1. Client Background
Mosteb was approached by our client, a lifestyle brand specializing in home fragrance, to develop a custom 150ml diffuser bottle for their new aromatherapy line. The brand’s concept was to have a neat, moderately-sized bottle that would combine an attractive visual look with a functional usage—sufficiently small to be able to easily be placed on a desk or nightstand and yet, large enough for an extended use. The reason they put their trust in Mosteb was our well-established proficiency in diffuser packaging and our capability to provide not only the exactness in design but also the quality of large-scale production that is stable.
2. Challenge
Though the 150ml diffuser bottle may look like a straightforward thing, the technical problems were definitely not simple. The bottle needed to work with different caps and reed holders, so the threading of the neck had to be very precise and the tolerance control tight in order to assure a sealing without leaks. Also, as the 150ml size is a kind of a middle volume between small and large mold categories, it became very hard to make the production batches consistent. Even if there were slight changes in mold cooling rates, it could lead to dimensional changes which would have an impact both on the sealing performance and on the visual uniformity – these being the most important aspects for a premium fragrance brand.
3. Cause Analysis
After multiple tests, our technical team came up with the following main problems:
- The temperature of the mold was not evenly distributed which resulted to very small changes of the neck diameter and the height of the bottle.
- Deformation of the thread during the annealing process, where local areas of the temperature/time profile resulted in the instability of the seal due to the slight sealing layer.
In order to eliminate the problems, we worked hand in hand with the client’s quality control team checking the bottle-to-cap fit, air-tightness data, and aesthetic uniformity to be sure that every bottle was up to their luxury standard.
150ml Aroma Diffuser Empty Glass Bottle with Vertical Stripes
150ml Empty Reed Diffuser Glassware with Retro Relief
4. Solution
To work out the difficulties, we took the following steps:
- We narrowed down the mold temperature control by setting up separate thermal regulation zones to keep the glass viscosity at a stable level during the forming process.
- We improved thread accuracy by performing high-tolerance CNC polishing of the mold cavity and by raising the measurement frequency during production.
- We confirmed batch uniformity by installing in-line dimensional scanning and automated rejection for units that are off-spec.
- We created tailored cooling profiles through the use of simulations to equalize shrinkage between the body and the neck.
5. Result
After three rounds of sampling and fine-tuning, the final batch achieved a 99.8% consistency rate in neck dimension accuracy and passed all sealing tests under various temperature conditions. The client praised the result as a perfect blend of form and function, leading to a long-term partnership with Mosteb for their entire diffuser bottle series.
