High-density polyethylene
1911597
224894442
2008-07-10T21:52:01Z
69.181.22.105
/* Applications */
{{Unreferenced|date=January 2008}}
<!-- [[Image:Resin-identification-code-2-HDPE.svg|right|64px|HDPE has the resin identification code 2]] -->
[[Image:Resin-identification-code-2-HDPE.svg|120px|right|thumb| HDPE has [[Society of the Plastics Industry|SPI]] [[resin identification code|resin ID code]] 2]]
'''High-density polyethylene''' ('''HDPE''') is a [[polyethylene]] [[thermoplastic]] made from [[petroleum]]. It takes 1.75 [[kilogram]]s of petroleum (in terms of [[energy]] and raw materials) to make one kilogram of HDPE.
==Properties==
HDPE has little [[branching (chemistry)|branching]], giving it stronger [[intermolecular force]]s and [[tensile strength]] than lower-density [[polyethylene]]. It is also harder and more opaque and can withstand somewhat higher [[temperature]]s (120 °C/ 248 °F for short periods, 110 °C /230 °F continuously). High-density polyethylene, unlike [[polypropylene]], cannot withstand normally-required [[autoclave|autoclaving]] conditions. The lack of branching is ensured by an appropriate choice of [[catalyst]] (''e.g.'', [[Ziegler-Natta catalyst]]s) and [[chemical reaction|reaction]] conditions.
==Applications==
HDPE is resistant to many different [[solvent]]s and has a wide variety of applications, including:
* [[Container]]s
** [[Tupperware Corporation|Tupperware]]
** [[Laundry detergent]] bottles
** [[Milk]] jugs
** [[Fuel tank]]s for vehicles
* folding [[table]]s
* [[folding chair]]s
* storage [[shed]]s
* Portable basketball system bases
* [[Plastic bag]]s
* Containment of certain [[chemical compound|chemicals]]
* Chemical-resistant [[piping]] systems
* Heat-resistant [[fireworks]] display [[Mortar (weapon)|mortars]]
* [[Geothermal heating|Geothermal]] [[heat transfer piping]] systems
* [[Natural gas]] distribution pipe systems
* [[Water pipe]]s, for domestic water supply.
* [[Coax cable]] inner [[Electrical insulation|insulator]]s ([[dielectric]] insulating spacer)
* Root Barrier
* [[Corrosion]] Protection for [[Steel]] Pipelines.
* [[Tyvek]]
* [[Snowboard]] rails/ boxes.
* [[Bottles]], suitable for use as refillable bottles.
* enabled manufacture of the modern [[hula hoop]]
* ballistic plates
HDPE is also used for [[cell liner (sanitation)|cell liner]]s in [[subtitle D]] [[sanitary landfill]]s, wherein large sheets of HDPE are either [[extrusion]] or [[wedge welding|wedge welded]] to form a [[wiktionary:Homogeneous|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 composite]]s and composite wood, with [[Plastic recycling|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. It is a common myth that PVC doesn't show up on a [[X-ray]], PVC piping is not pure polyvinyl chloride, many other compounds are added to give the pipe its required characteristics and these enable PVC (in the form of piping) to be seen.
== See also ==
* [[Linear low-density polyethylene]]
* [[Low-density polyethylene]]
* [[Phillips Disaster]]
* [[Resin identification code]]
* [[Ultra-high-molecular-weight polyethylene]]
* [[Plastic recycling]]
== External links ==
* [http://www.societyofrobots.com/materials_hdpe.shtml HDPE for Robotics]
* [http://www.ides.com/pm/1_hdpe.asp HDPE Advantages & Disadvantages]
{{inorganic-compound-stub}}
[[Category:Polyolefins]]
[[Category:Plastics]]
[[Category:Recyclable materials]]
[[de:Polyethylen]]
[[ja:高密度ポリエチレン]]
[[th:High-density polyethylene]]