Pub Date : 2023-10-30DOI: 10.7584/jktappi.2023.10.55.5.43
Dong Sung Kim, Min Kyum Kim, Yong Joo Sung
This study evaluated the fiberization of waste papers by using dry mill treatment, in order to increase the usability of waste paper. The three waste papers such as old news paper (ONP), old corrugated container (OCC), and old office paper (WL, white ledger) were mechanically treated with knife mill and hammer mill. The effects of the types of milling processes on the fiberization efficiency were evaluated by measuring the fiber fractionation and by observing fibers and flakes using a microscopy. The knife mill treatment showed the effective fiberization for ONP. In case of OCC and WL samples, the hammer mill treatment showed the better performance in terms of fiber disintegration than the knife mill treatment. The hammer mill treatment resulted in the less flake and the higher in fines fraction, which leaded to changes in the CSF. There were many differences in the dry fiberization of waste papers depending on the mill treatment types, the treatment conditions and the types of waste papers.
{"title":"Study of Dry Fiberization of Waste Paper by Using Dry Milling","authors":"Dong Sung Kim, Min Kyum Kim, Yong Joo Sung","doi":"10.7584/jktappi.2023.10.55.5.43","DOIUrl":"https://doi.org/10.7584/jktappi.2023.10.55.5.43","url":null,"abstract":"This study evaluated the fiberization of waste papers by using dry mill treatment, in order to increase the usability of waste paper. The three waste papers such as old news paper (ONP), old corrugated container (OCC), and old office paper (WL, white ledger) were mechanically treated with knife mill and hammer mill. The effects of the types of milling processes on the fiberization efficiency were evaluated by measuring the fiber fractionation and by observing fibers and flakes using a microscopy. The knife mill treatment showed the effective fiberization for ONP. In case of OCC and WL samples, the hammer mill treatment showed the better performance in terms of fiber disintegration than the knife mill treatment. The hammer mill treatment resulted in the less flake and the higher in fines fraction, which leaded to changes in the CSF. There were many differences in the dry fiberization of waste papers depending on the mill treatment types, the treatment conditions and the types of waste papers.","PeriodicalId":52548,"journal":{"name":"Palpu Chongi Gisul/Journal of Korea Technical Association of the Pulp and Paper Industry","volume":"37 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136132550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-30DOI: 10.7584/jktappi.2023.10.55.5.5
Younglae Kim, Feng Xu, Byoung-Uk Cho
Microbeads with a diameter of 500 μm or smaller are used in the production of cosmetic products, such as foam cleansers. To replace the usage of plastic microbeads in cosmetics with ecofriendly alternatives such as cellulose, development of technologies for producing cellulose beads with a diameter of ≤500 μm, particularly reducing their sizes to <100 μm, is crucial. Herein, cellulose beads with a particle size of 30–250 μm were fabricated via spray method using a coaxial needle and tetraethylammonium hydroxide/urea/cellulose solution. Reduced inner diameter of the needle and increased air pressure decreased the cellulose bead size. Furthermore, the results show that the dispersibility of cellulose beads can be improved by dispersing them in a solvent with low surface tension and employing a gradual drying method, such as air drying.
{"title":"Particle Size and Dispersion Properties of Cellulose Beads Fabricated via Coaxial Needle Spray Method","authors":"Younglae Kim, Feng Xu, Byoung-Uk Cho","doi":"10.7584/jktappi.2023.10.55.5.5","DOIUrl":"https://doi.org/10.7584/jktappi.2023.10.55.5.5","url":null,"abstract":"Microbeads with a diameter of 500 μm or smaller are used in the production of cosmetic products, such as foam cleansers. To replace the usage of plastic microbeads in cosmetics with ecofriendly alternatives such as cellulose, development of technologies for producing cellulose beads with a diameter of ≤500 μm, particularly reducing their sizes to <100 μm, is crucial. Herein, cellulose beads with a particle size of 30–250 μm were fabricated via spray method using a coaxial needle and tetraethylammonium hydroxide/urea/cellulose solution. Reduced inner diameter of the needle and increased air pressure decreased the cellulose bead size. Furthermore, the results show that the dispersibility of cellulose beads can be improved by dispersing them in a solvent with low surface tension and employing a gradual drying method, such as air drying.","PeriodicalId":52548,"journal":{"name":"Palpu Chongi Gisul/Journal of Korea Technical Association of the Pulp and Paper Industry","volume":"100 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136132559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-30DOI: 10.7584/jktappi.2023.10.55.5.52
So Hyun Kim, Myung Suk Shin, Joung Eun Kim, Soon Hwa Kwon, Yong Joo Sung
The high water content of citrus pomace and the high contents of fine particles and soluble materials result in the limited usability of the citrus pomace such as the low-value feed for cow. In order to use citrus pomace as a valuable organic material for various industrial applications, the proper liquid-solid separation process is necessarily required. In this study, the efficient solid-liquid separation methods to solve this problem were investigated. The compression press device and the centrifugal device showed lower separation efficiency than that of the screw press device. The low separation yield of the screw press device was increased by the addition of biomass particles as bulking agents. Fibrous biomass bulking agents made with BKP, ONP, and OCC resulted in the higher efficiency of the solid-liquid separation and lower concentration of the liquid extract. Some flocculants were applied to increase the separation efficiency of the fine solid particles from the liquid extract. The addition of cationic PAM resulted in the coagulation of fine particles and the effective removal of fines in the liquid extract.
{"title":"A Study on the Liquid-solid Separation Properties of Citrus Pomace","authors":"So Hyun Kim, Myung Suk Shin, Joung Eun Kim, Soon Hwa Kwon, Yong Joo Sung","doi":"10.7584/jktappi.2023.10.55.5.52","DOIUrl":"https://doi.org/10.7584/jktappi.2023.10.55.5.52","url":null,"abstract":"The high water content of citrus pomace and the high contents of fine particles and soluble materials result in the limited usability of the citrus pomace such as the low-value feed for cow. In order to use citrus pomace as a valuable organic material for various industrial applications, the proper liquid-solid separation process is necessarily required. In this study, the efficient solid-liquid separation methods to solve this problem were investigated. The compression press device and the centrifugal device showed lower separation efficiency than that of the screw press device. The low separation yield of the screw press device was increased by the addition of biomass particles as bulking agents. Fibrous biomass bulking agents made with BKP, ONP, and OCC resulted in the higher efficiency of the solid-liquid separation and lower concentration of the liquid extract. Some flocculants were applied to increase the separation efficiency of the fine solid particles from the liquid extract. The addition of cationic PAM resulted in the coagulation of fine particles and the effective removal of fines in the liquid extract.","PeriodicalId":52548,"journal":{"name":"Palpu Chongi Gisul/Journal of Korea Technical Association of the Pulp and Paper Industry","volume":"100 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136132557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-30DOI: 10.7584/jktappi.2023.10.55.5.75
Do-Young Lee, Na-Young Kang, Ji-Eun Cha, Hyoung-Jin Kim
Electrospinning is widely recognized as an efficient method for producing continuous nanoscale fibers by overcoming the surface tension of polymer solutions through repulsive forces. Cellulose, a naturally derived, non-toxic, and biodegradable material, has gained attention as an environmentally friendly alternative to petroleum-based materials. The characteristics of the electrospinning solution, such as concentration, viscosity, and surface tension, significantly influence the formation and morphology of electrospun nanofibers (ECNFs). Therefore, controlling the properties of the solution is crucial for producing the desired fiber morphology. In this study, we prepared electrospinning solutions using a mixture of carboxymethyl cellulose (CMC), a water-soluble cellulose derivative, and polyvinyl alcohol (PVA) at various concentrations. The solutions were characterized by measuring their shear viscosity, surface tension, and conductivity. With increasing polymer concentration, viscosity, surface tension, and conductivity showed an upward trend. Additionally, the viscosity exhibited a decreasing trend with increasing spindle speed, rpm. The results were correlated with the diameter of the resulting ECNFs.
{"title":"Analysis of Formation and Characterization of Electrospun Fibers of Carboxymethyl Cellulose/Poly (vinyl alcohol) Polymer Solution","authors":"Do-Young Lee, Na-Young Kang, Ji-Eun Cha, Hyoung-Jin Kim","doi":"10.7584/jktappi.2023.10.55.5.75","DOIUrl":"https://doi.org/10.7584/jktappi.2023.10.55.5.75","url":null,"abstract":"Electrospinning is widely recognized as an efficient method for producing continuous nanoscale fibers by overcoming the surface tension of polymer solutions through repulsive forces. Cellulose, a naturally derived, non-toxic, and biodegradable material, has gained attention as an environmentally friendly alternative to petroleum-based materials. The characteristics of the electrospinning solution, such as concentration, viscosity, and surface tension, significantly influence the formation and morphology of electrospun nanofibers (ECNFs). Therefore, controlling the properties of the solution is crucial for producing the desired fiber morphology. In this study, we prepared electrospinning solutions using a mixture of carboxymethyl cellulose (CMC), a water-soluble cellulose derivative, and polyvinyl alcohol (PVA) at various concentrations. The solutions were characterized by measuring their shear viscosity, surface tension, and conductivity. With increasing polymer concentration, viscosity, surface tension, and conductivity showed an upward trend. Additionally, the viscosity exhibited a decreasing trend with increasing spindle speed, rpm. The results were correlated with the diameter of the resulting ECNFs.","PeriodicalId":52548,"journal":{"name":"Palpu Chongi Gisul/Journal of Korea Technical Association of the Pulp and Paper Industry","volume":"37 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136132551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-30DOI: 10.7584/jktappi.2023.10.55.5.83
Yong Ju Lee, Ji Eun Lee, Jae Gyoung Gwon, Tai Ju Lee, Hyoung Jin Kim
The objective of this study is to apply FTIR and machine learning models for the quantitative analysis of the degree of substitution of cellulose acetate. The models used for the degree of substitution analysis include PCA (principal component analysis), PLS-DA (partial least squares discriminant analysis), SVM (support vector machine), and KNN (k-nearest neighbor). The critical findings of this study indicated that it is possible to analyze the degree of substitution for cellulose acetate with a degree of substitution of 2.0 or less using IR spectrum data derived from acetylation, estimated through PCA. The decrease in explanatory power for degrees of substitution higher than 2.0 can be attributed to the chemical reaction rate. However, by applying SVM and utilizing the kernel trick to project the data into a high-dimensional feature space and perform non-linear classification, it was possible to create a degree of substitution discrimination model with excellent performance, regardless of the degree of substitution. As a result, the model for analyzing the degree of substitution of polymer monomers based on machine learning and IR spectrum data was proposed. It is believed that this model can efficiently replace existing analytical methods.
{"title":"Predictive Modeling for Degree of Substitution of Cellulose Acetate using Infrared Spectroscopy and Machine Learning","authors":"Yong Ju Lee, Ji Eun Lee, Jae Gyoung Gwon, Tai Ju Lee, Hyoung Jin Kim","doi":"10.7584/jktappi.2023.10.55.5.83","DOIUrl":"https://doi.org/10.7584/jktappi.2023.10.55.5.83","url":null,"abstract":"The objective of this study is to apply FTIR and machine learning models for the quantitative analysis of the degree of substitution of cellulose acetate. The models used for the degree of substitution analysis include PCA (principal component analysis), PLS-DA (partial least squares discriminant analysis), SVM (support vector machine), and KNN (k-nearest neighbor). The critical findings of this study indicated that it is possible to analyze the degree of substitution for cellulose acetate with a degree of substitution of 2.0 or less using IR spectrum data derived from acetylation, estimated through PCA. The decrease in explanatory power for degrees of substitution higher than 2.0 can be attributed to the chemical reaction rate. However, by applying SVM and utilizing the kernel trick to project the data into a high-dimensional feature space and perform non-linear classification, it was possible to create a degree of substitution discrimination model with excellent performance, regardless of the degree of substitution. As a result, the model for analyzing the degree of substitution of polymer monomers based on machine learning and IR spectrum data was proposed. It is believed that this model can efficiently replace existing analytical methods.","PeriodicalId":52548,"journal":{"name":"Palpu Chongi Gisul/Journal of Korea Technical Association of the Pulp and Paper Industry","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136132552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-30DOI: 10.7584/jktappi.2023.10.55.5.61
Yong Ju Lee, Soon Wan Kweon, Jae Hyeop Kim, Ji Eun Cha, Kwang-Ho Kang, Hyoung Jin Kim
The objective of this study was exploring the impact of spectral data preprocessing techniques on the performance of machine learning models for classifying the origin of mulberry bast fibers. The findings indicated that a selective spectral region (1800-1200 cm-1) significantly improves classification model performance. Among the classifiers tested, Partial Least Squares Discriminant Analysis (PLS-DA) and Support Vector Machines (SVM) demonstrated the highest accuracy. Additionally, A spectral preprocessing with the Norris-Williams algorithm effectively improved model performance within the same classifier for this dataset. These results suggest that applying machine learning modeling with spectral preprocessing can enable the origin classification of mulberry bast fibers and provide a chemical basis for classification rules beyond simple categorization.
{"title":"Spectral Preprocessing and Machine Learning Modeling for Discriminating Manufacturing Origins of Mulberry Bast Fiber","authors":"Yong Ju Lee, Soon Wan Kweon, Jae Hyeop Kim, Ji Eun Cha, Kwang-Ho Kang, Hyoung Jin Kim","doi":"10.7584/jktappi.2023.10.55.5.61","DOIUrl":"https://doi.org/10.7584/jktappi.2023.10.55.5.61","url":null,"abstract":"The objective of this study was exploring the impact of spectral data preprocessing techniques on the performance of machine learning models for classifying the origin of mulberry bast fibers. The findings indicated that a selective spectral region (1800-1200 cm-1) significantly improves classification model performance. Among the classifiers tested, Partial Least Squares Discriminant Analysis (PLS-DA) and Support Vector Machines (SVM) demonstrated the highest accuracy. Additionally, A spectral preprocessing with the Norris-Williams algorithm effectively improved model performance within the same classifier for this dataset. These results suggest that applying machine learning modeling with spectral preprocessing can enable the origin classification of mulberry bast fibers and provide a chemical basis for classification rules beyond simple categorization.","PeriodicalId":52548,"journal":{"name":"Palpu Chongi Gisul/Journal of Korea Technical Association of the Pulp and Paper Industry","volume":"100 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136132558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-30DOI: 10.7584/jktappi.2023.10.55.5.96
Hae Min Jo, Soo Hyun Lee, Ji Young Lee, Ro Seong Park
In this study, we attempted to manufacture a scale-up Taylor-flow nanogrinder by compensating the shortcomings of a pilot scale Taylor-flow nanogrinder derived from previous studies. Two types of cellulose nanofibers (CNFs) were prepared depending on the pretreatment using a scale-up Taylor-flow nanogrinder and their characteristics were measured to evaluate the grinding efficiency. The capacity of the grinder cylinder and the mixer increased respectively while increasing the capacity of a scale-up Taylor-flow nanogrinder. The size of the diamond particles electrodeposited on the surface of the stator and rotor, which were the components of the grinder cylinder, and the gap between the stator and rotor were reduced to improve the grinding efficiency. In addition, a multi-stage centrifugal pump was installed to induce a uniform flow of CNF slurry according to the increased grinder capacity. When RE-CNF (refining CNF) was manufactured from refined hardwood bleached kraft pulp (HwBKP) using a scale-up Taylor flow nanogrinder, the average particle size and fiber width decreased and the low shear viscosity decreased as the grinding time increased due to HwBKP fibrillation. However, considering the fiber width's average value and standard deviation, it was concluded that the refining pretreatment was not adequate for this facility. When EN-CNF (enzyme-pretreated CNF) was manufactured from enzyme-pretreated HwBKP using a scale-up Taylor flow nanogrinder, the particle size and fiber width decreased linearly as the enzyme dosage and the grinding time increased simultaneously. In particular, when the grinding was carried out for 5-6 h, the fiber width of EN-CNF decreased to 50 nm or less, and the standard deviation decreased. This meant that enzyme pretreatment was efficient for the manufacture of CNF using a scale-up Taylor-flow nanogrinder. Nevertheless, the optimum enzyme dosage and the grinding time should be confirmed carefully to acquire the desired qualities of EN-CNF.
{"title":"Development of Domestic Taylor-flow Nanogrinder for Manufacturing Cellulose Nanofiber III -Evaluation of Physical Properties of Cellulose Nanofibers Manufactured with Scale-up Taylor-flow Nanogrinder-","authors":"Hae Min Jo, Soo Hyun Lee, Ji Young Lee, Ro Seong Park","doi":"10.7584/jktappi.2023.10.55.5.96","DOIUrl":"https://doi.org/10.7584/jktappi.2023.10.55.5.96","url":null,"abstract":"In this study, we attempted to manufacture a scale-up Taylor-flow nanogrinder by compensating the shortcomings of a pilot scale Taylor-flow nanogrinder derived from previous studies. Two types of cellulose nanofibers (CNFs) were prepared depending on the pretreatment using a scale-up Taylor-flow nanogrinder and their characteristics were measured to evaluate the grinding efficiency. The capacity of the grinder cylinder and the mixer increased respectively while increasing the capacity of a scale-up Taylor-flow nanogrinder. The size of the diamond particles electrodeposited on the surface of the stator and rotor, which were the components of the grinder cylinder, and the gap between the stator and rotor were reduced to improve the grinding efficiency. In addition, a multi-stage centrifugal pump was installed to induce a uniform flow of CNF slurry according to the increased grinder capacity. When RE-CNF (refining CNF) was manufactured from refined hardwood bleached kraft pulp (HwBKP) using a scale-up Taylor flow nanogrinder, the average particle size and fiber width decreased and the low shear viscosity decreased as the grinding time increased due to HwBKP fibrillation. However, considering the fiber width's average value and standard deviation, it was concluded that the refining pretreatment was not adequate for this facility. When EN-CNF (enzyme-pretreated CNF) was manufactured from enzyme-pretreated HwBKP using a scale-up Taylor flow nanogrinder, the particle size and fiber width decreased linearly as the enzyme dosage and the grinding time increased simultaneously. In particular, when the grinding was carried out for 5-6 h, the fiber width of EN-CNF decreased to 50 nm or less, and the standard deviation decreased. This meant that enzyme pretreatment was efficient for the manufacture of CNF using a scale-up Taylor-flow nanogrinder. Nevertheless, the optimum enzyme dosage and the grinding time should be confirmed carefully to acquire the desired qualities of EN-CNF.","PeriodicalId":52548,"journal":{"name":"Palpu Chongi Gisul/Journal of Korea Technical Association of the Pulp and Paper Industry","volume":"100 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136132555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-30DOI: 10.7584/jktappi.2023.10.55.5.24
Soo Hyun Lee, Hae Min Jo, Ji Young Lee
In this study, we evaluated the physical properties and drying efficiency of the virgin pulps and recycled fibers, which were the main raw materials for the manufacture of thin paper grades. We selected hardwood bleached kraft pulp (HwBKP), softwood bleached kraft pulp (SwBKP), recycled liquid crystal display interleaf (LCD interleaf), and recycled steel interleaf (steel interleaf) according to the annual usage, and determined the fiber characteristics and drying efficiency after the stock preparation of the pulps using a laboratory disintegrator or a valley beater. And then the handsheets were made of those pulps to determine their strengths and optical properties. The LCD interleaf showed higher freeness and lower water retention value (WRV) than the steel interleaf because the fibers from the LCD interleaf were longer, wider, and less fibrillated than those from steel interleaf. The fiber length and fines content of SwBKP were higher than those of HwBKP at the same freeness after beating, which was consistent with fiber image observation. The drying efficiency of LCD interleaf was higher than steel interleaf, but the handsheets made of steel interleaf showed higher tensile strength, and lower opacity and light scattering coefficient than those made of LCD interleaf. Considering the lower freeness and higher WRV of steel interleaf, it was thought that the fibers from steel interleaf were more fibrillated than those from LCD interleaf. The drying efficiency was higher for HwBKP than for SwBKP. The handsheets made from SwBKP exhibited higher tensile strength and lower opacity and light scattering coefficient than those made from HwBKP. Therefore, we concluded that if LCD interleaf and HwBKP with excellent drying efficiency are used or steel interleaf and SwBKP with high strength are less refined and used for manufacturing thin papers, drying energy can be reduced effectively in a papermaking process.
{"title":"Evaluation of Physical Properties and Drying Efficiency of the Pulps Used in Thin Paper Production","authors":"Soo Hyun Lee, Hae Min Jo, Ji Young Lee","doi":"10.7584/jktappi.2023.10.55.5.24","DOIUrl":"https://doi.org/10.7584/jktappi.2023.10.55.5.24","url":null,"abstract":"In this study, we evaluated the physical properties and drying efficiency of the virgin pulps and recycled fibers, which were the main raw materials for the manufacture of thin paper grades. We selected hardwood bleached kraft pulp (HwBKP), softwood bleached kraft pulp (SwBKP), recycled liquid crystal display interleaf (LCD interleaf), and recycled steel interleaf (steel interleaf) according to the annual usage, and determined the fiber characteristics and drying efficiency after the stock preparation of the pulps using a laboratory disintegrator or a valley beater. And then the handsheets were made of those pulps to determine their strengths and optical properties. The LCD interleaf showed higher freeness and lower water retention value (WRV) than the steel interleaf because the fibers from the LCD interleaf were longer, wider, and less fibrillated than those from steel interleaf. The fiber length and fines content of SwBKP were higher than those of HwBKP at the same freeness after beating, which was consistent with fiber image observation. The drying efficiency of LCD interleaf was higher than steel interleaf, but the handsheets made of steel interleaf showed higher tensile strength, and lower opacity and light scattering coefficient than those made of LCD interleaf. Considering the lower freeness and higher WRV of steel interleaf, it was thought that the fibers from steel interleaf were more fibrillated than those from LCD interleaf. The drying efficiency was higher for HwBKP than for SwBKP. The handsheets made from SwBKP exhibited higher tensile strength and lower opacity and light scattering coefficient than those made from HwBKP. Therefore, we concluded that if LCD interleaf and HwBKP with excellent drying efficiency are used or steel interleaf and SwBKP with high strength are less refined and used for manufacturing thin papers, drying energy can be reduced effectively in a papermaking process.","PeriodicalId":52548,"journal":{"name":"Palpu Chongi Gisul/Journal of Korea Technical Association of the Pulp and Paper Industry","volume":"100 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136132553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-30DOI: 10.7584/jktappi.2023.10.55.5.34
Ji Yong Lee, Yu-jin Lee, Hyung-Jun So, Yoon-No Lee, Yong Joo Sung
The hot pressed pulp mold is one of the promising packaging materials as an alternative plastic packaging material since the hot pressed pulp mold not only is made with natural wood fibers but also has relatively high mechanical properties and good surface properties. Although the hot pressing drying process of the hot pressed pulp mold could increase strength properties, the bulk and the bulk related properties such as insulation could be deceased. In order to increase the applicability of the hot pressed pulp mold, this study assessed the effects of application of the different types of wood by-product such as bark and leaves, on the bulk and the tensile strength of hot pressed pulp mold. The addition of wood by-products resulted in the increase of bulk but the decrease of tensile strength. The loss of tensile strength was compensated by the addition of starch as a strength additive.
{"title":"Effects of Application of Wood By-products to Hot Pressed Pulp Mold","authors":"Ji Yong Lee, Yu-jin Lee, Hyung-Jun So, Yoon-No Lee, Yong Joo Sung","doi":"10.7584/jktappi.2023.10.55.5.34","DOIUrl":"https://doi.org/10.7584/jktappi.2023.10.55.5.34","url":null,"abstract":"The hot pressed pulp mold is one of the promising packaging materials as an alternative plastic packaging material since the hot pressed pulp mold not only is made with natural wood fibers but also has relatively high mechanical properties and good surface properties. Although the hot pressing drying process of the hot pressed pulp mold could increase strength properties, the bulk and the bulk related properties such as insulation could be deceased. In order to increase the applicability of the hot pressed pulp mold, this study assessed the effects of application of the different types of wood by-product such as bark and leaves, on the bulk and the tensile strength of hot pressed pulp mold. The addition of wood by-products resulted in the increase of bulk but the decrease of tensile strength. The loss of tensile strength was compensated by the addition of starch as a strength additive.","PeriodicalId":52548,"journal":{"name":"Palpu Chongi Gisul/Journal of Korea Technical Association of the Pulp and Paper Industry","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136132554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-30DOI: 10.7584/jktappi.2023.10.55.5.13
Kang-Jae Kim, Jin-Ho Kim, Geunyong Park, Myung-Joon Jeong
This paper introduces a random forest regression model trained with infrared spectral data to predict the carbonyl content of Hanji, a traditional Korean paper. The random forest model demonstrated excellent performance in carbonyl content prediction, surpassing the results obtained from the partial least squares model. To optimize the infrared spectral range for prediction, the spectral range was restricted from the entire range of 4000-400 cm-1 to the narrower range of 1800-1200 cm-1, known for its suitability in characterizing paper properties. This limitation enhanced the coefficients of determination of the model, increasing it from 0.921 to 0.937. A permutation variable importance measure was then applied to identify the key spectral regions contributing to carbonyl content prediction. The analysis pinpointed the 1650-1350 cm-1 range as a crucial region for accurate predictions. Subsequently, a new prediction model was built using data exclusively from this important region, yielding remarkably improved coefficients of determination of 0.960 and 0.965 for the raw and second derivative spectra, respectively. These findings affirm the validity and significance of the critical region identified by the permutation variable importance measure. The predictive performance of the established models is valid within the range of 7.2 to 29.4 μmol/g of carbonyl content in the training set.
{"title":"Predictive Modeling of Korean Traditional Paper Characteristics Using Machine Learning Approaches (Part 2): Prediction of Carbonyl Content and Analysis of Variable Importance Using Random Forest","authors":"Kang-Jae Kim, Jin-Ho Kim, Geunyong Park, Myung-Joon Jeong","doi":"10.7584/jktappi.2023.10.55.5.13","DOIUrl":"https://doi.org/10.7584/jktappi.2023.10.55.5.13","url":null,"abstract":"This paper introduces a random forest regression model trained with infrared spectral data to predict the carbonyl content of Hanji, a traditional Korean paper. The random forest model demonstrated excellent performance in carbonyl content prediction, surpassing the results obtained from the partial least squares model. To optimize the infrared spectral range for prediction, the spectral range was restricted from the entire range of 4000-400 cm-1 to the narrower range of 1800-1200 cm-1, known for its suitability in characterizing paper properties. This limitation enhanced the coefficients of determination of the model, increasing it from 0.921 to 0.937. A permutation variable importance measure was then applied to identify the key spectral regions contributing to carbonyl content prediction. The analysis pinpointed the 1650-1350 cm-1 range as a crucial region for accurate predictions. Subsequently, a new prediction model was built using data exclusively from this important region, yielding remarkably improved coefficients of determination of 0.960 and 0.965 for the raw and second derivative spectra, respectively. These findings affirm the validity and significance of the critical region identified by the permutation variable importance measure. The predictive performance of the established models is valid within the range of 7.2 to 29.4 μmol/g of carbonyl content in the training set.","PeriodicalId":52548,"journal":{"name":"Palpu Chongi Gisul/Journal of Korea Technical Association of the Pulp and Paper Industry","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136132556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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