Otoplastics 3Dresyn OTO-HF – Hard & Flexible Resin (Shore D70)

3Dresyn OTO-HF is an advanced photopolymer engineered for the fabrication of clear, durable and hard-flexible ear molds and otoplastic components.

The material provides a unique balance between flexibility and rigidity, enabling comfortable yet mechanically resistant components with excellent optical clarity.

The formulation delivers high impact resistance and stable performance under repeated deformation, making it suitable for wearable audiology applications.

It is compatible with a wide range of SLA, DLP and LCD systems used in professional audiology and dental laboratories.

Intended for professional use in vat photopolymerization (SLA, DLP and LCD) additive manufacturing for audiology and otoplastics workflows.

Final suitability of printed parts must be validated by the user according to the specific application, processing conditions and applicable regulatory requirements.

• Transparent ear molds and earmolds
• Custom ear shells and hearing aid housings
• Flexible-rigid in-ear components
• Wearable devices requiring clarity, comfort and durability

• Tensile strength: <20 MPa (ISO 527-1 / ISO 527-2)
• Flexural strength: <20 MPa (ISO 178)
• Young’s modulus: <500 MPa (ISO 527)
• Elongation at break: <40% (ISO 527)
• Impact resistance (Notched Izod): <85 J/m (ISO 180)
• Shore hardness: D70 (ISO 868)

• Density: 0.90–1.20 g/cm³, depending on formulation and, where applicable, selected version (ISO 1675)
• Water absorption: ultra-low (ULWA, hydrophobic) (ISO 62)
• Printing shrinkage: no measurable dimensional shrinkage after calibration under validated processing conditions
• Resolution capability: very high (features below 20 µm depending on process)
• Dimensional stability: high
• Viscosity: optimized within the processing range required for the intended printing process and application
• Structure: isotropic (minimizes light scattering and diffraction)

• Stable performance under typical wearable conditions

• Optical behaviour: water-clear, high transparency, non-yellowing
• Excellent optical clarity and non-yellowing

• Balanced hard-flexible behavior for comfort and durability
• High optical clarity for transparent components
• Excellent impact resistance and crack resistance
• Hydrophobic behavior with very low water absorption
• Suitable for thin-walled and complex geometries

This material contains reactive components that may cause skin and eye irritation prior to full polymerization. Printed otoplastic components must undergo validated cleaning and post-curing workflows to ensure maximum achievable polymer conversion and reduction of residual extractables, leachables and byproducts. Final device qualification and regulatory compliance remain the responsibility of the legal manufacturer.

• Printing technologies: SLA, DLP and LCD
• Wavelength range: 385–405 nm
• Compatible with most commercial and professional systems when properly calibrated
• Optimized for high-resolution transparent parts
• Follow 3Dresyns IFU for exposure, washing and post-curing

• Use validated cleaning and post-curing workflows to preserve optical clarity
• Optimize parameters to minimize haze and maximize transparency

• Biocompatibility-related testing may be performed under controlled laboratory conditions
• Evaluation frameworks may include ISO 10993 methodologies
• Manufacturing aligned with ISO 13485 quality management systems
• Final biological performance depends on validated processing workflow

Material properties are measured on printed and post-processed specimens and may vary depending on printer type, printing parameters, build orientation, post-curing conditions and workflow validation. Reported values are indicative and provided for reference only.

• Hard-flexible balance for comfort and durability
• High impact resistance and dimensional stability
• Very low water absorption (ULWA)
• Very high resolution and low shrinkage
• Compatible with SLA/DLP/LCD systems

This material is supplied as a professional manufacturing material for audiology and otoplastics workflows and is not marketed as a finished medical device. The regulatory classification, conformity assessment and validation of any final device manufactured using this material remain the sole responsibility of the legal manufacturer in accordance with applicable regulations.

This technical datasheet should be used together with the relevant processing, calibration, safety and workflow documentation available in the 3Dresyns® Resources section.

Access the 3Dresyns® Technical Resources (IFU, calibration, CRT, post-processing and troubleshooting)