Injection molding with PA

Hi,

Recently we started to work with PA 678 on injection machine, and we facing to long dosage time. Sometimes is over 1 min. Only way that i found to shorten this time is by putting negative back pressure, around -10 bars, but with this back pressure we have problem with injecting different volume. Also there is not equal dosage time in each process.
Is it possible to shorten dosage time with a bit bigger back pressure so that we have constant injection?

Best regards,
Nemanja.

nemanja,

Try performing a Tact Temperature study (see attached spreadsheet), this will find the best feed zone temperature which will give you the shortest recovery time. I have used this many times and it is a useful tool. The spreadsheet is via Andy Routsis...