One of the barriers to widespread adoption of bioplastic in food and drink packaging is that there is no national, or even many regional, systems for collection and disposing of bioplastic in compost facilities.
Natureworks, maker of polylactic acid-based Ingeo bioplastic, has found, though, that bioplastic can be sorted out of recycling streams effectively. One concern with consumers disposing of bioplastic in recycling bins is that the bioplastic could contaminate the materials it's mixed with.
Over the past two years, Natureworks surveyed equipment manufacturers that had the potential to sort bioplastic from other plastics like PET, HDPE and PVC using infrared, ultraviolet, x-ray, color identification and laser sorting. Natureworks identified a dozen companies and then worked closely with three of them to find out how accurate the sorting systems are.
Titech's near-infrared sorting systems removed Ingeo plastic from a PET sorting stream at an accuracy of 97.5 percent, about as effective as removing contaminates and other items unwanted in the PET stream. Unisensor's laser technology was 96-99 percent effective at removing Ingeo flakes from PET flakes. MSS also used a near-infrared system on Ingeo, finding the bioplastic emits a unique polymeric signature that the system can be programmed to identify and remove.
Although bioplastic has a long way to go before it's used in as many bottles as PET is, some companies have already switched over. Within the last year, three water companies throughout the world have adopted Ingeo-based bottles: North Carolina-based Primo Water Corporation, which had conducted a five-month, 2 million bottle pilot project of Ingeo bottles, New Zealand's Good Water and Sant'Anna mineral water in Italy.
Taking bioplastic out of the recycling stream is one step. What's also needed is a system to collect that bioplastic and compost it, a task being looked at by a number of groups, including the Bioplastics Recycling Consortium.
Bottle photo - CC license by Autumn Welles