Make sure there is adequate belt tension in the bottom slow speed tape section, so that the weight of the sheets does not cause any excess drooping. Adding an edge turner between the two streams in the slow speed tape section prior to the stacker will also help to split the two piles. A final […]
Author: Scott
I have an automatic pile lowering feature on my stacker. When the pile lowers, the sheets skew, causing an unevenly jogged stack. How can I improve pile quality?
Your problem could be caused by the following: One of the jogger blades is lower than the other. Set all jog blades to the same depth. The load table’s guides are loose or worn. If the table sways when rocked, inspect the guides and address accordingly. The front to back jog box may be misaligned. Make […]
When sheeting light weight board, the sheets have a tendency to turn under at the edges entering the stacker. What can I do?
Try to give the sheet some added rigidity by using edge turners and crimpers. Edge turners (or “shoes”) flare the edges of the sheet in the delivery system. Crimpers are placed in the center of the web path to corrugate the sheet, giving it added stiffness. When using edge turners and crimpers be careful about […]
When sheeting paper at higher speeds, the sheets roll over in the pile. To compensate, my operator reduces speed. Is there another way to solve this problem?
Your pile height may be too low. Ideally, the gap between the top of the pile and deliver roll should only be ½ to ¾ of an inch. Raise the position of the feed down sensor so the sheets can fall freely into the stacker. If this does not correct the problem, try adding air […]
In the stacker, we experience turned up edges on the sheets. What causes the sheets to fold this way?
Turned up edges are caused by too much up curl in the web. Adjust the amount of decurl accordingly until you get a flat sheet. Turned down corners can be the result of not enough bottom delivery tapes supporting the sheet. This occurs most frequently along the slit edges of the sheet. Move the bottom […]
The sheet packet hits the stacker front stops too hard, damaging the leading edge of the sheet. Besides slowing down the sheeter, is there anything I can do?
Sheet damage can be prevented by increasing the amount of overlap. This is done by reducing the speed of the slow speed tapes (either adjusting it mechanically through the a gearbox or electrically through a motor). When sheeting easily damaged or soft material, consider applying rubber to the front stop boards or fingers to absorb […]
I am having trouble with delivering and stacking certain materials because of static. Is there anything I can do to my existing sheeter to overcome this problem?
Humidity Humidity affects static build up. “Relative humidity” is the percentage of moisture held in the air compared to the maximum it could hold at that temperature. The reason static is more problematic in cold weather is because of low humidity of the air. If the relative humidity drops below 30%, the static conditions become […]
When sheeting carbonless paper, the sheeted stock sometimes wraps around the cutting section. Once we get past this point, we also have difficulty stacking. Do you have any suggestions?
It would appear that static is the cause of most problems. There are several things you can try to prevent material from wrapping around the knife cylinder: Wrap the cylinder with a felt or short nap non-conductive material. Introduce compressed air above the doctor board between the rubber covered nip roll and the knife cylinder. […]
We have a problem when running light weight label stock. The sheets have a tendency to skew in the tape system, and this damages the corner of the sheet as it hits the stacker’s front stop. What can I do to alleviate this problem?
Here are a few suggestions: Check your tape tension to make sure it is the same across the width of the delivery section. You may want to set the lower tapes tighter to support the sheet. Make sure the pinch of the overlap carriage or “stop” wheels are set properly. The nip should be snug […]
We recently sheeted an order of coated paper, and had lots of problems due to static. Do you have any suggestions for sheeting coated stock?
If the problem is in the cutting section, such as the web wrapping around the squeeze roll or the knife revolver, an old trick is to mount a cotton felt across the infeed of the sheeter and then wet it. The dampness of the felt will help to neutralize static, and prevents jam-ups in the […]
