HDPE – High Density Polyethylene
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. The mass density of high-density polyethylene can range from 0.93 to 0.97 g/cm3.
Although the density of HDPE is only marginally higher than that of low-density polyethylene, HDPE has little branching, giving it stronger intermolecular forces and tensile strength than LDPE.
The difference in strength exceeds the difference in density, giving HDPE a higher specific strength.
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).
In 1953, Karl Ziegler of the Kaiser Wilhelm Institute (renamed the Max Planck Institute) and Erhard Holzkamp invented high-density polyethylene (HDPE).
The process included the use of catalysts and low pressure, which is the basis for the formulation of many varieties of polyethylene compounds.
Two years later, in 1955, HDPE was produced as pipe. For his successful invention of HDPE, Ziegler was awarded the 1963 Nobel Prize for Chemistry.
Ineos and LyondellBasell are the leading technology licensors for HDPE.
LyondellBasell, SABIC, Chevron Phillips, Dow Chemical, Ineos, ExxonMobil, IPIC group, NPC Iran, SINOPEC group, Total PC, PetroChina Group, Braskem Group and Reliance Industries Ltd are some of leading producers of HDPE.
The global capacity of HDPE was 46.5 MMT in 2015 and demand was around 40 MMT. The capacity is expected to increase to 49 MMT in 2016 with demand reaching 41.5 MMT.
In India, PE major ONGC Petro additions Ltd (OPaL), is in the initial stages of starting up its two 360 KTA LLDPE/HDPE swing lines in February 2017, after achieving on-spec output at its standalone HDPE and PP units, which have a designed capacity of 340 KTA each.
Reliance Industries Ltd (RIL), which is also a polyolefins major, is also on track to start up its LDPE and LLDPE/HDPE swing lines by the end of the first quarter.
High-density polyethylene (HDPE) is principally used for the manufacture of high-performance pipe, blow-molded household and industrial bottles, oil bottles, injection-molded food containers, consumer durables and disposable goods and film goods such as grocery sacks and merchandise bags.
HDPE finds its application in Raffia, Blow Moulding, Film, Pipes and Injection Moulding. Consumption wise it is in order of HD-Film GP Blow Moulding, Raffia, Pipe, have the major share.
Large and Medium Blow Moulding containers, Pipe, General Purpose BM containers are currently the leading growth sectors.