Internal structure and pigment granules in colored alpaca fibers

Abstract

Alpaca fibers have some distinct properties such as softness and warmth, which have not been fully understood in combination with the fiber internal structures. In the present investigation, the internal structures of alpaca fibers have been closely examined under the scanning electron microscope (SEM), especially in the longitudinal direction. The results showed that numerous pigment granules reside loosely inside pockets in brown and dark-brown alpaca fibers. These pigment granules were mainly distributed inside the cortical cells, the medullation regions as well as underneath the cuticles. Their size in the brown alpaca fibers was smaller and more uniformly round than in the dark-brown fibers. These granules in colored alpaca fibers loosen the bundle of cortical cells, providing many crannies in the fibers which may contribute to the superior flexibility, warmth and softness of the fibers. Moreover, there are no heavy metal elements found in the granules. The mordant hydrogen peroxide bleaching employed could eliminate the pigment granules and create many nano-volumes for further dyeing of fibers into more attractive colors.

Características productivas y textiles de la fibra de alpacas de raza huacaya

“…Algunas fibras de alpaca aparte de la cutícula y corteza, tienen una médula en la parte media que se extiende a lo largo de la fibra (Rui-wen et al, 2008), y tiene un efecto aislante, de modo que las prendas que son confeccionadas con dichas fibras mantienen calor en quienes los usan (Wang et al, 2005). Sin embargo para fines del procesamiento la presencia de la médula supone un problema importante, especialmente en el teñido porque causa una mayor refracción de la luz que hace aparecer las fibras teñidas más claras (Rodríguez, 2006) En llamas, Martínez et al (1997) encontraron tasas de medulación de 20.2, 37.7 y 39.4% para fibras no meduladas, fibras con medulas fragmentadas y fibras con médula continua, mientras que Contreras y Quispe (2010) en alpacas Huacaya de color blanco, encontraron una tasa de medulación de 66.49% y, respecto al tipo de medulación, reportan tasas de medulación de 33.51, 16.14, 20.38, 12.74 y 17.24 % para fibras sin médula, con médula poco continua, médula muy continua, médula continua larga y médula continua, respectivamente.…”

Revealing the organic dye and mordant composition of Paracas textiles by a combined analytical approach

“…XRF analysis showed that this thread contains copper, which may be responsible for the green hue. Alternatively, the yellow compounds could have faded so severely that our techniques are unable to detect them (see for instance the reactivity of avonoids as shown in [40]); or the bre itself could possess a brownish-yellow colour, which combined with blue produces the nal green (the pigmentation of South American camelids has already been described in [41]); or a speci c recipe may have been used to yield a greenish hue with indigo-producing plants (as shown in [42]). It is interesting to note that the two green threads belong to the same textile, 1935.32.173, where an embroidered green ground now shows patches of different hues that were presumably once evenly coloured (Figure 1).…”

Características del vellón de vicuñas (Vicugna vicugna mensalis) de Cala Cala y Picotani (Puno-Perú) criadas en semicautiverio

“…Elaborado con base a Warthon (2003) Biológicamente, en las vicuñas y en los camélidos sudamericanos en general, las fibras aparte de la cutícula y corteza, pueden o no poseer una médula en la parte central; la misma que puede ser continua o discontinua (Bustinza, 2001). Las fibras meduladas tienen un efecto aislante, de modo que las prendas confeccionadas mantienen calor; pero para propósitos del procesamiento textil, la presencia de médula genera problemas en el teñido (Wang et al, 2005). Por otro lado, la fibra natural y resistente, como de la vicuña, es una fibra extraordinaria y sedosa, más cálida, pica menos y carece de lanolina, lo cual la convierte en una fibra hipoalergénica y poco inflamable (Liu et al, 2004).…”