Wetting properties of food packaging

A top-view vibration system for measuring the apparent contact angle corresponding to the global energy minimum was applied in quantifying the effect of plastic film, roughness, and surface treatment on wettability. Liquids representing typical pure liquids (diiodomethane, ethylene glycol) and food products (10% ethanol, 3% fat milk, 10% sucrose, triolein) were tested on low linear density polyethylene (LLDPE) and polyethylene terephthalate (PET), exposed, or not, to commercial corona discharge treatment (CDT). Apparent contact angle values increased with surface tension of the liquid. The counterpart data derived by the common advancing method were higher, and could lead to erroneous values and misleading interpretations. The major effect of CDT was to enhance surface polarity by significantly increasing the polar component of surface free energy. Interactions between the packaging material and food could have a major effect on product quality, and should therefore be taken into consideration.     

Safety by design of printed multilayer materials intended for food packaging

ABSTRACT

Printing inks are commonly used in multilayer plastics materials used for food packaging, and compounds present in inks can migrate to the food either by diffusion through the multilayers or because of set-off phenomena. To avoid this problem, the right design of the packaging is crucial. This paper studies the safety by design of multilayer materials. First, the migration from four different multilayers manufactured using polyethylene terephthalate (PET), aluminium (Al) and polyethylene (PE) was determined. The structural differences among materials such as the presence of inks or lacquer coatings as well as the differences in layers position allowed the study of a safety-by-design approach. Sixty-nine different compounds were detected and identified; 49 of them were not included in the positive list of Regulation EU/10/2011 or in Swiss legislation and 15 belong to Cramer class III, which means that they have a theoretical high toxicity. Some of the compounds related to ink composition were pyrene, a compound commercially used to make dyes and dye precursors and the antioxidant Irganox 1300. The application of external lacquers decreased the concentration of some migrants but also brought the potential for new migrants coming from its composition. A final risk assessment of the material allowed evaluating food safety for different food simulants and confirm it.     

Life Cycle Assessment of multilayer polymer film used on food packaging field

The environmental impact of a multilayer polymer film, Low Density Poly Ethylene/Polyamide system (LDPE/PA), generally used on food packaging field, was estimated using life cycle assessment (LCA). The aim of the work was to understand how to reduce the environmental pressure from plastic packages for its lower recovery and reuse, which can be improved by developing material recovery or other appropriate recycling technology to improve the cyclic materials flows and recycling ratio. LCA is a tool specifically developed for assessing the overall environmental burden of a product, including the system used for manufacturing it and its end-of-life treatment. This work provides a cradle-to-grave LCA study of a food packaging envelope made with a multilayer polymer film, with two different depth of 70 and 90 micron, and a study of the possibility to utilize a 50% of recycled LDPE and PA polymer pellets in order to reduce the environmental impact. A one square meter envelope is used as functional unit.     

Overall migration from commercial coextruded food packaging multilayer films and plastics containers into official EU food simulants

The overall migration from a wide range of commercial five-layer coextruded packaging films into aqueous food simulants (distilled water, 3% aqueous acetic acid) and alternative fatty food simulant (iso-octane) was studied. The overall migration from commercial plastics cups (PS, HIPS, and PP) used for ice-cream or yogurt packaging into distilled water and 3% aqueous acetic acid was also studied. Test conditions for packaging material/food simulant contact and method of overall migration analysis were according to the EU directives and CEN-standards. The results showed that for all tested five-layer films and plastics (PS, HIPS, and PP) cups values of overall migration into aqueous simulants (0.11-0.79 mg/dm², 2.3-15.9 mg/l) and (<0.10-0.41 mg/dm², <0.80-3.1 mg/l) were significantly lower than the upper limit (10 mg/dm²) for overall migration from plastic packaging materials and articles into food and food simulants set by the EU Directive 90/128/EEC and their revisions. The overall migration values from five-layer materials into iso-octane were significantly higher (0.94-8.23 mg/dm², 18.8-164.7 mg/l) than the above values but are still lower than the upper limit for overall migration. Global migration values of five-layer films into aqueous food simulants seems to be independent of material thickness. In contrast, overall migration into iso-octane increases with film thickness.     

Experimental and theoretical study of LDPE: Evaluation of different food simulants and temperatures

The mass transfer process of additives from plastic packaging to food is of great importance and interest because of the possible harmful effects on the human health. In this work the effect of different food simulants (EtOH 10–50%) and temperatures (28–60 °C) on the specific migration of Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (I-1076) from LDPE films is experimentally and theoretically studied, considering also the antioxidant stability in the food simulants studied at different temperatures.On the other hand, a phenomenological model based on a resistances-in-series which was resolved through the Regula Falsi algorithm according to a routine that considers the income of the structural parameters of the system and experimental conditions in which migration testing was performed. Diffusion coefficients of I-1076 in LDPE were ranged between 8.0E10–14 and 1.2E10–12 (m² s^{− 1}) for temperatures of 28 to 60 °C, respectively. The coupled effect of mass transfer and thermodynamical aspects was analyzed through the parameter Bi/K_P/FS proposed in this work, estimated in order to identify the combined contribution of the transport rate and the availability of the migrant compound in the food phase.     

Development of mono and multilayer antimicrobial food packaging materials for controlled release of potassium sorbate

In this study, cellulose acetate (CA) based mono and multilayer films including potassium sorbate (Psb) as an antimicrobial agent were prepared using dry phase inversion technique. To achieve appropriate controlled release of Psb, the structure of the films was changed by manipulating the film preparation conditions. In particular, the initial casting composition, wet casting thickness and drying temperature were varied. Results indicate that Psb release rate decreased as the CA content in the casting solution, the wet casting thickness and the drying temperature for both mono and multilayer films were increased. Compared to the results for the monolayer films, a significant decrease of Psb release rate through the multilayer films was recorded. Drying-induced crystallization was observed in the monolayer films. As a consequence of this, a fast initial release of Psb, controlled by Fickian diffusion, was followed by a slower release controlled by dissolution of Psb crystals. In multilayer films, no crystals were detected in the structure and the release rate was regulated only by diffusion of Psb through the film. The results suggest that the films prepared in this study can be used as food packaging materials for achieving controlled and extended release of Psb.     

食品包装塑料薄膜的机械性能及检测方法研究

柔软的塑料薄膜适用于各种各样的包装,食品包装材料的机械性能是产品在包装之后对产品进行保护的最基本性能,可以防止包装的破损与泄漏。本文阐述了食品包装塑料薄膜的主要机械性能,包括拉伸性能、剥离性能、热合性能、撕裂性能、冲击性能以及穿刺性能,并介绍了主要的食品包装塑料薄膜的机械性能检测方法,为食品包装技术的研究和新产品的开发提供参考。     

Environmental assessment of a multilayer polymer bag for food packaging and preservation: An LCA approach

A screening of LCA for the evaluation of the damage arising from the life cycle of a bi-layer film bag for food packaging was carried out. Such packages are made of films obtained matching a layer of PA (Polyamide) with one of LDPE (Low-Density Polyethylene) and are mainly used for vacuum or modified atmosphere packaging and preservation of food. The study was conducted in accordance with the ISO standards 14040:2006 and 14044:2006 choosing, as the functional unit, 1 m² of plastic film delivered to the food production and packaging firms. The system boundaries go from cradle to factory-gate and include the phases of: the raw materials production and processing for the bag manufacturing; and the bag delivering to the food production and packaging plant.The damage assessment showed that the most impacting phases are the production of the Polyamide (PA6) and Low-Density Polyethylene (LDPE) granules due to the consumption of primary resources, such as natural gas and crude oil, in the amount of 53.55 dm³ and 132.42 g respectively, and to the emission in air of 295.73 g of carbon dioxide, 617 mg of nitrogen oxides, 12.1 mg of particulates, 349 mg of sulphur dioxide and 2.51 mg of aromatic hydrocarbons. The most affected damage category is Resources, followed by Climate Change, Human Health, and Ecosystem Quality.For minimising the total damage associated with the life cycle of the examined bag, the film thickness thinning and the use of a recycled PA granule were considered: the assessment showed that the two proposals allowed a reduction of about 25% and 15% (respectively) of the damage assessed.     

Preparation and properties of polypropylene/clay nanocomposites for food packaging

Polypropylene (PP)/clay nanocomposites based on PP, organic clay (montmorillonite; MMT), and maleated polypropylene (MAPP) were prepared by melt compounding. The mechanical, thermal, morphological, and gas barrier properties of the resulting PP/clay nanocomposites were investigated at varying concentrations of the components for food packaging. The results revealed that the mechanical strengths, including tensile, flexural, and Izod impact strength, were increased for PP/clay nanocomposites compared to neat PP. The thermal properties showed a tendency for the melting and degradation temperatures to increase with the clay concentration. The effect of the compatibilizer was observed using scanning electron microscopy (SEM). The X-ray diffraction pattern of the nanocomposites revealed increased d-spacing of the MMT layers, indicating that the compatibility of neat PP and clay was improved by the addition of MAPP, and the intercalation and partial exfoliation of the layers. The use of clay increased the mobility distance of the gas molecules, leading to the oxygen permeability of neat PP being reduced by 26% to 55%.     

Development of antioxidant food packaging materials with controlled release properties

In this study, cellulose acetate (CA) films with different morphological features were prepared in order to control the release rates of low molecular weight natural antioxidants, L-ascorbic acid and L-tyrosine. Increasing CA content in the casting solution decreased the average pore size and porosity of the films, thus, reduced the diffusion rates of both antioxidants through the films. Although both antioxidants have similar molecular weights, L-tyrosine released into water much more slowly than L-ascorbic acid. The highest antioxidant activity in release test solutions was observed with highly porous L-tyrosine containing films. However, when the porosity of the films reduced, the antioxidant activity of L-ascorbic acid released into solution was found to be higher due to trapping of significant amount of L-tyrosine in dense films. The use of different antioxidants caused different changes in morphological and mechanical properties of the CA films. Varying the structural features of the films with the preparation conditions or using different surfaces of the films allowed the controlled release of each antioxidant.     

浅述国外食品包装安全体系

欧美发达国家特别是美国和法国十分重视包装安全工作，也是世界上包装安全法规，安全体系最完善的国家。无论是军品弹药包装，危险化学品包装，还是食品安全包装，都有系统的安全法规，完善的管理体系，以及安全行动计划。[编者按]     

Migration from printing inks in multilayer food packaging materials by GC-MS analysis and pattern recognition with chemometrics

Inks and varnishes used in food packaging multilayer materials can contain different substances that are potential migrants when packaging is in contact with food. Although printing inks are applied on the external layer, they can migrate due to set-off phenomena. In order to assess food safety, migration tests were performed from two materials sets: set A based on paper and set B based on PET; both contained inks. Migration was performed to four food simulants (EtOH 50%, isooctane, EtOH 95% and Tenax^®) and the volatile compounds profile was analysed by GC-MS. The effect of presence/absence of inks and varnishes and also their position in the material was studied. A total of 149 volatile compounds were found in migration from set A and 156 from set B materials, some of them came from inks. Quantitative analysis and a principal component analysis were performed in order to identify patterns among sample groups.     

食品的绿色包装

绿色设计早已不是一个新鲜概念了,而绿色从某种意义上来讲又是现代人类文明的一个重要标志.人们现在习惯把生活中的各种事物都与绿色联系在一起,绿色生活新概念也成为了国际上的热点内容.     

食品包装的标准化与规范化

随着全球经济一体化进程的加快和我国加入WTO,标准化工作的地位和作用日渐突出,我国也一向重视标准化的问题,早在1988年12月29日中华人民共和国第七届全国人民代表大会常务委员会第五次会议上就通过了<中华人民共和国标准化法>,并于1989年4月1日起实施,国家技术监督局于同一天作出了<中华人民共和国标准化法条文解释>,中华人民共和国国务院1990.04.06发布<中华人民共和国标准化法实施条例>,此后各行政主管部门也积极制定了一系列标准化方面的法律法规.     

Styrene polymers and food packaging

Polymers based on styrene monomer can be produced with a wide range of properties by co-polymerisation and the incorporation of rubber impact improvers. In some areas of food applications, polystyrene is under strong competition from polypropylene—the price is obviously an important factor.For margarine packaging, thermoformed tubs based on acrylonitrile-butadiene-styrene still dominate the market.The usual considerations of possible toxic hazard by migration of low molecular components of the polymers apply; the two most likely materials which will be in the polymers are styrene with ethylbenzene and acrylonitrile. Styrene is now considered to be fairly safe and the organoleptic effect is the controlling factor: acrylonitrile presents a more serious problem and is under very critical study—it is necessary to impose strict limits on migration into the food.     

Application of Finite Element Analysis (FEA) for the simulation of release of additives from multilayer polymeric packaging structures

Computer programmes are available to predict, for consumer protection purposes, the migration of additives from a polymeric package during its contact with food. However most of these programs were developed to estimate migration only from single layer polymeric packaging under isothermal conditions. In this work a diffusion model was developed to simulate the migration from multilayer packaging and under non-isothermal temperature conditions, too. Finite Element Analysis (FEA) is used as a numerical approximation method to solve the diffusion equations describing such processes. The possibilities and limitations of the FEA method are presented and the correlation between experimental and computed results is discussed.     

天然包装材料在食品包装设计中的应用

针对塑料、纸质、金属等食品包装材料各自的弊端和问题,阐述了食品包装材料减量化、单一化、轻型化、无毒无害化发展趋势,指出天然包装材料在食品包装中的应用范围及性能,揭示了天然包装材料的审美价值,提出了天然包装材料的选用原则和应用原则。