The thermal conductivity coefficients of the samples were obtained (Fig. 10). The thermal conductivity coefficient of sample A was the highest. The lowest thermal conductivity coefficient was obtained for sample Z2 because of the content of the material used, the pressure applied to the materials and the porosity. Generally,
samples having sunflower stalk with cottony tissue had low heat transfer coefficients. Examples of heat transmission coefficients of less than 0.1 are the S, N, P, and Z samples. Therefore, to study their structure, the compression ratio and the
amount of binder was varied and a much smaller heat transfer coefficient was obtained in these samples. As shown in Fig. 9, the sample with the lowest coefficient of conductivity, 0.0728 W/mK, was the Z2 sample. To reduce the overall heat transfer coefficient of the foam handle portion, sunflower, and cotton wastes were mixed in different proportions. The sunflower stem portion of the volume of the foam has a great amount of space, and empty volumes render a low coefficient of thermal conductivity possible. Some insulating materials produced are shown in cross-section views in Figs. 11 and 12.