# Parametric Analysis of Cylinder Drying Process in Association with Various Materials
## 3 Results and Discussion
### Effects of Transport Materials  
In this section, seven transport materials, consisting of PET, Polyethylene, Polypropylene, Cotton, Wool, Rayon, and Nylon, are investigated in detail at a fixed boundary condition with temperatures of the ambient environment, cloth, and cylinder, being 30 \({}^{\circ}\)C, 40 \({}^{\circ}\)C, and 100 \({}^{\circ}\)C, respectively. The feeding velocity and thickness of the drying material are fixed at 10 m/s and 1 mm, respectively. For computing, the heat transfer process in the drying web, the computational model presented in Section 2.2 is employed.  
The cloth thickness used for drying is divided into eight equal slices. Temperature versus drying time of three layers of 12.5%, 50%, and 87.5% thickness subject to seven different transport materials are presented in Figure 3a-c, respectively. Figure 3d,e illustrate 3D outside temperature profiles of computational models with PET, Wool, and Cotton as drying materials. The results show that the temperatures of the four synthetic fibers of PET, Polyethylene, Polypropylene, and Nylon are similar at any stage of the four phases. For all cases in this section, it is found that the heat transfer of the synthetic fibers is superior to those of the natural fibers, and the heat transfer of the natural fibers is significantly different from each other in the group [3,4]. Specifically, at the same boundary conditions, the temperatures of the synthetic fibers are higher than those of the natural fibers.  
The temperature of cotton is lowest while wool contains the highest temperature in the natural fiber group; however, it is much lower than that of the synthetic fiber group in phases I, II and III. It is noted that in the same drying process, the higher the temperature material is, the faster the water vapor in the drying material is evaporated into the ambient environment; therefore, the smaller the water mass was kept within the drying material, leading to the faster drying process. This phenomenon prevails throughout in the following Sections.  
The higher thermal diffusivities of synthetic fibers relative to those of the natural fibers explains the temperature distributions of different materials in phases I, II, and II as presented in Figure 3. At phase IV, there is no heat supply, and the temperature of the vapor is equal to that of the fabric at the local points as assumed at Section 2.3. In addition, the temperature of a liquid is not changed in an evaporating process; therefore, although the vapor is removed from the drying sheet, the temperature of the sheet is not changed, and the change in temperature of the drying sheet at phase IV is due to the convective heat transfer between the drying cloths and ambient environment. The convective heat transfer is dependent on the heat transfer area, different temperatures, and velocity of the cloths. Note that the heat transfer area in contact with the ambience and the velocity for all materials remain the same. A similar convective heat transfer mechanism prevails except for the temperature difference, thereby the trends look similar.