PET bottles have one of the highest recycling rates in the industry, although during reprocessing the polypropylene or polyethylene-based caps must be separated.
Now a California company has created all-PET caps, making it easier to reclaim 100 percent of the material in recycling.
"We identified a global sustainability challenge and an opportunity to solve it," said John Bissell, co-founder and co-CEO of Origin Materials, a manufacturer of carbon negative materials based in West Sacramento. "An all-PET bottle and cap and closure system is an obvious, necessary next step in beverage packaging and recycling.
"With our process, we can make caps from 100 percent recycled PET or 100 percent bio-based PET, unlocking important sustainability and potentially performance benefits for our customers," he added.
The new patent-pending caps can be produced from any type of PET, including recycled, bio-based and carbon-negative virgin PET produced based on Origin's technology at competitive cost.
In terms of material properties, PET also offers benefits over the use of conventional polyolefin materials, providing a better oxygen and CO2 barrier than either high density PE or PP.
The market for the new cap is potentially huge. Industry watchers, including Precedence Research, estimates the global caps and closures market was worth $65.4 billion in 2021. It is expected to top $92 billion by 2030, based on an expected growth rate of 4.4 percent between 2021 and 2030.
In addition, a cap tethering mandate
in Europe, which is due to begin in 2024, is likely to further increase the demand for Origin's innovative caps and closures. Tethering mandates require that caps remain firmly attached to bottles after opening and during the product's life cycle, with the aim of reducing plastic litter on beaches and in the ocean.
Origin Materials has developed a technology platform that uses non-food, plant-based feedstocks. The main focus is on sustainably harvested wood, although agricultural waste, wood waste or even old cardboard may be used. The platform catalytically converts C-6 cellulose into four isolated building-block chemicals in a process that sequesters carbon, the company says. One of these chemicals is CMF (chloromethyl furfural), which can be converted into bio-based paraxylene, one of the components needed to produce 100 percent bio-PET.