## 2 Materials and Methods
### Fibers and Yarns Design and Manufacturing of the New Kind of Triple-Layer Thermo-Insulated Fabric  
Once the warp and weft yarns are realized, it is possible to design a new concept of triple-layer thermo-insulated fabric. The textile product, as depicted in Figure 4, consists of three layers comprising:  
* A first woven protective layer (outer layer), designed to be the outer layer of the garment. Such a layer is treated with a non-formaldehyde crosslinking agent to convey waterproof properties.  
Figure 4: Double feeding system used to produce the volumized yarn.  
Figure 3: Double feeding system used to produce the volumized yarn. Comparison between a typical yarn obtained by adopting conventional ring-spinning and the volumized one.  
* An intermediate layer, which overlays the first protective ones. In such a layer, the volumized yarn is woven with a triple weave architecture. Such a middle layer is created by a single weaving operation, allowing the volumized yarns to be weaved once with the backrest.
* A second outer layer (inner layer), which is also of woven type.  
The three layers are inseparably joined together by weaving (see Figure 5). The main innovation of the proposed fabric is to use a fabric obtained by weaving the volumized yarns along with the supporting yarn in nylon as an intermediate layer. In detail, to confer the desired volume of the layer thus granting the desired air entrapment for assuring the thermal insulation, the intermediate layer has a triple weave architecture. Furthermore, the fabric is obtained in one process on the loom, thus avoiding the need of joining together the internal and external layers in a second process phase.  
As is widely known [19], the weave of a fabric is graphically represented on checkered paper (technical paper) where the rows of vertical checkers represent the threads of the warp, and the rows of horizontal checkers represent the wefts. The full square indicates the point of intersection where the thread passes over the weft, while the empty square indicates that the thread passes under the weft.  
Starting from the yarns defined in Section 2, two main fabric compositions for T4 Innovation prototypes are set:  
* Type 1: 60% WV-40% PA
* Type 2: 67% WV-33% PA  
According to the different composition, and in order to test different possible solutions from both the technical and the aesthetic point of view, seven different prototypes were weaved, as shown in Table 3.  
For each of them, a textile CAD design of the triple weave to be used was carried out. Accordingly, each prototype is characterized by a different weave architecture and color. Figure 6 shows the architecture of the prototype labeled with code 285,989.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**T4 Innovation Prototype (Reference Code)** & **Typology** & **Color** \\ \hline
284,291 & 1 & White \\
284,292 & 1 & Beige \\
284,293 & 1 & Blue \\
286,269 & 2 & Brown \\
285,980 & 2 & Black \\
285,989 & 2 & Red \\
286,290 & 1 & Green \\ \hline \hline \end{tabular}
\end{table}
Table 3: T4 Innovation prototypes and typologies.  
Figure 5: Structure of the devised triple-layer thermo-insulated fabric.  
In order to confer the final quality characteristics, the raw fabric from the loom was finally subjected to the following appropriate finishing operations:  
* Cleaning, i.e., the removal of impurities from the semi-finished product.
* Trimming, wetting-back, steaming and reeling; these operations confer the finished product a specific appearance or a particular hand to meet specific requirements of use or fashion. Moreover, they increase the resistance of the finished product to external physical, chemical or biological agents.  
Figure 7 shows two of the seven prototypes of T4 Innovation fabric obtained with, respectively, red-colored and beige-colored yarns.