It's not generally known, but Gillette was one of the earliest consumer products companies to use 3D printing technology.

Since the late 90's, Gillette has brought the additive manufacturing toolbox into use to prototype a wide range of shaving products. While back then 3D printing was incapable of prototyping functional razor cartridges – it seems they tended to deform once they were exposed to hot water – the company has a long history of using 3D printed prototyping for the bodies of their line of razors.

Now in addition to using AM to development razors in a design sense, a new patent filed by the company indicates that Gillette found a solution to the razor cartridge problem.

Back in 1997, Robert Brown, the director of external technology for the Gillette Co., was instrumental in his company's introduction of rapid prototyping to quickly generate prototypes for eventual use in tooling.

"A technology can be successfully implemented, but whether it has a direct impact on the company's financial results is another matter," Brown said at the time. "It was a means of drawing in the people that would benefit from RP and to solicit their ideas about how it should be used."

Through a program of seeking feedback from company staff, Brown managed to figure out how using rapid prototyping and AM could indeed impact the bottom line at Gillette and shorten new product lead times.

"We were able to establish a strategy for RP based on the input of designers and engineers within a year," Brown said. "It quickly became apparent that our technical people wanted functional, high-accuracy models with which they could measure properties, study assembly, and estimate production costs."

In that patent filing, Gillette reveals they intend to use photopolymerization to prototype those cartridges. The patent application indicates DLP is used in the current invention, but the preferred embodiment would employ stereolithography (the difference being whether the liquid resin is cured with a laser or DLP projector).

It's thought that increasing the temperature resistance of the cartridges will require a filler material like aluminum oxide, crystalline silica or perhaps a ceramic material.

The filler material would be suspended within the resin, and the company says it will be an aluminum oxide nanoparticle formulation.

Direct metal laser sintering is also mentioned as an option to create the razor's metal inserts.

"In a preferred embodiment, the metal insert is formed by direct metal laser sintering (DMLS), a form of rapid prototyping. Forming a metal insert by the above described process provides a time efficient way of preparing different inserts with varied angles, positioning of slots and overall size, without suffering a reduction in quality. Once the metal insert has been formed, blade assemblies are loaded into slots of the metal insert before the metal insert is placed in the housing."

Gillette has no plan to begin using the technology for production, but they say "rapid prototyping provides a quicker, more efficient means to experiment with different forms of a product before committing to the cost of making molds for mass production. In a field such as razor cartridges where small changes can make a significant difference to performance of a razor cartridge, having this flexibility in a functional razor cartridge is very valuable."