What is HDPE ?
HDPE is high density kind of PE(polyethylene plastics). Compared to other polyethylene, stronger and more rigid and comparatively heavier and thought then LDPE (low density polyethylene). HDPE is lighter then water. It can be manufactured by means of using molding technologies or extrusion processes. Easily machined and can be constructed using special welding processes. It is hard to combine PE pieces using glue or some chemicals. Naturally looks like wax, lusterless and opaque. By means of UV additive, resistance to sun light and atmospheric conditions can be strengthen but in that case color turns black. Suitable for food industry applications.
Low density polyethylene (PE32) was developed at 1950s and used for water networks. Then higher density and stronger polyethylene of PE63 developed for gas networks and used for 4 bar internal pressure systems. Many designer and manufacturer companies noticed the flexibility of that material and invested on that subject a short time and at the beginning of 1990s, developed PE80 and PE100 of high density polyethylene. Very first applications with HDPE pipes were performed in USA and CANADA at 1960s and these first applications of PE are still working today without any problem.
Polyethylene pipes are classified according to MRS (minimum required strength) of the raw material. MRS is the strength of material to the applied internal pressure at 20C temperature for 50 years long. And PE is classified as following according to that evaluation.
PE32-3.2MRS PE40-4.0MRS PE63-6.3MRS PE80-8.0MRS PE100-10.0MRS
Main advantages and properties of polyethylene:
- Resistant to ageing. Life of PE is assumed to be 50 years but real life is longer then that. Resistance to crack growth is perfect.
- Since PE materials are very elastic, it can perform a good applicability for any kind of bad conditions.
- Compared to steel, wooden and aluminum, PE is lighter and easily constructed. Than material gives various constructive alternatives to the manufacturer.
- Polyethylene can resist against every kind of environmental working conditions with its anti-corrosive property.
- Impact strength is extremely high and it is not brittle at low temperatures.
- Easy to clean and doesn’t keep dust on it. Does not include toxic material.
- High resistance to freezing. Freezing the liquid in which PE floating, cannot effect its material properties.
- Other than all these specialties, in material basis, PE is economical compared to steel, aluminum and wooden.
- Non Magnetic.