Two critical factors influencing quality of tempered glass

Roller wave distortion and edge lift are two critical factors that influence the quality and performance of tempered glass products.

Here’s a summary of each:

1) Roller Wave Distortion:

- During the tempering process, heated glass sheets become pliable, requiring support from rollers within the furnace. Uneven pressure distribution from these rollers can cause the glass to warp subtly, akin to a gentle wave. As the glass cools and hardens, this warped state becomes “locked in,” manifesting as a characteristic wavy pattern across the surface.

2) Edge Lift:

- Unlike roller wave, which affects the entire surface, edge lift refers to the curvature of the glass edges themselves, either upwards or downwards.

# Causes:

- Smaller diameter rollers can concentrate pressure, leading to more pronounced wave formation. Uneven wear or misalignment of rollers can also exacerbate the issue.

- Uneven pressure from rollers during tempering can cause the edges to be pushed up or down.

- Thinner glass, with its reduced rigidity, is more susceptible to sagging under its own weight during the high-temperature phase, contributing to a more pronounced roller wave and edge lift.

- Improper heating or cooling profiles can influence pressure distribution and potentially worsen roller wave.

# Impact:

- Visual Distortion: The wave pattern disrupts light transmission, leading to a loss of clarity, particularly noticeable in reflective applications.

- Aesthetics: Roller wave detracts from the visual appeal of the glass, making it appear wavy or uneven, a significant concern in architectural glazing and display cases.

- Functional Issues: In severe cases, edge lift can affect proper installation or performance. For instance, during installation, glass with significant edge lift might not sit flush against a frame, creating uneven gaps and potentially compromising structural integrity. Additionally, in laminated glass applications, excessive edge lift can hinder the laminating process and potentially weaken the bond between glass panes.

# Minimizing Imperfections:

- Optimizing Process Parameters: Fine-tuning heating temperature, duration, and roller configuration for specific glass types can significantly decrease these distortions by ensuring uniform pressure distribution and minimizing warping.

- Furnace Maintenance: Regular inspection and replacement of worn rollers are essential for maintaining optimal roller performance and minimizing uneven pressure.

- Glass Selection: Choosing glass with a higher softening point can be beneficial for critical applications where roller wave and edge lift are of paramount concern.

Post time: Apr-08-2024