# Effects of Refiner Plates with Different Fillings on TMP Properties
## 2 Materials and Methods
### Comparison of Two Refiner Plates with Different Bar Patterns  
Table 3 compares the characteristics of two refiner plates with different bar patterns. Each plate was designed to have three distinguished zones including the high-intensity zone, the transition zone, and the low-intensity zone, and plate A (TP A) was manufactured with a coarser pattern than plate B (TP B). The high-intensity zone is composed of either longer bars, extending from the intermediate zone, or shorter bars and has the fewest number of bars. The transition zone has fewer bars than the low-intensity zone, but the bars are longer. The low-intensity zone has the highest number of bars and the shortest bar length. A draft angle of 4-5 degrees was also given to the bars of the casting plate to prevent damage during the removal of the sand mold from the pattern in the casting process. In general, refiner plates have been manufactured using conventional casting technology, which requires a 3-5 minimum draft angle [12].  
TP A has a wider bar and groove than TP B in the high-intensity zone and low-intensity zone, and the bar height was designed to be the same at 4 mm for both plates (refer to Table 4). In the transition zone, TP B has a 0.5 mm wider groove than TP A.  
In Figure 2, the zones were categorized based on the length of the bars to calculate the cutting edge length (\(CEL\)) of the refiner plates with distinct patterns. This means that the length of the bars in each zone is used to determine the \(CEL\) of the refiner plates, which can affect the refining process in different ways. By categorizing the zones based on the bar length, it is possible to identify the areas where the refining action is the most intense and where the material is subjected to the greatest shear forces. This information can be used to optimize the design of the refiner plates and improve the refining process. The CEL of the refiner plate was calculated according to ISO/TR11371 [13] as follows:  
\[CEL_{zone\;x}(\mathrm{km/s})=N_{rotor\;x}\times N_{stator\;x}\times L_{x} \tag{1}\]  
\begin{table}
\begin{tabular}{c c c} \hline \hline  & **TMP Plate A (TP A)** & **TMP Plate B (TP B)** \\ \hline Low-intensity zone & & \\ \hline Chip transition zone & & \\ \hline High-intensity zone & & \\ \hline Bar angle (\({}^{\circ}\)) & & \\ \hline \hline \end{tabular}
\end{table}
Table 4: Bar dimension in each zone of two refiner plates with different patterns.  
\begin{table}
\begin{tabular}{c c c} \hline \hline  & **TMP Plate A (TP A)** & **TMP Plate B (TP B)** \\ \hline Distinctive plate zones & & \\ \hline Bars with a draft angle of 4\({}^{\circ}\) & & \\ \hline \hline \end{tabular}
\end{table}
Table 3: _Cont._\[CEL_{zone\;x}=cutting\;\text{edge length at zone }x\]  
\[N_{rotor\;x}=Total\;\text{bar no. of the rotor in one revolution}\]  
\[N_{stator\;x}=Total\;\text{bar no. of the stator in one revolution}\]  
\[L_{x}=Bar\;\text{length at zone }x.\]  
Figure 2 illustrates the red reference lines utilized for dividing the zones based on the length of the bars to calculate \(CEL\) in two refiner plates with varying patterns. TP A and TP B were divided into four zones and six zones, respectively. Table 5 presents the measurements of bar number and length for each zone on two refiner plates. TP B was designed to have 1.86 times more bars than TP A. Importantly, TP A was expected to be more effective in high-intensity refining, as evidenced by its \(CEL\) being approximately four times smaller than that of TP B.  
Figure 2: Zone classification of the plates based on bar lengths.  
In TMP refining, a refiner plate pattern with higher _CEL_ implies greater force applied to the wood chips. It was expected that the higher impact might result in more extensive fiber separation and refining, leading to improved pulp quality. However, it can also cause higher energy consumption and increased wear on the refiner plates.