"Necessity is the mother of innovation." This is certainly true on many a factory floor where creative minds develop new solutions to problems large and small every day. In the world of thermoforming, toolmakers and processors have proven themselves capable of solving myriad challenges through both complex engineering and plain old line-level tinkering.
At CMT, we've had too many conversations to count about weird ways to use HYTAC syntactic foam to improve thermoforming. Still, we thought it would be interesting to provide a short list that might spark some new ideas (or re-live some horror stories) among our customers.
1. Die locators: When forming PP on roll-fed machines, many processors will use floating cavities with die-locating pins on the trim station. This is done to accomodate the shrinking associated with PP. The dies are able to 'locate' the formed part through the use of syntactic foam locators attached to the steel rule. Usually a tough material like XTL is best suited to this mini-application.
2. Ring assist: Keeping heat in the sheet is a major challenge when the hot plastic comes into contact with oher materials such as aluminum. If the sheet is 'chilled off', it can leave marks on the final part. Using syntactic foam around the edges of the clamping frame helps reduce this chilling affect and ensures that heat stays in the sheet.
3. Sag table: When a hot plastic sheet is being indexed into the forming station, certain materials have a tendency to sag, e.g. polypropylene. Over the years, new optical sensing technology (sometimes referred to as a sag detection system) can alert the operator while the ovens automatically retract in order to avoid burning. Several users have chose to build small 'sag tables' with syntactic foam allowing the material to continue through the pin chain and indexing system without losing heat.
4. Female plugs: We're not going to get into the male vs. female tool debate in this post, but the majority of plug assists are used with female cavity tooling. However, several applications lend themselves very nicely to a 'female plug' where the syntactic foam is designed in such a way to provide a frame or box that matches up with the male plug. The female plug comes down and around the sheet as it's being formed, providing stability and (again) ensuring that the heat stays in the sheet.
5. Insulator plates: It is often desirable to keep process heat away from process equipment, most specifically around molds and platens. Syntactic foam is superior to almost all composite materials in its ability to insulate. It is easily cut or shaped to fit in a variety of configurations and it offers long-term temperature stability.
Have you used HYTAC (or other materials) in these ways? Let us know what creative uses you have developed to improve your forming process.