Amazingly, only 14 percent of plastic packaging is currently recycled, leaving vast amounts to contaminate land and oceans. As much as eight million tons of plastic ends up in the sea every year, causing a great deal of damage to wildlife and even creating toxins that can enter the food chain.
More plastic recycling could significantly decrease that waste, and it could also create substantial revenues for the companies involved. At present, there are various problems with plastic recycling, including the fact that much of the material is contaminated or is composed of different materials that it is difficult to separate. Some of the plastic that would otherwise be suitable for recycling is simply too small to be easily collected. Items such as foil lined boxes, sweet wrappers and take away containers are often difficult for the plastic recycling process.
Some new technological advances have included the development of plant-based materials that can be used as alternatives to petroleum-based plastics. Unlike the conventional plastics, these new materials can be broken down without causing contamination to soil and water.
This material is commonly used for cups and packaging chips and cannot currently be recycled. Instead, it may be down-cycled into household objects such as picture frames, but new technology has identified a way of breaking down the polymer to molecules that can be sold to refiners. It can also be converted back into crude oil, but this is not currently cost effective.
LDPE or low-density polyethylene is used for grocery and Ziploc bags. It is not able to be recycled with other plastics, but many consumers still put it in their recycling bins. This can cause major problems for plastic waste recycling facilities because it can clog up sorting and conveyance machinery. A new technique known as BioCellection has recently been developed in California. This process involves breaking the low-density polyethylene down into chemical compounds in a powder form. These compounds can then be used in various ways, including as cleansers or emulsifiers in cosmetics and textile manufacturing, replacing compounds currently manufactured from palm oil or petrochemicals.
LDPE has also been targeted by Cadel Deinking’s new technology. Since logos and product information printed in colour on LDPE packaging prevent it from being recycled into film and reused for similar applications, the company has developed a process to remove the ink. The plastic is soaked in a chemical bath that is free from solvents, to remove printed on ink and it can then be recycled. This does not work for pigments that are injected into the plastic such as coloured bottle tops, so the process cannot be used for this.
Mixed material packaging
It has traditionally been difficult to recycle mixed material items, such as drinks pouches because they are made from laminated layers of aluminium foil, cardboard and plastic. A process developed by German firm Saperatec shreds the materials and puts them through a chemical bath to separate the adhesive bonds. The materials are then isolated and sorted into LDPE, polyester and aluminium for recycling.
With new technologies continually being developed, it seems likely that we will be able to substantially increase the percentage of plastics that can be recycled in the future.