# Optimization of Technological Parameters of Straw Fiber-Based Plant Fiber Seeding Pot Raw Materials
## 3 Results and Discussion
### Influences of Factors on Z-Direction Tensile Index  
The variance analysis results for Z-direction tensile index (Table 4) indicate that the quadratic regression model could be used to describe the influence of factors on the Z-direction tensile index. Under the confidence level of \(\alpha=0.05\), the fitting equation was significant with an F-value of 47.62 and \(p\)-value less than 0.0001. The lack of fit with \(p\)-value 0.5660 was not significant relative to the pure error, which indicated that the equation fit well. The quadratic regression models could accurately predict the Z-direction tensile index according to the model Equation (2). \[ \begin{array}{l}y_{2}{=2.34+0.91X_{1}-0.12X_{2}+0.09X_{3}+0.04X_{4}-0.19X_{2} {}^{2}-0.13X_{3}{}^{2}}\\ -0.02X_{4}{}^{2}-0.11X_{1}X_{2}+0.04X_{1}X_{4}+0.03X_{2}X_{3}-0.04X_{2}X_{4}-0. 16X_{3}X_{4}\end{array}  \tag{2}\]  
Figure 1: Response surface plot of factors affecting dry tensile index: (**a**) Influence of beating degree of unbleached sulfate conifer pulp fiber and wheat straw fiber quality percentage content on dry tensile index; (**b**) Influence of beating degree of wheat straw fiber and wheat straw fiber quality percentage content on dry tensile index. In Equation (2), \(y_{2}\) represents the Z-direction tensile index (N\(\cdot\)m/g), and \(X_{1}\), \(X_{2}\), \(X_{3}\), and \(X_{4}\) represent the beating degree of unbleached sulfate conifer pulp fiber (\({}^{\circ}\)SR), beating degree of wheat straw fiber (\({}^{\circ}\)SR), wheat straw fiber quality percentage content (%), and film grammage (g/m\({}^{2}\)), respectively. By comparing the \(p\)-values, it was found that the beating degree of unbleached sulfate conifer pulp fiber and beating degree of wheat straw fiber had the highest influence on the Z-direction tensile index, with the smallest \(p\)-value. This was followed by the beating degree of unbleached sulfate conifer pulp fiber, the beating degree of wheat straw fiber, and the wheat straw fiber quality percentage content. The interactive effect between the beating degree of unbleached sulfate conifer pulp fiber and the beating degree of wheat straw fiber was significant, as the \(p\)-value was 0.0235. The interactive effect between the wheat straw fiber quality percentage content and the film grammage was highly significant, with a \(p\)-value of 0.0021. The 3D interaction response graph of the beating degree of unbleached sulfate conifer pulp fiber and the beating degree of wheat straw fiber on the Z-direction tensile index is shown in Figure 2a. The Z-direction tensile index increased with the increasing beating degree of unbleached sulfate cone pulp fiber, which was due to the fact that in the beating degree within the experimental range, after wood pulp fiber was processed, the degree of fiber splitting broom increased with the increasing beating degree, and after fiber splitting broom, the bonding force between fibers increased, and both the same fiber and the dissimilar fiber increased, thus increasing the separation force of the fibers between different layers. When the beating degree of wheat straw fiber was at a medium level, the Z-direction tensile index was slightly higher than that at both ends. It was found that when the beating degree of wheat straw fiber was at a medium level, the fine fibers existed on the membrane surface and did not flow away with the water. The fiber splitting degree in this layer was high, which enhanced the fiber-bonding force between the layers, thus enhancing the layering force. When the amount was fixed, the tensile index in the Z-direction increased. The interaction response surface for the Z-direction tensile index between the parameters of film grammage and the wheat straw fiber quality percentage content is shown in Figure 2b. When the content of wheat straw fiber quality percentage was low, the Z-direction tensile index increased with the increase in the film grammage.