The most difficult issue is to maintain the diameter of the casing, as the 1 mm thick plastic screw-threaded ring reduces the diameter of the glass finish by the same amount, as the glass finish always has to allow the 7.7 mm diameter pump to pass through. The professionals of the sector (Perfumers, pump and bottle manufacturers) have therefore come together at Cetie to design the new screw finish that meets these criteria. This one is based on :
The external diameter and thread profile of the GPI 415,
But with a reduced thread length (1.25 turns) to minimise overall height
With a sealing ring on the top of the finish, and self-unscrewing 'rice grains' on the thread.
From there on, the perfumer is offered two options:
- Either he wants to keep the possibility of producing both formats (crimp finish and screw finish) on a given model of bottle. In this case, the most interchangeable version is equipped with a counter-bead, and it corresponds to a crimped finish with a counter-bead created for the occasion. The alignment of the heights of the two rings and the diameters under the ring allow the glassmaker to use a single set of moulds for the body of the bottle, on which he adapts either a screw ring mould or a crimp ring mould. The investment is therefore reduced, and flexibility is optimised.
- Either the perfumer seeks above all to preserve the existing components and to respect the original design (in particular the very low finish of the FEA version). Then he will opt for a screw ring without counter-bead, which allows this finish to be barely 1.5 mm higher than the crimped version.
This option does not allow very heavy vials (above 200/250g) and is just wide enough for the pumps (through bore guaranteed at 7.8 mm, for pump bodies at 7.7).
Other options were studied by the members of the Cetie group, which did not meet the needs of the perfumers as well. The different choices defined on these finishes (thread profile, rice grain geometry, etc.) are currently being tested to check that the expected functions and technical characteristics are indeed there.
This study was carried out on the basis of the 15 mm FEA finish , which represents 65% of the crimp finish market. It will then be declined on the other dimensions, mainly Ø13 and Ø18, then possibly Ø17 and Ø20 according to the needs expressed. The three families of rings thus created will become Cetie standards available to professionals in the sector as soon as they are created:
- Interchangeable Screw Finish with counter-bead
- Interchangeable Crimp Finish with counter-bead
- Screw Finish without counter-bead
All the stakeholders of the interprofessional can join Cetie's working groups.
All you need to do is make a request on firstname.lastname@example.org
More info? Download the presentation of this work below.