The tamper-evident seal is achieved by a glass ring sitting right below the screw thread. The tamper-evident ring of the cap goes over this glass ring when the closure is installed. During the initial opening, the tamper-evident ring of the cap is broken off making visible if the container has been opened before.
This type of tamper-evident closure is widely used, not only in drinking bottles made from PET but also in pharmaceutical packaging where the integrity of the content is mandatory. Both PET and glass containers have one common feature: they are moulded.
In the moulding process, the raw material is heated to the required temperature and then moulded into the required form. Glass is either blown or pressed and blown in this process. The use of compressed air to form the inside shape of the container results in an uneven wall thickness. The distortions caused by the uneven wall thickness becomes visible when the moulded glass container is held against a source of light.
Due to the production process, moulded glass cannot be fitted with an optimised microsampling feature. Likewise it is not possible to add such a feature to a moulded glass container after the initial production. To reshape a glass container, the glass needs to be heated evenly which is not possible when the wall thickness is uneven.
GTG developed and patented a production process which allows the inclusion of a tamper-evident seal in a tubular glass vial.
Customized dimensions are possible for both VMax-Vial and nG-Vial (see below). Minimum quantity ≥ 5000 pcs.
Patented VMax-Vial with tamper-evident closure
Patented nG-Vial with tamper-evident closure