When packing certain web materials it is important to roll the web consecutively on top of the previous portion of the web. This sometimes is difficult due to trapped air between web layers. To reduce this air entrapment effect do the following:
Encase the take-up roll providing a slit in the encasement for web entry. Place high vacuum nozzles at both edge sides and a flat vacuum nozzle at the intercept wrapping point of the roll up. Try to obtain enough negative pressure within the case so that the air entrapment effect is minimized. (See Figure 1for details.)
There are many processing tools and techniques for processing surface and edge of certain types of web material.
The cleaning or lapping film technique:
Using cleaning or lapping file (variety of grid types available) an edge or surface can be improved and a reduction of web defect can be achieved. Using a pipe that is cut length wise down the center (see Figure 2), cut a rectangular piece out of the ½ pipe so the web edge is visible and can be processed. You can now place any of the processing tools found in Figure 3 on a station to clean or process the edge of the web as the web passes through the ½ pipe. I have included a hot or cold pinch roller system before or after the slitting knife or process stations. Finally there are air jet nozzles that can also be used for edge process and or cleaning providing that you have a collection trap for the debris.