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热处理过程对PLA薄膜阻隔性能的影响 总被引:1,自引:1,他引:0
目的研究不同热处理对PLA薄膜阻隔性能的影响。方法对用PLA和PE薄膜包装好的食品模拟物进行不同的热处理,分析热处理后PLA和PE薄膜氧气透过量、吸水能力、水分透过量的变化。结果热处理前的PLA和PE薄膜的氧气透过量分别为3737.27和1469.54 cm3/(m2·d·Pa),热处理后因PLA和PE薄膜出现缺陷,在透气性测试仪中测量不出数据。PLA薄膜的水分透过量在80~124g·cm/(cm2·s·Pa)之间,PE薄膜的水分透过量在4.9~29.6 g·cm/(cm2·s·Pa)之间。在蒸煮加热时,当储存时间为3周时,PLA的拉伸强度、透湿量、吸水率都会减小。结论传统的蒸煮加热消毒对PLA的阻隔性能影响最大,不适用于需要蒸煮消毒的食品包装材料。在预测食品货架期时,不应忽视消毒方式对包装材料性能产生的影响。 相似文献
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Labthink兰光作为协作单位参与了国家认监委组织的塑料包装材料阻隔性能测试能力验证项目,并出色地完成了检测试样均匀性、稳定性的重要工作。本文具体介绍了在本次能力验证项目中样品的选择以及进行样品均匀性、稳定性检测的方法和意义。 相似文献
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(上接《塑料包装》2012年第5期)2012年,BOPP薄膜生产企业要大力开发新产品,加强功能性薄膜的开发和应用,开拓新的应用领域。BOPET薄膜具有平整性好、密封性优、耐高温、抗拉强度高、透明度和光泽性好等优点,常被用以复合膜的表层和中间层膜。BOPET薄膜耐化学腐浊的特点,使得容易进行真空镀铝和表面涂布化学改性,从而提高其热封性、阻隔性和印刷的附着力,适用于蒸煮、低温冷冻、耐油性和耐化学 相似文献
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阻隔性能检测应用范围广泛,LABTHINK兰光2014年春季塑料薄膜阻隔性能实验室间比对以塑料薄膜为试样,对现阶段的阻隔性能检测水平进行验证。通过对结果的统计分析,可以看出,现阶段我国塑料薄膜阻隔性能整体检测水平尚属理想,但是检测结果仍具有一定的离散性,部分实验室可疑或离群。在目前阻隔性能检测缺乏统一校准规范的情况下,建议实验室积极进行实验室间数据比对,以使自身实验室数据保持在合适的水平。 相似文献
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《塑料包装》2020,30(1):41-50
前言本标准按照GB/T 1.1—2009给出的规则起草。本标准代替BB/T 0030—2004《包装用镀铝薄膜》。本标准与BB/T 0030—2004相比,除编辑性修改外主要技术变化如下:——修改了标准的英文名称;——修改了规范性引用文件(见第2章,2004年版的第2章);——修改了术语和定义(见第3章,2004年版的第3章);——修改了镀铝薄膜的外观要求(见5.1,2004年版的5.1);——修改了镀铝薄膜的尺寸及偏差要求(见5.2,2004年版的5.2);——修改了镀铝薄膜的断裂标称应变、热收缩率、水蒸气透过量、氧气透过量和镀铝层附着力要求(见5.3,2004年版的5.3). 相似文献
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C. N. Ravi Shankar T. K. Srinivasa Gopal P. K. Vijayan 《Packaging Technology and Science》2002,15(1):3-7
Seer fish in curry medium packed in locally manufactured retort pouches, having a three‐layer configuration of thickness 12.5 µm polyester/12.5 µm aluminium foil/80 µm cast polypropylene was processed in a steam/air mixture over a pressure retort. About 210 g fish curry, having 110 g fish slices, was packed in a retort pouch of size 17 cm × 15.5 cm, each fitted with a thermocouple. Time–temperature data were collected during heat processing using an Ellab data recorder FO and cook value integrator. The heat penetration characteristics were determined using a mathematical method. The fh value was 25 min with a FO value of 11.5 and cook value of 95 min. These samples remained in good condition for up to 24 months at room temperature. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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Xiaotun Qiu Rui Tang Ranran Liu Hai Huang Shengmin Guo Hongyu Yu 《Journal of Materials Science: Materials in Electronics》2012,23(12):2140-2144
This study described a micro initiator realized by reactive Ni/Al nanolaminates. A self-propagating reaction can be triggered in the Ni/Al film by applying a DC voltage of 1.5?V. This exothermic reaction can raise the temperature of the film (10?μm in thickness) surface to as high as 622?K. The measured ignition power to start the self-propagating reaction in the film was 3?mW with an ignition delay of around 0.63?s. The small ignition energy required and the large energy output make the Ni/Al film superior to the current resistive heater based initiators. Numerical simulation results demonstrated that different temperatures can be achieved by simply alternating the film thickness and the localization of high temperature exposure was realized to avoid unintentional fire of adjacent initiators. These findings were confirmed by the experiment using thermal indicators. 相似文献
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本文所采用的包覆液具有良好的润湿性能。在粉末表面形成含有Cr、P元素的玻璃相结构的均匀薄膜,具有较高的电阻率和良好的耐热性能。讨论了粉末表面的光滑度对包覆效果的影响以及磁粉芯的品质因数Q和导磁率μ及绝缘介质含量之间的关系。 相似文献
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Heat processing semi-rigid packages with a steam/air mixture requires an overpressure to ensure seal integrity. A method was developed to calculate the overpressure needed to ensure seal integrity, during thermal processing, of semi-rigid packages that contain a liquid food or drug. An equation was derived relating total retort pressure (steam and air) required during sterilization to retort temperature, product water activity and tensile seal stress at the sterilization temperature. The proposed method was tested, under commercial sterilization conditions (123–127°C for 30min), with individual packages containing a dilute saline solution. The method was found useful for predicting the total retort pressure (steam and air overpressure) needed to ensure seal integrity and to prevent leakage of packages. 相似文献
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渗铝件焊接熔合区的组织与性能 总被引:1,自引:0,他引:1
研究了渗铝件焊接熔合区的组织与性能。结果表明:熔合区内形成金属化合物,并具有很高的耐高温氧化性。蒸馏釜底部加热区焊接渗铝薄板后,使用寿命提高6倍。 相似文献
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Tai-Chang Chen Mike Johnson Kunakorn Poochinda Thomas G. Stoebe N. Lawrence Ricker 《Optical Materials》2004,26(4):417
Wide bandgap semiconductor materials provide superior electrical, optical, and thermal properties that classical semiconductors, Si and GaAs, are unable to achieve. However, most commercially available substrates have large lattice and thermal expansion mismatches to III-nitrides films. Thus a high quality buffer layer, grown at low temperatures, is essential in growing high quality III-nitride films. This research provides a throughout study on III-nitrides, such as AlN, GaN and AlGaN thin films, which were grown at low temperatures (400–600 °C). Growth rate, stoichiometry and crystal structure of low temperature growth films will be reported by using several advanced post-growth analysis techniques. Temperature, pressure, and V/III molar ratio were also investigated to determine their effect on the film properties. From the study, a better understanding of the relationships between film properties and growth parameters will be achieved. 相似文献
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A 1300 mm2 Ultrahigh‐Performance Digital Imaging Assembly using High‐Quality Perovskite Single Crystals 下载免费PDF全文
Yucheng Liu Yunxia Zhang Kui Zhao Zhou Yang Jiangshan Feng Xu Zhang Kang Wang Lina Meng Haochen Ye Ming Liu Shengzhong Liu 《Advanced materials (Deerfield Beach, Fla.)》2018,30(29)
By fine‐tuning the crystal nucleation and growth process, a low‐temperature‐gradient crystallization method is developed to fabricate high‐quality perovskite CH3NH3PbBr3 single crystals with high carrier mobility of 81 ± 5 cm2 V?1 s?1 (>3 times larger than their thin film counterpart), long carrier lifetime of 899 ± 127 ns (>5 times larger than their thin film counterpart), and ultralow trap state density of 6.2 ± 2.7 × 109 cm?3 (even four orders of magnitude lower than that of single‐crystalline silicon wafers). In fact, they are better than perovskite single crystals reported in prior work: their application in photosensors gives superior detectivity as high as 6 × 1013 Jones, ≈10–100 times better than commercial sensors made of silicon and InGaAs. Meanwhile, the response speed is as fast as 40 µs, ≈3 orders of magnitude faster than their thin film devices. A large‐area (≈1300 mm2) imaging assembly composed of a 729‐pixel sensor array is further designed and constructed, showing excellent imaging capability thanks to its superior quality and uniformity. This opens a new possibility to use the high‐quality perovskite single‐crystal‐based devices for more advanced imaging sensors. 相似文献