According to the standard of《test method for elastic recovery of knitted fabrics》, al-7000s tensile tester was used to test the elastic recovery of computer jacquard elastic belt by repeated stretch method. Set the fixed elongation to 50%, stretch repeatedly for five times, calculate the elastic recovery rate (P) according to the following formula, and measure three times to take the average value.

p=L1-L2/L1-L0×100%

Where: L0 — interval length, mm;

L1 — length of the sample stretched to the fixed elongation, mm;

L2 — length of sample after returning to zero position and stopping for 3 minutes, and then applying pretension, mm.

The test results of elastic recovery rate of computer jacquard elastic band are shown in Table 3 and Figure 6 above, and the deviation diagram of water washing is shown in Figure 7.

It can be seen that the elastic recovery rate and deviation rate of the computer jacquard elastic band have no obvious rule after washing test; the elastic recovery rate of the computer jacquard elastic band with the ratio of PET / PTT composite yarn to polyester low elastic yarn of 5:0 is the largest after washing 50 times, the deviation rate before and after washing is the smallest, and the fatigue resistance is the best.