Codes, plastic recycling

Other than for incineration and some of the newer chemical recycling technologies, sorting of plastic waste into polymer types is of fundamental importance. In order to make separation easier for the consumer an international plastic recycle code mark is printed on larger items (Table 2.3). Even small amounts of a mixed plastic (sometimes as low as 1%) can have significant detrimental effects on the properties of a recycled polymer and result in it needing to be used in low-value applications. 

Nor is it tme that poly(ethylene terephthalate) (PET) and high density polyethylene (HDPE) packaging are hsted as 1 and 2 in the Society of the Plastics Industry (SPI) recycling coding system because they are the most recyclable. The numbers assigned to each plastic in the SPI coding system are purely arbitrary and do not redect the material s recyclabihty. 

Once a consumer has purchased a material made of a polymer, the likelihood of it being recycled is dramatically reduced. In the United States there are three resins that are commonly recycled polyethylene, polypropylene, and polyethylene terephthalate, SPI (The Society of the Plastics Industry) recycling codes, found on the bottom of food containers, provide the consumer with information as to the recyclability of the material. Table 17,1 lists these codes. 

Society of Flavor Chemists, Inc., 11 563 Society of Rheology nomenclature, 21 704 Society of the Plastics Industry, The (SPI) on PVC recycling, 25 680 recycling coding system of, 25 681 Sociopolitical dimensions, of sustainable development, 24 189—190 Socks (mid-calf)... 

FIGURE 1.1 The Society of Plastics Industry recycling codes utilizing the numbers 1-7 and bold, capital letters to designate the material utilized to construct the container. 

Only Codes 1 and 2 are widely accepted for recycling. Codes 3 and 6 are rarely recycled. Find out what types of plastics are recycled in your area. If you know what the codes... 

What do the recycling codes on plastic products indicate ... 

Recycling code Type of plastic Physical properties Examples Uses for recycled products... 

Find three plastic objects in your home that are labeled with a recycling code of 1. From what substance are these objects made Are objects of this type recycled in your town ... 

To find out more about types of plastic, resin codes, and how plastic is recycled, check out the following Web links from the National Plastics Council and the National Association of PET Container Resources www.americanplasticscouncil.org and www.napcor.com/codes.htm. 

The popularity of clothing made of polyester-cotton blends testifies to the economic impact of this polymer. Poly(ethylene terephthalate) is the PETE referred to in the recycling codes listed in Table 27.1. Plastic bottles for juice, ketchup, and soft drinks are usually made of PETE, as is Mylar film (Figure 27.8). 

FIGURE 14.14 Plastic container codes, used to identify types of plastic so that containers can be sorted for recycling. 

Table 4.7 Annual world production and recycling codes of the most important plastics...

Origin Plastic (abbreviation) Estimated world production (million t, 2008) Recycling code(s)... 

The numeric coding of six popular types of plastic by the Society of the Plastics Industry (PET - 1, HOPE - 2, PVC - 3, LDPE - 4. PP - 5, and PS - 6) with subsequent acceptance of such number coding of containers into law by a number of stales across the country has made post-consumer plastics recycling more prevelant than ever. 

Six types of plastics are commonly used for packaging apphcations. In 1988, manufacturers adopted recycling code numbers developed by the Society of the Plastics Industry (Table 16.2). Because the plastics recycling industry stiU is not fully developed, only PET and HDPE are currently being recycled in large quantities. LDPE, which accounts for about 40% of plastic trash, has been slow in finding acceptance with recyclers. Facilities for the reprocessing of poly(vinyl chloride) (PVC), polypropylene (PP), and polystyrene (PS) exist but are rare. 

Your instructor may ask you to bring a polymer sample of your own choice. If possible, these samples should be clear and as thin as possible (similar to the thickness of plastic sandwich wrap). Good choices of plastic materials include windows from envelopes, plastic sandwich wrap, sandwich bags, soft-drink bottles, milk containers, shampoo bottles, candy wrappers, and shrink-wrap. If necessary, the samples can be heated in an oven and stretched to obtain thinner samples. If you are bringing a sample cut from a plastic container, obtain the recycling code from the bottom of the container, if one is given. 

You can use the essay "Polymers and Plastics" and Technique 25 with your spectrum to help determine the structure of the polymer. Most likely, the polymers will consist of plastic materials listed in Table Three of the essay. This table lists the recycling codes for a number of household plastics used in packaging. Submit the infrared spectrum along with the structure of the polymer to your instructor. Do your spectrum and structure agree with the recycling code Label the spectrum with the important absorption bands consistent with the structure of the polymer. 

Polyethylene terephthalate and HDPE bottles continue to comprise over 96% of the United States plastic bottle market. In 2011, the total annual post-consumer plastic bottles recycled in the United States increased to an all-time high of 2624 million pounds. The total bottle collection rate was 28.9% for 2011. Plastic bottles with recycling codes 3 to 7 makeup only 3.5% of the plastic bottle market. Of these bottles, polypropylene bottles were recycled at a rate of 2.2% and PVC recycled bottles were recycled at a rate of 0.8% in 2011 (Association of Postconsumer Plastic Recyclers and the American Chemistry Council 2011). 

The plastic materials can be collected and sorted based on the Society of Plastics Industry (SPI) recycling code. The recycling code was created in the late 1980s. The recycling code can help keep the recycled plastics segregated by plastic type. Then, waste management companies can sort the plastics into bins of each recycled plastic. 

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