EPO材料缓冲性能的探究

目的通过试验对比EPE,EPS,EPO等3种材料缓冲性能的优劣。方法对一定规格的3种材料试样进行静态压缩试验、动态压缩试验,并结合Ansys有限元仿真技术,进行数据处理分析。结果在静态缓冲特性试验中,当材料所受应力大于3.5 kPa且小于180 kPa时,EPO与EPE及EPS的静态缓冲性能系数大小关系为EPEEPOEPS;当应力小于3.5 kPa或者大于180 kPa时,EPO的静态缓冲系数最小,即此时EPO的静态缓冲性能优于EPE和EPS。从动态缓冲特性试验中可知,静应力小于10 kPa时,3种材料的缓冲性能大小为EPSEPOEPE;当静应力大于14kPa时,缓冲性能大小排序为EPSEPOEPE;静应力大小介于10 kPa和14 kPa之间时,3种材料具有相似的缓冲效果。EPO材料动态缓冲特性处于EPE以及EPS之间,当静应力较大时,EPO呈现出与EPE更相近的性能,缓冲性能较EPS有所提升。结论经测试比较,EPO材料具有较好的缓冲性能,某些环境下可以作为新缓冲包装材料使用,未来有较好的发展前景。     

疲劳振动效应对瓦楞纸板承载能力与缓冲性能的影响

瓦楞纸板作为产品运输包装的承载与缓冲基础材料,其使用过程中的性能保持性至关重要。运输振动将引起纸板疲劳破损,导致其相应性能的变化。对单瓦楞纸板进行加速度为0.5－2.0g、振动频率为20Hz的疲劳振动试验;进行瓦楞纸板的准静态压缩、跌落冲击试验,测定其承载能力与冲击加速度。结果表明,随着振动次数、振动强度的增加,纸板的承载能力、剩余屈服应力显著降低,缓冲性能下降。在此基础上,基于瓦楞纸板冲击试验数据,分析不同振动次数对瓦楞纸板的冲击最大加速度和缓冲系数的影响,获得了瓦楞纸板冲击最大加速度—静应力—振动次数、缓冲系数—最大应力—振动次数三维关系。研究表明瓦楞纸板存在疲劳破坏效应,研究结果为瓦楞纸板的疲劳缓冲包装设计提供技术依据     

基于静态压缩实验的包装缓冲材料性能研究

发泡聚苯乙烯（EPS）和发泡聚乙烯（EPE）缓冲包装材料都是粘弹性材料。本实验模拟了这两种缓冲材料在包装件中的使用情况。通过应力-应变曲线和缓冲系数最大静应力曲线对比分析了EPS与EPE在预压缩前后表现出来的力学性能和缓冲性能。为缓冲包装设计起到一定的指导意义。     

植物纤维衬垫缓冲性能的研究

通过植物纤维衬垫的静态压缩试验,对其缓冲性能进行了研究;并绘制出植物纤维衬垫的C-σm曲线、C-ε曲线、C-E曲线供缓冲设计用.     

不同规格蜂窝纸板缓冲性能的研究

通过静态压缩和动态压缩试验,研究蜂窝纸板的静态缓冲特性和动态缓冲特性与它的蜂窝芯柱、蜂窝孔径的关系.根据静态压缩试验所得的应力-应变曲线计算出蜂窝纸板的缓冲系数-应变曲线,根据动态压缩试验所得的最大加速度-时间曲线计算出缓冲系数-静应力曲线,为包装中蜂窝纸板的尺寸设计提供一定的参考.     

纸质缓冲材料能量吸收特性研究进展

综述了两类常用纸质缓冲材料能量吸收特性的研究进展,从缓冲吸能影响因素及规律两方面总结国内外研究侧重点和取得的成果,并着重就环境湿度和应变率对纸质缓冲材料吸能特性影响的研究现状进行了阐述。提出考虑环境湿度和应变率,建立蜂窝纸板和瓦楞纸板能量吸收理论预报模型,构建兼具普适性、准确性和简便性的纸质缓冲材料吸能特性表征方法,并应用于缓冲包装优化设计中,是今后研究的重点。     

玉米秸秆缓冲包装材料动态缓冲性能的研究

研究了以玉米秸秆和淀粉为主要成分的新型缓冲包装材料的动态缓冲性能,利用动态跌落测试采集和数据处理程序对试验数据进行处理,得到了材料的加速度时间曲线、最大加速度与厚度和跌落高度的响应面立体分析图、最大静应力与厚度和跌落高度的响应面立体分析图、缓冲系数与厚度和跌落高度的响应面立体分析图.     

硒鼓缓冲气柱包装冲击响应与变形行为的图像测量分析

硒鼓是高精密感光成像装置,在运输过程中易由于不慎跌落而造成破损。因此对硒鼓的缓冲包装性能进行评价具有重要的应用价值。本文通过对硒鼓缓冲气柱包装件进行冲击试验,研究硒鼓的冲击响应和缓冲气柱包装的缓冲特性。文中采用高速图像测量技术和数字图像处理方法,测量HP Q2612A硒鼓在五种冲击强度条件下的动力学响应,同时测量与分析缓冲气柱衬垫全场变形行为和特征。通过这些测试分析将有助于确定包装的缓冲效果,为改进缓冲包装设计提供了重要的依据。     

竹纤维发泡缓冲材料的研究

研究以竹纤维为原料,使其在水混合态中搅拌引起帚化,发泡剂在一定温度条件下分解产生气体,加入胶粘剂使纤维定向、结合,后在其他助剂作用下,形成很多小孔从而达到减小密度的目的,然后通过合适的干燥工艺,使材料具有开孔结构从而有一定的机械强度与缓冲性能的方法.最终对制品的外观和内部形貌进行表征,并对其性能进行研究并绘制出相应的F-x曲线、σ-ε曲线和c-ε曲线供缓冲设计用.     

Development of an air cushioning material based on a novel idea

The air cushioning material introduced in this paper as a new packaging material represents a new steadying and cushioning system using air pressures. The material is a two‐layer structure consisting of an airtight chamber (air chamber) filled with air and a urethane chamber holding flexible and resilient urethane that permits free air passage. Ordinary air cushioning materials have drawbacks in that they repeat expansion and contraction according to changes in atmospheric pressure and temperature during long storage or transportation to remote destinations. While their expansion may damage the case or the packaged object, their contraction may cause a drop in steadying pressures, so that the contents may move about inside and eventually sustain damage. The two‐layer structure of the new material rectifies the shortcoming of ordinary air cushioning materials that they may be affected greatly by temperature changes. Also, the greatly improved flexibility of the packaging material opens up possibilities for far wider applications in packaging precision devices and machinery. The airtight chamber to be filled with air is provided with an air charge port and an air discharge port, which may be used to control the charged air pressure. The desirable air pressure is such that the urethane in the urethane chamber is compressed to about half the ordinary size. Since it can be checked visually or tactually, the charging of air, which used to be a delicate and rather difficult operation, is easy. Conventionally, most of the packaging materials were of throw‐away type and thus handled as waste materials. The new air cushioning material, which is surfaced with a strong wear‐resistant cloth, is designed for repetitive use, so that it will contribute greatly to the reduction of wastes if systematic recovery is carried out. Copyright © 1999 John Wiley & Sons, Ltd.     

The effect of compression of enclosed air on the cushioning properties of corrugated fibreboard

This work showed that the shock‐absorbing properties of corrugated fibreboard are dependent on the size of the cushion even when the static loading of the impacting product on the cushion is kept a constant. At least part of this phenomenon was found to be due to the effect of the air enclosed within the flutes of fibreboard cushions. During the dynamic compression of fibreboard pads there is a build‐up of air pressure within the cushion, which improves its cushioning performance. The greater ease with which air can escape smaller fibreboard cushions, leads to differences in their shock‐absorbing behaviour compared with larger cushions. Suggestions are made on how the design of fibreboard pads can be modified to increase the build‐up of air pressure within the flutes and improve the efficiency of the cushion. For comparison, expanded polyethylene foam was also examined and its shock absorbing properties were found to be largely independent of cushion size for constant static‐loading impacts. Copyright © 1999 John Wiley & Sons, Ltd.     

多孔材料缓冲吸能特性表征方法

分析了多孔材料缓冲吸能机理，综述了多孔缓冲材料吸能特性的几种表征方法：缓冲曲线、缓冲系数、Janssen因子、Rusch曲线、能量吸收率曲线和能量吸收图，并分析了各种表征方法的优缺点。能量吸收图汇集了应变率和材料结构特征等信息，且能够模型化，对于不同密度多孔材料吸能特性的表征具有一定的普适性。     

基于光电伺服平台的动态角度测量方法研究

针对动态角度测量的成本高及精度低的问题,提出一种基于非合作目标视觉跟踪的光电测量方法。利用安装在被测对象上的光电伺服平台搭载相机和激光测距仪对非合作目标进行实时跟踪和距离测量,根据伺服平台输出的精密角度、非合作目标距离和被测角度之间的转化关系计算出被测动态角度值。研制了基于光电伺服平台的动态角度测量装置,并对其进行了精度标定和误差分析。利用高精度旋转台模拟被测动态角度进行实验,验证了测量方法的可行性。实验结果表明在测量空间11.082 m范围内,测角误差在±0.09°以内。     

溶解浆纤维增强缓冲材料的制备及其性能研究

随着日益增长的环保要求,来源于植物源的可降解缓冲包装材料的使用和开发引起了广泛的关注。鉴于此,本文以3种不同植物源的商业溶解浆为原料,基于其在NaOH/尿素水溶液中的溶解,通过模塑成型-再生进行了溶解浆纤维增强缓冲包装材料的制备研究。通过模塑成型材料干燥前后径向与厚度方向尺寸的测量,比较了不同助剂制备的缓冲材料的径向收缩率与厚度方向的收缩率,借助扫描电镜观察了制备的材料的断面形貌,通过拉伸试验绘制应力-应变曲线来分析浆纤维缓冲材料的力学性能,通过振动缓冲性能测试比较了制备的材料的振动缓冲性能。结果表明在7%NaOH/12%尿素水溶液中溶解和在99.5%CH3COOH中再生制备的材料比较柔软、再生容易。另外阔叶木溶解浆纤维制备的缓冲材料较硬,针叶木溶解浆纤维制备的缓冲材料和添加淀粉的竹溶解浆纤维制备的缓冲材料具备一定的振动缓冲性能。添加淀粉制备的竹溶解浆纤维缓冲材料的径向收缩率和厚度方向收缩率都是较小的,且有35%的延伸率。     

Comparison of various loose fill cushioning materials based on protective and environmental performance

This paper compares various loose fill packaging materials based on the amount of material required for a given level of protection. A methodology developed to evaluate and compare package cushioning materials on the basis of environmental concerns relative to disposal and recycling is used to compare seven different loose fill materials. The materials compared include recycled expanded polystyrene (EPS), starch and paper based materials, wood shavings and popcorn. The shock level G was related to the amount of cushion material needed both by weight and by volume. The results show that starch-based loose fill materials (Naturpack and Eco-Foam) and Fiberflow showed the best protective performance and minimum material utilization by volume. 100% recycled EPS showed the best performance in terms of percent weight utilization. Other materials tested, like popcorn and wood shavings, showed poor material utilization.     

流动颗粒显微图像测量技术研究

针对显微环境下流动颗粒测量的需要,构建了测量平台,研制了基于MEMS工艺的测量器件。在分析流动颗粒显微图像特征的基础上,提出了基于颗粒运动特性的图像测量流程,其中提出了基于基准桢差分的目标提取算法,解决了流动颗粒目标分割的问题,根据图像运动模糊的退化模型,研究了图像模糊恢复的问题。最后以润滑油中的磨损颗粒为例,验证了该文的分析方法对流动颗粒检测的有效性。     

Application of digital image analysis to strain measurement at elevated temperature

Digital imaging techniques are applied to the measurement of surface displacement and strain at elevated temperatures. A simple surface preparation using high temperature paint together with a CCD video camera for digital imaging serve as the basis for the measurements. Mathemetical correlation of the surface intensity pattern between reference and deformed states is used to measure local surface deformation. The method is non-contacting and full field. Displacement and strain measurements have been made at temperatures to 600°. Coefficients of thermal expansion of three metals have been measured using this technique and compared to strain gauge and handbook values. Limitations and potential extensions of the method are discussed.     

Anisotropy of Gum Metal analysed by ultrasonic measurement and digital image correlation

ABSTRACT

The mechanical anisotropy of a multifunctional titanium alloy, Gum Metal, is investigated in this paper. The structural characterisation showed a strong <110> texture for Gum Metal, that is a result of the cold-swaging process applied during its manufacture. Gum Metal was treated as a transversally isotropic solid because of this texture. A significant difference from Young’s moduli of the alloy was detected from the ultrasonic measurement of parallel and perpendicular directions to the alloy swaging direction. Samples of Gum Metal cubes were compressed in two different orientations. During the deformation process, two perpendicular walls of each sample were monitored by two visible range cameras for further two-dimensional digital image correlation analysis, this confirmed a strong plastic anisotropy in Gum Metal.

This paper is part of a Thematic Issue on The Crystallographic Aspects of Metallic Alloys.