A comparative analysis of two kinds of highly stretchable orthotropic textile materials (woven and knitted) reveals their behavior with spatial biaxial (membrane and punch) deformation. The investigation is illustrated by uncommon experimental cases when perpendicularly loaded disc-shaped specimens experience a stressed state very close to uniaxial tension, i.e., one of the two stresses of biaxial tension becomes negligibly small compared to the other. The conditions for a spatial textile shell to achieve an unstable shape, i.e., to wrinkle, are also analyzed.The main parts of thin-sheet materials, e.g., textiles and polymer films, during processing and service (e.g., moulding) are affected by forces perpendicular to their surfaces. As a result, shells exposed to biaxial deforma-.tion form. Two spatial biaxial deformation test methods are well known and widely used for investigating textile and polymer materials, i.e., the membrane and the punch.Recently, the number of biaxial deformation tests in materials science and technological investigations has grown. This tendency is influenced by three factors:

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The goal of this research work was experimental investigation and evaluation of biaxial punch deformation processes of anisotropic textile materials. The investigation was aimed to solving the following problems: tofind a new criterion for textile behaviour evaluation in punch loading; to evaluate theeffect of material anisotropy for the geometry offormed shell; to determine the straindistribution in anisotropic shell. The experimental data of X‐ray diffraction analysis showed that friction at specimen/punch contact, which earlier was ignored, has a significant effect upon the parameters of the punching process.

The aim of the presented research is to apply the method of punch deformation for the simulation of textile systems behaviour in serve conditions and on the basis of it create original method and find new criteria for shape stability evaluation. The research was done with the help of three devices of punch loading originally created at Kaunas University of Technology (Lithuania), which were attached to the standard tensile testing machine. Creep tests were performed by a special device, clamping radius of which was R=56.5 mm. Creep process was controlled up to the stabilisation of shells height, i.e. after t=48 h. Tests were carried out in wet and dry states of the specimen. Two different types of textile systems (I+K and K+I) composed of two layers were investigated (where K – outer material; I – interlining).

Purpose -The purpose of this research is to perform instrumental comparison of hand parameters of knitted fabrics produced from different biodegradable fibres and to analyze peculiarities of hand parameters' extent influenced by fabric structure and chemical softening. Design/methodology/approach -The hand of five types of different biodegradable fabrics was evaluated. Experiments were performed using a method based on the principle of specimen biaxial punching deformation when a disc-shaped specimen is extracted through a round nozzle. The Influence of fabric weave (terry and plain jersey) and finishing (padding with the silicone softener "Belfasin SI") on the fabric hand was investigated. Findings -Investigations have shown that weave type and finishing significantly influenced fabric hand properties. It was also stated that even tenuous differences between fabric parameters could be obtained by one numeral value of complex hand rate Q. Practical implications -Experiments have shown that KTU -Griff -Tester is a simple, reliable instrumental device suitable to obtain quantitative information about fabric mechanical properties. Evaluation of finishing influence on a fabric hand could be precisely expressed by one parameter Q. Originality/value -In the present research quantitative evaluation of new fabrics from biodegradable fibres hand was performed. Comparison between new biodegradable and traditional cotton fabrics has shown that new biodegradable fibres which are generally used for underwear, sportswear and for medical application are characterized by soft hand, as a result a good affinity with skin.