When trying to vacuum form tall parts using a male mold may a times in the corner of the formed part the material creates a crease at the base of the part, in order to avoid this situation for many years vacuum formers have used a manual shut off valve to toggle the vacuum , in our machines we have implemented the same function in an automatic form using 3 settings in our touch screen:
Number of pulses, this tells how many times the vacuum valve will pulse.
Length of pulse, this command how long each pulse
Time between pulses, the amount of time between each pulse
Example if the settings are 3 pulses, length of pulse 1 sec, and time between pulses 1 sec. the vacuum valve will be activated for 1 sec 3 times waiting between pulses 1 sec, and the then vacuum stays open for the duration set in the vacuum length timer of the touchscreen