Cork, generally referred to as the oak bark of the deciduous tree of the genus Fagaceae. The cork tree is one of the oldest tree species in the world and is about 6,000 years old.
The world’s first discovered “cell” was derived from cork. As early as 1665, British scientist Robert Hooke observed the structure of a piece of cork with a homemade compound microscope and found it to be made up of many honeycombs. The composition of the chamber and the type of honeycomb cell is named “cell”. After the cross section is magnified by the microscope, it is known that cork is composed of a number of flat cells arranged in a radiation, with 40 million cells per cubic centimeter of cork. The cork cell cavity contains resin and tannin compounds and is filled with a mixture of air-like gases to form a closed balloon.
Cork is typically 4 to 5 cm thick and high quality cork is 8 to 9 cm thick. The oak tree is generally grown for 25 years, and the tree circumference is 70 cm. The first time the stripping is carried out, generally in the most active oak period from May to August, the stripped oak bark will naturally regenerate, and every Pick and peel once in 9 years. The softwood harvested for the first time is called “primary harvesting cork”, and after 9 years it is again harvested as “recovered softwood”. Each peeling will not only damage the oak, but will promote its growth, and the longer and thicker the bark. Portugal still uses the most primitive and professional artificial cork mining and stripping method. The harvesting height is more than 1.3 meters. After the stripping, each tree will be marked with the current year, in order to prepare for the next time.
