High density polyethylene (HDPE)
High-Density Polyethylene (HDPE), chemically, has a very high molecular weight. Polyethylene itself is a whitish, semi-crystalline, and effectively opaque engineering thermoplastic, it normally comes in black or white but can have a range of colours. It comes under category 2 in the Resin Identification Code (RIC) system and can sometimes be confused with High density polypropylene (HDPP) which comes under catoegory 5 because of its similiar use in the manufacture of pipes.
In households HDPE is commonly found in containers for motor oil, shampoos, soap bottles, detergents, and bleaches, in construction it is used for vapour barriers, air and moisture barrier membranes, carpet textiles, roofing, industrial adhesives and tapes. It may also be found is temporary use as packaging elements such as window films, counter top protection, trims and skirts etc. It is most commonly associated with piping and has been used for municipal and industrial water applications for more than 50 years, as well as more recently for ground source geothermal applications.
HDPE sits within a family of different densities of polyethylene in the use of different pipework and although some HDPE pipes are actually manufactured from High Density Polypropylene (HDPP) they may still be referred to as HDPE pipes. Other products with in the same family include Low Density Polyethylene (LDPE), Linear Low-Density Polyethylene (LLDPE), Medium Density Polyethylene (MDPE), Cross-linked polyethylene (XLPE ), Ultra-high molecular weight polyethylene (UHMW). Medium Density Polyethylene (MDPE) is also often used in the manufacture of piping systems.
Other HDPE pipes are PE100 a Polyethylene version with a Minimum Required Strength (MRS) of 100 at 50 years and 20ยบ according to ISO4427, theses are for high demands pipe applications. PE80 pipes, are for natural gas distribution networks with pressure rates of up to 4 bars, drinking water pipe with pressure rate up to 16 bar - sewers, outfall pipes, industrial pipes. Other MDPE pipes might be PE 63 which are drinking water medium pressure piping systems and irrigation system
All of these forms of PE. HD, MD.LD etc can be recycled however in reality the amount of recycling is relatively low, and new pipework generally has as little as 5% recycled content.
[edit] Related articles on Designing Buildings
- Glass reinforced plastic GRP
- Glass fibre reinforced plastic
- Low Density Polyethylene (LDPE)
- Polycarbonate plastic
- Polypropylene in the construction industry.
- Plastic cladding
- Plastic coating market
- Plastic in construction
- Plastic in concrete
- Recycled plastic bridges
- Wood plastic composites market for construction
Featured articles and news
Specifying rendered external wall insulation for fire safety
How to interrogate the evidence provided to the specifier.
The benefits of writing articles for your organisation
How to create a profile for your organisation and publish for free.
No Falls Week. The importance of safe working at height
What to expect and what is on offer to avoid accidents.
Scottish Government action to reach net-zero targets
Retrofit expert group highlight critical actions needed.
A forward thinking, inclusive global community of members.
From engineered product life-spans, to their extension.
Circular economy in the built environment
A brief description from 2021. Where are we now?
Mental Health Awareness Week with ABS
Architects Benevolent Society programme of activity.
CLC publishes domestic retrofit competency framework
Roadmap of Skills for net zero.
May 13-19: Moving more for our mental health.
Understanding is key to conservation.
Open industry engagement survey seeks responses
Institutions and the importance of engagement.
National Retrofit Hub unveils new guide
Digital Building Logbooks and Retrofit: An Introduction.
Enhancing construction site reporting efficiency
Through digitisation and the digital revolution.