Thermwood's Cut Layer Additive process trims waste in mold building

Sept. 18, 2023
The three-axis CNC router can be used to create an economical aluminum mold from metal sheets rather than machining it from a solid billet.

Cut Layer Additive (CLA) Thermwood has developed an additive manufacturing process it calls Cut Layer Additive (CLA). The company’s CLA machine is a three-axis CNC router that can be used to produce prototypes, lay-up tools, molds for validating mold design, or end-use aluminum molds for processes such as thermoforming, blow molding, rotomolding and reaction injection molding. The CLA machine has a 5-foot-by-12-foot table that uses a version of Thermwood’s most advanced controller. Users import a 3D CAD file to the CLA machine’s control system, which then walks them through menus involving a number of variables, including raw material sheet thickness, how much trim stock to allow for, the number of pieces to be cut, and the method for attaching the pieces. The control system then optimally nests pieces to be cut from each sheet to maximize material usage. Then, the CLA machine cuts each piece from the sheet, and an inkjet printer attached to the router head prints each piece with a unique code indicating the layer and sequence for attaching pieces, as well as a QR code. While additional sheets are being cut, a worker attaches the pieces in a layer with an optional puzzle joint, inserting dowels to align layers, and joining layers with adhesives or bolts. As with all large-format, near-net additive systems, once the near-net part is fully assembled, users employ an appropriately sized five-axis CNC router — which Thermwood also manufactures — to machine the part to its final dimensions and finish.

What’s new? Thermwood’s CLA machine.

Benefits Material and cost savings. Creating an aluminum mold from metal sheets using the CLA machine produces a fraction of the waste material that would come from machining the same mold from a solid billet, and also costs much less. Depending on the material used, the machine’s speed can outstrip other modes of production, such as 3D printing. The control system can prioritize cutting pieces for the first layers of the finished piece, allowing assembly to begin while additional sheets of material are being cut. The CLA machine works with a wide variety of materials available in sheet form, including polymers and aluminum — as well as materials that cannot be 3D printed, such as wood. The intuitive software in the controller doesn’t require a user to understand CNC programming.

Thermwood Corp., Dale, Ind., 812-937-4476,

About the Author

David Tillett | Associate Editor

Associate Editor David Tillett writes and edits for Plastics Machinery & Manufacturing, Plastics Recycling and The Journal of Blow Molding. He covers new products, industry news, patents and consumer and business equipment. He has more than 20 years of experience in daily newspaper, online and magazine journalism.