Showing posts with label blow molding. Show all posts
Showing posts with label blow molding. Show all posts

Thursday, November 1, 2007

There's (often) 'not much new under the sun'

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:

http://www.guenther-hotrunner.com/php/start.php?lang=us

http://www.guenther-hotrunner.com/Download/Katalog/englisch/KAP-01-02-()-EN-NEEDLE-VALVE-TECHNOLOGY.pdf

Skippy: glad to be of help - sometimes just a nudge is as good as a push -