17.5% of both rigid and film plastic is recycled on average in Brazil, or around 200,000 tonnes per year. There are no separate figures for plastic film. On average, the material accounts for 29% of total plastic separated by cities with curbside collection programs. The recycling rate for plastics in Europe has in recent years stabilized at 22%, with some countries having legislation that is complex and costly for the local population, contrary to Brazil where recycling is carried out in a spontaneous manner.

Plastic film is normally used for supermarket bags, garbage bags, milk packaging, agricultural crop covering, and protective wrapping for food in the refrigerator or microwave. The material constitutes 42.5% of plastic packaging in general in the United States.

In the US, 51% of packages and bags used to wrap and bag products are composed of plastic. Around 44% is paper and 4% is aluminum foil.

Low-density polyethylene resin (LDPE) and that of polypropylene (PP) are the most used in Brazil, each accounting for 23% of the polymers consumed in the Brazilian market for plastics. Annual production of plastics in Brazil in 2001 was 3.7 million tonnes and 3.9 million tonnes in 2002.

The material accounts for between 5% and 10% of the weight of garbage, depending on the region.

The Englishman Alexander Parkes produced the first plastic in 1862. Plastic quickly became one of the greatest phenomena of the industrial age, providing more durability and lightness. However, as most of it was not biodegradable, it also became the target of criticism regarding its disposal in landfills, which have grown in tandem with the explosion in population.

Plastic recycling began with the plastics industry itself, to make up for losses in production. As the material began to be recuperated in greater quantities and separated from refuse, a new market appeared, absorbing modern technology and allowing the production of articles with an ever-growing percentage of recycled plastic.

Variety of Plastic Resins

Around 80% of plastic film bags and packaging are made of polyethylene and 20% of polypropylene, polyvinyl chloride (PVC) – used in food packaging – and other resins. Some films mix two or more polymers, which can cause problems in recycling, such as cracks and loss of mechanical resistance.

Some resins are difficult to identify with the naked eye. Most methods used in the selection of plastics for recycling are based on observing the material when burnt – the color of the flame or the smoke and the smell. To facilitate identification, the plastics manufacturing sector have adopted the use of standardized symbols.

Variety of Colors

Half of the plastic film available on the market is pigmented, while the other half is white. As it contains dyes, the plastic should be separated by color, or at least those with print should be isolated from the print-free, to obtain greater selling value.

Strict Specifications of the Material

Contaminants include food, fats, paper, labels, staples and dirt in general, reducing its resale price. This frequently occurs with plastic mixed in with garbage, where there has been no separated collection. It must undergo various cleaning processes before being sent for recycling.

Reduction at source

Lighter than other materials, plastic film has contributed to reducing generation of garbage. Without plastic, solid urban waste would weigh four times as much and take up twice as much space, according to German research institute GFV (Gesellschaft für Virologie).

Composting

Plastic film cannot be composted.

Incineration

Plastic is highly combustible, with a calorific value of 18,700 BTUs per kilo, in the case of polyethylene. Urban waste taken as a whole has combustible power of 4,500 BTUs per kilo. Energy recycling is not practiced in Brazil.

Landfill

Plastic film is difficult to biodegrade. Its substitution for plastics that are either biodegradable or photo-degradable (decomposing when exposed to light) is now being studied. Even so, its decomposition is slow in sanitary landfills.

After separation from refuse, plastic film is baled for recycling. At the recycling plant, the material is put through a sort of giant cake mixer that heats the plastic with the friction of its rotor blades, transforming it into a kind of flour. A little water is then added to cause a sudden cooling that causes agglutination: the molecules of the polymers contract, increasing the plastic’s density, and turning it into grains.

It then weighs enough and is sufficiently dense to pass down the funnel of the structure, the machine that melts the material and turns it into spaghetti-like strips. In the final stage, the strips undergo a cooling bath and are then shredded into pellets, which are bagged and sold to the manufacturers of plastic ware.