Glass: A new generation of screw rings for perfume bottles

As consumers expect brands to help them live more sustainable lifestyles, the need for environmentally and climate-friendly packaging is becoming increasingly important in all sectors. For perfumes bottles, this often means choosing solutions allowing them to be refilled or, at least, to easily separate the different parts and thus facilitate their recycling at the end of their life. But this change is not without important industrial, technical and aesthetic constraints!

The interchangeability issue

Replacing the traditional crimped finishes (known as FEA finishes) with screw finishes that allow the sprayer to be disassembled and reassembled, calls for the development of glass vials with suitable necks and compatible accessories (pumps, neck covers). At the same time, perfume brands want to stick to the aesthetic codes of existing bottles, with smaller pumps. Not to mention the fact that some markets, such as Saudi Arabia, which are often large perfume consumers, also require products to be sold with non-removable pumps. The challenge is therefore to promote the interchangeability of the FEA finish/screw finish.

To this end, stakeholders in the sector (glassmakers, pump manufacturers, brands) have joined the Cetie [1] in a Working Group known as the "Flaconnage Geometry Group" [2] to develop new standards for interchangeable rings. Cetie’s objective was to offer screw rings with the lowest possible height, allowing perfumers to use the same pump covers as their crimped counterparts while guaranteeing the consumer optimum unscrewing and screwing comfort.

"The creation of a Cetie standard allows avoiding the multiplication of incompatible technical solutions, patented separately by each player, by creating instead a harmonised solution, technically validated by professionals, and usable by all," explains Josquin Peyceré, Cetie’s Secretary-General.

In this case, the difficulty was 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 perfumer’s choice

To offer maximum flexibility to fragrance houses, two standards have been produced and released in early May 2021 [3]. If the brand wishes to have 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 crimp finish with a counter-bead created for the purpose [4]. 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. "This solution is very convenient for creating a new item with a reduced investment for both types of rings," explains the Cetie.

If, instead, the priority of the brand is to preserve the existing components by respecting the original design (in particular the very low finish of the FEA version), it will then opt for a screw ring with no counter-bead, which allows this finish to be barely 1.5 mm higher than the crimped version. This option is not suited for very heavy vials (> 200/250g) and is just wide enough for the pumps (through bore guaranteed at 7.8 mm, for pump bodies at 7.7).

These solutions have been studied using the 15 mm FEA finish, which represents 65% of the crimp finish market. They are also available in other dimensions, mainly Ø13 and Ø18, then possibly Ø17 and Ø20 according to the needs expressed.

Stoelzle designs a new cubic bottle with a short screw ring

Aligning to this new standard, Stoelzle Masnières Parfumerie has developed a new standard 100ml cubic bottle. Following the new Cetie standard, this bottle can be made either with the new screw ring, which allows all the elements to be separated for recycling or with a traditional crimp ring. The design and aesthetics of the bottle remain unchanged, only the neck is changed, using a specific mould at the time of production.

"This new offer allows each customer the possibility to choose between the FEA or Screw neck finish depending on the brand strategy, the project and the adaptation time of their packaging lines," explains Stoelzle in a release.

According to Stoelzle officials, many technical tests have been carried out on customer lines, which have led to the approval of the solution by many leading brands.