How Does Compression Cutting Work for Foam?

Have you ever wondered how some of your comfiest pieces of furniture came to be? Cutting and trimming some things, such as foam mattresses or chair cushions, with straight lines and 90 degree angles seems pretty basic. But what about that contoured memory foam pillow or the cushioning foam pad with curved cutouts that hug your hips at night? Or how about the custom foam packing materials you ordered for your company’s new product? Surely, their smooth angles and clean curves would be next-to-impossible to cut by hand while still being sold at a reasonable price. So what’s the secret to making these pieces of foam? In many cases, these special designs are produced using compression cutting technology.

The process of making contoured foam involves molds that manipulate pressure dispersion as a blade passes through the foam material. Templates are produced on a CNC router, typically from wood, which will reflect the ultimate appearance of a product. Foam is placed over these templates, compressed, and passed through the machine as a blade slices through the foam, directly above the mold. This compression cutting generates two interlocking forms; the section that was forced inside of the template during compression, and the piece cut off the top, above the blade. Raised areas in a template create greater levels of compression, which means more foam gets squeezed into that area. When released, this turns into a high point on the actual foam form as it expands. This method is often used to create snug packing foam and zoned mattresses for bedding.

These computer-cut, foam-forming templates are able to be made in nearly any pattern or design, featuring contours, curves, edges, and tapers. The only thing that preventing this process from forming full 360 degree moldings is the flat side that is left from the cutting of the blade.