difference between polyethylene & polypropylene
Polypropylene is stronger that polyethylene. High resistance to environment. Have higher melting point. The chemical reason is that polypropylene have triple bond carbon. However, polyethylene have only double carbon bonded to each other. 8 people found this useful.
Polyethylene has more demand however than polypropylene. Polypropylene is used extensively in the automotive industry as well as the packaging industry. 70% of the polypropylene uses is for packaging needs for the food industry. It can be made into bottles, food containers, food crates and pallets.
Polypropylene, also know as polypropene is a form of plastic just as polyethylene is. What separates polypropylene from polyethylene for starters is the fact that polypropylene can be molded in essence becoming pliable above a certain temperature. When it cools it will return to its solid state.
The translucent nature of polyethylene prohibits a the greater amount of light than the transparent polypropylene. Light can be particularly harmful to collectibles, especially magazines, comics, books, photographs, artwork or any kind of cover or jacket that has color and/or photos or illustrations.
Many of the polypropylene sleeves are less than 2 mil. Many of the sleeves being sold on the internet and by hobby and comic shops are very flimsy and range from .5 mil to 2 mil. The majority of commercially-available polypropylene sleeves are 1 to 1.5 mil. Our polyethylene sleeves are 2 mil and 3 mil, respectively. In more chemistry-speak, propylene (CH3CH:CH2) is is a sub-stratum of ethylene. Ethylene is the purest form of the base chemical and thus the purer better of the two.