Photocentric Innovator in Photopolymer, 3D Printing

3D Printing Perfume Lids

A Study in Producing Complex Geometries in Mass Production Quantities with the LC Magna

Executive summary

A set of 20 different perfume lids were designed using the freedom of geometry that only 3D printing allows. These were all printed on a Liquid Crystal Magna flat to the platform, so no supports were required. Different print settings were run to determine the optimal process times. Then a production run of a few thousand caps were made, to enable accurate costings to be ascertained, and the total cost per part was calculated. This design shown allowed 104 caps to be fitted onto the Magna slotted platform, and at 100-micron layers it took 2 ¼ hours to print a platform of them. The farm of 45 printers could produce 12,000 a day at a cost of €0.39 each.

The benefits to the luxury packaging industry

Luxury packaging has to stand out- what better way is there than by showing off a manufacturing method that looks markedly different to every other product the purchaser has ever seen. The eye-catching ability that only 3D Printing has, to create lattice structures that are beautiful, elegant, and structurally resilient, makes this an unused asset in luxury packaging. Up until now, the cost per part has been prohibitively expensive, even for this industry, but now with control of the manufactured material costs and the use of large format LCD printers, this is no longer the case. Here we have created functional, low-cost, mass-produced caps that the consumer has never seen before, making this packaging both exceptional and cost-effective

The additive designing process

The geometries that injection moulding can produce are severely limited in complexity, in contrast 3D Printing has unlimited freedom. In addition, complex multi-impression moulds are expensive and slow to produce and require iterative improvements before full scale manufacture is possible 6 months later.

A geometric structure based on the Photocentric drop logo was used as the inspiration for the design. A generic perfume lid cavity at the centre was made and kept consistent in size throughout testing.

All designs were self-supporting, thus eliminating the need for post-processing beyond thermal shocking off the platform.

Figure 2. The baseline geometry used for all the perfume lids, and its cross-section (right)

The caps were arranged on the platform in different configurations using Photocentric Studio software

We used the baseline geometry, applied a Subsurface Modifier to increase the density of the mesh by increasing the resolution of the model, splitting the quads that make it. We then applied a Wireframe Modifier to convert all edges into beams, connected at the vertices. The thickness of these beams could be adjusted freely. Due to the wireframe modifier the surface area of the base is significantly reduced. A custom base was made to ensure adhesion to the build-plate, and the two are combined with a Boolean Modifier. We then exported the geometry as an STL and import into Photocentric Studio.

Unique designs for each cap are now possible at no added cost

Many geometries were tested, some designs were identically replicated across the build platform, but by implementing an algorithm to change each design slightly, each cap could be made as individual as the buyer’s DNA by a computer algorithm- to be printed with no implications to productivity or extra part cost.

The printing process

Photocentric developed the LC Magna and it has become a revolutionary large-scale 3D printer designed for mass manufacture. LCD printing technology allows hundreds of geometries to be produced simultaneously, rather than voxel by voxel. At 100 micron layers these layers are hardly noticeable, but by using software we could smooth the exterior surface completely and the cap appeared identical to an injection moulded version.

The full production process was established in the print farm with 45 magna printers. Platforms were washed in the Photocentric Air Wash L filled with Photocentric Resin Cleaner, an environmentally friendly wash solution, and dried and then placed on the Photocentric Conveyor Cure L to emerge 30 seconds later after being fully cured in high intensity UV light.