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Hello everyone,
I'm new to this forum and pretty new to holographic embossing/embossing in general. From my understanding, to emboss holograms in a roll to roll process, a common (maybe the only, not sure) approach is to make a "master" so to speak, and then electroform it with a nickel coating to make a mother shim, which is used to create other shims. If I understand correctly, the shim is then somehow attached to a heated roller, heated up, and pressure is applied by another roller to create the embossing process. My question is, how is the nickel shim attached to the roll usually, and what sort of methods are there out there for dealing with the seam that I imagine is created? Any tips on how this works would be enormously helpful.

Thanks for all your help in advance!

Anthony

The roller that has the shim attached to it has a relief that has a clamping mechanism resessed in it. To get rid of the seam lines between holograms is a "trade secret'. It's done a few ways but rarely does anyone want to speak about it unless you buy their embosser.

Thanks for the quick reply. I can see how the seam technology could be pretty secretive. I'm curious though, if you weren't concerned with the seam for the final product, does the seam itself usually cause process problems, or is it just that the break in the pattern doesn't look right? For instance, if you were cutting into individual sheets where the cut was right on the seam, the appearance wouldn't matter, but would you have problems with shim longevity, process consistency, etc. ? Thanks again!

Hello Everyone,

You don't want shim lines because then you have to register your web. If you don't have seam lines and your doing packaging for example. A hologram that's just a repetitive pattern. With no shim lines you don't need to time the position of the material as its being applied or die cut. Anywhere you cut out a package is fine.

With shim lines you have to dance around them. Make sure they leave with the waste and are not applied to the package. You do this with various timing devices on the embosser. Different embossers use different methods. Every time you have to time something like that it slows things down, makes more splices, lots of problems.

With a "registered" image. Meaning something that has a start and end. Like a credit card holo as opposed to a gift wrapping pattern. You have to use a timing device as the die cut or the hot foil applicator has to hit the holographic web at an exact spot.

The shim is usually held with some clamps. Two pieces of metal that clamp down on the shim and then mount to gutters milled into the shim roller before its been hardened. There are also pressure rollers. There are cams on the rollers that push the rollers apart when the shim gutter comes around. That's the classic method but there are others, including seamless rollers. Shims that have no seam. They are tubes.

Jeff Weil
NorthBeach Holography Inc.