Tatjana Rijavec

Physical and chemical effects of washing and wet cleaning on durable press finished cotton fabrics

The influence of wet cleaning, as a promising process compared to washing, on the physical and chemical properties of functional cotton fabrics with high added value is presented. Fabric characterization before and after durable press finishing and after 10 cycles of washing and wet cleaning is made using standard methods – measuring dimensional stability, construction characteristics, crease resistance, tensile properties, swelling properties, appearance with coefficient of friction and geometrical roughness, surface characterization by scanning electron microscopy and electrokinetic potential. It can be seen that wet cleaning, which has been used in practice, together with adequate pretreatment, as a substitute for dry cleaning, can also be successfully implemented as a process to substitute washing, particularly when high-value-added articles are concerned.

Dynamic Mechanical Properties, Superstructure, and Texturability of PA 6.6 Partially Oriented Yarns

The results of dynamic mechanical testing of five industrially produced partially oriented yams (POY) and two conventionally spun and drawn PA 6.6 filament yams are presented, along with some of their structural parameters. Dynamic mechanical spectra of POY samples differ from conventionally spun and drawn yams across the entire testing temperature range from 20 to 260°C according to their superstructure parameters. Differences in the low temperature range are primarily due to amorphous orientation, whereas differences in the high temperature range are ascribed to the perfection and stability of the crystalline structure. Preoriented yams of lower orien tation and unstable crystalline structure are more suitable for the simultaneous false- twist draw texturing process than the POY with more stable crystalline structures and higher orientation.

Properties of laminated silica aerogel fibrous matting composites for footwear applications

This paper describes a lamination method of commercially produced silica aerogel composite and investigates its suitability for thermal insulation within protective footwear applications for severe cold and extreme high-altitude environments. A silica aerogel composite was used with a thickness of 2.7 mm and mass per unit area of 500 gm–2. Silica aerogel dust, which is generated during the crushing of brittle silica aerogel, was prevented from spreading into the environment by two-sided lamination of silica aerogel composite. A solid 5 µm thick membrane was used, reinforced with an abrasive resistant polyester knitted fabric. The thermal conductivity of laminated silica aerogel composite was comparable to that of the non-laminated one and amounted to 0.016 Wm–1K–1. Water vapor permeability of the laminated silica aerogel composite was 1.31 mgcm–2h–1. The silica aerogel composite was subjected to 30,000 cycles of flexing in order to study the impact of its irreversible crushed structure on the water vapor permeability and thermal resistances of laminated samples. It was observed that flexing did not damage the membrane of the laminated composite and had no statistically significant effect on its thermal resistance and water vapor permeability. During this study it was confirmed that the newly developed laminate has potential applications within protective footwear for extreme cold temperature environments.

Effect of flexing deformations on functional properties of laminated silica aerogel fibrous matting composites for footwear applications

Silica-aerogel composite, a silica-aerogel reinforced with fibrous matting, are being considered as an isolative material for footwear. The suitability for such applications has been investigated in the study presented in this article. Experiments were conducted on laminated silica aerogel composite (LAC). Lamination of silica aerogel composite with a solid membrane is needed to prevent spreading of crushed silica aerogel dust into surrounding. LAC was subjected to cyclic of flexing to simulate mechanical stress that occurs during normal usage condition in footwear applications. The study highlights the impact of the irreversible crushed structure of silica aerogel on the permeability and thermal resistance, tensile properties and the quality of lamination.

POVEZANOST MEHANIČKIH SVOJSTAVA PLETENINA I ERGONOMSKE UDOBNOSTI SPORTSKE ODJEĆE

Kvalitet sportske odjece se ocjenjuje preko njene toplotno fizioloske i ergonomske udobnosti. U ovom radu je ispitivana povezanost mehanickih svojstava pletenina i ergonomske udobnosti odjece. Sportska odjeca se izrađuje od razlicitih vrsta materijala koji vizuelno mogu izgledati isto, ali kada su u pitanju mehanicka svojstva koja su uveliko povezana sa prilijeganjem i deformacijom odjece u toku upotrebe, između njih može postojati znacajna razlika. Za izradu ženskih biciklistickih hlaca koristene su dvije vrste pletenina istih konstrukcijskih karaktristika ali razlicitih sirovinskih sastava. Od navedenih pletenina izrađena su dva modela ženskih biciklistickih hlaca. Za izradu oba modela hlaca koristeni su krojni dijelovi iste konstrukcije ali sa kombinacijama pletenina razlicite rastegljivosti za pojedine krojne dijelove radi postizanja bolje ergonomske udobnosti. Povezanost mehanickih svojstava pletenina i ergonomske udobnosti modela ženskih biciklistickih hlaca utvrđivana je kroz probe nosenja i subjektivno ocjenjivanje.