If we are ever to reduce the quantity of plastics being dumped into the environment, efficient recycling is essential. Currently, many plastics cannot be economically sorted to enable their recycling. For example, many plastics contain flame retardants to increase their resistance to ignition, reduce flames spreading, minimise smoke formation and to prevent the plastic from dripping.

The amount of flame retardant added to plastics and the type used can vary considerably, due to the need to tailor the plastic to its particular application and to meet safety standards. However, only plastics of the same type and with similar flame retardants can be recycled together.

Therefore, before recycling can occur, plastics need to be sorted, not only by the type of plastic (acrylonitrile butadiene styrene and polystyrene in this study) but also by any flame retardant added. Without sorting, recycling cannot take place.

In a paper published in JSI - Journal of Spectral Imaging, an Open Access, peer-review journal published by IM Publications Open, Jose Amigo and co-authors detail a method using near infrared hyperspectral imaging and chemometrics that can sort between different types of plastic and between different additions of flame retardant.

Hyperspectral imaging collects an image of an area and, at the same time, a spectrum for each individual pixel of that image. Chemometrics is a data analysis technique that can discover hidden patterns within data (in this case spectral data) and help build a model to identify parts of the image by their chemical composition.

Using an imaging technique for this recycling application is important, since it can identify individual pieces of plastic and any flame retardant they may contain from among many others, for example, on a conveyor belt in a recycling plant.

Jose Amigo commented "Recycling plastics has been studied for many years. Indeed, some commercial cameras separating a limited number of plastic types have been available for some time. However, in this research, we wanted to go a step further to separate plastics containing flame retardants. Moreover, the proposed methodology was tested with real samples that can be found in current recycling lines."

Research paper

Related Links
IM Publications Open LLP
Space Technology News - Applications and Research

Tweet

Thanks for being here; We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor $5 Billed Once credit card or paypal		SpaceDaily Monthly Supporter $5 Billed Monthly paypal only

Engineers detail bird feather properties that could lead to better adhesives
San Diego CA (SPX) Jan 17, 2019
You may have seen a kid play with a feather, or you may have played with one yourself: Running a hand along a feather's barbs and watching as the feather unzips and zips, seeming to miraculously pull itself back together. That "magical" zipping mechanism could provide a model for new adhesives and new aerospace materials, according to engineers at the University of California San Diego. They detail their findings in the Jan. 16 issue of Science Advances in a paper titled "Scaling of bird wings and ... read more