There are countless applications for products and parts made with 3D printed molds, such as prosthetic aligners, micro needles and organs on a chip, and even building restoration. Experimental design studio Slicelab, remotely based in Denver and New York, specializes in digital manufacturing and offers architectural design and product / furniture design services. Founded in 2012 by Arthur Azoulai and Diego Taccioli, the studio says it operates “between the disciplines of art and architecture,” and recently investigated the use of 3D printing in the making of molds for complex shapes. of concrete. This work resulted in a truly charming piece of furniture called the Delicate density table.

Slicelab was drawn to 3D printing for this project because the technology has fewer limitations in terms of cost and time to design and create complex shapes.

“A concrete exploration using 3D printed molds with the goal of seeing how delicate, detailed and finished concrete can become while being structurally rigid,” the studio wrote. “Using 3D printing as a new way to make concrete thanks to its ability to make molds, we became interested in pushing the natural limitation of concretes through fine geometries.”

Concrete exhibits very high compressive strength, but it is more brittle when used to create shapes with fine geometries that create a lot of tensile loads. Additionally, the material also has the unique ability to take any shape, while 3D printing has the ability to create complex geometries, and Slicelab saw the potential to combine the two to create a piece of furniture that had to. both material density and delicate shape, while retaining the strength of concrete. The studio has partnered with Concrete work and Hummingbird 3D for this project, which resulted in several unique molds which were then assembled and used to make an 86 kg white concrete table with dimensions of 152.5 x 45.5 x 38 cm.

The studio understood the overall structure of the model in advance, through the use of digital simulation and optimization. It was then that they realized that due to the size of the table design and the build volume constraints of the LulzBot TAZ 3D printers that they would be using, they would have to split the model into 23 separate rooms.

Each of the 23 parts has been oriented and optimized in a certain order so that the least amount of supports should be used which would help speed up assembly. The parts were 3D printed from recycled PLA, then clamped together to form a single 5-foot investment mold, which weighed approximately 66 pounds and could support less than 200 pounds of unreinforced super high performance concrete.

“The order in which the parts were put together played an important role in how the parts were put together,” Slicelab explained. “Even with absolute printing precision, plastic can crack, warp and often create uneven surfaces that require a lot of post-processing work to fully function as a sealed mold for concrete, especially when placed. on a vibrating surface. “

The team created the mold with a built-in, leveled diamond platform on top, so that it could be positioned upside down and flat when concrete was poured inside, to fit. ensure that most of the air bubbles would be at the bottom of the table and not be visible. from the top. This reinforcement platform also helped keep the center of gravity low during pouring, and was also designed to be the only freed part of the concrete in one piece. Speaking of pouring concrete, the voids at the bottom of the mold were used to pour concrete into three main access points, through the ten feet, and into the main cavity of the bench.

Once the concrete had completely hardened inside, the mold was literally broken piece by piece to reveal the final picture of delicate density. Slicelab then used diamond pad wet sanding to achieve a mirror finish, which also really emphasized the fluid shape of the table top – a major contrast to the porous texture on the table legs.

Since we’re all focused on sustainability here in the AM industry, it’s great to know that the team also recorded as many broken pieces of the mold as possible, so they can be used on a date. later for a different project.

(Source / Images: Slicelab)