In the Middle Ages, Venice, Italy was the center of glass manufacturing. Venice glass products are novel and unique, so they sell well all over Europe and even all over the world. The glass industry in Venice has a history of more than 800 years, and its heyday is from15th century to17th century. At that time, the glass art in Venice ranked first in the world. But the secret of Venice glass manufacturing technology soon spread to France, Germany and Britain. By the17th century, glass factories had spread all over the world.
The oldest flat glass is made by pouring molten glass into a flat clay mold and cooling it, and then grinding and polishing its surface. Until the 20th century, this production process was still in use. But looking back at the history of flat glass, we will still be impressed by the wisdom of our ancestors.
Blowing glassware As early as14th century, people used iron pipes to blow glass bubbles to make small glass plates. When blowing the glass bubble, the craftsman rotates the iron pipe as quickly as possible while blowing, and the glass bubble expands outward under the action of centrifugal force to form a large disk with a relatively flat surface. Then cut it from the joint between the glass and the iron pipe and let it cool into a round glass plate.
Because round glass plates are not easy to fix, later, people used a new method to produce square glass plates. The craftsmen cut the glass tube blown into a cylinder from the middle, flattened it and let it cool naturally, thus making a square glass plate. With the continuous development of productivity, the manufacturing technology of flat glass is becoming more and more mature.
1947, the glass manufacturing process is still very complicated. To produce high-quality glass for windows, windows and mirrors, polished glass plates must be used as raw materials. This kind of glass is made by rolling molten glass flowing out of a melting furnace into a continuous belt. Because the surface of the belt is parallel to the plate bending machine, no trace will be left. But both sides of this tape should be polished, which means that a lot of glass waste will be produced and a lot of money will be spent.
In order to change the status quo, British scientist pilkington thought hard. In 1952, he had the idea of letting molten glass float on the natural smooth liquid surface. Then, he spent seven years and 7 million pounds researching a new type of glass-float glass.
Float glass is a continuous glass ribbon made by pulling molten glass out of a furnace, and the glass ribbon floats on the surface of a pool filled with tin solution. Because the molecular structure of tin is more compact than that of glass, tin solution can keep high temperature for a long time, so that the uneven part of glass floating on its surface melts, thus making the glass plate smooth and flat. Due to various natural forces, the thickness of the glass plate produced by this method is about 6 mm, which can not meet the needs of special users in the market.
Blown glassware