蜂窝纸板在空投包装中的应用

目的研究蜂窝纸板在空投包装中的应用,构建军品绿色包装。方法通过研究蜂窝纸板的性能,并与瓦楞纸板进行比较,来分析蜂窝纸板在空投包装领域的应用效果及前景。结果蜂窝纸板密度小、抗弯刚度大、平压强度高、侧压强度高、缓冲性能好,是低碳可再生的绿色包装材料,可应用于空投平台、无伞空投物资、特殊包装等方面。结论蜂窝纸板可作为空投包装材料。     

易碎文物包装用新型囊匣的设计与防护性能研究

采用瓦楞纸板代替传统囊匣用硬纸板,分别制作了瓦楞硬囊匣和瓦楞软硬囊匣等瓦楞纸板新型囊匣包装系统,并以振动传递率、产品磨损率、跌落冲击平均加速度为指标,全面评估了新型囊匣包装系统和传统灰纸板囊匣包装系统(灰纸板硬囊匣、灰纸板软硬囊匣和灰纸板软囊匣)的性能。结果标明,新型瓦楞纸板囊匣的缓冲防震性能和抗磨损性能明显优于传统灰纸板囊匣。     

泡沫填充型蜂窝纸板面外压缩性能实验研究EI北大核心CSCD

对泡沫填充型蜂窝纸板的面外压缩性能及其影响规律进行了试验研究。将不同密度的聚氨酯泡沫以不同填充方式填充入不同边长的蜂窝胞元中,以不同的压缩速率对上述泡沫填充型蜂窝纸板进行准静态压缩试验,结果发现:蜂窝胞元边长显著影响泡沫填充型蜂窝纸板的面外压缩性能,初始峰值应力和平台应力均随着胞元边长的增大而减小;当使用低密度(高发泡倍率)的泡沫填充蜂窝纸板时,初始峰值应力和平台应力均优于高密度(低发泡倍率)泡沫填充型蜂窝纸板;部分填充和完全填充的泡沫填充型蜂窝纸板相对于未填充的蜂窝纸板的平台应力和吸能性能均有大幅提升,不但降低了初始峰值应力,还提高了平台应力,对面外压缩性能和缓冲性能改善明显;在2 mm/min^50 mm/min的压缩速率区间内,泡沫填充型蜂窝纸板面外压缩性能受压缩速率的影响不显著。本文的研究成果可为蜂窝纸板的合理使用及多目标优化提供依据。     

泡沫填充型蜂窝纸板面外压缩性能实验研究

对泡沫填充型蜂窝纸板的面外压缩性能及其影响规律进行了试验研究。将不同密度的聚氨酯泡沫以不同填充方式填充入不同边长的蜂窝胞元中,以不同的压缩速率对上述泡沫填充型蜂窝纸板进行准静态压缩试验,结果发现:蜂窝胞元边长显著影响泡沫填充型蜂窝纸板的面外压缩性能,初始峰值应力和平台应力均随着胞元边长的增大而减小;当使用低密度(高发泡倍率)的泡沫填充蜂窝纸板时,初始峰值应力和平台应力均优于高密度(低发泡倍率)泡沫填充型蜂窝纸板;部分填充和完全填充的泡沫填充型蜂窝纸板相对于未填充的蜂窝纸板的平台应力和吸能性能均有大幅提升,不但降低了初始峰值应力,还提高了平台应力,对面外压缩性能和缓冲性能改善明显;在2 mm/min~50 mm/min的压缩速率区间内,泡沫填充型蜂窝纸板面外压缩性能受压缩速率的影响不显著。本文的研究成果可为蜂窝纸板的合理使用及多目标优化提供依据。     

组合瓦楞纸板抗弯性能研究

采用瓦楞纸板及其组合衬垫代替非环保的泡沫塑料衬垫进行缓冲包装设计,是今后绿色缓冲包装设计的发展趋势.首先采用淀粉胶将瓦楞纸板试样进行黏结,构造不同结构的组合结构,然后研究环境湿度对组合结构抗弯性能的影响.研究结果表明.B型与AB型瓦楞纸板的黏结组合(B AB)的抗弯强度随湿度的增大显著降低;在A型瓦楞纸板的3层顺向粘结组合(AAA)中,瓦楞的走向与受压位置对纸板的抗弯性能起着决定性的作用,横向抗弯强度大于纵向.     

钙塑瓦楞复合纸板性能的实验研究

钙塑瓦楞纸板是将普通瓦楞纸板的芯纸替换为钙塑材料而成,该材料除普通瓦楞纸板的优点外,还具有强度高、防潮等性能。通过实验方法,对3层钙塑瓦楞复合纸板平压强度、边压强度和戳穿强度进行了测试分析,同时将钙塑瓦楞复合纸板与普通5层瓦楞纸板性能进行了对比。结果表明,3层钙塑瓦楞复合纸板的边压强度为0.650 kN,平压强度为1.274 kN,戳穿强度为7.5 J;5层瓦楞纸板的边压强度为0.378 kN,平压强度为0.437 kN,戳穿强度为6.75 J。为该新材料的推广使用提供了依据。     

SiO2气凝胶改性瓦楞纸板性能研究

目的应用SiO₂气凝胶疏水隔热水性涂料对瓦楞纸板表面进行改性,探究其对瓦楞纸板力学性能、疏水性能、隔热性能的影响。方法通过机械共混和表面改性相结合的方式制备疏水隔热水性涂料,采用线棒涂布器涂布于瓦楞纸板表面,通过测试纸板表面的接触角检验疏水效果,并测试改性后纸板的边压强度、平压强度、戳穿强度和压痕强度;制备90 mm×90 mm×100 mm的隔热包装箱,通过融冰试验测试其隔热效果。结果经SiO₂气凝胶疏水隔热水性涂料改性后的纸板接触角为91.75°,提高了6.25°。改性后纸板的横向边压强度、平压强度、戳穿强度和纵向压痕强度分别提高了5.6%,0.6%,2.4%和2.7%。当SiO₂气凝胶的质量分数为2%时,改性后的纸板具有最优的隔热性能。当湿膜厚度为60μm时,与未涂布的原瓦楞纸板相比,温度可降低13.6℃结论该方法扩大了SiO₂气凝胶在包装行业的应用范围,能为未来保温包装材料提供参考。     

纳米SiO2疏水涂层对纸和纸板性能的影响

目的对牛皮纸及瓦楞纸板进行纳米SiO_2疏水涂层处理后,探讨其对纸或纸板性能的影响。方法将纳米SiO_2和有机硅树脂混合制成疏水涂层,浸渍、喷涂于牛皮纸及瓦楞纸板表面,通过测试纸张接触角及可勃吸水值检验疏水效果,并测试纸张的抗张强度、耐折度、撕裂度、耐破度及检验瓦楞纸板的边压强度、平压强度、戳穿强度等物理性能。结果经表面混合树脂处理的疏水纸张的接触角为88.6°,可勃吸水值大大降低。随着涂层层数的增加,牛皮纸耐破度及瓦楞纸板平压强度均整体随之增长。经双涂层涂饰处理后瓦楞纸板的各物理性能均有较大提高,纳米SiO_2双涂层瓦楞纸板较单涂层瓦楞纸板力学性能更优良。结论纸张及纸板经纳米SiO_2疏水涂层处理后,不仅在一定程度上提高了纸张与纸板的疏水性能,对纸张与纸板的物理性能也有一定程度的改良,为实现纸或纸板的防水包装提供了一定的理论基础与处理方法。     

新型叠层结构瓦楞纸板设计及其动态性能研究

目的 设计一种新型叠层结构瓦楞纸板,解决传统瓦楞纸板耐反复冲击性能较差等问题,获得缓冲及防振性能提升的包装用新型瓦楞纸板。方法 首先设计新型纸板芯纸结构;其次设定新型纸板和传统纸板参数,并手工制作试样;最后对这2种纸板分别进行动态缓冲性能试验和随机振动试验,对比分析2种纸板性能。结果 动态缓冲性能对比试验表明,在不同跌落高度下新型纸板的缓冲性能优于传统纸板;在反复冲击条件下,新型纸板的累积缓冲性能亦优于传统纸板的。随机振动试验表明,新型纸板的减振区间为63.4～200 Hz,而传统纸板在5～200 Hz内无减振现象;新型纸板在40 Hz左右的振动传递率达到峰值4.2,传统纸板的固有频率为163 Hz,新型纸板在此频率下弹性模量相对较小;新型纸板用于公路、铁路运输包装设计时应避开40Hz的共振频率。结论 与传统纸板相比,新型纸板的动态缓冲性能及减振性能均有提升。     

瓦楞纸板和蜂窝纸板的性能比较

<正>将面纸、芯纸相同,用纸量相同,芯层与面纸之间粘合的胶也相同的瓦楞纸板和蜂窝纸板做性能测试,测试结果如下:(1)蜂窝纸板的平压强度远高于瓦楞纸板,而且在耗材量一定的情况下,蜂窝纸板的平压强度随着孔径的增大而减少。     

Effect of polyethylene glycol on the mechanical property, microstructure, thermal stability, and flame resistance of phenol–urea–formaldehyde foams

In this study, polyethylene glycol (PEG) was added to phenol–urea–formaldehyde foam to improve its toughness, and the effects of PEG, with different molecular weights and dosages, on the mechanical property, microstructure, thermal stability, and flame resistance of phenol–urea–formaldehyde foam were studied. The addition of PEG significantly increased the toughness and impact strength and decreased the pulverization rate of the foam. The compression strength of the foam first increased and then decreased with increasing amounts of PEG. When 2 wt% PEGs were added, the compression strength of foams was the highest. The addition of PEG significantly influenced the microstructure of phenol–urea–formaldehyde foams, in which the cell diameter decreased and wall thickness increased with increasing amount and molecular weight of PEG. The addition of PEG also slightly decreased the thermal stability of phenol–urea–formaldehyde foams, and increased the heat release rate, total heat release, and total smoke release of the foams.     

Experimental investigation of interaction effects in foam-filled thin-walled aluminum tubes

The interaction coefficients of polystyrene foam filling of thin-walled aluminum cylindrical tubes were investigated experimentally through compression testing of partially foam-filled tubes with and without adhesive. The experimental load-displacement curves and observation of the crushed sections of filled tubes have shown that partial foam filling reduced the fold length and hence increased the average crushing loads of tubes, proving the interaction effect between tube wall and filler. The interaction coefficients for the partial foam filling were further calculated to be in the level and/or higher than that of the foam plateau load of transverse direction.     

成型工艺对瓦楞纸箱强度影响的实验研究

对不同规格瓦楞纸箱的平压强度、边压强度、粘合强度和戳穿强度进行了试验,分析成型工艺对瓦楞纸箱强度的影响.结果表明:瓦楞纸箱的成型工艺对其强度有一定的影响,它会使瓦楞纸箱的平压强度、边压强度、粘合强度和戳穿强度等有不同程度的降低.此结论为瓦楞纸箱生产企业提供必要的实验数据,指导纸箱成型工艺的改进.     

相变装置中填充泡沫金属的传热强化分析

通过对泡沫金属结构的分析，将泡沫金属结构简化为二维的循环扩展六边形网格形式，且传热单元被分为九个导热层。在此基础上以热阻分析推导出了在泡沫金属作为填充材料时其整体有效导热系数Koff与泡沫金属空隙率ε之间的数学关系式。分别以泡沫铜、泡沫铝填充石蜡为例与用铜、铝翅片并联和串联两种方式填充石蜡时的有效导热系数进行了计算对比，从计算结果可以明显看出采用泡沫金属作为填充材料，其整体效果要优于翅片，可显著改善相变储能装置的传热性能及储能效率。     

Semi-rigid biopolyurethane foams based on palm-oil polyol and reinforced with cellulose nanocrystals

In this study, water-blown biopolyurethane (BPU) foams based on palm oil were developed and cellulose nanocrystals (CNC) were incorporated to improve the mechanical properties of the foams. In addition, the foams were compared with petroleum polyurethane (PPU) foam. The foam properties and cellular morphology were characterized. The obtained results revealed that a low-density, semi-rigid BPU foam was prepared using a new formulation. CNC as an additive significantly improved the compressive strength from 54 to 117 kPa. Additionally, cyclic compression tests indicated that the addition of CNC increased the rigidity, leading to decreased deformation resilience. The dimensional stability of BPU foams was increased with increasing CNC concentration for both heating and freezing conditions.Therefore, the developed BPU nanocomposite foams are expected to have great potential as core material in composite sandwich panels as well as in other construction materials.     

空心玻璃微球表面接枝聚苯乙烯及其性能研究

空心玻璃微球表面改性有利于改善其与基体间的相容性,提高复合泡沫性能.通过接枝聚苯乙烯对空心玻璃微球进行表面处理,采用SEM、IR、热失重等方法分析了反应条件对接枝的影响.结果表明,接枝反应过程中提高反应温度、延长反应时间有利于接枝率的提高,但温度过高会加速单体自聚,降低接枝率.接枝处理后,随着聚合物层的增厚,空心玻璃微球表面缺陷减小,破损率降低,抗压强度得到一定程度提高.     

Effect of the interface bonding on the mechanical response of aluminium foam reinforced steel tubes

Aluminium foams have been recently proposed as filling reinforcements to improve impact behavior of hollow components used as protection systems in vehicles. In this study, aluminium foam filled stainless steel tubes have been prepared by directly foaming metal powder compacts inside the tubes. Attention was concentrated on the interface phenomena that characterize the core–shell interaction and the process parameters determining the metallurgical reactions between the two alloys. The formation of binary and ternary intermetallic compounds was observed at the aluminium/steel interface whenever the growth of the oxide layer on the foam surface in foaming was constrained. Compression tests of the reinforced tubes confirmed a maximized energy absorption in coincidence with the formation of the interface bonding. In those cases, extended foam intrusions into compressed tube folds were observed. The microstructural investigation revealed that in the transition zone the intermetallic layer strength was comparable to that of the foamed matrix.     

泡沫铝填充管的研究进展

泡沫铝填充管是在一个或多个不同横截面形状的薄壁金属管内填充泡沫铝而形成的一种结构功能一体化材料。泡沫铝的填充不仅提高了薄壁金属管的轴向压缩性能和抗弯曲性能,也避免了泡沫铝本身强度不高的劣势。从泡沫铝填充管的制备、结构及性能方面综述了其研究现状,从泡沫铝单管、双管与多管填充的角度分析了结构对泡沫铝填充管压缩和弯曲性能的影响。单管填充泡沫铝改变了薄壁管压缩及弯曲的失效形式,提高了薄壁管的吸能性;双管填充泡沫铝的内管多数以同心管形式排列,在管内部所填充的泡沫铝支撑的基础上,内管进一步支撑起泡沫铝填充管的承载和吸能作用,其压缩及弯曲性能较单管填充更为突出;多管填充泡沫铝在双管基础上进行拓展,可以同心或并列排布,对薄壁管性能的提升各有不同,平行排列的多管结构能量吸收效率高于泡沫铝填充单管,但低于相应的薄壁空管结构。泡沫铝填充管的制备技术通常是分别制取泡沫铝和管材再进行填充,尽管过于单一且工艺复杂,但由于其具有优异的承载和吸能能力,仍然在交通运输、航空航天等领域极具应用潜力。     

Extrusion of starch‐based loose‐fill packaging foams: effects of temperature,moisture and talc on physical properties

Starch‐based loose‐fill packaging foams were made in a single‐screw laboratory‐scale extruder. Corn starch was blended with polystyrene in the ratio of 70 : 30 and extruded into foams using talc and polycarbonate as additives. Extrusions were carried out at moisture contents of 16, 18 and 20% (dry basis), and at barrel temperatures of 140 and 160°C. The influences of extrusion temperature, moisture content of starch, talc and polycarbonate on the radial expansion and other selected physical properties of starch foams were investigated. The effects of moisture and talc contents on the radial expansion of foams were found to be critical, while the role of temperature was close to significant. The expansion ratio increased when the moisture content was increased from 16 to 18%, and then decreased when moisture content was increased to 20%. In general, the expansion ratios of foams were higher at 160°C as compared to 140°C. Although polycarbonate mixed well with the starch–polystyrene melt, it was not effective as a structural and anti‐shrinking agent, and it did not contribute to the radial expansion. In general, the bulk densities and unit densities of the starch foams decreased as the moisture content and extrusion temperature increased. Scanning electron microscope images showed that the addition of talc yielded foams with smaller‐sized cells, with less expansion of the foam melt, and thus a higher density. X‐ray diffractograms revealed that the crystallinity of starch foams increased post‐extrusion, and there was adequate dispersion of the starch and polystyrene polymers to make the foam water‐resistant. Copyright © 2008 John Wiley & Sons, Ltd.     

Deformation mechanisms and the yield surface of low-density,closed-cell polymer foams

The geometry of low-density, closed-cell, polyethylene and polystyrene foams was modelled with a Kelvin foam having uniform-thickness cell faces; finite element analysis (FEA) considered interactions between cell pressures and face deformation. Periodic boundary conditions were applied to a small representative volume element. In uniaxial, biaxial and triaxial tensile stress states, the dominant high-strain deformation mechanism was predicted to be tensile yield across nearly flat faces. In uniaxial and biaxial compression stress states, pairs of parallel plastic hinges were predicted to form across some faces, allowing them to concertina. In hydrostatic compression, face bowing was predicted. The rate of post-yield hardening changed if new deformation mechanisms became active as the foam strain increased. The effects of foam density and polymer type on the foam yield surface were investigated. Improvements were suggested for foam material models in the FEA package ABAQUS.