Beginner’s Guide to CNC Cutting for Plastic and Foam Packaging

Different products have unique requirements depending on their design and specifications. One such consideration is the casing or packaging requirements of the item.

Given its vital role in the logistical and transportation sectors, packaging elements are crucial to maintaining supply chain continuity and seamlessness. Hence, businesses have to ensure that the mass production of packaging is at par with the manufacturing of the parts and the items themselves. Furthermore, the design of the packaging parts must be reliably reproduced with no room for errors.

So, how can we achieve this?

The answer is simple - through CNC cutting machines.

The use of a benchtop CNC mill for cutting plastic and foam to produce casing or packaging is not unheard of. In fact, it could be the key to ensuring part safety, especially in transit. Let’s take a look at the role of CNC machines in cutting plastics and foam for packaging.

Why Choose CNC Machines?

CNC machines come with a volley of advantages, some of which are detailed as below:

Higher Production Capacity

Even though all forms of packaging are crucial for securing the article, it might eventually accrue as waste once it serves this purpose. Hence, businesses are often not too keen on investing heavily in the production of such consumables. Fortunately, CNC machines operate autonomously and can continue manufacturing 24/7 without human intervention. As a result, it offers high production capacity with minimal downtime.

Greater Precision and Accuracy

Consider foam inserts, for example. If your part is unable to fit into the insert or the slot is too large for the item, the cutting is effectively useless. To avoid such waste of raw materials, one has to ensure that the production process carries a high degree of precision and accuracy. Fortunately, CNC machines can address this issue through automation and digitization. Such equipment offers low tolerance and bypasses human machinist errors. 

Versatility

CNC machines can achieve more than cutting or designing packaging material. In fact, carving foam or shaping plastics is one of the many ancillary functions of the machine. With the right set of tools and program codes, you can use your CNC machine to cut, carve, shape, punch, mill, drill, turn, etc. other materials like metals and wood as well.

Easier Prototyping

Consider a situation where you are experimenting with packaging for maximum efficiency while occupying minimum space. The process of manually creating prototypes can be quite time-consuming and prone to errors. On the other hand, CNC machines can easily field the issue even if the design is three-dimensional. Plus, the existing code that you may have about your item could be an excellent jumping-off point to inverse the same and create a mirror copy! As such, you can find the perfect design to suit your needs.

Affordable

Through its high-speed, high-accuracy, automatic manufacturing, CNC machines are already cost-effective. However, when you consider other manufacturing formats, like additive manufacturing or injection molding to produce packaging, using a CNC machine works out to be far more financially feasible due to such benefits.

Limitations of CNC Machines

While the use of CNC machines to cut plastic and foam packaging may seem attractive, it does possess a few limitations. These being:

Capital Investment

Despite the advent of cutting-edge technologies like 3D printers, CNC machines continue to remain a hefty investment. And even though the upfront capital investment associated with the purchase of CNC machines is quite considerable, businesses can recover these costs through its wide range of benefits.

Skilled Operator

The skill and expertise of your CNC machine operator are just as crucial as the equipment they run. Hence, depending on your design and machining complexities, you would require a professional who can handle these requirements effortlessly.

Considerations While Cutting Plastic and Foam

Before proceeding with the primary considerations while cutting plastic and foam with CNC machines, it is worth mentioning here that not all CNC machines can function efficiently with the subtractive methodology that is required for packaging. Hence, you first need to satisfy yourself that the machine is compatible with the packaging material you work with, the technique involved, and the field of operation of the router.

With the above foreword in mind, here is a list of few factors:

• Plastics are often used in external packaging. Hence, you can cut them into pallets to create blocks or cubes as a universal shape. These pallets are often reusable and thus offer maximum value and sustainability through their long lifecycle.
• In case you require plastic containers for more specific applications, you can use corrugated plastic as it offers flexibility and durability to accommodate varying sizes and shapes. Apart from cutting, you may also have to water-jet such storage solutions.
• For fragile items, use high-impact plastics to ensure greater safety. To cut such material, you may require a 5-axis CNC machine.
• Ensure that your tool bit is compatible with the hardness of the material, especially while cutting casings and inserts. Incompatible router cutters could result in unclean cuts, which will dilute the use of the packaging.
• For best results, use a multi-purpose machine as it can cut a variety of foam and plastics. It can be particularly helpful when you are unsure about how to cut the material at hand.
• While cutting foam, the combination of collet or quick-release spindle along with tangential or oscillating knife is heaven-sent as they can facilitate most of the actions. Further, use a blower or a vacuum pump to hold the material in place securely.

Final Thoughts

CNC machines allow workshops to create highly detailed packaging for maximum security. Such outputs can also be useful where you intend to reuse the packaging material several times. Hence, the investment in CNC machines is very well worth it.

About the Author:

Peter Jacobs

Peter Jacobs is the Senior Director of Marketing at CNC Masters. He is actively involved in manufacturing processes and regularly contributes his insights for various blogs in CNC machining, 3D printing, rapid tooling, injection moulding, metal casting, and manufacturing in general.