AM Molding & Forming Tools

Lost-Wax/PLA Casting (Ceramic Slurry)

• Using AM, a PLA/wax model is 3D printed and coated in ceramic slurry. After burning out the PLA/wax, molten metal is poured in, enabling detailed and intricate castings.

Silicone

• A 3D-printed model is enveloped in silicone to create a flexible mold. This mold is ideal for casting various materials due to its flexibility and chemical resistance.

Resin

• A mold is made from a 3D-printed model, and a two-component polymer resin is poured in. This method offers detailed parts in diverse finishes and properties, suitable for prototypes and artistic pieces.

Molding processes that predominantly rely on pressure to shape materials are widely utilized across various industries. A key challenge within this category of molding is the inherent elasticity of materials, leading to a phenomenon known as "springback." Springback often results in pressure-formed materials failing to conform precisely to the mold's intended shape. This can be compensated for in two possible ways:

1. Pre-Mold Compensation, which involves making adjustments to the initial design or geometry of the mold or tooling to account for the anticipated springback effect. This proactive approach aims to achieve the desired final part shape by incorporating specific modifications into the mold's geometry or dimensions. Common pre-mold compensation techniques include:

   • Die Design Modification: Altering the die or mold cavity geometry to compensate for the expected springback. This may involve adjusting angles, draft angles, or incorporating additional features to counteract the material's elastic tendencies.

   • Material Selection: Choosing materials with properties that minimize springback effects. Materials with lower elastic modulus or higher ductility may exhibit reduced springback, making them more suitable for specific molding applications.

   • Temperature Control: Controlling the temperature of the material during the molding process can influence its elasticity and reduce springback. Elevated temperatures can enhance material flow and reduce its tendency to rebound after molding.

2. Post-Mold Compensation,  strategies involve addressing springback issues after the molding process is completed. This approach recognizes that despite proactive measures, some degree of springback may still occur. Post-mold compensation methods include:

   • Heat Treatment: Applying controlled heat treatment to the molded part to manipulate its material properties and reduce springback. This can involve annealing or stress relieving the part to minimize residual stresses and improve dimensional stability.

   • Secondary Machining: Employing machining processes, such as milling or grinding, to remove excess material and achieve the desired final dimensions and shape. This approach is particularly useful when precise tolerances are required.

   • Resin or Material Blending: Mixing materials with different properties to create a composite that exhibits reduced springback. This can be an effective way to tailor material behavior to specific molding applications.

   • Forming Aids: Utilizing additional tools or fixtures, such as jigs, templates, or fixtures designed with an awareness of springback, to reshape the molded part to its intended dimensions after the initial molding process.

Specific types of molding processes/tooling that fall under this category include:

1. Forged Composite AM Molds

   • Forged composite is a type of advanced carbon fiber-reinforced polymer that is pressed under high pressures to create strong, lightweight components. AM molds can be designed to shape these materials, providing the ability to produce intricate geometries that may be difficult with traditional molds. The molds guide the forged composite material into the desired shape during the high-pressure forming process.

2. Dimple Dies

   • Dimple dies are specialized tools employed to introduce recessed patterns or dimples into materials, often used in applications like sheet metal fabrication.

3. Bend/brake Dies

   • Bend and brake dies are essential tools in sheet metal forming processes, used to shape metal sheets by bending or folding them at precise angles.

Injection Molding

• Using AM, molds for injection molding can be swiftly produced, especially for short-run parts. These molds, typically designed to withstand high temperatures, allow melted plastics to be injected and solidified into desired shapes.

Blow Molding

• AM can create molds used in blow molding, a process where heated material is blown into a mold to form hollow objects. AM accelerates mold design and testing, providing flexibility in adapting to design changes.

Metal Injection Molding (MIM)

• AM assists in designing tools and molds for metal injection molding, where metal powders mixed with binders are injected into molds. Once in the mold, high temperatures are used to remove the binder and sinter the metal. AM enhances rapid prototyping and customization in this high-temperature process.