PDA

View Full Version : Electric Heat insert cartridges to help improve knit lines..


xjcurtisx91
16th November 2015, 07:10 PM
Hello all,

We just had a mold built (A2 Diamond finish, piano black pained part). Our customer is wanting us to insert a heat cartridge in the area of the knit lines to help improve the weld so they can paint a simple mono-coat. Has anybody heard of doing this? Is it a cartridge that is controlled by voltage? Any information would be helpful!

Thanks,
Mike Curtis (Project Engineer)
rickbatey
16th November 2015, 07:16 PM
You can connect the heaters to the press and use a thermocouple to regulate the steel temperature. I've seen this done years ago on a small press instead of using hot oil. Part was from PPS.
Rick.
Suhas
16th November 2015, 10:13 PM
Yes, rick is correct.
The only point I would add on there is that the melt fronts must be hot coming into the section. The idea is not to heat the plastic back up but to keep it molten.
Hope this helps.
Suhas
JayDub
17th November 2015, 02:25 PM
You can connect the heaters to the press and use a thermocouple to regulate the steel temperature. I've seen this done years ago on a small press instead of using hot oil. Part was from PPS.
Rick.

The only problem with cartridge heaters is that they can only add heat, not carry it away. I've used them successfully with high-temp materials like PFA and PEEK, but if the tool needs any cooling they don't provide good control.
Josue
18th November 2015, 08:19 PM
yes, heater will help to improve the weld lines on the piano black parts,, I saw some molds running with a cooling device to cold down the mold and get this piano black out of flow and gates marks, but this mold use a device made in House I don't know if are available on the markets,, so, the idea its to have a time to heat the mold, and some time to let a cold water enter to cold down , and get some film to minimize the weld marks

regards
Ten Fingers
19th November 2015, 06:11 PM
Roctool offers an induction heating technology that also incorporates cooling for this type of use. I have never used it but it could be a good option for what you are looking to accomplish.

Roctool.com
xjcurtisx91
24th November 2015, 03:34 PM
Thank you everybody for the input!