Processing Liqcreate Bio-Med Flex – biocompatible flexible 3D-printing resin

Correct exposure is essential for Bio‑Med Flex because it directly determines surface quality, dimensional accuracy, mechanical performance and the ability of the material to meet biocompatibility requirements. Insufficient curing leads to tacky surfaces and weak geometry, while excessive curing can distort dimensions and reduce flexibility, meaning that only a well‑balanced exposure setting preserves the intended mechanical behavior and ensures the part cures cleanly and safely for medical use.

Flexible materials place far more stress on the support structure than rigid resins, because the part flexes slightly during every peel cycle and transfers that movement directly into the supports. This means Bio‑Med Flex requires supports that are not only stronger, but also more stable and better anchored than those used for stiff materials. A reliable strategy includes enlarging the contact diameter, thickening the support beams and adding extra supports beneath wide overhangs or large cross‑sections, ensuring the part remains completely stable throughout the print:

Flexible parts naturally deform slightly during the peeling step, and if the support structure is not strong enough to stabilize the model, this movement can lead to visible layer shifts, bending of thin sections, premature detachment from the supports and ultimately a failed print.

To achieve reliable biocompatibility and the correct mechanical behavior, Bio‑Med Flex must be processed through a validated workflow that controls every stage of printing, washing, drying and post‑curing. Each step in this workflow ensures that the resin cures completely, remains free of oxygen‑inhibited surfaces and reaches the performance and safety levels required for medical use.

Bio‑Med Flex has been validated according to ISO 10993‑5:2009, ISO 10993‑10:2021 and ISO 10993‑23:2021, meaning it meets cytotoxicity, sensitization and irritation requirements when processed through the advised workflow. These results only apply when the complete validated procedure is followed, and users producing regulated medical devices remain fully responsible for compliance, documentation and registration.

Bio‑Med Flex parts can be disinfected with standard medical disinfectants and safely sterilized in an autoclave, using validated steam‑sterilization programs at 121°C (250°F) or 134°C (273°F). To maintain both biocompatibility and sterilization compatibility, the parts must be fully and correctly post‑cured before undergoing any steam‑sterilization cycle.

After a failed print, the resin should be filtered to remove any cured particles, using a standard resin filter and only clean, dry, uncontaminated tools or containers to prevent introducing impurities. For best results, perform the filtration when the resin is at 25°C (77°F), as the viscosity and flow characteristics at this temperature help ensure that all debris is effectively removed without affecting material performance.

Bio‑Med Flex can produce detailed features, but the flexible nature of the material means that large thin surfaces are more likely to deform or fail during printing and post‑processing. As a general guideline, a minimum wall thickness of 2 mm is recommended for broader areas, while thinner local features can be printed successfully when they are supported adequately. Larger thin walls benefit from additional reinforcement to prevent warping, and increasing the thickness to 5–10 mm provides noticeably greater stability and reduces the appearance of layer lines.

Flexible materials behave very differently during the peeling phase because the part flexes and shifts slightly with every lift, which means orientation becomes a critical factor in achieving a stable and accurate print. By positioning the model at a controlled angle and avoiding broad flat surfaces parallel to the build plate, you reduce the amount of stress transferred into the supports and minimize deformation, leading to cleaner layer formation and a significantly higher success rate with Bio‑Med Flex:

Correctly printed Bio‑Med Flex parts show a clean and uniform surface appearance, with clearly defined pixel lines and a consistent matte finish after washing and drying, indicating that the exposure settings, support stability and peeling behavior were all properly controlled during the print:

Bio‑Med Flex exhibits moderate shrinkage comparable to other flexible resins, so dimensional accuracy depends on applying the right compensation strategy. Standard Chitubox compensation works well for parts up to roughly thirty millimeters, while larger components may require slightly increased values to maintain their intended dimensions. Very small parts can become oversized if compensation is set too high, which is why critical applications benefit from printing a small test block first to verify the correct settings before producing the final part.

Bio‑Med Flex can fail for several reasons, most of which relate to the material’s sensitivity to movement, temperature and exposure. Typical causes include support tips that are too small to stabilize the part, overhangs that are too wide for flexible geometries, wall sections that are too thin to withstand peeling forces, resin that is printed below the recommended temperature range and exposure settings that leave surfaces under‑cured. These factors increase deformation during peeling and reduce layer adhesion, making print instability more likely:

Store Bio‑Med Flex in its original sealed bottle at a stable temperature between 5 and 30°C (41–86°F), keeping it protected from sunlight, heat sources, static electricity and any contact with food. Proper storage preserves the resin’s stability, maintains its biocompatibility and ensures consistent printing performance over time.