The objective of this study is to improve the mechanical properties and machining performance of high thermal conductivity and low expansion silicon carbide dispersion-strengthened hypereutectic aluminum-silicon elect...The objective of this study is to improve the mechanical properties and machining performance of high thermal conductivity and low expansion silicon carbide dispersion-strengthened hypereutectic aluminum-silicon electronic packaging materials to meet the needs of aviation,aerospace,and electronic packaging fields.We used the powder metallurgy method and high-temperature hot pressing technology to prepare SiC/Al-Si composite materials with different SiC contents(5vol%,10vol%,15vol%,and 20vol%).The results showed that as the SiC content increased,the tensile strength of the composite material first increased and then decreased.The tensile strength was the highest when the SiC content was 15%;the sintering temperature significantly affected the composite material’s structural density and mechanical properties.Findings indicated 700℃was the optimal sintering and the optimal SiC content of SiC/Al-Si composite materials was between 10%and 15%.Besides,the sintering temperature should be strictly controlled to improve the material’s structural density and mechanical properties.展开更多
Based on the deepening awareness of the risk of changing packaging materials of injections,the national regulatory authorities and the China National Pharmaceutical Packaging Association have issued the relevant guide...Based on the deepening awareness of the risk of changing packaging materials of injections,the national regulatory authorities and the China National Pharmaceutical Packaging Association have issued the relevant guidelines and group standards for changing packaging materials in recent years,greatly improving the research and development and technical requirements of packaging materials of injections.In 2021,Guangdong Province carried out the archival examination of the change of listed drugs,among which the proportion of the acceptance of changed injection packaging materials has increased year by year.On the basis of sorting out the archival examination work and combining with the cases of changing packaging materials of chemical injections accepted by Guangdong Province during 2021-2022,the requirements and problems of archival examination were analyzed and discussed to provide a reference and idea for applicants when studying the change in packaging materials.展开更多
Increased environmental and health concerns over the use of plastic packaging or fluorine-containing coatings,in combination with increased market demand for products with a longer shelf life,make bio-based materials ...Increased environmental and health concerns over the use of plastic packaging or fluorine-containing coatings,in combination with increased market demand for products with a longer shelf life,make bio-based materials one of the most important research candidates for alternative paper packaging materials for oil resistance.These bio-based materials have excellent oxygen and oil barriers,which are critical for food packaging.Moreover,they are biodegradable,naturally renewable,and safe.In this artical,two main groups of bio-based oil repellents for paper food packaging,including polysaccharide-based biopolymers and protein-based biopolymers,are enumerated,and the advantages and weaknesses of bio-based oil repellents are discussed,and effective solutions are proposed.Finally,research status and prospects on the development of bio-based oil-resistant coatings for the food packaging industry are presented.展开更多
Thermal property is one of the most important properties of light-emitting diode (LED). Thermal property of LED packaging material determines the heat dissipations of the phosphor and the chip surface, accordingly h...Thermal property is one of the most important properties of light-emitting diode (LED). Thermal property of LED packaging material determines the heat dissipations of the phosphor and the chip surface, accordingly having an influence on the light-emitting efficiency and the life-span of the device. In this paper, photoacoustic piezoelectric (PAPE) technique has been employed to investigate the thermal properties of polyvinyl alcohol (]?VA) and silicon dioxide, which are the new and the traditional packaging materials in white LED, respectively. Firstly, the theory of PAPE technique has been developed for two-layer model in order to investigate soft materials; secondly, the experimental system has been set up and adjusted by measuring the reference sample; thirdly, the thermal diffusivities of PVA and silicon dioxide are measured and analysed. The experimental results show that PVA has a higher thermal diffusivity than silicon dioxide and is a better packaging material in the sense of thermal diffusivity for white LED.展开更多
The polyvinylidene fluoride(PVDF)nanofiber web by electrospinning technology has the characteristics of fast response,high sensitivity,wide range of pressure,etc.,and provides new sensitive materials for the sensor te...The polyvinylidene fluoride(PVDF)nanofiber web by electrospinning technology has the characteristics of fast response,high sensitivity,wide range of pressure,etc.,and provides new sensitive materials for the sensor testing the dynamic pressure such as foot pressure during walking.Because of the nanofiber mesh structure,it must be packaged to collect piezoelectric charge and bear strong mechanical behavior before industrial practice.The PVDF nanofiber web is usually packaged by incorporating a pair of flexible electrode as well as the lead of signal output.This present work will introduce the detailed packaging process and technology of PVDF nanofiber web,and three different types of packaging electrode materials(adhesive copper foil tape,indium tin oxide(ITO)thin plate,and adhesive conductive cloth)in previously published literatures are compared by the piezoelectric response of their sensor prototypes to a periodic mechanical activation.The results showed that the surface property of packaging material had a significant effect on the piezoelectric response of sensor by PVDF nanofiber web.For PVDF nanofiber web sensor,therefore,it needed a deep investigation on the specific packaging technology in terms of different working conditions.展开更多
Paper packaging materials like cardboards are widely used to protect archives which are a major kind of cultural relics.Unfortunately,paper is a combustible material,and thus exploring environment-friendly flame retar...Paper packaging materials like cardboards are widely used to protect archives which are a major kind of cultural relics.Unfortunately,paper is a combustible material,and thus exploring environment-friendly flame retardant for paper-based archive packaging material plays an important role.Herein,boric acid,borax and disodium octaborate are used to modify the craft paper-based packaging materials for archive conservation to improve fire safety.The modified craft paper exhibits much higher flame retardancy than the pristine one dose based on vertical burning tests,without much influence on mechanical properties such as tensile strength and elongation at break.Thermogravimetric analysis(TGA),scanning electron microscope(SEM),and X-ray photoelectron spectroscopy(XPS)reveal that porous glass structure is formed during the combustion,because thermal decomposition of boric acid,borax and disodium octaborate will produce porous glassy matter as B_(2)O_(3).The porous glass covers the paper surface as an insulating layer which retards the further pyrolysis and combustion,resulting in a denser carbon layer.Our study provides a robust way to reduce the fire hazard of the archive packaging material by applying environment-friendly boron-based fire retardants.展开更多
Paper products such as corrugated paperboards are the most common green packaging materials, which are renewable, sustainable, recyclable and biodegradable. However, the plastic or metal straps used to secure the cart...Paper products such as corrugated paperboards are the most common green packaging materials, which are renewable, sustainable, recyclable and biodegradable. However, the plastic or metal straps used to secure the carton boxes are not so green. At the end of packaging, the carton boxes can be recycled, but the plastic/metal straps have to be sorted out for disposal separately. This review focuses on: 1) the global trend of green packaging;2) conventional plastic/metal strapping materials for carton boxes;3) conventional market pulp baling with steel wire as the tying materials;4) cellulose fiber-based materials for strapping market pulp bales and carton boxes. New generation of cellulose paper straps are being developed for more challenging applications with superior strength properties and repulpability.展开更多
In this study,the effect of hot calendering process on the microstructure and properties of poly(p-phenylene terephthalamide)(PPTA) paper-based materials was investigated.The microstructures of the fracture surface,cr...In this study,the effect of hot calendering process on the microstructure and properties of poly(p-phenylene terephthalamide)(PPTA) paper-based materials was investigated.The microstructures of the fracture surface,crystalline structure,and single fiber strength of the PPTA paperbased materials as well as the different bonding behaviors between the PPTA fibers and PPTA fibrids obtained before and after the hot calendering process were examined.The results indicated that a high linear pressure would result in a limited improvement of the strength owing to the unimproved paper structure.The optimal values of tensile index and dielectric strength of 56.6 N·m/g and 27.6 kV/mm,respectively,could only be achieved with a synergistic effects of hot calendering temperature and linear pressure(240℃ and 110 k N/m,respectively).This result suggested it was possible to achieve a significant reinforcement and improvement in the interfacial bonding of functional PPTA paper-based materials,and avoid the formation of unexpected pleats and cracks in PPTA paper-based materials during the hot calendering process.展开更多
A polymer-based carbon nano-tubes (CNTs) composite with high electromagnetic (EM) wave shielding effectiveness (SE) and with high mechanical property is developed for packaging of electronic modulus or devices.The ...A polymer-based carbon nano-tubes (CNTs) composite with high electromagnetic (EM) wave shielding effectiveness (SE) and with high mechanical property is developed for packaging of electronic modulus or devices.The liquid crystal polymers (LCP) and melamine formaldehydes (MF) polymer are used to study the orientation effect of CNTs in various polymeric matrix.The influences of orientation,aspect ratio,and mass fraction of CNTs upon the shielding effectiveness (SE) of CNTs-composites are investigated.The higher the orientation,aspect ratio,and weight percentages of nano-materials are, the higher the SE of the carbon composites.The highest SE for the CNTs/LCP nano composite obtained is more than 62 dB. This results may lead to the developing for CPU IC chip packaging.展开更多
Plastic and polymer additives (PA) have unique rational advantages for various water and food packaging applications. However, their (bio)chemical natures are recently recognized for their negative human health impact...Plastic and polymer additives (PA) have unique rational advantages for various water and food packaging applications. However, their (bio)chemical natures are recently recognized for their negative human health impacts. The major adverse consequence of these additives in consumer products is in the form of endocrine-disruption related health-downgrades. Such findings still remain underappreciated in most parts globally;part of which could be ascribed to fragmented studies towards better understanding on the occurrence, release and migration, human exposure, epidemiology and risk assessment of PA from packaging materials. In addition there is limited and disconnected dissemination of research findings on PA effects and mitigation measures to society at present. In light of appropriateness of this topic, a trans-disciplinary research agenda is required for addressing exposure routes to PA, human health burden and prevention measures. This perspective article discusses important research questions relating to PA, which try to shed light to a grey scientific area and help increase consumers’ awareness and intervention to such exposures.展开更多
Three different packaging materials of (37 cm × 25 cm) size (Sealed Transparent Polythene Bag (STPB) Sealed Paper Bag (SPB) (Brown envelope), Open Mouth Polythene Bag (OMPB) (Black incolour)) were used for Oreoch...Three different packaging materials of (37 cm × 25 cm) size (Sealed Transparent Polythene Bag (STPB) Sealed Paper Bag (SPB) (Brown envelope), Open Mouth Polythene Bag (OMPB) (Black incolour)) were used for Oreochromisniloticus (O), Clariasgariepinus (C) and Mormyrusrume (M). Twenty fish samples per species (averaging 250 gm) were hot smoked dried whole for 36 hours at an average temperature of 100?C. Packaged hot at the rate of 6 fishes per package for each species (three packs for each packaging treatment i.e. 18 pieces were packed while the remaining 2 pieces were used for initial bacteria load and microbial load). Microbial load (Total Viable Count (TVC), Total Coliform Count (TCC) and Total Fungi Count (TFC)) for the fresh fish was initial hot smoked and finally at the end of 12 weeks was monitored. The TVC (bacterial load) of O. niloticus dropped from (10.6 - 8.4) × 104 (fresh state-hot smoked) and M. rume (9.8 - 7.0) × 104, while C. gariepinus slightly increased from (12.4 - 12.6) × 104. After hot smoking, highest TVC of 8.6 × 104 (OMPBC), 8.3 × 104 (SPBC) and 8.2 × 104 (STPBC) were recorded in C. gariepinus among the 9 packag- ing at 12 weeks. However highest tendency for heavy TVC is in all OMPB with highest bacteria load in the OMPBC (8.6 × 104), 7.6 × 104 (OMPBO) and 6.6 × 104 (OMPBM). After 12 weeks highest ranged TFC of (0.6 - 0.7) × 104 was recorded in M. rume as against 0.2 × 104 recorded in the initial smoked for all. TCC was highest in C. gariepinus (4.0 - 4.3) × 104. Packaging did not limit the existence of micro-organisms. Six bacteria species (Micrococcus (acidiophilus, luteus), Bacillus (subtilis, cereus, aureus), Staphylococcus aureus, Streptococcus lactis, Proteus (vulgaricus, morganii), Pseudomonas aureginosa) and three fungi species (Aspergillus (niger, tamari), Rhizopusnigricans, fusariumoxysporum) were represented in all the packages. On the average five bacteria and two fungi species were represented, excepting for OMPBM and OMPBO with six bacteria species.展开更多
The improved"Snow Bud"packaging mainly includes the medium packing and the external packaging,with the cuboid as the main structure,and the paper as the main material.The inner packaging uses the tin foil pa...The improved"Snow Bud"packaging mainly includes the medium packing and the external packaging,with the cuboid as the main structure,and the paper as the main material.The inner packaging uses the tin foil paper bag.Because of the thin thickness of the carton used and the problems in colors,patterns,character design,structures and other aspects,the purpose of the improvement is to use the new structures to enhance the practical functions of the packaging and to explore the application of the new materials in the tea packaging.展开更多
The rapid development of the electronic information industry brings to the irreplaceable role of electronic components, therefore the search of a more reliable packaging material has become increasingly important. In ...The rapid development of the electronic information industry brings to the irreplaceable role of electronic components, therefore the search of a more reliable packaging material has become increasingly important. In the electronic packaging system, the failure phenomenon caused by residual stress is one of the key factors restricting the development of electronic packaging technology. In order to use the in-situ characterization technology to explore the residual stress inducing mechanism and failure mechanism of epoxy-based advanced packaging materials, this paper gives a review of related previous research, and lays a theoretical foundation for the upcoming research. The classification and generation mechanism of residual stress are clarified in this paper, which provides data support for future related research.展开更多
Light emitting diodes(LEDs)have accounted for most of the lighting market as the technology matures and costs continue to reduce.As a new type of e-waste,LED is a double-edged sword,as it contains not only precious an...Light emitting diodes(LEDs)have accounted for most of the lighting market as the technology matures and costs continue to reduce.As a new type of e-waste,LED is a double-edged sword,as it contains not only precious and rare metals but also organic packaging materials.In previous studies,LED recycling focused on recovering precious and strategic metals while ignoring harmful substances such as organic packaging materials.Unlike crushing and other traditional methods,hydrothermal treatment can provide an environment-friendly process for decomposing packaging materials.This work developed a closed reaction vessel,where the degradation rate of plastic polyphthalamide(PPA)was close to 100%,with nano-TiO_(2)encapsulated in plastic PPA being efficiently recovered,while metals contained in LED were also recycled efficiently.Besides,the role of water in plastic PPA degradation that has been overlooked in current studies was explored and speculated in detail in this work.Environmental impact assessment revealed that the proposed recycling route for waste LED could significantly reduce the overall environmental impact compared to the currently published processes.Especially the developed method could reduce more than half the impact of global warming.Furthermore,this research provides a theoretical basis and a promising method for recycling other plastic-packaged e-waste devices,such as integrated circuits.展开更多
The compositions, structures and properties of envi- ronmental-friendly ramming materials for mud package and taphole of large-scaled blast furnaces were studied. The results show that the formation of silica fibers m...The compositions, structures and properties of envi- ronmental-friendly ramming materials for mud package and taphole of large-scaled blast furnaces were studied. The results show that the formation of silica fibers makes structure of ramming materials dense. During the process of extruding mud and ramming materials, SiC is partly oxidized ; CaO , F% 03 and carbon penetrate towards the outer wall. The improvement of ramming materials can inhibit the penetration of molten slag, iron and carbon. The bulk density of environmental-friendly ramming ma- terials dried at 200 ℃ is 2.90 g · cm-3, the cold com- pressive strength of this kind of ramming materials dried at 200 ℃ is about 17. 0 MPa and fired at I 450 ℃ is about 39. 2 MPa.展开更多
This study was conducted to investigate the effects of different packaging methods on seed germination and vigor under a long-term bank storage condition, selecting suitable packaging materials and methods, and compre...This study was conducted to investigate the effects of different packaging methods on seed germination and vigor under a long-term bank storage condition, selecting suitable packaging materials and methods, and comprehensively estimate changes in seed vigor of seeds stored with different packaging materials. Hibiscus cannabinus L. seeds were stored in aluminium box, seed box, glass bottle, POlyethylene film bag, sack and kraft paper bag as packaging materials in a, long-term bank and tested for their seeds germinability, electrical conductivity and field seedling rate after 31 years. The results showed that the kenaf seeds with an initial germination rate of 88% exhibited the germination rates over 79.7% after being stored in the 6 packaging materials for 31 years, the germination rates of seeds packaged with paper bag and sack and of those sealed in film bag and aluminium box showed significantly decreased germination rates, while the seeds sealed in seed boxes and glass bottles exhibited non-significant decreases in seed germination rate, and their germination rates were still above 85%. Seed box and glass bottle were the packaging materials most suitable for long-term safe storage of kenaf seeds with a safe storage period long than 31 years.展开更多
The Cu/Invar composites of 40% Cu were prepared by powder metallurgy, and the composites were rolled with 70% reduction and subsequently annealed at 750 ℃. Phases, microstructures and properties of the composites wer...The Cu/Invar composites of 40% Cu were prepared by powder metallurgy, and the composites were rolled with 70% reduction and subsequently annealed at 750 ℃. Phases, microstructures and properties of the composites were then studied. After that, the amount of a-Fe(Ni,Co) in the composites is reduced, because a-Fe(Ni,Co) partly transfers into y-Fe(Ni,Co) through the diffusion of the Ni atoms into a-Fe(Ni,Co) from Cu. When the rolling reduction is less than 40%, the deformation of Cu takes place, resulting in the movement of the Invar particles and the seaming of the pores. When the rolling reduction is in the range from 40% to 60%, the deformations of Invar and Cu occur simultaneously to form a streamline structure. After rolling till 70% and subsequent annealing, the Cu/Invar composites have fine comprehensive properties with a relative density of 98.6%, a tensile strength of 360 MPa, an elongation rate of 50%, a thermal conductivity of 25.42 W/(m.K) (as-tested) and a CTE of 10.79× 10-6/K (20-100 ℃).展开更多
Diamond/Cu-xCr composites were fabricated by pressure infiltration process.The thermal conductivities of diamond/Cu-xCr(x = 0.1,0.5,0.8) composites were above 650 W/mK,higher than that of diamond/Cu composites.The t...Diamond/Cu-xCr composites were fabricated by pressure infiltration process.The thermal conductivities of diamond/Cu-xCr(x = 0.1,0.5,0.8) composites were above 650 W/mK,higher than that of diamond/Cu composites.The tensile strengths ranged from 186 to 225 MPa,and the bonding strengths ranged from 400 to 525 MPa.Influences of Cr element on the thermo-physical properties and interface structures were analyzed.The intermediate layer was confirmed as Cr3C2 and the amount of Cr3C2 increased with the increase of Cr concentration in Cu-xCr alloys.When the Cr concentration was up to 0.5 wt.%,the content of the Cr3C2 layer was constant.As the thickness of the Cr3C2 layer became larger,the composites showed a lower thermal conductivity but higher mechanical properties.The coefficients of thermal expansion(CTE) of diamond/Cu-xCr(x = 0.1,0.5,0.8) composites were in good agreement with the predictions of the Kerner' model.展开更多
The current work explores the potential use of commercial Chinese bayberry tannin(BT)to develop antioxidant PVA-based films using solvent casting process for packaging applications.The effect of BT concentration on op...The current work explores the potential use of commercial Chinese bayberry tannin(BT)to develop antioxidant PVA-based films using solvent casting process for packaging applications.The effect of BT concentration on opa-city,water resistance and antioxidant capacity of resulting films was investigated.Properties like tensile strength,thermal behavior,and morphological aspects were also characterized.The experimental results showed that PVA/BT films formed with uniformly brown color and generally good transparency,offering good antioxidant ability.The PVA film containing BT presented slightly higher water resistance according to the results of moisture content and water vapor permeability,especially at low BT content(<10 wt%).The PVA can be compounded with up to 10 wt%BT without any obvious deterioration in the tensile strength.The PVA/BT films exhibited better thermal degradation behavior compared with PVA alone because of the chemical bonds of PVA-BT and the for-mation of char at high temperature.Based on the results,PVA incorporated with Chinese bayberry tannin may provide broader formulation options for packaging materials with antioxidant action.展开更多
文摘The objective of this study is to improve the mechanical properties and machining performance of high thermal conductivity and low expansion silicon carbide dispersion-strengthened hypereutectic aluminum-silicon electronic packaging materials to meet the needs of aviation,aerospace,and electronic packaging fields.We used the powder metallurgy method and high-temperature hot pressing technology to prepare SiC/Al-Si composite materials with different SiC contents(5vol%,10vol%,15vol%,and 20vol%).The results showed that as the SiC content increased,the tensile strength of the composite material first increased and then decreased.The tensile strength was the highest when the SiC content was 15%;the sintering temperature significantly affected the composite material’s structural density and mechanical properties.Findings indicated 700℃was the optimal sintering and the optimal SiC content of SiC/Al-Si composite materials was between 10%and 15%.Besides,the sintering temperature should be strictly controlled to improve the material’s structural density and mechanical properties.
基金Supported by the Research on the Archival Examination Strategy of changes in Listed Drugs Based on Risk under the Guidance of Holders'Principal Responsibility(2023TDZ01)。
文摘Based on the deepening awareness of the risk of changing packaging materials of injections,the national regulatory authorities and the China National Pharmaceutical Packaging Association have issued the relevant guidelines and group standards for changing packaging materials in recent years,greatly improving the research and development and technical requirements of packaging materials of injections.In 2021,Guangdong Province carried out the archival examination of the change of listed drugs,among which the proportion of the acceptance of changed injection packaging materials has increased year by year.On the basis of sorting out the archival examination work and combining with the cases of changing packaging materials of chemical injections accepted by Guangdong Province during 2021-2022,the requirements and problems of archival examination were analyzed and discussed to provide a reference and idea for applicants when studying the change in packaging materials.
文摘Increased environmental and health concerns over the use of plastic packaging or fluorine-containing coatings,in combination with increased market demand for products with a longer shelf life,make bio-based materials one of the most important research candidates for alternative paper packaging materials for oil resistance.These bio-based materials have excellent oxygen and oil barriers,which are critical for food packaging.Moreover,they are biodegradable,naturally renewable,and safe.In this artical,two main groups of bio-based oil repellents for paper food packaging,including polysaccharide-based biopolymers and protein-based biopolymers,are enumerated,and the advantages and weaknesses of bio-based oil repellents are discussed,and effective solutions are proposed.Finally,research status and prospects on the development of bio-based oil-resistant coatings for the food packaging industry are presented.
基金Project supported by the National Nature Science Foundation of China (Grant No. 50506006)the National High Technology Research and Development Program of China (Grant No. 2006AA03A116)the Youth Foundation of University of Electronic Science and Technology of China (Grant No. JX05024)
文摘Thermal property is one of the most important properties of light-emitting diode (LED). Thermal property of LED packaging material determines the heat dissipations of the phosphor and the chip surface, accordingly having an influence on the light-emitting efficiency and the life-span of the device. In this paper, photoacoustic piezoelectric (PAPE) technique has been employed to investigate the thermal properties of polyvinyl alcohol (]?VA) and silicon dioxide, which are the new and the traditional packaging materials in white LED, respectively. Firstly, the theory of PAPE technique has been developed for two-layer model in order to investigate soft materials; secondly, the experimental system has been set up and adjusted by measuring the reference sample; thirdly, the thermal diffusivities of PVA and silicon dioxide are measured and analysed. The experimental results show that PVA has a higher thermal diffusivity than silicon dioxide and is a better packaging material in the sense of thermal diffusivity for white LED.
基金“111 Project”Biomedical Textile Materials Science and Technology,China(No.B07024)National Natural Science Foundation of China(No.51405079)+2 种基金China Postdoctoral Science Foundation(No.2015M570307)the Fundamental Research Funds for the Central Universities,Chinathe Jiangsu Planned Projects for Postdoctoral Research Funds,China
文摘The polyvinylidene fluoride(PVDF)nanofiber web by electrospinning technology has the characteristics of fast response,high sensitivity,wide range of pressure,etc.,and provides new sensitive materials for the sensor testing the dynamic pressure such as foot pressure during walking.Because of the nanofiber mesh structure,it must be packaged to collect piezoelectric charge and bear strong mechanical behavior before industrial practice.The PVDF nanofiber web is usually packaged by incorporating a pair of flexible electrode as well as the lead of signal output.This present work will introduce the detailed packaging process and technology of PVDF nanofiber web,and three different types of packaging electrode materials(adhesive copper foil tape,indium tin oxide(ITO)thin plate,and adhesive conductive cloth)in previously published literatures are compared by the piezoelectric response of their sensor prototypes to a periodic mechanical activation.The results showed that the surface property of packaging material had a significant effect on the piezoelectric response of sensor by PVDF nanofiber web.For PVDF nanofiber web sensor,therefore,it needed a deep investigation on the specific packaging technology in terms of different working conditions.
文摘Paper packaging materials like cardboards are widely used to protect archives which are a major kind of cultural relics.Unfortunately,paper is a combustible material,and thus exploring environment-friendly flame retardant for paper-based archive packaging material plays an important role.Herein,boric acid,borax and disodium octaborate are used to modify the craft paper-based packaging materials for archive conservation to improve fire safety.The modified craft paper exhibits much higher flame retardancy than the pristine one dose based on vertical burning tests,without much influence on mechanical properties such as tensile strength and elongation at break.Thermogravimetric analysis(TGA),scanning electron microscope(SEM),and X-ray photoelectron spectroscopy(XPS)reveal that porous glass structure is formed during the combustion,because thermal decomposition of boric acid,borax and disodium octaborate will produce porous glassy matter as B_(2)O_(3).The porous glass covers the paper surface as an insulating layer which retards the further pyrolysis and combustion,resulting in a denser carbon layer.Our study provides a robust way to reduce the fire hazard of the archive packaging material by applying environment-friendly boron-based fire retardants.
文摘Paper products such as corrugated paperboards are the most common green packaging materials, which are renewable, sustainable, recyclable and biodegradable. However, the plastic or metal straps used to secure the carton boxes are not so green. At the end of packaging, the carton boxes can be recycled, but the plastic/metal straps have to be sorted out for disposal separately. This review focuses on: 1) the global trend of green packaging;2) conventional plastic/metal strapping materials for carton boxes;3) conventional market pulp baling with steel wire as the tying materials;4) cellulose fiber-based materials for strapping market pulp bales and carton boxes. New generation of cellulose paper straps are being developed for more challenging applications with superior strength properties and repulpability.
基金the financial support to this research from the open fund of state key laboratory for modification of chemical fibers and polymer materials (LK1601)projects of education department of Shaanxi provincial government (15JF012)National Natural Science Foundation of China (51402180)
文摘In this study,the effect of hot calendering process on the microstructure and properties of poly(p-phenylene terephthalamide)(PPTA) paper-based materials was investigated.The microstructures of the fracture surface,crystalline structure,and single fiber strength of the PPTA paperbased materials as well as the different bonding behaviors between the PPTA fibers and PPTA fibrids obtained before and after the hot calendering process were examined.The results indicated that a high linear pressure would result in a limited improvement of the strength owing to the unimproved paper structure.The optimal values of tensile index and dielectric strength of 56.6 N·m/g and 27.6 kV/mm,respectively,could only be achieved with a synergistic effects of hot calendering temperature and linear pressure(240℃ and 110 k N/m,respectively).This result suggested it was possible to achieve a significant reinforcement and improvement in the interfacial bonding of functional PPTA paper-based materials,and avoid the formation of unexpected pleats and cracks in PPTA paper-based materials during the hot calendering process.
文摘A polymer-based carbon nano-tubes (CNTs) composite with high electromagnetic (EM) wave shielding effectiveness (SE) and with high mechanical property is developed for packaging of electronic modulus or devices.The liquid crystal polymers (LCP) and melamine formaldehydes (MF) polymer are used to study the orientation effect of CNTs in various polymeric matrix.The influences of orientation,aspect ratio,and mass fraction of CNTs upon the shielding effectiveness (SE) of CNTs-composites are investigated.The higher the orientation,aspect ratio,and weight percentages of nano-materials are, the higher the SE of the carbon composites.The highest SE for the CNTs/LCP nano composite obtained is more than 62 dB. This results may lead to the developing for CPU IC chip packaging.
文摘Plastic and polymer additives (PA) have unique rational advantages for various water and food packaging applications. However, their (bio)chemical natures are recently recognized for their negative human health impacts. The major adverse consequence of these additives in consumer products is in the form of endocrine-disruption related health-downgrades. Such findings still remain underappreciated in most parts globally;part of which could be ascribed to fragmented studies towards better understanding on the occurrence, release and migration, human exposure, epidemiology and risk assessment of PA from packaging materials. In addition there is limited and disconnected dissemination of research findings on PA effects and mitigation measures to society at present. In light of appropriateness of this topic, a trans-disciplinary research agenda is required for addressing exposure routes to PA, human health burden and prevention measures. This perspective article discusses important research questions relating to PA, which try to shed light to a grey scientific area and help increase consumers’ awareness and intervention to such exposures.
文摘Three different packaging materials of (37 cm × 25 cm) size (Sealed Transparent Polythene Bag (STPB) Sealed Paper Bag (SPB) (Brown envelope), Open Mouth Polythene Bag (OMPB) (Black incolour)) were used for Oreochromisniloticus (O), Clariasgariepinus (C) and Mormyrusrume (M). Twenty fish samples per species (averaging 250 gm) were hot smoked dried whole for 36 hours at an average temperature of 100?C. Packaged hot at the rate of 6 fishes per package for each species (three packs for each packaging treatment i.e. 18 pieces were packed while the remaining 2 pieces were used for initial bacteria load and microbial load). Microbial load (Total Viable Count (TVC), Total Coliform Count (TCC) and Total Fungi Count (TFC)) for the fresh fish was initial hot smoked and finally at the end of 12 weeks was monitored. The TVC (bacterial load) of O. niloticus dropped from (10.6 - 8.4) × 104 (fresh state-hot smoked) and M. rume (9.8 - 7.0) × 104, while C. gariepinus slightly increased from (12.4 - 12.6) × 104. After hot smoking, highest TVC of 8.6 × 104 (OMPBC), 8.3 × 104 (SPBC) and 8.2 × 104 (STPBC) were recorded in C. gariepinus among the 9 packag- ing at 12 weeks. However highest tendency for heavy TVC is in all OMPB with highest bacteria load in the OMPBC (8.6 × 104), 7.6 × 104 (OMPBO) and 6.6 × 104 (OMPBM). After 12 weeks highest ranged TFC of (0.6 - 0.7) × 104 was recorded in M. rume as against 0.2 × 104 recorded in the initial smoked for all. TCC was highest in C. gariepinus (4.0 - 4.3) × 104. Packaging did not limit the existence of micro-organisms. Six bacteria species (Micrococcus (acidiophilus, luteus), Bacillus (subtilis, cereus, aureus), Staphylococcus aureus, Streptococcus lactis, Proteus (vulgaricus, morganii), Pseudomonas aureginosa) and three fungi species (Aspergillus (niger, tamari), Rhizopusnigricans, fusariumoxysporum) were represented in all the packages. On the average five bacteria and two fungi species were represented, excepting for OMPBM and OMPBO with six bacteria species.
文摘The improved"Snow Bud"packaging mainly includes the medium packing and the external packaging,with the cuboid as the main structure,and the paper as the main material.The inner packaging uses the tin foil paper bag.Because of the thin thickness of the carton used and the problems in colors,patterns,character design,structures and other aspects,the purpose of the improvement is to use the new structures to enhance the practical functions of the packaging and to explore the application of the new materials in the tea packaging.
文摘The rapid development of the electronic information industry brings to the irreplaceable role of electronic components, therefore the search of a more reliable packaging material has become increasingly important. In the electronic packaging system, the failure phenomenon caused by residual stress is one of the key factors restricting the development of electronic packaging technology. In order to use the in-situ characterization technology to explore the residual stress inducing mechanism and failure mechanism of epoxy-based advanced packaging materials, this paper gives a review of related previous research, and lays a theoretical foundation for the upcoming research. The classification and generation mechanism of residual stress are clarified in this paper, which provides data support for future related research.
基金supported by the National Natural Science Foundation of China(52270132).
文摘Light emitting diodes(LEDs)have accounted for most of the lighting market as the technology matures and costs continue to reduce.As a new type of e-waste,LED is a double-edged sword,as it contains not only precious and rare metals but also organic packaging materials.In previous studies,LED recycling focused on recovering precious and strategic metals while ignoring harmful substances such as organic packaging materials.Unlike crushing and other traditional methods,hydrothermal treatment can provide an environment-friendly process for decomposing packaging materials.This work developed a closed reaction vessel,where the degradation rate of plastic polyphthalamide(PPA)was close to 100%,with nano-TiO_(2)encapsulated in plastic PPA being efficiently recovered,while metals contained in LED were also recycled efficiently.Besides,the role of water in plastic PPA degradation that has been overlooked in current studies was explored and speculated in detail in this work.Environmental impact assessment revealed that the proposed recycling route for waste LED could significantly reduce the overall environmental impact compared to the currently published processes.Especially the developed method could reduce more than half the impact of global warming.Furthermore,this research provides a theoretical basis and a promising method for recycling other plastic-packaged e-waste devices,such as integrated circuits.
文摘The compositions, structures and properties of envi- ronmental-friendly ramming materials for mud package and taphole of large-scaled blast furnaces were studied. The results show that the formation of silica fibers makes structure of ramming materials dense. During the process of extruding mud and ramming materials, SiC is partly oxidized ; CaO , F% 03 and carbon penetrate towards the outer wall. The improvement of ramming materials can inhibit the penetration of molten slag, iron and carbon. The bulk density of environmental-friendly ramming ma- terials dried at 200 ℃ is 2.90 g · cm-3, the cold com- pressive strength of this kind of ramming materials dried at 200 ℃ is about 17. 0 MPa and fired at I 450 ℃ is about 39. 2 MPa.
文摘This study was conducted to investigate the effects of different packaging methods on seed germination and vigor under a long-term bank storage condition, selecting suitable packaging materials and methods, and comprehensively estimate changes in seed vigor of seeds stored with different packaging materials. Hibiscus cannabinus L. seeds were stored in aluminium box, seed box, glass bottle, POlyethylene film bag, sack and kraft paper bag as packaging materials in a, long-term bank and tested for their seeds germinability, electrical conductivity and field seedling rate after 31 years. The results showed that the kenaf seeds with an initial germination rate of 88% exhibited the germination rates over 79.7% after being stored in the 6 packaging materials for 31 years, the germination rates of seeds packaged with paper bag and sack and of those sealed in film bag and aluminium box showed significantly decreased germination rates, while the seeds sealed in seed boxes and glass bottles exhibited non-significant decreases in seed germination rate, and their germination rates were still above 85%. Seed box and glass bottle were the packaging materials most suitable for long-term safe storage of kenaf seeds with a safe storage period long than 31 years.
文摘The Cu/Invar composites of 40% Cu were prepared by powder metallurgy, and the composites were rolled with 70% reduction and subsequently annealed at 750 ℃. Phases, microstructures and properties of the composites were then studied. After that, the amount of a-Fe(Ni,Co) in the composites is reduced, because a-Fe(Ni,Co) partly transfers into y-Fe(Ni,Co) through the diffusion of the Ni atoms into a-Fe(Ni,Co) from Cu. When the rolling reduction is less than 40%, the deformation of Cu takes place, resulting in the movement of the Invar particles and the seaming of the pores. When the rolling reduction is in the range from 40% to 60%, the deformations of Invar and Cu occur simultaneously to form a streamline structure. After rolling till 70% and subsequent annealing, the Cu/Invar composites have fine comprehensive properties with a relative density of 98.6%, a tensile strength of 360 MPa, an elongation rate of 50%, a thermal conductivity of 25.42 W/(m.K) (as-tested) and a CTE of 10.79× 10-6/K (20-100 ℃).
基金supported by the High-Tech Research and Development Program of China (Nos.2006AA03A135 and 2008AA03Z505)
文摘Diamond/Cu-xCr composites were fabricated by pressure infiltration process.The thermal conductivities of diamond/Cu-xCr(x = 0.1,0.5,0.8) composites were above 650 W/mK,higher than that of diamond/Cu composites.The tensile strengths ranged from 186 to 225 MPa,and the bonding strengths ranged from 400 to 525 MPa.Influences of Cr element on the thermo-physical properties and interface structures were analyzed.The intermediate layer was confirmed as Cr3C2 and the amount of Cr3C2 increased with the increase of Cr concentration in Cu-xCr alloys.When the Cr concentration was up to 0.5 wt.%,the content of the Cr3C2 layer was constant.As the thickness of the Cr3C2 layer became larger,the composites showed a lower thermal conductivity but higher mechanical properties.The coefficients of thermal expansion(CTE) of diamond/Cu-xCr(x = 0.1,0.5,0.8) composites were in good agreement with the predictions of the Kerner' model.
基金This work was supported by the National Natural Science Foundation of China(NSFC 31971595,31760187)the Program for Leading Talents of Science and Technology(Grant No.2017HA013)the Yunnan Provincial Reserve Talents for Middle&Young Academic and Technical Leaders(2019HB026),and the 111 Project.
文摘The current work explores the potential use of commercial Chinese bayberry tannin(BT)to develop antioxidant PVA-based films using solvent casting process for packaging applications.The effect of BT concentration on opa-city,water resistance and antioxidant capacity of resulting films was investigated.Properties like tensile strength,thermal behavior,and morphological aspects were also characterized.The experimental results showed that PVA/BT films formed with uniformly brown color and generally good transparency,offering good antioxidant ability.The PVA film containing BT presented slightly higher water resistance according to the results of moisture content and water vapor permeability,especially at low BT content(<10 wt%).The PVA can be compounded with up to 10 wt%BT without any obvious deterioration in the tensile strength.The PVA/BT films exhibited better thermal degradation behavior compared with PVA alone because of the chemical bonds of PVA-BT and the for-mation of char at high temperature.Based on the results,PVA incorporated with Chinese bayberry tannin may provide broader formulation options for packaging materials with antioxidant action.