
Whether you’re talking about plastic foam bottles, mist sprayer bottles, airless bottles, or other types of containers from www.ahpackaging.com , you often hear the term neck finish, but, what exactly is it?
Explanations and points to watch about neck finishes
The
neck is the upper part of the bottle that accommodates the cap, the
lid, the dosing pump, the trigger sprayer or the dispensing sprayer.
The closure must have the same neck finish as your bottle, jar or other container to make sure it doesn’t leak.
To
make sure you get a compatible closure for your container, choose one
of the lids shown at the bottom of the page of the container you’ve
selected.
What is a neck finish?
A neck finish is defined by a number of dimensions, including:
- the height,
- its inner diameter
- its outer diameter
- the thread, for containers with screw-on lids
The dimensions are always expressed in millimetres.
Understanding neck finish sizes
20/410, 24/415, 28/410, neck finishes...
CGMI neck finishes, corresponding to US standards, are very common.
These neck finishes are composed of two numbers separated by a fraction bar, for example: 28/410 or 28/400.
The 1st number (for ex. 28) is the OUTER DIAMETER of the neck in mm. (see "T" on the plan above)
The 2nd number (for ex. 410) refers to the thread configuration and height of the neck.

Some points to watch
All
the dimensions must match. For instance, if the height of the neck
finish on the container and the lid is not the same, the container will
not be leak-proof.
Beware
of "false friends": Some necks have commonalities or similarities that
can be misleading, so be careful (for example, a neck finish of 24/410
and a neck finish of 28/410 do not match).
Finally,
on some closures, other elements must be considered. For example for
plastic screw caps with a bore seal or for flip-top caps, the sealing
lip must perfectly match the inner diameter of the neck.
In
addition, for reducer applicator caps, if the neck diameter is too
large, the reducer won't fit and the seal will not be ensured. So it’s
important to choose an accessory that matches the container you’ve
selected.
评论
发表评论