Instructions for Use (IFU) for Vat Photopolymerization (SLA, DLP & LCD)

These Instructions for Use (IFU) define the general processing principles, calibration methodologies and user responsibilities associated with the use of 3Dresyns® photopolymer resin systems processed by vat photopolymerization technologies, including laser-based SLA and projection-based DLP & LCD systems.

Final part performance, safety and application suitability depend on strict adherence to qualified workflows. Deviation from these instructions may significantly affect mechanical behavior, surface quality, functional performance and long-term stability.

Scope of application

This IFU applies to photopolymer resin systems processed by vat photopolymerization technologies.

These instructions describe general methodologies and reference workflows and do not replace material-specific documentation, printer-specific IFU supplements or application-specific validation required by the user.

Material system and version control

3Dresyns® photopolymer resins are supplied as system-based materials that may exist in multiple formulation versions, viscosities, colors and functional configurations.

Users must verify that the selected resin version, lot number and associated documentation correspond to the intended printer technology and application. Mixing versions or modifying formulations outside qualified workflows may invalidate expected performance.

Printer compatibility and exposure technologies

Vat photopolymerization includes different exposure architectures that require technology-specific workflows.

Laser-based SLA systems rely on localized beam scanning.
Projection-based systems (DLP & LCD) expose entire layers simultaneously.

Workflows, exposure strategies and fine-tuning approaches must not be transferred between these architectures without re-evaluation.

Laser-based SLA systems

Laser-based SLA systems use focused beam exposure and scanning strategies that influence curing depth, resolution, anisotropy and surface finish.

Typical reference parameters include:

• Z layer thickness: typically 50–100 microns (lower or higher values may be printable depending on formulation and exposure strategy)

These values represent starting points only and must be validated for each resin system, printer and application.

Fine-tuning additives for laser-based SLA systems

Fine-tuning additives may be used to adjust printing speed and resolution on laser-based architectures only.

Fine Tuner FT1 (speed optimization):
Typical dosing increments: 0.1%

Fine Tuner LB1 Bio (resolution optimization):
Typical dosing increments: 0.3%
Ultra-low water absorption version available: LB1 Bio ULWA

Due to localized energy delivery, small formulation changes may produce significant effects. Fine-tuning steps must be introduced incrementally and validated.

Projection-based systems (DLP & LCD)

Projection-based systems expose larger resin volumes per layer and require different exposure strategies compared to laser-based systems.

Typical reference parameters depend on system design and application and include:

• layer thickness

• exposure time per layer

• light intensity and wavelength

• build orientation and support strategy

Projection-based workflows must be validated independently from laser-based workflows.

Fine-tuning additives for projection-based systems (DLP & LCD)

Fine-tuning additives may be used to adjust speed and resolution on projection-based systems.

Fine Tuner FT1 (speed optimization):
Typical dosing increments: 0.5–1.0%

Fine Tuner LB1 Bio (resolution optimization):
Typical dosing increments: 1.0%

Higher incremental dosing is typically required due to differences in exposure volume and energy distribution.

Determination of optimum exposure time (curing rate methodology)

The determination of appropriate exposure time is a critical step in vat photopolymerization workflows. Exposure time directly influences curing depth, green strength, adhesion, resolution and dimensional accuracy.

Because curing behavior depends on resin formulation, printer technology, exposure mechanism and process conditions, exposure time must be determined experimentally for each workflow.

Curing rate table concept

A curing rate table establishes the relationship between exposure time and cured thickness for a given resin system under defined conditions.

The table is generated by curing resin samples at increasing exposure times and measuring the resulting cured thickness and qualitative green strength.

Values shown in example tables are illustrative only and must not be used as universal settings.

Example curing rate table (user-generated)

The table below illustrates the structure of a curing rate table used to correlate exposure time with cured thickness and qualitative green strength.

The values shown are examples only. Users must generate their own curing rate table under their specific printer, resin and workflow conditions.

Calibration procedure (spot timer method)

Step 1: Remove the build platform from the printer.
Step 2: Place a small resin drop on a clean glass slide.
Step 3: Position the glass slide at the center of the vat or tank.
Step 4: Expose the resin drop for a selected exposure time.
Step 5: Remove uncured resin and measure cured thickness using a caliper or micrometer.
Step 6: Record cured thickness and qualitative green strength.
Step 7: Repeat the procedure at increasing exposure times.

This procedure generates a curing rate curve specific to the resin, printer and exposure configuration.

Interpretation of curing behavior

Typical qualitative observations may include:

• uncured or weakly cured material at short exposure times

• increasing cured thickness and strength with increasing exposure

• overcuring at excessive exposure times, leading to brittleness or loss of detail

The optimal exposure time corresponds to the desired balance between curing depth, adhesion and resolution.

Selection of starting print exposure settings

As a general methodology:

• select an exposure time corresponding to approximately 1.5 cured layers as an initial reference

• reduce exposure toward 1.1–1.2 layers to increase speed and resolution

• increase exposure toward 1.75–2.0 layers to improve robustness if failures occur

Bottom or burn-in layers should be selected based on the exposure time that produces the strongest adhesion under the same conditions.

Validation using reference test geometries

3DTest1 (flat geometry without supports)
Confirms basic printability and provides an indication of XY resolution.

If failure occurs:

• full detachment: increase burn-in exposure and/or number of bottom layers

• soft or tender parts: increase standard exposure

• brittle parts or excessive adhesion: reduce exposure

3DTest2 (flat geometry with supports)
Validates supported printing and enables evaluation of XYZ dimensional accuracy.

Z accuracy may be calculated as:
Z error (%) = (measured − theoretical) / theoretical × 100

Fine adjustment and optimization

If additional resolution, accuracy or performance is required, exposure parameters may be further adjusted and, where applicable, fine-tuning additives may be introduced according to the relevant sections of this IFU.

All adjustments must be introduced incrementally, documented and validated.

Post-processing requirements

Post-processing is an essential component of vat photopolymerization workflows.

Printed parts must undergo appropriate washing, drying and post-curing steps defined for the selected resin system and application.

Deviation from qualified post-processing workflows may significantly alter surface chemistry, mechanical performance and long-term stability.

Handling, storage and contamination control

Resins and printed parts must be handled using appropriate protective equipment and contamination control measures.

Materials should be stored under controlled temperature, light exposure and humidity conditions. Cross-contamination between resin systems must be avoided.

Responsibilities of the user

Users are responsible for selecting appropriate materials, printers and workflows for their intended application.

Application-specific validation, regulatory compliance and final product qualification remain the responsibility of the user or device manufacturer.

3Dresyns does not assume responsibility for misuse, off-label applications or deviation from qualified workflows.

Governing principle

Vat photopolymerization materials are multivariable, system-dependent materials. Reported performance represents typical outcomes obtained under qualified workflows and is not an intrinsic property of the liquid resin alone.