Joe:

Good follow up question. To be absolutly certain of the answer I would need
to dig through some files, however I seem to recall that there were two
reasons for making the hole with a laser just before the widgets are put in
the can.

1. The widgets are blow moulded using an inert gas, probably nitrogen, if
the hole was get earlier, the nitrogen would diffuse out with the result
that air and oxygen would enter the sphere. This oxygen would subsequently
end up in the beer and cause oxidation. As you probably know, brewers are
obsessive about eliminating oxygen pickup during packaging. So waiting
until the last possible moment to make the hole is a way to limit oxygen
pick up in the package.

2. I also believe that the diameter of the hole was crucial, and they found
that the best way to get a consistent diameter was using a laser to cut the
hole.

Hope this answers your questions - iechyd da - Cwrw-42.


wrote in message
...
So what's the reason that a laser must cut a hole just prior to insertion
into the can? I don't see any explanation for that. If the other things
you say are true, then the "hole" can be manufactured at the same time
the rest of the widget is - no need for any laser on the filling line.

: Fred: