What Is The Best Method And Equipment For Cutting Flexible And Soft Foam?

By Author: Sigal Barnea
Total Articles: 5
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Soft and flexible foam, such as Polyurethane, Polyethylene and EVA have always been a bit of a challenge to cut. Soft PU (Polyurethane) and upholstery foam tends to bring out toxic fumes if being cut on a CNC hot wire foam cutting machine and cannot be held down properly when trying to machine it on a CNC router. It is hard to yield nice and clean edges cut trying to hot wire cut, laser cut or machining PE (Polyethylene) as the edges tend to be rough and fuzzy. And, EVA tends to move when trying to laser cut it, resulting in inaccurate cuts that might deviate from the original desired dimensions.
So, how do one produce nice, clean, neat and smooth edges when trying to cut flexible or soft foam?
There are several options for cutting flexible foam, including manual cutting, bandsaw machine, abrasive wire cutter or Oscillating blade knife cutter.
Manual cutting with scissors, with a saw, or with a turkey knife and without the proper tools or machinery can be messy, difficult and very inaccurate. The cuts can be distorted or inconsistent as there is no guidance. Also, there are types of foam that are almost impossible ...
... to cut manually, especially upholstery foam

Bandsaw cutter uses a table and blades able to cut the foam vertically or horizontally, providing a quick and clean cut all the way through without ripping or tearing the foam. It is useful for cutting medium to firm upholstery foam because the blades stay square to the material. The bandsaw is a highly specialized tool that only does one thing – cutting foam, but it can be very pricy, especially if anyone is in need of a larger machine. The bandsaw can cut EVA, Polyethylene, Polyurethane, Polypropylene, Nitrile foam and foam rubbers. It is typically used for fabricating foam pads, blocks and gaskets, foam packaging and composites.
Another option is using an abrasive wire machine (also known as fast wire cutter) allowing cuts to be made with a very fine saw-like cut. This is a CNC cutter similar to a wire saw, that uses endless running high-speed abrasive steel wire to perform cuts. The machine features a high-speed electric motor driving an abrasive wire that can cut through a variety of materials, including EPS, XPS, EPP, PU and PE foam. Its common application is for the furniture and upholstery industry, for thermal and acoustic insulation, packaging, composites and cutting SIP panels for construction. The cuts usually come out clean and consistent, without any defects due to the powerful motor of the abrasive wire.
The last method is the one we recommend the most – The Oscillating knife CNC foam cutter uses a
blade in an up and down speedy vibration motions (tens of thousands of times per minute) to achieve cutting. The blades are easily changeable according to the material that needs to be cut. The finished cut products are clean with smooth edges. This machine makes it possible to cut materials that cannot be nicely cut, if at all, with any other foam cutting machinery such as a router, hot wire cutter or a laser cutter. The Oscillating knife cutter also eliminates the irregularities and rough edges, especially with the soft flexible foam, providing high speed, and no deformation. The Oscillating knife can cut soft Polyurethane (PU), Polyethylene (PE & XPE), EVA foam, Cardboard, corrugated plastic, foam core, rubber & Sponge foam, latex foam, PVC, carbon fiber, leather and silicone rubber.
Soft Polyurethane is a hard material to be routed or machined – the material is hard to hold down, it moves when the tool hits it and the spindle usually rips it off. When using a laser cutter to cut EVA foam, the edges tend to burn (this is especially more noticeable with the light EVAS material) and the material tends to move resulting in an inaccurate and distorted cut. Same goes to Polyethylene that tends to be hard to hold down on the CNC router table.
The Oscillating knife cutter can cut all these types of foam quickly and without distortion, with nice edges and accuracy. It is especially used for industries such as automotive (for cutting seats, cushions, interiors), fashion (for cutting leather), for packaging industry (cutting inserts), as well as for cutting mattresses and furniture.
So, although there are several methods for cutting soft flexible foam, it seems that the Oscillating knife cutting is the preferred method, folding many advantages, such as:
- Best return on investment as the machine is not too expensive
- Cutting accuracy and high precision
- Easy to operate and handle
- High speed - Saves time on production and manpower
- Eliminates distortion and rough edges, as the edges come out neat and clean
- Environmentally friendly – does not yield air pollution, does not produce odor

WeCutFoam was founded in Silicon Valley, CA in 2001. The company specializes in customized cutting shapes out of almost any type of foam, wood and plastics. The company creates props for movie sets and theaters, dimensional signs, letters, logos, architectural shapes, museums and galleries exhibits, trade show displays, parade floats and more. Full-scale oversized 3D shapes are fabricated, including race cars, planes and oversized props, providing coating, painting and 3D printing services as well.
To learn more visit https://www.wecutfoam.com email sales@wecutfoam.com or call 408-454-6163

Electrical engineer with over 30 years experience with software, hardware and motion control. Owner of Foamlinx LLC, designing and manufacturing CNC foam cutting machinery as well as WeCutFoam, providing custom foam cutting, machining and prototyping services.