فصلنامه علوم و فنون بسته بندی
پیاپی 19 (پاییز 1393)

Nowadays, packaging is known as a science in developed countries, and their products are presented, with the best packaging methods, to the global markets. Among various types of products, handcrafts which are representatives of national identities and cultures, have a specific place. Since packaging is the first step of interaction between the product and the customer, suitable design, colors, compatibility of the packaging with the product and etc. are considered as influential elements to improve product's quality. The present paper is trying to identify packaging techniques and methods for teaching them. The data was gathered through field and library research and the methodology is analytic-descriptive.

Nowadays the application of paper in packaging is more than plastic materials, due to its properties such as lightness and biodegradability. Paper has weak barrier properties such as permeability to water vapor, gases and oil. Use of synthetic polymers such as polyethylene, latex and polyvinyl alcohol for improvement of barrier properties of the paper packaging leads to environmental problems. To eliminate these problems, films and coatings based on polysaccharides, proteins, and lipids or a mixture of them have entered to packaging industry. One of the proteins which is abundant and cheap in Iran and recently efforts have been made to find new applications for it is whey protein. Current study has investigated the effects of coating weight on the strength (tear and burst), barrier (air, oil and water permeability) and physical properties (coating weight) of whey protein coated light paper. In this study, two speeds of 30 and 50 mm/s were used for paper coating and the influence of the two different coating weight on paper’s properties was evaluated. Results show that the strength and barrier properties of coated papers were improved by increasing the coating speed due to decrease in coating weight. Furthermore, the application of whey protein concentrate- sucrose is suitable for coating the papers used for packing oily foods such as pizza and confectioneries.

Increasing in production and consumption of plastics and petroleum composites in human's daily life, leads to accumulation of large amounts of non-biodegradable plastic wastes and it has caused many environmental problems. Evaluations show that each year large amounts of plastics are produced in the world and much plastic trash discarded into the marine environment and it accumulates. Since biopolymers obtained from renewable resources and therefore, they are biodegradable, application of them compared to petroleum based polymers have lower negative environmental impacts. The use of biodegradable polymers must be confirmed from two points of view; First, the environmental perspective; this means that the material must degrade rapidly in the environment and second, from the industrial view point, i.e. the material characteristics in industry such as durability and efficiency are expected. Low cost, renewability, availability and good thermal stability are the main advantages of biodegradable polymers. In this study, some of the most important cellulose derivatives that are commonly used in the production of biodegradable films for food packagings have been investigated.

Continuous improvement in performance is essential for the success of the paperboard industry. Strength improvement has always been an important consideration for papermakers. Strength increasers are critical components for manufacturing of paperboard. These materials provide not only the required strength quality to paper products but also can improve the machine productivity and process efficiency. A variety of strength improver chemicals are available in the market, including natural polymers (starch, CMC) and synthetic resins (PAM, PAE). Choosing a strength aid depends on a number of factors, including their effectiveness (or impact on a specific quality parameters), the cost, the effect on machine runnability and productivity, convenience of use, product availability and shelf life. In this paper, the use of high levels of anionic starch which is then fixed using a combination of PAC/poly DADMAC and also other additives to improve resistance of paper and paperboard was studied.

This paper reviews the possible effects determined on polymeric food packaging films by the simultaneous application of pressure (P) and temperature (T) in high pressure pasteurization and sterilization treatments of packaged foodstuffs. Both theoretical modeling and experimental issues are discussed. In fact reversible and irreversible effects that could occur in single film as well as in multilayer film structures have been reviewed and correlated to the variation of structure a land morphological properties of the polymeric materials, under P/T conditions relevant for the specific application. The structural changes of the amorphous and crystalline domains of polymer films could possibly occur in response to pressure and/or temperature conditions, which, in turn, result in detectable effects on properties of packaging materials. Particular attention has been devoted to addressing issues like irreversible alter-action off functional (i.e., barrier to gases and water vapor, scalping and migration phenomena) and mechanic alprop-erties of the packaging materials in a relationship with a modification of degree of crystalline, aging of the amorphous phase, elimination of multilayer films, rubbery to glassy state transition promoted by pressure and plasticization induced by absorption of low molecular weight compounds. Industrial relevance: High pressure processing (HPP) is steadily gaining's food presser vat ion method that preserves natural sensory and nutritional attributes of food with a minimal quality loss. In fact, packaged foods processed by using this technique maintain most of their original texture and nutritional qualities, additionally exhibiting an extended shelf-life. Industrially, the selection of the proper polymeric materials as well as the packaging structure become extremely important when both high pressure and high temperature are employed for high pressure sterilization processes. In this context, an important issue that is relevant for industrial applications is to predict the possible effects of treat-mends on the structure and morphology of the materials which, in turn, can determine relevant effects on mechanical, functional (i.e., gas and vapor barrier properties) and aesthetic (e.g., see-through clarity) properties. In fact, modification of the crystalline level, density change of amorphous regions and possible hydrolysis phenomena could hamper the use of the packaging material for the HPP applications. Moreover, multilayer flexible films can, in some cases, display delimitation phenomena leading to unacceptable midi fictions of the aspect as well as of the integrity of the packaging structure.

In this study, the effect of gelatin-chitosan edible coating on the quality of chicken breast during 9 days of refrigerated storage (4 was investigated. Three concentrations of gelatin (3, 6 and 8% W/V) and two concentrations of chitosan (1 and 2% W/V) were used to prepare the coating materials. Samples was divided in 7 group, no coating (control), gelatin 3% and chitosan 1% (sample 2), gelatin 6% and chitosan 1% (sample 3), gelatin 8% and chitosan 1% (sample 4), gelatin 3% and chitosan 2% (sample 5), gelatin 6% and chitosan 2% (sample 6), gelatin 8% and chitosan 2% (sample 7). The samples were analyzed for microbiological (total microbial count), volatile nitrogen bases and peroxide value during a 9 days with 3 days interval. These parameters was significantly high in the control samples. Microbial growth, volatile nitrogenous bases and peroxide in samples with a higher percentage of chitosan and gelatin was slower. The amount of volatile nitrogen bases was high in control samples because this samples have high total microbial count. Significant difference between gelatin 3% with gelatin 6 and 8% was observed. So it can be said, that the coating maintain quality of the samples during the whole preservative period.

By developing technology, "the environmental contaminants" is counted as an inevitable subject. The most important result of controlling and removing the industrial pollutants is stepping towards sustainable development. Printing and packaging industries are problematic due to the presence of polymers, adhesives, alcohols, ink and detergents. These materials can make the wide range of industrial pollutions. Actions such as application of recyclable metalized paper, condensing liquid wastes, using open-stay ink and etc. have been taken to reduce industrial pollutants. This research discussed different ways to reduce and control printing and packaging contaminants.