Instructions for Use (IFU) for Otoplastics and hearing-device workflows
This document provides application-specific instructions for otoplastics, audiology and hearing-device manufacturing workflows using 3Dresyns® photopolymer resin systems.
This IFU must be used in conjunction with:
- Instructions for Use (IFU)
- Any relevant printer-specific IFU
- Any relevant application-specific IFU where applicable
This document does not replace the general IFU and applies only to workflows targeting custom-fit ear-related components, audiology parts and otoplastics manufacturing.
Scope of application
This IFU applies to:
- Patient-fit otoplastics components
- Audiology workflows requiring accurate fit and repeatable processing
- Ear-related parts where surface quality, comfort and dimensional control are critical
- SLA, DLP and LCD vat photopolymerization systems unless otherwise specified for a given material
This IFU does not replace:
- Device-specific regulatory evaluation
- Clinical validation
- Risk management obligations of the legal manufacturer
- Material-specific TDS, CRT or printer qualification workflows
Nature of otoplastics workflows
Otoplastics manufacturing is fit-sensitive, geometry-sensitive and process-dependent. Final performance depends on the full material–printer–process–post-processing chain, including:
- Resin formulation and version
- Printer technology and optical behavior
- Build orientation and support design
- Layer thickness and exposure strategy
- Cleaning, drying and post-curing conditions
- Final fit verification and workflow validation
Small variations in processing may affect fit accuracy, surface feel, flexibility, rigidity, comfort and repeatability.
Workflow objectives
Otoplastics workflows typically require controlled balance between:
- Fit accuracy for patient-specific geometries
- Smooth surface quality
- Mechanical behavior matched to the intended part function
- Reliable post-processing and finishing
- Repeatable dimensional stability across batches
Printer and build considerations
- Use validated printer configurations and stable optical systems.
- Use layer thickness and exposure settings that prioritize fit fidelity and surface quality.
- Orient parts to reduce visible support marks and minimize support contact on critical fit surfaces.
- Do not change support strategy, exposure settings or orientation for production without re-verifying fit and dimensional behavior.
- Use structured calibration before production when high fit precision is required.
Cleaning and post-processing considerations
- Cleaning must remove uncured surface resin without damaging fine ear-related geometries.
- Excessive washing, aggressive solvent handling or uncontrolled thermal exposure may alter fit, softness, surface feel or mechanical response.
- Post-curing must follow validated material- and printer-specific conditions.
- Parts must be fully dry before final post-curing unless a validated alternative workflow is explicitly defined.
Surface quality and comfort considerations
- Surface roughness, support scars and excessive stair-stepping may negatively affect comfort and fit.
- Critical fit zones should be protected from unnecessary support placement.
- Final workflow validation should include visual inspection and functional assessment of comfort-relevant surfaces.
Mechanical behavior selection
Material selection must be matched to the intended otoplastics function:
- Rigid grades for shells and structurally stable components
- Tough grades for durable housings and repeated handling
- Flexible or soft grades where comfort and compliant contact are required
Mechanical suitability must always be validated in the final workflow.
Quality control and validation
- Verify dimensional accuracy using reference geometries and routine calibration checks.
- Confirm repeatability across lots, builds and post-processing cycles.
- Validate final workflow under intended fit, comfort and application conditions.
- Where applicable, the legal manufacturer remains responsible for final regulatory classification and device compliance.
Interpretation principle
3Dresyns® otoplastics materials must be understood as professional manufacturing materials for additive manufacturing workflows. Final suitability for patient-fit, hearing-related or other ear-related applications depends on controlled implementation, appropriate validation and application-specific responsibility of the user.