By: Debomitra Dey
In prehistoric times there was no need to package food, as it was consumed immediately and prepared locally. With the advent of civilization it became a necessity to preserve food for longer durations and serving individuals inhabiting in the civilization hence, man thought of preserving food in animal skins, bark of trees, leaves, wood and bamboo. And with the need for sustainable packaging, transportation and protection of food and advancement in technology the dependence on glass, metal (tin, copper), ceramics, plastics increased. In the current times we observe the function of packaging was initially protection, containment has now served to be the “silent salesman” of the product, as the package communicates with the consumers, as the consumer tends to recognize the product by the means of labelling and branding, the package advertises itself and makes it appealing to the buyer. As the consumer base is increasing with the rise in global population the need to conserve our resources is necessary to serve the globe, the increasing use of plastic packages leads to increased levels of pollution. Hence, measures should be taken to administer the pollution levels by use of alternate renewable sources for packaging.
The application and reliance on plastic in packaging is ubiquitous and used on a large scale in industries like food and beverage industry, healthcare, pharmaceuticals, cosmetics, consumer based products. The first manmade plastic was introduced to the world by Alexander Parkes in London in the year 1862, and since then due to the burgeoning technological innovations and inventions there was no looking back; we have witnessed a myriad of plastic materials like cellophane, polyethylene (high density and low density), polyvinyl chloride (PVC), polypropylene, polyvinyl alcohol (PVA), cling films and other bio-based polymers like poly-lactic acid (PLA). Plastics are preferred material for packaging due to their low cost for manufacture, high performance and endurance; hence make them suitable for transportation for long distances.
The conventionally used plastics are non-degradable, and that has caused half of the issues and challenges faced on a global scale due to liberal usage of plastics by industries for consumer products. Plastics are derived from non-renewable resources, the materials employed for preparation of plastic include petroleum, crude oil, coal, cellulose, and natural gas. Synthetic plastics mimic the role of natural materials, and carbon is the backbone of most of the plastics. The plastic packaging material can be designed by changing the chemical configuration of the carbon atoms in the matrix, which can be exploited by the manufacturer to fabricate plastic based upon the application for example, for packaging of milk HDPE (high density polyethylene) is employed, meat is packaged in LDPE (low density polyethylene), coffee, powdered milk is packaged in LPDE, PET (polyethylene terephthalate) films or laminated pouches.
Since the antediluvian paper has been used by man to preserve food and it is made from intertwined network of fibres of cellulose and as we are aware the source of cellulose is from plants, this attributes to the biodegradable nature of paper. Paper is light weight, low cost, easily available, and it acts as an opus for the manufacturers to communicate with the consumers. The practice of using paper on a commercial scale started around the 20th century. Paper possesses low mechanical strength, and lacks grease resistance hence, when paper is impregnated with materials like waxes, resins, lacquers, plastics and lamination of aluminium it improves the endurance, flexibility, seal-ability, and printability. Furthermore it is used over wide temperature ranges from high temperatures of boiling water and heating by conventional radiation and microwave to frozen foods. Paper and paperboard is used for packaging of products such as dry foods – cereals, bread, bakery products, chocolates and confectionaries, tea and coffee, frozen foods, chilled foods and ice cream. Likewise it is also used for distribution of products in corrugated boxes. Paper board is thicker than paper and made up of multiple layers, they are employed for making cartons, boxes and trays, usually used as tertiary or quaternary packaging. Laminated paper has enhanced barrier properties, sealable properties due to impregnation of aluminium or plastic like PP.
Impact of Packages on the Environment
In current times, the need for bio-compostable packaging is rising with the growing levels of global warming. Many researchers and scientists have formulated the necessity of biodegradable polymers like cellulose, chitosan, starch, and pectin, and also wastes produced from corn industry, sugarcane industry provide raw material for biodegradable polymers; these materials alone cannot offer the mechanical strength to the package, hence blending with non-degradable plastics makes these materials green and environment friendly and increases the sustainability of the materials. We need to curb the usage of fossil fuels like petroleum hence strictly following the regulations and reducing the carbon footprint. In the consequent paragraphs the implication and methods to develop sustainability of plastics and paper packaging are discussed.
It is difficult to recycle plastics and it takes almost 50 years for degradation of plastic packages; they contribute to approximately 15 percent of discarded waste on Earth. Plastic remains are found in urban areas and water bodies. As they are not disposed properly by the consumer, this in turn affects the animals (sea and land dwellers) and humans and augments the pollution in the environment. To combat such issues government and other regulatory bodies are promoting plastic recycling and sustainability of plastic packages. Scientists have discussed the concept of Life Cycle Assessment (LCA) to measure the green characteristics of a product or system to access the environmental impacts and resources utilization, and it is regulated by ISO 14040. The amount of energy consumed, and the hazardous materials emitted by the product like CO2 emission, ozone depletion during its life cycle is quantified by LCA. This in turn enables scientists and researchers to design a sustainable package with the aim to preserve the food, and reduce the amount of energy invested to manufacture the packaging material, and would reduce load the environment.
Correspondingly, plastic waste management systems are employed by recycling of plastic; it can be either achieved by reusing or energy recovery/composting. Some countries employ the method of returning PET, PP bottles after use this concept reduces the accumulation of plastic in the environment. It is estimated that precisely 40 percent of total plastics is used in the area of packaging and out of this 5-7 percent consists of household wastes by weight in United Kingdom. The recovery of plastics in domestic markets can be tedious, as plastics need to segregated, usually HDPE and PET are recycled around 50,000 tonnes of PE films are used for making film for trash collection.
As discussed above, paper and paper board are biodegradable, have low environmental impact as the main component is wood (cellulose) that is naturally sustainable. Hence, it is implied for production of paper and paper board packages it is of utmost importance to follow sustainable forest management. This can be achieved by replenishment of trees, and promoting biodiversity, conservation of water and maintenance of green pastures. It is estimated that about 10 percent of wood harvested is utilized by the paper and paperboard industry, and hence the land allocated for forestry and volume of trees grown are increasing.
Paper and paperboard can be recycled as fibre and is employed to make new paper packages this is the main advantage of employing paper packages. In China paper consumption is rising and the demand is fulfilled by recovered fibre. The process of recovery can be seen in Figure.
All in all paper and board is biodegradable and renewable (sustainable) products and do not affect the environment during the manufacturing process and use. The only need is to maintain the forest lands for abundance of wood, and protecting the biodiversity within the forests and paper product packages can be reused which increases its sustainability in the market.
To increase the sustainability of both plastic and paper packages, the LCA should be thoroughly studied and new packages should be designed by keeping in the mind the impact it would have on the environment. Plastic packages can be replaced by biodegradable polymers or the synthetic polymers can be blended with biodegradable polymers like starch, cellulose, chitosan which would in turn increase the tensile strength of the package, provide better barrier properties, increased shelf life and biodegradability. In 2013 about 65 percent of market was dominated by biodegradable packaging, this shows the trend of increase in the market for bio compostable packages. Now when considering the case of paper, paper itself is biodegradable thus the need for rise in paper production would demand to conserve the natural resources and proper recycling management of paper products.
1. Vignali G., Enviornmetal Footprints of Packaging, Springer Science+ Business Media Singapore 2016, pp: 1-22.
2. Marsh K, Bugusu B., Journal of Food Science 2007, vol 72 pp: R39- R55.