EXTRECH UP: Formulation of sustainable polymer grades through reactive extrusion and pilot-scale validation
The project objective is to maximise the enhancement of properties in commercial grades of recycled and compostable plastic materials while reducing cost through reactive extrusion technology.
Context
The European Union’s Circular Economy Action Plan stipulates that by 2030 packaging must be recyclable, reusable, or compostable. At the national level, Royal Decree 293/2018 banned lightweight plastic bags, except for compostable ones, and Law 7/2022 on Waste and Contaminated Soils for a Circular Economy introduces two new taxes: one on non-reusable plastic packaging and another on the disposal of waste in landfills, incineration, and co-incineration, along with specific measures in the areas of prevention, waste management, and plastics. This legislation accelerates the green transition and entails the need to adapt the packaging sector to a scenario defined by sustainability requirements.
Summary and objetives
The EXTRECH UP project aims to maximise the properties of recycled and compostable plastic materials and reduce their cost through the use of reactive extrusion technology.
For this purpose, on the one hand an enhanced recycled high-density polyethylene (HDPE) will be developed by combining reactive extrusion techniques with the use of inorganic reinforcements to improve its mechanical and chemical properties, ensuring proper functionality without compromising recyclability.
In addition, the functionality and properties of compostable materials from renewable sources will be improved through reactive extrusion processing and the use of natural compounds with antimicrobial or antioxidant activity, in order to develop polymer blends that deliver superior performance without a high cost.
The project will be structured into two technological lines, with the aim of achieving the following outcomes:
Line 1: Performance enhancement of post-consumer recycled HDPE for extrusion-blow molding of hollow bodies.
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Development of post-consumer recycled HDPE grades with improved processability and properties through reactive extrusion processes.
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Production, via extrusion-blow molding of hollow bodies, of bottle-type containers using the modified post-consumer recycled HDPE grades obtained by reactive extrusion, and their validation for household cleaning (“drugstore”) product applications.
Line 2: Improvement of properties of compostable biopolymers and functionalised organic additives in blown-film applications.
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Development of blends of compostable biopolymers with improved compatibility and reduced cost via reactive extrusion.
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Production of compostable flexible film based on the developed compostable formulations using blown-film extrusion technology at pilot/industrial scale, and characterisation for packaging applications.
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Validation of the compostability and safety of the demonstrators
Initial press release
A press release was prepared to announce that the properties of compostable and recycled plastics were being improved to promote their use in, respectively, films for food packaging and bottles for household cleaning products. It can be consulted here.
Results
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Production of packaging for household cleaning products from post-consumer recycled HDPE with enhanced properties
The rheological properties of recycled HDPE fractions from different sources were improved, adapting the material to hollow-body extrusion blow moulding, as well as its environmental stress cracking resistance (up to 180 h) and its mechanical properties (an increase in elongation at break from 30% to 600–1000% and a flexural modulus of 1000–1200 MPa). Using these pellets, 1-litre containers for household cleaning products were manufactured by conventional hollow-body extrusion blow moulding. The containers proved suitable in compression and drop resistance tests.
- Development of compostable bags for bulk foods and organic waste
In the project, compostable formulations based on the compostable polymer PBAT (polybutylene adipate-co-terephthalate) have been achieved for bag applications intended for bulk foods or organic waste, with improved properties.
Regarding the results achieved in EXTRECH, tensile strength and puncture resistance have been improved, while cost has been reduced by 30%.
Press release
A press release was prepared to announce the development of packaging for household cleaning products made from post-consumer recycled HDPE with enhanced properties, as well as compostable bags for bulk foods and organic waste. It can be consulted here.
