瓶体内表面制备类金刚石膜流场结构的格子波尔兹曼模拟

类金刚石膜(Diamond-like Carbon,DLC)具有优异的气体阻隔性能.在PET瓶体内表面制备DLC阻隔涂层时,阻隔涂层的均匀性会受到瓶体内流场结构(气压分布、速度分布等)的显著影响.本文应用格子波耳兹曼方法(Lattice Boltzmann Method/Model,LBM)对PET瓶体内制备DLC阻隔涂层时的流场结构进行模拟,研究了送气速度、气体运动粘度系数和装置结构变化时瓶体内部流场结构的变化.研究结果表明,降低进气速度和提高气体运动粘度系数有利于减弱回流而获得层流结构;装置结构的调整能够改变瓶体内的流场结构,采用恰当的异型装置可以获得较理想的流场结构,对实验工作具有一定的指导意义.     

射频等离子体沉积非晶碳氢薄膜及其阻隔性能

采用射频辉光放电等离子体化学气相沉积系统,,以甲烷和氩气作为工作气体在PET(聚对苯二甲酸乙二醇酯)片和玻璃片基上沉积了非晶碳氢薄膜,利用傅立叶变换红外光谱(FTIR)对碳氢薄膜的结构进行研究,并且通过透水蒸汽相对比较实验检测了PET上沉积碳氢膜的阻隔性能,详细讨论了沉积工艺参数对碳氢薄膜结构和阻隔性能的影响.实验结果证明,沉积的薄膜越厚,碳氢膜的含量越高,阻隔性能越好,沉积碳氢膜的PET阻隔性比原始PET都有明显提高,当膜厚达900nm时,阻水蒸汽透过率可提高7倍.     

聚对苯二甲酸乙二醇酯/石墨烯的氧气阻隔性能

通过熔融共混和微型注塑成型的方法制备了不同石墨烯(RGO)含量的聚对苯二甲酸乙二醇酯(PET)纳米复合材料。研究了不同注塑压力条件下,PET/RGO纳米复合材料的气体阻隔性能。结果表明,与纯PET相比,添加质量分数0. 5%的RGO,复合材料的氧气渗透率降低了85%。在微型注塑加工过程中,随着注塑压力增加,RGO在基体中取向,能够延长氧气的渗透路径,进而在较低RGO添加量的情况下能有效提高PET/RGO氧气阻隔性能。     

单层PET瓶开发将加快啤酒塑料包装步伐

啤酒对环境高度敏感,因此要求包装材料具有很高的阻隔性能,PET瓶生产商通常用以下方法来解决:在多层瓶壁内添加阻隔层;通过共混或使用添加剂改进PET瓶性能;使用SiOx等离子涂层。但无论使用哪种方法,最大的挑战就是如何以最低的成本产生最佳的阻隔性。用上述方法生产的多层PET瓶     

瓶装水包装走向轻质化

PET是非常安全的食品包装材料,已经得到国际的广泛认可。PET即聚对苯二甲酸乙二（醇）酯,是一种耐压性聚酯材料,价格便宜,透明性、气密性和耐压强度好以及能很好的阻隔二氧化碳、氧气和水等。自上世纪80年代开始,PET瓶作为玻璃和PVC瓶的替代品被广泛使用,目前全世界大约要使用3000亿个PET瓶。     

荧光照射下PET阻隔瓶对杀菌乳风味的保护研究

目的 研究分析添加质量分数为8%的阻光色油的PET瓶（简称阻光8%PET瓶）包装对杀菌乳风味物质组成和含量的影响,为杀菌乳保质期的延长提供数据支撑。方法 模拟超市货架光照情况,以纯PET瓶和阻光8%PET瓶包装做对比,分析不同贮存期杀菌乳感官风味指标变化及特征风味物质组成及含量变化。结果 相对纯PET瓶杀菌乳,阻光8%PET瓶杀菌乳,光照3、7 d后两样品关键感官特性指标（奶香气、奶腥味、异味强度）及整体喜好度平均值均表现出显著性差异（P<0.05）,阻光8%PET瓶杀菌乳的奶香气、整体喜好度评价均优于纯PET瓶杀菌乳的,奶腥味、异味强度均低于纯PET瓶杀菌乳的。经特征风味化合物分析,醛类化合物对杀菌乳异常风味贡献最大,酸类、酮类、醇类物质贡献较小。结论 阻光8%PET瓶包装能有效延缓光照31 d贮存期杀菌乳产品醛类物质的种类和含量的迅速增加,能一定程度减少部分酸类、酮类、醇类物质的增加,从而减少异常风味,提高产品的喜好度,可一定程度延长杀菌乳的货架期。     

阻隔性包装材料的动向(上)

前言食品包装技术和食品包装材料的一大特征是追求食品的美味与安全性,同时还需要延长包装食品的货架期,基于这样的需求,推动了各种阻隔性包装材料和包装技术的开发。此外,用于饮料包装的PET瓶,也开发了各种阻隔型产品。本文介绍惰性阻隔性材料、活性阻隔性材料以及PET瓶的开发动向与使用情况。1、惰性阻隔性材料的开发动向     

PET碳酸饮料瓶货架期的快速评估测试方法研究

针对瓶装碳酸饮料流转迅速、货架期长、检验周期无法满足生产和销售需要这一问题,使用红外传感检测二氧化碳浓度,建立了快速检测碳酸饮料货架期的方法。试验表明:使用红外传感测试和数学推导可以大大缩短检测时间,同时测试重复性有所提高,该方法可以满足企业快速生产、销售的需要,也可以保证下游灌装企业能够准确地预估产品的货架周期,保护消费者利益;红外传感法还可以测试温度对于二氧化碳渗透量的影响,从而为碳酸饮料较严峻储存环境下的存放周期提供测试分析方法。     

基于SolidWorks的中空塑料包装容器耐内压强度有限元分析

目的研究在不同壁厚、不同直径条件下,中空塑料包装容器承载内压强度的能力。方法主要通过Solid Works软件设计出了不同壁厚、不同直径和不同结构的包装容器3D模型,然后进行了有限元分析。结果通过多次试验和数据处理,得出了塑料包装容器承载内压强的能力与包装瓶壁厚、直径之间的关系公式。结论经过测试发现在碳酸饮料灌装压力0.5 MPa的条件下,包装容器壁厚至少要大于1.5 mm,瓶体才不会破裂,测试结果也为今后中空塑料包装容器的设计提供了一定的参考。     

回收物含量和rPET质量对PET瓶性能的影响

再生聚酯(r PET)的含量和类型对浑浊度的影响颜色参数L~*,a~*,b~*;总颜色变化;紫外-可见光谱(UV-VIS)吸收;对PET瓶进行了环境应力开裂试验研究。在小型生产设备上,用同类型的初级PET和三种不同类型的r PET生产了3个系列的PET瓶,回收含量分别为25%、50%、75%和100%。采用溶解瓶片和计数不溶性颗粒的方法,研究了生产的PET瓶的颗粒污染情况。PET瓶的浑浊度与颗粒污染呈线性关系,测定系数为0.96。PET瓶的颜色参数L~*和b~*与颗粒污染之间也存在线性关系,但每种r PET的斜率不同。r PET (monocollection或cocollection)的来源似乎是决定生产的瓶子的颗粒污染和颜色的关键因素。回收物含量与ESC发生率无相关性。然而,高特性粘度(IV)值的PET瓶比低特性粘度(IV)值的PET瓶更容易发生ESC。     

Acetaldehyde in Mineral Water Stored in Polyethylene Terephthalate (PET) Bottles: Odour Threshold and Quantification

The use of PET bottles for packaging soft drinks and mineral waters is still growing world wide. The production process for these bottles is improving constantly. These improvements are focussed on bottles with better barrier properties, higher inertness and higher heat stability. One of the factors determining the quality of PET bottles is the release of acetaldehyde into the product during storage. A literature survey was conducted on the odour and taste detection threshold of acetaldehyde in water. A method is described to rapidly determine the concentration of acetaldehyde in water up to a level of 1 μg/l. This method was used to determine the concentration of acetaldehyde in mineral water during storage in PET bottles. In still water no acetaldehyde could be found, whereas the concentration of acetaldehyde in carbonated mineral water increased steadily upon storage. Model experiments were performed to find an explanation.     

Quantification of the Sorption Behavior of Polyethylene Terephthalate Polymer versus PET/PA Polymer Blends towards Organic Compounds

Polyethylene terephthalate (PET) bottles are widely used for beverages. Oxygen‐sensitive beverages, however, often require the use of barrier materials or oxygen‐scavenging additives incorporated into the PET material, which is in most cases polyamide (PA). As a consequence, small amounts of polyamide are entering the PET bottle‐to‐bottle recycling feedstream. Aim of the study was therefore the determination of the sorption behavior of bottles made of different PET/PA blends in comparison with a PET reference. As a result, PET test bottles containing blended PA amounts of up to 1000 ppm do not show a sorption behavior for the investigated model compounds, which is different from pure PET material. Therefore, polyamide impurities in the recycling streams coming from polyamide barrier bottles will not lead to a different sorption/remigration behavior as pure PET bottles. Consequently, evaluations of PET recycling processes will still be valid for feedstream materials containing such small amounts of polyamide from barrier bottles. On the other hand, the introduction of 8% of polyamide decreases significantly the sorption of organic compounds into the bottle wall. Copyright © 2011 John Wiley & Sons, Ltd.     

Influence of PET bottle weight,closure performance and filling Technique on the oxygen content of soya cooking oil

The use of PET bottles for edible oil in Brazil is increasing but there is a trend to reduce bottle weight for economic reasons, which decreases the oxygen barrier of the package. The barrier performance of a 20 g PET bottle for 900 ml soya oil, submitted to gas flushing with gaseous N₂ and pressurization with liquid N₂, was compared with a 27 g PET conventional bottle. During 8 months storage at 25°C the internal pressure, dissolved oxygen and oxygen in the headspace were evaluated and did not change significantly. Liquid N₂ pressurization did not improve the efficiency of reducing O₂ in the headspace compared to N₂ gas flushing. Copyright © 2001 John Wiley & Sons, Ltd.     

Oxygen permeation in PET bottles with passive and active walls

The aim of this paper is to provide a framework, whereby gas permeation rates through plastic packaging walls, and hence, food shelf life may be estimated. Although the approach is quite general, specific attention is given to the case of liquid‐filled polyethylene terephthalate (PET) bottles with oxygen as the permeating gas. Two situations are considered: when the walls simply provide a passive resistance to the flux (as is the case for standard PET or PET blended with some other low permeability material) and when an active gas scavenger is incorporated within the boundary material. For the passive wall, permeability data relative to oxygen have been collected from literature sources and also measured using specific oxygen transmission rate experiments. For the active walls, scavenger kinetic constants were estimated from data obtained using test bottles prepared with varying scavenger concentrations. Numerical predictions in both cases have been verified by comparison with data on gas concentration in water‐filled bottles maintained under controlled conditions for periods of up to 6 months. Copyright © 2008 John Wiley & Sons, Ltd.     

On‐going solutions to environmental issues in plastic packaging

Recently, the consumption of polyvinyl chloride (PVC) and polyvinylidene chloride (PVDC) resins as packaging materials has been declining in the face of various environmental problems they pose. To replace PVC containers, the use of PET bottles and A‐PET containers is on the increase, but PVDC resins are still in wide use as gas‐barrier materials. For gas‐barrier purposes, however, ethylene vinyl alcohol co‐polymer (EVOH) films, polyvinyl alcohol (PVA)‐coated polypropylene films, and MX nylon or silica‐ or alumina‐coated PET films are becoming mainstream. The weight reduction of plastic bottles is considered to play an important role in tackling the waste disposal problem. Recently, a new type of stretch‐blow moulding system has been developed, which is effective in reducing the weight of PET bottles. This system is called COSMOS (complete stretch‐blow moulding system) or the two‐blow system. COSMOS PET bottles are now used to hold carbonated drinks containing fruit juice or lactic acid. Copyright © 2001 John Wiley & Sons, Ltd.     

Development of plastic bottles resistant to lateral deformation

Plastic bottles are sensitive to lateral wall deformation (panelling) owing to the pressure difference between the inside and the outside. Parameters involved in plastic bottle deformation have been reviewed. A quick laboratory test for measuring bottle resistance to deformation was set up and evaluated vs. real life conditions. Round 1–l bottles with various geometries and wall thickness distributions were designed, produced and tested.     

不同包装橙汁贮藏期间物理品质的变化

以纸铝塑复合包装、普通PET瓶和充氮PET瓶包装的橙汁为研究对象,监测其物理指标,如褐变度、可溶性固形物、pH值、表观黏度及流变特性,在不同温度下贮藏24周过程中的动态变化。结果表明,试验周期内不同包装橙汁褐变度的变化符合一级动力学模型;橙汁的流体性质均属于假塑性流体;pH值随贮藏时间延长而降低;可溶性固形物含量在4℃和20℃下无显著变化(P0.05),而在37℃和55℃下呈上升趋势。研究表明,纸铝塑复合包装可以保持橙汁物理品质相对稳定,而从节约成本和携带方便等方面考虑,充氮PET瓶仍是较优的包装方式。     

涂层技术制备高阻隔性PET瓶的应用研究

对聚偏二氯乙烯、改性聚乙稀醇和环氧-胺等有机涂层材料及氧化硅、类金刚石等无机涂层材料在PET瓶上的应用工艺、阻隔性能及其在国内外市场的研究进展进行了综述,指出高阻隔PET瓶目前仅处于小规模的试用阶段,若要成功实现从玻璃瓶到PET塑料瓶的转化,不仅需要提高PET材料的阻隔性能,还应保证其具有较高的透明性、可回收性、技术易操作性及实用性等。