Toplotni komfor tekstilnih materijala u dinamičkim uslovima

Abstract

U ovom istraživanju analizirani su parametri toplotnog komfora koji opisuju dinamički odziv glatkih desno-levih (DL) pletenina kao odgovor na fiziološke impulse i klimatske promene okruženja. Toplotno ponašanje ovih pletenina u dinamičkim uslovima ocenjeno je parametrima toplotna apsorptivnost i toplotna difuzivnost. Ispitivani su i sposobnost upravljanja tečnošću i sposobnost propuštanja vazduha pri različitom sadržaju vlage u pleteninama. S obzirom da su ove vrste pletenina vrlo podložne dimenzionim promenama, odnosno promenama u strukturi i geometriji, kako usled skupljanja prilikom pranja, tako i zbog ponovnog rastezanja tokom nošenja, ispitivani parametri su analizirani posle višecikličnog pranja i nošenja. Eksperimentalni materijal je obuhvatao pleteninu od konoplje, poliakrilonitrilnu (PAN) i konoplja/PAN pleteninu. Promena sirovinskog sastava pletenina, odnosno kombinovanje različitih sirovina izvršeno je u fazi izrade pletenina uz dubliranje homogenih pređa (konoplja i PAN). Konoplja je izabrana kao alternativa pamuku, zbog svojih pozitivnih aspekata održivosti, i zbog vrlo dobre predispozicije za proizvodnju komfornih proizvoda visoke vrednosti. PAN pređa je izabrana zbog poroznosti i mekoće akrilnih vlakana, kao i zbog male sklonosti ka skupljanju, i dobroj sposobnosti zadržavanja oblika. Rezultati su pokazali da je toplotni komfor glatkih DL pletenina u dinamičkim uslovima uslovljen afinitetom vlakana ka upijanju vode i njihovim toplotnim kapacitetom, ali i geometrijskom konfiguracijom kompleksne mreže pora u pleteninama. Odabrana vlakna su uticala u većoj ili manjoj meri na promene u konstrukciji i geometriji pletenina tokom višecikličnog pranja i nošenja, što je pozitivno uticalo, ili barem nije imalo negativnih efekata na ispitivana svojstva glatkih DL pletenina posle perioda nege i nošenja.

In this investigation the thermal comfort parameters that describe the transient response of plain jersey knitted fabrics due to the changes in physiological and environmental conditions were analyzed. The transient thermal response of the knitted fabrics was defined by thermal absorptivity and thermal diffusivity. To determine moisture and air management properties of the knitted fabrics during the transient period, both liquid and air permeability as a function of moisture content were determined. Given that this type of knitted fabrics are very prone to structural changes not only due to laundering but also as a consequence of the mechanical stresses during wearing, the effects of repeated wear and care cycles of the knitted fabrics on their transient thermal comfort response were analysed. The experimental material included the pure hemp, pure acrylic (PAN) and hemp/PAN knitted fabrics. The composition of the blended knitted fabric was designed at the knitting production stage. The hemp was chosen as a more sustainable alternative to cotton with very good predispositions for production of comfortable, high-added value products. Acrylic yarn was chosen to be combined with the hemp component primarily because acrylic fibres are porous and soft, with low shrinkage and good shape retention ability. The transient thermal comfort response of the knitted fabrics was affected by the fibre regain and thermal capacity, but geometric configuration of the complex porous network in knitted fabrics also influenced the tested properties. The results indicated that chosen fibres affected some changes in the constructional and geometrical parameters of the knitted fabrics after undergoing usage cycles, which positively affected, or at least had no negative effects on the investigated properties after the trial period.