UV White Ink Flaking

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UV White Ink Flaking

Postby Brownie1407 » Tue Nov 14, 2017 11:18 am

Good Day All

Has anybody had any issues with UV White ink flaking off a shrink sleeve after passing through a shrink tunnel. I am running Sericol white from Fujifilm. All quality checks performed press side & in QC lab pass however when applied to bottles (Glass & PET) and passing through shrink tunnels ( Steam & Latent) the white ink flakes off.
Various aniloxes used from 110 L/cm ( 12cm3/m2), 140 L/cm ( 8cm3/m2), 180 L/cm ( 6cm3/m2). Running on PET & PVC. I have checked lamp power, cassettes, lenses & reflectors. Changed lamps etc & still the problem persists.

If anyone can give advise on what to try next I would really appreciate it.

Regards
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Re: UV White Ink Flaking

Postby Gory » Tue Nov 14, 2017 12:28 pm

Are you new to shrink sleeve products, or have you run this ink before without issues?
Is the white you are using specifically designed for shrink sleeve application? it is quite a specialized 'niche' and ink requirements are significantly different to the requirements for general labels.
As far as lamp power etc, it is feasible you are over-curing and making brittle, assuming the ink you have is suitable for the application.
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Re: UV White Ink Flaking

Postby Brownie1407 » Wed Nov 15, 2017 4:59 am

Thanks for the reply Gory.

No, not new to shrink labels. First time coming across this particular issue. Ink supplier pointing to machine, machine supplier pointing to ink. This has only been an issue the last 4 months.

Been running for years with no problem. All systems & procedures haven't changed & routine maintenance on the press at scheduled requirements.
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Re: UV White Ink Flaking

Postby Gory » Wed Nov 15, 2017 9:04 am

Unlikely to be press, is shrink % same as previous runs? does the white overprint color and unprinted stock? if both, does it only flake from one area (flakes off color but not clear stock, or flakes off clear stock but not color)?
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Re: UV White Ink Flaking

Postby inkman » Wed Nov 15, 2017 4:08 pm

Those are good points Gory.

Sounds like too much finger pointing and not enough problem solving. No mention of film evaluation. If the ink guys say their inks haven't changed, and the press/curing units haven't changed, and the shrink tunnels are working properly, it's probably the substrate. Since the film is such a critical part of the process, I'd have it evaluated against film you know is good.
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Re: UV White Ink Flaking

Postby Brownie1407 » Thu Nov 16, 2017 4:22 am

Thanks for input. Will look into suggestions & reply.
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