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Introduction
The McGraw-Hill Recycling Handbook: 2nd Edition
Herbert F. ...
“Despite the technological progress in automated sorting systems, there are not currently any high-speed automated sorting systems that can distinguish between grades of plastics within the same resin type-manual sorting is still required to separate these different products from each other.”
Background and Importance of Plastics
- polymer overview (11)
Plastics: The Basics
Plastics are polymers. ... You generally think of crystalline structures in salt and gemstones, but not in plastics. ... This property allows for easy processing and facilitates recycling. ... Plastics can be molded into bottles or the bodies of a cars or be mixed with solvents to become an adhesive or a paint. Elastomers and some plastics stretch and are very flexible. ... html
- Alternative packing material
- energy savers (13)
An option for plastics that are not recycled, especially those that are soiled, such as used microwave food wrap or diapers, can be a waste-to-energy system (WTE). ... The heat energy produced by the burning plastics not only can be converted to electrical energy but helps burn the wet trash that is present. Paper also produces heat when burned, but not as much as plastics. ... html
Recycling Concerns
- overview of plastics recycling
Encyclopedia of Environmental Science & Engineering 4th Ed
Edited by James R. ... Zieger
1992 OPA
“The plastics have, however, added significantly to the volume of waste, and have made waste management more difficult.”
“the US Environmental Protection Agency estimates that the weight percentage of plastics in municipal solid waste is about 7-9% but this material occupies 25-30% of the total waste volume.”
“it is expected that recycled plastics prices will stabilize at 80-90% of those for virgin materials.”
“A major problem in plastics recycling is the low weight-to-volume ratio. ... ”
“PET and HDPE are the plastics most commonly collected for recycling from municipal solid waste and inclusion of polyvinyl (PVC) bottles is not desirable. ... ”
“at present the overall recovery rate for plastics is about 1-2%”
The McGraw-Hill Recycling Handbook: 2nd Edition
Herbert F. ...
“Some states have sought to increase plastics recycling rates by passing demand-side legislation that mandates that manufacturers use certain recycled content levels for some products. While these actions have certainly increased the demand for some types of recycled plastics, they have done little to divert more plastics from disposal.”
“The bottom line for plastics is that the level of market demand or scrap prices paid has little impact on postconsumer plastics recycling rates. ... ”
“Different types of plastics resins are also made from different precursors, and are different on the molecular leve. These molecular differences cause most plastics to be incompatible with other plastic types when melted together; they tend to separate much like oil and wate rseparate when mixed together. For these reasons, different types and grades of plastics look alike and behave alike because they are chemically identical or have similar physical properties (such as density). ... Little
“Recycling is valued for: conserving natural resources, creating jobs and additional economic activity, reducing the environmental impacts of virgin material extraction.”
“Though plastics constitute nearly one-fourth the volume in landfills, so far only about 7% of new plastic products (by weight) are made from recycled materials.”
“The reasons for this are the low cost of petroleum, from which plastic feedstocks are derives, and the high cost of segregating the many different types of plastics in the waste stream prior to remanufacturing.”
“Ordinary plastics persist for 200-400 years, and even the new biodegradeable products an last several decades. Many experts believe that the use of plastics as throwaway containers should be severely curtailed.”
The McGraw-Hill Recycling Handbook: 2nd Edition
Herbert F. ...
“Plastics packaging comprisese 12% of all packaging”
“Most plastics that are recycled come from the thermoplastic family of plastics, which represents about 90% of all plastics sold. ...
“Thermosetting plastics do not melt when heated.”
“The entire spectrum of packaging plastics is thermoplastic. ... Liptak (Handbook Editor)
CRC Press
LLC 2000
“Plastics generate toxic by-products when burned and are nonbiodegradable when landfilled.”
“In addition, plastics foul the ocean and harm or kill marine mammals. Other problems include the toxic chemicals used in plastics manufacturing, the reliance on nonrenewable petroleum products as their raw material, and the blowing agents used in making polystyrene foam plastics, such as chlorofluorocargons (CFCs), which cause ozone depletion. ... For these reasons, recycling appears to be the natural solution to the plastic disposal problem.”
From: “Improvements in the properties of mechanically recycled thermoplastics”
“The main motivations to undertake mechanical recycling are the possibilities of reducing:
- landfill space requirements
- emissions from waste incineration
- consumption of non=renewable resources
costs for production of new products”
A review of plastics waste recycling and the flotation of plastics
“The growth of plastics waste has a great impact on the management of MSW by landfilling and incineration, because available capacity for landfill of MSW is declining and plastics incineration may cause emissiona dn toxic fly and bottom ash which contain lead and cadmium.”
- reasons not to recycle (5)
From: “Improvements in the properties of mechanically recycled thermoplastics”
“There are several trends that are discouraging the mechanical recycling of plastics. The prices of virgin plastics are currently relatively low, and plastics processing machinery is becoming more and more sophisticated in order to reduce raw-material requirements, raise throughputs, and cut cycle times. ... ”
The McGraw-Hill Recycling Handbook: 2nd Edition
Herbert F. ...
“Every time plastics are melted, they degrade to some extent. Some types of postconsumer plastics, such as PET, can be rejuvenated through a “solid-stating’ process to restore the recycled resin to virgin-equivalent properties. ... ”
“Some types of plastics, such as PET and nylon, can be recycled through a depolymerization process in which the plastic is broken down to its basic building blocks, calle dmonomers. ... This process offers the greatest promise for unlimited recycling of plastics back into virgin=-equivalent resins. ... ”
- applications of recycled plastics
Applications for recycled plastics are growing every day. Recycled plastics can be blended with virgin plastic (plastic that has not been processed before) to reduce cost without sacrificing properties. ... Recycled plastics are used to make polymeric timbers for use in picnic tables, fences, and outdoor toys, thus saving natural lumber. ... html
The McGraw-Hill Recycling Handbook: 2nd Edition
Herbert F. ...
“The APC has identified over 1400 products made with recycled plastics. ... reclaimers for high-quality recovered plastics and play a significant role int eh overall market. Export markets also source mixed or lower grades of plastics for which there ar elimited domestic markets.”
“Health and safety concerns limit the products that plastics are recycled into, and little recycled plastic is returned to food or beveraged container use. ... Plastics, however, are produced at much lower temperatures and are permeable to some chemicals. ... These contaminated containers may be introduced into the recycling system. ... Some virgin plastics (including certain grades of PET and HDPE) are not refined to high purities because they are not intended to come into contact with food. Containers made from these plastics are often included in recycling systems. ... ”
“The recycling of a particular type of plastic product should be environmentally and economically responsible and sustainable.”
“Recycled postconsumer plastics must compete with preconsumer recycled plastics and virgin plastics in terms of both price and performance. ... ”
“Because plastics are essentially energy (natural gas and oil) embodied in solid form, with more BTU value than coal, there are diversion opportunities for recovering energy from them rather than putting them in a landfill. ... , a leading practitioner in life cycle studies, has conducted research to compare the life cycle energy impacts of plastics and alternative materials. ...
Plastics can also help conserve energy in your home.
Approximate Word count = 6347
Approximate Pages = 25.4
(250 words per page double spaced)
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