Old thread, I actually ended up attending the Plastics society conference last year and saw the vendor who is doing the robotic 3D printing directly with the head. That’s actually not a sublimation process, its a digital printing process that actually builds up material directly on the surface. There is a vendor in the US who provided me with some samples, and it is nice that you can print directly on the part but are limited with the depth of the part. (IE a flat or nearly flat surface only about 3mm deep, past that the droplets of ink spread too large to be useful). Because it’s using the same technology as an inkjet printer, you could change the image for every print as long as it was tied to the path of the robot. The tool he sticks the hat in is just a jig so the robot can precisely register the hat. If it were off even slightly then you’d have registration issues.
It’s a great process if you make products that your customers all want to have their logo on, but the setup is quite high. A sticker or pad print is obviously a lot less work, but it makes it difficult to get the minimum order quantities. In that case that kind of setup makes sense when you have high volumes (a ton of hats) but low MOQ’s (only 15 for Bob’s lumber depot).
The robotic arm gets around that by allowing the head to print directly on a small area of curvature at any given time, then it’s cured and moved on.
There are other vendors out there with sublimation products but it requires your parts be made of the right material, usually a polyester based process. Most normal PC/ABS and other materials can’t sustain the high temperatures used during the thermoforming process.
During the thermo forming, the ink particles on the die sub film turn to gas and embed themselves into the polyester material.