techniques in the industry to accurately achieve this moisture level sensitive moisture measurement techniques are required for example a coulometric karl fischer titration method using the brinkman model 652 rf coulometer was used successfully for verifying the desired moisture level in the formulations after blending and maintaining the moisture level the composition is converted into any convenient form for processing into film including pellets or sheets the film fabrication ca be accomplished by any convenient technique including compression molding flat film extrusion or blown film extrusion after the film is fabricated into its desired form it is then biaxially oriented by stretching by any of the well known techniques in the art including by hydraulics by pinch rolls moving at different rates or by tentering biaxial stretching can be performed sequentially or simultaneously sequential biaxial stretching is preferred when using the tentering operation another process of maintaining the desired moisture level is to employ vacuum drying in order to reduce the moisture level in too wet pellets to acceptable levels below 700 ppm and preferably below 300 ppm in this case pellets composed of polymer plus filler would be made using a water bath cooling process such that the residual moisture level is excessive these too wet pellets can be subjected to a partial vacuum preferably with some heating to speed the process for a period of time until the moisture content is within acceptable limits as defined above this process works but is not the preferred one since an extra process vacuumdrying is required yet another process of maintaining the desired moisture level is by charging the hot melt directly to the extruder which extrudes the casting from a die in this case the molten composition is never exposed.