Cutting wheels, thanks to their impact resistance, high tensile strength, and bending resistance, are widely used in our daily lives and play a vital role in the industrial world. But why do cutting wheels become brittle? This is especially true during the rainy season. How can we prevent this phenomenon?
1. Curing temperature is not up to standard or is unstable
The curing temperature does not reach the specified temperature and fluctuates significantly. Furthermore, if the raw material's technical indicators fluctuate and the required temperature is not met, then if the curing curve remains unchanged, soft filming will occur. Good curing stability means that the curing curve has been adjusted. However, if the stability drops rapidly or the weather is dry and the curing stability is not adjusted in time, soft filming can also occur on the cut piece.
Solution:
Adjust the curing curve to a reasonable and scientific level. During seasonal periods with large temperature or humidity fluctuations, adjust the low-temperature drying time and maximum curing temperature.
2. The hardening furnace is too humid
When operating, the hardening furnace is too humid and ineffective at removing moisture. Whether it's a box-type furnace or a tunnel kiln, the design of the hardening furnace must consider both air intake and exhaust. Cutting wheels release large amounts of gases (primarily ammonia and water vapor) during the hardening process. If these gases aren't exhausted promptly, they will be reabsorbed by the blade's pores as it cools down, causing the cutting wheel to soften.
Solution:
If the factory environment isn't suitable for producing resin-bonded grinding wheels, install an air conditioning system to ensure the room temperature doesn't exceed 20°C. If air conditioning isn't possible, consult with the phenolic resin supplier to adjust some of their technical specifications (primarily the gel time) to suit the hardening conditions.
3. Improper oven exit
This can be caused by rushing out of the oven or by a large temperature difference. At the end of the curing and holding period, there should be a certain cooling period to allow the cutting wheel to release evenly. If the oven exit temperature is too high or the temperature difference is too large, the cooling of the cut piece will not be synchronized, resulting in deformation and softening of the cutting wheel.
Solution:
The operator should carefully control the oven exit temperature and time to ensure the stability of the cutting disc during the curing process.
