vacuum forming a honeycomb pattern

**kiltic** · 10-10-2023, 10:18 AM

Hi everybody,
I have an interesting problem. I have been, successfully, thermoforming .020" PETG sheets into a honeycomb pattern (see pics). Recently, I have discovered that .020" is too heavy for my application. .010" will work perfectly. The problem is, nobody stocks .010" PETG so I must move over to, say, .010" PC. Ok, no problem except, PETG seems to be much more forgiving and easy to form than PC. So, long and short of it is, I have been using a WARD press with heated platens and pressing the PETG with male and a female dies. I used the heat from the top platen to get the PETG hot enough to form then I pressed it. It worked great with PETG. Now, with PC, it doesn't get it hot enough to press. It seems I need to move to a UV light and vacuum table. I am not sure, however, if vacuum will be enough to draw the PC down into the holes to the bottom. In a 5/16" hole, it will need to draw the plastic down 3/8". I am curious of any of your thoughts. I am new to thermoforming and I don't want to go through building the table only for it not to work. I mean, maybe pressure forming will work better but Im not even sure where to start with building a pressure former that can form a 1'x2' sheet. Any thoughts will be greatly appreciated. Thank you so much for your time.

Sincerely,

-Connor

**peteeng** · 10-10-2023, 04:42 PM

Hi Conner - no images? Thermoforming a shape like that will require holes in the bottom of every hollow to extract air. PC is difficult to form. The temperature must be right plus it must be dry. Do you heat dry or vacuum dry your plastic before forming? Peter

**RaderSidetrack** · 10-11-2023, 01:24 AM

Conner did post two images at Industry Arena, but no images at CNCZone are a server problem.

Try these links to see the photos :

https://en.industryarena.com/forum/a...9&d=1696947327
- and -
https://en.industryarena.com/forum/a...1&d=1696947327

**kiltic** · 10-11-2023, 11:40 AM

Thank you so much for getting back to me so soon. I do not dry them before hand. I will certainly do that, however. If you have any thoughts on which is better, I would love to hear them.

I will have very small holes in the bottom of each hollow in order to pull the plastic into them. I'm just not sure if that will be enough vacuum.

Is there a better plastic I should be looking into at .010" sheet? I am obviouslty very new to all this.

Thank you so much for your help.

-Connor