Monday, January 20, 2014

Basic Details Of Plastics

By Lenna Stockwell


Plastic nowadays is obviously an important substance for us. A mix of plastic or just plastic and other materials is what many different packages contain. We use these products and several of them are made of party or even entirely out of plastics. There are different kinds of plastics and each of those plastics has several functions and capabilities.

Organic solids mixed together are what a plastic is in general and it can be formed into a specific shape. These solid objects can be a blend of synthetic or even be entirely synthetic and naturally occurring or semi-synthetic polymers. The majority of plastics are created by the use of synthetic polymers which were extracted from petrochemicals.

Plastics are classified in several different ways and this includes the polymerization process by which the plastic is created, the processibility of the plastic and the general chemical nature of the plastic. When it comes to the processibility, plastic is divided into two categories - thermoplastic or thermoset plastic.

Both of these types of plastic have the word thermo which means that heat is applied to transform these plastics into products or packages. With a thermoplastic, the plastic item in question can be recycled, melted down and molded into a new product again and again. With thermoset plastics, this is not the case, and when these plastics are heated, they undergo a chemical change that means they cannot be melted down and reused. While these plastics technically cannot be melted down and reformed, some can be used again for other purposes. For instance, vulcanized rubber used for tires can be shredded and used to help produce asphalt.

Plastics are further classified by their physical properties beyond those two basic classifications which might include factors such as density, resistance to chemicals, glass transition, temperature and tensile strength. Tensile strength is the maximum amount of stress that the plastic can withstand when you are stretching it without breaking. Basically the temperature at which a substance moves from a hard state into a molten state is the glass transition temperature where it can be molded.

Density is the overall strength of an item although technically this means the mass per unit volume. Polypropylene is a good example which is used to make products like yogurt cups. A higher density item as an example would be Acrylonitrile butadiene styrene and it is used to create products like LEGO bricks, some auto parts and a few musical instruments.

Resistance to chemicals is one very important classification that is mentioned above this. A bottle of bleach that you keep by your washing machine is a great example of that. The container which is the bottle of the bleach liquid is a type of thermoplastic that is highly resistant to chemicals. The resistance of the plastic to the bleach liquid is pretty high otherwise the bleach would melt through the plastic and leak from it. Bleach is known to burn the skin and eyes even though it is a helpful detergent product and it is also poisonous to any living creature so it should be contained safely. The yogurt cup that you use does not need to be resistant to chemicals or many other food products.




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