DAC stands for dynamic axial compression. It combines the preparative column and packing system together. It is very simple to operate. The column can be used online when it is packed well. Don’t take the column down! Bed compression is maintained constant so that swelling will be prevented. Once particle shrinking takes place because of the solvent flow, the piston will automatically go down to let the bed maintain constant column pressure.
It can be packed with small particulate media (5 um less) so as to reach high levels of performance. For columns from 50mm to 1000mm inner diameter, the column efficiency can reach up to 40,000 theoretical plates per meter（with 10um packing material）. This requires an excellent distribution. Our engineers have innovated in the distributing groove at the column ends and designed efficient solvent distribution systems to obtain optimum theoretical plates. For the better control of the chromatographic conditions, DAC columns can be coat with a temperature jacket and/or insulation.

Specifications
Concept of the H-TREE: using the structure of large scale integrated circuit field, enforcing distribution, 8 grade H trees and level 1 grade X trees. The deal volume of the distributor is just 1% of the dead volume of the column.