Buzz: This question came up from a application that was using a "Blow Molding" process to produce parts. Instead of de-necking the resultant product, they wanted to end up with a hollow part that was sealed - their thought process included 'gas injection' of course to inflate the hollow section(s):
"I'm trying to find a way to close the hole made by the gas injection needle in a plastic part. This part must come out of the mold without any hole! Can someboby help me with this issue?! Thank you!"
Skippy: Ok, here's an idea, but can I have a piece of the patent?
Buzz: Sure if it already hasn't been invented before -
Skippy: Design the needle injection/retraction point through essentially a hot runner area - sequence the activity so that the needle is retracted through hot plastic after the gas injection then freeze the aperature -
Buzz: Good answer; now for the bad news, based on your small amount of feedback, a quick search of the internet based hot runner folks yielded a quick note back from the questioner - "Thank you for your cooperation!"
It seems that the quick and easy answer was to use a Gunther System (these folks already have a huge knowledge base assembled on hot runner components and applications) - information can be found at:
Skippy: glad to be of help - sometimes just a nudge is as good as a push -