Ordinary transparent glass can be divided into ordinary clear glass and ultra-clear glass according to the material. Both can be tempered. Let's take a look at how to distinguish between ordinary clear glass and ultra-clear glass. What is the difference?

The differences between ultra-clear glass and ordinary clear glass lie in their clarity, UV transmittance, production process, price and glass stability.

Differences in composition and production process

• Iron content

The key feature of ultra-clear glass is its extremely low iron content (Fe₂O₃ mass fraction does not exceed 150×10⁻⁶), which is only 1/10 of ordinary glass or even lower. This low-iron formula reduces impurities in the glass (such as nickel sulfide), thereby improving transparency and stability.

Ordinary cglass will appear green when observed from the side due to its high iron content, while ultra-clear glass will appear light blue or almost colorless.

• Difficulty of production process

The production technology threshold of ultra-clear glass is high, and the purity of raw materials and melting process must be strictly controlled. Currently, only a few companies in the world (such as Saint-Gobain of France, Asahi Glass of Japan, and China Southern Glass of China, etc.) have mastered its core technology. The production process of ordinary glass is relatively mature and the cost is lower.

Comparison of appearance and optical performance

• Color and transparency

Ordinary glass: Due to iron impurities, the side is green, and the light transmittance is about 80%-85%.

Ultra-clear glass: Almost colorless, with a light transmittance of more than 91.5%, and a visual effect similar to crystal, especially suitable for scenes with high requirements for color reproduction (such as museum display cabinets and viewing windows).

• Ultraviolet protection

Ultra-clear glass has a lower absorption rate for ultraviolet rays, which can reduce the fading of indoor items, so it has more advantages in cultural relics protection and high-end buildings.

Physical properties and safety

• Self-explosion rate

The self-explosion rate of tempered ultra-clear glass is only about 0.01% (one in ten thousand), which is much lower than the 0.3% (three in a thousand) of ordinary glass, thanks to its less impurities and uniform composition. For large-area glass curtain walls or high-rise buildings, the safety of ultra-clear glass is significantly improved.

• Stability

Ultra-clear glass has better thermal stability under temperature changes and is suitable for extreme climate environments. Ordinary clear glass may have ripples or bubbles after long-term use due to uneven composition.

Price and economy

The price of ultra-clear glass is 1-10 times that of ordinary clear glass (the specific multiple varies depending on thickness and processing technology). The reasons for the high cost include raw material purity requirements, complex production processes and technical barriers. Ordinary glass is more cost-effective and suitable for scenes with limited budgets or no strict requirements on transparency (such as partitions, ordinary doors and windows).

Applicable scene recommendations

• Ultra-clear glass

High light transmittance requirements: such as floor-to-ceiling windows, skylights, and observation decks, which need to maximize natural lighting.

High safety requirements: high-rise buildings, large glass curtain walls, to reduce the risk of self-explosion.

Aesthetic design: minimalist style homes, museums, art exhibition halls, to avoid green interference.

• Ordinary clear glass

Indoor partitions with low light transmittance requirements.

Ordinary doors and windows with limited budgets and no need for long-term UV resistance.