In many production processes, it is necessary to detect perforations and leaks in injection-moulded products or films. Existing methods such as vacuum, pressure or optical control are often not applicable to transparent products or shapes that are difficult to handle. High voltage spark over can be used in a controlled way to detect perforations in these cases.
A spark over from a special electrode to a ground reference can be detected and evaluated.
Perforations in plastic webs and products can be detected and counted. Perforations in moving webs can be detected with a special detection bar and a high voltage generator. Perforations will be detected but not localised. A perforation in the film will create a spark through the material and will generate an output signal on the charging generator. Due to the strong electrical field placement of anti-static bars after the perforation detection is mandatory.
Perforations in products can be detected using high voltage to create a spark through the perforation. Common application is testing the injection point of injection moulded products e.g. yoghurt cups, bottles and containers.
Perforations in a web material can be used to determine the position of the material in the machine. The perforation can be the “tear-off perforations” of bags or a deliberate perforation made to determine a position. Perforation detection with the use of high voltage is not depending on the material surface and can also be used with transparent materials. When a perforation passes between the high voltage electrode and a ground electrode, a spark is generated. This spark will be detected and a pulse signal will be available for use by the machine control system.
Simco-Ion or a local representative is willingly to advice you if perforation detection voltage can be used in your production process. www.simco-ion.co.uk/contact