Old Bras wanted in Whiteshill

This is a strange one but I learn that bras that have come to the end of their supporting life are wanted for charity by Whiteshill School. It seems the bras are needed for recycling into packaging material - why bras?

School governor Gilli Williams said in The Citizen that the bras would be sent to Soroptimist International of Cheltenham and District: "The charity is raising funds to build a medical centre in the deprived village of Sika in the Gambia. Money will be raised for the project by recycling the unusable bras. Any bras that are still wearable will be donated to poor women for their own use, or to sell at market. Start spring-cleaning early and turn out your underwear drawer now."