3D Printing Vs Vacuum Forming: Which is more efficient?

The 20th century was, arguably, the century of mass technological changes. The 21st century is shaping up to be the century of mass technological improvements. As such, it will rely heavily on modern production techniques such as 3D printing and vacuum-forming. Both of these can offer significant efficiency gains over traditional manufacturing processes. 

To explain further, Nick Mills, General Manager of Ansini shares his insights into the efficiency of 3D printing and vacuum forming. 

3D-printing and vacuum forming compared

3D printing is more formally known as additive manufacturing. In this approach, layers are cut individually and stacked on top of each other until the item is produced. Vacuum forming, by contrast, is a thermoforming process. In this approach, a base material, usually plastic, is pulled into a mould by means of a vacuum. 

Both 3D printing and vacuum forming are more agile than traditional manufacturing processes. They also have fairly low resource demands. As such, both processes can be considered highly efficient. 
This means that choosing one method over the other largely depends on your goals. In other words, which particular aspect of efficiency is most important to you?  With that in mind, here is a quick guide to how 3D printing and vacuum forming compare in certain, key areas. 

Minimising waste

In principle, vacuum forming probably has the edge here. The reason for this is that it works using moulds. These moulds can be designed to minimise waste. For example, they could ensure that there was little to no excess material needing to be trimmed off. 

In practice, the trimmings from both 3D printing and vacuum forming can usually be recycled. For example, aerospace plastic manufacturers now often use trimmings from these processes to create aeroplane cabling systems. Regular passenger planes can have 100-200 miles of cabling inside them. 

Other kinds of manufacturers are following suit. In fact, using offcuts for cabling is becoming increasingly popular. This is hardly surprising given that electrical devices rely on them, as does the internet. 

Minimising cost

Objectively, on a like-for-like basis, the costs of 3D printing tend to be higher than the costs of vacuum forming. This is mainly because 3D printing is a much more complex process. The caveat to this, however, is that it’s extremely difficult to make like-for-like comparisons between 3D printing and vacuum forming. In the real world, they tend to be used for very different applications. 

As a rule of thumb, if it is possible to use vacuum forming to produce an item, then this will generally be the lower-cost option. The exception to this is for very small production runs. With these, using vacuum forming requires extra time and money to set up the mould. This often gives 3D printing the edge. 

On the other hand, 3D printing can be used for applications that would be well beyond the capabilities of vacuum forming. In these situations, it would be more appropriate to compare 3D printing to traditional manufacturing processes. Generally, 3D printing comes out as the clear winner here. 

Firstly, it usually reduces the costs of manufacturing, often quite significantly. Secondly, it can allow plastics to be used in place of traditional materials such as metals. This can substantially reduce the weight of the product. It, therefore, reduces the item’s drain on the aircraft’s fuel. 

Maximising speed 

The issue of whether 3D printing is faster than vacuum forming or vice versa largely depends on your point of view. If you only want to create a small batch of items, then 3D printing is likely to have the edge. This is particularly true if the items are complex. 

The main reason for this is that 3D printing does not require there to be a mould. You, therefore, save the time needed to create the mould. As production volumes increase, however, the initial time needed to create the mould becomes less of an issue. Eventually, there comes a tipping point when it becomes more time-efficient to create a mould. At this point, thermoforming becomes the faster process. 

How quickly this tipping point is reached generally depends on how complex the item is. For example, aircraft seat manufacturers are highly unlikely to use 3D printing for their goods because they are relatively basic. It’s therefore fairly easy to reach the sort of production levels needed to justify creating a mould and, hence, vacuum forming.

As the complexity of an item goes up, however, so does the size of the production run needed to justify the use of a mould and hence vacuum forming. In fact, very complex items may not be suitable for vacuum forming. They may be suitable for other approaches to thermoforming such as pressure forming or injection moulding. Alternatively, they may require the use of another manufacturing process, such as 3D printing.

Handling complexity

When it comes to handling complexity, 3D printing is clearly well ahead of vacuum forming. For example, aerospace plastic manufacturers often use 3D printing for key aircraft fixtures such as jigs, gauges, and templates. 3D printing has even been used to produce a whole engine (albeit under laboratory conditions).

Vacuum forming, by contrast, is more commonly used for relatively simple, interior components. Aircraft seat manufacturers routinely use vacuum forming to produce aircraft seat mouldings. These can include headrest, armrest, footrest, and table assemblies. 

Theoretically, it is possible that vacuum forming will improve so that it can handle more complex designs. In practice, however, it seems unlikely that it will improve to any great extent. Fundamentally, vacuum forming is a very simple process. As such, it has relatively little obvious room for improvement. 

Boosting innovation 

Realistically, there is no contest here. It’s probably no exaggeration to say that 3D printing is one of the most exciting developments of all time. 3D printing allows for rapid and cost-effective prototyping. It, therefore, works perfectly with modern approaches to design and production. 

One of its particularly useful features is that it can be used to lay the ground for other forms of production. For example, aerospace plastic manufacturers can use 3D printing to create prototypes of items they intend to produce by other means, e.g., vacuum forming. 

They may very well use 3D printing to create the initial run of production moulds for when the item moves into the later stages of testing. At present, it’s unlikely that 3D printing would be used for the final production moulds. This could, however, potentially happen in the future.