High-density polyethylene recycling

PH)PE [OLEFIN POLYTffiRS - POLYETHYLENE - HIGH DENSITY POLYETHYLENE] (Vol 17) -as paper contamnants [RECYCLING - PAPER] (Vol 21)... 

Nor is it tme that poly(ethylene terephthalate) (PET) and high density polyethylene (HDPE) packaging are hsted as 1 and 2 in the Society of the Plastics Industry (SPI) recycling coding system because they are the most recyclable. The numbers assigned to each plastic in the SPI coding system are purely arbitrary and do not redect the material s recyclabihty. 

HDPE High-density polyethylene PCR Post-consumer recyclate... 

A vast number of polymer compounds are available commercially. Generally they are known by their polymer type in full or abbreviated (e.g., acrylic, polyvinyl chloride or PVC, high density polyethylene or HDPE), and frequently by a manufacturer s trade name. There is little standardisation into classes based on chemical composition or physical performance, as there is for metals. In reality, a particular chemical composition does not fully define the physical properties, while each class of performance properties can be met by a range of competing polymer types. The current trend is towards further diversification polymer compounds are increasingly being tailored to a particular application. Only in industries where recycling is an issue is there pressure for a more limited number of polymers, which can be identified and separated at the end of product life. 

As an example of another form, co-extruded blow mouldings have been introduced to the market as containers for liquid detergents. The process used is known as sandwich blow moulding and provides a means by which recycled high density polyethylene can be incorporated again into a useful form by being employed between two layers of virgin material. 

In this study, Raman spectroscopy and pattern-recognition techniques were used to develop a potential method to differentiate common household plastics by type [87-89], which is crucial to ensure the economic viability of recycling. The test data consisted of 188 Raman spectra of six common household plastics high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), and polyvinylchloride... 

At curbside many communities are collecting aluminum and tin cans, glass bottles, newspaper and plastic bottles. High-density polyethylene (HOPE) and polyethylene terephthalate (PET) are the most commonly recycled plastic bottles. Some areas that have a market for other plastics also pick them up for recycling. Sorting is done to some degree by the resident, the collector, and the reprocessor. 

An additive system was developed for poly(vinyl chloride) for medical applications. The additives include primary stabilisers (Ca-Zn stearate and Zn stearate), secondary stabilisers (epoxides) and lubricants (ethylene bisamide and high density polyethylene), to improve melt processing and heat stability. The use of the stabilisers resulted in reduced equipment down-time, increased the level of recycled material which could be incorporated, and enhanced the product characteristics, including colour, clarity, blush, aqueous extractables and particle generation. 5 refs. 

Researchers at the Chehalis facility carried out 18-months of parametric study to assess the Conrad recycling process [9]. Their objective was to identify process bottlenecks, develop operating parameters and begin to assess product value and markets. For the initial experiments a base feed mixture of 60 20 20 high-density polyethylene, polypropylene and polystyrene (HDPE PP PS) was used as representative of the major constituents found in post-consumer plastic streams. 

In the industrial field, this separation technique has been used for purposes as diverse as the analysis of odour and taste problems in high-density polyethylene [93], contaminants in recycled high-impact polystyrene [94], benzene residues in recycled polyethylene terephthalate [95] and denture adhesives [96], residual toluene in medical plasters [97], and lipstick (for assignation of products to manufacturers) [98,99]. 

HOPE high density polyethylene milk bottles, detergent bottles, mixing bowls, toys, plastic bags compost bins, detergent bottles, curbside recycling bins... 

In Delaware, this oil (4500 gal/yr) is recycled at the oil refinery at Delaware City 306 Liquid carbon dioxide is being used to take motor oil off of high-density polyethylene containers, so that both can be recycled.307 Safety-Kleen Corp. offers nationwide collection for used oil and antifreeze from cars and other sources.308 Mobile on-site services are also available for removing toxic compounds and acid degradation products from ethylene glycol antifreeze, with addition of new corrosion inhibitors, so that the antifreeze can be reused.309 Organoclays have been used to remove oils from water.310... 

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