50 | INFRASTRUCTURE
Saving the world with traffic signs Sign manufacturers could and should be using more recycled plastic in their products to reduce current unsustainable waste levels Words | David Valant, Val Plastika, Slovenia All of Val Plastika’s products, including road signs, are fully recyclable
Road signs are need to provide guidance and safety to increasing traffic. As our traffic network expands, so does the use of raw material, especially plastics. The need to recycle is increasingly important. Yet figures still show less than 7% of plastic production is being recycled and landfill is by far the most common way of dealing with plastic waste. As industrialists, we need to raise the amount of reused plastic by lowering the cost of recycling and improving the consistency of recycled material. Traffic signs generally last for decades, so it could be assumed that the contribution to plastic waste from the industry is minimal, but that would be wrong. Traffic sign manufacturers fall into a group that primarily uses new (or virgin) plastic where, in many cases, recycled material would be perfectly adequate. Production of virgin plastics alone represents 4% of annual use of crude oil and
Intertraffic World | Annual Showcase 2018
another 4% is used for its aftertreatment, transport, etc.
Closed-loop recycling challenges It is possible to closed-loop recycle most thermoplastics, however plastic packaging frequently uses a wide variety of polymers and other materials such as metals, paper, pigments, inks and adhesives. Industrial packaging is currently recycled to a greater extent than consumer packaging, as it is relatively pure and available from a smaller number of sources of relatively higher volume. The volumes of consumer waste are, however, up to five times greater than generated by commerce and industry, so to achieve high overall recycling rates, consumer as well as industrial waste need to be collected and recycled. In some instances, recovered plastic that is not suitable for recycling back to its original application is used to make a new plastic
product displacing all, or a proportion of, the virgin polymer. This can also be considered primary recycling. Downgrading refers to using recovered plastic in a way not typical for virgin polymer. For example, ‘plastic lumber’ is an alternative to higher-cost/shorter-lifetime timber. This is secondary recycling (ASTM Standard D5033).
Technically feasible but costly Chemical or feedstock recycling has the advantage of recovering the petrochemical constituents of the polymer, which can then be used to manufacture new plastic or to make other synthetic chemicals. However, while technically feasible, it has generally been found to be uneconomical without significant subsidies because of the low price of petrochemical feedstock compared with the plant and process costs incurred to produce monomers from waste plastic.
