Depending on the complexity of your manufacturing equipment, it may not be possible to check every surface, roller, etc. that the film touches.
Two things in your favor:
1. You probably are a dry manufacturing environment that does support microbial growth.
2. Plastic film does not support microbial growth.
As mentioned above, if you do random swabbing to show no hazardous levels of harmful microbes, then you indirectly show no contamination for any surfaces that had been contacted by the film. A 3rd party lab should be able to advise what frequency would be sufficient.
They should be able to suggest a reduced testing frequency after you have shown a trend of negative results.
There will be microbes present on all surfaces, including skin and clothing, but it usually is below a hazardous level. This is probably why Charles C. raised the question about what standard you are referencing.
Although their might be no bacteria after extruding, the bacteria that is in the air will eventually settle on any exposed surface of equipment or product. This implies that you should be covering your film during storage, and covering machines during any maintenance that may spread contamination onto the equipment.