low density polyethylene

Low-density polyethylene (LDPE) is a thermoplastic made from the monomer ethylene. It was the first grade of polyethylene, produced in 1933 by Imperial Chemical Industries (ICI) using a high pressure process via free radical polymerization. Its manufacture employs the same method today.

1. What is low density polyethylene used for?
2. What is the difference between PE and LDPE?
3. What are the characteristics of low density polyethylene?
4. Is LDPE waterproof?
5. Is low-density polyethylene safe?
6. Where is polyethylene found?
7. Which is better LDPE or HDPE?
8. How safe is polyethylene?
9. How can you tell polyethylene?
10. Is low density polythene hard?
11. What is low density?
12. How is low density polyethylene made?

What is low density polyethylene used for?

Low density polyethylene (LDPE) is used mainly in film applications for both packaging and non-packaging applications. Other markets include extrusion coatings, sheathing in cables and injection moulding applications.

What is the difference between PE and LDPE?

Produced through free-radical polymerization, LDPE has the most long- and short-chain branching of any form of PE, resulting in its lower density. The branching keeps the molecular chains from packing tightly in its crystaline form, so LDPE has less tensile strength but greater ductility.

What are the characteristics of low density polyethylene?

Low density polyethylene has good chemical resistance and electrical properties, but it has a high thermal expansion and tends to fail under mechanical and thermal stress. Glass reinforcement improves its thermal expansion, strength, rigidity and temperature resistance.

Is LDPE waterproof?

LDPE is resistant to impact (doesn't break easily), moisture (water proof), and chemicals (can stand up to many hazardous materials).

Is low-density polyethylene safe?

Low-density polyethylene (LDPE) is used to make grocery bags, some food wraps, squeezable bottles, and bread bags. This plastic is considered to be relatively safe. The problem with LDPE is mainly an environmental one: It is not recyclable via curbside and other recycling programs.

Where is polyethylene found?

Polyethylene is produced from ethylene, and although ethylene can be produced from renewable resources, it is mainly obtained from petroleum or natural gas.

Which is better LDPE or HDPE?

LDPE is softer and more flexible than HDPE. It also has a lower melting point (115° C) and is more transparent. Compared to HDPE, it is more likely to crack under stress. HDPE is rigid and durable and offers greater chemical resistance.

How safe is polyethylene?

HDPE: high-density polyethylene

HDPE is commonly used in milk and juice bottles, detergent bottles, shampoo bottles, grocery bags, and cereal box liners. Like PET, it is also considered “safe," but has been shown to leach estrogenic chemicals dangerous to fetuses and juveniles.

How can you tell polyethylene?

One of the simplest ways to carry out a flame test is by cutting a sample from the plastic and igniting it in a fume cupboard. The colour of flame, scent and characteristics of burning can give an indication of the type of plastic: Polyethylene (PE) - Drips, smells like candlewax.

Is low density polythene hard?

Made in translucent or opaque variations, it is quite flexible and tough. LDPE has more branching (on about 2% of the carbon atoms) than HDPE, so its intermolecular forces (instantaneous-dipole induced-dipole attraction) are weaker, its tensile strength is lower, and its resilience is higher.

What is low density?

Low density, in real estate terms, describes the number of housing units per given unit of land in a particular area. Low density housing typically refers to residential areas occupied primarily by single-family homes or buildings with a small number of units.

How is low density polyethylene made?

Low-density polyethylene is manufactured by the process of the polymerization of ethylene at very high temperatures in a tubular reactor. In this tubular reactor, high-pressure polymerization allows further copolymerization of ethylene with polar co-monomers. The tubular process has an advantage over autoclave process.