Why Flap Discs Break During Grinding
Why flap disc break? We judge from where the flaps fall off and the suggested solution.
During the actual usage of a flap disc, flaps falling off may be one of the common complaints. Most of the end users' first reaction is that this is a quality problem when they see flaps fall off/break
一, The whole flap falls off from the bottom, very serious
Like the above condition, firstly, we should check if there is grinding or polishing marks.
If there is grinding marks of the flap disc, and many customer feedback about this kind of complain. The most possible reason is the the glue is not enough.
Possible Reasons as follows：
1. The tensile strength of the phenolic resin is not strong enough
If the problem exists below：
Incorrect resin mixing ratio
Insufficient glue
Contacting humidity less
Will cause the tensile strength between the flap and the backing to reduce, then the whole flap falls off under high-speed.
2. Insufficient Curing(most important risk)
The curing process decides the final tensile strength of the flap disc.
If：
Curing temperature lower
Curing time not long enough
Uneven curing furnace temperature
3. Overload grinding application
Even the quality is no problem, if under these conditions, it will also cause these complaints
Excessive grinding pressure used by forcefully
The angle grinder's power is over the rated power capacity
Long time used for heavy-duty grinding
二,The flaps fall off from the middle
Key Features：
The abrasive flap doesn't fall from the bottom of the flap disc
Breakage mostly from the middle or the upper part of the flap disc
Only part of the flaps fall off, not the entire piece of the flap or abrasive cloth
Possible reasons:
1. Over-grinding pressure
2. The grinding angle is incorrect. The grinding angle standard is 0°-15°–25°
3. The workpiece doesn't match the right flap disc
4. If the glue is too much, after the curing process. The flap root tensile strength is too much, and the flap disc is not flexible. Easy to cause breakage. If the operator uses an incorrect angle on the flap disc or uses excessive pressure, the flap may break.
The best quality of the flap disc will be like this: the consumption of abrasive grains and cloth at the same rate.
