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Comments

[vikas aggarwal]

Does the temperature gained on the surface of the BOPP film after metallising ,cause a rapid reduction in treatment? Is it necessary to have a minimum dyne level of 36 on metallised BOPP to laminate it to polyester?

[dave wilson]

How does a perm rating differ or compare to MVTR. If a customer asks for a perm rating of .02, can I convert this to an MVTR rate?

Thanks,

Dave Wilson

[Mark McGarel]

On multiple passes through the metallizer we notice various levels of oxidation on the metallized(aluminum) side of 92 gauge PET film. There appears to be little oxidation after the first pass but significant oxidation after the second. The amount of metal is a target of 2.5 optical density for each pass.
Is there a way to measure the oxidation? Is there a way to control the amount of oxidation that occurs? Can it be eliminated from the web prior to lamination?

regards;

Mark McGarel - FILMtech Inc.

[S. Levesque]

Question concerning the barrier measurement vs sampling position in a slit roll.

We metallized OPP in Aluminium deposit chamber and I observed a variation in WVTR and OTR data with sampling position in the slit roll :

1. Why barrier seems to be better more deeper in the roll than near the surface ?

2. Where is the best location to take a representative sample : on the roll "out-of-chamber" or on the slit roll ?

Thanks.

SL

[CH]

During our normal maintenance of our vacuum chamber, we recently open two of the diffusion pumps, the maintenance people notice a heavy critallized deposit at the top part of both pump. It's something we never had observed in the past. The cristallized deposit is white and oily. If you applied heat to it, it liquify.

Have you ever heard of something similar ? If yes, what can cause it ?

Thanks,

CH

[Alan Newington]

What is the polymer used to coat a plastic to improve the surface to an optical reflecting standard for aluminium vacuum depositing. Where would we be able to obtain the polymer.

Thank you

[Phil Davies]

Can you help me understand how a RGA leak tester works. and if this is a outdated system?

[Claire Poirier]

How would you measure in-line the thickness of a PVD coating (knowing its optical characteristics)? Is it possible for a roll to roll process? Do you need to have a stable distance between detector and coil? Do you know people who do that?

Thanks,

[Victor de Legarreta]

A new product requires to metallize on homopolymer polypropylene. We have tried with both corona and flame treated homopolymer, but we do not get good adhesion. of course, this film has no additives thay may harm.
Would it work with vacuum plasma? Please explain what is happening and suggest something.

[Eldridge M Mount III]

In the metallization of homopolymer surfaces it has always been difficult to obtain a high level of metal adhesion (i.e. low % metal lift on peeling). In general it is more difficult to treat the homopolymer polypropylene without degrading the polymer surface due to polypropylenes increased tendency to chain scission especially relative to polyethylene. It is more difficult to obtain “high treatment” numbers with homopolymer polypropylene so the tendency is to increase the treatment power, either watts or gas/air flow rate, for corona and flame respectively. However, this simply over treats and degrades the film surface creating a weak boundary layer which is the ultimate source of the low bond strength. So before you abandon the corona and flame completely I would lower the treatment levels and determine the optimum for adhesion as distinct from wetting. Generally, I would prefer flame treatment to corona due to the chemistry of the surface treatment and the absence of back side treatment.

In-chamber Plasma treatment does appear to improve the bonding of aluminum to homopolymer polypropylene perhaps because it captures the treated sites before they have time to degrade, but this is not known with any certainty. Generally, you will need to combine the online and in chamber treatment processes together to optimize the performance of the metal layer. So lower the on line treatment and add in chamber plasma treatment and optimize the combination to optimize the films metal adhesion performance