High-Density Polyethylene, usually shortened to PEX-AL-PEX pipe, is actually a plastic polymer with flexible properties which make it suitable for a variety of applications.
High-density polyethylene, as being the name suggests, has a higher specific density than low-density polyethylene, though this difference is simply marginal. What really helps to make the difference within the physical properties of HDPE is the absence of branching, meaning it is light with a high tensile strength. Since there is no branching the structure is far more closely packed, make HDPE a linear polymer. The branching could be controlled and reduced through the use of specific catalysts during production.
HDPE has several advantageous properties which make it crucial in the manufacturing of several products. HDPE has a comparatively high density in comparison to other polymers, having a specific gravity of .95. HDPE is pretty hard and proof against impact and might be put through temperatures of up to 120oC without getting affected.
These durable properties make it great for high quality containers and HDPE is primarily employed for milk containers, as well as Tupperware, shampoo bottles, bleach bottles and motor oil bottles. Also, HDPE is not going to absorb liquid readily, so that it is good barrier material for liquid containers. Almost still another (about eight million tons) of HDPE produced worldwide is commonly used for these types of containers.
Furthermore HDPE is an extremely resistant material to many people chemicals, hence it widespread use in healthcare and laboratory environments. It is actually resistant to many acids, alcohols, aldehydes, esters, bases and oils.
HDPE is accepted at most recycling centres in the world, as it is probably the easiest plastic polymers to recycle. Most recycling companies will collect HDPE products and take these to large facilities being processed.
First, the plastic is sorted and cleaned, to get rid of any unwanted debris. The plastic then has to homogenised, in order that only HDPE will probably be processed. If there are many plastic polymers within the batch, this will ruin the recycled end-product.
HDPE has a specific density of .93 to .97 g/cm3. This can be far lower than that of PET that is 1.43-1.45 g/cm3, which means these plastic polymers may be separated by making use of sink-float separation. However, HDPE pipe fittings features a similar specific density to PP, meaning the sink-float separation should not be used. In this instance, Near Infrared Radiation (NIR) techniques may be used, unless the plastic is simply too dark and absorbs the infrared waves.
HDPE is then shredded and melted as a result of further refine the polymer. The plastic will then be cooled into pellets which may be found in manufacturing.
Recycling plants may also take advantage of the use of a baler, that may compress the post-consumer waste to minimise energy utilized in transport.
Small steps in the home may also be taken up recycle HDPE. In terms of milk bottles, these could be reused if washed out thoroughly first. To lessen packaging waste, buying plastic bottles in bulk is another good option.
Equally, carrier bags can also be reused when going shopping. Many large supermarkets also provide collection points for used carrier bags to get recycled. Some plastic films consist of a message to recycle these with carrier bags at the supermarket and not to leave ‘kerbside’.
Recycling of HDPE is aided through the resin code around the product, which can be an indiscriminate number assigned to different plastic polymers to aid separate plastics in the recycling stage. The resin identification code for high-density polyethylene is ‘2’.
The Environmental Great things about Recycling HDPE
The worldwide niche for HDPE is large, having a market volume of around 30million tons annually.
The level of plastic employed in plastic bags has reduced by around 70% in the last twenty years due to the introduction of reusable canvas bags and using biodegradable materials, but dexqpkyy02 majority of bags will still be produced from PEX-AL-PEX pipe. Furthermore, there exists a growing market for HDPE containers in China and India because of increased standards of just living, and also a higher demand for HDPE pipes and cables on account of rapidly growing industries.
HDPE is non-biodegradable and will take centuries to decompose, therefore it is imperative these bags and containers are recycled and used again.
Recycling HDPE has many benefits. For example, it is actually more affordable to generate a product from recycled HDPE than it is to manufacture ‘virgin’ plastic.
HDPE, like many plastic polymers, is produced using considerable quantities of energy sources and yes it needs a total of 1.75kg of oil to produce just 1kg of HDPE.