Every day we advise our customers about the right cap for their bottle, one able to guarantee the maximum sealing effect with an eye towards the appearance.
This request is not complex at all, but neglecting some aspects could cause various problems, both during the bottling phase and subsequently, during the use of the bottle.
In this brief article we will write about banded collar bottles, perfect for liquors and spirits. Usually the right match for this kind of bottles are composite stoppers, with natural or painted wooden head and cork or synthetic stem.
Talking about functionality, in order to obtain the strongest sealing effect, the best way is to try some sample caps directly on a full bottle. Anyway, we can start right away with some simple but effective advices to identify the right closure.
The best way to start is directly from the glassmaker technical projects (they should be attached at buying moment). The stem of the cap, may be it cork or synthetic, should be one millimeter wider than the bottle hole diameter. For example:
In this case the bottle hole diameter is 21,5 mm wide. Seen that, we would advise a 22,5 mm or 23 mm stem. These are general recommendations, but other factors can easily influence the selection, such as the conformation of the mouth of the bottle. For this reason, to avoid unpleasant surprises, we suggest to always test caps and closures on the bottles.
As regards instead to the appearances, the focus here must be put on the cap’s head. If the shape is classic, we normally suggest a diameter wide as just as the external diameter of the bottle, or slightly smaller. Referring to the picture above, our advice there would be a 34 mm head. The ideal result will be a perfectly linear bottle profile.
This piece of advice will be valid for bottles that usually match with flat wooden heads, while for other heads with different or unusual shapes the best thing to do is to evaluate the bottle-cap set.
The advices above are just simple indications given by our experience. Anyway, we suggest evaluating every time all the elements involved: bottle, cap, liquid, filling level. Moreover, if possible the best thing to do would be try at least ten samples before starting with production.