Container Handling & Change Parts

Container Handling: Control the Bottle, Control the Label

No amount of glue control will save a label that is applied to a container that is not being held straight. Centering bells, centering head assemblies, bottle plates, starwheels and guides exist to present the container to the labeling station in exactly the same position every cycle. When that stops happening, the label placement drifts and the reject rate climbs.

Centering bells and heads

Centering bells take a lot of abuse. The pad wears, the bell body gets scored, and the spring assembly loses the pressure it needs to hold the container down against the plate. The result is a container that can rock or rotate a few degrees during application, which reads as crooked labels even though the labeling station is working perfectly. Bells and centering head assemblies can normally be rebuilt with new pads, bushings and springs rather than replaced outright.

Bottle plates and change parts

Plates and starwheels are container-specific. If you have added a new bottle size or switched suppliers and the profile changed slightly, the existing change parts may no longer locate the container correctly even though nothing has worn. This is one of the most common causes of a labeling problem that appears overnight with no maintenance event behind it.

Diagnosing it on your line

• Run the line slowly and watch whether containers rock or rotate under the bell
• Check whether the defect follows specific pockets around the carousel
• Compare a suspect bell against a known-good one for pad height and spring travel
• Note whether the problem tracks a particular container size

If the defect follows specific pockets, it is almost always a worn part in those positions rather than a machine setting. Send us what you find and we will quote the rebuild or the change parts you need.