Glass bottle with a prolonged neck that continues into the inner space

[Blokle]

Is it possible to create following two shapes from glass using currently known glass mass production techniques?

Shape #1: bottle with a prolonged neck that continues into the inner space, like this (cross section):

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|           |
|           |
|           |
|           |
|___________|

Shape #2: same as shape #1 but with some circle holes in the the bottom, like this (cross section):

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  /       \
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|           |
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|   _  _____|

I'm not a mechanical engineer, but intuitively it feels like extra holes might make the production easier/possible...

1. If such shapes can be produced using current glass mass production approaches - how much more expensive (in %) such a bottle would be compared to the same sized bottle with regular bottle neck? Is it merely the extra cost of extra glass?

2. If it is impossible to create such shapes in one step - can it be made in two steps? E.g.:

2.1 create two halves of the shape (cut in the middle as on the above picture) and press them together into one shape as long as they are still hot;

2.2 create the bottle (without bottleneck) and the bottleneck separately and then press them together into one shape as long as they are still hot.

I first thought it were impossible, but then I saw that bottle (see attached images) which seems to be a more complex shape and that made me doubt...

 

[phinds]

Apparently, you'd be amazed at what glass workers can do. Your shapes are fairly trivial, I believe.

 

[Blokle]

Apparently, you'd be amazed at what glass workers can do. Your shapes are fairly trivial, I believe.

As far as I understand bottles are mass produced by blowing high pressure air into a mold filled with hot liquid glass.
So...
(a) can you really design a re-usable mold that will produce such shapes?
(b) even if yes, - how do you open the mold to get the ready bottle out of it?

Thanks.

 

[phinds]

It would be made in two pieces (your 2.2). Mass producing would likely be a pain. I was thinking of a one-off.

 

[Blokle]

It would be made in two pieces (your 2.2). Mass producing would likely be a pain. I was thinking of a one-off.

Pain, but possible?...

What do you mean by "pain"?

- More expensive?
- More time consuming?
- More fragile?

... How much more (in %)?

 

[phinds]

- More expensive? YES
- More time consuming? YES
- More fragile? NO

... How much more (in %)? YOU'VE GOT TO BE KIDDING ME. I'm not a glass worker

It would require tedious, time consuming, painstaking creation of a mold or molds and the machinery to move everything properly. For a few 100 probably quite expensive. Prorated out over many thousands, not so much.

 

[some bloke]

It is possible that you could mass produce the first one by adding a process to your machine, where it pushed the neck of the bottle in after it is blown out to fill the mould. You would get a much curvier result though. You may have to look at adding a thick stock of material at the top of the neck, which retains the heat, and having a wide rim to hold the glass in place whilst the neck is pushed in.

The other option could be to have the nozzle which blows into the glass situated further into the bottle mould (as in, where you want the exit to start) before blowing, which would form the glass around the nozzle. If you could cope with a tapered neck (tapering outwards widest on the outside) and aren't too particular on the profile around the inside of the neck this could work.

 

[Blokle]

The other option could be to have the nozzle which blows into the glass situated further into the bottle mould (as in, where you want the exit to start) before blowing, which would form the glass around the nozzle. If you could cope with a tapered neck (tapering outwards widest on the outside) and aren't too particular on the profile around the inside of the neck this could work.

Thank you very much for your ideas. Does your second option look like this?

     | |
     | |
    /| |\
   / / \ \
  /       \
 /         \
|           |
|           |
|           |
|           |
|___________|

You didn't mention anything regarding my Shape#2. Does it mean that design with additional holes is more difficult to produce?

I was thinking, maybe if the hole in the bottom is big enough - there would be a way to create a "mold inside mold" that would uphold the inner part of the neck... Maybe that mold should consist not of 2-3 parts but of 4-5 and you'll have to get them out of the ready bottle through the hole with some sort of rotational movement... Is it possible?

 

[some bloke]

My second idea would have a taper on the entire length of the neck, narrowest at the bottom (inside the bottle) and widest on the top (outside the bottle), to make the injection nozzle easier to remove. I don't know how well a blow mould would fill the shape, however - you would need to consult someone who knows more about glass than me for that!

Holes would not be easy to create in a blow mould as a blow mould requires the glass to inflate, so as soon as a hole forms, the mould stops working.

Producing a mechanical core which can exit through the neck of the bottle would be very difficult. It would also probably take more time to produce bottles than if you had a glassblower make the bottles from scratch, and would also have steps on the inside of the bottle from every join line. I suspect Glass would wear the tool down quickly as well.

In wax injection moulding we use water soluble cores to produce difficult internal shapes. There may b ea way to create a salt-based former which could withstand the temperature of the glass. I believe there are a few companies which make water soluble ceramic cores which may be suitable. You could also have it leached out with harsher chemicals, as glass is very resistant to such things.

 

[Blokle]

Thank you for all the information. Is there such thing as glass injection molding (instead of blowing)? If yes, then probably both shapes can be mass produced by dividing them into two sub-shapes - the bottle and the bottom. Both could be produced with regular simple double-mold (even holes, both in bottom and even the "bottle") and then pressed together while still hot. Is there such thing?

 

[some bloke]

I'm afraid I don't know on that one, you'll have to google it! not sure about sticking the 2 halves together though, as to make them hot enough to stick, they would probably deform.

Good luck finding out!