Cationized pulp fibers （CPF） were prepared by the adsorption of a novel biodegradable cationic ester quaternary ammonium salt （31441） on bleached softwood kraft pulp fibers. The optimized conditions for the CPF pr...Cationized pulp fibers （CPF） were prepared by the adsorption of a novel biodegradable cationic ester quaternary ammonium salt （31441） on bleached softwood kraft pulp fibers. The optimized conditions for the CPF preparation were： 4% of 31441 （based on oven-dry pulp）, 80℃ and 30 rain. The CPF was characterized by FT-IR, SEM and XPS. Experimental results showed that the CPF improved the retention of precipitated calcium carbonate （PCC） filler significantly. With 0.9% CPF （based on oven-dry pulp）, the retention of PCC increased from 57.53% to 72.21%. The physical properties of paper were also slightly improved. The tensile strength and burst strength of the paper with CPF were higher than those with CPAM. CPF addition had no effect on the stock drainage.展开更多
The flow of pulp fiber suspensions with a consistency below 5% through a pump falls into the turbulent region. The 2-phase 3D turbulent flow of the mixture is simulated in the hydraulic components composed by suction ...The flow of pulp fiber suspensions with a consistency below 5% through a pump falls into the turbulent region. The 2-phase 3D turbulent flow of the mixture is simulated in the hydraulic components composed by suction chamber, front board, semi-impeller and volute casing for the first time. The pseudo-fluid model and the k-ε turbulent model are modified. Phase coupled SIMPLE algorithm is applied to make pressure-velocity correction equation. Based on the results of the numerical simulation, the distribution of velocity, pressure and density of liquid and particle phase are compared and analyzed. The flow analysis in the tip between front board and impeller is emphasized, which reflects the advantage of semi-open impeller when it transports 2-phase medium. This calculation result will be helpful for the design of pump impeller and the establishment of design method of centrifugal stock pump.展开更多
The oxidized bamboo pulp fiber yarns were prepared by the HNO3?/H3PO4-NaNO2 oxidation system. The effects of the oxidation concentration and reaction time on the weight loss, the carboxyl content and the breaking stre...The oxidized bamboo pulp fiber yarns were prepared by the HNO3?/H3PO4-NaNO2 oxidation system. The effects of the oxidation concentration and reaction time on the weight loss, the carboxyl content and the breaking strength of the bamboo pulp fiber yarns were studied and the aggregation structure was investigated by Fourier transform infrared, X-ray and scanning electron microscopy. The results revealed an increase in carboxyl content and a decrease in breaking strength of oxidized bamboo pulp fiber yarns with increasing concentration of oxidant and reaction time. The breaking strength of oxidized bamboo fiber yarns was damaged seriously once the reaction time was more than 120 min or the concentration of oxidant was greater than 1.0%. The crystallinity of bamboo pulp fibers increased slightly under low oxidation degree but decreased with higher oxidation degree.展开更多
The molded pulp,a product of three-dimensional papermaking technology,is environmentally friendly and has a low environmental impact due to its ability to decompose quickly in the natural environment after disposal.Th...The molded pulp,a product of three-dimensional papermaking technology,is environmentally friendly and has a low environmental impact due to its ability to decompose quickly in the natural environment after disposal.The application of molded pulp for food packaging can replace or reduce the use of plastic food packaging.Researchers extract fibers from plants for the production of safe and hygienic molded pulp for food packaging,and they also study and enhance the qualities of molded pulp to broaden its use in the food industry.This paper reviews the sources and varieties of plant fiber used in molded pulp for food packaging,as well as research on the improvement and optimization of the performance of molded pulp products.Additionally,issues with molded pulp’s actual use for food packaging are reviewed,along with the potential for future research.This work can serve as a reference for molded pulp applications and research in the food industry in the future.展开更多
The food packaging industry generally uses papers and paperboards (PPBs) especially for disposable products. According to the Framework Regulation (EC) No. 1935/2004 of the European Union, no transfer of contamination...The food packaging industry generally uses papers and paperboards (PPBs) especially for disposable products. According to the Framework Regulation (EC) No. 1935/2004 of the European Union, no transfer of contamination should occur from food packaging material to the food items. The aim of this study was to determine the presence, numbers, source and different kinds of bacteria present in food packaging PPBs with various contents of pulp fiber. The samples were randomly collected from popular confectioners and fast food restaurants in Saharanpur, India. The results indicated the presence of bacteria in all the samples, ranging from 1.3 × 102 to 6.1 × 103 cfu/g. Most of the samples contained bacteria in more than the permitted concentration of 2.5 × 102 cfu/g as set by Food and Drug Administration (FDA). The detected bacteria were from genera Bacillacea, Staphylococcus and Pseudomonas. According to the FDA declaration, pathogenic bacteria such as B. cereus and S. aureus have been associated with food borne diseases (FBD). Some contaminants in food packaging PPBs were found to be B. subtilis and P. aeroginosa, which produce enzymes like peroxidases and lipoxygenases that are odor generating enzymes.展开更多
In order to investigate the effect of the relative motion of nano CaCO_(3)reinforced bamboo pulp fiber(BPF)/HDPE composite components on the mechanical performance,a comparative study was performed.BPF was treated by ...In order to investigate the effect of the relative motion of nano CaCO_(3)reinforced bamboo pulp fiber(BPF)/HDPE composite components on the mechanical performance,a comparative study was performed.BPF was treated by nano CaCO_(3)blending(BM)and impregnation modification(IM)technology.The composites were produced using hot press(HPMP),extrusion(EMP)and injection molding process(IMP).The physical morphology of BPF was similar at different manufacturing processes.Compared to the samples manufactured by HPMP,a decrease in the(specific)flexural strength of BPF/HDPE composites and an increase in those of composites treated by nano CaCO_(3)manufactured by EMP and IMP were observed.The injection molded composites exhibited the best values in the(specific)impact strength,(specific)tensile properties.IM had a greater effect on the rheological behavior of the composites than BM,and nano CaCO_(3)treatment most effectively affected the performance of the extrusion molded composites.展开更多
A bentonite & PAM particle flocculation system was employed in recycled fiber pulp wastewater treatment in this paper. The optimum conditions of the adsorption & coagulation treatment was explored and optimize...A bentonite & PAM particle flocculation system was employed in recycled fiber pulp wastewater treatment in this paper. The optimum conditions of the adsorption & coagulation treatment was explored and optimized and effects of the treatment were focused on, especially stickies substances removal. Under the optimal conditions, the removal of MTBE extract and cationic demand reached 91.26% and 86.93%, and the average particle size in the treated wastewater pollutants is reduced from 40.95μm to 0.5μm. In this treatment the removal of CODcr, turbidity, SS and color were 89.67%, 99.56%, 95.58% and 93.08%, respectively. The results showed that the particle flocculation system was effective for the treatment of recycled fiber pulp wastewater, especially for controlling the stickies.展开更多
Native corn starch and hydroxypropyl starch (HPS) based plastic films were prepared using the short pulp fiber as reinforcement and the glycerol as the plasticizer. The results of tensile test showed that the tensile ...Native corn starch and hydroxypropyl starch (HPS) based plastic films were prepared using the short pulp fiber as reinforcement and the glycerol as the plasticizer. The results of tensile test showed that the tensile strength and the elongation at break increased with the pulp contents. With the glycerol contents, the elongation at break increased considerably, but the tensile strength decreased. The water uptake of the films decreased with the pulp contents and hydroxypropylation, but increased with the glycerol contents. So it is concluded that the films was reinforced by pulp fiber and hydroxypropylation.展开更多
The fiber morphology and pulping properties of triploid of populus tomentosa from plantation at different ages were investigated in the paper,also the main chemical compositions were determined. The results showed tha...The fiber morphology and pulping properties of triploid of populus tomentosa from plantation at different ages were investigated in the paper,also the main chemical compositions were determined. The results showed that the difference of chemical compositions is not significant, and the extractive contents become bigger in some sort with age, the difference of length weighted mean length of fiber also is not significant, and coarseness of fiber has trend of augment by degree, while the fines content increases obviously with age. That difference of pulping properties between chemical pulping (KP process and Soda-AQ process) and chemimechanical pulping (SCMP process and APMP process) is not significant, which is consistent with the analysis of chemical composition and fiber morphology. Considering comprehensively, the tree age of 5 years is better for paper making industry, also the mixed pulping with different ages of the triploid of populus tomentosa is feasible with steady pulp quality.展开更多
Fiber screen fractionation of recycled old corrugated container(OCC)pulp and subsequent targeted processing of each fraction can lead to higher fiber quality,more uniform pulp,and increased handsheet strength and surf...Fiber screen fractionation of recycled old corrugated container(OCC)pulp and subsequent targeted processing of each fraction can lead to higher fiber quality,more uniform pulp,and increased handsheet strength and surface smoothness.This pilot-scale study evaluates the benefits of fiber fractionation using a pressure screen prior to low consistency(LC)refining.A 0.81-mm smooth holed screen cylinder is utilized,and two refiner plate patterns are adopted(wide 0.99 km/rev BEL and interim 2.01 km/rev BEL).Here,LC-refined reject fractions are mixed with the created microfibrillated cellulose(MFC),and the mixed pulp and paper qualities are compared with no-MFC OCC pulps.The results indicate that the highest tensile strength of the handsheet is obtained by the addition of MFC to the fractionated refined OCC pulp compared to the unfractionated refined OCC and primary OCC pulps at a given specific energy.Furthermore,the experimental approach adopted in this study can be used to optimize recycled OCC pulping systems.Overall,the results indicate that fractionated LC refining plus MFC addition provides higher pulp and paper qualities and the potential for saving energy to reach the desired tensile strength of the OCC pulp.展开更多
基金the Key Scientific and Technological Project of Heilongjiang Province (GB06B501-1)
文摘Cationized pulp fibers （CPF） were prepared by the adsorption of a novel biodegradable cationic ester quaternary ammonium salt （31441） on bleached softwood kraft pulp fibers. The optimized conditions for the CPF preparation were： 4% of 31441 （based on oven-dry pulp）, 80℃ and 30 rain. The CPF was characterized by FT-IR, SEM and XPS. Experimental results showed that the CPF improved the retention of precipitated calcium carbonate （PCC） filler significantly. With 0.9% CPF （based on oven-dry pulp）, the retention of PCC increased from 57.53% to 72.21%. The physical properties of paper were also slightly improved. The tensile strength and burst strength of the paper with CPF were higher than those with CPAM. CPF addition had no effect on the stock drainage.
基金This project is supported by Provincial Natural Science Foundation of Education Department of Jiangsu(No.02kjd470001).
文摘The flow of pulp fiber suspensions with a consistency below 5% through a pump falls into the turbulent region. The 2-phase 3D turbulent flow of the mixture is simulated in the hydraulic components composed by suction chamber, front board, semi-impeller and volute casing for the first time. The pseudo-fluid model and the k-ε turbulent model are modified. Phase coupled SIMPLE algorithm is applied to make pressure-velocity correction equation. Based on the results of the numerical simulation, the distribution of velocity, pressure and density of liquid and particle phase are compared and analyzed. The flow analysis in the tip between front board and impeller is emphasized, which reflects the advantage of semi-open impeller when it transports 2-phase medium. This calculation result will be helpful for the design of pump impeller and the establishment of design method of centrifugal stock pump.
文摘The oxidized bamboo pulp fiber yarns were prepared by the HNO3?/H3PO4-NaNO2 oxidation system. The effects of the oxidation concentration and reaction time on the weight loss, the carboxyl content and the breaking strength of the bamboo pulp fiber yarns were studied and the aggregation structure was investigated by Fourier transform infrared, X-ray and scanning electron microscopy. The results revealed an increase in carboxyl content and a decrease in breaking strength of oxidized bamboo pulp fiber yarns with increasing concentration of oxidant and reaction time. The breaking strength of oxidized bamboo fiber yarns was damaged seriously once the reaction time was more than 120 min or the concentration of oxidant was greater than 1.0%. The crystallinity of bamboo pulp fibers increased slightly under low oxidation degree but decreased with higher oxidation degree.
基金supported by the Special Funds for Fundamental Scientific Research Funds of Central Universities(JUSRP21115)Independent Research Project Funding Project of Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment Technology(FMZ201902).
文摘The molded pulp,a product of three-dimensional papermaking technology,is environmentally friendly and has a low environmental impact due to its ability to decompose quickly in the natural environment after disposal.The application of molded pulp for food packaging can replace or reduce the use of plastic food packaging.Researchers extract fibers from plants for the production of safe and hygienic molded pulp for food packaging,and they also study and enhance the qualities of molded pulp to broaden its use in the food industry.This paper reviews the sources and varieties of plant fiber used in molded pulp for food packaging,as well as research on the improvement and optimization of the performance of molded pulp products.Additionally,issues with molded pulp’s actual use for food packaging are reviewed,along with the potential for future research.This work can serve as a reference for molded pulp applications and research in the food industry in the future.
文摘The food packaging industry generally uses papers and paperboards (PPBs) especially for disposable products. According to the Framework Regulation (EC) No. 1935/2004 of the European Union, no transfer of contamination should occur from food packaging material to the food items. The aim of this study was to determine the presence, numbers, source and different kinds of bacteria present in food packaging PPBs with various contents of pulp fiber. The samples were randomly collected from popular confectioners and fast food restaurants in Saharanpur, India. The results indicated the presence of bacteria in all the samples, ranging from 1.3 × 102 to 6.1 × 103 cfu/g. Most of the samples contained bacteria in more than the permitted concentration of 2.5 × 102 cfu/g as set by Food and Drug Administration (FDA). The detected bacteria were from genera Bacillacea, Staphylococcus and Pseudomonas. According to the FDA declaration, pathogenic bacteria such as B. cereus and S. aureus have been associated with food borne diseases (FBD). Some contaminants in food packaging PPBs were found to be B. subtilis and P. aeroginosa, which produce enzymes like peroxidases and lipoxygenases that are odor generating enzymes.
基金This study is financially supported by the Basic Research Operating Expenses Program of International Centre for Bamboo and Rattan(1632021002).
文摘In order to investigate the effect of the relative motion of nano CaCO_(3)reinforced bamboo pulp fiber(BPF)/HDPE composite components on the mechanical performance,a comparative study was performed.BPF was treated by nano CaCO_(3)blending(BM)and impregnation modification(IM)technology.The composites were produced using hot press(HPMP),extrusion(EMP)and injection molding process(IMP).The physical morphology of BPF was similar at different manufacturing processes.Compared to the samples manufactured by HPMP,a decrease in the(specific)flexural strength of BPF/HDPE composites and an increase in those of composites treated by nano CaCO_(3)manufactured by EMP and IMP were observed.The injection molded composites exhibited the best values in the(specific)impact strength,(specific)tensile properties.IM had a greater effect on the rheological behavior of the composites than BM,and nano CaCO_(3)treatment most effectively affected the performance of the extrusion molded composites.
文摘A bentonite & PAM particle flocculation system was employed in recycled fiber pulp wastewater treatment in this paper. The optimum conditions of the adsorption & coagulation treatment was explored and optimized and effects of the treatment were focused on, especially stickies substances removal. Under the optimal conditions, the removal of MTBE extract and cationic demand reached 91.26% and 86.93%, and the average particle size in the treated wastewater pollutants is reduced from 40.95μm to 0.5μm. In this treatment the removal of CODcr, turbidity, SS and color were 89.67%, 99.56%, 95.58% and 93.08%, respectively. The results showed that the particle flocculation system was effective for the treatment of recycled fiber pulp wastewater, especially for controlling the stickies.
文摘Native corn starch and hydroxypropyl starch (HPS) based plastic films were prepared using the short pulp fiber as reinforcement and the glycerol as the plasticizer. The results of tensile test showed that the tensile strength and the elongation at break increased with the pulp contents. With the glycerol contents, the elongation at break increased considerably, but the tensile strength decreased. The water uptake of the films decreased with the pulp contents and hydroxypropylation, but increased with the glycerol contents. So it is concluded that the films was reinforced by pulp fiber and hydroxypropylation.
文摘The fiber morphology and pulping properties of triploid of populus tomentosa from plantation at different ages were investigated in the paper,also the main chemical compositions were determined. The results showed that the difference of chemical compositions is not significant, and the extractive contents become bigger in some sort with age, the difference of length weighted mean length of fiber also is not significant, and coarseness of fiber has trend of augment by degree, while the fines content increases obviously with age. That difference of pulping properties between chemical pulping (KP process and Soda-AQ process) and chemimechanical pulping (SCMP process and APMP process) is not significant, which is consistent with the analysis of chemical composition and fiber morphology. Considering comprehensively, the tree age of 5 years is better for paper making industry, also the mixed pulping with different ages of the triploid of populus tomentosa is feasible with steady pulp quality.
基金supported by the Beijing Natural Science Foundation(2234090).
文摘Fiber screen fractionation of recycled old corrugated container(OCC)pulp and subsequent targeted processing of each fraction can lead to higher fiber quality,more uniform pulp,and increased handsheet strength and surface smoothness.This pilot-scale study evaluates the benefits of fiber fractionation using a pressure screen prior to low consistency(LC)refining.A 0.81-mm smooth holed screen cylinder is utilized,and two refiner plate patterns are adopted(wide 0.99 km/rev BEL and interim 2.01 km/rev BEL).Here,LC-refined reject fractions are mixed with the created microfibrillated cellulose(MFC),and the mixed pulp and paper qualities are compared with no-MFC OCC pulps.The results indicate that the highest tensile strength of the handsheet is obtained by the addition of MFC to the fractionated refined OCC pulp compared to the unfractionated refined OCC and primary OCC pulps at a given specific energy.Furthermore,the experimental approach adopted in this study can be used to optimize recycled OCC pulping systems.Overall,the results indicate that fractionated LC refining plus MFC addition provides higher pulp and paper qualities and the potential for saving energy to reach the desired tensile strength of the OCC pulp.
