RapidTool™ technology, also known as indirect metal powder laser sintering, is a groundbreaking method developed by DTM Corporation in the United States. This powder-based molding technique was created based on a patented technology from Texas University, and has become a key innovation in the field of rapid mold manufacturing. It is designed to provide a fast, precise, and cost-effective solution for producing metal molds, especially for injection molding and other manufacturing processes that require quick turnaround times.

Principles and Process Flow of RapidTool™ Technology

The RapidTool™ process involves several precise steps to create a fully functional metal mold. Here’s an in-depth look at how the process works:

1. Laser Sintering of Metal PowderThe first stage of the RapidTool™ method involves the use of CO2 laser technology to melt and fuse metal powder particles, which are coated with a binder. A 50W CO2 laser is employed in this process, and the metal powder is pre-coated with a thermoplastic polymer binder. The metal powder, typically low-carbon steel, has an average particle size of about 55 µm, while the binder particles are about 5 µm in diameter.The laser melts the binder, causing the metal powder particles to fuse together and form a semi-finished product. At this stage, the semi-finished mold is relatively brittle, with a strength of only 3 MPa. Care must be taken during handling to avoid damage to its fragile structure.
2. Sintering of the Semi-Finished ProductAfter the initial laser sintering process, the next step is sintering. The semi-finished product is placed in a furnace with an atmosphere consisting of 25% hydrogen (H2) and 75% nitrogen (N2). The furnace temperature is maintained at around 700°C. At this temperature, the binder is mostly removed, leaving behind a porous structure made of metal powder. The initial reduction process involves methane, which is then expelled from the furnace along with excess nitrogen and hydrogen gases. The combustion products primarily consist of carbon dioxide (CO2) and water vapor (H2O), with small quantities of carbon monoxide and nitrogen oxides, which are within environmentally safe limits.This sintering step results in a metal skeleton that is approximately 60% metal by volume and 40% voids, ready for further processing.
3. Copper Infiltration for Full DensityThe next step in the RapidTool™ process is copper infiltration. The semi-finished steel skeleton is placed into a furnace with a gas mixture of 70% nitrogen (N2) and 30% helium (He). Copper bricks are placed in the furnace at strategic positions, and the temperature is gradually raised to above the melting point of copper but below the melting point of the steel particles, around 1120°C. As the copper bricks melt, they infiltrate the porous steel skeleton through capillary action, filling the voids left by the binder and resulting in a fully dense, pore-free mold.
4. Final Processing and Mold AssemblyOnce the copper infiltration is complete, the mold undergoes additional processing steps. These include machining injection ports, cooling channels, and ejector holes that are necessary for the mold to function effectively in injection molding. After these steps, the mold is ready to be installed into an injection mold base, and the RapidTool™ mold can now be used for mass production.

Advantages of RapidTool™ Technology

• Speed and Efficiency: The RapidTool™ process significantly reduces the time required to produce functional metal molds compared to traditional methods, making it an ideal solution for rapid prototyping and low-volume production.
• Cost-Effective: This technology provides a lower-cost alternative to traditional manufacturing methods, particularly for industries that require fast mold creation without compromising on quality.
• Versatility: The RapidTool™ process can be used to create molds for a wide variety of materials, making it suitable for many different industries, including automotive, aerospace, and consumer goods manufacturing.
• High-Quality Molds: The copper infiltration process results in molds that are dense, durable, and capable of withstanding the demands of high-volume injection molding. The final product boasts a high thermal conductivity and excellent wear resistance.

Applications of RapidTool™ Technology

The RapidTool™ method is especially useful in industries where rapid mold creation and prototyping are crucial. These include:

• Injection Molding: Molds produced using the RapidTool™ process are ideal for injection molding applications, where fast turnaround times and high mold durability are required.
• Prototyping: Manufacturers can quickly create functional prototypes for testing and evaluation before moving on to high-cost, high-precision production molds.
• Low-Volume Production: For low to medium-volume production runs, the RapidTool™ process offers a cost-effective way to produce high-quality molds without the extended lead times associated with traditional mold-making processes.

Conclusion

The RapidTool™ method represents a significant advancement in the field of rapid mold manufacturing. By combining laser sintering, sintering, and copper infiltration processes, it enables the creation of highly durable, functional molds in a fraction of the time and cost compared to traditional methods. Whether for prototyping, low-volume production, or high-quality injection molding, RapidTool™ technology offers a versatile and efficient solution for manufacturers across various industries.