Hi Dana,
The advantages and disadvantages of using plastic fenders are as follows: Plastic fenders are low in strength with a relatively high resistance to abrasion. Plastic fenders are resistant to chemical and biological attacks. Plastic fenders have moderate energy absorption capacity. The berthing reactions are also comparatively moderate and depends on the point of contact. Also since they are made from recycled material they are environmental friendly. The advantages and disadvantages of using timber fenders are: timber fenders are low in strength and are very susceptible to marine borer attacks and rotting. The energy absorption capacity is very low. Also generally the contact pressure between the vessels and the fender are high.
Regards,
hi dana
Advantages
Plastic is very useful in the building and construction, electronics (laptops wouldn't work well if they were made from glass), packaging (gladwrap), transportation industries. Very easy to make - water bottles, plastic bags, pens, cups etc etc
The main advantages of plastic materials are also the reason why plastic is such a problem. It lasts forever and it is very cheap to make. When I say it lasts forever, I mean it does not biodegrade. There is a flotilla of plastic the size of Texas in the Pacific Ocean. It gradually photo-degrades into tiny pieces that enter the marine food chain.
Plastic is good, light, strong and cheap to produce. There are many advantages to using plastic. It does not decompose but it can instead be recycled. This is done more easily than producing more plastic. Unlike aluminum cans, plastic bottles can be re-used and stored over and over again. Plastic is usually not breakable and it is see-through. It's light-weight and odourless. Plastic comes from a natural resource (oil) but CAN'T be re-made into bottles (but they can be re-made into other items- WEIRD!) It takes a long time to break down...
Advantages
The advantages of plastics are: Light weight, chemically resistant, can easily be shaped, durable, easy to colour in the mass, thermically insulating, acoustically insulating, electrically insulating, energy saving.
Advantages of pmma1.Good response to temperature changes,2. excellent resistance to many chemicals, .An excellent insulator, the surface resistivity of pmma is higher than that of most plastics,4.Despite the hard conditions of heat, cold, sunlight, and humidity, pmma maintain their original appearance and color.5. shatter-resistant,earthquake safe, and burglar-resistant.6.At the same strength and durability, it is only half the weight of glass.
DISADVANTAGES
It is a compound that is indestructible, even when it is melted the compound gas that is gives off is very harmful to our heath and environment; it weakens the ozone layer. Most plastic is produced from oil. The world is gradually running out of oil. Scientists are now developing plastics that are made from vegetable oil and other organic matter. This means that the plastic is more likely to be degradable, so it will be less of a problem in future.
