Papers by Keyword: Packaging Film

Abstract: In this work, water vapor permeability of linear low density polyethylene (LLDPE)/ethylene vinyl acetate copolymer (EVA) film is improved by incorporation of zeolite A as filler (0-25%wt) for prolonging shelf-life of fresh produces. All films were characterized by SEM, DSC, tensile testing, contact angle measurement and tested for water vapor permeability (WVP). The shelf-life of Bird’s eye chili in the film samples was also tested at 10°C for 21 days. It was found that zeolite A particles were virtually dispersed in EVA phase. Accordingly, crystallinity and tensile properties of LLDPE/EVA/Zeolite A films is independent to zeolite loading. Despite, when zeolite loading was increased, the dispersion became low. The film’s wetting behavior was enhanced by increasing zeolite content in the LLDPE/EVA/Zeolite A films. The observed increase in the film’s polarity significantly enhances the WVP. Therefore, less water condensed can be found inside the package made with LL80E20Ze25 film, as compared to LLDPE or LLDPE/EVA film. The LL80E20Ze25 also possesses comparable tensile properties to the commercial LLDPE film and hence can used as packaging for extending the shelf-life of fresh produces.

Abstract: The quality of kiwifruit with three different packaging films were studied on the storage days. These kiwifruits were stored at 0±0.5°Cfor 120 days. Results showed that the kiwifruits with PVC films can keep a relative good quality during the storage life.

Abstract: SiO₂/PET composite packaging film was prepared by depositing SiO₂ on PET film substrates through magnetron sputtering technology. The state of SiO₂ particles and its dispersion properties in PET substrates were characterized by scanning electron microscope (SEM) and bonding strength tester. The effects of the sputtering process parameters and intermediate layer on the bonding strength of the coating-substrate system were investigated. Results show that the bonding strength of coating-substrate system firstly increases and then decreases with the increase of sputtering process parameters. It is up to a maximum at the argon flow of 10 mL/min, radio-frequency power of 250 W and sputtering time of 70 min; and it is 0.14 MPa, 0.22 MPa and 0.19 MPa, respectively. The bonding strength of coating-substrate system increases with the increasing background pressure. Meanwhile, we find that the bonding strength of coating-substrate system is improved by depositing A1₂O₃ intermediate layer between SiO₂ film and PET substrates.

Abstract: In order to reveal the effect of packaging films on quality of fresh cut broccoli, three different properties of films were selected as materials. The effect of packaging films on headspace gas composition in the bag, respiratory rate and sensory quality of fresh cut broccolis were studied. The results showed that the samples in PE2 exhibited the best quality. The samples in PE1 had less quality than PE2. Although broccolis in PE3 had the lower O₂ concentration and highest CO₂ concentration, which retarded a great extent of respiration rate than others, but this condition induced anaerobe respiration, and then leading to the worst sensory quality.

Abstract: Gas permselective packaging film is an emerging material which enables it with gas selective permeation functions so as to keep the preservation atmosphere of inner packages and thus extends the shelf-life of fresh fruits. In this work, Hexamethyldisilazane and Hexamethyldisiloxane were applied as the precursors to comparatively investigate the behavior on the preparation of gas permselectivy film, respectively. Also, Different reaction parameters such as plasma input power, deposition time and monomer proportions were investigated respectively. The film properties were analyzed by Water Contact Anglemeter, Surface Profiler thickness test, Fourier Transform Infrared Spectroscopy (FTIR), water vapor transmission rate test (WVTR) and oxygen transmission rate test (OTR). The results showed that HMDS is better than HMDSO to be the precursor for the formation of gas permselectivity films.The film formed from the monomer of HMDS changed the gas permeability of the film reversely which is more suitable for the preparation of such materials.

Abstract: This paper is concerned with the preparation of cellulose packaging films with high oxygen permeability. The films were prepared from cotton pulp and wood pulp by the cast-wiped method using N-methymorpholine-N-oxide (NMMO) as a solvent. The effects of processing parameters on the structure and performance of cellulose films were also studied. The results show that for optimum processing of the films cotton pulp was the preferred raw material, the optimum pulp concentration in the casting solution was 5%, and the optimum temperature for the coagulation bath was 40°C. Using the above process conditions resulted in packaging films with high oxygen permeability making them suitable for use in packaging fruits and vegetables.

Abstract: Cellulose-based composites packaging films containing various amounts of modified nano-SiO₂ were prepared by utilizing hardwood pulps as natural cellulose resource through NMMO-technology to improve the mechanical properties, permeability for oxygen and water vapor etc. The tensile strength, elongation at break, thermal stability and permeability of the cellulose composites films as a function of the content of modified nano-SiO₂ were studied. The investigation suggested that the capabilities of composites films with 2 wt.% modified nano-SiO₂ added were improved largely, compared to pure cellulose films, when the diameter of particles is 30nm. The tensile strength was increased from 8.95 to 17.37 MPa and the elongation at break of the cellulose composites films was improved from 41.11% to 58.34%. The composites films with rational mechanical properties have adjustable oxygen permeability (7.90×10^-15-72.18×10^-15 cm³·cm/cm²·s·Pa) and water vapor permeability (7.12×10^-13-5.32×10^-13g·cm/cm²·s·Pa). And thermal stability of the composites films was advanced through adding modified nano-SiO₂.

Abstract: The cellulose packaging film was prepared by natural broad-leaved pulp and LiCl/DMAc through adjusting coagulation bath conditions. In this study, the effects of its concentration and temperature on the physical structures, permeability for oxygen and water vapor of the films were measured. Based on the SEM observation, the cross section becomes dense when the concentration of LiCl/DMAc in the coagulation is bellow 15% and temperature is 20 °C, however, the opposite tendency with increasing of the LiCl/DMAc and temperature in the coagulation. The mathematical model about the coagulation bath concentration and temperature with oxygen permeation flux (OPF) and water vapor permeability (WVP) coefficient of cellulose films was also set up.

Abstract: The aim of the present work was to investigate the moisture sensitivity of soy protein isolate (SPI) films blending with poly (vinyl alcohol) (PVA) plasticized by glycerol. Water vapor permeability (WVP) was measured based on the contents of PVA and glycerol in films. WVP values of various SPI/PVA films with/without glycerol were in the range of 8.25 and 10.9 g mm/m2 h kPa. The results showed that WVP values decreased with the increasing content of PVA. Moreover, XRD tests confirmed that the glycerol would insert into the macromolecular blending structure and destroy the crystalline of blends, and the crosslinkage between glycerol molecules and SPI reduced the interstitial spaces in protein matrix, thus allowing for decreasing diffusion rate of water molecules through the films.