# Effects of Refiner Plates with Different Fillings on TMP Properties
## 3 Results and Discussion
### Comparison of Physical Properties of TMP and CTMP Made by the Plates with Different Patterns  
Figure 5 is a graph that compares the bulk of thermomechanical pulp (TMP) and chemitherromechanical pulp (CTMP) prepared with TP A and TP B with different patterns. The bulk of TMP and CTMP refined by TP B with a greater CEL was found to be slightly larger. The TMP bulk had a \(p\)-value greater than 0.05, indicating that there was no significant difference between TP A and TP B. However, the CTMP bulk showed a significant difference between TP A and TP B, as the \(p\)-value from ANOVA analysis was less than 0.05. The bulk of TMP and CTMP is an essential factor in determining the physical properties of paper and paperboard, such as thickness, porosity, and stiffness. It was also known that increasing the bulk of paperboard resulted in improved bending stiffness and surface smoothness while reducing the compressive strength and burst index [32]. TMP is typically produced at higher temperatures and pressures than CTMP, resulting in greater fiber bonding and denser sheets. As a result, paper and paperboard made from TMP generally have lower bulk and higher density than those made from CTMP (refer to Figure 6). CTMP, on the other hand, has a lower degree of fiber bonding and a higher degree of flexibility than TMP. This makes it easier to increase the bulk of paper and paperboard made from CTMP \begin{table}
\begin{tabular}{c c c c c} \hline  & **TMP** & \multicolumn{2}{c}{**CTMP**} \\ \hline  & **TP A** & **TP B** & **TP A** & **TP B** \\ \hline Length-weighted mean fiber & & & & \\ length (mm) & 0.46 \(\pm\) 0.08 & 0.56 \(\pm\) 0.14 & 0.49 \(\pm\) 0.13 & 0.45 \(\pm\) 0.03 \\ \hline Fines content (\%) & 27.7 \(\pm\) 4.37 & 21.0 \(\pm\) 6.60 & 25.3 \(\pm\) 0.68 & 25.2 \(\pm\) 0.78 \\ \hline Fiber width (\(\mu\)m) & 37.1 \(\pm\) 2.5 & 26.6 \(\pm\) 9.9 & 38.8 \(\pm\) 0.3 & 38.9 \(\pm\) 0.6 \\ \hline Coarseness (mg/m) & 1.25 \(\pm\) 0.10 & 0.79 \(\pm\) 0.23 & 0.89 \(\pm\) 0.04 & 0.85 \(\pm\) 0.27 \\ \hline \end{tabular}
\end{table} 
Table 6: Comparison of fiber properties according to the different plates. Figure 5: Shive contents of TMP and CTMP prepared by different plates with distinctive patterns. by increasing the refining level and refining time, which can create a more open, fluffy structure [33; 34]. The effect of plate patterns on the tensile strength of TMP and CTMP is compared in Figure 7. The results showed that the use of TP B, with a larger CEL, had a negative effect on the tensile strength of both TMP and CTMP. This finding is consistent with previous research that has shown the importance of plate patterns on pulp properties, including tensile strength [34; 35; 36]. Interestingly, the study also found that, unlike the refining for stock preparation in the papermaking process, a plate with a smaller CEL is more advantageous for developing the tensile strength of mechanical pulp. Both the TMP and CTMP tensile strengths had \(p\)-values less than 0.05, indicating a significant difference between TP A and TP B. This suggests that the plate patterns used in mechanical pulp production can have a significant impact on the resulting pulp properties and the quality of paper or paperboard produced from it. The tear strength of TMP and CTMP demonstrated a different behavior compared to their tensile strength. Even when the pattern of the refiner plate was changed, there was no significant impact on the tear strength of either TMP or CTMP. Despite a notable variation in the refiner plate pattern, with a CEL difference of approximately four times, the mechanical pulp's tear strength exhibited negligible changes in both TMP and CTMP. In fact, it was readily predicted that CTMP would not be affected because the mean fiber length of pulp fibers prepared from two different plates remained relatively unchanged. Conversely, TMP was expected to differ greatly in tear strength between TP A, producing shorter fibers, and TP B.