14 Oct,2021
In an experiment before mathematical modeling, we made some sample papers of different compositions and divided them into four groups. We stipulated that sericin and chitosan were not added as the control group; Sericin without chitosan was added in experimental group 1; Chitosan without sericin was added in experimental group 2; both chitosan and sericin was added to group 3. After the paper was produced, we tested the paper in three dimensions: Flatness, Compliance, and Folding endurance. Flatness was used to detect the flatness and smoothness of the paper, measured by the appearance; compliance was used to test the degree of softness and elasticity of paper, as measured by the scratch response; Folding endurance was used to detect the stiffness and brittleness of a paper, as measured by a crease test. During the above tests, eight observers observed the whole experiment. Eight sheets of paper were taken from each group and each sheet was torn into three pieces. A total of 72 sheets were taken from the three groups.
Each observer was given nine pieces of paper from three experimental groups, on average, but the observers did not know which group each piece came from. After observing all the experiments, each observer rated the nine pieces of paper he or she had. The experimental results were presented in the form of observer score, with a full score of 5 and a baseline score of 3 for each item in the control group. After the data is collected, the three scores given by each observer on each set of papers are averaged to obtain the final data point. Through linear fitting by Matlab, 8 data of each group were linearly fitted to obtain approximate evaluation results. The final result is shown below:
In these line-fitting graphs, the a-axis stands for eight observers, and the b-axis stands for the rating score evaluated by each observer. After plotting these points, we used Matlab with the formula to draw the fitting lines. These lines help us estimate the overall trends of observers’ evaluation toward certain properties of a different group of paper.
In conclusion, based on the analysis, we found that the paper with chitosan and sericin had the best evaluations in the perspective of flatness, compliance, and folding endurance, compared with the control group, experimental group 1, and experimental group 2. Therefore, we decided to add both sericin and chitosan in our operated recycled paper.
