High-Density Polyethylene, usually shortened to PEX-AL-PEX pipe, can be a plastic polymer with flexible properties that make it well suited for a variety of applications.
High-density polyethylene, as the name suggests, has a higher specific density than low-density polyethylene, though this difference is only marginal. What really definitely makes the difference inside the physical properties of HDPE is lacking branching, meaning it is actually light by using a high tensile strength. Since there is no branching the structure is much 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 numerous advantageous properties which render it important in the manufacturing of various products. HDPE carries a comparatively high density in comparison with other polymers, by using a specific gravity of .95. HDPE is relatively hard and resistant against impact and can be subjected to temperatures up to 120oC without having to be affected.
These durable properties ensure it is excellent for heavy duty containers and HDPE is primarily utilized for milk containers, in addition to Tupperware, shampoo bottles, bleach bottles and motor oil bottles. Also, HDPE does not absorb liquid readily, rendering it good barrier material for liquid containers. Almost 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 numerous chemicals, hence it widespread use in healthcare and laboratory environments. It is actually proof against many acids, alcohols, aldehydes, esters, bases and oils.
HDPE is accepted at the most recycling centres worldwide, mainly because it is amongst the easiest plastic polymers to recycle. Most recycling companies will collect HDPE products and take those to large facilities to be processed.
First, the plastic is sorted and cleaned, to get rid of any unwanted debris. The plastic then must homogenised, to ensure only HDPE will be processed. If there are more plastic polymers in the batch, this could ruin the recycled end-product.
HDPE includes a specific density of .93 to .97 g/cm3. This is much lower than that of PET which happens to be 1.43-1.45 g/cm3, meaning that these plastic polymers could be separated by utilizing sink-float separation. However, HDPE pipe fittings has a similar specific density to PP, which implies the sink-float separation can not be used. In such a case, Near Infrared Radiation (NIR) techniques can be used, unless the plastic is way too dark and absorbs the infrared waves.
HDPE will be shredded and melted down to further refine the polymer. The plastic will then be cooled into pellets which may be employed in manufacturing.
Recycling plants can also take advantage of using a baler, which may compress the post-consumer waste to minimise energy utilized in transport.
Small steps at home can also be taken to recycle HDPE. With regards to milk bottles, these may be easily reused if washed out thoroughly first. To lessen packaging waste, buying plastic containers in large quantities is an additional great option.
Equally, carrier bags may also be reused when going shopping. Many large supermarkets also provide collection points for used carrier bags being recycled. Some plastic films have a message to recycle these with carrier bags on the supermarket instead of to go out of ‘kerbside’.
Recycling of HDPE is aided from the resin code about the product, that is an indiscriminate number assigned to different plastic polymers to assist separate plastics on the recycling stage. The resin identification code for top-density polyethylene is ‘2’.
The Environmental Great things about Recycling HDPE
The worldwide marketplace for HDPE is large, having a market volume of around 30million tons each year.
The volume of plastic used in plastic bags has reduced by around 70% during the last 2 decades because of the introduction of reusable canvas bags and using biodegradable materials, but dexqpkyy02 majority of bags are still created from PEX-AL-PEX pipe. Furthermore, you will find a growing industry for HDPE containers in China and India on account of increased standards of living, and also a higher need for HDPE pipes and cables on account of rapidly growing industries.
HDPE is non-biodegradable and may take centuries to decompose, it is therefore imperative that these bags and containers are recycled and used again.
Recycling HDPE has numerous benefits. For instance, it really is more cost effective to make a product from recycled HDPE than it is to produce ‘virgin’ plastic.
HDPE, like many plastic polymers, is produced using considerable quantities of standard fuels and it requires a total of 1.75kg of oil to manufacture just 1kg of HDPE.