Thermoforming, including vacuum-forming, plays a significant role in a diverse workshop environment, and Mayku, the creators of desktop thermoforming machines, offer valuable insights for achieving optimal outcomes when crafting molds with filament-based 3D printers.
When a mold comes into direct, extended contact with a heated sheet of partially molten plastic, it’s crucial to consider its durability for repeated use. Fortunately, adhering to a set of straightforward guidelines can yield exceptional results. Here are the key recommendations:
- Prioritize Smoother Vertical Surfaces: To facilitate demolding, maintain layer heights between 0.1 mm and 0.2 mm. Thermoforming essentially molds plastic like a second skin onto and into the mold, making smoother surfaces highly advantageous.
- Implement Generous Draft Angles: Aim for a draft angle of 5 degrees. While injection molding typically employs draft angles of 1-2 degrees, a more pronounced angle is necessary due to the inherent surface roughness of FDM prints caused by layer lines.
- Reinforce Perimeters and Top Layers: Given that the mold’s exterior endures the most prolonged exposure to heat, Mayku recommends wall and top layer thicknesses between 3 mm and 5 mm. Don’t overlook the inclusion of vent holes to aid in the thermoforming process.
- Opt for High Infill for Enhanced Strength: Molds must withstand mechanical stress and heat, so target a 50% or higher infill percentage to produce a resilient part that resists deformation.
- Verify Printer Capability: When 3D printing substantial components with a high infill, be cautious of potential lifting or warping during the printing process. Employ enclosures or draft shields as necessary, depending on your specific printer and material.
- Choose the Right Material for the Mold: For production molds subject to thermoforming’s heat and stress, Mayku recommends using nylon, known for its resilience. However, other materials are suitable for prototyping. For instance, PLA molds, though susceptible to deformation under thermoforming heat, can serve well for at least one molding operation.
Thermoforming opens up new possibilities for innovative hackers, and 3D printing molds complements this technique admirably. While small “dental” formers are readily available from various discount overseas retailers for crafting small parts, thermoforming also shines in costume and prop creation. For those seeking unconventional applications, consider experimenting with custom-shaped mirrors by thermoforming laminated polystyrene—a unique and creative venture.
Wanting to try these techniques out? We have a range of 3D printers here: