How To Stop a Wandering Label Web

If your label placement is wandering around on your product, you may see that the label web is walking back and forth on the peel edge, or you may see that the rewind roll is spiraling one direction or the other. Either of these can be symptoms of roller misalignment in your labeling head.

First, it is important to make sure that the problem is not in the relative alignment between your labeling head and product. Watch the label web while you dispense labels into the air with no product in position. If your labeler dispenses onto a vacuum pad, be careful to give the label time to dispense completely off the web before removing it from the pad. If your label web has suddenly quit wandering, then you need to correct the alignment between your labeling head and product. Do not follow the instructions below, or you will just make matters worse. If with no product, the label web is still walking sideways, then proceed with the instructions below.

Next, let’s get the easy fixes out of the way. Check that your labeler is threaded the way the manufacturer’s instructions show. If your threading is wrong, then all bets are off. If you don’t have the manufacturer’s instructions, email me a photo, and I’ll show you the correct threading. Check to see if any rollers or other parts are wobbling around on your labeler, and if they are, tighten them and retest the machine.

Now, if we’re going to do this, let’s do it right. Line up the label web where you want it. Measure the distance from the labeler backplate to the near edge of the web along its entire path, making adjustments as necessary so the web edge is in a plane parallel to the backplate. Is the web against both the supply and rewind backing disks? If not, then bring them both into the same plane. Typically, they are held in place by either a collar underneath the disk or set screws through the hub outboard of the disk. (It is common for the supply roll disk to get knocked in from repeated slamming of label rolls into it.)

Every surface that the label web contacts must be exactly perpendicular to the backplate. Look at each roller that the label web goes around, and try to move it. Some lower-priced labelers use bushings instead of bearings, and they’ll wear out on the inside. If you can wiggle the rollers on their shafts, you may need to replace the roller assemblies.

Look at the peel edge. Is it worn down unevenly? If so, replace or sharpen it.

Look at the supply and rewind hubs. Are they perpendicular to the backplate? (Are the backing disks in line with the edge of the web?—same thing.) Some supply rolls are mounted to arms that can get knocked out of position. Loosen the mounting screws, line up the supply roll, then retighten the screws. You may find a lot of slop in the holes, so double-check that the support arm is where you want it after you have tightened it. Some rewind shafts move around in a circle. That’s okay if the center of the circle is perpendicular to the backplate.

Finally, look at the drive rollers. These are usually one rubber roller and one metal knurled roller touching each other where the label web goes through. The rubber roller is usually the drive roller that is connected to the motor; the knurled roller is an idler that is spring-loaded against the drive roller. The shafts for these two rollers must be parallel to each other. If they are just the slightest bit out, they will steer the web off a lot. The mechanism that supports the idler roller is probably behind the backplate. Look back there carefully for loose screws, broken springs, or anything else that may give an uneven pressure between the two rollers along their entire length. The roller surfaces may be worn out and need replaced.

The alignment of these two roller shafts is so critical that some labelers provide an adjustment for one of them. You have to test any adjustments here by jogging many labels through (with no product present). A small adjustment goes a long way.

Going through all of these steps should have led you to a straight label web path, which in turn should produce consistent label placement on your products. If you are still having problems, call me at 800-331-7140 or email me at jdawson@su-solutions.com, and I’ll help you find the root of your labeler problem.