Low Formaldehyde & High Strength｜3D‑Printing Resin Empowers Efficient Production of Complex Valve Sand Cores
2026-08-24 09:02Sand mold 3D printing technology represents a revolutionary breakthrough in the foundry industry, and has become one of the key technologies for rapid manufacturing of complex‑structure components in modern manufacturing. Combining computer‑aided 3D design, additive manufacturing principles and foundry processes, it realizes mold‑free rapid forming of sand molds. Complex sand molds can be directly produced by bonding raw sand layer‑by‑layer, which is especially suitable for manufacturing high‑precision complex castings in small‑to‑batch‑size production.
Valve castings feature sophisticated structures with curved internal flow channels, bringing great challenges to core‑making. Strict requirements are placed on sand core surface finish, strength and gas emission during production. Xinda focuses on the R&D of furan resin for sand‑mold 3D printing. Traditional furan resin is modified to develop special resin binders, taking multiple critical foundry indicators into consideration, including ambient‑temperature strength, gas evolution, shake‑out performance and environmental‑friendliness. The 3D‑printing resin together with its matching curing agent is adopted for valve sand‑core printing, to solve forming and performance‑related issues of complex valve sand cores.
Ⅰ、Key Technical Specifications of Products
| 3D Printing Resin | |
| Density (20℃) | 1.10‑1.20 g/cm³ |
| Viscosity (20℃) | 9.50‑10.5 mPa·s |
| Free Formaldehyde F.F. % | ≤0.1 |
| Nitrogen Content % | ≤0.5 |
| pH Value | 6.0‑7.5 |
| Particle Size μm | ≤0.5 |
| 3D Printing Curing Agent | |
| Density (20℃) | 1.20‑1.30 g/cm³ |
| Viscosity (20℃) | ≤15 mPa·s |
| Total Acid % | 18‑20 |
| Free Acid % | ≤1.5 |
Ⅱ、Production Process & Application Parameters
| Base Sand AFS | 63‑65 |
| Resin Addition Level (based on sand weight) | 2.10% |
| Curing Agent Addition Level (based on sand weight) | 4.0‰ |
| Layer‑Coating Thickness | 0.4 mm |
| 2‑hour Tensile Strength of Sand Mold | 0.67 MPa |
| 24‑hour Tensile Strength of Sand Mold | 1.52 MPa |
| Formaldehyde Emission at 3D‑Printing Site | 0.0317 mg/m³ |
Ⅲ、Practical Application Results
Low‑viscosity and high‑cleanliness resin ensures stable and smooth printing performance;
Formulated with mixed sulfonic acid, the curing agent delivers good flowability for favorable sand‑laying effect. It features low corrosiveness and will not damage sand‑mixing and sand‑laying equipment;
Low emission of harmful gases during core‑making process;
Sand cores achieve smooth surface and high strength, meeting production requirements for valve castings with complex inner cavities.
Xinda 3D printing resin and matching curing agent is well‑suited for 3D‑printing production of intricate valve sand cores. It provides stable printing performance and low equipment corrosion. The sand cores obtain excellent strength and surface quality, accompanied by low formaldehyde emission on‑site. Balancing casting quality and environmental‑protection requirements, the product is applicable to additive core‑making for various complex valve‑type castings.