness of the sample before boiling, which is produced as a product of the sample thickness before boiling and a coefficient of layers number defined as a quotient from division of a lengthy sample length into the length of the sample after boiling. Invention makes it possible to realise the specified method objective.
EFFECT: method improvement.
4 ex, 3 tbl
SUBSTANCE: sorption of pharmacy drug derinate, representing sodium deoxyribonucleate in micropanel holes is carried out. After that analysed sample, which contains component C1q with unknown activity, is introduced into holes. Incubation is carried out and after washing and drying of panel into holes introduced are conjugate of enzyme with antibodies against component C1q and substrate of said enzyme. Activity of component C1q is calculated by amount of formed product of enzymatic reaction. Set contains flat-bottom micropanel with sorbed derinate, conjugate of enzyme with antibodies to human complement component C1q, substrate buffer and standard with known C1q activity.
EFFECT: method application makes it possible to increase reliability of determination C1q component with application as activator of available and stable preparation derinate.
2 cl, 1 dwg, 2 ex
SUBSTANCE: method involves filling the surface of soot with a polymer and determining the polymer adsorption value of the soot, where the polymer used is rubber. Soot dispersion is mixed with a rubber solution. Sieve diametres of the soot aggregates are determined. The specific surface of the soot is determined and relative wear resistance of the rubber is calculated from the given relationship.
EFFECT: faster and high information content of analysis.
2 cl, 5 tbl, 1 dwg
FIELD: fur industry, in particular, method for evaluating pickling quality of leather web in tanning of fur and sheepskin raw material.
SUBSTANCE: method involves providing testing on parallel groups of fur sheepskin after pickling on three topographic portions of sheep skin surface: skirt, spine and neck portions; processing samples of each group with acid-salt solution for 24 hours; withdrawing sheepskins of each group from acid-salt solution in predetermined time intervals; removing excessive liquid; placing said samples into tensile testing machine and stretching lengthwise of spine line by 40% relative to initial length thereof; holding samples in stretched state for 1 min and withdrawing from tensile-testing machine; leaving samples in free state for 10 min; determining residual elongation value in mm.
EFFECT: reduced time for determining quantitative pickling characteristic of skin web.
2 tbl, 2 ex
FIELD: fur industry, in particular, method for evaluating pickling quality of leather web in tanning of fur and sheepskin raw material.
SUBSTANCE: method involves determining quantitative pickling characteristic of leather web of semi-finished product by using time of solving thereof in alkaline solutions, said time depending on number and kind of intermolecular bindings destructed during pickling. Solving of collagen in alkaline solutions depends upon nature of preliminary acidic preparing procedure. Solving is provided in aqueous solution of potassium hydroxide having concentration of 150 g/l and temperature of 18-20 C. Derma solving time is found after preliminary thermal processing at temperature of 60-65 C during 1.5 hours. Method may be employed both in production of fur and sheepskin products and in fur processing.
EFFECT: wider operational capabilities and reduced time for determining quantitative pickling characteristic of skin web.
1 tbl, 1 ex
FIELD: methods and devices for determination of an alcohol concentration in solutions.
SUBSTANCE: the invention presents a method of determination of an alcohol concentration in solutions (versions) and a device for its realization (versions). The first version of the method provides for placement of a bath with the reference and investigated solutions on the path of the optical beam, measuring and introduction into the memory of the computation unit of intensity of the light absorption by the reference solutions, measuring of the intensity of the light absorption of radiation of the investigated solution, processing the data of the measurements of the light absorption. The investigated solution is transilluminated within the range of the wavelengths of 1250-1350 nanometers. Simultaneously with the measurement of the light absorption by the investigated solution measure the concentration of alcohol in it. In compliance with the received values determine a concentration of alcohol in the investigated solution. The second version of the method provides for placement of a bath with the reference solutions and investigated solutions on the path of the optical beam, measurement and introduction into the memory of the calculation device of intensity of the light absorption of radiation by the investigated solution, processing of the received values of the measurements of the light absorption. The investigated solution is transilluminated within the range of the wavelengths of 1250-1350 nanometers, measure the values of density of the reference solutions and the investigated solution, using which determine the concentrations of alcohol and sugar in the investigated solution. The device for the first version contains a computation unit, a conjunction unit, optically coupled a radiating unit, a bath for solution, a measuring photoreceiving device, the output of which is connected through the conjugation unit with the computation unit and the input of which is optically connected through the bath with the radiating unit. The device for measurement of a concentration of sugar in a solution consists of a beam splitter plate and an additional photoreceiving device, the output of which is connected through the conjugation unit with the computation unit. The input of which is optically connected through the beam splitter plate mounted at Brewster's angle to a axis of radiation and the bath with by a radiation unit. And the radiation unit has the wavelength of radiation laying within the range of 1250-1350 nanometers. The device for determination of a concentration of alcohol in the solutions consists of the computation unit, the conjugation unit, the optically connected radiation unit, the bath for solution, the measuring photoreceiving device, output of which is connected through the conjugation unit with the computation unit, the density gage connected with the bath by means of the pipe duct. The output of the density gage is connected through the conjugation unit with the computation unit. The radiation unit has the wavelength of radiation laying within the range from 1250 to 1350 nanometers. The invention allows to improve accuracy of measurements.
EFFECT: the invention ensures an improved accuracy of measurements.
12 cl, 5 dwg
FIELD: agriculture, in particular, dairy farming.
SUBSTANCE: method involves determining tightening of teat cup liner before it is inserted into teat cup; acting upon teat cup liner by suspending weight for determining tightening of teat cup liner; providing expansion by introducing internal gauge into teat cup liner which is positioned within teat cup casing. Method allows extent of teat cup liner tightening to be visually detected at any time of machine milking process. Tightening of teat cup liner manufactured integral with milk pipe as well as separately therefrom is determined during operation of milking units.
EFFECT: increased efficiency and reduced milking time.
FIELD: technologies for researching durability properties of packing washer materials for collapsible oil pipelines.
SUBSTANCE: in the method for determining remaining resource of rubber compacting curves utilized in oil pipeline junctions, preparation of samples of given geometrical shape is performed, measurement of source hardness conditions for stretching, relative elongation during tearing, Shore hardness, temperature fragility limit, comparison of aforementioned values to given values, culling of washers, sample coefficients of which do not correspond to given values. Remaining samples are exposed to oil product after extraction from oil product samples are thermostatted, cooled down to normal room temperature, and then the same physical-mechanical coefficients are measured again with limit values. Before preparation of samples with given geometrical shape, washers are organized in batches of same manufacturing plant and production year, additionally measured are external d1 and internal d2 washer diameters for each batch, relative compression Ecp deformation of same washers. Their deviation from standard is calculated and culling of aforementioned washer batches is performed on basis of allowed values Δd1, Δd2 and Ecp, while as allowed values Δd1, Δd2 ≤ 3%; 25% ≤ Ecp ≤ 70%. After that remaining rings with least values of relative compression deformation Ecp are utilized to prepare geometrical samples of given geometrical shape. Remaining resource ΔT is determined from following formula: years, where ki - coefficient, characterizing alteration of remaining resource ΔT dependently on climatic zone input of operation of rubber packing washers, is taken as i - climatic zones I1 - II12, additional information, T - average lifetime of rubber packing washers until removal from operation in accordance to technological characteristics provided by manufacturing plant and/or operation instructions, in years, Tn - period of operation of rubber packing washers since production year - marking of manufacturing plant, until moment of determining ΔT, years, fpδ=9,4 MPa - minimally allowed value of conditional hardness for stretching after thermostatting of sample, MPa.
EFFECT: reliable trustworthiness of results of estimation of remaining resource under dynamic conditions of rubber packing washers in oil pipeline junctions with simultaneous increase of ecological safety due to decreased risk of emergency spilling of oil products.
FIELD: investigating or analyzing materials.
SUBSTANCE: method comprises preparing specimens of polymeric materials of specified mass, exposing the specimens to the hostile fluid at a given temperature, and determining informative characteristic from a formula proposed.
EFFECT: enhanced reliability.
2 dwg, 7 tbl, 2 ex
FIELD: weighing equipment; chemical mechanical engineering.
SUBSTANCE: method can be used for measuring content of binder in reel-up composite material produced by preliminary soaked thread. Method is based upon weighing. The constant values are determined according to the method as length of thread for specific type of items and value of linear density averaged for any reel before and after soaking by binder and reeling it up onto frame. Weighing is performed for item before reeling it up with soaked thread and after reeling-up and final polymerization of composite material to determine mass of composite. Basing upon the data received, content of thread is determined which value is subsequently used for finding mass content of binder in composite from relation of C=(M-LxT/M)x100%, where C is content of binder in composite, in mass percent; M is mass of composite, g; L is length of thread consumed for item, km; T is average arithmetic meaning of values of linear density of thread and its rests at any reel before and after impregnation, g/km.
EFFECT: higher stability of performance measures.
FIELD: light industry.
SUBSTANCE: method comprises recording response of the material to be tested that represents an amplitude-frequency characteristic, calculating deformation characteristics, and determining the value of distributed mass of the vibrating part of the material. The response representing two amplitude-frequency characteristics is recorded for the same part of the material to be tested for various masses of two bodies that cause deformation. The deformation characteristics are calculated from equations of vibration theory for viscoelastic bodies.
EFFECT: enhanced precision and reliability.
FIELD: investigating or analyzing of materials.
SUBSTANCE: method comprises investigating threshold capabilities of the multi-layer polymeric material and determining maximum permeability of oil product and time period required for reaching the maximum permeability.
EFFECT: enhanced reliability.
1 dwg, 1 tbl
FIELD: investigating or analyzing of materials.
SUBSTANCE: method comprises preliminary conditioning of rubber specimens in paraffin hydrocarbon with 12-16 atoms of carbon in the atmosphere of neutral gas and in the fuel to be tested at a temperature of 130-150°C for 3-5 hours.
EFFECT: enhanced reliability.
1 dwg, 2 tbl, 1 ex