Glass making process
With the emergence of float glass technology, it is possible to manufacture smooth and uniform high-quality glass in large quantities, and also make the types of deep-processed glass more and more abundant.
We will mainly introduce the glass production process is what, explain its characteristics, and especially introduce how the glass is made.
First, artificial formation
(1) Blowing, with a nickel chromium alloy blow pipe, pick a ball of glass in the mold while blowing. Mainly used to form glass bubbles, bottles, balls (for glasses) and so on.
(2) Drawing, after blowing into a small bubble, another worker sticks with the top plate, and the two people blow while pulling is mainly used to make glass tubes or rods.
Tools are made directly into crafts.
Second, mechanical forming
Because of the high labor intensity, high temperature and poor conditions of artificial forming, most of them have been replaced by mechanical forming in addition to free forming. Mechanical forming in addition to pressing, blowing, drawing, there are:
(1) Calendering method, used to produce thick flat glass, carved glass, wire glass, etc.
(2) Casting method, production of optical glass.
(3) Centrifugal casting method is used to manufacture large-diameter glass tubes, utensils and large-capacity reaction POTS. This is the injection of glass melt into a high-speed rotating mold, due to centrifugal force to hold the glass against the mold wall, the rotation continues until the glass hardens.
(4) sintering method for the production of foam glass. It is a blowing agent added to the glass powder, heated in the metal mold with a lid, and the glass forms a lot of closed bubbles during the heating process, which is a good insulation and sound insulation material. In addition, the forming of flat glass has vertical drawing method, flat drawing method and float method. Float method is to let the glass flow float on the surface of molten metal (tin) to form flat glass, its main advantages are high quality glass (flat, smooth), fast drawing speed, large output.
Third, annealing,
the glass in the forming process to undergo intense temperature changes and shape changes, this change in the glass left a thermal stress. This thermal stress will reduce the strength and thermal stability of glass products. If it is cooled directly, it is likely to break itself during the cooling process or later during storage, transportation and use (commonly known as cold explosion of glass). In order to eliminate the phenomenon of cold explosion, glass products must be annealed after forming. Annealing is the holding or slow cooling of heat within a certain temperature range for a period of time to eliminate or reduce the thermal stress in the glass to a allowable value.
