As promised during last week’s blog posting, we are talking some more about thermoforming tools produced by 3D printing.
A 3D printed thermoforming tool can take advantage of Stratasys build style to build in the vacuum channel and eliminate the need to drill out pin holes and vacuum feed areas for tooling. So you have the option of building in several ways to make the tool. Each way has some advantages but each is going to be different.
If the part needs to be fairly smooth on both the outside and inside of the shape, using a solid surface with a more traditional hole pattern where the material is drawn down by the vacuum until the tool may be the best bet. The part build style can be modified to have a spare build interior to maximize the draw (vacuum sucking the plastic sheet against the mold) while keeping the traditional solid surface. The holes can be built in by the use of the CAD program to the surface so that the need for post build finishing and drilling is minimized.
For addition, modification of the surface and fine tuning the vacuum, (as an example for areas where the sheet is difficult to be drawn into a crevice feature) the area can feature more holes in the solid surface walls. In some cases, the tool can be built with no skin so that the sheet draws down onto the open lattice surface where the part is open. This technique Is particularly useful when using a vacuum table for a quick prototype of the shape or for thin gauge applications for food packaging. The ability to pull the vacuum can be modified by using different sparse build styles and in some cases having an internal channel for vacuum channeling. There are many academic papers regarding the design of 3D printed vacuum forming tools, numerous white papers and technical bulletins that speak to design and “how to” tips when developing these tools.
Whether the choices are to create the tool with a solid surface and designed in holes, use sparse build on the interior, have a built vacuum manifold in the bottom of the tool, or to do a simple shell with holes, the possibilities of using 3D printing is endless in this application area. A couple of notes of caution, food packaging including clamshell disposable containers that are thin guage thermoforming may be subject to FDA registration rules. When In doubt on whether your application should be registered with FDA such as blister packs, thin gauge thermoforming, disposable food containers, or cosmetic packaging, always consults with experts on packaging regulations.
In general, thermoplastics sheet used for thermoforming can be used with any of the tools printed from the filaments that come from the Stratasys standard stock. For even more detail and glass smooth surfaces, PolyJet tools can be used with build in vacuum channels and pin holes.
For more information about thermoforming and how 3D printing can improve your bottom line, contact Engatech at firstname.lastname@example.org or call our offices at 866-499-7500.