Henan Guoxin - Rotary Mold Thickness Measurement Scheme

The measurement method is a horizontal scanning method. Place the film blowing machine winding platform. Generate electromagnetic radiation film through X-rays. Measure the total thickness of 2 layers. Calculate the angle through the encoder that rotates the lower rotating mold. Through linear velocity and angle. Matrix calculation of single-layer thickness. Use comparative feedback method. Display the transverse thickness curve of the film. Corresponding circular contour diagram to the mold adjustment bolt. Easy for manual observation and adjustment.

Working principle of X-rays

horizontal curve

Thickness - Real time thickness value (mm) Setpoint - Set value Max - Large value

Min - Minimum Average - Average Spread - Mean Square Error

The horizontal curve consists of three chart display areas.

Current Profile - Real time horizontal curve, displaying data in real-time following the probe. If the data is within the alarm range, the chart will display green, such as

If the alarm value is exceeded, it will display in red. The two yellow lines in the figure correspond to the upper and lower limit alarm values set in the "Alarm Settings".

Last Profile - The chart displays the real-time horizontal curve record from the previous round of scanning history.

Average - Curve of Average Value

    This chart displays the average thickness obtained from one scan of the probe

When X-rays pass through plastic film. The difference between absorbed radiation and original radiation. Calculate the thickness of the measured plastic film.

Figure 3.7 Operational amplifier circuit 

Fig. 3.7 The operational amplifier circuit principle diagram

From the introduction of the X-ray sensor in the second figure, it can be seen that when a plastic film with a thickness of T is placed in the X-ray sensor, the simulated voltage of the sensor becomes:

Substituting the equation yields:

C = e0er1er 2 Ader2 - (er2 -er1)T（3.5）

U   = - C0U d+ C0U (1-  1 )Te0    A e0    A ex（3.6）

From formula (3.6), it can be seen that the output voltage signal U0 is linearly related to the thickness T of the plastic film [29]

Figure 3.8 Schematic diagram of X-ray sensor

Under the condition of ignoring edge effects, the operational amplifier circuit converts the feedback value to be tested into a voltage signal output, and the output signal and input signal satisfy the linear relationship shown in equation (3.6). However, due to the influence of analog signals and the nonlinear effects of the operational amplifier circuit itself, the linear relationship between the output and input is changed [30]. The relationship between output and input is:

In the formula: K=- C0e0A

Is a constant;

Uo = KUd- K (1-1 )T + f (x 2 )ex（3.7）