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Article

Effects of Refiner Plates with Different Fillings on TMP Properties

by
Hyeong-Hun Park
1,
Chul-Hwan Kim
1,*,
Ji-Su Lee
2 and
Cheong-Ha Lee
2
1
Department of Forest Products, Gyeongsang National University, Jinju 52828, Republic of Korea
2
Department of Environmental Material Sciences, Institute of Agricultural and Life Science (IALS), Gyeongsang National University, Jinju 52828, Republic of Korea
*
Author to whom correspondence should be addressed.
Appl. Sci. 2023, 13(8), 5091; https://doi.org/10.3390/app13085091
Submission received: 20 March 2023 / Revised: 10 April 2023 / Accepted: 17 April 2023 / Published: 19 April 2023
(This article belongs to the Section Applied Industrial Technologies)
Browse Figures
Review Reports Versions Notes

Abstract

:
This study conducted a comparative analysis of two refiner plates that had different bar patterns. The plates were designed with three distinct zones, including the high-intensity zone, the transition zone, and the low-intensity zone, and had a draft angle of 4–5 degrees. The two refiner plates had a significant difference in cutting edge length (CEL) of approximately four times. Specifically, TMP plate A (TP A) had a CEL of 5.1 km/s, while plate B (TP B) had a CEL of 22.7 km/s, indicating that TP A applied greater force to the wood chips during refining. TP A exhibited greater stock throughput at the same refining energy compared to TP B due to its smaller CEL. The low-intensity refining of TP B promoted the fibrillation of TMP fibers, leading to a large decrease in fiber width without significantly changing the mean fiber length before and after refining. The bulk of TMP and CTMP increased slightly more in TP B than in TP A. However, TP A showed a greater decrease in tensile strength due to a larger decrease in fiber length, whereas there was no significant change in tear strength between the two plates.

1. Introduction

Refiner patterns are important in thermomechanical pulping (TMP) because they play a crucial role in the fiber development process, which affects the quality and properties of the resulting pulp. TMP is a process in which wood chips are heated under pressure and then mechanically pulped to separate the fibers. During the refining stage, the fibers are subjected to mechanical shearing forces that break down their structure and improve their bonding ability. Thus, the refining process is considered to be the heart of the papermaking process [1]. Refiner patterns refer to the design and configuration of the refining plates in the refiner, which determine the intensity and direction of the shearing forces applied to the fibers [2].
The refiner pattern affects the properties of the pulp in several ways. For instance, a refiner plate with a more aggressive pattern design characterized by wider grooves and bars can cut fibers to a greater extent. On the other hand, a less aggressive refiner bar pattern has narrower grooves and bars and is designed to prevent fibers from being damaged [3].
In addition to affecting the quality of the pulp, the refiner pattern also has an impact on the energy consumption and operating costs of the refining process. A more aggressive bar pattern may require more power to operate and result in faster wear on the refining plates, while a less aggressive bar pattern may require less power and have a longer lifespan. Therefore, the choice of refiner pattern is an essential consideration for pulp mills to optimize the quality and efficiency of their TMP process [4].
One important factor in the design of refiner plate fillings is the size and shape of the grooves and bars that make up the refiner pattern. Different filling designs can produce varying degrees of fiber fibrillation and pulp quality and affect energy consumption and plate wear. For example, some refiner plates may have a “studded” or “knurled” pattern that creates small, raised bumps on the plate surface. This design can produce a high degree of fiber fibrillation and increase the bonding between the fibers, resulting in a stronger pulp with improved paper properties. Other refiner plates may have a more “corrugated” or “serrated” pattern with larger grooves and ridges that create a more aggressive shearing action on the fibers. This design can produce a higher degree of fiber damage and fines, which may be desirable for certain paper grades but can increase energy consumption and plate wear [5].
The exact design and composition of refiner plate fillings will depend on the specific application and performance requirements of the pulp mill. Pulp mills may work with refiner plate suppliers to develop custom plate designs and fillings that optimize pulp quality, energy consumption, and plate wear [6].
The manufacturing process for refiner plates is complex and requires specialized equipment and expertise. Many pulp mills rely on dedicated suppliers to produce their refiner plates. These suppliers can provide custom designs and ensure consistent quality and performance.
Refiner plate patterns for TMP are typically composed of three main zones: the high-intensity zone, the transition zone, and the low-intensity zone. The high-intensity zone is located at the center of the plate and is characterized by larger and more aggressive grooves and bars. This zone is responsible for the majority of fiber development and fibrillation, which increase the bonding between the fibers and improve the strength and stiffness of the resulting paper. The high-intensity zone is also associated with higher energy consumption and plate wear. The transition zone surrounds the high-intensity zone and has a less aggressive pattern with smaller grooves and ridges. This zone helps to gradually transition the fibers from the high-intensity zone to the low-intensity zone, reducing the likelihood of fiber damage or over-refining. The low-intensity zone is located at the outer edges of the plate and has a smoother and less aggressive pattern than the high-intensity zone. This zone is responsible for refining any remaining fibers and producing a smooth and even surface on the pulp. The low-intensity zone is associated with lower energy consumption and plate wear.
The specific design and composition of the three zones may vary depending on the specific application and performance requirements of the pulp mill. However, the concept of dividing the refiner plate into three zones is a common approach used in TMP refining to optimize pulp quality and efficiency [6,7].
It is important to study the refining effects of refiner plates with different fillings on TMP properties in order to optimize the performance of the refining process and the quality of the resulting pulp. Refining is a critical step in the pulp and paper production process in which wood chips or other raw materials are mechanically treated to break down the fibers and improve their properties. This knowledge can help pulp mills select the optimal refiner plate design for their specific application to achieve the desired pulp quality and production efficiency. Additionally, by optimizing the refining process via the selection of appropriate refiner plates, mills will be able to improve the efficiency of the process, reduce energy consumption, and extend the lifespan of their equipment. In this study, two TMP refiner plates with high and low intensity were designed to compare the refining effects on TMP properties to ensure efficient and high-quality pulp production in the pulp and paper industry. These plates differed in the number of bars, the dimensions of the bars, and the design of the three refining zones on the plate.

2. Materials and Methods

2.1. Raw Materials

Pinus densiflora, commonly known as the Korean red pine, is widely used for thermomechanical pulping (TMP) in Korea. Pinus densiflora is known for its favorable properties for TMP, such as its relatively high density, low extractives, and high cellulose content. Jeonju Paper Co. Ltd. in Jeonju city, Korea supplied the wood chips of Pinus densiflora for the experiment. Table 1 shows the physicochemical characteristics of wood chips analyzed by TAPPI T 203 [8], ISO/DIS 21436 [9], ISO 14453 [10] and ISO 1762 [11].

2.2. Wood Chip Pretreatment

The wood chips used for TMP and CTMP were in the range of 4–6 mm in length and 2–3 mm in thickness. The wood chips were processed in the order of washing, soaking, and steaming. During the chip washing stage, the surface of the wood chips and the foreign substances that entered with the chips were removed by directly washing them with water. In the chip soaking stage, the washed chips were completely immersed in water at around 40 °C overnight to adjust the average moisture content of the wood chips to 50–55%. In the steam pretreatment stage, a laboratory digester (Duko, Daejeon city, Republic of Korea) was used to soften the chips with steam for about 10 min at 100 °C with a liquor-to-wood ratio of 2:1 to soften them at a high temperature.

2.3. Chemical Treatment for Preparing CTMP

For the preparation of CTMP (chemithermomechanical pulp), the laboratory digester (Duko, Republic of Korea) was used to impregnate the wood chips with a liquor-to-wood ratio of 4:1. The liquor, including NaOH (Special grade, Samchun Chemicals, Pyeongtaek city, Republic of Korea) and Na2SO3 (Special grade, Samchun Chemicals, Pyeongtaek city, Republic of Korea), was added at 3% each based on the oven-dried weight of the wood chip. The impregnation time in the digester was set at 60 min at 100 °C.

2.4. Manufacturing Procedure of Refiner Plates via Sand Casting

Refiner plates were made by sand casting using the following steps: plate molds with desired patterns and dimensions were created based on the drawings designed in AutoCAD. The patterns were made slightly larger than the final products to account for thermal contraction or shrinkage. The pattern molds were placed in flasks filled with resin-coated sand. Once the sand molds, including copes and drags, solidified, they were removed from the pattern mold, and molten metal was poured into the sand mold through a sprue and runner system. Table 2 displays the elemental composition of TMP refiner plate analyzed using ICP spectrophotometer (ICP-OES, OPTIMA 8300DV, PerkinElmer, Waltham, MA, USA). The composition can vary depending on the specific type of plate and its manufacturer. However, the plates were made of high-chromium white iron alloyed with nickel and molybdenum to improve their wear resistance and toughness.
After the mold was completely cooled, the sand mold was broken away to recover the refiner plates. The casting products were finished via a post-treatment process such as surface grinding and heat treatment at 800–1000 °C. The final refiner plates with different bar patterns for TMP are shown in Figure 1.

2.5. 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:
C E L z o n e   x ( k m / s ) = N r o t o r   x × N s t a t o r   x × L x
CELzone x = cutting edge length at zone x
Nrotor x = Total bar no. of the rotor in one revolution
Nstator x = Total bar no. of the stator in one revolution
Lx = Bar 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.
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.

2.6. Refining and Screening

The pretreated wood chips for TMP and CTMP were refined using a laboratory single disc refiner (KOS1, Republic of Korea) (refer to Figure 3), and the gap clearance between the stator and rotator of the refiner was set to approximately 0.6–0.8 mm. The stock discharged at each refining stage was steamed using an autoclave (DS-PAC40, Dongseo Science, Dangjin city, Republic of Korea) at 120 °C for 10 min before the next refining. Refining was performed three times for each chip at 1500 rpm. Refining energy consumed during refining was calculated by measuring the cumulative power consumption (kWh/t) using a Multi-Function Digital Power Meter (MPM330, Daebung E&C Co., Ltd., Seoul, Republic of Korea).
The final pulp stock’s consistency was adjusted to 1.57 ± 0.04% after refining to enable further beating with a 5.5 kg weight on the Valley beater for around 10 min. The final freeness was about 150 mL CSF, as measured according to ISO 5267-2 [14].
The specific refining energy (SRE), measured in kWh per ton, and stock throughput were calculated based on ISO/TR 11371 [13]. Specifically, the time and power required for the supplied raw material to pass through the refiner plate were recorded, and the SRE was calculated using the amount of raw material discharged during that time, as shown in Equation (2):
S R E   ( k W h / t ) = P t o t − P 0 f × c
where SRE represents the specific refining energy, Ptot denotes the total load power (kW), P0 represents the no-load power (kW), f represents the amount of the stock that passed through the refiner per unit of time (m3/h), and c represents the stock consistency measured in tons per cubic meter (t/m3).
The shive content in TMP and CTMP after refining was determined according to TAPPI Test Method T 275. A 50 g sample from the refined pulp was taken based on the oven-dried weight and classified into shives and disintegrated fibers using the Somerville screen (Daeil Machinery Co., Daejeon, Republic of Korea) with a slot width of 0.15 mm for 30 min. The fibers passing through the screen were collected for subsequent use in preparing handsheets, and the shives left on the screen were dried, weighed, and used to calculate the shive content.

2.7. Measurement of Physical and Optical Properties of TMP and CTMP

The mean fiber length and fines content of TMP and CTMP were measured using Fiber Quality Analyzer (FQA-360, OpTest Equipment Inc. Hawkesbury, ON, Canada). To measure the physical and optical properties of TMP and CTMP, handsheets with a basis weight of 60 g/m2 were prepared according to ISO 5269-1. Physical properties of the pulps included tensile strength (ISO 1924-2 [15]), tear strength (ISO 1974 [16]), and bulk (ISO 534 [17]), and optical properties included brightness (ISO 2470-1 [18]) and opacity (ISO 2471 [19]).

3. Results and Discussion

3.1. Comparison of Refining Energy and Stock Throughput from the Refiner Plates with Different Patterns

Figure 4 presents the effect of increasing refining energy on stock throughput for TMP and CTMP during the refining of wood chips using TP A and TP B with different plate patterns. The results indicate that, initially, there was no significant difference in stock throughput between TP A and TP B regardless of their plate patterns. However, as severe defibration occurred, more pulp stock began to be discharged from TP A with a smaller CEL at the same refining energy compared to TP B. The high-intensity refining of TP A could cause a significant reduction in chip size, which could lead to better fiber separation during the subsequent refining stages. As a result, more fibers could be extracted from a given amount of wood chips, which might increase the overall yield of mechanical pulp. Finally, it contributed to a greater reduction in energy consumption during the subsequent refining stages, as the smaller chip size allowed for more efficient refining.
These findings are consistent with the previous studies that have demonstrated the effect of plate pattern and refining intensity on pulp quality and energy consumption [20,21]. High-intensity refining for TMP, as performed by TP A, has been shown to improve pulp productivity and reduce energy consumption by promoting defibration and reducing the refining time consumed up to the final freeness [22,23].

3.2. Comparison of Fiber Properties of TMP and CTMP Prepared by the Plates with Different Patterns

Table 6 provides a comparative analysis of the fiber properties between TMP and CTMP that were produced using refiner plates with different patterns. The results indicate significant differences in mean fiber length, fines content, fiber width, and coarseness between TMP and CTMP. High intensity refining by TP A with a smaller CEL led to a greater loss of fiber length than TP B in the case of TMP, resulting in increased fines. Moreover, more fibrillations occurred from the fiber walls, leading to greater reductions in fiber width and coarseness. This suggests that the fiber properties of TMP are significantly influenced by the difference in plate patterns [24,25,26,27]. It was confirmed that, although the refiner plates were not made for TMP and the raw materials were mixed pulps with softwood and hardwood bleached kraft pulp, the smaller CEL of TP A tends to make fiber length and fines content, respectively, short and low [28].
However, CTMP was produced from pretreated wood chips using alkali-based chemicals, which resulted in a different behavior compared to TMP. Therefore, the difference in refiner plate patterns did not have a significant effect on CTMP fiber properties. It was confirmed that, when refining was performed on softened wood tissue, the plate pattern did not show significant differences in fiber characteristics such as length, fines, width, and coarseness [29,30,31]. That is, CTMP was rarely affected by a plate pattern differently to TMP.

3.3. Comparison of Shive Contents of TMP and CTMP Made by the Plates with Different Patterns

Figure 5 indicates that there was no remarkable difference in shive contents between TP A and TP B, suggesting that different plate patterns had no noticeable effect on shives left in both TMP and CTMP at the same freeness level. Shives are relatively large particles or bundles of fibers, and it was assumed that they might not be as sensitive to changes in plate pattern as other types of contaminants or fines. Furthermore, other factors, such as the type and quality of the raw materials used in mechanical pulp production, the refining conditions, and the overall pulp processing methods, may greatly influence shive content compared to plate pattern alone.
In contrast, the shive content of CTMP was up to 1.66% lower than that of TMP, likely due to the use of NaOH and Na2SO3 in the CTMP impregnation stage, which could soften lignin and hemicellulose and make fibers more easily separated during refining.

3.4. 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 chemithermomechanical 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 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. However, the results showed that no remarkable difference was observed in TMP’s tear strength between TP A and TP B. These findings suggest that factors other than fiber length should be considered in determining the tear strength of TMP.

3.5. Comparison of Optical Properties of TMP and CTMP Made by the Plates with Different Patterns

The optical properties of TMP and CTMP prepared by the plates with different patterns were compared in Figure 8. Interestingly, no meaningful changes were observed in the brightness and opacity of TMP and CTMP made from the same raw materials despite a large difference in CEL between TP A and TP B. The final brightness of TMP and CTMP is influenced by various factors such as the wood species, the refining temperature, the chemical additives used during pulping, and the bleaching process. However, in this study, there was no difference in brightness between TMP and CTMP for each plate pattern because there was no difference in pulp conditions except for the plate pattern. In unbleached mechanical pulps, the fibers are much shorter and coarser than those in chemical pulps. The fibers are also less uniform in size and shape, affecting their light scattering ability. Therefore, the difference in opacity between unbleached mechanical pulps is typically small unless there is a significant difference in fiber length and fines content. This suggests that the pattern change in the refiner plates does not play an important role in determining the optical properties of mechanical pulps without greatly affecting fiber dimensions. Rather, it was thought that it would be difficult to expect a difference in the opacity of mechanical pulps unless the refining intensity was adjusted via changes in operating conditions such as the gap of the refiner plate.

4. Conclusions

Two refiner plates with different bar patterns were designed to have three distinct zones: the high-intensity zone, the transition zone, and the low-intensity zone. The high-intensity zone is composed of longer bars with fewer numbers, whereas the transition zone has fewer bars, but the bars are longer. The low-intensity zone has the highest number of bars with the shortest bar length. TP A with a smaller CEL was able to make more stock throughput at the same refining energy compared to TP B, due to its high-intensity refining in TMP and CTMP. The difference in the plate patterns greatly affected the fiber properties of TMP, such as mean fiber length, fines content, fiber width, and coarseness, but had no meaningful effect on CTMP. Shive contents were also found to not be influenced by the plate pattern, while the bulk and tensile strength of both TMP and CTMP were affected. Refining with TP B resulted in a decrease in tensile strength with an increase in bulk. However, the different patterns of the plates rarely influenced tear strength. The study concluded that the patterns of the refiner plate could be an essential factor in saving refining energy in producing TMP and CTMP.

Author Contributions

Research and investigation, C.-H.K., H.-H.P., J.-S.L. and C.-H.L.; tables and figures preparation, J.-S.L. and C.-H.L.; writing—review and editing, H.-H.P. and C.-H.K. All authors have read and agreed to the published version of the manuscript.

Funding

This research was supported by the Basic Science Research Program via the National Research Foundation of Korea (NRF) funded by the Ministry of Education (No. 2022R1I1A3053045).

Acknowledgments

The authors thank the KOS1 officials for helping to manufacture the refiner plate.

Conflicts of Interest

The authors declare no conflict of interest.

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Applsci 13 05091 g001 550
Figure 1. TMP refiner plates with different bar patterns.
Figure 1. TMP refiner plates with different bar patterns.
Applsci 13 05091 g001
Applsci 13 05091 g002 550
Figure 2. Zone classification of the plates based on bar lengths.
Figure 2. Zone classification of the plates based on bar lengths.
Applsci 13 05091 g002
Applsci 13 05091 g003 550
Figure 3. Single disk refiner fitted with TMP plates.
Figure 3. Single disk refiner fitted with TMP plates.
Applsci 13 05091 g003
Applsci 13 05091 g004 550
Figure 4. Stock throughput of different plates with distinctive patterns.
Figure 4. Stock throughput of different plates with distinctive patterns.
Applsci 13 05091 g004
Applsci 13 05091 g005 550
Figure 5. Shive contents of TMP and CTMP prepared by different plates with distinctive patterns.
Figure 5. Shive contents of TMP and CTMP prepared by different plates with distinctive patterns.
Applsci 13 05091 g005
Applsci 13 05091 g006 550
Figure 6. Change in bulk of TMP and CTMP prepared from the plates with distinctive patterns.
Figure 6. Change in bulk of TMP and CTMP prepared from the plates with distinctive patterns.
Applsci 13 05091 g006
Applsci 13 05091 g007 550
Figure 7. Change in tensile and tear index bulk of TMP and CTMP prepared from the plates with distinctive patterns (tensile strength of TMP and CTMP are significantly different at p ≤ 0.05 according to Tukey’s multiple comparison tests).
Figure 7. Change in tensile and tear index bulk of TMP and CTMP prepared from the plates with distinctive patterns (tensile strength of TMP and CTMP are significantly different at p ≤ 0.05 according to Tukey’s multiple comparison tests).
Applsci 13 05091 g007
Applsci 13 05091 g008 550
Figure 8. Brightness and opacity of TMP and CTMP prepared from the plates with distinctive patterns.
Figure 8. Brightness and opacity of TMP and CTMP prepared from the plates with distinctive patterns.
Applsci 13 05091 g008
Table
Table 1. Physicochemical characteristics of Pinus densiflora (Unit: %).
Table 1. Physicochemical characteristics of Pinus densiflora (Unit: %).
α-CelluloseHemicelluloseLigninExtractivesAsh
39.326.131.72.10.95
Table
Table 2. Elemental composition of refiner plate.
Table 2. Elemental composition of refiner plate.
ElementsCSiMnPSNiCrVMo
Wt, %1.061.120.920.030.011.6117.40.410.76
Table
Table 3. Specification of two refiner plates with different patterns.
Table 3. Specification of two refiner plates with different patterns.
TMP Plate A (TP A)TMP Plate B (TP B)
3D designApplsci 13 05091 i001Applsci 13 05091 i002
Distinctive plate zonesApplsci 13 05091 i003Applsci 13 05091 i004
Bars with a draft angle of 4°Applsci 13 05091 i005Applsci 13 05091 i006
Table
Table 4. Bar dimension in each zone of two refiner plates with different patterns.
Table 4. Bar dimension in each zone of two refiner plates with different patterns.
TMP Plate A (TP A)TMP Plate B (TP B)
Low-intensity
zone		Applsci 13 05091 i007Applsci 13 05091 i008
Chip
transition
zone		Applsci 13 05091 i009Applsci 13 05091 i010
High-intensity
zone		Applsci 13 05091 i011Applsci 13 05091 i012
Bar angle (°)52
Table
Table 5. CEL calculation of two plates with different patterns.
Table 5. CEL calculation of two plates with different patterns.
TMP Plate A (TP A)TMP Plate B (TP B)
ZoneBar ShapeBar No.Bar Length
(mm)		ZoneBar ShapeBar No.Bar Length
(mm)
Low-intensity zoneZone 1Applsci 13 05091 i01315610Zone 1Applsci 13 05091 i01436019
Zone 2Applsci 13 05091 i0152646
Chip transition
zone		Zone 2Applsci 13 05091 i01615620Zone 3Applsci 13 05091 i01714422
Zone 4Applsci 13 05091 i018966
High-intensity
zone		Zone 3Applsci 13 05091 i0196023Zone 5Applsci 13 05091 i020489.5
Zone 4Applsci 13 05091 i0213010Zone 6Applsci 13 05091 i0222410.5
Total no. of bars502936
CEL (km/s)5.122.7
Table
Table 6. Comparison of fiber properties according to the different plates.
Table 6. Comparison of fiber properties according to the different plates.
TMPCTMP
TP ATP BTP ATP B
Length-weighted mean fiber length (mm)0.46 ± 0.080.56 ± 0.140.49 ± 0.130.45 ± 0.03
Fines content (%)27.7 ± 4.3721.0 ± 6.6025.3 ± 0.6825.2 ± 0.78
Fiber width (μm)37.1 ± 2.526.6 ± 9.938.8 ± 0.338.9 ± 0.6
Coarseness (mg/m)1.25 ± 0.100.79 ± 0.230.89 ± 0.040.85 ± 0.27
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Park, H.-H.; Kim, C.-H.; Lee, J.-S.; Lee, C.-H. Effects of Refiner Plates with Different Fillings on TMP Properties. Appl. Sci. 2023, 13, 5091. https://doi.org/10.3390/app13085091

AMA Style

Park H-H, Kim C-H, Lee J-S, Lee C-H. Effects of Refiner Plates with Different Fillings on TMP Properties. Applied Sciences. 2023; 13(8):5091. https://doi.org/10.3390/app13085091

Chicago/Turabian Style

Park, Hyeong-Hun, Chul-Hwan Kim, Ji-Su Lee, and Cheong-Ha Lee. 2023. "Effects of Refiner Plates with Different Fillings on TMP Properties" Applied Sciences 13, no. 8: 5091. https://doi.org/10.3390/app13085091

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