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Sometimes it can be hard to know whether it is better to approach a project from the front or the rear. Or maybe you can find a new shortcut or route to work. While on a recent trip we were navigating in an area we hadn’t visited in several years and the city had been in a constant period of growth and expansion. Things were vaguely familiar but clearly not providing us a clear and distinct view of exactly which way we had traveled before. However, I used a descriptive approach to satisfy my traveling companion’s exasperation. Simply stated, all roads lead to our destinations if we combine the right number of turns along the way.

It certainly is true that there are many ways to skin a cat, as the familiar statement suggests, and so it is in our craft. When asked to provide this article on the subject of “when to thermoform or not,” I was sure there would be many disputable arguments on the subject and all I have to support my remarks are the experiences of my past and what I have learned from my successes and failures with the thermoforming process. I need to clearly point out that I have never explored all the possibilities or prospects, but have simply built on what I and others have found effective and have learned from those experiences.

Having provided a reference point, let’s jump in. What makes one approach to any project better or more appropriate than another has to be the result being sought. If it is the fastest and least expensive, if it requires a substantial investment in equipment or maybe almost none at all, and then add to that foreknowledge, all are subjective avenues that have to be considered. Anyone have an optimizing program? What are the basic criteria that have to be supplied to start any optimization? The method, how do you want the project processed, least material waste, least labor expense, is the material directional or nondirectional, smallest parts size allowed, largest parts range . . . all these critical issues will determine the best answer, which very likely could and would all be different.

I have read some of the different forums on the subject of thermoforming and have heard of disappointments and failures as well as a relative number of adventures that have produced reasonable results. Bank all that knowledge and pledge it against your future approach to the subject. So, when should I thermoform a project or build it with ordinary stack applications? Let’s establish how or what elements are available for your best successes. What type of heating sources do you have at your disposal? Do you have an oven built for the processing of solid surface, which is built with top and bottom elements and a convection capacity for very even temperature control? Or perhaps a thermoplatens press specifically designed and built to transfer the exact and most direct energy into the material in the shortest and most even means established? These two primary energy sources will be one of the main barriers of entry into this field of production and one will hold advantage over the other.

The materials are undisputedly expensive and the prospect of failure and disappointment can only be made more painful with the financial losses that are contributed by lost materials. Overheating, underheating and uneven heating are all major contributors to basic failure and the need for repeatability. If the project requires larger size parts, then understand, too, that handling the heated parts will require additional fixtures and handling equipment to transfer the large dangerously hot (roughly 340 F) material while now in a rubberized format. When brought into contact with human flesh, burns occur instantly and are a very real and serious safety consideration.

My suggestion, start with small parts and learn how difficult the parts are to handle in a different physical state than you are familiar with. Once the original shape has been altered and the sheet is no longer flat it cannot be returned to the platen heater for reheating. Yes, reheating is very possible and should be explored especially when you cannot get the part to the fixture or mold in time to make the component conform to the mold or shape required. Every time speed and a rehearsal of transfer are an important consideration and should be calculated carefully. Sometimes preheating of the mold must be done in facilitating the application correctly. The best means then to reheat is an oven with a mouth receiver larger than the material shape after the part has cooled in an incorrect form. Reheating then can be accomplished; the materials, if not damaged in the failed process, are subject to another attempt. What kind of damage? Tears, whiteout or fracturing are some of the issues that will deem the material expended from this fabricator’s view.