Plastic package
The term plastic (derived from gr. plastēs) covers a wide range of polymerization products that can be molded in a state of plasticity (mostly in 160-250 C temperature). Plastics may contain other substances besides polymers. Plastic can be classified in many ways, but most commonly by their polymer backbone (polyvinyl chloride, polyethylene, polymethyl methacrylate, and other acrylics, silicones, polyurethanes, etc.). Other classifications include thermoplastic, thermoset, elastomer, engineering plastic, addition or condensation or polyaddition (depending on polymerization method used), and glass transition temperature.
The first plastic –celluloid- was invented by John Wesley Hyatt in 1868 (USA).
Plastic is widely used because of its cheapness, good characteristics and plasticity. The product molding doesn’t depend on complexity of form and lasts only for 0, 2-5 minutes. Moreover the recycling process is easily automated, the product doesn’t need further processing. The appearance, characteristics and conversion characteristics enable to create products of various forms. It is economical to use plastics instead of metals in automobile, aviation and other industries. Spongy plastics insulate heat and sound. Some of the plastics are used for ammunition of organs, surgical threads and glues.
Plastic is commonly used for food, drinks storage and package, eg. bags, boxes, package film, plastic tableware, bottles, etc.
To assist recycling of disposable items, a now-familiar scheme was created to mark plastic bottles by plastic type. Using this scheme a recyclable plastic container is marked with a triangle of three "chasing arrows", which encloses a number giving the plastic type:
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Mark |
Name |
Found |
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PET (PETE), polyethylene terephthalate |
Commonly found on soft drink and water bottles, cooking oil bottles, washing liquids and detergent bottles. |
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HDPE, high-density polyethylene |
Commonly found on detergent bottles, milk jugs, water bottles, some plastic bags.
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PVC, polyvinyl chloride |
Commonly found on plastic pipes, outdoor furniture, shrink-wrap, water bottles, and liquid detergent containers. |
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LDPE, low-density polyethylene |
Commonly found on dry-cleaning bags, produce bags, trash can liners, food storage containers.
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PP, polypropylene |
Commonly found on bottle caps, drinking straws, yogurt containers.
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PS, polystyrene |
Commonly found on cups, plastic tableware, meat trays, take-away food clamshell containers.
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OTHER, other: This plastic category, as its name of "other" implies, is any plastic other than the named #1–#6 |
Commonly found on certain kinds of food containers, babies’ bottles, tableware, water bottles. New bioplastics can be marked #7. |
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