From the design requirements, the bottle mouth should not only meet the requirements of filling, pouring and taking the contents, but also meet the requirements of container sealing. There are three common forms of crown-shaped, plug-sealed and threaded bottle mouth structures.
(1) Crown-shaped bottle mouth The crown-shaped bottle mouth and the crown cap form a sealing structure.
The crown-shaped bottle mouth has a smaller diameter and is suitable for glass packaging bottles for liquor, beer, beverages and liquid condiments. The names and structures of the various parts of the crown-shaped bottle mouth are shown in Figure 2-47. The neck connection diameter is the size of the upper end of the bottleneck. At the same time, in order to make the bottleneck transition smoothly to the bottle shoulder and increase the strength of the bottle body, the standard stipulates that the outer diameter of the key bottleneck shall not be greater than 32mm and the inclination angle shall not be less than 45
(2) Cork-sealed bottle mouth This type of bottle mouth is to press a bottle cork with a certain degree of tightness into the bottle mouth, and rely on the extrusion and friction between the bottle cork and the inner surface of the bottle mouth to fix and seal the bottle mouth. Cork sealing is only applicable to cylindrical bottle mouths, requiring the inner diameter of the bottle mouth to be a straight cylinder with sufficient bonding length. This type of bottle mouth is mostly used for high-end wine bottles. The schematic diagram of the cork-sealed bottle mouth is shown in Figure 2-48. The corks used for the cork-sealed bottle mouth are mostly corks, plastic plugs, etc.
(3) Threaded bottle mouth Threaded bottle mouths are divided into single-head threaded bottle mouths, multi-head intermittent threaded bottle mouths and anti-theft threaded bottle mouths according to the requirements of use. Due to factors such as the properties of glass and its molding method, the thread tooth profile of the glass bottle mouth is mostly circular, with a larger pitch and fewer threads, and the opening and closing speed is faster.
1 Single-head threaded bottle mouth is a continuous bottle mouth thread (Figure 2-49). The thread has only one starting line, and the number of threads is generally 1.5~2. The screwing speed is slower than that of multi-thread, which is suitable for small-mouth bottles.
2 Multi-thread bottle mouth Multi-thread bottle mouth has 2 or more starting lines, and the interface threads are discontinuous (Figure 2-50). The bottle cap screws on quickly, and generally only needs to be screwed on 1/4 turn to tighten or open. Multi-thread bottle mouths are mostly used on large-mouth bottles and cans.
Anti-theft thread bottle mouth: The anti-theft thread bottle mouth is adapted to the anti-theft bottle cap structure. It is to add a convex ring or locking groove of the bottle cap skirt lock buckle on the structure of the threaded bottle mouth. Its function is to constrain the threaded bottle cap to move upward along the axial direction when the threaded bottle cap is unscrewed, forcing the twist-off line on the cap skirt to break and unscrew the threaded cap.