Dome

[nev25]

I'M wondering if someone could point me in the direction of how to manufacture one of these

[drcrash]

That would be difficult to do by sheet thermoforming (vacuum or pressure forming).

Tall shapes with steep sides are difficult. The plastic solidifies where it touches the mold first, and the remaining plastic has to stretch the rest of the way. That results in exponential thinning for completely vertical sides like that.

Forming it into a female (concave) mold with plug assist would help. Plug assist pre-stretches the plastic down into the mold before sucking it mostly outward onto the mold, and results in a more even plastic distribution. Still, the vertical sides would be tricky, and if you need nice optical properties---that looks like a clear display dome, where you would---it's that much harder.

Blow molding (like for soda bottles) might be good enough, but maybe somebody more knowledgeable than me about such things should comment.

(How are plastic bell-jar-type things usually made? Are the cast, blown, or injection-molded, or what?)

I'd look hard for an off-the-shelf product with the right dimensions, or something too tall that could be cut down to size. It's a pretty standard shape, so I wouldn't be surprised if there's something you could just buy.

[rickharris]

Blow molding is the commercial answer. PET usually.

IF you have access to a commercial vacuum forming machine you can try inflating the sheet before sucking down onto the pattern, this pre-stretches the plastic allowing it to drape better but deep pulls like you want almost always web as the plastic is sucked in.

[coonhunter]

you can use a vacuum box to help with the draw.
It can be thermoformed easily.

[eddygo2008]

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[Ray Layne]

It can be easily injection molded...

[AMCjeepCJ]

Pop bottles are a two stage process, they're injection molded with the threads on and there is a tube the same diameter roughly as the thread O.D. that runs about 4-5 inches down for the 2 liter variety.

The second step is they put these injection molded blanks into a blow mold and blow/suck whatever them into the shape of a two liter. If you want to see the effect a little better, cut a two liter from top to bottom in half and measure the thickness of the bottle near the top verses at the sides and notice how much thicker it is near the threads.

I have only seen the injection molded portion of this once but I'm assuming the little neck right below the threads is to keep the injection molded blank from being sucked for blown into the blow mold cavity~

Now my little friend sitting next to me ask for me to add a bouncing sheep...