Nylon-Like Resin "Tus" for Functional Snap-Fit Enclosures

Challenge

A consumer electronics startup was developing a ruggedized wearable device and required a durable, snap-fit enclosure cap (as shown in the image). The design featured complex undercuts and living hinges that demanded high flexibility and fatigue resistance. Traditional injection molding required expensive steel tooling ($30,000+) which was unjustifiable for the initial pilot run of 200 units. Standard rigid resins were too brittle and cracked during assembly, while flexible rubbers lacked the structural rigidity needed to protect internal components.

Solution

The engineering team selected Nylon-Like Resin "Tus" processed via High-Resolution Stereolithography (SLA). This material was specifically chosen for its balanced mechanical properties, mimicking the toughness and semi-flexibility of injection-molded Nylon (PA12). The "Tus" resin allowed for the direct printing of functional snap-fit tabs and intricate gear-like textures without support structure interference. Its low viscosity ensured precise replication of the fine details on the cap's surface, while its elongation at break (>40%) prevented fracture during the repetitive snap-on/snap-off testing cycles.

Results

· Functional Durability: The Tus resin caps withstood over 500 assembly/disassembly cycles without hinge failure or tab breakage, matching the performance of final-production nylon parts.

· Tooling-Free Agility: Eliminated the 8-week lead time for mold fabrication, delivering 200 fully functional, matte-black enclosure caps in just 5 days.

· Cost Efficiency: Reduced the per-part cost by 85% compared to soft tooling, enabling extensive field testing and user feedback collection before committing to mass production molds.