The heating speed is a significant factor in production capacity, but uniform heating is key. What should we do when facing an uneven heating situation?
Leather processing will be taken for instance to recount it.
Out of texture and good-looking, it is necessary to emboss the surface of the leather to be closer to the appearance and feel of genuine leather. When the surface of the leather is rolled under a normal temperature, the texture is not obvious and easier to disappear. As a result, we need to heat the surface of PVC or PU leather first before embossing.
When the leather is rolled under a normal temperature, the surface texture is not obvious and is easier to disappear.
Because of efficiency and process, leathers require non-contact heating, so infrared radiation heating is the optimal option.
One of our customers told us that their embossing machine currently uses quartz lamps with a very big diameter and 1800mm in length. There were 33 pieces of lamps installed in a 2.5 *1.8 meters area, and the production speed is 4 meters per min, and it took above 40 seconds to heat the leather to 130C degrees, but actually, the ideal heating temperature is 160C degrees. Besides, the heating is not uniform. No matter how they adjust the output power of the heating tube, the temperature on both sides is always lower than the center’s, as a result, the embossing on both ends of the product couldn’t meet the performance requests.
How did the uneven heating temperature happen?
1. For a single-piece infrared lamp, due to the 1800mm long length lamp structure, the temperature in the center will be higher than at the ends. The temperature difference couldn’t be eliminated by adjusting the temperature of the lamps only.
2. For the entire furnace system, the heat loss on the outside is significantly more than in the central area, which also causes uneven temperature.
How to solve the above issues?
In order to increase the production capacity and solve the uniform heating situation, we designed and found a new heating element that is more efficient after tests, meanwhile we gave new suggestions for layout based on the new heating lamp.
1. Using medium wave infrared lamps which heating filament itself is more uniform.
Medium wave infrared heating lamps that consist of a helical wound resistance coil housed in a quartz tube will be utilized for PVC / PU leather preheating before embossing. The test data showed that it only took 14 seconds for heating leather to require 160C degrees which increases the production speed essentially, furthermore, there is no wrinkle on the leather surface.
2. Adopting medium wave infrared heaters with a customized segmented heating filament.
We can make the single-piece lamp radiate more energy at two ends by increasing the unit density of power while the center area at the lamp keeps the standard power density.
3. Employ several pieces shorter lamps replacing one long piece lamp and control these shorter lamps independently.
For example, the earlier lamp length is 1800mm, we can use 3 shorter lamps to replace, 400+1000+400mm, 2 pieces 400mm lamps will be installed at sides, and the 1000mm lamp will be installed in the center, in this case, we can realize independent controls and adjust lamps temperature.
We have perfectly solved the customer's concerns and won praise and trust from them.
If you have any demands regarding infrared heating, always welcome!