|is a desired secondary resource. PET, the abbreviation for Polyethylen-terephthalat, is fully recycable and may be used for manufacturing new products in many industrial areas such as packaging for detergents, cosmetics, high-quality carpets, foils, car spare parts, pillow fillings for allergic persons and fabrics. Its versatility in the many industries therefore makes it unreplacable.|
|The Recycling Process|
Collection -- Where It All Starts
With an abundance of bottles, recycler capacity, and potential end uses, the key to successful recycling of PET plastics lies with consumers throughout the world. Only they can properly identify post-consumer containers and initiate the collection process.
PET containers are identified by a resin identification code imprinted on the side or bottom of the container. PET bottles in the United States, which are usually clear or transparent green, carry the resin identification code " 1 " and the symbol "PETE." They may also be recognised by the dot, or circular gate, centrally located on the bottom.
More than 7,000 communities in the United States have curbside collection programs that provide the consumer with bins for the collection and separation of recyclable glass, metal, and plastic containers. In some areas, drop-off bins are provided at appropriate locations in the community and at retail deposit return sites. Recycling co-ordinators ask that container caps be removed and the bottles rinsed before being placed in a collection bin.
Commingled collection systems have proven to be the most efficient. In this method, the consumer simply places all recyclable containers in a common bin for pickup and delivery to a Materials Recovery Facility (MRF). The MRF subsequently separates and prepares the containers for sale to a recycling firm.
For any collection program to succeed, consumers must become educated and motivated so that identification and collection of recyclable containers becomes a routine activity. Most consumers readily recognise PET soft drink bottles. However, the use of PET has expanded rapidly into other areas such as containers for water, sports drinks, food products, alcoholic beverages, household products, and cosmetics. Accordingly, it becomes vital that consumers understand and use the codes for proper identification of recyclable containers. Educational programs, such as NAPCOR's "Look Out for Number One" campaign, are a must if consumers are to become properly informed and motivated.
The educational effort is a key factor in the practice of good product stewardship, and several organizations including NAPCOR, PETCORE, APREPET, and PLASTIVIDA have risen to the challenge. Educational materials are available from these groups for general distribution to the public.
Cleaning and Separation
Once collected, containers are forwarded to recycling locations where they are run through grinders that reduce them to flake form. The flake then proceeds through a separation and cleaning process that removes all foreign particles such as paper, metal, and other plastic materials.
Having been cleaned according to market specifications, the recovered PET is sold to manufacturers who convert t into a variety of useful products such as carpet fibre, strapping, moulding compounds, and non-food containers.
There are about three dozen recycling companies in operation, two-thirds of which are located in North America. These plants have the cleaning and separation technology to convert post-consumer bottles to flake for sale to end users. Their total capacity approaches together 436 thousand tonnes (960 million lb) on a three-shift basis - evidence that there is capacity available to handle the growing demand for recycled PET.
The recycler is the vital link between the collection process and the end users having need of the recycled resin. Industry associations also play a valuable role by bringing communities and recycling outlets together.
|Use for Reclaimed PET|
About three-fourths of reclaimed PET is used to make products such as
fibres for carpets, fibrefill, apparel and geotextiles. Much of the
remainder is extruded into sheet for thermo-forming, stretch blow-moulded
into non-food containers, or compounded for moulding applications.
The chemical process for producing PET can be reversed by two commercially available depolymerisation methods - methanolysis and glycolosis.
These processes subject clean flake to a chemical reaction that reduces it to either a monomer or the original raw materials. These materials can then be purified and subsequently re-reacted into "new" PET for use in food-contact applications.
In some countries, reclaimed PET is used for food packaging by incorporating it into the core layer of a three-layer sandwich structure or by subjecting it to special cleaning processes.
|When PET is Burned for Energy Recovery|
Many communities send their trash to state-of-the-art, waste-to-energy
incineration facilities, reducing the volume of waste going to landfills
by as much as 90%. As stated earlier, incineration for energy recovery
accounts for 17% of all solid waste disposal in the United States.
In Europe, the percentage is 30%, with Switzerland burning about 80%. As shown below, plastics have an inherent energy value higher than any other material commonly found in the waste stream.
|When PET Containers are Landfilled|
While a growing number of PET containers are being recycled and others are
being incinerated, some inevitably find their way into landfills. What
happens to these containers? Virtually nothing. They contain no noxious
components that might leach into underground water supplies, nor do they
decompose. Landfill digs, conducted by noted professor of archeology Dr.
William Rathje, indicate that many landfilled items, including some foods
and paper, remain virtually unchanged for decades.
Since very little decomposition takes place in a modern landfill, such sites are, in effect, solid waste repositorios. Consequently, landfills simply fill up, with little or no decomposition taking place. Hopeftilly, fewer and fewer PET containers will go into landfills. However, those that do will be crushed to their minimum size, and their inert nature will not negatively impact the landfill.
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