基于生产周期的包装印刷品碳足迹测算方法研究

目的 对包装印刷品的生产周期碳足迹核算流程、核算方法、数据收集等方面进行探讨，归纳出包装印刷品生产周期碳足迹测算中存在的问题，并提出解决测量问题和降低生产周期碳足迹的可行策略和建议，为国内外包装印刷企业产品碳足迹测算和“碳中和”提供参考。方法 结合包装印刷企业实际生产数据和印刷品碳足迹国际核算标准，以化妆品包装盒为例进行碳足迹现场测算研究。结果 从工艺角度看，包装印刷品生产周期碳足迹绝大部分来源于造纸、印刷、覆膜生产过程，其次是糊盒、上光等印后加工过程，从原辅材料和能源角度看，碳足迹绝大部分来源于纸张、电力、胶水。结论 对生产设备进行节能降耗、选择低碳原辅材料代替高碳原辅材料和创新产品结构设计将是降低包装印刷品生产周期碳足迹的有效措施。     

Polymeric packaging film for food products

The object of this paper is to report the development and testing of a new packaging film that increases the storage term of food and agricultural products, expands the functional possibilities of film packaging and improves product quality. To achieve this, the polyolefin polymeric packaging film is produced with a structure varying across its thickness with a density gradient ranging from ½p to ¼p, where p is the density of the polyolefin. The packaging film is a system in which the communicating pores are filled with specific additives in a liquid phase.     

Fabrication and Properties of Antioxidant Polyethylene‐based Films Containing Marigold (Tagetes erecta) Extract and Application on Soybean Oil Stability

Four films were extruded in a pilot‐plant scale blown extrusion machine: a monolayer low‐density polyethylene (LDPE) film added with 2.90% of marigold (Tagetes erecta) extract, a two‐layer high‐density polyethylene/LDPE film added with 3.59% of the extract in the LDPE layer and the corresponding two control films without addition of the extract. More than 64% of astaxanthin contained in the extract was lost during the extrusion process. Spectroscopic, optical and mechanical properties of the films were affected by the addition of the marigold extract. The films showed to be light sensitive when exposed to commercial light at 25 °C; however, bags made of the films showed a positive effect on soybean oil stability when used as packaging. Copyright © 2012 John Wiley & Sons, Ltd.     

Evaluation of a bio‐coating as a solution to improve barrier,friction and optical properties of plastic films

The present research dealt with evaluating barrier, friction and optical properties of three different plastic films after deposition of a gelatin‐based bio‐coating. The composite films showed improved barrier properties against oxygen and UV radiation. The oxygen transmission rate decreased in the order of 73% for oriented polypropylene (OPP), 56% for low‐density polyethylene (LDPE) and 40% for polyethylene terephthalate (PET). The increased UV barrier characteristics ranged from 20% for OPP to 12% for both LDPE and PET. Static and kinetic coefficients of friction significantly decreased both in the film‐to‐film and in the film‐to‐metal tests, leading to a desirable value for many applications. However, bio‐coated films showed lower optical performances in terms of transparency and haze. Transparency decreased mainly for LDPE (36%), whereas the haze index increased especially for OPP (85%). Non‐significant differences were observed as far as the water vapour permeability was concerned, except for a slight reduction for PET (from 15.78 to 13.53 cm³/m²/day at 23°C and 90% of relative humidity), suggesting that non‐meaningful effects arose from the addition of a hydrophobic component in the original formulation. Finally, the solubility of the coating in water was around 25% for all the three plastic substrates. The obtained data suggest that the lipid protein coating tested in this study, in spite of its great potential for enhancing some characteristics of plastic packaging films, still exhibits negative aspects which necessitate further improvement. Copyright © 2008 John Wiley & Sons, Ltd.     

Whey protein isolate coating on LDPE film as a novel oxygen barrier in the composite structure

To examine the feasibility of whey protein isolate (WPI) coating as an alternative oxygen barrier for food packaging, heat‐denatured aqueous solutions of WPI with various levels of glycerol as a plasticizer were applied on corona‐discharge‐treated low‐density polyethylene (LDPE) films. The resulting WPI‐coated LDPE films showed good appearance, flexibility and adhesion between the coating and the base film, when an appropriate amount of plasticizer was added to the coating formulations. WPI‐coated LDPE films showed significant decrease in oxygen permeability (OP) at low to intermediate relative humidity, with an Arrhenius behaviour and an activation energy of 50.26 kJ/mol. The OP of the coated films increased significantly with increasing relative humidity, showing an exponential function. Although the coated films showed a tendency to have less oxygen barrier and more glossy surfaces with increasing plasticizer content, differences in the OP and gloss values were not significant. Haze index and colour of the coated films were also little influenced by WPI coating and plasticizer content. The results suggest that whey protein isolate coating could work successfully as an oxygen barrier and have potential for replacing synthetic plastic oxygen‐barrier layers in many laminated food packaging structures. Copyright © 2004 John Wiley & Sons, Ltd.     

Synthesis,Characterization and O2 Permeability of Shape Memory Polyurethane Films for Fresh Produce Packaging

The aim of this work was to investigate the effect of film formulations in an effort to obtain a fresh produce packaging film with increased temperature sensitivity for gas permeability. Series of shape‐memory polyurethane (SMPU) were synthesized using poly(ethylene glycol) (PEG), 1,6‐hexamethylene diisocyanate, 1,4‐butanediol and castor oil (CO) and casted into films. The changes in thermal, viscoelastic, shape‐memory properties and oxygen permeability of the films were studied. The polyurethane films with 1500 g mol^?1 PEG showed a phase transition temperature (switching temperature) between 20 and 27°C. The SMPU consisting of 50/50 CO/PEG had a log E′ value of 8.32 Pa and showed good elasticity as low density polyethylene. SMPU prepared from 1500 g mol^?1 PEG with 50/50 CO/PEG and 40/60 butanediol/(PEG + CO) ratios showed excellent shape‐memory properties with shape recovery ratio >85% and shape fixity ratio >90%. This film had higher oxygen permeability and showed up to 67% increase in Q₁₀ value for oxygen permeability compared with commercial packaging films like low density polyethylene. This film can be used to develop smart packaging with increased thermally responsive gas permeability to similar levels observed in respiration rates of fresh produce. Copyright © 2016 John Wiley & Sons, Ltd.     

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.     

塑料包装废弃物的化学回收技术研究进展

目的 以聚烯烃和聚对苯二甲酸乙二醇酯(PET)为研究对象综述近5年来塑料包装废弃物的化学回收技术,以期为塑料包装废弃物的资源化技术发展趋势提供参考。方法 通过收集与整理相关文献,阐述聚烯烃类以及PET包装废弃物的化学回收方法、常用催化剂、反应装置等,分析催化剂、反应装置、反应温度等条件对产物收率、成分的影响。结论 未来短期内柔性包装材料仍然会以聚烯烃、聚酯等传统石油基材料为主。化学回收是废塑料资源化的一种重要手段,传统催化剂的改良、新型催化剂的开发以及反应装置的优化将是该领域未来的研究重点。     

果蔬气调包装计算机辅助设计方法研究

目的为提高果蔬气调包装的设计效率,对果蔬气调包装CAD方法进行研究。方法在建立果蔬气调包装数学模型、果蔬产品呼吸速度及塑料薄膜透气性数据库的基础上,利用Matlab GUI开发果蔬气调包装CAD系统,并进行实例研究。结果系统界面清晰,操作简便。可根据产品的理想气调环境参数,选择合适的薄膜材料,计算有利于气体交换的塑料薄膜面积或厚度。果蔬产品呼吸速度数据库包含17种果蔬呼吸速度模型,塑料薄膜透气性能数据库包含21种塑料薄膜材料的透气性数据。结论该系统可快速进行常见果蔬产品的气调包装设计。     

跨境再生HDPE生产塑料罐包装的碳足迹评价研究

目的 探索塑料包装的碳足迹评价技术,建立健全该行业碳足迹改进的技术方法.方法 运用生命周期评价法,对塑料罐包装的碳足迹建模、数据采集和计算结果进行分析,并讨论关联因素的影响;基于碳足迹评价结果,提出评价对象生命周期碳足迹的改进方案.结果 研究发现系统边界内单件20 L塑料罐包装的碳足迹为2.48 kg-CO2-eq;再生料改性、吹塑成型的碳足迹贡献度达17.5％,75.8％;新料使用的单项碳足迹达1.02 kg-CO2-eq,再生料质量分数增加5％,碳足迹下降了7.67％;单位容积碳足迹随着包装容积增大而减小.结论 由于原生资源消耗量的减少,再生塑料资源的利用,可以明显改善包装生产的物料和电力碳足迹;同配比下大体积规格的包装设计对于提高单件包装的利用效率起到积极作用;跨境再生料的使用、合理包装设计、绿色电力应用等均是改善塑料罐包装碳足迹的有效方案.     

Transport Coefficients of Eucalyptol through Various Polymeric Films

This study presents the determination of the transport properties of eucalyptol, which is a key aroma compound in fresh tropical herbs through different polymeric packaging materials. Packaging films used in this study were polyethylene, polypropylene, Nylon, polyethylene terephthalate and polylactide (PLA1 and PLA2). Test films were immersed in the 1000 ppm of aroma compound and stored in amber vials. The concentrations of aroma compounds extracted from films were determined using gas chromatography. Diffusion, solubility, permeability and partition coefficients were calculated from sorption kinetics. Results show that the diffusion and solubility coefficients of eucalyptol were lowest in PLA1 and highest in polyethylene. Solubility coefficients were associated with partition coefficients as well as solubility parameters and contact angle values. Primary factor determining solubility was affinity between the aroma compounds and the polymeric films. Transport coefficients of eucalyptol in the vapor phase followed the same trends as in the liquid phase with about 3‐fold greater. Understanding interaction phenomenon between the key aroma compound and major packaging films may contribute to improvements in film selection and the design of food packaging applications. Finding from this research contributes toward future development of the high‐aroma barrier materials. Copyright © 2011 John Wiley & Sons, Ltd.     

Prediction of plastic film thickness based on gas permeability and validation with ‘Kyoho’ table grapes for optimal modified atmosphere packaging

Modified atmosphere packaging (MAP) storage has become a useful technique for extending the shelf life of fruit and vegetables. However, the success of MAP depends on many factors, including types of fresh products, storage conditions, and the characteristics of the packaging films. To achieve the optimal gas composition in the package headspace and improve the postharvest quality of fresh produce, the packaging film with appropriate barrier properties needs to be selected. This study aimed to predict the film thickness by applying produce respiration rate and package film permeability data measured in given product weight and storage conditions. An available film (eg, 25‐μm‐thick low‐density polyethylene) was used to pack fresh produce, and the respiration rate of fresh produce and in‐package O₂ and CO₂ concentrations at steady state were measured. Permeability of the film was calculated based on mass balance, and the thickness of the film could be predicted if the recommended target O₂ and CO₂ concentration was obtained from the literature. To validate the predicted thickness value, an experiment was conducted by packaging fresh table grapes in bags of the predicted thickness. The effect of packaging with different film thicknesses on the quality of the fruit was determined. The results showed good agreement between the predicted and the experimental in‐bag O₂ and CO₂ concentrations, and the MAP with predicted thickness (90 μm) film was more effective in maintaining postharvest quality of grapes during low‐temperature storage than the thinner films (30 and 60 μm) and the control.     

碳钢用新型气相防锈包装膜的制备与性能研究

目的 以正癸酸（CA）为缓蚀剂制备一种新型气相防锈包装膜,以期拓展中长链脂肪酸类缓蚀剂在防锈包装中的应用。方法 利用挤出吹塑法制备了含不同质量分数（0、0.5%、1.0%、2.0%）CA的低密度聚乙烯（LDPE）基气相防锈包装膜,试验测定分析CA添加量对包装膜光学、力学、阻隔、缓蚀等性能的影响。结果 CA的添加可改善LDPE包装膜的韧性,其质量分数为0.5%、1.0%、2.0%时,可使包装膜的水蒸气阻隔性能分别提高3.7%、17.9%、14.8%;CA质量分数为1.0%和2.0%的包装膜可使低碳钢在交变湿热环境下保持9周期无锈蚀,满足国标对气相防锈包装膜的相关性能要求。结论 添加CA的气相防锈包装膜可有效延缓碳钢腐蚀,为该类新型气相防锈包装膜研制提供技术支撑。     

双向拉伸多层共挤复合薄膜的生产制备和进展

高性能薄壁化和多层复合是当前塑料包装薄膜的发展趋势。双向拉伸多层共挤复合薄膜不仅可以满足包装行业对薄膜多功能性的要求,还具有"减薄"功能,可大幅度减少同类塑料薄膜的用量,降低生产成本。文中分别介绍拉伸取向和多层共挤关键技术、商业化薄膜生产设备和几种主要的薄膜产品,如双向拉伸聚丙烯(BOPP)薄膜、双向拉伸聚酯(BOPET)薄膜、双向拉伸聚酰胺(BOPA)薄膜、双向拉伸聚乳酸(BOPLA)薄膜和双向拉伸聚乙烯(BOPE)薄膜,着重讨论了BOPE薄膜研究现状及未来展望。     

Effect of Polyethylene Packaging Modified with Silver Particles on the Microbial,Sensory and Appearance of Dried Barberry

Low‐density polyethylene (LDPE) packages containing submicrometre‐sized silver particles (Ag‐LDPE) were produced by extrusion method and used as packaging material for barberry packaging. The effects of Ag‐LDPE packages on the microbial factors, apparent color and sensory factors of dried barberry were investigated in comparison with the pure polystyrene packages. Ag‐LDPE packages showed antimicrobial effects on barberry compared with pure polystyrene packages. In comparison with pure polystyrene packages, Ag‐LDPE film with 2 weight percent (wt%) of silver particles revealed antimicrobial activity against mold and total bacteria count of approximately 2.3 and 2.84 log₁₀ reductions in colony‐forming units, respectively. Ag‐LDPE packages in concentration of more than 1 wt% of silver particles preserved the appearance quality of the barberry better than pure polystyrene packages. The barberries packaged in Ag‐LDPE film with 1 wt% of silver particles retained their red color and brightness for approximately 2 to 3 weeks more than barberries packaged in pure polystyrene films. Ag‐LDPE packages assisted in the improvement of aroma, taste and total acceptance of barberry in comparison with pure polystyrene packages except in the low concentration of silver particles of approximately 0.02 wt%. The taste, aroma, appearance and also total acceptance of barberries packaged in Ag‐LDPE film with 1 wt% silver particles were preserved for approximately 2 to 3, 1 to 4, 2 to 5 and 2 to 4 weeks, respectively, more than barberries packaged in pure polystyrene films. Copyright © 2012 John Wiley & Sons, Ltd.     

The effect of high‐pressure food processing on the sorption behaviour of selected packaging materials

The sorption behaviour and flavour‐scalping potential of selected packaging films in contact with food simulant liquids (FSLs) (ethanol and acetic acid solutions) were evaluated after high‐pressure processing (HPP). The films used were monolayer polypropylene (PP), a multilayer (polyethylene/nylon/ethylene vinyl alcohol/polyethylene: PE/nylon/EVOH/PE), film and a metallized (polyethylene terephthalate/ethylene–vinyl acetate/linear low‐density polyethylene: metallized PET/EVA/LLDPE) material. D‐limonene was used as the sorbate and was added to each of the FSLs. After HPP treatment at 800 MPa, 10 min, 60°C, the amount of D‐limonene sorbed by the packaging materials and the amount remaining in the FSL was measured. Untreated controls (1 atm, 60°C and 40°C) were also prepared. Extraction of the D‐limonene from the films was performed using a purge/trap method. D‐limonene was quantified in both the films and the FSL, using gas chromatography (GC). The results showed that D‐limonene concentration, in both the films and the food simulants, was not significantly affected by HPP, except for the metallized PET/EVA/LLDPE. Significant differences in D‐limonene sorption were found in comparison with the control pouches. The results also showed that changes in temperature significantly affected the sorption behaviour of all films. Copyright © 2004 John Wiley & Sons, Ltd.     

薄膜包装对娃娃菜采后贮藏品质的影响

目的探究适用于娃娃菜采后贮藏保鲜的包装材料。方法采用4种不同厚度的聚乙烯薄膜(10,20,30,40μm)包装娃娃菜,以市场销售的原包装薄膜为对照,测定在常温(23±2)℃下贮藏28 d的品质变化,之后以筛选出的薄膜材料为研究对象,进一步分析其对娃娃菜采后贮藏品质的影响。结果与其他薄膜包装相比,厚度为30μm的聚乙烯薄膜包装材料对娃娃菜的保鲜效果最好,其可溶性糖、蛋白含量分别为13.49 mg/g,3.79 mg/g,MDA的质量摩尔浓度为1.51μmol/g。与对照组相比,厚度为30μm的薄膜包装能够有效抑制娃娃菜表面菌落总数的生长,延迟腐烂现象的发生,维持其组织较高的抗坏血酸、总酚、可溶性糖、总硫苷和萝卜硫素含量。主成分法综合评价的结果也显示,厚度为30μm的薄膜包装对减缓娃娃菜品质劣变的效果更理想。结论厚度为30μm的聚乙烯薄膜包装能更好地维持采后娃娃菜的贮藏品质,适宜用作采后娃娃菜的包装贮运材料。     

Development of an Active Thermoplastic Film with Oxygen Scavengers Made of Activated Carbon and Sodium Erythorbate

An active thermoplastic film made of low‐density polyethylene (LDPE) filled with oxygen scavengers made of powdered activated carbon (PAC) impregnated with sodium erythorbate (SE) was developed for packaging applications. Initial tests indicated that the impregnation of PAC with SE enhanced the heat resistance of SE, thereby allowing processing at temperatures typical of LDPE manufacturing. Subsequently, LDPE films with PAC/SE particles were manufactured in coupons that represented a typical juice package, and experiments indicated that these films absorbed 3.57 mg of oxygen in 11 days. This amount corresponded to 80% the concentration of oxygen in the headspace of the package. Furthermore, findings indicated that active particles alone have 10 times higher oxygen absorption capacity than the active LDPE film. Finally, the physical properties of the film were characterized by microscopy where oxygen scavengers showed a good dispersion within the matrix. However, 20 wt.% of these active particles decreased tensile strength of the film by 53%. Copyright © 2014 John Wiley & Sons, Ltd.     

循环包装箱全生命周期碳足迹计算方法研究

目的 针对目前循环箱碳足迹的计算缺乏统一标准且相关研究较少，使循环箱的环保价值存疑的问题，本文对循环包装箱的碳足迹进行研究，旨在建立一种适用于循环包装的基于生命周期评价(LCA)方法的碳排放计算模型。方法 基于全生命周期评价方法，参考国内A循环包装企业B2B应用场景，采用eFootprint软件及数据库量化分析。由于聚丙烯材料具有可循环利用的特点，在快递循环包装中广泛应用，本文以聚丙烯材料的循环箱为例进行碳足迹的研究。以1 m²的循环快递包装箱为功能单位，采用“从摇篮到坟墓”的方法对其生产、运营、回收等过程的物耗、能耗及环境排放进行环境影响量化比较。结果 研究评价分析了各个单元过程中对全球变暖潜值这一环境指标的贡献值。结果显示，循环包装箱碳排放贡献主要来源于4个方面:循环使用过程运输排放，约占总排放的57.95%;其次为原材料聚丙烯，约占总排放的24.25%;电力排放包括生产、清洗2个阶段的电力，占总排放的11.71%;报废后垃圾焚烧处理过程排放，占总排放的5.33%。使用近50次的二氧化碳当量为9.854 1 kg/m²。结论 循环包装单次使用排放低于相同面积单位5层瓦楞纸箱的碳排放，说明在理想条件下循环包装具有较高的环保价值。     

Comparison of Various Packaging Films for Mango Export

This study compared the effects of the use of various types of packaging films in maintaining quality, preserving bioactive compounds and extending shelf life of the ‘Nam Dok Mai’ mango. The principal techniques for maintaining the quality of mangoes are based on modified atmosphere packaging using highly gas‐permeable films and an ethylene‐removing mechanism. The films studied were non‐perforated highly gas‐permeable film, non‐perforated ethylene‐absorbing highly gas‐permeable film (HNPE), micro‐perforated highly gas‐permeable films (HMP) and common non‐perforated polyethylene film (LNP). These films were compared with non‐packaging treatment, which served as a control (C). Gas composition (O₂, CO₂ and C₂H₄) in the package headspace was monitored during storage at 12°C. The quality of mangoes were assessed by weight loss, colour (L* a* b*), texture, total soluble solids, titratable acidity, total phenolics, total flavonoids, ethanol concentration and sensory quality. Equilibrium‐modified atmospheres of 5 kPaO₂ + 5 kPaCO₂ and 4 kPaO₂ + 5 kPaCO₂ were achieved in the non‐perforated highly gas‐permeable film and HNPE packs, respectively. Carbon dioxide accumulation was observed in the HMP and LNP packs where CO₂ reached 17 and 10 kPa, respectively, after storage for 10 days. The shelf life of mangoes was extended to 40 days with HNPE, 35 days with HNP, and 30 days with HMP, as compared with 20 days with control and 5 days with LNP. HNPE, the film incorporated with fine particles of mordenite framework inverted‐type zeolite with ethylene‐absorbing ability, could further extend the shelf life of mangoes in addition to modified atmosphere packaging alone. Copyright © 2011 John Wiley & Sons, Ltd.