Boiling strips: boiling is the first step in the process. The strips are bundled together and boiled twice. This cleans the cork, removes water-soluble substances, increases its thickness, reduces its density and makes the cork softer and more elastic.
Resting: after boiling a resting stage begins in which the strips flatten so the cork has the consistency required to turn it into stoppers.
Strip selection and cutting: the edges of the strips are prepared and cut prior to initial manual assessment. The strips are divided into quality classes and cut into thinner strips.
Punching and drying: the strips of cork are punched with a hollow drill bit to produce a cylindrical stopper of the desired size. Drying takes place, to stabilise the stoppers until they reach the ideal moisture level.
Size adjustment: adjustment begins after the corks have been punched out. This is done to make them the specified size and standardise the stopper’s surface.
Stopper selection: stoppers are divided into classes by automatic selection machines and manually too.
Washing stoppers: the washing stage involves cleaning, dusting and disinfecting. They are then dried to ensure optimal sealing performance.
Marking: this is done in accordance with the customer’s instructions. The text and/or logo is printed on the stopper’s surface. The marking may be printed with ink or burnt on the stopper.
Surface treatment: the cork stoppers are treated with a mixture of silicone and paraffin to make it easier to insert and remove the stopper from the bottleneck and improve insulation.
Packing: after the softener has had sufficient time to be fully applied, the stoppers are packed in thousand-unit bags that are vacuum-packed and treated with sulphur dioxide.
Transport: domestic and international orders are delivered to the address provided by the customer. Imperial Cork is responsible for the entire delivery process, administrative procedures, customs and handling to make it as convenient as possible for customers.