**5. Well-being and comfort**

Physiological comfort determined by skin parameters, such as temperature and moisture, is affected by raw materials as well as clothing design and depends particularly on the suitability of worn type of clothing to the level of physical activity of user and ambient climatic conditions.

Hemp and flax fibers show high ability to moisture sorption from ambient air. The hygroscopicity of lignocellulosic fibers depends on the relative humidity of air, which is shown in **Table 4**. The fibers can absorb more moisture in conditions of higher relative humidity of air, which means, in practice, that the linen/hemp clothing easily absorbs sweat produced by the human body. In the case of conditions of everyday life and moderate physical effort, the clothing ensures optimal comfort to the wearer, allowing easy skin breathing and air exchange from the


#### **Table 4.**

*Effect of relative air humidity on the hygroscopicity of selected bast fibers [17].*

area of skin clothing to outside. In the case of high physical effort, doing sports, when the intensity of sweating is high, the T-shirt made of cellulosic raw material becomes uncomfortable due to feeling of wet touch. Linen/hemp clothing should be dedicated to everyday life, indoor and outdoor work, leisure, tourism, and other activities with low and moderate effort, when the garment ensures optimal comfort to the human body [37].

The comparative study on comfort parameters of linen and linen/polyethersulfone (PES) clothing during moderate physical exercise was described by Zimniewska [38]. Tested shirts and trousers were prepared from linen and polyester fiber in different composition of the raw materials; share of linen in the blend with PES increased by 25% in each following clothing sample. The fabrics were characterized by the similar density of threads; linen and PES yarns produced to this experiment have similar linear density.

Values of the parameters that affected the comfort of clothing are presented in **Figures 9**–**12**.

The fabric hygroscopicity increased with increasing of the share of linen in the blends linen/PES; similarly, the time needed to drop water sorption is longer in the case of bigger PES content in the blend. The linen fabric showed the biggest value of air permeability; the lowest one was observed for 100% PES fabric. The evaluation of moisture of back skin of clothing users during 5 hours of experiment was conducted in order to assess the comfort. During the experiment, volunteers did not perform any physical activity. Results of the experiment are presented in **Figure 13**.

The results proved that the skin moisture was the lowest in case of wearing the clothing made of 100% linen; however, the biggest increasing of moisture was observed when PES clothing was worn.

Bast fiber does not gather electrostatic charges on their surface, which results in their high ability of moisture sorption. The values of electrostatic potential of the tested linen/PES fabrics are presented in **Figure 14**, where the highest value observed for PES fabric decreased when linen share in the blends increased. The presence of electrostatic charges on the synthetic clothing surface results in some kind of skin and mental irritation of garment users.
