Hot rolling area of copper strip

The cut copper strip is heated at a high temperature of 1000 ℃, then hot rolled and pressed into a copper strip with a thickness of about 2.3cm. During this period, I used a stopwatch to test the time it took for the copper strip to be rolled into a blank copper strip, which was 01:47 for the first time, 01:53 for the second time, 01:59 for the third time, 01:44 for the fourth time, and 01:52 for the fifth time. The average time for each strip above is 01:51, and this step processes an average of 37 copper strips per hour.