How to Cut Foam? Tutorial.

These foams are made for different purposes:

• Upholstery & couch cushions
• High-density foam roller
• Insulation panels
• Sponges
• High-density foam mattress
• Sport (e.g. yoga mattress)
• Sport underlays (under sport machines)
• Foamboard
• Packaging foam
• Insole shoes

You can buy custom-shaped foams for your use, or you can buy mattresses, cushions, covers, and seats pre-made. If the purchased foam doesn’t match your needs, you can cut it as well. Read our tutorial about how to cut a foam cushion.

Cutting foam at home with different tools

What will you need for cutting foam? Well, there are many ways to complete this task: the cheap way, the expensive way – and of course, the best way. You will need the following supplies:

• The sheet of foam
• A long (with a longer blade than how thick the foam is) knife, preferably a utility knife
• A drywall panel or a piece of hardboard (used as a ruler or a layer underneath the foam to keep the straight lines)
• Tape measure and marker
• A sharpie
• Scissor in case of thin foams

If you cut polystyrol, the best option is to buy (or rent) a foam cutting saw, but its price is between 200-500$. However, a foam cutting saw can prevent friction and keeps the blade straight to make the best cut.

PE foam cannot be cut by the foam cutting saw, for that, you will need the utility knife.

What is the best way to cut foam?

The best ways are all industrial solutions. The cutting method is determined based on the product’s parameters (length, thickness) and the quantity. The questions are: which method is feasible? Which one is faster? Which is more economical?

• plotting (with a CNC-controlled oscillating knife)
• Die-cutting
• Waterjet-cutting
• Via CNC router
• Endless blade
• Laser
• Wire-cutting

How the professional companies cut foam?

Plotting with oscillating knife

Plotting is a CNC-controlled process, only available for professional companies. Vacuum tables are needed for this, that allows full access to all sides of the material (except the side that is contacting the vacuum table).

The oscillating knife is vibrating up and down, moving forward, thus cutting the foam.

This method is preferably used when the goal is only to incise the foam but not cut it completely.

Die-cutting

Die-cutting is an easy way to cut out an exact shape with a machine and a die. The die-cutter is pressured to the foam (horizontally). The strength of the pressure is based on the foam’s thickness.

At one time, multiple layers can be die-cut.

Waterjet-cutting

With waterjet-cutting we are using an extremely high-pressure jet of water in order to cut the foam. The speed and the quality of cutting is reduced while cutting high-density foams (smooth edges and sides are not guaranteed).

Via CNC router

With a CNC router, 2.5D and 3D shapes can be cut. Mostly the packaging industry uses it to produce custom box inserts. It is a slow, yet very precise way to cut a foam.

This method is also capable of just incising the foam.

Endless blade

Professional companies can cut foam with an endless blade that is able to cut the foam completely. The industrial usage of this is to create samples.

Manual and automatic devices are available for purchase for home too.

Laser

A CAD (Computer-aided design) is needed for laser-cutting the foam. It’s a costly technology, but one of the most perfect foam-cutting method.

Wire-cutting

Wire-cutting is similar to the infinite blade technology, but in this case, a wire replaces the blade. The cutting surface will be rougher with wire-cutting.

How to cut foam horizontally?

We do not recommend cutting your foam horizontally, definitely at home, because it will be inaccurate. Cutting horizontally is more expensive because companies need better tools to succeed.

Foam producers use a splitting machine to cut the foam horizontally. High precision is needed, because every millimeter matters.

Splitting machine constricts the foam between rollers and then cuts it with a blade. The height of the blade can be set manually and automatically too.