Recycling

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Demand for consumer products is rapidly growing throughout the world. New markets are opening in developing countries, which is causing a rapid build-up in their production capacities. The accelerating demand for energy and resources to meet the market buildup threatens to be environmentally unsustainable, as well as economically and socially destabilizing, unless manufacturing procedures shift to embrace new processes and feedstocks that minimize the production footprint. Recycling is critical as the foundation for sustainable production.

[edit] Ideal Recycling Program

Recycling programs are developed to enhance public interest goals for conserving natural resources, water and energy, strengthening environmental quality and reducing climate change. So a good community recycling program should:

implement recycling as a resource management system, not a waste management system. The community should look to return the collected materials to manufacturers who will make products that are continuously recycled and reduce the need for extraction of raw materials. If a recycling program’s only goal is diversion, then any of the different uses for recyclable materials is equivalent to all the others. But if diversion goals are combined with requirements for maximizing recycling benefits, then it becomes clear that using mixed paper to make shingles moves only one step away from the landfill, while sorting the paper so it can be used for printing and writing papers generates up to a dozen times the environmental savings. Municipal governments should not pour billions of dollars and enormous resources into creating and maintaining their recycling programs just to get one step away from the landfill. When recycling programs ensure that enough high quality recovered materials are available to make products that can be repeatedly recycled, the conservation and environmental benefits are multiplied, the volume of recovered materials available is extended to its maximum, and recovered materials are then available to support all levels of recycled product manufacturing.
have significant and continuous public education drive as well as simplify its list of collectable and noncollectable materials. Residents should be asked to separate for recycling only those materials that can successfully be marketed. And use the terms the public uses to describe materials, not technical jargon. Not only do residents need to know what to collect and how to prepare the materials, they also need to know how well they are doing. Feedback can tell them when their participation needs improvement and how to do it. A public that understands how best to participate in their recycling program supports the success of both the collection and processing systems.
have a collection requirement against the disposing public. For example, a different recyclable or material for each colored bin or cart and noncollection on noncompliance of clean segregation requirement.

Materials that can easily be collected and processed include:	Materials that are generally not collected include:
Dry clean fiber such as: corrugated containers, newspapers, mixed paper, office paper, white ledger	Soiled and food-contaminated papers except sometimes in composting operations
Aluminum and steel/tin cans	Any metal items bigger than a large tin can
Glass and plastic bottles and jars	Any glass that is not a bottle or jar (e.g. Pyrex™ and other glass cookware, plate glass, drinking glasses and mirrors, which are serious contaminants for glass beverage container furnaces)
	Ceramics
	Rocks and stones
	Mixed material items (such as toys)
	Garbage
A wide range of materials do not fall into either of the above two categories. Many of these items (such as scrap metal, film plastics, textiles, and dry cell batteries) can be recycled if the processing system is designed to handle them and if there are markets available to the local community. Additionally, items such as electronics, paint, and hazardous wastes may be recovered if processing technology and markets are available, but they are not generally compatible with a single stream recycling program.

have specific quality requirements set out in the contracts with collectors and processors.
include specific contractual reporting requirements for collectors, such as noncollections due to collection requirement violation, and processors, such as recovery rates and output by material grade.
Put out competitive bidding for contractor work. Local governments must identify the services that they wish to have provided and not simply accept what a contractor says it is willing to provide. Communities should pay the processor to produce the quality materials that meet the manufacturing industry specifications.
collect recyclable materials for which available markets exist.
have established arrangement with recycled product manufacturers, especially with high value recyclable buyers, to set collection and processing standards and targets.
match the types of collected materials with the capability of the material recovery facility.
separate collection for commercial and residential sources as well as their separate processing. For example, offices will have more white paper and less newspaper than a residence. If the white paper is not separated from the residential mixed paper, this high value material may be lost to the white paper market, decreasing the ability of paper manufacturers to provide recycled content in printing and office papers, and tissue products.
have a separate collector for each category of material (e.g. each type of recyclable, garbage, greenwaste, foodwaste), or if a split-body truck is to be acquised, calculate the relative proportions of each material before ordering the vehicles.
avoid high truck-compaction rates to make it easier for sorting and preserve marketability of materials. This is especially important to glass recyclables. It is important to minimize, if not avoid, glass breakage during and after collection.
sample the quality of collected loads when they reach the processor, in order to identify and address collection problems as early as possible.
have a feedback mechanism for processor to comment and suggest improvements about the collector's quality of materials, partcularly on [[Recycling#Collectable Materials|material contamination].
incentivize collection efforts that provides clean loads/inputs and penalize contaminated ones.
estimate a daily quantity of materials to process. Process no more material than it can handle appropriately with in the time provided. Maintain appropriate burden depth on conveyor belts to ensure quality sorting.
have the right types and sizes of processing equipment.
have enough personnel, sorting stations and storage bunkers and allow for excess capacity during volume spike and for future expansion. Sufficient storage space can help prevent the urge to overburden conveyor belts and other equipment and allow consistent high quality processing even when truck deliveries are much heavier at some times than at others.
prevent contamination of recyclables.
process each type of recyclable material to correspond with buyer specifications. Properly separate each recyclable into marketable grades and remove contaminants (nonrecyclables). Receiving poorly sorted materials from a processor discourages manufacturers from investing in new or expanded recycled product manufacturing capacity and even may cause some to close or return to using raw virgin resources. Low quality recovered materials can lead to defects in finished products, which threaten buyers’ acceptance of recycled products.
process materials in a sequence that will maximize the quality of the recovered materials.
have material recovery facilities that aim to maintain the grade of their output. The materials sold by the processors are feedstocks for manufacturing processes and they should meet high quality standards.High quality sorted materials can be sold to a wide diversity of markets and support the whole range of products that can be made with recovered materials. Many sorted materials can be directed into products that can be recycled multiple times, producing conservation benefits and savings many times over.
properly handle contaminants and non-targeted recyclables.
incentivize shipping of clean materials and financially penalize for contaminated shipments.
be able to upgrade processing facility to increased material type collection.
know the fate of each of the materials being shipped from the processor and know how much material are actually usable. Manufacturers can provide reports on “millage loss” to processors and community recycling program managers.
have continuous communication with buying manufacturers, especially concerning market residue (i.e., materials that are shipped but for which the manufacturer do not have use) and when developing plans for a new MRF or redesigning the recycling program.
have adequate funding for the level of quality output desired.
avoid use of recyclables for low-value uses, such as roadbeds or burning for energy.
cost-effective.

Recycling is an interdependent network, in which success or failure in one sector reverberates into all others. If recyclable materials are not collected, manufacturers do not have the feedstocks they need to make new recycled content products. If collected materials are contaminated or poorly processed, manufacturers cannot make high quality products from them and may even lead to closure of recycling production. If manufacturers do not buy recovered materials, collectors and processors have no markets and recyclables must be landfilled. If consumers do not buy recycled products, manufacturers have no incentive to continue making them and then, again, collectors and processors have no markets. If consumers contaminate recyclables, then they will not be able to be made back into new products.

[edit] Typical Recyclable Processing

Generally, as trucks arrive at the MRF, they are weighed to provide data on the total amount of recyclables that are received. The material in the truck should be sampled at this point to determine the composition, including the amount of “prohibitives” in the load.
The trucks then proceed to the tipping floor, generally a concrete pad, where the truck is unloaded. Minimizing or cushioning the drop at the MRF can help maintain glass quality.
Once the truck has pulled away, the recyclables are pushed up into a large storage pile using a wheeled bucket loader. This step often degrades the recyclables by mixing crushed glass into all of the materials in the load. It is best to avoid pushing the materials to a pile.
At some facilities, some prohibitives (such as hazardous materials like household cleaners), hard to process materials (such as wire, garden hose and tires), and oversized items (such as large pieces of cardboard and boxes) may be removed from the load before the materials are pushed into the general storage pile. It is also best to get the glass out from the stock at this point. It also helps to separate the breakable contaminants (Pyrex™, heat sensitive glass, ceramics and rocks) from the bottle glass. Once the glass has been directed away from the other materials, sort it by color to increase its market value.
The loader is then used to take recyclables from the storage pile and load them onto a conveyor belt that carries them to the first processing stations. Because of the size of the bucket on the loader, the volume of materials arriving at the processing line tends to be inconsistent, with large surges followed by blank space. New load leveling devices have recently been developed.
Most designs remove large items first, such as corrugated boxes, so that smaller items can be exposed for later sorting. In some facilities, workers often do the initial processing by picking selected materials off the belt as they come by. In more highly capitalized and newer facilities, screens are used as the first processing tools to separate the largest materials, such as boxes that pass over the disks, from other materials that pass through the openings in the screens (between the disks).
An increasingly common facility design is to smash the glass at the beginning of the processing system, as the materials flow onto the screens, so that most of the glass can be removed from the paper. However, this often makes it impossible to sort the glass to a high enough quality to be used to make new bottles.
Modern screens may have two or three stages that separate multiple material types, so that the recyclables that pass through the cardboard screen will be further separated into large sheets of paper (e.g. newsprint) and other materials (e.g., beverage containers). The third screen may separate the rest of the paper (e.g. high grade sheets and bulk mail) and film plastic bags from containers.
The container stream is passed under a magnet to remove the steel/tin cans, then sorted by density to separate glass from plastic and aluminum cans. Once the glass is separated from the aluminum and plastics, it can be sorted by color using an optical sorter; and optical sorters can separate plastics by type, or separate plastics from other materials.
Small item fractions on the conveyor belt are screened to remove the fines (tiny fragments of materials). They may become part of the facility residue or may be further processed to separate light materials (e.g. shredded paper) from heavier ones (e.g. glass, ceramics, rocks), so that additional recyclables can be recovered.
Garbage is either picked off the belt as a positive sort (if the load was relatively clean) or becomes residue that is allowed to go off the end of the belt as a negative sort. The residue is then delivered to a landfill.
Sorted recyclable materials are baled for transport to manufacturers or to other facilities for further processing. Some are loaded loose into trucks (e.g. glass and sometimes newsprint), depending on specific market requirements. Partially sorted materials also may be shipped to other facilities for further processing, such as glass to beneficiation plants, plastics to facilities that can sort by resin type, and paper to facilities with optical scanners to sort by grade. There are times when it is beneficial to send processed materials back through the sorting lines again in order to clean them to a higher quality level. But frequently it passes through an intermediate temporary storage area.

Large processing facilities primarily use mechanical and optical sorting instead of manual sorting to increase throughput and efficiency, and to produce a more consistent marketable commodity from the materials received. (Equipment manufacturers rate their equipment on the basis of sorting under optimum conditions, so they present maximum capacity numbers.) Machinery, while initially expensive, ultimately lowers the cost of processing per ton of materials as long as it is appropriate for the volume of materials processed. At the same time, MRFs cannot run effectively without enough manual labor for equipment maintenance, making sure that the equipment is operating properly, and hand-sorting some materials.

[edit] Recycling and Industries

Recyclables can often be used for making several different kinds of products, including:
Products that require well-sorted materials and can continue to be recycled many times, such as newsprint, printing and writing paper, glass and plastic bottles, and metal cans. These high quality, well-sorted materials usually have the greatest versatility within their industry’s markets, as well.
Products that require well-sorted, high quality materials but are impossible or unlikely to be recycled, such as glass used to make fiberglass.
Products that can use commingled materials and that can be recycled, but only into similar products. For example, paperboard boxes and corrugated medium (the fluted layer in the middle of corrugated boxes) both can use commingled fibers and both can be recycled. But once the commingled fibers have been used in these products, they cannot be sorted back into grades suitable, for example, for making office paper or newsprint grades. While office papers and newsprint can be “down-cycled” to make paperboard and medium, the resulting products cannot “up-cycle” into grades that require sorted fibers, thereby reducing the capacity for incorporating recycled content into products such as newsprint and printing and writing grades.
Products that can use commingled materials and are durable and/or unlikely or impossible to recycle. Plastics can be commingled to make plastic lumber, paper can be commingled to make shingles and notepad backings, glass can be crushed unsorted for roadbeds or landfill daily cover. While these can be good uses for some of the materials, when they are the first destination for recyclables, all the other potential subsequent recycling uses are eliminated.
Products that are made to be used only once. The most environmentally responsible choice for many tissue products, for example, is recycled content, even though their purpose precludes their reuse. Other one-time-use products may not play such a necessary role, and yet take recyclable materials out of the markets permanently.

[edit] Paper Industry

Paper fiber may be in the form of newspapers, magazines and catalogs, phone books, office paper, mail, containers such as milk cartons, and packaging such as cereal boxes or corrugated cartons. Each type of paper product is made in a different type of paper mill and each of those types of mills needs a specific type of fiber. Fibers incompatible with specific types of mills, such as corrugated boxes at a newsprint mill or old newspapers at a mill that makes printing and writing papers, can create product defects and, if they can be separated from the incoming materials, are usually landfilled.
Glass in the fiber bales endangers paper mill workers, is abrasive and damaging to expensive paper manufacturing machinery, and can end up in finished products. When glass goes into the paper mill’s pulper, some of it is removed by the action and screens in the pulper and is piped away for disposal. But some of it is so fine that it is forced through the cleaning screens, even though the slots in the screens may be no more than 1/6,000 of an inch. Moreover, as pulp travels through many types and sizes of screens on its way to the papermaking machine, glass grinds up the screens and makes the holes in them larger, reducing their effectiveness. Glass can end up in the final paper products and damage equipment at printing and packaging plants. Luckily, paperboard mills use a different type of pulping unit than with newsprint mills and can get most of the glass out of their system.
Many of the surfaces in papermaking equipment need to be completely smooth to make uniform high quality products that will later perform perfectly on customers’ equipment. The glass scrapes and scratches these surfaces, requiring them to be resurfaced more frequently and increasing plant downtime while they are switched out.
Linerboard mills, which make the outer layers of corrugated boxes, cannot use newsprint or office papers to make their products because the fibers from these materials do not provide enough strength. Newsprint mills cannot use corrugated boxes, and printing and writing mills cannot use either newsprint or boxes. But paperboard mills and those that make the fluted center of corrugated boxes can take a wide range of mixed materials.
A paper mill making the inner lining for corrugated boxes (medium), shingles, and stiffening board products such as notepad backings and binder construction can take a wide range of mixed papers. Mixed fibers cannot be used to make newsprint, tissue products, printing and office papers, corrugated linerboard (the outside layers of corrugated boxes), or the printing surfaces for paperboard boxes (such as cereal boxes).
Many paper mills, both domestic and overseas, are adding processing equipment to their facilities in order to offer some protection to their manufacturing equipment, which usually is valued in the hundreds of millions of dollars. But this represents a failure by the processing sector.

[edit] Plastics Industry

The seven primary types of plastics represented by the chasing-arrows plastics numbering system actually result in over 15 material types for recyclers, if they are to be recycled into their highest value products. But because the cost of sorting plastics is so high, many may be combined to make lower value (mixed type, mixed color) products such as ocean pier pilings. While these are often excellent candidates for recyclable materials, they cannot be recycled again into new products.
Once plastics have gone through the paper mill’s pulping system, they are no longer appropriate for plastics recycling and must be landfilled.
Glass mixed with plastics cause worker hazards, grit that grinds up the manufacturing equipment, and holes in products.
Small finer mixed with plastics increase the cost of washing and drying the recovered plastic.
Some plastics facilities making plastic lumber can take a wide mix of plastics. However, other recycled content plastics products such as fiberfill, carpets, and plastic bags require a single type of plastic resin and cannot use others.

[edit] Glass Container Industry

Glass can be infinitely recycled, unlike other recyclables that degrade as it reenters the cycle. But when glass is broken too fine, its recycling life cycle is cut short when it is used for roadbeds or similar low-value uses. Material that goes off for this kind of very low grade “beneficial reuse” should also not be counted as “recycled.”
Contaminants such as heat-sensitive glassware (e.g. Pyrex™) and ceramics, stones, rocks and dirt that can no longer be adequately removed once the glass is broken into small pieces and these fines cause imperfections to products and are therefor landfilled.
Organics and plastics cause the glass to froth, or vary, in color as well as cause problems within the furnace.
Once glass has gone through the paper mill’s pulping system, it cannot be separated for recycling into new containers or other high value products.
Some fiberglass manufacturers can use crushed mixed glass, even with ceramics that would be contaminants for a glass bottle manufacturer.
Using recycled glass containers for making new glass containers allows the manufacturer to operate at a lower furnace temperature, reducing air pollution and requiring less fuel.

[edit] Overall

What is good material for one type of mill may be a contaminant for another type of mill.
The number of mills that can use these commingled mixes is quite small compared to the much larger number of manufacturers that require separated and high quality materials. Communities that rely primarily on markets that accept commingled materials limit their options, particularly as more programs offer commingled materials to the same markets. High quality and well-sorted materials will always have flexible access to markets, no matter whether they are up or down.
If a recycling program’s only goal is diversion, then any of the different uses for recyclable materials is equivalent to all the others. But if diversion goals are combined with requirements for maximizing recycling benefits, then it becomes clear that using mixed paper to make shingles moves only one step away from the landfill, while sorting the paper so it can be used for printing and writing papers generates up to a dozen times the environmental savings. Municipal governments should not pour billions of dollars and enormous resources into creating and maintaining their recycling programs just to get one step away from the landfill. When recycling programs ensure that enough high quality recovered materials are available to make products that can be repeatedly recycled, the conservation and environmental benefits are multiplied, the volume of recovered materials available is extended to its maximum, and recovered materials are then available to support all levels of recycled product manufacturing.