Scallops shells that once protected marine mollusks from harsh ocean conditions are now being recycled into safety clothing for the fishermen that harvest them.

In the village of Sarufutsu in Hokkaido prefecture, northern Japan, the fishing industry's biggest export is scallops, with 40,000 tons of empty shells generated annually. Large quantities of marine waste can cause unintended environmental impact, such as soil contamination, and a blighting of the landscape as mountains emerge.

Once it was realised that the main component of scallop shells, calcium carbonate, can be recycled, an alternative solution to the surplus could be realised. An upcycled material called Shelltic has been created, which is now being used for protective clothing - for the same fishermen that collect the scallops.

This is a result of an inspired collaboration between Sarufutsu village, Osaka University, plastics manufacturer Koshi Chemical Industry, and advertising agency Tbwa-Hakuhodu.

Calcium carbonate is a primary substance for many materials in the building and construction industry, but is usually extracted from rocks by intensive quarrying. To extract the calcium carbonate, the scallops shells are individually boiled and sterilised, pulverised into small pieces, and rendered into pellets. These pellets can then be melted to be used as needed.

Scallops to Shellmets

The question of how Shelltic could be best used locally was answered by exploring the connections between scallop shells and the fishing industry. Scallop harvesting is a dangerous occupation, with protective equipment needed to avoid potentially fatal injuries.

The purpose of scallop shells is the same, providing vital protection to ensure the survival of the soft bivalve mollusks housed inside. So the answer of a hardhat for fishermen emerged, and the Shellmet was invented.

Design studio Quantum brought the Shellmet to life using the concept of biomimicry, which is the concept of applying the mechanisms of nature to design and development of products and technologies. They incorporated a ribbed structure that mimics scallop shells and, along with use of the Shelltic material, improves durability by about 30% compared to standard plastic helmets.

The team can produce enough helmets for the 270 or so fisherman who live locally, and the environmental credentials of Shelltic offer up to a 50% reduction in carbon dioxide emissions compared to 100% new plastic production and a 20% reduction in emissions compared to limestone-derived eco-plastics. Scallop shells also have a natural strength and flexibility that recycled or eco plastics alone do not, giving Shelltic 30% more durability.

"Eco-plastics that meet cost, quality, and sustainability requirements are very limited at this time. We believe that it is essential to recycle more waste than ever before in order to promote a sustainable society," said Tetsuya Nambara, planning and development supervisor, Koshi Chemical Industry.

"We are pleased to be able to collaborate with the people of Sarufutsu Village and help solve the social issues in the region. We are committed to building a sustainable society that utilises waste and we hope that similar efforts will spread throughout Japan and around the world."

Shintaro Monden, product designer, Quantum said, "Shellmet's shell-like structure is designed to be both visually pleasing and functional. From material development to design, the team aimed to create a sustainable product with minimal burden on the environment, minimalistic, lightweight, and robust.

"All parts of the helmet are original designs, giving the wearer the feeling that every detail has been carefully crafted."

The Shellmet will begin its trial in Sarufutsu village in spring 2023. The collaborators are also looking to other uses for Shellmet. In recent years, Hokkaido prefecture has been hit by major earthquakes and the increased risk of disasters such as heavy rain and snow damage due to abnormal weather.

This has created the opportunity for the team to further commercialise the Shellmet for use by the general public as disaster prevention equipment but also construction work environments and for recreational activities such as cycling.

Koichi Ito, Sarufutsu village mayor said, "How to effectively use scallop shells, the treasure of Sarufutsu village, has been sought for many years. We can contribute to the realisation of a sustainable society if scallop shells can be reborn and become a helmet to protect people and the community will continue to seek ways to realise a sustainable society."