Thermoforming 1

[LilianaMc]

I am planning on thermo forming this half cylinder shape on a formech, and need advice on draft angles. I know male molds need a draft angle minimum of 3 degrees, is there a way I can keep this two cylinder halfs so that I can join them together afterwards that a draft angle wouldn't ruin? Thanks

 

[SWComposites]

Should be doable. Suggest you talk to a molding/thermoforming company.

 

[3DDave]

Formec is a maker of a large number of different machines, apparently starting at $64,900 (though they may mean just their factory machines.)

I would recommend extending the face of the part tangent to the surface so that the forming will extend beyond the edge of the part. This will prevent the fillet that happens inside of sharp corners from preventing getting to the exact centerline of the item.

As far as draft is concerned - you already have enough on that part for it to release any plastic. Draft is more important for flat, otherwise vertical surfaces. In sand casting draft is required for the pattern to allow release from the sand, but even in sand this part would come out without more than a tap with a small mallet.

Fun example of vacuum forming:

https://www.youtube.com/watch?v=Hiy2-L62QvU

 

[rickfischer51]

You. may be able to demold the part with compressed air

Rick Fischer
Retired Principal Engineer
Argonne National Laboratory

 

[CWB1]

Definitely talk to a mold shop or three. You may/may-not need draft depending on the method of joining the two halves and acceptability of additional features to help release the part. You might also consider molding this in one-piece if you haven't already.

 

[TheTick]

You could mirror the part, connect between, and blow-mold or roto-mold these. Get two per mold after trimming.

 

[LilianaMc]

I have updated the design, but am wondering if anyone has any resources for joining two halves of this circular design? This is my first time vacuum forming so any tips on joining are helpful!

 

[BrianE22]

Maybe vibration (friction) welding -

 

[TheTick]

You're going to join two halves of a sloppy process? Why not mold the whole thing as one piece?