Scrap or Waste Plastics Recycling is the process of recovering and reprocessing the material into useful products, sometimes completely different from their original state. For instance, this could mean melting down polyester soft drink bottles then making model army figures and ammunition.
Plastics are durable and degrade very slowly. In s ome cases, burning plastic can release toxic fumes. Also, the manufacturing of plastics often creates large quantities of chemical pollutants.
To assist recycling of disposable items, the Plastic Bottle Institute of the Society of the Plastics Industry devised a now-familiar scheme to mark plas tic bottles by plastic type। A recyclable plastic container using this scheme is marked with a triangle of three "chasing arrows"।
which encloses a number giving the plastic type:Plastics are durable and degrade very slowly. In s ome cases, burning plastic can release toxic fumes. Also, the manufacturing of plastics often creates large quantities of chemical pollutants.
By the 1990s, plastic recycling programs were common in the United States and elsewhere. Thermoplastics can be remelted and reused, and thermoset plastics can be ground up and used as filler, though the purity of the material tends to degrade with each reuse cycle. There are methods by which plastics can be broken back down to a feedstock state.
To assist recycling of disposable items, the Plastic Bottle Institute of the Society of the Plastics Industry devised a now-familiar scheme to mark plas tic bottles by plastic type। A recyclable plastic container using this scheme is marked with a triangle of three "chasing arrows"।
1. PET (PETE), polyethylene terephthalate: Commonly found on drink/cooking oil bottles and peanut butter jars.
2. HDPE, high-density polyethylene: Commonly found on detergent bottles, milk jugs.
3. PVC, polyvinyl chloride: Commonly found on plastic pipes and liquid detergent containers.
4. LDPE, low-density polyethylene: Commonly found on dry-cleaning bags and containers.
5. PP, polypropylene: Commonly found on bottle caps, drinking straws, yogurt containers.
6. PS, polystyrene: Commonly found on "Styrofoam peanuts".
7. OTHER, other: This plastic category, as its name of "other" implies, is any plastic other than the named #1–#6.
3. PVC, polyvinyl chloride: Commonly found on plastic pipes and liquid detergent containers.
4. LDPE, low-density polyethylene: Commonly found on dry-cleaning bags and containers.
5. PP, polypropylene: Commonly found on bottle caps, drinking straws, yogurt containers.
6. PS, polystyrene: Commonly found on "Styrofoam peanuts".
7. OTHER, other: This plastic category, as its name of "other" implies, is any plastic other than the named #1–#6.
Unfortunately, recycling plastics has proven difficult. The biggest problem with plastic recycling is that it is difficult to automate the sorting of plastic waste, and so it is labor intensive. Typically, workers sort the plastic by looking at the resin identification code, though common containers like soda bottles can be sorted from memory. Other recyclable materials, such as metals, are easier to process mechanically. However, new mechanical sorting processes are being utilized to increase plastic recycling capacity and efficiency.
While containers are usually made from a single type and color of plastic, making them relatively easy to sort out, a consumer product like a cellular phone may have many small parts consisting of over a dozen different types and colors of plastics। In a case like this, the resources it would take to separate the plastics far exceed their value and the item is discarded. However, developments are taking place in the field of Active Disassembly, which may result in more consumer product components being re-used or recycled. Recycling certain types of plastics can be unprofitable, as well. For example, polystyrene is rarely recycled because it is usually not cost effective. These unrecyclable wastes can be disposed of in landfills, incinerated or used to produce electricity at waste-to-energy plants.
While containers are usually made from a single type and color of plastic, making them relatively easy to sort out, a consumer product like a cellular phone may have many small parts consisting of over a dozen different types and colors of plastics। In a case like this, the resources it would take to separate the plastics far exceed their value and the item is discarded. However, developments are taking place in the field of Active Disassembly, which may result in more consumer product components being re-used or recycled. Recycling certain types of plastics can be unprofitable, as well. For example, polystyrene is rarely recycled because it is usually not cost effective. These unrecyclable wastes can be disposed of in landfills, incinerated or used to produce electricity at waste-to-energy plants.
Common plastics and their uses
Polypropylene (PP)
Food containers, appliances, car fenders (bumpers).
Polystyrene (PS)
Packaging foam, food containers, disposable cups, plates, cutlery, CD and cassette boxes.
High impact polystyrene (HIPS)
fridge liners, food packaging, vending cups.
Acrylonitrile butadiene styrene (ABS)
Electronic equipment cases (e.g., computer monitors, printers, keyboards).
Polyethylene terephthalate (PET)
carbonated drinks bottles, jars, plastic film, microwavable packaging.
Polyester (PES)
Fibers, textiles.
Polyamides (PA) (Nylons)
Fibers, toothbrush bristles, fishing line, under-the-hood car engine mouldings.
Poly(vinyl chloride) (PVC)
Plumbing pipes and guttering, shower curtains, window frames, flooring.
Polyurethanes (PU)
cushioning foams, thermal insulation foams, surface coatings, printing rollers. (Currently 6th or 7th most commonly used plastic material, for instance the most commonly used plastic found in cars).
Polycarbonate (PC)
Compact discs, eyeglasses, riot shields, security windows, traffic lights, lenses.
Polyvinylidene chloride (PVDC) (Saran)
Food packaging.
Polyethylene (PE)
Wide range of inexpensive uses including supermarket bags, plastic bottles.
Bayblend (PC/ABS)
A blend of PC and ABS that creates a stronger plastic. :Car Interior and exterior parts
Food containers, appliances, car fenders (bumpers).
Polystyrene (PS)
Packaging foam, food containers, disposable cups, plates, cutlery, CD and cassette boxes.
High impact polystyrene (HIPS)
fridge liners, food packaging, vending cups.
Acrylonitrile butadiene styrene (ABS)
Electronic equipment cases (e.g., computer monitors, printers, keyboards).
Polyethylene terephthalate (PET)
carbonated drinks bottles, jars, plastic film, microwavable packaging.
Polyester (PES)
Fibers, textiles.
Polyamides (PA) (Nylons)
Fibers, toothbrush bristles, fishing line, under-the-hood car engine mouldings.
Poly(vinyl chloride) (PVC)
Plumbing pipes and guttering, shower curtains, window frames, flooring.
Polyurethanes (PU)
cushioning foams, thermal insulation foams, surface coatings, printing rollers. (Currently 6th or 7th most commonly used plastic material, for instance the most commonly used plastic found in cars).
Polycarbonate (PC)
Compact discs, eyeglasses, riot shields, security windows, traffic lights, lenses.
Polyvinylidene chloride (PVDC) (Saran)
Food packaging.
Polyethylene (PE)
Wide range of inexpensive uses including supermarket bags, plastic bottles.
Bayblend (PC/ABS)
A blend of PC and ABS that creates a stronger plastic. :Car Interior and exterior parts
The most-often recycled plastic, HDPE or number 2, is downcycled into plastic lumber, tables, roadside kerbs, benches, truck cargo liners, trash receptacles, stationery (e.g rulers) and other durable plastic products and is usually in demand. The white plastic "peanuts" used as packing material are often accepted by shipping stores for reuse.
In Israel successful trials have shown that plastic films recovered from mixed municipal waste streams can be recycled into useful products.
Similarly, agricultural plastics such as mulch film, drip tape and silage bags are being diverted from the waste stream and successfully recycled into bulk resin commodities in Labelle, FL. Historically, these agricultural plastics have primarily been either landfilled or burned on-site in the fields of individual farms.
The environmental benefits of recycling plastic are that it produces less sulphur dioxide, less waste and less carbon dioxide.
In Israel successful trials have shown that plastic films recovered from mixed municipal waste streams can be recycled into useful products.
Similarly, agricultural plastics such as mulch film, drip tape and silage bags are being diverted from the waste stream and successfully recycled into bulk resin commodities in Labelle, FL. Historically, these agricultural plastics have primarily been either landfilled or burned on-site in the fields of individual farms.
The environmental benefits of recycling plastic are that it produces less sulphur dioxide, less waste and less carbon dioxide.
