**4. Influence of the non-woven textiles on the indoor environmental quality**

### **4.1. Non-woven textiles as floor coverings**

Semi-Volatile Organic Compounds (SVOCs) are associated with the presence of phthalates, pesticides, and flame retardants, which can be frequently found on textile surfaces in the indoor environment [11]. Microbial volatile organic compounds (MVOCs) are formed in the metab‐ olism of fungi and bacteria [12]; therefore, they can be found in the indoor environment due

A recent work [13] has summarized the state of the art in the field of the Very Volatile Organic Compounds (VVOCs) – an important subgroup of indoor pollutants that involves a wide spectrum of chemical substances. However, there is still no clear definition of VVOCs and

Needle-punched non-woven textiles can be found as backing of carpets and wall coverings, and also as low-quality blankets, hidden layers in furniture systems, and wadding/padding. Spunlaced/hydroentangled non-woven materials are used in furnishing and bedding, as coverings and sheets. Spunbonded non-wovens are applied as a backing layer for wallcover‐ ings, carpets, curtains, and furniture. They are also used as upholstery layers, filters, and tablecloths. Tablecloths are also made of wet-laid and spunlaced non-wovens. Chemically bonded non-woven textiles are applied as wadding and padding. The same is the application of the thermally bonded non-wovens, which are also applied in carpets underlying and furniture systems, including as upholstery textiles. The tufting technology is used for produc‐

Table 1 summarizes the main applications of different types of non-wovens in the indoor

Several specific requirements have to be taken into account when designing non-wovens for application in the indoor environment. These requirements are related with both the product in question and its particular function: strength, dimensional stability, volume density, wear resistance, air-permeability, etc. There are other design considerations, however, related to the

Non-wovens influence all basic metrics of IEQ. They may be used for sound control in residential and public buildings, or for glare reduction. As many textiles in public places, nonwovens are required to be flame-resistant. This additional treatment may be in a conflict with the demands for indoor air quality. The maintenance of the textiles surfaces is related to their ability to accumulate dust; therefore, the cleaning of the visible non-woven textiles in the indoor environment has to be easy. The last is also related with the products, as the cleaning

Non-wovens have very good insulation abilities, used as floor coverings, wallcoverings, upholstery textiles (hidden layers or outer, visible layer), bedding, and they influence the indoor thermal quality. At the same time they can be a source of unpleasant odors, decreasing the indoor odor quality, especially in the case of floor coverings, including carpet backing. The

to presence of moisture and mold growth.

**3. Non-woven textiles in the indoor environment**

tion of carpets for both built environment and car interiors.

basic metrics of IEQ, which should be taken into account.

agents themselves could frequently be sources of airborne pollutants.

techniques for their assessment.

192 Non-woven Fabrics

environment.

Non-woven textiles, used as floor coverings in the indoor environment, increase the aesthetic comfort of the inhabitants. At the same time they influence thermal, acoustic, visual and odor environment, as well as indoor air quality.

Textile floor coverings have several advantages over other types of flooring (tiles, cement, wood, linoleum, bamboo, etc.) [9]. They increase the quality of the thermal environment; their insulation varies between 0.1 m2 K/W and 0.3 m2 K/W [14]. The insulation abilities are even better if a combination between hard flooring and textile floor covering is used.

Non-woven carpets influence the quality of the acoustic environment as they reduce noise levels indoors. They absorb the sound of steps and dropped objects and the absorption is higher when a pile carpet (tufted carpet) is used. At the same time, the quality of desired sound (music, speech) remains constant.

From economical point of view, the use of textile floor covering indoors can decrease or even eliminate the costs for sound and thermal insulating materials, especially in residential buildings.

Textile floor coverings do not reflect light; therefore, they can be used for glare reduction in the indoor environment, especially when hard flooring is also applied. The contact between sunlight and the textile fibers (mainly wool) leads to photobleaching effect, which requires additional treatment. However, all treatments of carpets, including those for stain blocking, fire resistance, moths blocking, etc., may affect negatively the indoor air quality (IAQ).

Several authors report and analyze the connection between IAQ and wall-to-wall non-woven carpets. Tufted carpets release Volatile Organic Compounds (VOCs) weeks after their install‐ ment in the indoor environment, due to the adhesives used for their fixation [15]. The cleaning of the near-wall zones is also very important, as they are a big source of airborne pollutants due to difficulty of access [16].

The surface pile of tufted carpets is indicated as a very important source of airborne pollutants in the indoor environment [15, 17-19]. The pile accumulates dust and particles, thus converting the tufted carpet into a "reservoir" for pollutants [9]. In addition, wool fibers can absorb formaldehyde, oxides of nitrogen and other toxic pollutants from the air [14]. Regular vacuum cleaning and wet extraction with cleaning products is a way of reducing the VOCs absorbed in the floor covering, but the cleaning products themselves are also a source of VOCs [9].

Tufted and needle-punched floor coverings can also be a source of VOCs and SVOCs in the indoor environment because of the backing. Tufted carpets need more complex finishing than woven carpets to obtain dimensional stability [20]. Synthetic latex is applied for backing of both needled and tufted floor coverings, which can be associated with airborne pollutants and unpleasant odors.

At the same time, Whitefoot [14] has reported the absence of scientific evidence that the removal of carpet alone has a proven effect on the health of the inhabitants. The author has discussed the advantage of pile carpets, including non-woven carpets, the surface of which can trap airborne pollutants and allergens, thus decreasing health problems related to allergy and asthma.

The study by Kidesø et al. [21] has concluded that heavy-weight needle-punched and tufted carpets from polypropylene and polyamide are particularly appropriate for residential buildings. The authors especially have underlined the requirement for smooth surface or surface with very low pile. The use of floor coverings with synthetic fibers, however, increases the risk of Microbial Volatile Organic Compounds (MVOCs) in the air. The higher humidity of the indoor air may provoke the development of mold and mildew; as a result, the carpet becomes a source of microbial airborne pollutants. Regular cleaning and use of antimicrobial additives is a solution against MVOCs, especially in indoor environments with high traffic and high humidity [22]. At the same time, antimicrobial treatment (applied on the carpet fibers, the carpet backing, etc.) must exclude volatile organic chemicals (VOCs and SVOCs), toxins, allergens, carcinogens, and other substances that are dangerous for humans and animals [23].
