Pellet Rolls & Shells
Single or double rolls (also known as pellet shells) mounted inside the die ring on a cam or eccentric, turn on a rotating shaft as friction develops (due to the presence of feed between roll and die). Feed is forced through the die holes in increments so that dissection of a finished pellet shows tight layers of feed mixture. The die is driven by a motor and the rolls turn only as feed between rolls and die develops friction.
Pellet rolls specifications:See the picture on the right for actual positioning on a pellet shell.
I.D. = Inner Diameter of the Roll: The inside diameter is the most common identifying dimension of a pellet roll and is always specified during die selection.
O.D. = Overall Diameter of the Roll: The diameter of the pellet roll/shell.
W = Pad Width: The width of the pad.
The outside of the roll is the edge of the roll that comes into contact with the feed and forces the feed into the inlets of the pellet die. There are a number of different patterns / configurations of this outside edge of a pellet shell.
- Corrugated (Open end)
- Corrugated (Closed end)
- Standard (Dimple)
- Corrugated (helical, closed end)