Black spots appearing on tablets compressed by a rotary tablet press are commonly caused by the use of lubricating oil with unsuitable viscosity. Early imported low-speed tablet presses typically used low-viscosity oils. However, on modern high-speed rotary tablet presses, low-viscosity oil is easily flung off, leaving critical friction surfaces without lubrication protection. This leads to dry friction and the generation of metal wear debris, which then mixes into the tablets and forms black spots. Replacing the oil with one of appropriate viscosity matched to the equipment's speed and operating conditions can usually effectively resolve this issue.
At the same time, dry friction accelerates the wear of precision components such as punches and dies, further increasing the risk of black spots. We can perform single-piece or small-batch precision machining of wear-prone parts such as punches and dies for rotary tablet presses based on customer-provided design drawings, strictly controlling material selection, tolerances, and surface treatment to help customers quickly obtain highly wear-resistant, high-precision custom components, thereby reducing tablet black-spot problems caused by component wear at the source.
In daily maintenance, the lubrication system and key component conditions should be regularly inspected to ensure the equipment operates stably under proper lubrication and precise fitting.
