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The effect of stretching rate on the deformation behavior of polyethylene fibres prepared by the gel-technology method and which have different stretch ratios has been investigated.

The physicomechanical characteristics of gel-fibers from SHMPE which have been drawn to various stretch ratios have been studied.

A method for calculated prediction of the stretching diagrams of Nitron yarn within the range of two decimal orders of magnitude in rate of deformation within a total deformation range of 1–6% has been set forth.

A method is proposed for predicting the restoration deformation process by the use of viscoelastic characteristics determined in view of the residual component of deformation, and also of the structural parameter determined by short-term measurements of the RDP. It is recommended to carry out a calculative prediction of restorative deformation processes with allowance for the residual component of deformation, and also with allowance for the increase in “blurred-outness” in distribution of the retardation time.

A procedure has been developed for determining elastic-relaxation characteristics from short-term relaxation measurements.

A method of determining the deformation characteristics of polycaproamide complex yarns over a wide range of extension (4–8%) by short-term measurement of the parameters of the relaxation process has been developed. A modernization of the determining nonlinear viscoelasticity equation has been carried out, and a procedure based on it has been developed for the calculated prediction of stretching diagrams over a wide range of extension at an assigned rate. It is also recommended to use the procedure developed for the mathematical description of more complex deformation regimes.

The dependence of the large period on the macrostrain of a commercial polyfilament of PA-6 proved to be stepped. The steep portions of this dependence are associated with uncoiling of the through segments in the intrafibrillar amorphous layer to a trans -conformation and the sloping with the stretching of the trans -isomers. Such an interpretation is confirmed by the dependence of the mean length of the coherently scattering portion on the macrostrain which has marked maxima for the same strains when growth of the large period slows. The presence of several of inhibited growth of the large period is linked with the non-simultaneity of straightening of various through segments apparently caused by shifts of the planes of the hydrogen bonds in the crystallites.

Empirical relationships have been obtained which describe satisfactorily the effect of basic spinning parameters on nonuniformity in the diameter of the undrawn yarns; these make it possible to calculate optimum parameters which ensure an assigned level of yarn nonuniformity in diameter.

Dependences have been obtained which make it possible, for the stretching scheme examined, to carry out a comparison with a monofilament which is uniform in diameter, with respect to limiting stretch ratio and strength after stretching, at any character of change in diameter of an undrawn filament.

An analysis has been made of the mechanical properties of high-modulus polyethylene monofilaments prepared by gel-technology.

The lifetime of rubber-tire cord specimens and the character of their failure depend on the density of the cord filaments in the specimens.

A method has been developed for determining the deformation characteristics of polycaproamide yarns, which differs from the previously known ones by allowing for relaxation contributions in loading the specimen.

height had been left out of account. The height at which the t roughs a r e s i tuated prevented opera t ives of shor t s t a tu re to c o r r e c t the fault. A large number of inf r ingements like "misa l igned auger s" or "miss ing or b roken y a r n guide hooks" were caused main ly by a lack of at tention on the par t of the tending personnel who cons idered these faults to be "of no s igni f icance".

On the basis of measurements of relaxation and high-speed stretching which disclose the effect of the rate of mechanical action on deformation properties, a method has been developed for the quantitative description of high-speed stretching diagrams which reflect the use conditions of a number of articles for technical purposes that are made from Kapron yarn.

The important service properties of cord yarn are tenacity and deformation behaviour and the stability of these properties to changes in the external load and in the temperature of the ambient medium. The writers investigated the deformability of stabilized polyamide cord yarn in comparison with tha% of unstabilized standard polyamide yarn. The results were compared with corresponding data for polyester yarn.