Polystyrene sheet composition and temperature as parameters for migration of styrene monomer into corn oil

Different types of polystyrene used in packaging were tested for styrene monomer migration into corn oil. Several blends of general-purpose polystyrene with different amounts of high-impact polystyrene demonstrated a linear increase of migration of styrene with increasing amount of high-impact polystyrene in the polymer. Faster migration was found for higher exposure temperatures. Migration depended linearly on the content of residual styrene monomer in the polymer.     

Mass transfer from and through packaging materials

The use of polymer films for food packaging requires a knowledge of their transport properties under varying conditions. The permeability to gases and water vapour of the packaging films at the specific conditions of use, i.e. temperature, relative humidity and pressure gradient, are needed for selecting the optimum packaging system to ensure the required shelf-life of the packed product. Migration from, and absorption by, plastic films also play an important role in their selection. The 0₂ and CO₂ permeabilities of three plastic films at four different temperatures were evaluated and shown to follow the Arrhenius relationship in the range tested. The effects of four thicknesses of one film on its permeability are also reported. Three methods to evaluate migration from polymeric films were compared using different weight/volume ratios. The extraction method recommended by the FDA, using n-hexane in a stirred flask, was found to be best. The shelf-life of Matzoth (Jewish Passover bread) packed in polyethylene (stored at 25°C) was found to be longer than the shelf-life of those packed in the higher barrier PVDC/PE. This was apparently due to the absorption of undesirable oxidation compounds, given off from the Matzoth by the PE, which were not absorbed at detectable levels by the PVDC/PE.     

基于包装对物资保障影响性评价体系的研究

评价包装对物资保障影响性时,应将包装融入到整个保障系统中,不能脱离其他分系统孤立的进行.针对我军物资包装和物资保障的实际,提出了建立包装对物资保障的影响性评价体系.     

基于磁芯的环氧树脂基封装材料研究

研究了环氧树脂基封装胶对FeCuNbSiB纳米晶磁芯性能的影响.结果表明,磁芯封装后,磁芯电感值显著下降,在100kHz时电感值下降了10%～45%;封装胶中触变剂、活性填料对磁芯电感值影响非常大,合适的配比有助于封装后磁芯电感值的升高.当触变剂量为60%(占环氧树脂)、活性填料量为100%(占环氧树脂)时,磁芯封装后电感量在100kHz下降9.7%,达到最好水平.     

Influence of packaging material on bread characteristics during ageing

One of the priorities of today's bread‐making industry is to find suitable packaging solutions to satisfy the peculiar requirements of bread, mostly appreciated by Italian consumers for its crispy crust. The packaging material should allow for both rapid heat exchange with the environment and water vapour evaporation to prevent condensation inside the package. Perforated orientated polypropylene (OPP) films are currently the best materials available for satisfying the industry's requirements. Recently, our group demonstrated that bread wrapping with perforated films is efficacious against bread contamination. The aim of this work was to verify whether these types of films could also influence the trend of phenomena related to product ageing. In particular, variations in the moisture inside the loaf during storage and their influence on changes in crumb softness were investigated. Three OPP films and one double‐layer film bag with different hole size characteristics were chosen for this study and their performances were compared with those of a paper bag. Because of the considerable differences in the hole size characteristics, the films showed very different barrier effects to water evaporation. The C250 OPP film (hole mean diameter = 0.54 mm and density = 21.4 holes/cm²) played an interesting role in modulating moisture variations. Wrapping bread in this film enabled both crust crispness and crumb softness to be maintained during 48h of storage. Such performances cannot effectively be obtained by using alternative industrial bread packaging materials, such as paper bags. Copyright © 2006 John Wiley & Sons, Ltd.     

云南传统包装材料的探索

我国正提倡西部经济的开发,而包装对云南经济的发展有极大的促进作用.云南的包装要体现出特色离不开对传统包装材料的探索,多样的材料以及合理化的应用,这些都将为现代包装设计提供重要的借鉴.     

Component migration from adhesives used in paper and paperboard packaging for foodstuffs

This paper presents the first results of research on the migration of adhesive components in the paper and paperboard packaging sector. It examines components that can migrate from a variety of commonly used adhesives in the framework of a ‘worst case’ scenario in respect of the contents. The report also explains the methodology used to analyse extraction and migration and the model used for calculating the transfers. Copyright © 1999 John Wiley & Sons, Ltd.     

军品隐身防护包装材料应用研究

分析了现代战场形势,介绍了国外发展隐身防护包装材料的新进展,从军品包装的角度探讨了我军军品尤其是后勤装备发展隐身防护包装材料应具有防光学、雷达、热红外侦察性能,并应具有良好的环境适应性和操作使用性能.     

The effectiveness of hexamethylenetetramine‐incorporated plastic for the active packaging of foods

The feasibility of LDPE films containing 0.2 or 0.5% (w/w) hexamethylenetetramine (HMT) as antimicrobial packaging material to inhibit microbial growth on the surface of foods was investigated. As HMT is allowed in Europe to be used as a preservative under certain conditions, and as it is mentioned on the list of additives notified to the European Commission as substances which may be used in plastics intended in contact with food products, this compound offers good opportunities for the manufacturing of an antimicrobial packaging material. In a first experiment, fresh orange juice was vacuum packaged in LDPE films containing 0, 0.2 and 0.5% (w/w) HMT and stored at 6°C for 39 days. Every day and later every 3 days, packages of orange juice were analysed for yeasts and lactic acid bacteria. The shelf‐life of orange juice, could not be prolonged significantly by packaging into a 0.2% or 0.5% (w/w) HMT‐containing film. In a second experiment, however, packaging of cooked ham in a 0.5% (w/w) containing LDPE film, significantly affected shelf‐life. After 20 days a significant reduction of total aerobic count and lactic acid bacteria was observed. In an additional migration test, it became clear that the level of HMT released into orange juice was close to the specific migration limit of 15 mg CH₂O/kg imposed by the EC. Copyright © 2000 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.     

Effect of composition on the mechanical properties and water sorption of a butadiene/styrene copolymer-methacrylate monomer soft lining material

A series of experimental soft lining materials has been produced using a butadiene/styrene copolymer with methacrylate monomers, and assessed in terms of their tensile properties. Three different methacrylate monomers, n-hexyl (HMA), ethyl hexyl (EHMA) and 1-tridecyl (TDMA), and two different initiators, benzoyl peroxide (BP) and lauryl peroxide (LP), were used. Other variables were copolymer/monomer ratio and level of cross-linking. Water sorption studies were also carried out on some of the materials, selected in terms of strength, on the pure copolymer (with and without partitioning agent) and on homopolymers of HMA and EHMA. Generally, the EHMA-based materials had the highest strengths and the TDMA the lowest. The highest tensile strength at 11.36±1.80 MPa was produced by the 50/50, LP initiated EHMA material with 1% cross-linking agent, which also had the lowest water uptake. There appeared to be a relationship between tensile strength and water uptake. Water uptake was found to be governed by the partitioning agent in the copolymer powder.     

Postgrouped sampling method of estimation

A postgrouped sampling is considered for estimating the (finite or finite), population mean. Double sampling and an empirical-weighted estimator is used. Unbiasedness, variance and efficiency are considered. Its properties are discussed allowing the simple random sampling with replacement (SRSWR) design in the first phase, and in each stratum for the second phase. It is shown that for a fixed sample size in each postgroup, the variance of the proposed estimator with less prior information is asymptotically equivalent to the usual stratified estimator for fixed allocation. Some examples are provided for natural populations., The method is also extended to simple random sampling without replacement (SRSWOR) design in the first phase, and in each stratum for the second phase. Unbiased variance estimation is provided for both types of sampling designs.     

Migration of alkylbenzenes from packaging into food and Tenax®

Alkylbenzenes (alkyl chain C₁₀–C₁₃) are used as solvent components in certain offset printing inks. Alkylbenzenes were identified from 10 out of 15 samples of offset‐printed food packaging made of board. Printed hamburger collars intended for hamburger restaurants had exceptionally high contents of alkylbenzenes (70–500 mg/kg). Most of the collars had varnish on both the printed surface and the non‐printed food contact surface. Migration of alkylbenzenes from the hamburger collar into a roll was 2 mg/kg. In another test, in which Tenax^® was used as simulant, the effect of a varnish layer on the food contact surface was studied. It was found that the varnish layer reduced migration by about 70%. Tests with Tenax^® as a food simulant resulted in higher migration than in tests with rolls. The European Commission has published a risk assessment report on alkylbenzenes. The report concludes that there is no need for further testing or for risk reduction measures beyond those which are currently applied. However, consumer exposure was calculated without taking into account the possibility of oral exposure to alkylbenzenes migrating from food packagings. The migration of alkylbenzenes thus merits further study. Copyright © 2001 John Wiley & Sons, Ltd.     

双氧水包装桶质检抽样与测试规范

根据双氧水包装技术要求对包装桶制质检抽样与测试方法进行了科学规范     

Evaluation of measures to mitigate mineral oil migration from recycled paper in food packaging

The presence of mineral oil saturated hydrocarbons (MOSH) and aromatic hydrocarbons (MOAH) in food is a safety concern. Migration to food from recycled paper and board is a relevant source of MOSH and MOAH, and the potential of several technologies to reduce it was explored. These technologies were assessed for food safety (people), environment (planet) and economy (profit) in an integrated way, using a framework developed to compare the effect of the technologies with the current state of the art. Two mature technologies were evaluated (MB12 and flotation), two in development (supercritical CO₂ and thermal treatment), and two as a concept (anionic trash catchers and functionalized clays). The use of mineral-oil-free inks for printing newspapers was also evaluated. It was concluded that, although it is desirable to apply mineral-oil-free inks, in the short-term reduction technologies have more impact. All technologies of which the effectiveness could be investigated (MB12, flotation, supercritical CO₂ and thermal treatment) are able to reduce the potential migration of mineral oils by >70%, but none score optimally on all indicators. The MB12 technology shows the best overall performance and is ready for implementation, provided its patent will be available to more parties. Supercritical CO₂ performs best on food safety, but environmental and economic performance has to be improved. The developed assessment framework yields a clear overview of the advantages and disadvantages of the technologies. Based on the assessment, recommendations are made to stakeholders, including the recycling industry, the ink and printing industry, the food industry and research institutes.     

Modified atmosphere packaging of fresh produce using microporous earthenware material

Microporous earthenware sheets of 5.5–5.6mm thickness were fabricated with or without a glazing treatment by passing through a sequential firing procedure in a furnace. Their microstructure and gas permeability against oxygen and carbon dioxide were measured and examined for their usability in modified atmosphere packaging of fresh produce. Compared with plastic packaging materials, earthenware sheets with a high proportion of micropores had very high gas permeability and gave CO₂:O₂ permeability ratios close to 1. Glazing treatment smoothed the surface by clogging the pores on the surface and significantly decreased gas permeability, without affecting the internal microstructure of the earthenware. When the earthenware sheet was combined with a plastic box and used in packaging for strawberries and enoki mushrooms at 5°C, its unique permeability properties developed a modified atmosphere that was beneficial for preserving the quality of the produce. Changes in the earthenware's permeability characteristics due to moisture adsorption and condensation need to be resolved so that the dynamic changes occurring in package atmosphere over time can be better understood. Copyright © 2006 John Wiley & Sons, Ltd.     

LDPE-Ni/多晶铁纤维电磁屏蔽包装材料研究

为制备一种性能优良,使用方便的电磁屏蔽包装材料,用多晶铁纤维和镍粉作为导电填料,填加到LDPE中,制备成了LDPE-Ni/多晶铁纤维电磁屏蔽材料.研究发现,该材料的屏蔽效能值为20dB;"渗滤阈值"为20%～25%;由于多晶铁纤维的复合磁损耗机理,材料的具有一定的吸波功能;当多晶铁纤维和镍粉的含量为18%时,复合材料达到最大拉伸强度12.5MPa,而其断裂伸长率呈下降趋势.     

Effect of processing method on migration of antioxidant from HDPE packaging into a fatty food simulant in terms of crystallinity

Migration of additives from plastic packaging into food products is generally considered to be affected by polymer crystallinity. In the present work, migration of Irganox 1010 from high density polyethylene into a fatty food simulant (ethanol 95%) was studied for samples prepared with different percent crystallinities. For this purpose, 2 different processing techniques, injection and compression molding, were used, and the preparation conditions were changed to obtain high density polyethylene samples with crystallinities in the range of 50 to 70%. Migration analysis was carried out at 121°C for 2 hours, and then at 40°C for 238 hours using high performance liquid chromatography. In general, the injection molded specimens had lower crystallinity and higher overall migration than the compression molded ones. A similar trend for both injection and compression molded samples was observed indicating that the overall migration was a function of crystallinity degree. However, the specific migration rates of Irganox 1010 especially before 50 hours were found to be different for the 2 processing methods because of dissimilar morphologies. Theoretical modeling based on Fickian diffusion was applied to give more insights into the involved processes during specific migration. The interaction of the food simulant with the polymer was taken into account considering the food sorption into the polymer. By fitting the model on experimental data, it was possible to obtain the model parameters such as partition coefficients (K) and the swelling constant (B) as a function of sample crystallinity.     

Sustainability priorities across the strategic and operational level in packaging development

Sustainability is well‐established in many companies' strategic postures. However, executing sustainability‐related goals often lags at the operational level. This study analyses how decision‐making processes in packaging development at different hierarchical levels are characterized in achieving a sustainability consensus. This research focuses on the alignment of the strategic and operational levels of packaging development in relation to the integration of sustainability considerations. This materializes in a stakeholder perspective on packaging development and an analysis of targets aiming for the integration of sustainability considerations in such development processes. The involvement and decision making by internal stakeholders, the involvement of external stakeholders and sustainability target setting are considered as conditions causing the outcome of interest: levels of sustainability implementation on both the strategic and the operational levels of packaging development. By using a set‐theoretic method, we address that different compositions of stakeholder involvement and target setting might cause the same level of sustainability priority at the strategic and operational levels. For data analysis, we use a fuzzy‐set qualitative comparative analysis (fsQCA) with empirical data derived from survey responses by packaging experts. This approach is motivated by its ability to address the complexity of the interplay of case characteristics within development processes. The research findings provide several indications of a limited alignment of a company's strategic sustainability ambition with the operational activities of multidisciplinary packaging development teams. The insights on the sustainability‐related configurations of stakeholders and target setting provide guidance for managing projects across the strategic and operational levels in improving sustainable packaging development.