Prediction of creep behavior of laminated woven fabric with adhesive interlining under low stress in the bias direction

The effect of adhesive interlining on the creep behavior of a woven fabric in the bias direction was investigated. Three-element viscoelastic models were used to approximate the creep behavior of a face fabric and adhesive interlining. The creep model of a laminated fabric comprised a six-element model in which two three-element models are connected in parallel with the three-element model. Creep tests were carried out using face fabrics, adhesive interlinings, and their laminated fabrics without and with bonding adhesive interlining by hanging samples in the 45 degrees bias direction under their own weight for 7 days. Creep strains of face fabrics bonded with adhesive interlining were found to be weaker than those of the face fabrics. The creep behavior for the face and interlining fabrics could be approximated using the three-element viscoelastic model with appropriate parameters. The experimental creep behavior of a laminated fabric without bonding was similar to the theoretical behavior. However, the experimental creep of laminated fabrics with bonding interlining was less than the calculated creep, owing to the increase in stiffness due to the adhesive. By revising the six-element model with the strains just after hanging and for 2 days, it was possible to predict the creep strain over 7 days

Wpływ struktury materiałów wierzchnich i wkładek obuwniczych na ich właściwości elektryczne

Protective footwear for occupational use conducts static electricity through the upper, linings, insole and outsole into the ground. Footwear must be made from appropriate material to reduce the possibility of electrocution and other electricity-related incidents.In this study the influence of footwear materials for the upper and lining components’ structure on their electrical properties was investigated. For investigations leather and various textile laminates were chosen. The thickness of leather coating, composition textile laminates, the upper–lining system, and relative humidity of the environment on electrical resistivity changes were evaluated. Leather shows antistatic properties at standard humidity, but its electrical conductivity greatly increases at high humidity due to the presence of polar groups in the leather structure. Textile lining laminates composed of natural and synthetic fibres are insulators, but their systems with leather at high humidity show resistivity values close to antistatic materials. Leather acrylic coating decreases the electrical conductivity of materials.Obuwie ochronne do użytku zawodowego przenosi ładunki elektrostatyczne przez materiał wierzchni, wkładkę i podeszwę w ziemię. Obuwie musi być wykonane z odpowiedniego materiału, tak aby zmniejszyć ryzyko porażenia prądem i innych incydentów związanych z energią elektryczną. W pracy zbadano wpływ struktury materiałów obuwniczych na ich właściwości elektryczne. Do badań wybrano skórę i różne laminaty tekstylne. Oceniano wpływ grubości powłoki skórzanej, rodzaj kompozycji laminatów tekstylnych oraz wilgotności względnej otoczenia na zmiany rezystywności elektrycznej. Skóra wykazuje właściwości antystatyczne przy standardowej wilgotności, ale jej przewodność elektryczna znacznie wzrasta przy wysokiej wilgotności ze względu na obecność grup polarnych w strukturze skóry. Laminaty z włókien tekstylnych składające się z włókien naturalnych i syntetycznych są izolatorami, ale po połączeniu ich ze skórą w wysokiej wilgotności wykazują wartości oporności zbliżone do materiałów antystatycznych. Stwierdzono także, że skóra z powłoką akrylową charakteryzuje się zmniejszoną przewodnością elektryczną materiałów

Alliance persistence, military security, and the 2016 Brexit referendum : the case of Estonia and the United Kingdom

Published online: 21 March 2019Driedger assesses the development of military and security ties between Estonia and the United Kingdom between 2014 and 2018. Focusing on the 2016 Brexit referendum, he shows that, in contrast to previous assessments, these ties strengthened after the referendum. Driedger argues that this development is largely shaped by perceptions of increasing mutual alignment utility. He develops a new theoretical framework of security alignment strength and uses structured and focused comparison on a wide array of British, Estonian, and Russian sources, including interviews with defence officials and an analysis of key policy documents. As the case of Estonia resembles others in the region, this study yields crucial insights for assessing North-East European security, developing alliance theory and informing policy-making towards Russia in a time of populist crises