In applications such as architectural curtain walls and high-end doors/windows, the flatness and optical quality of tempered glass directly influence a building's aesthetics and user experience. Image distortion and deformation problems often seen in older curtain wall glass primarily stem from warpage and waviness during the tempering process. Luoyang LandGlass Technology Co., Ltd. has summarized four core operational essentials to help companies achieve the production of high-quality, optically superior and perfectly flat tempered glass.

1. Overall Furnace Temperature Uniformity

The overall uniformity of the furnace temperature critically impacts both glass flatness and the degree of anisotropy. Specifically, a positive vertical gradient—where the top-side temperature exceeds the bottom-side—results in upward bowing (warpage). If a longitudinal temperature gradient exists, specifically with a higher temperature at the leading edge and a lower temperature at the trailing edge can induce roller wave distortion or, in extreme cases, cause the glass to shatter during the process. These defects stem from poor overall furnace uniformity, where temperature gradients inevitably manifest as anisotropy. Anisotropy occurs as residual stress marks formed during the cooling phase. Even with highly uniform air quenching, non-uniform thermal profiles within the furnace will trigger these optical distortions. Regarding precision temperature control, LandGlass's forced convection tempering furnaces are currently recognized by the market for their superior ability to maintain a homogeneous heating environment.

2. Overall Air Quenching Uniformity

The overall uniformity of air quenching (blowing) affects both flatness and anisotropy. Non-uniform blowing will cause the glass to warp upwards or downwards, and at the same time, the non-uniformity of the blowing will inevitably manifest as anisotropy. LandGlass's Cyclone Series toughening machine utilize an innovative convection furnace chamber design, fully considering the air temperature conditions in every part of the tempering furnace, effectively ensuring overall air quenching uniformity.

3. Attention to the Flatness of Ceramic Rollers

There is a more subtle, hidden issue here: the flatness of the ceramic rollers. Although we often say that premium ceramic rollers guarantee quality, if the rollers themselves are well-made but lack precision during installation—one is high and one is low—won't that still cause wave defects? To ensure the roller's upper surface truly forms a perfect horizontal plane—where hard glass touches every point, and soft glass won't sag—and to ensure the support force provided by every roller to the glass is uniform, it requires high precision in both the roller itself and the installation process. This applies to both the furnace chamber rollers and the quenching section rollers. Because glass exiting the furnace is also soft, if the quenching rollers bend or are installed unevenly, wave defects are unavoidable.

4. Attention to the Influence of Furnace Body Vibration on Glass

During the heating and tempering process, the glass reaches a critical state, rendering it highly susceptible to deformation. At this critical phase, even micro-vibrations from the ceramic rollers can induce surface distortions as the softened glass oscillates during transport. This mechanical stability is vital for both the furnace rollers and the quench rollers. Consequently, when selecting a tempering furnace, evaluating a manufacturer’s engineering precision regarding roller drive systems is essential. While these may seem like minor technicalities, it is the rigorous execution of such details that distinguishes industry leaders from their competitors.