存储环境条件对包装材料阻隔性能的影响分析

阻隔性能是包装材料的重要性能指标,对所包装产品的质量具有重要影响,该性能的高低与包装所处环境息息相关。本文通过控制试验条件进行环境的温度与湿度的模拟,测试在不同试验条件下包装材料的氧气透过量与水蒸气透过率。试验结果显示,随着试验温度、湿度升高,所测试样品的水蒸气透过率、氧气透过量均增加,但增加的幅度并不相同。     

用于食用油的高阻隔抗UV功能的泡罩包装

目的 为开发一种用于食用油的高阻隔抗紫外线(UV)功能片材,用于小容量食用油的泡罩包装,便于携带且方便一次性使用.方法 研究基于高阻隔塑料乙烯-乙烯醇共聚物EVOH,通过多层共挤和多层复合技术,得到一种4层结构的高阻隔片材CPP/APET/PE-EVOH/PE,通过电子万能试验机和气体透过率测定仪对片材的力学性能、水蒸气透过率、氧气透过率进行测定,并通过不同材料对比分析该材料在食用油包装中对食用油货架期的影响.结果 结果表明,片材的力学性能优异,水蒸气透过量为2.0 g/(m2.24 h),氧气透过量为0.6 cm3/(m2·24 h·0.1 MPa).该材料用于食用油包装,在温度45℃、相对湿度50％条件下贮存30d后,橄榄油过氧化值的变化量为1.22 mmol/kg,远低于GB/T 23347-2009《橄榄油、油橄榄果渣油》中特级初榨橄榄油的上限值(10 mmol/kg).结论 该高阻隔抗UV功能的泡罩包装可用于食用油包装,可减缓食用油氧化变质,并保留食用油原有香味.     

PVDC层压复合耐高温蒸煮袋及PVDC五层共挤流延技术的进展

1、关于高阻隔包装材料通常将气体透过量在10cm^3／m^2．24h．atm．50％RH以下的称为高阻隔塑料,目前已经实现工业化生产的高阻隔塑料材料有EVOH、PVDC和PAN三种,投入大规模应用的高阻隔塑料有EVOH、PVDC,尼龙由于其透过性远远高于PVDC和EVOH,因此只能作为中阻隔材料（见表一）。高阻隔包装材料能够防止氧气的侵入使产品氧化变质;防止水或水蒸汽的渗透使商品受潮霉变;防止香气、二氧化碳和异味的透过使商品变味和变质,有效提供保质、保鲜、保风味以及延长产品货架期的保证,在包装工业特别是食品包装工业方面获得了迅速发展和广泛的应用。     

浅谈包装材料的阻隔性与食品品质

正随着经济条件的改善和人们生活品质的提高,消费者对于食品的安全与营养也越来越关注。而大部分食品容易受到环境中的水分、氧气、微生物等的污染而发生品质下降和变质,因此能起到阻隔水蒸气、氧气等的高阻隔食品包装近年来得到飞速发展和广泛应用。本文将从材料阻隔性的产生和影响因素、四大包装材料的阻隔性能、提高阻隔性的措施等方面加以简述,以期为科学合理地选择阻隔性包装材料,提高所包装食品的品质提供指导。一、包装材料的阻隔性包装材料的阻隔性指的是材料阻止小分子透过的性能,     

坚果酸败的包装控制方法

坚果中富含油脂和蛋白质,易在氧气、光照等因素下酸败变质采用合适的包装技术,如高阻隔包装材料、真空包装、充氮包装、添加脱氧剂等,能有效的控制坚果酸败进程。同时,配合专业的包装检测技术加强如氧气透过率、密封性、氮气透过率等重点指标监测,能很大程度上避免保质期内坚果酸败的发生。     

高阻隔性塑料材料在食品包装中的应用

高分子材料的阻隔性是指制品对小分子气体、液体、水蒸气、香味及药味等具有一定屏蔽能力的聚合物材料。如果高分子聚合物的可透性较低,用它对物品进行包装可有效阻隔环境中氧气、水蒸气等的渗入,并保持包装内的特定气体成分,显著提高物品的保质期。目前为满足市场需求,各国相继开发出具有多功能的高阻隔性包装材料,可以延长食品保质期和货架寿命,高阻隔性、多功能性包装材料已成为近几年的发展热点。     

镀铝薄膜正反面阻隔性能变化研究

采用不同材质的三种镀铝薄膜,在相同条件下,分别对三种镀铝薄膜的正反面进行氧气透过量和水蒸气透过量检测.结果表明:镀铝面朝向低压侧时的氧气透过量明显小于镀铝面朝向高压侧时的氧气透过量;镀铝面朝向低湿侧的水蒸气透过量明显小于镀铝面朝向高湿侧的水蒸气透过量.     

真空镀膜在高阻隔性包装材料上的应用

高阻隔性包装材料在食品、饮料、生鲜、药品、电子产品、化工等行业具有广泛的应用。真空镀膜技术生产制备高阻隔陶瓷膜包装材料是近期全球包装材料工业的热点,本文将简要介绍市场上主要的高阻隔性包装膜产品,并对真空镀膜方法生产高阻隔性包装材料的相关工艺技术进行了详细的探讨。     

基于多层涂布工艺的高阻隔透明纸基材料的制备与性能

通过生物基可降解材料制造阻隔性包装的应用越来越受到人们的关注。然而，现有的技术仍较难同时实现纸基包装材料的高氧气阻隔性和水蒸气阻隔性。本研究以自制透明纸作为基底，采用天然高分子材料(淀粉、瓜尔胶)及环保水性防水剂为涂布层，通过涂布工艺制备了兼具高阻氧和阻水蒸气性能的透明纸基材料。结果表明，不同涂层之间充分发挥各自的阻隔作用，降低了外界水蒸气在纸基材料表面的吸附作用，同时增加了水分子和氧气分子在纸张内部的扩散难度；制得的透明纸基材料氧气透过率最低为2.46 cm3/(m2·day·0.1 MPa)，水蒸气透过率仅为107.09 g/(m2·day)，相比于未涂布的透明纸分别下降了92%和94%。同时，有防水层的透明纸基材料的纸与纸板表面吸水量(Cobb)值均小于1 g/m2，接触角大于90°，呈现出良好的疏水性和抗水特性。本文的制备工艺简便、制造成本较低、材料性能可控，有望在替塑包装中得到应用。      

PET/PP药品包装用复合膜高阻隔性能研究

研究了聚酯PET/聚丙烯PP药品包装用复合膜的高阻隔性能,其氧气透过量最低可达0.7cm3/(m2·24h·0.1MPa),水蒸气透过量最低可达1.0g/(m2·24h),通过不同材料阻隔性能的对比及对复合膜红外分析,得出胶粘剂种类和其致密的粘合层结构,可能是材料拥有高阻隔性能的主要原因。     

几种食品包装用塑料膜阻透性能比较

目的研究不同厚度、不同材质的食品包装用塑料膜透氧量、透湿量的变化情况,为食品包装在阻隔性方面的选材提供依据和指导。方法采用压差法和杯式法分别测试塑料膜的透氧量和透湿量。结果单层塑料膜随厚度的增加,透氧量和透湿量均减小,阻隔性能变好。相同厚度的PE,PET,BOPP,PA这4种单层塑料膜中,PA的透氧量最小,PE的透氧量最大,BOPP的透湿量最小,PA的透湿量最大。复合膜厚度增加,其透氧量、透湿量均减小,但减小幅度逐渐变小。塑塑复合膜外层材料厚度不变时,透氧量、透湿量随总厚度变化不太明显,EVOH塑料复合膜的透氧量值和透湿量值较小,通常在5以下,铝箔塑料复合膜的透氧量值和透湿量值均小于1。结论单层塑料膜PA的氧气阻隔性最好,PE的氧气阻隔性最差,BOPP的水蒸气阻隔性最好,PA的水蒸气阻隔性最差。复合膜中,塑塑复合膜的阻隔性主要取决于外层材料,铝塑复合膜的阻隔性最好,含高阻隔材料EVOH的塑料复合膜的阻隔性比普通塑塑复合膜好,其阻隔性可与铝塑复合膜媲美。     

液体农药软包装的研究现状及展望

液体农药因含有毒性较大且腐蚀性较强的甲苯、二甲苯等有机溶剂,其软包装材料应具备较强的耐腐蚀性能和阻隔性能。目前国内市场上液体农药软包装常用的材料主要有PET/Al/CPP(或PE)复合膜、PET/VMPET/CPP(或PE)复合膜、含PA或EVOH的PP,PE多层共挤膜、PET/PVDC(或EVOH)/CPP(或PE)透明复合膜等,常用的胶黏剂为聚氨酯胶黏剂。液体农药包装废弃物的处理一般采取随意丢弃和集中填埋焚烧2种方式,均对环境及人类健康危害较大,必须采取相应的措施以降低其危害。液体农药软包装必须朝绿色环保方向发展,研发并推广可降解材料与水溶性膜。     

Atomic layer deposition on polymer based flexible packaging materials: Growth characteristics and diffusion barrier properties

One of the most promising areas for the industrial application of atomic layer deposition (ALD) is for gas barrier layers on polymers. In this work, a packaging material system with improved diffusion barrier properties has been developed and studied by applying ALD on flexible polymer based packaging materials. Nanometer scale metal oxide films have been applied to polymer-coated papers and their diffusion barrier properties have been studied by means of water vapor and oxygen transmission rates. The materials for the study were constructed in two stages: the paper was firstly extrusion coated with polymer film, which was then followed by the ALD deposition of oxide layer. The polymers used as extrusion coatings were polypropylene, low and high density polyethylene, polylactide and polyethylene terephthalate. Water vapor transmission rates (WVTRs) were measured according to method SCAN-P 22:68 and oxygen transmission rates (O₂TRs) according to a standard ASTM D 3985. According to the results a 10 nm oxide layer already decreased the oxygen transmission by a factor of 10 compared to uncoated material. WVTR with 40 nm ALD layer was better than the level currently required for most common dry flexible packaging applications. When the oxide layer thickness was increased to 100 nm and above, the measured WVTRs were limited by the measurement set up. Using an ALD layer allowed the polymer thickness on flexible packaging materials to be reduced. Once the ALD layer was 40 nm thick, WVTRs and O₂TRs were no longer dependent on polymer layer thickness. Thus, nanometer scale ALD oxide layers have shown their feasibility as high quality diffusion barriers on flexible packaging materials.     

聚乙烯醇基分子筛涂布聚乙烯膜的制备与表征

目的通过调节包装内的湿度,以达到果蔬生长的适宜湿度环境,从而延缓新鲜果蔬的霉变及腐烂速率,延长其保质期,并降低产品损失率。方法将高吸水性树脂PVA与纳米分子筛均匀混合,配制成具有保湿功能的涂布溶胶,采用涂布法将该溶胶与包装基体材料PE相复合,得到一种具有防霉保鲜功能的新型食品包装薄膜。利用电子万能试验机、透氧测试仪、透湿测试仪等仪器测定该复合薄膜的力学性能、阻隔性和透湿性。结果 PVA纳米分子筛/PE复合薄膜在纳米粉体质量分数为1.0%左右时对薄膜物理性能的影响较低,且具有较高的保湿性能,其透气性系数相比未做涂布处理的基材PE大幅降低,透湿量下降20%。结论该复合薄膜在新鲜果蔬的运输、贮存等方面具有潜在的应用价值。     

无菌包装袋的透氧性研究

目的研究无菌包装袋的透氧率与其厚度、材质及温湿度的关系。方法用厚度测试仪测量无菌包装袋厚度,用红外光谱仪检测材质、用氧气渗透测试仪测试透氧率,并比较厚度、材质和温湿度对透氧率的影响。结果无菌包装袋的透氧率随厚度的增加而减小;材质对无菌包装袋的透氧率影响较大;无菌包装袋的透氧率随着温度的增加而增加,阻氧性能下降。结论无菌包装袋的厚度、材质和环境温度对其透氧率均有影响,而相对湿度对透氧率无显著影响。     

增重法与减重法在不同包装材料中的应用

目的探究基于称重法原理的增重法与减重法在不同包材领域内的应用范围。方法避免人工、环境等引入测试误差导致的对比偏差,采用透湿试验腔内自动称量的智能检测仪器,依据ASTM E96标准方法中的增重法与减重法,测试并比较在不同温湿度实验条件下塑料薄膜、纸铝塑复合膜、人造皮革、无纺布等7种不同材质与阻湿性样品的水蒸气透过率。结果纸铝塑复合膜、人造皮革及无纺布样品分别利用增重法和减重法所测得的水蒸气透过率结果有明显差别,而其余4种样品差值不明显;人造皮革样品的增重法实验结果高于减重法的结果,而纸铝塑复合膜及无纺布这2种样品的结果则相反。结论增重法与减重法在测试水蒸气透过率时并非在任何条件下均适用于所有包装材料,应根据样品的材质、结构、使用环境条件及实际用途等因素合理选用增重法或减重法进行检测。     

Thin Laminate Films for Barrier Packaging Application – Influence of Down Gauging and Substrate Surface Properties on the Permeation Properties

A reduction in thickness of barrier laminated film systems generally leads to a quality decrease of the resulting packaging materials' functional properties. Especially for food packaging applications, adequate oxygen and water barrier properties are indispensable. The focus of this study was therefore the development of thin film systems using metallized aluminium or ethyl vinyl alcohol barrier laminates with low oxygen and water vapour transmission properties. Biaxially oriented polyethylene terephthalate and biaxially oriented polypropylene aluminium‐coated thin film laminates as well as corresponding ethyl vinyl alcohol film systems could be successfully produced with oxygen transmission rates of <0.5 cm³(STP)/(m² d bar) and water barrier values of <0.1 g/(m² d). It could be confirmed that the film thickness of these materials within the range of the investigated dimensions does not have an influence on the barrier properties. In fact, the parameters of the production process influence the functional properties of the film systems and must therefore be adapted. Machinability of these excellent thin film systems requires further investigation on packaging lines before they can be transferred to packaging application. Copyright © 2011 John Wiley & Sons, Ltd.     

Effect of high‐pressure food processing on the mass transfer properties of selected packaging materials

The effect of high‐pressure processing (HPP) on the total migration into distilled water and olive oil and on the barrier properties of four complex packaging materials were evaluated. The films were polyethylene/ethylene‐vinyl‐alcohol/polyethylene (PE/EVOH/PE), metallized polyester/polyethylene, polyester/polyethylene (PET/PE), and polypropylene‐SiOx (PPSiOx). Pouches made from these films were filled with food simulants, sealed and then processed at a pressure of 400 MPa for 30 min, at 20 or 60°C. Pouches kept at atmospheric pressure were used as controls. Prior to and after treatment, all films were evaluated for their barrier properties (oxygen transmission rate and water vapour transmission rate) and ‘Total’ migration into the two food simulants. In the case of water as the food stimulant, a low ‘Total’ migration was observed and even a lower one after the HPP treatment. In the case of oil as the food simulant, a higher ‘Total’ migration was found compared to the control as a result of damage to the structures during the HPP treatment. The gas permeability of the films increased after the HPP, compared to the control, due to damages in the structure caused during the treatment. The PET/PE film presented minimum changes in properties after HPP. Copyright © 2010 John Wiley & Sons, Ltd.     

Protecting and preserving clear barrier layers for flexible packaging materials In‐line thermal evaporation of organic topcoat layer

The end market for transparent flexible barrier films is larger than for metallized films. Presently, the market is still dominated by polymeric barrier layers but the used chemicals may be harmful for the environment. An alternative would be transparent thin layers deposited by vacuum deposition techniques using reactive processes. Ceramic materials like silicon oxide or aluminum oxide are used having a film thickness of just ～10 nm, a coating uniformity of +/?5% across and along the film at a barrier performance below 2.0 sccm/m²d for oxygen transmission rate (OTR) and below 1.0 g/m²d for water vapor transmission rate (WVTR) on PET substrates. In this paper, details will be provided about the deposition processes for these barrier layers using thermal evaporation, plasma‐assisted thermal evaporation as well as deposition by electron beam evaporation. An important factor for these high barrier transparent coatings is also to withstand the downstream processes in the whole packaging stream like slitting, lamination, printing etc. One solution is to protect the barrier layers by a Topcoat. For example, off‐line deposition of lacquers is used in field but the market penetration is low due to high process and material costs. An in‐situ Topcoat deposition is a smart solution to overcome this issue saving time and costs. Such an approach will be also described in the presentation and the impact on the performance of the final package will be discussed.