Maltese village feasts, festas, are a vibrant and cherished tradition, deeply rooted in culture and history. These annual celebrations, held in honour of a village’s patron saint, are a unique blend of religious devotion, community spirit and joyful festivity. At the heart of the festa, traditional decorations called liedna bring vibrant colour and festivity to the streets.

Historically, these garlands were prepared from used paper-based lottery tickets. However, in recent years, low-density polyethylene (LDPE) has become the go-to material. This material is a thermoplastic polymeric material, made from the monomer ethylene, that becomes pliable or moldable at elevated temperatures and solidifies upon cooling.

While this plastic alternative is cost-effective, it comes with environmental drawbacks – rapid degradation leading to streets covered with plastic fragments, raising concerns about pollution and litter.

Plastic pollution has become a global environmental concern, with discarded plastics accumulating in ecosystems, harming wildlife and disrupting natural processes. As plastics degrade, they break down into microplastics – tiny fragments that contaminate water, soil and even infiltrate the food chain, posing risks to both environmental and human health.

To address these issues, the Department of Metallurgy and Materials Engineering (DMME) within the Faculty of Engineering at the University of Malta was commissioned by culture minister Owen Bonnici, on behalf of the ministry for the national heritage, the arts and local government, to find a more durable and eco-friendly material for the liedna. This project forms part of a broader effort, aligning to the department’s ethos which also involves preserving Maltese cultural heritage, material selection and material development, all while embracing sustainability.

As part of this initiative, Shana N’Douri Sangana, a fourth-year engineering student from SeaTech School of Engineering, University of Toulon in France, joined the DMME team for a four-month internship. Her work, supervised by this article’s authors, focused on identifying alternative materials that could withstand Malta’s harsh climate while reducing environmental impact.

In recent years, low-density polyethylene has been used to make them.

Material selection studies were carried out using the Ansys Granta EduPack software. The aim was to find materials that were not only eco-friendly but also capable of meeting the liedna’s specific requirements, such as UV resistance to endure the island’s intense sunlight during summertime.

The selection process involved two stages: an initial global screening based on cost, carbon footprint and water usage, followed by a more detailed analysis focusing on biodegradability, recyclability and flammability. Biodegradability was prioritised to mitigate the pollution caused by plastic fragments, and non-flammable materials were preferred to avoid the need for additional fire-resistant coatings.

Prototypes of liedna made from these alternative materials are now undergoing rigorous laboratory testing, including UV-ageing tests, to assess their durability in real-world conditions.

The project not only explores innovative materials but also offers a sustainable solution to a long-standing issue, highlighting how tradition and modern engineering can merge for a greener future.

The ‘Maltese Liedna’ project represents a promising step towards preserving Malta’s cultural heritage in a sustainable and environmentally responsible way. With continued research and testing, the future of liedna may soon be both vibrant and eco-friendly.

Sophie Briffa and Anthea Agius Anastasi are lecturers with the Department of Metallurgy and Materials Engineering, Faculty of Engineering, University of Malta.

DID YOU KNOW?

•         The loud bangs of petards, or murtali, are due to rapid gas expansion from the combustion of black powder.

•         The black powder is usually a mix of charcoal, sulphur and potassium nitrate.

•         The expansion creates shock waves, which travel through the air as sound, producing the iconic boom.

• The sound can exceed 120 decibels, sometimes louder than a jet engine at take-off.

•         The pyrotechnicians must carefully calculate the size and composition of each murtal to ensure that it explodes at a safe height.

For more trivia, see: www.um.edu.mt/think.