Fibre Chemistry最新文献

Issues of methodology and adequacy of mathematical modeling of polymer textile materials relaxation processes are examined. The developed integral criteria of confident prediction of polymer textile materials relaxation processes are based on minimization of integral functional convolution corresponding to a specific equation of state. The developed criteria of confident prediction of polymer textile materials relaxation processes can be introduced by their computerization.

The problem of detecting inhomogeneities of extended products along their length is considered. Such products are examined using nondestructive testing scanners. The as-obtained data is represented as a time series. The paper proposes an algorithm for detecting defects by analyzing this time series. The method of computer modeling allows the process of fiber and yarn inspection to be simulated.

A method for evaluating the functionality of polymer textile materials with the purpose of increasing their competitiveness is presented. The functionality of polymer textile materials is assessed based on mathematical modeling of their viscoelasticity. To that end, a widely-recognized approach to mathematical modeling of viscoelasticity of polymer materials is considered. This approach involves an analytical approximation of experimental families of relaxation and deformation curves by normalized relaxation and deformation functions on a logarithmic scale of reduced time.

The compressibility of composite materials prepared by impregnation with an aqueous polyurethane dispersion of cloth made of polypropylene fibers of linear density 0.66 tex was studied. An approach to the determination of the dependence of the compressibility of the composite materials on the degree of impregnation of the cloth and the pressure on the materials was proposed. The optimal degree of impregnation of the cloth above which a substantial drop of the compressibility was observed was established. The compressibility decreased if bridges of polyurethane particles formed between the fibers. The orientation of the cloth fibers, which depended on the linear density of the fibers during punching of the fabric, was another structural factor determining the compressibility of the composite materials.

A composite material based on sawdust and a binder, which was a multicomponent synthetic polymer and thermosetting plastic, in particular, a modified epoxy resin with a hardener, was studied. The ability to use the composite material for layered preparation of items was confirmed by results of thermomechanical studies. The temperatures at which the composite material with a sawdust content up to 30% transitioned from a glassy state to a highly elastic state were determined. The temperature intervals characteristic of a plateau of the highly elastic state and the transition temperature of the multicomponent composite polymer into a viscous-flow state were determined. The results allowed the optimal content of sawdust in the composite material to be established (20-25%), which corresponded to a stronger state of the material. The results agreed with the tendency to increase the mechanical properties and change thermomechanical curves of wood-based composites shown by scientists from various countries. The novelty consisted of the established limits for the sawdust concentration in the thermosetting plastic, which was a multicomponent composite based on epoxy resin with a hardener. The practical significance of the work was associated with the production of the required temperature and time modes for 3D-printer operating on additive technology for deposition of a polymer in a liquid aggregate state.

The influence of duration of continuous needlepunch loom operation for additional punching on conventional stress and relative tensile elongation of fabrics was studied. Duration of operation considerably affects the conventional breaking stress and has practically no effect on relative breaking elongation. During the first fabric passage through the needlepunch loom, the conventional stress in the longitudinal and vertical directions of the fabric in 2 days of continuous operation of the loom diminishes by 10−15 % and totally in 8 days, by 20−30 %. Conventional breaking stress correlates with /bulk density of the fabric. An equation is proposed for predicting the ratio between the change of the conventional stress and the bulk density of the fabric in the process of additional punching as a function of duration of continuous operation of the loom.

The optical and mechanical properties of secondary fibers of a new type of Russian office paper SvetoCopy Eco were studied after purification by various methods. The studied optical properties were whiteness, brightness, fluorescence, and opacity. Data for entrapment of toner in the samples were also given. The region of toner entrapment was distributed evenly during preliminary two-stage dry dispersion of the fibrous material, which led to a reduction in the whiteness and total removal of toner visible to the naked eye. It was experimentally established that the enzyme α-amylase increased the optical properties of the samples whereas their mechanical properties decreased insignificantly. Domestically manufactured enzymes were used for the first time during flotation of SvetoCopy Eco paper, which increased the practical significance of the results. The effect of two-stage dry dispersion, which practically completely removed entrapped toner, was studied. However, this reduced the whiteness and mechanical properties of the fibrous material. A complex of chemical reagents was used in experimental studies on toner removal.

The article is devoted to thermoanalytical studies of upholstery fabrics and nonwoven materials of cushioned furniture for assessment of their fire risk. The results of determination of inflammability parameters of textile materials with reduced fire risk are presented.

The effect of triethylbenzylammonium chloride, trimethylcetylammonium bromide, trimethyllaurylammonium bromide, and N-cetylpyridinium chloride on the dyeability of polypropylene fiber by disperse dyes from aqueous solutions by a periodic method was studied. The change of tensile strength of polypropylene thread resulting from heat treatment by aqueous solutions of quaternary ammonium salts was evaluated. The studies allowed trimethylcetylammonium bromide to be recommended as an enhancer of disperse dyeing of polypropylene fibrous materials.

Industrial facilities, including those specializing in chemical fiber production, are a major source of carbon dioxide, sulfur and nitrogen oxides, and particulate matter emissions. These emissions degrade air quality, affect climate change, and have adverse effects on ecosystems and human health. This paper presents a mathematical model for calculating a scrubber for purifying and heat recovery of the moist air emitted by various devices of chemical fiber production enterprises.