Float Glass: The Cornerstone of the Modern Glass Industry

Float glass is the world's most mainstream flat glass product. It is formed by allowing molten glass to spread and flatten naturally on a bath of liquid tin, achieving exceptional flatness and optical performance. It serves as the cornerstone of the modern glass processing industry.

Core Process

• Melting: Raw materials are melted at 1600°C into homogeneous molten glass.

• Float Forming: The molten glass flows onto a tin bath, floats on the liquid tin surface, and naturally flattens under gravity and surface tension.

• Thinning & Polishing: Edge rollers control thickness while the surface achieves a mirror finish through "fire polishing" in the high-temperature zone.

• Annealing & Cooling: Precision temperature control eliminates internal stress.

Key Characteristics

• Extremely High Flatness: Thickness tolerance of ±0.1-0.2mm, very low surface waviness.

• Optical Uniformity: Light transmittance of 89%-91%, no optical distortion or streaks.

• Stable Composition: Good compatibility with tempering, coating, laminating, and other processes.

• Flexible Specifications: Thickness range 0.5-25mm, width up to 3.6m.

Main Types

• Clear Float Glass: Fe₂O₃ content 0.08%-0.12%, slight green tint, transmittance approx. 89%.

• Ultra-Clear Float Glass: Fe₂O₃ content ≤0.015%, colorless and transparent, transmittance approx. 91.5%.

• Tinted Float Glass: Contains colorants (bronze, gray, blue, green, etc.).

Foundation for Processing
It is the base material for all processed glass products: tempered, laminated, insulating, coated, ceramic frit, and bent glass all use float glass as their substrate. The quality of the raw float glass directly determines the performance limits of the final processed product.

Main Applications
Building windows and curtain walls (accounting for over 80% of production), automotive glass, photovoltaic cover panels, electronic display substrates, furniture and mirrors.

Development Trends

• Large Format: Meeting demand for oversized curtain wall panels.

• Ultra-Thin: 0.2-0.5mm for flexible display applications.

• Ultra-Clear: Driven by photovoltaic and electronic display demand.

• Energy Saving & Carbon Reduction: Oxy-fuel combustion, waste heat recovery.

• Smart Manufacturing: Online inspection, AI-based process optimization.

Summary
Through the ingenious process of forming on molten tin, float glass achieves the ideal state of flat transparency. As the starting point of the glass processing chain, it quietly supports the visual interfaces of modern architecture and the energy revolution. It is a silent yet indispensable industrial foundation.