What Are the Heating Characteristics of a Glass Tempering Furnace?

A glass tempering furnace looks simple enough to operate, but setting the heating temperature isn't what you just guess at. Even small changes in the temperature can seriously affect the efficiency of glass heats up.

First of all, you need to keep the furnace temperature within a reasonable range. Don't tweak it lightly. Once you find a setting that works, stick with it unless something changes in your glass or production speed.

Then there's the issue of residual stress. If any stress is left inside the glass before quenching, the stress can turn into breakage during the early stage of cooling-right when tension starts building up in the center of the glass. So you have to eliminate that stress completely during heating.

Also, don't set the furnace too high. If the glass gets too hot, it starts to deform. And since glass absorbs infrared energy, you need the infrared wavelength to fall right within the glass' absorption range. Otherwise, you just wasting heat.

Now let's walk through some actual heating features you'll find on a well-built tempering furnace.

1. Unique Synchronous Drive for the Ceramic Roller Table

A lot of furnaces use orthogonal belt drives to reduce shock on the ceramic rollers, but that alone doesn't guarantee perfect synchronization. When the rollers aren't turning at exactly the same speed, the glass slides relative to the rollers as it moves back and forth inside the furnace. That causes tiny scratches on the bottom surface. And if you're heating multiple glass sheets at once, they can drift out of position or even hit each other.

The fix is a compound synchronous drive: orthogonal round belts plus interconnected round belts. With this setup, each ceramic roller gets a belt wrap angle of 540 degrees and is driven by three separate paths. Even if one belt breaks, the glass quality doesn't suffer. The result is rock‑solid synchronization, better heating uniformity, and a higher yield.

2. Roller Transport Mechanism

A good furnace includes a dedicated transport mechanism for the ceramic rollers. You can remove or replace a roller without climbing inside the furnace. It's quick, clean, and cuts downtime for maintenance by more than half.

3. Advanced Insulation Technology

High‑density insulation boards plus a special anchoring system eliminate thermal shorts. That makes the insulation truly effective. At room temperature, the outer surface of the furnace stays below 50°C. If the power goes out, the furnace cools down only 150°C over 12 hours. And when power comes back, it reaches the set temperature again in just 30 minutes.

4. Roller Design That Actually Matters

The glass swings back and forth on ceramic rollers during heating. So the roller material, surface finish, and dimensions all affect heating quality. Cheap rollers leave marks or cause uneven heating. That's why high‑precision imported silicon‑based ceramic rollers are worth it. They have fine workmanship, high surface accuracy, strong resistance to bending, and a high effective load capacity. The result: fewer heating defects from start to finish.