Otoplastics 3Dresyn OTO-UHF – Ultra-Hard and Flexible Resin

Ultra hard and flexible photopolymer for otoplastics and hearing-related components (UHF system)

Product description

3Dresyn OTO-UHF is an advanced photopolymer engineered for the fabrication of durable ear shells, tips and otoplastic components requiring a balance between rigidity and flexibility.

The material combines high hardness with controlled flexibility, enabling improved comfort, resistance to fracture and long-term durability in demanding audiology applications.

The formulation is based on an Ultra-Hard and Flexible (UHF) architecture, supporting reliable mechanical performance under cyclic loading and thin geometries.

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

Application framework

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.

Typical applications

• Ear shells and hearing aid housings
• Custom ear tips and inserts
• Flexible-rigid otoplastic components
• Wearable in-ear devices requiring comfort and durability

Measured mechanical properties

• Tensile strength: < 40 MPa (ISO 527-1 / ISO 527-2)
• Flexural strength: < 75 MPa (ISO 178)
• Young’s modulus: < 2000 MPa (ISO 527)
• Elongation at break: < 40 % (ISO 527)
• Impact resistance, Notched Izod: < 38 J/m (ISO 180:2023)
• Shore hardness: D78 ± 2 (ISO 868)

Measured physical properties

• Viscosity: < 2000 mPas at 23°C ± 2°C (ISO 3219)
• Density: 1.0-1.2 g/cm³ (ISO 1183)
• Water absorption: < 0.05 % (24 h at 23°C) (ISO 62)

Processing-related characteristics

• Shrinkage: very low (typical)
• Resolution capability: very high (process-dependent)
• Flow and recoating behaviour: optimized for reliable printing performance

Thermal behaviour

• Stable performance under typical operating conditions for otoplastics applications

Physical properties

• Shrinkage: very low (typical)
• Resolution capability: very high (process dependent)
• Dimensional stability: high

Functional performance characteristics

• Combination of rigidity and flexibility for improved comfort
• Enhanced resistance to cracking and fracture
• Suitable for thin-walled and complex geometries
• High durability under repeated mechanical stress
• Stable performance in wearable applications

Printing & processing guidelines

• Printing technologies: SLA, DLP and LCD
• Wavelength range: 385–405 nm
• Compatible with most commercial and professional systems when properly calibrated
• Low viscosity enabling stable recoating and processing
• Very high resolution capability for fine details
• Follow 3Dresyns IFU for exposure, washing and post-curing

Workflow recommendations

• Optimize exposure parameters to balance flexibility and rigidity
• Validate workflow depending on geometry and thickness

Biocompatibility & quality framework

• 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
• Organo-tin free formulation
• Final biological performance depends on validated processing workflow

Testing & processing disclaimer

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.

Regulatory & legal notice

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.

Why choose 3Dresyn® OTO-UHF

• Balanced ultra-hard and flexible behavior
• Improved comfort and durability in wearable devices
• High dimensional stability and low shrinkage
• Very high resolution capability
• Compatible with SLA/DLP/LCD systems
• Organo-tin free formulation

Document reference: TDS-OTO-UHF-EN | Version: 1.0 | Last updated: March 2026