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Aluminum Foil (aluminum + foil)
Selected AbstractsComparison of flat film to total package water vapour transmission rates for several commercial food wrapsPACKAGING TECHNOLOGY AND SCIENCE, Issue 1 2002Matthew D. Steven Abstract The barrier properties of a package are the sum of material and seal permeations. Although addressed for hermetically sealed and modified atmosphere packages, little consideration of total package permeation has been given to commercial food wraps. Standard protocols were used to compare the water vapour transmission rates (WVTRs) of materials and packages for seven commercial food wraps: aluminum foil; poly(vinylidene chloride) (PVdC) film; three poly(ethylene) (PE) films; an adhesive-modified PE film; and plasticized poly(vinyl chloride) (PVC) film. Water ingress for a complete package was compared to calculated material permeation based on film WVTRs. Film-to-glass adhesion strength was also measured. Model systems (desiccant) were compared to foods at ambient and refrigeration temperatures. Aluminum foil had the lowest material WVTR (0.10 g/h/m2), closely followed by PVdC (0.13 g/h/m2). These WVTRs were approximately five-fold lower than the PEs (,0.65 g/h/m2), which were nearly 10-fold lower than PVC (4.9 g/h/m2). The adhesive-modified PE film had the lowest difference between material and package transmission rates (0.7 E-03 g/h), approximately half that of the PVdC film (1.1 E-03 g/h), which was significantly lower than the remaining films (2.3 E-03 ,3.9 E-03 g/h). The adhesive PE film had the strongest film,glass adhesion. Ambient food product test results were similar to model system (desiccant) results, but refrigerated trials showed significantly different relative package transmission rates. This was attributed to the reduced adhesion of most wraps at refrigeration temperatures. Copyright © 2002 John Wiley & Sons, Ltd. [source] Scanning electron microscopic observation of oil/wax/water/surfactant systemINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 2 2005K. Ikuta We observed the internal structure of an oil/wax/water/surfactant system using a scanning electron microscope to investigate the relationship between its hardness and state of wax crystal. The molten wax (hydrogenated jojoba oil, ceresin, polyethylene wax, carnauba wax, or microcrystalline wax) was cast in a home-made spiral mold of aluminum foil for preparing the test specimen for SEM observation. In hydrogenated jojoba oil a fine frame-like crystal structure, the so-called ,card-house structure,' was observed but not in other waxes. The mixture of hydrogenated jojoba oil and water showed a few small droplets deposited on the roundish wax frame-like structure. On the other hand, waxes other than hydrogenated jojoba oil did not change their internal structure when they were mixed with water. This result suggested that hydrogenated jojoba oil showed uniquely high affinity for water. In the system of oil, water, surfactant, and various kinds of waxes, their crystal structure, hardness, and the shape of dispersed water particles were remarkably changed with the combination of waxes. In the system with ceresin and carnauba wax, the hardness measured by a card-tension meter was high, and the internal crystal structure was fine and amorphous. The water particle in the ceresin and carnauba wax system had a smaller diameter than that in the system containing hydrogenated jojoba oil. The system containing hydrogenated jojoba oil showed a card house-like wax crystal structure without high hardness. It was considered that the wax crystal structure played an important role in providing hardness and in contributing to the water distribution in the oil/wax/water/surfactant system. [source] Structural characterization and dynamic water adsorption of electrospun polyamide6/montmorillonite nanofibersJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2008Qi Li Abstract A facile compounding process, which combined nanocomposite process with electrospinning for preparing novel polyamide6/organic modified montmorillonite (PA6/O-MMT) composite nanofibers, is reported. In this compounding process, the O-MMT slurry was blended into the formic acid solution of PA6 at moderate temperatures, where the nanosized O-MMT particles were first dispersed in N,N -dimethyl formamide solvent homogeneously via ultrasonic mixing. Subsequently the solution via electrospinning formed nanofibers, which were collected onto aluminum foil. The O-MMT platelets were detected to be exfoliated at nanosize level and dispersed homogeneously along the axis of the nanofibers using an electron transmission microscope. Scanning electron microscope and atomic force microscope were used to analysis the size and surface morphology of polyamide6/O-MMT composite nanofibers. The addition of O-MMT reduced the surface tension and viscosity of the solution, leading to the decrease in the diameter of nanofiber and the formation of rough and ridge-shape trails on the nanofiber surface. The behavior of the dynamic water adsorption of composite nanofibers was also investigated and discussed in this article. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Photografting of unable-to-be-irradiated surfaces.JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007Abstract In this article, a batch liquid-phase process was reported, by which the photo-initiated grafting polymerization could be carried out on the dark surfaces that were not directly irradiated by UV light. In the reaction system, an aluminum foil was placed horizontally to reflect UV light back and form a dark area underneath where the grafting polymerization took place. The occurrence of the polymerization was demonstrated by gravitational analyses and XPS spectra. The factors affecting the grafting reaction have been studied and the results showed that increasing irradiation time, reaction temperature, and benzophenone concentration and decreasing distance (D) between the light area and the place where grafting reaction took place were beneficial to the grafting reaction. The highest grafting density was obtained at a acrylic acid concentration of 15 vol %. Moreover, some further investigations were also made. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 118,124, 2007 [source] Pyrolysis of tetra pack in municipal solid wasteJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 8 2001Chao-Hsiung Wu Abstract The pyrolysis of tetra pack in nitrogen was investigated with a thermogravimetric analysis (TGA) reaction system. The pyrolysis kinetics experiments for the tetra pack and its main components (kraft paper and low-density poly(ethene) (LDPE)) were carried out at heating rates (,) of 5.2, 12.8, 21.8,K,min,1. The results indicated that the one-reaction model and two-reaction model could be used to describe the pyrolysis of LDPE and kraft paper respectively. The total reaction rate of tetra pack can be expressed by the summation of the individual class of LDPE and kraft paper by multiplying the weighting factors. The pyrolysis products experiments were carried out at a constant heating rate of 5.2,K,min,1. The gaseous products were collected at room temperature (298,K) and analyzed by gas chromatography (GC). The residues were collected at some significant pyrolysis reaction temperatures and analyzed by an elemental analyzer (EA) and X-ray powdered diffraction (XRPD). The accumulated masses and the instantaneous concentrations of gaseous products were obtained under the experimental conditions. The major gaseous products included non-hydrocarbons (CO2, CO, and H2O) and hydrocarbons (C1,5). In the XRPD analysis, the results indicated that pure aluminum foil could be obtained from the final residues. The proposed model may be supported by the pyrolysis mechanisms with product distribution. © 2001 Society of Chemical Industry [source] Controlling Light Oxidation Flavor in Milk by Blocking Riboflavin Excitation Wavelengths by InterferenceJOURNAL OF FOOD SCIENCE, Issue 9 2009J.B. Webster ABSTRACT:, Milk packaged in glass bottles overwrapped with iridescent films (treatments blocked either a single visible riboflavin [Rb] excitation wavelength or all visible Rb excitation wavelengths; all treatments blocked UV Rb excitation wavelengths) was exposed to fluorescent lighting at 4 °C for up to 21 d and evaluated for light-oxidized flavor. Controls consisted of bottles with no overwrap (light-exposed treatment; represents the light barrier properties of the glass packaging) and bottles overwrapped with aluminum foil (light-protected treatment). A balanced incomplete block multi-sample difference test, using a ranking system and a trained panel, was used for evaluation of light oxidation flavor intensity. Volatiles were evaluated by gas chromatography and Rb degradation was evaluated by fluorescence spectroscopy. Packaging overwraps limited production of light oxidation flavor over time but not to the same degree as the complete light block. Blocking all visible and UV Rb excitation wavelengths reduced light oxidation flavor better than blocking only a single visible excitation wavelength plus all UV excitation wavelengths. Rb degraded over time in all treatments except the light-protected control treatment and only minor differences in the amount of degradation among treatments was observed. Hexanal production was significantly higher in the light-exposed control treatment compared to the light-protected control treatment from day 7; it was only sporadically significantly higher in the 570 nm and 400 nm block treatments. Pentanal, heptanal, and an unidentified volatile compound also increased in concentration over time, but there were no significant differences in concentration among the packaging overwrap treatments for these compounds. [source] Production and Shelf Stability of Multiple-Fortified Quick-Cooking Rice As a Complementary FoodJOURNAL OF FOOD SCIENCE, Issue 7 2008S. Porasuphatana ABSTRACT:, Rice-based complementary foods normally contain inadequate amounts of several micronutrients, such as iron, calcium, and zinc. This study aimed at improving the quality of commercially produced rice-based complementary foods. The analysis centered on identifying a rice-based complementary food that is safe, stable, sensory acceptable, and economical in terms of fortificants (iron, calcium, zinc, thiamine, folate) and effectively packaged for industrial production and distribution. Product colors were mostly in green-yellow tone and slightly changed to more yellow during storage. Sensory acceptability was affected by changes in odor and rancidity but not in color. Rancidity scores were low in aluminum foil laminated plastic bags (ALU). Lipid oxidation significantly increased during storage, but at a slower rate when sodium citrate and ALU were used. Color differences of raw products were detected but not in the cooked ones. Mineral and vitamin losses during processing were 2% to 11% and 20% to 30%, respectively, but no losses were found during storage. FeSO4+ NaFeEDTA added with sodium citrate resulted in the most acceptable product for all packagings. The multiple-fortified quick-cooking rice (MFQCR) developed from this study could be a potentially useful tool for combating micronutrient deficiencies among infants and young children in the countries where rice is the staple food. [source] The Application of Ultraviolet Irradiation to Exogenous Sources of DNA in Plasticware and Water for the Amplification of Low Copy Number DNAJOURNAL OF FORENSIC SCIENCES, Issue 4 2006Jeannie Tamariz B.S. ABSTRACT: Using high sensitivity forensic STR polymerase chain reaction (PCR) typing procedures, we have found low concentrations of DNA contamination in plasticware and water assumed to be sterile, which is not detected by standard DNA procedures. One technique commonly used to eliminate the presence of DNA is ultraviolet (UV) irradiation; we optimized such a protocol used in the treatment of water, tubes, plates, and tips for low copy number DNA (LCN) amplification. UV light from a Stratalinker® 2400 was administered to 0.2, 1.5 mL tubes, and PCR plates contaminated with up to 500 pg of DNA. They were subsequently quantified with an ALU-based real-time PCR method using the Rotorgene 3000. Overall, there was a decrease in concentration of DNA recovered as the duration of treatment increased. Nonetheless, following 45 min of irradiating a PCR plate with 500 pg of DNA, nearly 6 pg were still detected. However, when the plate was raised within an inch of the UV source, less than 0.2 pg of DNA was detected. Additionally, lining the area around the samples with aluminum foil further reduced the amount of time necessary for irradiation, as only 30 min eliminated the presence DNA in the raised PCR plate. Similar experiments were conducted using tubes filled with a solution of DNA and water in equivalent concentrations for 50, 15, and 1.5 mL tubes with comparative results. It is plausible that the aluminum foil increased the amount of reflection in the area thereby enhancing penetration of UV rays through the walls of the plasticware. This protocol was tested for the possibility of inhibitors produced from irradiation of plastic tubes. As our protocols require less irradiation time than previous studies, PCR sensitivity was not affected. Moreover, the lifespan of the UV lamps was extended. Our findings demonstrate that this method is useful as an additional precautionary measure to prevent amplification of extraneous DNA from plasticware and water without compromising the sensitivity of LCN DNA amplifications. [source] Slow programmable and ultra-rapid freezing of human embryosJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 4 2008Teraporn Vutyavanich Abstract Aim:, To compare the outcomes of slow freezing with ultra-rapid freezing (URF) of cleavage-stage human embryos on aluminum foil. Methods:, Two-cell mouse embryos were used to test our method of ultra-rapid freezing. The embryos were randomly allocated to a non-frozen control (208 embryos), and slow (204 embryos) or ultra-rapid freezing groups (204 embryos). Immediate survival rate, further cleavage and blastocyst formation were compared. After validating our ultra-rapid freezing method on mouse embryos, we applied a similar ultra-rapid freezing protocol to human embryos. Consecutive human frozen/thawed embryo transfer (FET) cycles from October 1998 to June 2005 were reviewed. The survival rate, further cleavage rate and the pregnancy outcomes were compared between the URF and slow programmable freezing. Results:, Mouse embryos in the URF group survived the freezing/thawing process better than those in the slow freezing group (93.1% vs 82.8%, P = 0.001). Blastocyst and hatching blastocyst formation of the surviving embryos were comparable in the URF and slow freezing group (59% vs 58.6%, P = 0.944 and 32.6% vs 42%, P = 0.066, respectively). There were 146 human FET cycles in the URF group and 28 cycles in the slow freezing group. The immediate survival of embryos was higher in the URF group than in the slow freezing group (87.9% and 64.3%, P < 0.001). There was no significant difference in the mean number of embryos per transfer (3.7 ± 1.3 and 3.3 ± 1.2, P = 0.178), clinical pregnancy rate per transfer (28.5% and 21.4%, P = 0.444) and implantation rate per embryo (10.98% and 10.9%, P = 0.974) in the URF or slow freezing groups. Conclusion:, Our in-house URF method gave comparable results to slow programmable freezing. Although the risk of potential contamination is a major drawback of the present ultra-rapid freezing technique, future refinement will minimize or entirely eliminate this concern. [source] Comparison of flat film to total package water vapour transmission rates for several commercial food wrapsPACKAGING TECHNOLOGY AND SCIENCE, Issue 1 2002Matthew D. Steven Abstract The barrier properties of a package are the sum of material and seal permeations. Although addressed for hermetically sealed and modified atmosphere packages, little consideration of total package permeation has been given to commercial food wraps. Standard protocols were used to compare the water vapour transmission rates (WVTRs) of materials and packages for seven commercial food wraps: aluminum foil; poly(vinylidene chloride) (PVdC) film; three poly(ethylene) (PE) films; an adhesive-modified PE film; and plasticized poly(vinyl chloride) (PVC) film. Water ingress for a complete package was compared to calculated material permeation based on film WVTRs. Film-to-glass adhesion strength was also measured. Model systems (desiccant) were compared to foods at ambient and refrigeration temperatures. Aluminum foil had the lowest material WVTR (0.10 g/h/m2), closely followed by PVdC (0.13 g/h/m2). These WVTRs were approximately five-fold lower than the PEs (,0.65 g/h/m2), which were nearly 10-fold lower than PVC (4.9 g/h/m2). The adhesive-modified PE film had the lowest difference between material and package transmission rates (0.7 E-03 g/h), approximately half that of the PVdC film (1.1 E-03 g/h), which was significantly lower than the remaining films (2.3 E-03 ,3.9 E-03 g/h). The adhesive PE film had the strongest film,glass adhesion. Ambient food product test results were similar to model system (desiccant) results, but refrigerated trials showed significantly different relative package transmission rates. This was attributed to the reduced adhesion of most wraps at refrigeration temperatures. Copyright © 2002 John Wiley & Sons, Ltd. [source] Preparation and Electrical Properties of an Anodized Al2O3,BaTiO3 Composite FilmJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2008Xianfeng Du A highly stable, water-based barium titanate BaTiO3, BT, sol was synthesized using a sol,gel route through a chelate lactate technique. Dried BT precursor powders were measured by thermal gravimetry,differential thermal analysis and X-ray diffraction. It was found that BT powders first converted into barium carbonate BaCO3, Ti complex, and intermediate phase Ba2Ti2O5CO3, and then transformed into perovskite phase BaTiO3. The crystallization temperature was about 550°C. The low-voltage etched aluminum foils were covered with BT sol by dip coating, and then annealed at 600°C for 30 min in air. After that, the samples were anodized in a 15 wt% aqueous solution of ammonium adipate. The voltage,time variations during anodizing were monitored, and the electrical properties of the anodic oxide film were examined. It was shown that the specific capacitance, the product of specific capacitance and withstanding voltage, and leakage current of samples with a BT coating were about 48.93%, 38.50%, and 167% larger than that without a BT coating, respectively. [source] Dust from comet Wild 2: Interpreting particle size, shape, structure, and composition from impact features on the Stardust aluminum foilsMETEORITICS & PLANETARY SCIENCE, Issue 1-2 2008A. T. Kearsley By comparison to laboratory shots of known particle dimensions and density, using the same velocity and incidence geometry as the Stardust Wild 2 encounter, we can derive size and mass of the cometary dust grains. Using scanning electron microscopy (SEM) of foil samples (both flown on the mission and impacted in the laboratory) we have recognized a range of impact feature shapes from which we interpret particle density and internal structure. We have documented composition of crater residues, including stoichiometric material in 3 of 7 larger craters, by energy dispersive X-ray microanalysis. Wild 2 dust grains include coarse (>10 ,m) mafic silicate grains, some dominated by a single mineral species of density around 3,4 g cm,3 (such as olivine). Other grains were porous, low-density aggregates from a few nanometers to 100 ,m, with an overall density that may be lower than 1 g cm,3, containing mixtures of silicates and sulfides and possibly both alkali-rich and mafic glass. The mineral assemblage is very similar to the most common species reported from aerogel tracks. In one large aggregate crater, the combined diverse residue composition is similar to CI chondrites. The foils are a unique collecting substrate, revealing that the most abundant Wild 2 dust grains were of sub-micrometer size and of complex internal structure. Impact residues in Stardust foil craters will be a valuable resource for future analyses of cometary dust. [source] Laboratory simulation of impacts on aluminum foils of the Stardust spacecraft: Calibration of dust particle size from comet Wild-2METEORITICS & PLANETARY SCIENCE, Issue 2 2006A. T. Kearsley The ability of soft aluminum alloy to record hypervelocity impacts as bowl-shaped craters offers an opportunistic substrate for recognition of impacts by particles of a potentially wide size range. In contrast to impact surveys conducted on samples from low Earth orbit, the simple encounter geometry for Stardust and Wild-2, with a known and constant spacecraft-particle relative velocity and effective surface-perpendicular impact trajectories, permits closely comparable simulation in laboratory experiments. For a detailed calibration program, we have selected a suite of spherical glass projectiles of uniform density and hardness characteristics, with well-documented particle size range from 10 ,m to nearly 100 ,m. Light gas gun buckshot firings of these particles at approximately 6 km s,1 onto samples of the same foil as employed on Stardust have yielded large numbers of craters. Scanning electron microscopy of both projectiles and impact features has allowed construction of a calibration plot, showing a linear relationship between impacting particle size and impact crater diameter. The close match between our experimental conditions and the Stardust mission encounter parameters should provide another opportunity to measure particle size distributions and fluxes close to the nucleus of Wild-2, independent of the active impact detector instruments aboard the Stardust spacecraft. [source] | ||||||||||||||||