Methods and systems for preventing wrinkles in a web fed through an accumulator
Methods and systems for preventing wrinkles in a web passing through an accumulator. The accumulator comprises a plurality of rollers including at least one roller having an axis of revolution movable toward and away from the axis of revolution of another roller to release and store varying amounts of the web. At least one of the rollers has a nominally flat outer surface and at least one of the rollers has a profiled outer surface.
1. An accumulator system for preventing wrinkles in a web passing therethrough, the accumulator comprising:
a first arm that is stationary;
a second arm;
a first plurality of rollers on the first arm, wherein each roller of the first plurality of rollers is a profiled roller comprising roller shells having a generally concave profiled outer surface;
a second plurality of rollers on the second arm, wherein each roller of the second plurality of rollers is a flat roller comprising roller shells having a nominally flat outer surface and wherein each flat roller comprises a traction coating for increasing the traction of the web on the roller, wherein the traction coating comprises a plasma coating;
wherein each profiled roller is disposed between two flat rollers along a web path extending between the first plurality of rollers and the second plurality of rollers; and
wherein the second arm is movable toward and away from the first arm such that the second plurality of rollers is movable toward and away from the first plurality of rollers.
2. The accumulator system of claim 1 , further comprising:
a splicing device for splicing a web;
a roller upstream of the splicing device including an uncoated roller shell;
at least two rollers upstream of the splicing device, each of the least two rollers including a roller shell having a traction coating or traction surface; and
a roller downstream of the splicing device.
3. The accumulator system of claim 2 , wherein:
the plurality of profiled rollers is immediately downstream of the splicing device; and
the second arm pivots toward and away from the first arm.
4. The accumulator system of claim 1 , wherein at least one of the rollers is hollow; defines a largest roller diameter; and includes a roller shell thickness of 0.8% to 4% of the largest outer roller diameter.
5. The accumulator system of claim 1 , wherein at least one profiled roller is made of a composite material.
6. The accumulator system of claim 5 , wherein the composite material comprises a carbon fiber composite.
7. The accumulator system of claim 1 , further comprising a linear system.
8. The accumulator system of claim 1 , further comprising a rotary system.
9. The accumulator system of claim 1 , wherein the generally concave profiled outer surface comprises an axial cross-section with an overall shape that is curved, bow tie, V-shaped, or stepped.
10. The accumulator system of claim 1 , wherein at least one profiled roller is made of aluminum.
11. The accumulator system of claim 1 , wherein the roller shells have a largest roller outer diameter of 25 mm to 60 mm.
12. The accumulator system of claim 1 , wherein the generally concave profiled outer surface has a difference between a largest outer roller radius and a smallest outer roller radius of 20-300 microns.
13. The accumulator system of claim 1 , wherein the generally concave profiled outer surface has a difference between a largest outer roller radius and a smallest outer roller radius of 50-200 microns.
14. The accumulator system of claim 1 , wherein the generally concave profiled outer surface has a radius difference of 0.04% to 5% of a largest outer roller radius.
15. The accumulator system of claim 1 , wherein the generally concave profiled outer surface has a radius difference of 0.5% to 2% of the largest outer roller radius.