The production of laminated heat bending glass mainly goes through the following processes: glass hot bending, laminating, vacuum preheating and prepressing, high temperature and high pressure and so on.
1. Selection of hot bending mold
The molding mold used for heat bending glass plays a vital role in the process of hot bending glass forming. The types of hot bending mold are mainly divided into three kinds: solid mold, strip frame mold and hollow mold. On this basis, many manufacturers have their own characteristics in the processing of the mold. The characteristics of solid die are easy to ensure that the bending degree of glass is consistent with the spherical surface, the glass will not bend too much, and the requirements for operators are not high. The disadvantage is that the production cost of the die is high, the production cycle is long, in the process of hot bending and firing, the heat absorption of the die causes slow heating, and the pitting on the glass surface is easy to occur in the process of firing. The production of hollow die is made of Angle steel and flat steel. The production of this kind of die is relatively simple, less material, less heat absorption in the process of hot bending and firing, and there will be no pitting on the surface of the product. The operation of this kind of die requires higher technical requirements for hot bending. The strip frame die is a kind of die between the solid die and the hollow die. Compared with the solid die, its production is relatively simple, and the requirement of the hot bending operation is also low.
2. Operation process of hot bending
At present, most of the heat bending glass processing manufacturers are using electric heating hot bending furnace, this kind of hot bending furnace temperature control is convenient, easy to operate, does not pollute the glass, product quality and product consistency is high, and most have adopted computer integrated control, through the computer various parameters setting, realize the program control of the hot bending process.
The hot bending operation process can be simply summarized as the size of the matching piece, and the two pieces of glass evenly sprinkle silica powder on the concave die, and then the heating, so that the glass reaches the softening point temperature, the glass under the action of its own gravity or external pressure to reach the curvature of the concave die, stop heating, slow annealing until room temperature, so as to complete the hot bending process.
