... 3.Shape: ball, oval,pillow... Double-roll type press machine:This machine is specially designed according to the ... abrasive, fertilizer, ceramics, etc. Ball press machine feature:1. High efficiency2. Apply for many kinds of powder like charcoal, coal, mineral, ... , high strength, and high hardnessBall press machine working principle:1. Charcoal ball press can press charcoal powder, charcoal dust, coal ...