LDPE Characteristics

Low-density polyethyline, or LPDE, is a type of film constructed for structural strength and resistance to impact and chemical breakdown. Like all film, it is physically described as a piece of plastic much longer and wider than it is thick. It is commonly used in applications where corrosion resistance is needed but high temperatures and the film's stiffness are not concerns.

Physical Appearance

• LDPE film can be many colors, densities and thicknesses. Its primary distinguishing characteristic is its ability to retain integrity while being stretched or otherwise deformed. This property of LDPE film is most observable in plastic bags constructed from it, such as trash bags, which can withstand a great deal of strain before their structure is compromised.

Moleculare Chains in LDPE

• LDPE is, on the molecular level, constructed of chains of monomer ethylene, which can vary in length and in how much branching they do. The length of the these chains will determine the density of the plastic film as well as its specific properties.

Chain Branching

• Because LDPE has more chain branching than other plastic films, the molecules are less able to interact. This reduces the overall rigidity of all LPDE films compared to other non-LDPE plastic films. This property also makes it more resilient and resistant to tear or puncture, making it an ideal plastic for use in a wide variety of applications that require some stretching, such as garbage bags, ice trays and cable sheathes.

Recycling and Breaking Down

• The molecular structure of LDPE allows it to be completely recycled for a variety of uses, from plastic components in toys, bottle caps and typewriter ribbons to soft filling in pillows and clothing. If not recycled, LDPE is considered nonbiodegradable, as it will take several centuries to degrade. Recent studies in the application of bacteria to discarded LDPE have yielded some success in breaking it down much faster, and research is being done in this area.