Winding onto 6" cores on a slitter with 3" shafts

A (used) 6" differential ball chuck designed to
fit a 60mm rewind shaft (once the 3" chucks
have been removed!)

I sometimes use this personal blog of mine to talk about the basics of slitting and rewinding, with the content partly led by thinking back to the questions I had when I first started working in the converting machinery industry. One of the first questions I had was 'how on earth can slitter rewinders with 3" rewind shafts be used for winding onto 6" cores?'

A lot of converters and labellers / packaging companies regularly switch between winding onto 3" (76mm) and 6" (152mm) cores, which is one of the reasons we designed our Automatic Core Cutter to change between core sizes in under thirty seconds. But what do companies who predominantly wind onto 3" cores do when they need to wind onto 6" cores? The answer is actually quite simple - they remove the 3" ball chucks and slide on 6" core chucks! There are of course several technical caveats to be observed, but on the whole switching from 76mm cores to 152mm can be very simple indeed!

Example

A customer contacts us wanting 6" differential chucks, their rewind shafts have a diameter of 60mm and their 3" differential chucks are held in place with air bladders. We supply them with 6" differential chucks with an internal diameter of 60mm.

As a certain insurance selling rodent would say 'simples'.

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