How to Dye and Post-Process Flexible Photopolymer Resins
As photopolymer 3D printing advances toward higher performance and greater flexibility, elastic and flexible resins are finding wider use—from soft prototypes and shock-absorbing pads to wearable enclosures. These rubber-like photopolymer elastomers are increasingly popular among designers and engineers alike. However, post-processing ‑especially dyeing‑ these materials remains a key challenge.
So today, let’s discuss the lesser‑known steps for photopolymer elastomer handling. We’ll also show how our 3D printing platform uses specialized equipment and protocols to achieve vibrant, durable, and repeatable results — even with complex materials like dual-component elastic photopolymers.
Why Post-Processing Flexible Photopolymer Resins Is So Challenging
Elastic photopolymer resins are commonly used in DLP and LCD 3D printing for their excellent elasticity and rubber-like feel. These materials can bend, stretch, and rebound, yet still maintain structural integrity — making them ideal for functional prototypes, medical-fit models, wearable parts, and demonstration pieces.
Popular applications today include 3D-printed shoes, wrist pads, rehab devices, and other soft, functional parts.
Despite their versatility, flexible resins come with unique post-processing challenges. The molecular structure and low surface energy of these materials often result in residual uncured resin after printing.
Even after initial UV curing, prints may feel dry on the surface but remain tacky or undercured internally. This prevents dyes from fully penetrating, leading to uneven, faded or shallow color unsuitable for aesthetic or functional use.
Beyond dyeing, post-processing challenges include:
- Support removal: mishandling can deform the part or cause irreversible cracks.
- Sanding damage: elastic surfaces scratch or tear easily, spoiling finish and integrity.
- Thermal curing risks: poor temperature control can degrade elasticity, shrink the part, and impair performance.
Thus, effective resin 3D print post-processing is a complex workflow—cleaning, curing, sanding, dyeing, and sealing—and requires professional-grade equipment and proven protocols, backed by experienced 3D printing service providers .
How to Post-Process Flexible Photopolymer Resins
We’ve developed a professional post-processing workflow tailored to elastic resin 3D printing materials — especially dual-component photopolymer elastomers and flexible resins. Here’s what the process typically looks like:
Dual ‑ Stage Cleaning
Use a two-tank cleaning system. The first rough wash removes surface resin residues, while the second uses ultrasonic agitation to dislodge any resin trapped deep within lattice structures—ensuring a thoroughly clean surface.
Air Drying + UV Pre-Cure
Hang and air-dry printed models, then perform a first UV cure to strengthen the surface, transitioning from tacky to dry-touch—preparing for dyeing.
Thermal Post-Cure
Apply heat curing to complete crosslinking of elastic chains, promoting internal strength and flexibility—critical for dual-component elastomer systems.
Photopolymer Elastomer Dyeing
In response to common dyeing challenges—fading, uneven color, and poor adhesion of photopolymer elastomers, we employ the HAM-PD400, an intelligent Dyeing Machine for 3D Printed Parts developed in-house by HPRT.
The HAM-PD400 uses a liquid-immersion process combined with a thermostatically controlled hot-dyeing system (up to 115 °C) and directed-airflow penetration technology. It delivers deep, uniform, and long-lasting color across the entire build volume within just 120–150 minutes. The intelligent dyeing system is specifically optimized for photopolymer flexible resins such as TPU-based materials and DLP/SLA elastomers.
Compared to manual dyeing, HAM‑PD400 delivers:
- Deep dye penetration into microstructure for vibrant, fade-resistant color
- Multiple dye tank sizes + Pantone matching, supporting batch consistency and customization
- Smart cartridge recognition ensures precise dye usage and avoids waste
- One-step dyeing and rinsing keeps operations clean and safe
- Integrated dye/cleaning workflow for efficiency and cleanliness, compatible with various 3D printing technologies (SLA, DLP, LCD, SLS, MJF, SAF, etc.)
- Material-specific dye recipes and temperature profiles tailored to resin types, maximizing compatibility
In practice, we achieve consistent, precise, durable color—even on complex elastomer parts like flexible damping components or wearable shells—enhancing both function and perceived quality.
Surface Coating (Optional)
For display-grade or high-use parts, apply a clear matte lacquer. This not only enhances feel and finish but also protects the dye from abrasion and oil.
Dyeing and Post-Processing Services for 3D-Printed Elastomers and Photopolymer Resins
We are a full-service 3D printing and post-processing platform, offering one-stop solutions from modeling and printing to surface finishing, dyeing, and final delivery.
For the post-processing needs of photopolymer elastomers and dual-component lattices, we provide:
- Standardized processes & engineering experts for consistent quality
- Flexible dyeing solutions that accommodate multi-color, multi-material, and multi-batch requirements
- High-precision equipment to support stable, high-volume production
- Support for small-batch prototyping and sample validation before full orders
We've worked with footwear brands, robotics manufacturers, and ergonomic product developers to deliver proven post-processing and dyeing solutions for two‑part flexible photopolymer and elastic resin materials. Examples like:
- 3D-printed one-piece clogs and sandals
- Wrist protectors for soft robotics
- Soft-touch keyboard pads and ergonomic mouse rests
Many makerspaces and design academies also trust us for advanced techniques like gradient dyeing, selective color masking, and and multi-color zoning — effects that are difficult or impossible to achieve with DIY tools.
If you're seeking a professional platform for photopolymer post-processing, we're a trusted partner. With standardized workflows and precision equipment, we ensure flexible prints are finished to perfection—resilient, vibrant, and refined in both texture and appearance.
Contact our team to request a sample or customized solution—and experience the quality difference that professional post-processing can bring.
FAQs on Dyeing and Post‑Processing Flexible Photopolymer Resins
Q1: Can all elastic resins be dyed?
A: Most flexible photopolymer resins — including Tough and Flex types — are dyeable. Materials with higher transparency and lower hardness generally absorb color more easily.
Q2: Will dyeing affect elasticity?
A: No. Our process has been tested to preserve the elastic network structure. Parts retain their full stretch and rebound properties after dyeing.
Q3: Can I request multi-color or patterned dyeing?
A: Yes. We support multi-color and zone-specific dyeing. Patterned or masked dyeing requires specialized techniques and may incur additional costs — please contact us for custom solutions.