Fibrillation of Lyocell fibres due to different treatment conditions

Razlike procesov pridobivanja različnih regeneriranih celuloznih vlaken povzročajo različno morfološko zgradbo vlaken, ki se kaže tudi v različnem nagnjenju k fibriliranju. Zaradi visoke orientacije in kristalinosti vlaken kažejo liocel vlakna močno težnjo k fibriliranju, t.j. cepljenju fibrilov vzdolž vlaken. Nabrekanje in mehanske obremenitve ta pojav pospešijo in ojačajo. Zelo tanki fibrili na površini vlaken in njihovo kodranje povzročijo povečano površino vlaken in s tem spremembo površine tkanin. Metoda, ki so trenutno na razpolago za ocenitev stopnje fibriliranja so še nepopolne. Spremembo površine vlakna kot funkcijo fibriliranja lahko zaznamo optično ali po spremembah otipa. V prispevku smo predstavili novo metodo zasledovanja fibriliranja s spremembo optičnih lastnosti tkanin, in sicer Tencel vlaken. Z obdelavo in kvantitativno analizo mikroskopskih slik smo določali spremembe oblike in velikosti por v tkanini, ki so nastale kot posledica različnih postopkov obdelane, n. pr. fibriliranje surove tkanine, encimatska obdelava in zamreženje liocel vlaken.The differences in the man-made cellulose fibre forming processes produce some varieties in the morphological structure of fibres, which shows in fibres\u27 different tendency to fibrillate, i.e. to split along the fibre axis. The basic parameters connected with the high degree of crystallinity and orientation of lyocell fibres are also the reason for lyocell fibres\u27 high tendency to fibrillate. Fibre swelling and mechanical stress promote this effect. Very fine fibrils on the fibre surface and their crimping increase the fibre surface and thereby influence the surface changes of the fabric. Some methods for following the formation of fibrils, their density and homogeneity have been proposed, but have proved to be insufficient. The changes of the fibre surface due to fibrillation can be followed optically or by handle changes. In the paper a new method for observing the changes of optical properties of lyocell fibres influenced by fibre fibrillation is given. The analyses were performed on Tencel fabrics. Processing and quantitative analysis of microscopic images was involved for studying the form and dimensions of fabric pores that were produced by different treatments, like raw fabric fibrillation, enzyme treatment and crosslinking of lyocell fibres