Recycling codes, for plastic

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. 

Section B lists, in alphabetical order, the abbreviations and acronyms for thermoplastics, thermosets, fibers, elastomers, and additives. Sections C and D list the abbreviations for polymers, based on their monomeric imits and characteristic groups, respectively. Section E contains abbreviations and acronyms for polymers obtained by chemical transformation of base polymers. Section F contains special abbreviations for blends, reinforced polymers, etc., and Section G the ISO and DIN codes for plastics. Section H lists the special abbreviations connected with the recycling of plastics. Recommended abbreviations and acronyms for elastomers and fibers are given in Sections I and J, respectively. 

To aid recycling, the Society of the Plastics industry has issued numeric codes to identify the plastic used in fabricated articles. Each article should have an imprint of a triangle which encloses a number identifying the plastic used in its fabrication. LDPE (and LLDPE) are indicated by the number 4 and HDPE by the number 2. Codes for polyethylene and other plastics are shown in Figure 8.10. 

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... 

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

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). 

Apple Computer has banned the use of various chemicals in its products, including PB-DEs. It prohibits any PVC parts or packaging of more than 25 g, except for closures for cables and wires. Several of its computers use recyclable polycarbonate for the enclosure. Large mechanical plastic parts are made of a single material or of compatible materials and marked with resin identification codes to facilitate recycling. ... 

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. 

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). 

You can identify the type of polymer used to manufacture a plastic item by looking for the recycling symbol (arrows in a triangle) found on the label or on the bottom of the plastic container. For example, either the number 5 or the letters PP inside the triangle is a code for a polypropylene plastic. Many cities now maintain recycling programs that reduce the amount of plastic materials that are transported to landfills. 

One of the obstacles in the recycling of different types of plastic is their separation and recently manufacturers have started determining the type of plastic using the numerical coding system developed by the Society of Plastics Industry in the 1980s. Table 1.1 summarises the identification code for some household applications [3]. 

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. 

Manufacturers produce more than 8 billion pounds of BPA every year, making it one of the most common industrial chemicals produced worldwide (Rubin 2011). Plastics made with BPA are used in many consumer products, including food and beverage containers, toys, eyeglasses, computers, kitchen appliances, and medical equipment. Epoxy resins containing the chemical are used in dental work and in metal coatings for food cans, pipes, cars, dairy equipment, office equipment, and other metal products. BPA and its derivatives are also used in flame retardants (tetrabromobisphenol A), in engineering applications such as laminates for printed circuit boards, and as color developers in thermal receipt paper (Birnbaum et al. 2012). Some, but not all, plastics that are marked with recycle codes 3 or 7 may be made with BPA. 

Identification of the materials of construction (i.e., plastics, paper, metal, glass, elastomers, coatings, adhesives, and other such materials) should be identified by a specific product designation (code name and/or code number) and the source (name of the manufacturer) alternate materials of construction should be indicated postconsumer recycled plastic should not be used in the manufacture of a primary packaging component, and if it is used for a secondary or associated component, then the safety and compatibility of the material for its intended use should be addressed appropriately... 

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