Feed procurement glossary
Pellet die compression ratio (L/D)
Definition
The compression ratio of a pellet die is the effective length of each die hole divided by its diameter (L/D). A higher ratio holds feed longer in the hole, giving harder pellets but lower throughput and higher power use.
Why it matters
Two quotes for the 'same' pellet mill can produce very different tonnage and pellet quality if their dies differ in L/D, hole size or open area.
When it affects procurement
When comparing pellet mill quotes and ordering spare dies — the die must be specified per recipe, not per machine.
Example
A buyer asks each supplier to state die diameter, hole size, L/D ratio and rated t/h for each of their three recipes.
Frequently asked questions
Is there one correct compression ratio?
No. The right L/D depends on recipe, fibre, fat and pellet size; the supplier should state the die they propose for each recipe and the throughput they expect with it.