单一材质可回收高阻隔耐穿刺软包装的研究

本文以双向拉伸聚乙烯(BOPE)薄膜、多层共挤高阻隔聚乙烯吹塑(MTPE)薄膜作为复合材料,运用万能力学测试仪、氧气透过量测试仪等表征技术,系统研究了BOPE/MTPE复合膜的力学性能、阻隔性能。研究发现,BOPE薄膜具有优异的耐针孔穿刺等力学性能;高阻隔材料显著提高了MTPE的阻隔气体性能。BOPE薄膜及CPE薄膜材料同质,利于回收循环再利用,符合环保趋势。     

材质一体化可回收高阻隔复合软包装的研究

本文以双向拉伸聚乙烯(BOPE)薄膜、多层共挤流延聚乙烯(CPE)薄膜作为复合材料,以聚乙烯醇(PVA)复配水性胶水作为阻隔胶粘材料,运用万能力学测试仪、扫描电子显微镜、氧气透过量测试仪、水蒸气透过量测试仪等表征技术,系统研究了BOPE/PVA阻隔水性胶水/CPE复合膜的力学性能、阻隔性能、热封性能。研究发现,BOPE薄膜具有优异的力学性能;CPE薄膜具有优异的热封性能;PVA复配水性胶水显著提高了复合膜的阻隔气体性能。BOPE薄膜及CPE薄膜材料同质,利于回收循环再利用,符合环保趋势。     

双向拉伸聚乙烯薄膜产业化发展现状与瓶颈及展望

随着高分子合成技术和加工设备技术的发展,平膜法生产双向拉伸聚乙烯(BOPE)薄膜得以实现。由于其优异的综合性能和环保优势,BOPE薄膜具有广阔的市场前景。文中从原料、设备、技术和经济、社会发展等几个方面综述了BOPE薄膜产业化的现状、瓶颈与机会。随着科学技术的进步和环保政策的落实,BOPE薄膜有望在近期成为继双向拉伸聚丙烯(BOPP)薄膜、双向拉伸聚对苯二甲酸乙二醇酯(BOPET)薄膜、双向拉伸聚苯乙烯(BOPS)薄膜等之后的又一个双向拉伸薄膜技术产业化的典范。     

国际要闻

日本东燃石化公司开发成功BOPE薄膜 随着塑料加工工业的迅猛发展,日本东燃石化公司首次开发成功双向拉伸聚乙烯薄膜。这是世界上继双向拉伸聚丙烯薄膜开发成功之后的又一重大成果。它的综合性能优于双向拉伸聚丙烯薄膜,其特点是透明度高,纵、横向抗拉强度好,并具有防湿和可折迭性,可与各种材料进行湿法复合,并能在低温状态下进     

八方信息

新颖的BOPE薄膜 随着塑料加工工业的迅猛发展,日本的东燃石化公司首次开发成功双向拉伸高密度聚乙烯薄膜。这是世界上继双向拉伸高密度聚丙烯薄膜开发成功之后的又一重大成果。它的综合性能优于双向拉伸高密度聚丙烯薄膜,其特点是透明度高,纵、横向抗拉强度好,并具有防湿和可折迭性,可与各种材料进行湿法复合,并能在低温状态下进行热封。双向拉伸高密度聚乙烯薄膜光泽度高,可进行扭     

国内包装期刊文摘

前言：国内出版的各种包装刊物中．发表了不少有关塑料包装的文章。为了供塑料包装行业科技及管理人员的参考。特陆续收集并编成文摘．以广交流。塑料编织袋内衬薄膜破损原因剖析／张宏强（河南进出口商品检验局），仲国包装工业））95—2，PIS。本文介绍了内衬薄膜五种破损原因。多层共挤薄膜的发展趋势／韩衍（山东塑料试验厂）《中国包装工业）．95一2，P19。本文叙述多层共挤薄膜技术，层间粘合以及多层共挤膜的发展趋势。双轴定向拉伸聚酯薄膜技术浅谈／陈韵诗（南京塑料包装材料总厂）《中国包装工业》，95一3‘P12。本文介绍BOPE…     

高档次多层共挤流涎机控制系统

多层复合薄膜的加工方法很多，归纳起来主要有涂布法、层压法和共挤法三种。涂布法和层压法的复合工艺基本上有些相似，简单地讲就是用粘结剂使一层薄膜与另一层基材(即薄膜、纸张或金属箔等)结合，或多层薄膜与基材结合起来。而共挤法则是近年来刚刚发展起来的一种较新的多层复合薄膜加工方法。这种方法是将多种聚合物熔体由一个特殊模头汇集在一起，成为由多层不同聚合物熔体构成的薄膜状熔体流，经冷却而得到多层共挤出复合薄膜。     

多层共挤复合热封材料的应用

在干式复合和挤出复合等复合薄膜中，用多层共挤复合薄膜替代普通单层薄膜作为热封基材在生产成本、加工性能和材料性能上具有明显的优势。多层共挤复合薄膜将成为一种新型的热封基材被越来越多的生产厂家和用户所接受。     

多层共挤复合热封材料的应用

在干式复合和挤出复合等复合薄膜中，用多层共挤复从事 薄膜替代普通单层薄膜作为热封基材在生产成本、加工性能和材料性能上具有明显的优势，多层共挤复合薄膜将成为一种新型的热封基材被越来越多的生产厂家和用户所接受。     

四趋势引领我国纸箱包装机械发展

日前。申达集团常州钟恒功能性环保节能型BOPET新材料项目举行竣工典礼，标志着当今世界水平最先进、规模最大的“三层共挤、双向拉伸聚脂薄膜”生产线正式投产。     

Microperforation of Three Common Plastic Films by Laser and Their Enhanced Oxygen Transmission for Fresh Produce Packaging

Three different plastic films of biaxially oriented polypropylene (BOPP), biaxially oriented polyethylene terephthalate (BOPET) and low‐density polyethylene (LDPE) were perforated using Nd‐YAG laser. Effects of laser pulse energy were examined by varying energies from 50 to 250 mJ where the pulse duration and pulse repetition were kept constant at 10 ns and 1 Hz, respectively. It was found that perforation diameters of all films increased with increasing pulse energies. Observed perforations were different among the three film types. Explanation was contributed to material inherent property and its interaction with laser. Incorporation of an inorganic filler (i.e. silica based anti‐blocking agent used in packaging film) of 0.5 wt% into the LDPE films (0.5Si‐LDPE) could improve perforation performance for LDPE. This was attributed to an increased thermal diffusivity of the 0.5Si‐LDPE film. Commercial BOPET and BOPP films containing 97 microholes/m² (hole diameter of ~100 µm) showed an improvement in oxygen transmission rates (OTR) of 18 and 5 times that of the neat films without perforation. In the case of perforated 0.5Si‐LDPE films having similar perforations of 97 microholes/m² and perforation diameter of 100 µm, a two‐fold increase of OTR was obtained. Gas transmission rates of the microperforated films were measured based on the static method. Measured OTR and CO₂TR values of the three films with varying perforation diameters in a range of ~40–300 µm were compared and discussed. Overall results clearly indicate that perforation by laser is an effective process in developing breathable films with tailored oxygen transmission property for fresh produce packaging. Copyright © 2014 John Wiley & Sons, Ltd.     

Development of attenuated total reflection based compression modulation step-scan Fourier transform infrared spectroscopy and its applications to rheo-spectral characterizations of polymer films

Dynamic compression modulation attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopic methods have been developed in this paper for characterizing polymer films. To obtain dynamic compression polarized ATR spectra, internal reflection element (IRE) secure assemblies made of tungsten carbide with very high hardness (Knoop hardness of > 1000 kgf/mm(2)) have been designed. These assemblies are mounted on the Harrick Seagull ATR attachment and measured by step-scan FT-IR spectroscopy. The effect of static compression, air gaps, and refractive index changes were examined. Experimental and simulated results showed that the effect of air gaps between the sample and IRE and refractive index changes of the sample and IRE are negligible at values larger than a static torque of 40 cN m and good signal-to-noise ratios (SNR) and reproducible data can be obtained. Uniaxially and biaxially drawn poly(ethylene terephthalate) films were measured by the presented method. Both bipolar and unipolar bands were observed in the dynamic in-phase ATR spectra, which can be associated with their micro-structural environmental changes. This technique shows promise in evaluating various polymer film materials, including biaxially oriented films, multilayer coated film surfaces, and molecular interactions between polymer-polymer and polymer-additives at the film surface.     

Impact of Production and Conversion Processes on the Carbon Footprint of Flexible Plastic Films

The present study aimed to identify and compare the carbon footprint associated with polyolefin films (linear low‐density polyethylene, high‐density polyethylene and polypropylene), with the idea of developing a simple and affordable empirical method to assist the flexible packaging industry, notably small and medium‐sized enterprises, in estimating the carbon footprint of different products or of new products at the early stage of development. It was found that the total global warming potential (GWP) of the studied films increased 19–67% during processing when compared with the GWP embodied in plastic resins. This indicated that film production processes greatly contribute to the carbon footprint of plastic films. The relative impact of the film‐making process on the total GWP of films is largely a function of plastic type, in particular, its melting point. Printing and lamination processes also contribute significantly to the total GWP of films, with the major factor being electricity use. The constant k was derived to indicate the influences of plastic types and manufacturing processes on the total GWP of films and to help calculate the carbon footprint of polyolefin films for which the production process and weight are known. Moreover, the GWP of each studied film was normalized with respect to film thickness and area. This information would be useful for packaging manufacturers and users to calculate the carbon footprint of multilayer films. The proposed empirical model showed satisfactory results, as the difference was less than 10% when compared with the results obtained from life cycle assessment studies. Copyright © 2014 John Wiley & Sons, Ltd.     

Mineral Oil Barrier Testing of Cellulose‐Based and Polypropylene‐Based Films

Recycled cardboard has been identified as a major source of mineral oil hydrocarbon (MOH) contamination of foods. Identifying and using appropriate functional barriers is a mechanism through which this problem can be addressed. A number of cellulose‐based and biaxially oriented polypropylene (BOPP) films were evaluated as potential functional MOH barriers. The films were tested using a donor material, a paper containing MOH placed on one side of the film barrier and a paper which acted as the receptor on the other. Testing was performed at accelerated conditions of 60°C, the receptor analysed periodically for MOH. The results demonstrated that the cellulose‐based film types provided an MOH barrier of >3.5 years. This contrasted with the BOPP selected films, for which only the proprietary acrylic‐coated BOPP film provided an effective barrier to MOH migration. Further investigation of the MOH barrier properties of the proprietary acrylic‐coated BOPP film was undertaken. Various coating strategies were employed including increasing the coating application weight, increasing the number of coating lay downs and coating one or both surfaces of the film. It was found that an MOH barrier of 1.5 years when tested at 40°C could be achieved for the proprietary acrylic‐coated BOPP film; however, barrier effectiveness was dependent on the coating integrity of the film. Further work with a vertical form filler packaging machine and the use of a staining technique with transmission microscopy proved effective at highlighting and assessing the coating integrity of packets during a typical packaging operation. Copyright © 2014 John Wiley & Sons, Ltd.     

Development of an identification system for biaxially oriented polymer films based on the degree of their transverse extension

An expression has been developed that generalizes three basic geometric schemes of film deformation (axial, planar, and biaxial extension) and also all intermediate schemes. The system of quantitative identification of nonuniformly biaxially oriented films according to their transverse extension has been tested on six different film types.     

Elevated temperature nanoindentation and viscoelastic behaviour of thin poly(ethylene terephthalate) films

A commercial nanoindentation system fitted with a heating stage and heated indenter has been used to investigate how the elevated temperature nanoscale mechanical properties of poly(ethylene terephthalate) films vary with their processing history and crystallinity over the temperature range 60-110 degrees C. Three additive-free thin films were tested; an undrawn amorphous film, a uniaxially drawn film, and a commercial biaxially drawn Melinex film. A sharp decrease in mechanical properties was observed between 70 and 80 degrees C on the undrawn and uniaxial film consistent with the presence of a glass transition over this temperature range in agreement with literature values for bulk materials. In contrast, a gradual decrease in properties was observed over the same temperature range on the biaxially oriented film. The high crystallinity of the biaxial film could be beneficial in extending the operating temperature of the film. There is a minimum in the elastic recovery parameter around 80 degrees C on both the amorphous and biaxial film. This indicates that the elastic recovery parameter may be more sensitive to changes in mechanical properties occurring at/near the glass transition region than the hardness or modulus alone. A recently introduced dimensionless parameter for creep, A/d(0), was also found to be a promising way to characterise the increased time-dependent deformation around the glass transition region.     

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.     

Porous Ultrahigh Gas‐Permeable Polypropylene Film and Application in Controlling In‐pack Atmosphere for Asparagus

Porous polypropylene (PP) films with greater gas permeability and lower permeability ratios (β) than existing commercial films were developed for fresh produce packaging. PP containing high content of beta‐form crystal was biaxially stretched under controlled conditions. Resulting porous films with uniquely high oxygen transmission rate (OTR) of 2 659 000 cm³?m^?2?d^?1, water vapor transmission rate of 67 g?m^?2?d^?1, and β value of 0.76 was used as a “breathable window” attached to the less permeable commercial BOPP (biaxially oriented PP) lidding film. Various sizes/areas of the breathable windows were designed and tested on packaging asparagus of 400 g, at 5°C. Results demonstrated that in‐pack O₂ and CO₂ concentrations could be practically controlled and modified by changing areas of the breathable windows. Altered porous high OTR area directly affected total gas permeation of the package. Optimum gas composition of Ο₂ and CΟ₂ within the recommended controlled atmosphere for asparagus, stored at 5°C, was effectively created and maintained in the package containing 25 cm² breathable window (15% of total film lid's area). The shelf life of asparagus under optimum modified atmosphere was extended to 29 days, as compared with <3 days in the normal, low OTR tray sealed with BOPP lidding film. Clearly, these developed porous ultrahigh permeable PP films can be useful materials in designing high OTR package with desirable in‐pack O₂ and CO₂ concentrations. Copyright © 2013 John Wiley & Sons, Ltd.     

果蔬保鲜膜的研究进展

果蔬保鲜应控制包装储存环境中O_2和CO_2的体积比,控制储存环境的相对湿度,及时排除果蔬在包装存储中释放的乙烯、乙醇等气体。果蔬保鲜膜主要有普通保鲜膜、微孔保鲜膜、防雾功能保鲜膜、可食性保鲜膜、硅窗调气保鲜膜和抗菌保鲜膜等。在果蔬保鲜的实际应用中,一般采用复合式保鲜法。多功能保鲜膜及可降解的无公害保鲜膜将是今后果蔬保鲜膜的发展趋势。     

The Influence of High Pressure Treatment and Thermal Pasteurization on the Surface of Polymeric Packaging Films

Several common single layer films (PE‐HD, PE‐LD, PP‐BO, PA6‐BO and PET‐BO) and multilayer (PS/PE, PP‐BO/PEpeel and PET‐BO/PE) films were treated by either high pressure (600 MPa) or temperature (80 °C/90 °C) to simulate a high pressure or thermal pasteurization process. The samples were tested by atomic force microscopy (AFM), profile method and surface energy measurements to obtain information about the influence of the treatments on the surface topography and surface energy of the samples and by differential scanning calorimetry and by tensile testing concerning material properties. As key figures arithmetic surface roughness (by AFM at Pulsed Force Mode and profile method), surface energy by surface energy measurement and adhesion between tip and surface by AFM were extracted. Results indicate an influence of both high‐pressure processing and thermal‐processing on the surface roughness of biaxial oriented polymer films as single layer films. Laminated biaxially oriented polymer films showed no changes regardless of which processing was performed. The surface energy was hardly affected by both of the treatments for any stretched, non‐stretched, single or laminated films.