11. Experimental data for reference

For verification of the discussion on the dyeing behavior in both vapor and liquid phases, the following experiments were conducted.

Figure 6 Test dyeing machine(COLOR PET)

Test method:

The following experiments were executed using a COLOR PET test dyeing machine, under two conditions:

(1) The fabric is completely immersed in the dyebath (Photo A)
(2) One half of the fabric is completely immersed in the dyebath and the other half is in the vapor phase (Photo B)

Dyeing is carried out cyclically under the condition 1) for 10 seconds, and 2) for 50 seconds corresponding to aerodynamic jet dyeing (Figure 7).

The dyeing recipe is as follows:

Dye: Sumikaron Blue E-FBL 1.0%
Auxiliary: Leveling agent 1g/L
pH: 5
LR: 1:10
Rate of temperature rise: 2～4°C/min.
Agitation(up/down movement) : condition 1) for 10sec./condition 2) for 50sec.(cyclically)

Figure 7 Test method for levelness

When the fabric is at the upper side, half of the fabric is exposed to the vapor phase, and when the fabric is at the lower side, all of the fabric is immersed in the dyebath. Under the condition of Photo A, both a and b parts fully absorb the dye liquor for 10sec. and then keep the condition of Photo B for 50 sec.. This procedure is repeated and after dyeing, the difference of the depth is evaluated.

Test results: Under the condition of the rate of temperature rise of 1°C/min.～3°C/min. (which corresponds to the condition under which the amount of dye on the exposed part of the fiber exceeds the amount of dye being absorbed by the fiber in one circulation) there was no color difference between the exposed part (a) and the fully immersed part (b). However, when the rate of temperature rise was 4°C/min. the amount of dye on the exposed part was less than the dye being absorbed by the fiber, and unlevelness was detected. From the absorption curve in Figure 8, the absorption of dye per one circulation and the concentration of dye in the dyebath at various temperatures in the temperature rise stages can be calculated. Further, the amount of dye on the fabric in the exposed part can also be obtained from the amount of dye liquor contained in the exposed part of the fabric. The result of the dyeing test is shown in Figure 9 and no color difference is detected between part a and part b.

Figure 8 Absorption curve of dye Figure 9 Test results (dye concentration of immersed part and exposed part)

Table 4 Relation between the rate of temperature rise and unlevelness in the exposed part

Table 4 shows the test result of the comparison between the amount of dye on the fiber and the amount of dye being absorbed by the fiber (the amount of absorbable dye if there is excess dye) per one circulation under the conditions of LR=1:10, wet pick up=200% and number of circulations : once/min..

This experiment is based on the general rule that the absorption of dye per one circulation will increase by increasing the rate of temperature rise.

From Table 4 it can be explained that if the rate of temperature rise is 2°C/min. or 3°C/min. no unlevelness is found on the fabric because the amount of dye on the fiber is more than the amount of dye absorbed by the fiber in one circulation.

On the other hand, some unlevelness is found when the rate of temperature rise is 4°C/min. and it is concluded that the reason is that the amount of dye on the fiber is less than the amount of dye absorbed by the fiber in one circulation.