Material Information
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Polyester
Polyester is a category of polymers which contain the ester functional group in their main chain. Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate (PET). Polyester fabrics may exhibit other advantages over natural fabrics, such as improved wrinkle resistance. Polyester dries fast since it’s not particularly absorbent to begin with. It doesn’t require hot water in the wash, because it doesn’t get all that dirty.
Polyester has a high strength-to-weight ratio, and is the most widely sold manufactured fiber. It is utilized in all types of clothing, home furnishings (bedspreads, sheets, pillows, curtains, furniture, and carpets), and as a reinforcing fiber in tires, belts, and hoses. It is also the most heavily recycled polymer in the world. New insulating polyester fiberfill products - put to the test by climbers on Mount Everest - are used in climbing suits, sleeping bags, parkas, and other high-performance outdoor wear. Polyester fleece lines dry suits to permit winter windsurfing.
This material is widely used in the apparel industry and makes a fantastic material for reusable shopping bags.
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Nylon
Nylon is a thermoplastic silky material, first used commercially in a nylon-bristled toothbrush (1938), followed more famously by women's stockings ("nylons"; 1940). It is made of repeating units linked by peptide bonds (another name for amide bonds) and is frequently referred to as polyamide (PA). Nylon was the first commercially successful synthetic polymer.
This material is widely used in the apparel industry and makes a fantastic material for reusable shopping bags.
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Cotton
Cotton is a soft, staple fiber that grows in a form known as a boll around the seeds of the cotton plant, a shrub native to tropical and subtropical regions around the world, including the Americas, India and Africa. The fiber most often is spun into yarn or thread and used to make a soft, breathable textile, which is the most widely used natural-fiber cloth in clothing today.
From an engineering standpoint, cotton is a beauty, its soft cellulose fibers densely interlocked for strength.
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Polypropylene
Polyolefins such as Polyethylene (PE) and Polypropylene (PP) are simpler polymer structures that do not need plasticizers, although they do use additives such as UV and heat stabilizers, antioxidants and in some applications flame retardants. The polyolefins pose fewer risks and have the highest potential for mechanical recycling. Both PE and PP are versatile and cheap, and can be designed to replace almost all PVC applications. PE can be made either hard, or very flexible, without the use of plasticizers. PP is easy to mold and can also be used in a wide range of applications.
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The problems with PVC bags according to GreenPeace
Globally, over 50% of PVC manufactured is used in construction, in products such as pipelines, wiring, siding, flooring and wallpaper. As a building material PVC is cheap, easy to install and easy to replace. PVC is replacing ‘traditional’ building materials such as wood, concrete and clay in many areas. Although it appears to be the ideal building material, PVC has high environmental and human health costs that its manufacturers fail to tell consumers.
From its manufacture to its disposal, PVC emits toxic compounds. During the manufacture of the building block ingredients of PVC (such as vinyl chloride monomer) dioxin and other persistent pollutants are emitted into the air, water and land, which present both acute and chronic health hazards. During use, PVC products can leach toxic additives, for example flooring can release softeners called phthalates. When PVC reaches the end of its useful life, it can be either landfilled, where it leaches toxic additives or incinerated, again emitting dioxin and heavy metals. When PVC burns in accidental fires, hydrogen chloride gas and dioxin are formed.
The pyramid of plastics is a ranking of plastics according to their hazardous characteristics. PVC, the most problematic plastic, is at the top of the pyramid, and biobased plastics, the least polluting of the plastics, are at the pyramid's base. It represents an ongoing process to qualify the main plastics in the economy. More plastics can be added as necessary and qualifications may change depending new information on the material, such as in production processes or the use of toxic additives.
1) Polyvinyl chloride (PVC) and other halogenated plastics
2) Polyurethane (PU), Polystyrene (PS), Acrylonitrile-butadiene-styrene (ABS), Polycarbonate (PC)
4) Biobased plastics
In comparison with PVC, PE and PP use fewer problematic additives, have reduced leaching potential in landfills, reduced potential for dioxin formation during burning (provided that brominated/chlorinated flame retardants are not used), and reduced technical problems and costs during recycling.
Source : http://archive.greenpeace.org/toxics/pvcdatabase/bad.html
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