António Velez Marques, Helena Pereira, Rui Reis, Susana Silva
Expansion of cork through microwave radiation
Using only microwaves and water, this team of researchers developed an environmentally friendly method to boost cork's volume and attain significantly greater yields from cork harvests. The process uses a combination of moisture and heat to raise pressure and expand the material's cell walls. It is the first technique of its kind that doesn't require sophisticated machinery or use any harmful chemicals.
The cork industry relies on large forested areas for its raw materials and supports the habitat of many animal species, including several that are endangered. Cork oak trees are not cut down in the harvesting process, but their bark is removed and then allowed to grow back. During regeneration of the cork bark, the trees consume three to five times more carbon dioxide than normal, perhaps 10 tons throughout their 200-year lifespan.
The invention supports a centuries-old, traditional industry that employs tens of thousands of workers in Portugal and other cork-producing countries. The technology has helped Corticeira Amorim maintain its strong presence in the sector, generating annual sales of about €300 million and secure one fourth of the global cork stopper market.