Polyurethane foam chemistry is used in many applications across industry verticals such as automotive, packaging, construction, electronics, bedding, and furniture. But innovations in foam’s comfort, performance, and safety have been evolutionary at best.
Carbon reports that it can offer an alternative with its elastomer lattice innovations that leverage proprietary programmable resins and software capabilities. With Carbon’s technological capabilities, lattices can successfully displace foam in many applications including headsets, seats, headphones, and orthopedic pads, among others.
Foam’s design constraints
Foam is a versatile and widely used choice for many applications. Foam enables a range of performance characteristics based on factors such as composition, placement, and thickness. Yet, a main limitation of foam in some designs focused on comfort is that the compression force applied to foam increases linearly.
Closed-cell elastomeric foams enable a more non-linear load-compression response, which can deliver products with more comfort. However, the increase in compression performance results in thermal issues that compromise comfort. The closed-cell foams lack breathability and can cause discomfort due to heat from lack of airflow.
Foam, such as expanded Polystyrene (EPS) is often used in safety applications such as helmets and car seats because it can absorb impact energy. But the drawback with EPS designs is the assembly. Multiple foam pieces, each with a different absorption factor, must be assembled into a final part.
A 3D printing solution
Carbon’s technology can produce lattice geometries with functional elastomeric materials. Combined with Carbon software tools, designers can optimize the lattice parameters in their design—such as unit cell type, shape, and strut size—to achieve the desired mechanical response and manufacturability within a part.
Carbon offers a large lattice library where each unique combination of lattice parameters is combined with base materials, resulting in a unique metamaterial with a well understood simulated mechanical response.
Instead of the trial-and-error process associated with conventional lattice prototyping tools, Carbon’s approach requires only the submission of the desired mechanical response for parts and other design constraints, such as weight and size. Using its validated library of metamaterials, the software outputs a lattice structure that meets the mechanical loading requirements of the part and checks for manufacturability. The software enables designers to distribute different mechanical properties within the same part, enabling multiple functional zones.
Carbon’s lattice innovation, in contrast to the insulating closed-cell approach, delivers an open-lattice cell structure with improved airflow and breathability. Comfort can be further improved through a tunable load-compression profile.
The “tunability” offered by Carbon lattices can outperform closed-cell elastomeric foam, delivering a wider stress-strain “band” within the flat plateau region, and better performance on compression response and control.
The Carbon innovation gives designers the ability for digital control throughout the load-compression curve, making it possible to precisely define the transition points between linear elasticity, the plateau, and densification. Such capability will make it easier to develop products for safety applications; enabling the 3D manufacture of a single monolithic part produced from the same material with a design that delivers multiple functional performance zones.
Using Carbon’s technology, engineers can 3D manufacture multiple unique functional zones within the same monolithic part and tune the mechanical properties within each of these functional zones separately.