PET Bottle

From CopperWiki

Jump to: navigation, search

Polyethylene Terephthalate, or PET, is one of the many classifications of plastic. Produced by the chemical industry, it is a thermoplastic polymer resin that belongs to the polyester family. One of the most important raw materials used in man-made fibres, such as rayon, nylon and polyester, PET bottle grade is mainly used for bottling carbonated soft drinks and mineral water, as also by the food packaging industry.


[edit] Characteristics of PET Bottles

  • Gas barrier: Helps isolate CO2 and O2 gasses, thus enabling long-term storage.
  • Lightweight: A PET bottle weighs only 1/15-1/20 of a similar-sized glass bottle.
  • Superior moulding: The moulding capabilities of PET bottles are far superior to that of aluminium cans, glass or paper.
  • Positive external appearance: Since PET Bottles are transparent, the content of the bottle can be viewed, thereby increasing their demand.
  • Unbreakable: In addition to being transparent, they are also unbreakable, making it safe for the user and cost effective for the manufacturers of the conent being stored in these bottles.

While around 60 per cent to 70 per cent of the world’s PET production is attributable to the production of synthetic fibres, the remaining is used up by the bottle-producing industry. This sector is set to grow as bottled water is the fastest growing beverage industry in the world.

[edit] Production of PET Bottles

The production of PET bottle grade is achieved by the process of solid-state polymerization (SSP) of PET melt, which increases the thickness of the polymer by vacuum treatment. The process does not involve any other raw material.

Though the largely-held belief is that ingredients used in the production of PET aren’t harmful, recent research and tests conducted by Professor William Shotyk, director of the Institute of Environmental Geochemistry at Heidelberg University in Germany, has indicated that plastic containers commonly used for bottling water leak ‘antimony’ (a chemical used in the making of PET bottles) into the water. Antimony has been deemed a potentially deadly toxin. The research concluded that the level of poison is directly proportionate to the amount of time that water is stored in a PET bottle—the longer you store water, the larger the amount of poison. Small doses of antimony can make you ill and depressed. Larger quantities can cause violent vomiting and even death. The research has been published in the Journal of Environmental Monitoring, published by the Royal Society of Chemistry. Contamination of Canadian and European bottled waters with antimony from PET containers.

However, while this research has been certified, it is held that further research needs to be done in order to ascertain the effects of antimony and at what level it becomes dangerous to humans. For instance, Elizabeth Griswold, director of the Canadian Bottled Water Association, disagrees with the findings, and believes that “the levels do not pose a risk to humans, they are simply trace elements”.

[edit] Reuse of Plastic Water Bottles

According to scientists in the US, reused bottles are a breeding ground for bacteria. Most plastic bottles—such as those used for carbonated soft drinks—bought at the store are usually meant to be disposed off after having the soft drink. So, if you are planning on reusing those same bottles to store water, washing them out with soap and water is not an effective solution. The advisable thing to do is to avoid leaving half-drunk bottles for long periods and disposing off the bottle instead of using it to store water in the refrigerator, as such bottles are fertile ground for further breeding of bacteria.

Also, it is important to know the recycling code for every plastic container that we buy. This equips us with the knowledge of what can be recycled, reused and disposed. It is imperative that we know the kind of plastic used for different products. The recycling code is given as a numerical coding at the bottom of each container.

There are seven different types of plastic resins that are commonly used and they are listed as below:

Recycling Code Type of Plastic Uses
1 Polyethylene Terephthalate (PET) Soda and water containers, various waterproof packaging and tennis balls
2 High-density Polyethylene (PE) Milk, detergent and oil bottles, toys and plastic bags
3 Vinyl/Polyvinyl Chloride (PVC) Food wrap and vegetable oil bottles
4 Low-density polyethylene Plastic bags, shrink-wrap and garment bags
5 Polypropylene Refrigerated containers, most bottle tops, some carpets, food wraps and chairs (back/seats)
6 Polystyrene Throw-away utensils, meat and protective packing
7 Others Layered or mixed plastic

While most plastic containers bear the chasing arrows icon with a number in the middle, signifying their being recyclable, it is only the ‘1’s and ‘2’s that can be recycled. There is no market for bottles numbered ‘3’ through ‘7’. In fact, most of us do not know that a ‘3’ in the recycle symbol indicates that the plastic is made of PVC, which cannot be recycled due to the many different toxic additives that have been used to soften or stabilise PVC. Therefore, though PVC comprises only a small fraction of the container market, it is highly contaminative. For example, it is believed that just one PVC bottle can contaminate a recycling load of 100,000 PET bottles.

[edit] Recycling Manual

Please remember the following practices when putting out your PET and plastic bottles for collection.

  • Remove the label
  • Remove the cap
  • Rinse the bottle
  • Empty the bottle of water

This prevents extraneous material from hindering the recycling process.

[edit] Did you Know?

  • The PET bottle was patented by Nathaniel Wyeth in 1973.
  • The first PET bottle was recycled in 1977.
  • In 1960, a one-gallon plastic milk container weighed 120 grams. Today, it weighs just 65 grams.
  • 10% of the average grocery bill pays for packaging(mostly paper and plastics).
  • Recycling a ton of PET containers can save 7.4 cubic yards of landfill space.
  • Every year, Americans make enough plastic film to shrink-wrap the state of Texas.
  • Recycled PET can be used to make many new products, such as carpet, fabric for

T-shirts, shoes, sweaters and coats, luggage, fiberfill for sleeping bags and even toys!

  • In Sweden the recycling rate of PET bottles in 2004 was 80 percent compared to the U.S which was 15 percent.
  • According to the Container Recycling Institute, U.S plastic recycling rates have been in decline for the past 10 years
  • The plastic waste in the US is increasingly being shipped to places like China, which now boasts the world's biggest plastic recycling plant in Beijing). And according to, only 1 percent to 3 percent of plastic bags ever get recycled.
  • No one really knows how long it takes to break down, because plastic simply hasn't been around long enough. Such is the uncertainty that environmentalists estimate that it could be anywhere from 500 to 1,000 years.

[edit] References

  • The poison lurking in your plastic water bottle
  • Contamination of Canadian and European bottled waters with antimony from PET containers

[edit] See Also