“The closure system also provides definitive security feedback,” the company notes, “by producing a 57-decibel ‘snap’ upon closing –– an auditory cue helping consumers recognize still-open medicine bottles.”
The project was not without its share of hurdles. In its early days, Batzel said, “I lost my first mold in a fire, and my adviser passed away shortly thereafter.” So he started over. They 3D-printed models first, using ABS resin. But ABS is typically harder than polypropylene (PP), and some predicted they wouldn’t be able to replicate the “snap” sound using the softer PP resin.
“Pharma also needs virgin material” –– not recycled, he noted. SnapSlide has designed its closure to be material-agnostic, Sordoni said by phone, paving the way for future iterations to consist of various next-generation plastic resins The company has secured eight utility and design patents, and has three more pending. The firm now is working with Miniature Custom Manufacturing LLC, a mid-size, high-volume contract manufacturer in Vicksburg, Mich.
Batzel said that he and Sordoni spoke with a lot of injection molders along their journey –– many of whom said what they wanted to do couldn’t be done. “We considered PP, HDPE and PET,” he said, but I was sure we could get that ‘snap’.” And eventually he did.
They also had to fine-tune such properties as the coefficient of friction and the degree of compression for sliding and sealing. Their initial design was a cube form factor, but “it was too different for the industry,” he said, “and we got a lot of pushback.”
The conservative pharma industry uses PP resin almost exclusively for its closures – especially for the familiar UV-resistant, amber-colored containers – and so it was preferable to stick with a tried-and-true material. An added benefit is that polypropylene is easily injection molded and is highly recyclable.