Jul 19 , 2025
In the manufacturing of hot bending glass, molds are critical tools that determine the shape and surface quality of the final glass product. Traditional metal molds can easily deform at high temperatures and have high thermal conductivity, which hinders precise temperature control and energy efficiency. High-density calcium silicate boards, with their exceptional high-temperature resistance, dimensional stability, low thermal conductivity, and ease of machinability, have emerged as an ideal material for crafting hot bending glass molds.
High-density calcium silicate boards are typically machined into various complex mold shapes. These molds are used to heat flat glass to its softening point, allowing it to bend and conform to the mold's shape under its own gravity or external pressure. These molds can be utilized in both continuous bending furnaces and batch bending furnaces.
1. Excellent High-Temperature Performance: Hot bending glass requires processing in high-temperature furnaces, typically ranging from 600°C to over 800°C (1112∘F to 1472∘F). High-density calcium silicate boards can withstand these extreme temperatures without decomposing or deforming during prolonged use.
2. Superior Dimensional Stability: This is key for manufacturing precise molds. Through repeated heating and cooling cycles, high-density calcium silicate boards maintain extremely low linear shrinkage and expansion rates, ensuring the mold's shape and dimensions remain consistently accurate. This, in turn, guarantees the precision of the hot-bent glass products.
3. Extremely Low Thermal Conductivity: The material's low thermal conductivity means heat does not rapidly transfer from the furnace through the mold to its underlying support structures. This promotes more uniform temperature distribution within the furnace, facilitating even heating and precise shaping of the glass, while also reducing kiln energy consumption.
4. High Strength and Durability: High-density calcium silicate boards possess good compressive and flexural strength, allowing them to withstand the pressure exerted by the glass during softening and bending. This prevents breakage and ensures a long service life for the molds.
5. Non-Reactive and Non-Adherent to Glass: With proper treatment, the surface of high-density calcium silicate boards exhibits excellent non-adherence to molten glass. This prevents the glass from sticking to the mold during the forming process, ensuring a smooth glass surface and reducing the need for post-processing.
6. Easy Precision Machinability: This material can be easily cut, milled, and carved using precise machining equipment like CNC machines. This allows for the creation of complex three-dimensional mold shapes, meeting the customized needs for various automotive glass, architectural glass, and appliance glass products.
7. Lightweight Property: Compared to traditional metal or heavy refractory materials, molds made from high-density calcium silicate boards are significantly lighter. This facilitates easier placement and removal by operators within the furnace, reducing labor intensity and operational risks.
High-density calcium silicate boards, as a material for hot bending glass molds, significantly enhance the production efficiency and product quality of hot-bent glass. This is due to their stability at high temperatures, precise dimensional retention, excellent insulation properties, and ease of machinability, making them a crucial innovation in modern hot bending glass manufacturing.
