长江材料：公司有生产用于砂型3D打印的3D打印砂，未来会继续做大3D打印砂产品

Group 1 - The company produces 3D printing sand used for sand mold 3D printing [2] - The company plans to expand its 3D printing sand products and provide sample trial services using 3D printing technology [2] - The focus is on enhancing the application of related technologies and products in the casting industry [2]