Foam Cutting: The Step by Step Process

water jet cutting machine cuts custom shapes in foam

If you’ve read our previous article on foam conversion services, you’ll most likely understand the basics of how we produce bespoke foam to hold and support your valuable equipment, with a perfect and accurate fit.

Foam cutting allows us to cut shapes and moulds out of foam with highly skilled methods for accurate precision. The three main methods of foam cutting include CNC routing, water jet cutting and die-cutting.

In this article, we talk you through the ways of foam cutting which we use at PottertonPacs, with step-by-step processes.

CNC Routing (Computer Numerical Control)

CNC Routing is used to create precise cuts at various depths in the foam. It’s the ideal method for creating very complex shapes, as they can be precision-cut at a high speed for a consistent and exact fit.

The process of CNC routing is fully computer-controlled, by using CAD (Computer-Aided Design) to route the plastazote into a designed shape and size. 

The process

To prepare for CNC Routing, we first create the design on our CAD drawing package, which will need to be accurate and to scale. The measurements added to the CAD package will need to take into account the lengths, widths and depths of the shape intended to be cut into the foam. Another step in preparing for CNC Routing is to ensure that the CAD settings are suited to the job, as the settings will be material-dependent.

The next step is choosing the tools needed for routing. You’ll usually want to use a rough cut tool and a cleanup tool to tidy up the cuts afterwards, giving a more precise and smooth finish.

Now that the CNC router is set up, the tools have been chosen and the design has been placed onto your CAD software, we’re ready for the next step, which is cutting. An off-cut can be used to test before cutting into the foam, to ensure that everything runs smoothly. Begin cutting the foam with the rough cut tool, whilst monitoring the CNC router at all times. Finish off by going over the foam with a cleanup tool.

Water Jet Cutting

Used as an alternative to CNC routing, water jet cutting has become the fastest-growing precision method for cutting materials, as it offers an accurate cut without interfering with the original structure of the foam.

It works by using an ultra-high pressure jet of clean water to cut the foam. The speed of a water jet is so high that it is three times higher than the speed of sound. Water jet cutting is generally suited to smaller projects as they can be very expensive to run and aren’t typically designed to work in higher quantities.

The process

Similar to CNC routing, water jet cutting works by adding the dimensions and the shape of the desired cut to a CAD program. The three main components of a water jet cutter include the control system, where the designs are created on a programming software; the machine; and the pressure system, which is where the water jet cutting takes place.

A stream of water is generated, with a pressure of around 94,000 psi, which is roughly 156 times more powerful than a fire hose. After this pressure is converted into velocity, it creates a powerful jet of water, which can be compared to the same size as a strand of hair. The stream of water is so powerful that it cuts materials four times the speed of sound. 


A die cutting machine is used to design custom cuts to materials when consistency is needed to produce repeated designs. The process press cuts component shapes into foam using a specialist cutting knife, which has to be created using specially fabricated blades. The blades are inserted into a plywood block to create the perimeter outline of the products or components to be held in the foam.  

Die-cutting is often compared to a cookie cutter in the way that a tool (commonly referred to as shaped dies) cuts through the foam, as the same shape can be cut out multiple times using the die cutter. However, different dies will need to be moulded to create different shapes.

Die-cutting allows us to create customised foam interiors to achieve a repeatedly accurate, high-quality finish at a competitive price. It’s the perfect tool to use when designing promotional materials or packaging solutions for larger quantities.

How can PottertonPacs help you?

Get in touch with a member of our team to discuss how we can help you to create your ideal equipment case with custom foam padding inserts. We will be able to talk you through the process, whilst helping you find the perfect case and customising options that suit you and your specific business needs. 

With one of the broadest ranges of bespoke interior solutions on the market, PottertonPacs are confident we will be able to propose a custom interior solution to suit your needs. We also offer custom fabricated, stitched, moulded and fabricated interior solutions too.