Low density polyethylene ( LDPE ) is a thermoplastic made of ethylene monomer. It was the first level of polyethylene, manufactured in 1933 by Imperial Chemical Industries (ICI) using a high pressure process through free radical polymerization. The making uses the same method today. The EPA estimates 5.7% of LDPE (recycle number 4) is recycled. Despite competition from more modern polymers, LDPE continues to be an important plastic class. In 2013, the worldwide LDPE market reaches a volume of approximately US $ 33 billion.
Video Low-density polyethylene
Properti
LDPE is defined by the density range 0.917-0.930 g/cm 3 . It is not reactive at room temperature, except by strong oxidizing agents, and some solvents cause swelling. Can withstand 80 ° C continuously and 95 ° C for a short time. Made in opaque or opaque variations, quite flexible and tough.
LDPE has more branching (about 2% of carbon atoms) than HDPE, so the intermolecular forces (triggered by dipole inductions instantly dipole) are weaker, their tensile strength is lower, and resistance is higher. Also, because the molecules are less dense and less crystalline because of the side branches, the density is lower.
Chemical resistance
- Excellent resistance (no attack/no chemical reaction) to dilute and concentrate acids, alcohols, bases and esters
- Good resistance (small attacks/very low chemical reactivity) to aldehydes, ketones and vegetable oils
- Limited endurance (moderate attacks/significant chemical reactions, suitable for short-term use only) to aliphatic and aromatic hydrocarbons, mineral oils and oxidizers
- Poor resistance, and is not recommended for use with halogenated hydrocarbons.
Maps Low-density polyethylene
Apps
LDPE is widely used for the manufacture of various containers, bottles, wash bottles, tubes, plastic bags for computer components, and various printed laboratory equipment. The most common use is in plastic bags. Other products made from it include:
- General purpose trays and containers
- Stainless work surface
- Parts that need to be welded and workable
- The parts that need flexibility, which works really well
- A very soft and flexible part like a snap-on cover
- Six pack ring
- The milk and milk cartons are made of liquid packaging boards, laminated paperboard and LDPE (as a waterproof inner and outer layer), and often with a layer of aluminum foil (thus becoming aseptic packaging).
- Packaging for computer hardware, such as hard disk drives, display cards, and optical disk drives
- Slide Playground
- Plastic lathe
See also
- Polyethylene low-density linear (LLDPE)
- High-density polyethylene (HDPE)
- Medium density medium (MDPE)
- Very high molecular weight polyethylene (UHMWPE)
- Polyethylene terephthalate (PET/PETE)
- Stretch wrap
References
External links
- 2010_MSW_Tables_and_Figures_508.pdf. epa.gov
Source of the article : Wikipedia
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