Types of Plastic

I've got one word for you: plastics.  Plastics are everywhere.  If you're reading this, you're probably using plastics right now, either from the keys in your keyboard or the computer itself.  Plastics can be used as containers or as glass-substitutes or as keychains or for basic appliances.  Plastic is a broad term for a synthetic material that is malleable and easy to form into various shapes.  This, combined with their cheap cost, is largely the reason for the massive demands for plastic in the world today.  They are used for a HUGE amount of what you see and use every day.  There are two types of plastics you see in everyday life, and then seven categories of plastics that can and can't be recycled, and we will go through both of these sets.

The Two Types of Plastic

Plastics can be divided into two simple groups.  The difference is in their physical properties, chemical makeup, and mode of production.  The two types are Thermoplastics and Thermosetting Plastics, or Thermosets.

Thermoplastics - Thermoplastics are the type of plastic you see in plastic bags or in milk jugs.  They are flexible and malleable and can be melted and reformed into other shapes.  If they are cooled, they shatter easily, if they are heated, they will melt.  Think of plastic straws and the wrapper on your American cheese.  Rubber falls into this category of plastics.  Typically, these type of plastics are more flimsy and, since they require less processing, are easier to make.  As a result of this, they tend to be more environment-friendly.

Thermosets - Thermosets are any plastics that have been created to lose their malleability and stay set in their molded form permanently.  This is any sort of plastic that you could snap in half at regular temperature.  If you were to heat this to try and melt it, the material would burn before it would melt, unlike the thermoplastics.  Despite this, they burn at much higher temperatures than thermoplastics, so they are useful in that sense.  They are also much more durable and can handle a decent amount of wear and tear.  Some of these plastics are so strong that, when formed into nylon, can stop a bullet, hence, nylon bullet-proof vests.

Recycling Plastics:  The Seven Categories

Recycling plastics has become something of an issue lately because the materials aren't particularly biodegradeable, so it's much more useful to use them over again rather than make new ones.  Plastics are made up of complex molecular chains, which, for the sake of this article, we're going to avoid getting into.  Point being, something that complex doesn't break down easily so recycling plastics is important.  To find out which category these items fit into, you can usually look on the item itself and see a number within the little recycling triangle logo.  This number indicates what kind of plastic it is, and that in turn indicates how it can be used.

1. Polyethylene Terephthalate (PETE) - 2-liters, water bottles, various other thin-plastic bottles used for holding foods - This is the most easily recycled material, as it is the least complex polymer.

2. High-Density Polyethylene (HDPE) - Generally found on milk jugs or anything holding a thicker-substance material, such as laundry detergent or dishwashing soap.

3. Polyvinyl Chloride (PVC) - Famous for the PVC pipe.  Also found in household objects that don't really come into contact with food, like shower curtains or outdoor furniture.

4. Low-Density Polyethylene (LDPE) - Some Tupperware containers, plastic bags at grocery stores.

5. Propropylene (PP) - Bottlecaps or straws, some medicine bottles.

6. Polystyrene (PS) - Packaging peanuts and pretty much any other form of styrofoam.

7. Other - This is anything that doesn't fit into the other plastics.  Some kinds of food storage plastic containers fall under 7.

Any recycling company will take type 1.  If they don't, you probably have good reason to suspect they're just a front for the mafia.  Most companies will take type 2, but they may have restrictions about exactly what types of plastic containers they'll take.  Type 3 is not a recyclable type of plastic because PVC can be toxic.  Do not burn PVC!  You want to find another use for it.  Type 4 might be accepted by your recycling program, but in general, they aren't.  Find out before you start putting it out on the curb. Type 5 is the same as type 4, you can put it out for some recycling programs, but you'll want to check first.  Type 6 is not a good type.  Ideally, you should avoid using styrofoam when possible, as it takes forever to break down and isn't very recyclable, but sometimes it might not be your choice.  If, for example, you've gotten packaging peanuts, some places will take them to reuse for future packaging.  Also, some modern packaging peanuts are made of biodegradable corn-oil, and if you stick them into the sink and run water over them, they'll dissolve.  If it's available, send things with these type of peanuts rather than the styrofoam.  Some recycling programs will, however, accept type 6.  Type 7 is generally not recycled, but, like 4, 5, and 6, more and more companies are starting to accept them.  It's possible this type of plastic is on the way out anyway because of their potential health hazard to children.

From an environmental standpoint, really, plastics are never the ideal choice.  Though they are incredibly useful and versatile from a product standpoint, they aren't really organic at all, so their use isn't ever good for the environment.  If you can, limit your use of disposable plastics.  For example, carry around a Nalgene or hard plastic water bottle rather than buying tons of bottled water.  If you can, when you're at the restaurant, either get your drink on tap or in a glass bottle.  Glass is a more natural material and easier to recycle.  For other plastics, like in computers or bullet-proof vests, you might be best served to NOT go organic and just buy what's out there.  It's not like you're going through these every week, so their environmental impact is minimal.