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SABIC has developed resin manufacturing techniques using nanotechnology to efficiently produce more uniform polyethylene terephthalate (PET) foam, resulting in higher performance characteristics in the final product.
The new product LNP™ COLORCOMP™ WQ117945 is described by Sunamita Anunciação, SABIC’s LNP Business Development Manager, as “a breakthrough material which could expand the use of PET foams”.
Nanotechnology in SABIC LNP™ COLORCOMP™ WQ117945 helps control nucleation and results in more uniform cells with a very narrow equal size range distributed across the foam. This means that foams are lighter with smaller resin content.
Polyethylene terephthalate (PET) is one of the most used thermoplastic polymers and is used to manufacture fibers, packaging, and foams. It is beneficial as a foam where it can be used as an alternative to polystyrene or balsa wood in structural sandwich materials. PET foam can be manufactured from recycled PET bottles.
Structural Sandwich Materials
Structural sandwich materials are usually robust yet lightweight products, consisting of two stiff sheets enclosing a thick lightweight core. These materials are increasingly finding new and evolving uses in building and construction, marine engineering, packaging, and wind turbine blade construction.
In addition to its mechanical strength, PET is light, does not conduct electricity, has good high-temperature resistance, low toxicity, and is more recyclable than most of its alternatives, making it an attractive choice. The low weight of PET means it can have a lower carbon footprint than its competitors and lower transport costs.
PET Foam Sandwich Materials for the Wind Energy Industry
PET foam sandwich materials are desirable to the wind turbine industry because their low density and easy thermoformability mean that they can be used to make bigger and more complex turbine blade designs. It is estimated that in 2024, 15,000 wind turbine blades in Germany alone will need to be replaced. Many old turbine blades are currently disposed of in landfill, which is costly. Therefore, PET recyclability is a significant advantage.
PET Foam as an Alternative to Polystyrene
PET foam is an attractive alternative to polystyrene, which is traditionally used in composite sandwich materials. Polyethylene terephthalate foam is lighter, has good mechanical strength, strong insulation qualities, higher temperature resistance, lower toxicity, and is easily recyclable. It has a lower carbon footprint than polystyrene.
Balsa wood is also traditionally used in sandwich materials in wind turbine construction. PET outperforms balsa wood because it is much more uniform in structure and reacts more uniformly under stress.
Polyethylene Terephthalate Manufacture
Polyethylene terephthalate (PET) is made by polymerizing ethylene glycol and dimethylterepthalate, commonly used as clear plastic bottles. There are manufacturing challenges in producing PET foam as the melting temperature is 250 degrees centigrade. Its very narrow ideal temperature range for the foam manufacturing process, and deviation from the range will likely result in lost production. This requires a highly specialized extrusion process with very tight controls to keep temperatures stable.
SABIC LNP™ COLORCOMP™ WQ117945 helps produce more consistent nucleation in the foam, resulting in better uniformity of foam cell size. This will have the advantage of giving the foam more uniform properties and result in the use of less resin, therefore, keeping production costs down and providing a higher quality product.
Polyethylene Terephthalate Environmental Profile
PET can be recycled by converting PET products into chips and remelting them. It can also be converted back to the monomers by reversing the manufacturing process.
Japanese scientists have identified a bacterium that will biodegrade PET. In 2020, French scientists discovered an enzyme that could break down PET into monomers more quickly than the Japanese system. These discoveries should lead to even greater recyclability of PET products.
There is a demand for lightweight fuel-efficient vehicles for all forms of transport. PET foam can be used for wiper blade housings, gearbox housings, light fittings, and internal fittings. It is estimated that a 10% reduction in a vehicle’s weight can lead to a 3-7% increase in efficiency, and PET foams can be used to reduce weight in many mechanical components.
PET foams could replace polystyrene as one of the most common packaging materials as producers search for more sustainable alternatives. There will be a growing demand for recyclable, lightweight materials in packaging.
Foam can be made from new PET or recycled PET. The use of SABIC LNP™ COLORCOMP™ WQ117945 adds consistency to the foam construction and ensures uniform mechanical properties throughout the blade. Offcuts can also be recycled. The lighter blades are less expensive to transport, and at the end of their life, they can be recycled instead of being disposed of in a landfill.
The growth in PET foam usage has been slowed by the impact of COVID-19 on the economy in 2020, but this is almost certainly a temporary phenomenon. Growth is likely to resume and will be aided by government environmental policies in Europe, the USA, and Asia. The lower carbon footprint and more excellent PET recyclability will open many new opportunities for PET foams.
The corrosion resistance, strength to weight ratio, and fire resistance properties of PET foam and sandwich materials will make them increasingly attractive to the construction industry. They can also be used for their thermal insulation and acoustic reduction properties.
It is estimated that the PET foam market will grow from around US $180million in 2019 to US $335 million by 2027.
It is thought that the fastest growing market will be Asia, followed by Europe and North America.
In 2020, approximately 50% of all composite foam products used PVC foams, which are challenging to recycle. Armacell International, DIAB Group, Gurit Holding, 3A Composites, Sekisui Plastics. Co. Ltd., and Carbon Core Corporation are key companies leading the global PET foam market.
The Future of SABIC’s Nanotechnology
SABIC’s new nanotechnology LNP COLORCOMP WQ117945 could have additional applications beyond high-density PET foams. It can be used as a rheological modifier for improving melt strength and thermoformability. The special properties of LNP COLORCOMP WQ117945 are described as “resin agnostic”, which means that it could also be used with other resins and in other industries.
References and Further Reading
SABIC (2021) SABIC’S NEW, BREAKTHROUGH LNP™ COLORCOMP™ COMPOUND USES NANOTECHNOLOGY TO ENABLE DIFFERENTIATED FOAMS. [Online] Available at: https://www.sabic.com/en/news/26227-sabics-new-breakthrough-lnp-colorcomp-compound-uses-nanotechnology (Accessed on 9 February 2021).
Omnexus (2021) SABIC Introduces Nanotechnology-based Resins for PET Foams Production. [Online] Available at: https://omnexus.specialchem.com/news/product-news/sabic-resins-pet-foams-000223656 (Accessed on 9 February 2021).
Mordor Intelligence (n.d) POLYETHYLENE TEREPHTHALATE (PET) FOAM MARKET - GROWTH, TRENDS, COVID-19 IMPACT, AND FORECASTS (2021 - 2026) [Online] Available at: https://www.mordorintelligence.com/industry-reports/pet-foam-market (Accessed on 9 February 2021).
Transparency Market Research (2020) PET Foam for Structural Composites to Replace PS Foams in Near Future. [Online] Available at: https://www.transparencymarketresearch.com/structural-composites-pet-foam-market.html (Accessed on 9 February 2021).
FOAM EXPO Europe. (n.d) Is it really that difficult to produce PET foams? [Online] Available at: https://www.foam-expo-europe.com/home (Accessed on 9 February 2021).