6. The ratio of area exchange in jet dyeing

In a dyeing machine where the material transfers, such as a jet dyeing machine, the effective area is not a fixed one, but the volume of a dyeing vessel can be considered to be the effective area where the material can transfer and expand.

Here, in the case where the dye liquor in the vessel can fully circulate;

Effective area=Area (volume) where the material can transfer and expand

Then, this value can be regarded as the maximum of the effective area.

Figure 2 Effective area in the jet dyeing machine
	Fully immersed type

In practical dyeing, liquor circulation by pump and material circulation by liquid flow are executed simultaneously, and both are effective for level dyeing. However the effective area in jet dyeing can be expressed by the following equation because the liquor circulation by pump is more effective.

Effective area in jet dyeing=Volume of dyeing vessel×Number of dyebath circulations (5)
Ratio of area exchange in jet dyeing=Ratio of effective area×number of fabric circulations(times/min.) (1')

Ratios of area exchange for 3 types of jet dyeing machine are shown in Table 2.

It can be said from Table 2 that the ratio of area exchange of conventional jet dyeing machines is similar to that for conventional cheese dyeing machines, and level dyeing can be obtained with the same temperature rise regardless of dyeing machine, which is experimentally known in the industry.