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Packaging Applications (packaging + application)
Selected AbstractsPoly(lactic acid) properties as a consequence of poly(butylene adipate- co -terephthalate) blending and acetyl tributyl citrate plasticizationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2008Maria-Beatrice Coltelli Abstract This study was aimed at the modulation of poly(lactic acid) (PLA) properties by the addition of both a low-molecular-weight plasticizer, acetyl tributyl citrate (ATBC), and a biodegradable aliphatic,aromatic copolyester, poly(butylene adipate- co -terephthalate) (PBAT). PLA/PBAT, PLA/ATBC, and PLA/PBAT/ATBC mixtures with 10,35 wt % ATBC and/or PBAT were prepared in a discontinuous laboratory mixer, compression-molded, and characterized by thermal, morphological, and mechanical tests to evaluate the effect of the concentration of either the plasticizer or copolyester on the final material flexibility. Materials with modulable properties, Young's modulus in the range 100,3000 MPa and elongation at break in the range 10,300%, were obtained. Moreover, thermal analysis showed a preferential solubilization of ATBC in the PBAT phase. Gas permeability tests were also performed to assess possible use in food packaging applications. The results are discussed with particular emphasis toward the effects of plasticization on physical blending in the determination of the phase morphology and final properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Oxygen Barrier Properties of Whey Protein Isolate Coatings on Polypropylene FilmsJOURNAL OF FOOD SCIENCE, Issue 1 2003S.-I. Hong ABSTRACT Oxygen permeation characteristics of whey protein isolate (WPI) coatings on polypropylene (PP) films were investigated to examine the feasibility of WPI coating as a novel biopolymer oxygen barrier for food packaging applications. Heat-denatured aqueous solutions of WPI with several plasticizers including glycerol, sorbitol, sucrose, propylene glycol, and polyethylene glycol were applied on the surfaces of PP films previously treated with corona discharge. Among plasticizers used, sucrose conferred the best oxygen barrier property to the WPI-coated films. Oxygen permeability (OP) of the resulting WPI-coated films increased significantly with temperature, showing very good agreement with the Arrhenius model. OP of the coated films also increased exponentially with relative humidity. [source] Modeling the dynamics of reactive foaming and film thinning in polyurethane foamsAICHE JOURNAL, Issue 2 2010G. Harikrishnan Abstract Flexible polyurethane foams are widely used in cushioning and packaging applications. A model for the dynamics of formation of polyurethane foams is presented, which includes thinning of foam lamellae. Experimental measurements for water blown flexible foam formulations at different water concentrations are presented to validate the model. Adiabatic temperature rise measurements during foaming are used to obtain the kinetic parameters of the reactions of isocyanate with polyol and water. The variation of foam density during foaming is studied by weight loss and video shooting methods and both are compared to estimate the amount of blowing gas lost during foaming. The average thickness of the foam lamellae of the solid foam is obtained by SEM measurements. The predictions of the model show good agreement with the experimental measurements of temperature and density with time and the final lamellar thickness. The results are important for understanding the cell opening process. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] Improvement of ,-tocopherols long-term efficiency by modeling its heterogeneous natural environment in polyethyleneJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 5 2006Clara Strandberg Abstract The natural antioxidant vitamin E (,-tocopherol) is of interest to use in packaging applications to decrease the amount of toxic products migrating into food and drugs. We have earlier shown that the long-term efficiency of ,-tocopherol in polyethylene (PE) films is poor. ,-Tocopherol is located in the lipid phase of the cell in vivo and it has been revealed that it is more efficient in a polar substrate. PE is more hydrophobic and homogenous than the heterogeneous and hydrophilic lipid phase. Three different additive systems were investigated to model ,-tocopherols heterogeneous natural environment in PE. Two of these had carboxylic acid groups, EAA and polyTRIM/PAA core-shell particles (Core), and the third, oat starch, had no carboxylic acid groups. The materials were thermally aged and characterized by chemiluminescence (CL), FTIR, chromatography, and thermal analysis. The EAA system as well as the Core system improved the antioxidant properties of ,-tocopherol in PE, and the Core system had the best performance. We know that starch has stabilizing properties in PE, but it had no effect on the efficiency of ,-tocopherol. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1660,1666, 2006 [source] How about alternatives to phthalate plasticizers?JOURNAL OF VINYL & ADDITIVE TECHNOLOGY, Issue 4 2003Leonard G. Krauskopf Phthalate plasticizers have historically served as the preferred plasticizers to impart flexibility to PVC and several other polar polymers. They provide a desirable balance of cost and performance properties. Their acceptable and safe use is unmatched in medical appliances, food processing, and packaging applications, as well as in many other end uses. Potential alternatives do not have the historical record of acceptable performance found with phthalate plasticizers. Nevertheless, the "Precautionary Principle" has caused certain segments of society to clamor for alternates to phthalate plasticizers. This paper reviews known "non-phthalate" plasticizers and provides comparisons to the traditional "General Purpose" (GP) phthalate plasticizers; "General Purpose" plasticizers are those that impart optimum overall performance properties in PVC at lowest cost. [source] Characterization for water vapour barrier and heat sealability properties of heat-treated paperboard/polylactide structurePACKAGING TECHNOLOGY AND SCIENCE, Issue 8 2009Kimmo Lahtinen Abstract The moisture barrier and heat sealability properties of polylactide (PLA) extrusion-coated paperboard were investigated. The first part of the study focused on the influences of coating weight and surroundings temperature and relative humidity on the water vapour transmission rate (WVTR) of the structure. The outcome arising from this part was a simple and practical equation that allows calculating the WVTR as a function of PLA coating weight under specific thermo-hygrometric conditions. The second part of the study investigated the effect of heat treatments between 100 and 150°C on the WVTR and heat sealability of a 20,g/m2 PLA-coated paperboard. According to the results, the lowest WVTR values achieved were about 2.5 times lower than the WVTR of the untreated structure. Presumably, the PLA coating experienced two types of reordering mechanisms: crystalline growth and packing of the amorphous structure. The greatest barrier improvement was achieved when both of these mechanisms were accumulated effectively. This was observed from the samples after a 40,min treatment at 130°C. Ultimately, the crystalline growth was experienced by PLA at 100,130°C temperatures. The packing of the amorphous section, which was also accumulated at higher temperatures, was suggested to be the decisive factor influencing WVTR. According to the heat sealing results, the heat treatments causing crystalline growth resulted in considerably increased sealing temperatures and reduced applicability of the material in high-speed packaging applications. The treatments at 140,150°C caused only a slight increase in the sealing temperature and maintained the sealing performance of PLA. Copyright © 2009 John Wiley & Sons, Ltd. [source] Polariscopic imaging and vibrational characterization of hybrid films for packagingPACKAGING TECHNOLOGY AND SCIENCE, Issue 6 2008Iari-Gabriel Marino Abstract Polymeric films (low-density polyethylene and oriented polypropylene) for packaging applications coated with organic,inorganic nanocomposite hybrids have been prepared by sol-gel process. Tetraethoxysilane and two different organic phases, polyvinyl alcohol and a diblock copolymer polyethylene-polyethylene glycol were used as precursors. Information about the hydrolysis and polycondensation degrees was obtained by investigating the vibrational features of the coatings by means of attenuated total reflectance-Fourier transform infrared and Raman spectroscopies. Through a new polariscopic imaging technique, the bi-dimensional maps of the optical anisotropy of the samples, both as-prepared and under mechanical strain, were obtained. The maps showed inhomogeneous retardation and nearly flat azimuth distributions. The anisotropy properties of the samples depended mainly on the substrates and were not influenced by the coatings, while the optical transmission was slightly better for the tetraethoxysilane-polyvinyl alcohol sample. Copyright © 2008 John Wiley & Sons, Ltd. [source] A simple model for the interaction between water vapour and oxygen transmission in multilayer barrier materials intended for food packaging applicationsPACKAGING TECHNOLOGY AND SCIENCE, Issue 4 2008Marianne Jakobsen Abstract The low oxygen permeability of the ethylene-vinyl alcohol copolymer, EVOH, is outstanding, but is also known to be very sensitive to moisture uptake and cannot be used as a monolayer packaging material. In this paper, theory is presented in order to calculate the average water activity of the EVOH layer at steady state and the corresponding oxygen barrier for different multilayer structures using various polymer types and layer thicknesses. Multilayer materials can be designed for different food packaging applications and storage conditions, in order to keep the relative humidity of the barrier below recommended 75%, by varying the thickness of the outside versus the inside protective layers and/or varying the water vapour transmission rate of the outside versus the inside layer. The conclusion reached is that to retain the optimal barrier properties and thereby the optimal protection of the food, asymmetric multilayer structures are necessary. Copyright ©2007 John Wiley & Sons, Ltd. [source] Comparison of the degradability of poly(lactide) packages in composting and ambient exposure conditionsPACKAGING TECHNOLOGY AND SCIENCE, Issue 1 2007Gaurav Kale Abstract The adoption of biodegradable polymeric materials is increasing in food and consumer goods packaging applications, due to concerns about the disposal of petroleum-based polymers and the increasing cost of petroleum-based polymer resins. Currently, poly(lactide) (PLA) polymers are the biggest commercially available bio-based polymeric packaging materials. As the main motivation for adopting biopolymers is environmental, there is a need to address the degradability and environmental performance of biodegradable packages. The aim of this study was to investigate and compare the degradation of two commercially available biodegradable packages made of PLA under real compost conditions and under ambient exposure, using visual inspection, gel permeation chromatography, differential scanning calorimetry and thermal gravimetric analysis. A novel technique to study and track the degradability of these packages under real compost conditions was used. Both packages were subjected to composting and ambient exposure conditions for 30 days, and the degradation of the physical properties was measured at 1, 2, 4, 6, 9, 15 and 30 days. PLA bottles made of 96% l -lactide exhibited lower degradation than PLA delicatessen (,deli') containers made of 94% l -lactide, mainly due to their highly ordered structure and, therefore, their higher crystallinity. The degradation rate changed as the initial crystallinity and the l -lactide content of the packages varied. Temperature, relative humidity and pH of the compost pile played an important role in the rate of degradation of the packages. First-order degradation kinetics and linear degradation trends were observed for both packages subjected to composting conditions. Copyright © 2006 John Wiley & Sons, Ltd. [source] Influence of co-monomer structure on properties of co-polyamide packaging filmsPACKAGING TECHNOLOGY AND SCIENCE, Issue 1 2002P. Scarfato Abstract In this work a series of co-polyamides were prepared by random polymerization of ,-caprolactam in presence of four different co-monomers at a percentage of 5% w/w, with the aim of verifying their suitability as film-forming materials. The effects of structural changes induced in the ,-caprolactam homopolymer by co-monomers were evaluated in both molten and solid states. Rheological tests in shear and elongational flow were performed to evaluate the processability of co-polyamides. Cast films were obtained and their thermal, mechanical and transport properties were evaluated to establish the performances of the co-polyamides in view of packaging applications. The results indicate that co-polyamide films having a partially aromatic structure display the best mechanical performances and show a significant improvement in barrier properties to gases compared to the homopolymer. Copyright © 2002 John Wiley & Sons, Ltd. [source] | |||||||||||||