Ball Mills

Frequently asked questions

How full should I load the grinding jar?

For dry milling a common starting point is roughly a third media, a third sample, and a third free space, so the media can cascade. Wet milling typically runs a higher media fill with liquid added to form a flowable slurry. Overfilling kills efficiency because the media can no longer tumble. Always leave headroom and follow the jar maker's fill guidance.

What grinding media should I use with a PTFE jar?

Pick media that are harder than your sample and chemically compatible, so wear does not contaminate the batch. Alumina, zirconia, and stainless balls are common; zirconia is a frequent pairing with PTFE jars where metal-free, low-contamination grinding matters. Larger media give more impact for coarse work, while smaller media offer more contact points for finer grinding and blending.

How long does roller ball milling take?

Roller and jar mills put low energy into each impact, so reaching fine particle sizes can take hours to days rather than minutes. That slow, gentle action is an advantage for temperature-sensitive materials. A built-in timer supports repeatable run cycles. If you need rapid or nano-scale reduction, a higher-energy planetary or mixer mill is the better fit.

What speed should the mill run at?

Speed is the main control variable. Too slow and the media just slide; too fast and centrifugal force pins them to the wall and grinding stops, an effect called centrifuging. The useful range is typically a fraction of that critical speed, where the media cascade. Variable-speed control lets you dial in the right action for each jar size, load, and wet-versus-dry process.