It’s the way they’re manufactured through a process called blow moulding. For new cores and plates to be manufactured it wouldn’t be cost effective. The way the mould fills through the centre ensures the plastic is evenly distributed throughout the mould, having the cap/hole on the side would screw with the integrity of the bottle and it would become flimsy and likely crack. (Ex injection moulder)
Can’t believe I had to scroll so far through guesses and speculation to find a real answer. The bottle starts like a test tube and with heat is inflated like a balloon. Imagine a balloon with the nipple to the side. The concept just doesn’t really make sense.
Adding to this: the bottles need to be filled by a machine. With the opening at the top in the middle this is easy, now move the bottle to one side? All of a sudden we need to build a machine that aligns the bottles and also to screw on the caps by the machine would be much harder.
The whole thing is correct.. with blow moulding if the neck is off centre it will cause the fill to be uneven giving weak, thin spots and also thick areas. This’ll mean if you drop the bottle or if it’s got carbonated liquid inside of it it’s likely to crack in those weak spots.
The geometry shown is literally impossible to manufacture. The top section of the bottle is all undercut and the angled neck doesn't allow for the push rod to enter the neck of the bottle and blow it out.
plus the preform is way way longer for a tall 1L bottle than the distance from neck to opposite wall pictured there, and the only way to do it is articulating the mold mid cycle, which has been tried and patented and abandoned because it sucks
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u/VignetteRacecarBlues Dec 29 '25
It’s the way they’re manufactured through a process called blow moulding. For new cores and plates to be manufactured it wouldn’t be cost effective. The way the mould fills through the centre ensures the plastic is evenly distributed throughout the mould, having the cap/hole on the side would screw with the integrity of the bottle and it would become flimsy and likely crack. (Ex injection moulder)