Forming plastic with heat

[ad456]

I’m trying to put bends in plastic sheet with a heatgun(it’s really a hot work station for micro soldering). Has anyone got tips for this?

I'm not trying to create forms as such, just fairly straightforward 90deg bends and mild curves. I’ve got the gun set at about 100c at the moment. I’ll be using test pieces of Lexan, PET and ABS to practice which is probably most of the answer though I thought I’d ask to see if anyone has some wisdom to stop me wasting time and material.

[MadInventor]

90 deg bends with a tight bend radius is going to be tricky. MIld curves would be a lot easier. I would suggest making a former to bend the sheet round, fix the sheet at one end, then apply pressure and heat. There's also probably a ton of videos on youtube on how to do this. 

I used a wallpaper removal heatgun to bend ABS sheet for my War Rig roof with a reasonable degree of success, that was in the order of 1-2mm thick if memory serves.

 

[WillyChang]

Plastic when heated towards its plastic point (hehe) tends to shrink then droops as it melts. 

To have any control you need to lay it against some mold/form of intended final shape, then heat.

Hot air of most sources whether rework station or “Real Man’s Hairdryer” aka heat gun are spotty heat, not great for heating large plastic areas evenly.

To bend PLAsheet... I lay it on a corner of a wood beam or alu angle. Then heat the edge with laundry iron (dry, no steam). 

Hard to do organic curves in plastic by spot heating as reheating next area will shrink the previous area etc etc. Vac molding over former is easiest way to get what you intended to make.

Different plastics different melt points. I think lexan needed to go 130-140degC before seeing any phase change. PET was like 80ish & I could even use hot kettle water. Styrene/ABS barely 70ish. 

[Willy iine]

I use no intelligence.. place plastic into vise, clamp, then heat where you want to bend, then bend gently and use a mallet at the end.. you can quench it with some cold water in a spray bottle if you wish. 

[ad456]

I shall probably take time to make myself some forms and a mini bending break between now and Xmas and then permanently liberate one of the hot work stations from work when we finish for the year. 
 

@WillyChang “real man’s hairdryer” love it! 
the temp range is a great help too. Considering my interest in 3d printing I should’ve had the wit to look that up

 

@Willy iine I have tried that with questionable results which led me here but in time I dare say this will a go-to method

[alvinlwh]

I remember when I was in technical class, we will heat acrylic sheets in an oven. Canna mind what temperature it was set to though.