Conventional Plastic packaging is harmful for the environment as it is non-biodegradable. Plastics take hundreds of years to dis-integrate naturally. Until that time it just goes into landfills as piles and piles of non biodegradable waste. The plastic sheets/bags/films that get trapped in the soil and prevent water or air to permeate, hence making the soil infertile. In order to dispose the plastic waste, sometimes it is burnt, which pollutes the environment and also releases harmful greenhouse gases and their accumulation in the atmosphere. Therefore, it is very important to either replace conventional plastics with biodegradable packaging materials or recycle plastics so as to minimize their environmental impact.
There are four possible green approaches:
Recycling Conventional Plastics
Compared with other materials, such as glass and metal, plastic polymers require greater processing in order to recycle them. Due to the high molecular weight of their large polymer chains, plastics are difficult to mix. A macro molecule interacts with its environment along its entire length, so total energy required to mix it effectively is large. Heating alone cannot dissolve such a large polymer chain, so plastics must often be of nearly identical composition to mix efficiently. When different types of plastics are melted together, they tend to phase-separate, like oil and water, and set in these layers. The phase boundaries cause structural weakness in the resulting material, meaning that polymer blends are useful in only limited applications.
Another barrier to recycling is the widespread use of dyes, fillers, and other additives in plastics. The polymer is generally too viscous to economically remove fillers, and would be damaged by many of the processes that could cheaply remove the added dyes. Additives are less widely used in beverage containers and plastic bags, allowing them to be recycled more often.
Biodegradation or metabolization of conventional plastics.
Conventional Plastics can be completely metabolized into carbon dioxide and water by certain bacteria under proper conditions. Although the presence of such bacteria having the ability of decomposing conventional plastics is known for sometime now, in practical working, it is quite difficult to achieve effective metabolization as it is difficult to separate organic materials such as paper, liquids, food items from the underlying polymer layer without expensive cleaning and sanitizing procedures.
Bio Polymers are carbon neutral and are renewable, because they are made from plant materials which can be grown indefinitely. These plant materials come from agricultural non food crops. Therefore, the use of biopolymers would create a sustainable industry. In contrast, polymers which are derived from petrochemicals will eventually deplete. In addition, biopolymers have the potential to cut carbon emissions and reduce CO2 quantities in the atmosphere: this is because the CO2 released when they degrade can be reabsorbed by crops grown to replace them: this makes them close to carbon neutral. Biopolymers are biodegradable, and some are also compostable. Some biopolymers are biodegradable: they are broken down into CO2 and water by microorganisms. Some of these biodegradable biopolymers are compostable: they can be put into an industrial composting process and will break down by 90% within six months. Example : Polyglyconic acid made out of sugar beet, Polylactic acid made out of starch (e.g. corn starch).
Regenerated Cellulose/ Paper
Paper/ regenerated cellulose packaging is the sustainable option in more ways than one. Paper / regenerated cellulose packages help curbing climate change. They are produced from renewable resources. Packaging solutions can be so designed which combine Paper / regenerated cellulose packaging with materials that place minimum load on the environment ie paper laminated with aluminum foil and coated with wax. Material consumption can be minimized both by efficient packaging design as well as by use of recycled materials and therefore limit waste generation without compromising on the product’ strength properties. Products can even be made of completely biodegradable materials, which can be composted. Use of paper/regenerated cellulose can help customers make a difference – saving trees, reducing landfill space, waste water, greenhouse gases, and minimizing energy.
Paper can be coated with bio-degradable materials such as wax to improve moisture/gas barrier properties of paper. Wax paper decomposes to water plus energy and carbon dioxide at the same rate as leaves in a forest. Some of the other advantages of paper based packaging are : Positive environmental perception in the public eye – Not only environmentally sensitive members of the public recognise the advantages of the paper-based packaging. Due to its natural "make and feel", paper based packaging is correctly perceived as the most environmental friendly packaging for consumers worldwide. Environmental benefits – Neither primers nor anti-static lacquers are needed to print paper. Natural solution – In nature leaves and plants use wax as a protective coating. In this sense waxed coated paper is a copy of nature. Recyclability of paper – Next to glass, paper has the highest recycling rate of all packaging materials. Recycled paper is used in many applications such as corrugated board and graphical papers. Paper waste can be reconstituted into firelogs, building and construction composites such as furniture and door filling. Where recycling systems are not in place, incineration with energy recovery is a further option. Printable with water-based inks – Paper has the advantage of being perfectly printable with water-based inks.
Other examples of Regenerated Cellulose/ Paper based packaging: Cellophane, Aluminium Foil+Paper laminate.