Assuming the caliper of the material doesn’t vary across the machine, this condition usually indicates a slit quality problem. Check for improper penetration of the upper slitter blade, inadequate side pressure when engaging the top slitter to the bottom ring, or simply a dull slitter blade.
Category: Cutters
During start-up, I get as many as 10 to 15 short sheets until the line speed steadies. Once I reach this point, my sheet length control is maintained. What is causing this variation?
If your sheet length monitor reads out the proper sheet length, then the variation is caused by web slippage at the point of nip (between the squeeze roll and the draw drum). Check your roll stand for proper brake pressure. As a rule of thumb, the initial brake setting should be set so that a […]
Is it necessary to replace both the top and bottom blades even though only one appears to be dull?
Both top and bottom knives should be changed at the same time. Knives are ground separately. On stationary bed knife cutters, after setting the knives, lightly oil the blades and run the machine at moderate speed without feeding in any material. This will help to lap the knives together.
How often should sheeter knives be changed?
Knife life will vary, and depends on the material that is being cut. Most of MAXSON’s customers sheeting 0.012″ – 0.024″ thick SBS coated board are getting 1,500,000 to 2,000,000 sheets between knife changes. A machine cutting clay coated news back board (CCNB), will average 1,250, 000 – 1,500,000 sheets between knife changes.
We don’t have a squareness problem when sheeting a 50” wide roll. However, when we slit the same roll into 2 piles, 25” across, one sheet is square, while the other is not. What is causing the sheets to be out of square?
Check your draw roll section to make sure the cutter’s draw drum and squeeze roll are properly aligned. Remove the before knife doctor board to ease the ability to measure alignment. Using a plumb bob, measure the distance from the plumb bob’s line to the nearest point on the squeeze roll and the nearest point […]
I notice length variation when I sheet material. What can I do to prevent short sheets?
Short sheet lengths are usually associated with excessive brake pressure at the roll stand or inadequate nip roll pressure. See if less brake and heavier nip at the cutter’s squeeze roll remedies the problem. The surface of draw drum and squeeze roll should also be checked. If either roll is glazed or slippery, the web […]
When slitting coated paper, the sheets have dusty edges. What can be done to minimize this problem?
Slitter dust that accumulates at the center slit is attributed to misadjusted or worn slitter blades. check the settings and blade condition, replacing the top knives or bottom rings as required. Slitter dust that occurs on the outside edges of the sheet may be caused not only by dulled slitters but by the trim removal […]
During setup, the Operator sometimes has difficulty squaring the sheet. Any suggestions?
An out of square cut can be caused by a number of factors. An improper squareness setting is one possible cause for the problems. Check the setting and readjust if necessary. A web that weaves as it feeds into the cutter will also contribute to squareness problems. If this is occurring, adjust the unwind stand […]
On short cut offs, the leading edge of the sheet follows the fly knife. My operator slows down the machine. What can be done to increase speed?
It might be that the cross cutting blades are dulling, and not cutting cleanly through the web. Check the knives for sharpness or adjust for greater clash. Improper curl correction is another possible cause for this problem. If the curl is not properly treated at the decurl section, then sheets with too much “up” curl […]
