I. Industry Pain Points of Traditional Surface‑Treatment Masking Processes

The masking process is one of the most resource-intensive steps in the surface‑treatment workflow. In many factories, the masking station accounts for roughly 15% of the workshop’s total workforce and relies heavily on skilled operators performing the tasks manually, giving rise to multifaceted production challenges.

First, Highly dependent on human input, with insufficient consistency and scalability. Tape cutting, varnish application, and plug assembly all rely on manual expertise, leading to variability in mask‑edge quality depending on the operator. In the aerospace industry, where strict OTD (On-Time Delivery) and OQD (On-Quality Delivery) standards prevail, manual processes are prone to defects such as missed masking, edge lifting, and chemical penetration, resulting in rework or even scrap and preventing stable, large‑scale replication. For components with complex cavities, irregular grooves, or non‑standard openings, standard plugs and ordinary tapes often fail to achieve a tight seal, further increasing the risk of protective‑layer failure.

Second, Long delivery cycles and weak emergency response capabilities. Traditionally, custom masking tooling typically requires external mold development and outsourcing, with mold‑making lead times often stretching to several weeks. When faced with scenarios such as on‑ground aircraft standby repairs, new‑product prototype iterations, or urgent small‑batch orders, this long‑cycle tooling approach fails to meet rapid production demands, significantly delaying product development and emergency fault‑repair timelines.

Third, Material waste and safety and environmental concerns are particularly acute. Adhesive tapes and peelable varnishes are largely single-use consumables; once a batch has been processed, they are discarded outright, generating substantial industrial solid waste. Solvent-based masking coatings contain volatile hazardous substances, necessitating comprehensive ventilation and protective measures in the workshop, thereby increasing the EHS management burden on the plant. Moreover, some varnishes leave behind low‑molecular‑weight residues after processing, which can constitute serious quality defects in high‑precision aerospace and medical components.

Fourth, Process fragmentation drives up overall production costs. Masking is interwoven into every stage of surface‑treatment processes; before and after each operation, masking must be applied and subsequently removed, thereby extending the overall processing time. When labor hours, outsourced tooling costs, and scrap‑part losses are factored in, the unit production cost rises significantly. Under a multi‑variety, small‑batch production model, the cost disadvantage of traditional masking is further exacerbated.

II. Core Advantages of Lynxter Silicone Printing Material in Mask‑Making Applications

Mask‑tooling materials must simultaneously meet stringent requirements, including high‑temperature resistance, chemical corrosion resistance, elastic sealing, freedom from solvent contamination, and adjustable hardness. Lynxter’s proprietary industrial‑grade liquid silicone material is specifically engineered for demanding surface‑treatment applications and, when paired with the S300X series printers, enables the integrated one‑step molding of mask components.

First, the material is available. Chemical inertness and wide-temperature-range tolerance This series of silicone products is solvent-free, ensuring high safety in workshop applications. With a heat resistance exceeding 250°C, it is compatible with a wide range of extreme process conditions, including plasma spraying, high-temperature curing of powder coatings, and wet chemical immersion. It withstands exposure to various acidic and alkaline plating baths and the impact of plasma flames without melting, swelling, or decomposing—thus preventing contamination of the workpiece.

Secondly, Wide hardness range and excellent sealing performance. The material’s Shore A hardness ranges from 5 to 70, enabling the fabrication of both soft, stretchable flexible mask strips and rigid, high‑hardness, dimensionally accurate sealing plugs and gaskets. The elastic silicone conforms closely to complex part geometries, creating a reliable sealing interface that effectively prevents coatings and chemical agents from seeping into protected areas through gaps, yielding crisp, well‑defined masking edges and significantly reducing rework rates. After printing, the silicone exhibits isotropic mechanical properties comparable to those of traditionally injection‑molded or vacuum‑cast silicone, while the mask tooling can be cleaned and reused, minimizing material consumption and lowering ongoing production costs.

Third, the material portfolio is extensive, addressing compliance requirements across multiple industries. In addition to the general‑purpose industrial SIL‑001 silicone, we also offer medical‑grade compliant silicones, supporting surface‑treatment applications in the biomedical field—such as plasma coating of implantable prostheses—and expanding the scope of mask‑making applications in the medical sector.

III. The Process Value of Silicone 3D-Printed Masks

Leveraging the S300X‑LIQ21 and LIQ11 equipment, companies can independently design and 3D-print mask tooling on-site, delivering end-to-end value improvements compared to conventional processes.

3.1 On-demand manufacturing, shortening delivery lead times

Masking tooling is driven directly by CAD 3D models, eliminating the need for mold fabrication and removing minimum order quantity constraints. The traditional lead time of several weeks for custom tooling has been reduced to just a few days—or even hours. For new‑product prototyping and AOG (Aircraft on Ground) emergency repairs, it can rapidly produce tailored components such as plugs, sealing rings, and localized masking sheets, significantly enhancing manufacturing agility and shortening time‑to‑market. Meanwhile, all production data is stored as digital files, enabling full production traceability and meeting the quality‑system requirements of the aerospace and defense industries.

3.2 Adapts to complex geometries, reducing human error

For complex geometries that are difficult to handle with conventional tooling—such as irregularly shaped openings, deep grooves, and thin-walled curved surfaces—3D printing can precisely replicate the part’s contours to create customized masking molds, thereby eliminating human‑induced errors associated with manual tape application. Aligned with today’s manufacturing trends of high mix, low volume, 3D printing enables a single system to rapidly switch between producing masks for multiple distinct parts, eliminating the need to maintain large inventories of physical tooling.

3.3 Cost reduction and waste minimization, optimizing production line bottlenecks

Silicone mask tooling is reusable multiple times, significantly reducing solid waste generated by adhesive tape and single-use varnishes. By bringing mask‑tooling production in‑house from outsourced processes, mold‑tooling costs are eliminated. Manual mask‑application and removal operations are minimized, freeing up skilled operators and alleviating bottlenecks at the masking station. Real‑world data from select customers show that mask‑related setup time can be cut by 50%–60%, scrap rates are reduced, and overall operating costs are optimized.

3.4 Compatibility with Diverse Surface Treatment Processes

The printed silicone mask tooling is compatible with a wide range of mainstream surface‑treatment processes, including wet anodizing, chemical immersion, plasma spraying, powder coating, and sandblasting. A single masking solution addresses multiple process scenarios on the shop floor, offering high versatility and facilitating centralized management of the mask‑tooling inventory across the production line.

IV. Equipment Technical Principles and Operational Workflow

The Lynxter series 3D printers utilize Liquid Additive Manufacturing (LAM) technology. Equipped with an IDEX independent dual-extruder head and a micro‑dose metering pump, this system is specifically designed for additive manufacturing of liquid silicone and polyurethane materials. The equipment also supports the printing of soluble sacrificial support structures, addressing the challenges of fabricating complex overhanging features and masked components.

4.1 Core Technical Principles

The equipment employs a two-component liquid silicone feed system: the A and B silicone precursors are separately delivered to two high-precision volumetric metering pumps, where they are precisely blended at the pump outlets. The resulting liquid silicone is extruded through replaceable nozzles with aperture sizes ranging from 0.23 mm to 1.04 mm. The silicone is deposited in bead‑like filaments, layer by layer; upon contact between the two components, a crosslinking chemical reaction is initiated, gradually transforming the liquid silicone into a solid elastomer that exhibits elasticity, heat resistance, and chemical resistance.

IDEX’s dual‑nozzle architecture features one nozzle for printing the functional silicone mask body and a second nozzle for depositing water‑soluble sacrificial support material. When the mask fixture includes complex structures such as overhangs or cantilevers, the support material ensures structural integrity throughout the printing process and can be dissolved in water after printing, eliminating the need for time‑consuming mechanical post‑processing. The resulting silicone parts exhibit mechanical properties comparable to injection‑molded silicone, seamlessly balancing additive‑manufacturing design freedom with the performance standards of industrial materials.

4.2 Work Process

1.  3D model design Engineers use general-purpose CAD software to design three-dimensional models of mask plugs, sealing rings, and shielding plates based on the protection zones of the parts being processed, ensuring precise alignment with the parts’ holes, grooves, and curved surface contours.

2.  Slice processing : Import the 3D model into slicing software, set process parameters such as layer thickness, extrusion flow rate, and print path, and generate G-code recognized by the printer.

3.  Equipment printing and forming : Upload the G-code to the S300X printer; the two-component silicone is mixed by a metering pump and deposited layer by layer through the nozzle, with crosslinking beginning as soon as the silicone exits the nozzle. The curing process can be accelerated by heating the print chamber or by baking in an oven after printing.

4.  Post-processing and Commissioning : Once the silicone print has fully cured, remove the supports—no additional complex post‑processing is required—and it can be directly assembled onto the workpiece and proceed to surface‑finishing operations. After use, the silicone mask can be cleaned and stored for reuse in subsequent production runs.

V. Relevant Application Cases

Case Study 1: Plasma-Sprayed Masking in the Aerospace Industry (APS Coatings × Lynxter)

APS Coatings is a service provider specializing in plasma thermal spraying for aerospace, defense, and related industries. During ceramic plasma‑coating processes, certain precision holes and grooves must be rigorously protected. Traditional methods—relying on hand‑applied masking tape or custom metal tooling—result in long development cycles and high costs for small‑batch prototype production. Under the extreme thermal conditions of plasma spraying, the sealing integrity and heat‑ and impact‑resistance of the mask directly determine part yield. Conventional masking approaches struggle to balance complex contour compliance with process robustness, whereas 3D‑printed silicone custom masks offer a viable solution.

The video below provides a comprehensive demonstration of the entire process, from 3D‑printing and assembling the silicone mask to its application on the component, followed by plasma spraying and, finally, the removal of the mask after coating. It clearly illustrates the real‑world performance of the custom‑designed silicone mask under thermal‑spraying conditions.

Custom silicone mask plugs are printed using the S300X‑LIQ21 system. For a 25 mm × 7 mm × 5 mm‑sized mask, 27 mask components can be printed in just 30 minutes. The printed silicone masks withstand high‑temperature plasma jet impacts, fit tightly into the part’s recesses, and create sharp masking edges; after coating, the masks can be removed directly, leaving the protected areas free of any coating residue. This solution supports both rapid prototyping and small‑ to medium‑batch production, shortening the development cycle for mask tooling while meeting the stringent quality requirements of aerospace components.

Case Study 2: Wet Surface Treatment Masking for Spi Aero Aerospace Components

Aerospace aluminum alloy cylindrical components require multiple wet‑process surface treatments, including anodizing, primer coating, and topcoat application. The outer surface of the component features numerous irregularly shaped slots and holes, while the interior contains annular grooves; each process necessitates region‑specific protective measures. Traditionally, this was accomplished using a combination of numerous standard plugs and adhesive tape, resulting in lengthy assembly times and frequent defects caused by chemical agents seeping into gaps. Moreover, specialized tooling had to be outsourced for custom fabrication, leading to extended lead times.

Using Lynxter’s silicone 3D printing, a complete mask assembly—comprising an outer‑ring seal, an internal groove retainer, and an external custom‑shaped slot plug—can be printed in a single run. The entire silicone mask snaps into place for secure installation, delivering consistent sealing performance; the parts can be directly immersed in chemical‑treatment baths to undergo anodizing. During process transitions, select mask components can be quickly removed to facilitate switching to coating operations. The masks are washable and reusable, reducing tape waste and significantly cutting mask‑preparation lead time, while meeting the demands of multi‑step, continuous surface‑treatment processes for aerospace components.

Case Study 3: Production Line Upgrade at the Electroplating Company L’Electrolyse

Electrolyse specializes in electroplating and coating, with a large volume of parts requiring mask protection. The company has implemented the S300X‑LIQ21 system to autonomously produce various silicone plugs, peel-off stoppers, and paint‑masking fixtures. These silicone masks exhibit excellent chemical resistance, remaining intact without swelling or degradation even in highly corrosive plating baths, and leave no residue upon completion of processing.

The equipment operates 4–5 days per week, and two operators can handle mask design and printing, eliminating full reliance on externally sourced custom tooling. Compared with conventional processes, mask‑station setup time is reduced by 50–60%, labor intensity is lowered, and mask‑process consistency is improved. Additionally, the working environment is enhanced, solvent‑based mask materials are used less, and workshop EHS risk points are optimized, making this system an essential supporting tool for production‑line tooling.

Case Study 4: Application of Silicone Masks in Powder Coating Processes

For sandblasting and powder coating of motorcycle engine valve cover components, the mating holes and sealing grooves must be protected. The powder‑coating bake temperature approaches 200°C, at which point conventional masking tapes and plastic plugs lose their effectiveness. By using Lynxter SIL‑001 (45A) silicone to fabricate a custom mask that conforms precisely to the part’s contours, the mask can withstand both the impact of abrasive particles during sandblasting and the high temperatures of powder curing. After coating is complete, the silicone mask is removed, leaving the protected areas clean and free of powder contamination—making this solution ideal for surface‑treatment applications such as repair and refurbishment, or small‑batch modification projects.

Silicone 3D-printed engine air‑intake cover with a pressure‑relief valve interface, along with a 3D‑printed mask component (blue part)

Various types of 3D-printed silicone lids