The operation of your constant pressure system can be seen and is discussed herein in conjunction with the diagrammatical illustrations in FIGS. 2 and 3 as well as comparing together with the preceding craft system as illustrated in NO.8 STRETCH WRAPPER. As shown in NO.8 STRETCH WRAPPER, as load 78 rotates the speed at which the load rotates will vary. This is often noticed by watching the real difference in the duration of the stretchable material involving curler 84 and stress 78 between your weight situated as demonstrated by the reliable collections as well as the stress located as shown by the shattered lines. If roller 80 is power driven or rollers 84 and 82 are power driven so that the quantity of material passing around roller 84 is relatively constant during the wrapping operation then the variance in the demand for film by rotating load 78 will increase the tension on the film thereby causing significant variations in the amount of stretching of the film during the wrapping operation. Even if the machine as shown in NO.8 STRETCH WRAPPER materials the film fully based on the taking from the material by turning weight 78, due to inertia in taking the numerous roller the anxiety around the wrapping material still will vary.
Within the wrapping machine and operation from the current invention, nevertheless, this variance within the need for wrapping material with the turning weight 44 is paid for by the constant pressure process in order to maintain a constant tension about the section of stretchable wrapping material 42a and 42b simply being delivered to and wrapped about stress 44 mainly because it rotates. As shown in NO.2 STRETCH WRAPPER DESIGNING, as load 44 rotates to a position where the speed at which the load draws up the stretchable wrapping material increases, tension roller 38 moves closer to the load by pivoting movement of dancer arms 40. It supplies the extra material needed while the tension force that pulls upon the portion of wrapping material 42a extending to the load is maintained at a substantially constant level, as tension roller 38 moves closer.