This MedLibrary.org supplementary page on High-density polyethylene is provided directly from the open source Wikipedia as a service to our readers. Please see the note below on authorship of this content, as well as the Wikipedia usage guidelines. To search for other content from our encyclopedia supplement, please use the form below:
Related Sponsors
 |
This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. (January 2008) |
High-Density PolyEthylene(HDPE) or PolyEthylene High-Density (PEHD) is a polyethylene thermoplastic made from petroleum. It takes 1.75 kilograms of petroleum (in terms of energy and raw materials) to make one kilogram of HDPE. HDPE is commonly recycled, and has the number "2" as its recycling symbol.
Contents |
Properties
HDPE has little branching, giving it stronger intermolecular forces and tensile strength than lower-density polyethylene. It is also harder and more opaque and can withstand somewhat higher temperatures (120 °C/ 248 °F for short periods, 110 °C /230 °F continuously). High-density polyethylene, unlike polypropylene, cannot withstand normally-required autoclaving conditions. The lack of branching is ensured by an appropriate choice of catalyst (e.g., Ziegler-Natta catalysts) and reaction conditions. HDPE contains the chemical elements carbon and hydrogen.
Applications
HDPE is resistant to many different solvents and has a wide variety of applications, including:
- Containers
- Laundry detergent bottles
- Milk jugs
- Fuel tanks for vehicles
- Folding tables
- Folding chairs
- Storage sheds
- Portable basketball system bases
- Plastic bags
- Containment of certain chemicals
- Chemical-resistant piping systems
- Heat-resistant fireworks display mortars
- Geothermal heat transfer piping systems
- Natural gas distribution pipe systems
- Water pipes, for domestic water supply
- Coax cable inner insulators (dielectric insulating spacer)
- Root barrier
- Corrosion protection for steel pipelines
- Tyvek
- Snowboard rails and boxes
- Bottles, suitable for use as refillable bottles
- Modern hula hoops
- Ballistic plates
- Fences1
HDPE is also used for cell liners in subtitle D sanitary landfills, wherein large sheets of HDPE are either extrusion or wedge welded to form a homogeneous chemical-resistant barrier, with the intention of preventing the pollution of soil and groundwater by the liquid constituents of solid waste.
One of the largest uses for HDPE is wood plastic composites and composite wood, with recycled polymers leading the way.
HDPE is also widely used in the pyrotechnics trade. HDPE mortars are preferred to steel or PVC tubes because they are more durable and more importantly they are much safer compared to steel or PVC. If a shell or salute were to malfunction (flowerpot) in the mortar, HDPE tends to rip and tear instead of shattering into sharp pieces which can kill or maim onlookers. PVC and steel are particularly prone to this and their use is avoided where possible.
See also
- Linear low-density polyethylene
- Low-density polyethylene
- Phillips Disaster
- Resin identification code
- Ultra-high-molecular-weight polyethylene
- Plastic recycling
References
External links
 |
This inorganic compound-related article is a stub. You can help Wikipedia by expanding it. |
Wikipedia content modification information:
- This page was last modified on 29 November 2008, at 20:41.
Wikipedia Authorship and Review
Wikipedia content provided here is not reviewed directly by MedLibrary.org. Wikipedia content is authored by an open community of volunteers and is not produced by or in any way affiliated with MedLibrary.org.
Wikipedia Usage Guidelines
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on "High-density polyethylene".
The URL for this specific entry is:
All Wikipedia text is available under the terms of the GNU Free Documentation License. (See Copyrights for details). Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.