VACUUM FORMING

THE OTHER 3D PRINTING

Vacuum forming is a simple way of shaping plastic into a 3D print. It's a process of taking sheet plastic, heating it up to a pliable state, then stretching it over a hard mold while still hot. Air is then sucked out of the voids around the mold to pull the plastic tightly around the shape. It cools quickly, the mold removed and the result is a plastic shape ready to be trimmed, finished and used.

 

The Vacuum Former might loosely resemble the unit below, but there are many variations for different purposes, sizes and materials. The unit below is a home build DIY design based on the Hobby-Vac, a simple machine that balances both performance and cost.

This is a flip or slide rack version where the plastic is flipped or slid over the heating elements then returned to the forming platen the same way when the plastic is hot enough to mold.

 

 

 

WHAT CAN BE VACUUM FORMED?

Vacuum Forming has a broad spectrum of uses that vary from movie props to dental applications, from candy molds to dimensional signs. In fact you my interact with vacuum molded items every day. It could take the form of packaging or a travel pod on the roof of a car. Remote control car bodies and Halloween costumes are other popular uses. Below are just a handful of examples that show different applications, materials and finishes.

 

 

  

The more I work with vacuum forming the more I realize its potential. I keep pushing the boundaries and find that I can overcome many things that previously seemed out of reach. The strategy in which molds are designed and built largely effect what can be accomplished. I find these problems very gratifying to solve. Note that I'm not trying to make a tool that is meant for one thing to do another, I simply want to realize its potential. Rapid repeatability is key.

The half scale engine facade below is built from formed plastics that encapsulates a store bought 9 quart cooler. The engine is an example of how multiple forms, plastics, finishes, textures and colors can be brought together to create something that would be difficult to do with other output processes. Add to that the economics and rapid repeatability.

 

VACUUM FORMING VS. 3D PRINTING

Q: Why do you Vacuum Form rather than 3D Print?

A: Actually, I use both types of output and emphasize they are not mutually exclusive, each process has advantages and disadvantages. I personally lean more towards Vacuum Forming because it was an economical solution to what I needed at a specific time and the interest just continued. For me it's the appeal of rapid repeatability. Different tools are needed to solve different problems and there is not a one tool solution to 3D output anymore than a one tool solution in your tool box. 

The best case scenario is using both 3D Printing and Vacuum Forming to compliment each other. The Ford model A engine below is my best example of a balance between the two. The manifolds, carburetor, part of the distributor, water pump/hose flange and spark plugs are 3D printed. The bulk of the engine is mostly formed parts except for a couple PVC tubes, those being the oil line, water pump shaft and the alternator.

To sum it up, it just depends on what you're trying to accomplish. For me, It continues to fit my particular needs. In a garage space I'm able to quickly form parts of different plastics, finishes, textures and sizes. I also found its more maker friendly to quickly produce end user products. Below you will see parts that would be challenging for a 3D printer to output rapidly, economically or at all.

 

HOW DOES ONE GET STARTED?

This is one of those good news bad news scenarios. I hope it turns out good news for you. First for the bad news. You cannot easily find quality machines to outright purchase at this point in time (my opinion) unless you go commercial $$$.  It's my belief that this is one of a few reasons why the process is not more popular for personal output.

The best way to start forming is to DIY and build your own to save $ and ensure quality. Quality plays a very important roll in results. This is an easy process to hack poorly and there's no shortage of examples. This is a case of "you get out what you put in". Hacks can get away with light weight plastics often polystyrene or HDPE,  but when you get to thicker more hardy plastics, it becomes more difficult.

The good news is Workshop Publishing makes excellent plans for building a quality machine. I've had pretty good success with them. Doug Walsh the owner of WP has spent many years researching and developing plans that reap professional results at a very reasonable cost. He also publishes a well written book of Vacuum Forming basics that support the plans he sells. This book will give you very accurate information that I highly recommend. It's my bible for vacuum forming.

 

If you can clear the hurdle of building a Vacuum Former of your own, you will be amazed at what you can do with this process. I personally like the ability to come up with a design then immediately make what I design, then more importantly, rapidly repeating it. Vacuum forming offers output that is like no other.

As a product designer, I work with client design constraints all the time and it feeds my soul to realize my own design choices.

It may sound too good to be true but I hope the items in my store will relieve some skepticism of its effectiveness and value. Myself and many fellow Vacuum Formers are surprised this isn't being used more, adding to the other outputs like CNC routing, laser cutting  and yes...3D  printing. They all  work well with  Vacuum Forming.