Eieio,
Your assumption is correct. The paper is used as the vessel to transfer the dye type ink, from the inkjet style printer (can be done with laser as well with different setup). The dye type ink is actually a solid that goes through the inkjet printer. The ink is unique in that when heated it does not go through the normal phases of matter. Solid, Liquid, Gas. As with water, starts in solid form as ice, then when heated goes to liquid form, water; then with the continuation of heat goes to steam, thus passing all three phases of matter. This special formulated dye does not go through the liquid state. It starts off as a solid, ink on the page, then when the heat is applied, and the dye gets to about 400?F, the solid dye goes from solid to a gas. And as we know gas takes more volume/space than a solid. With this matter change to a gas, the dye expands which requires more space from its original solid state of matter. Just like ice to water, to steam.
The substrate, in this case the FRP or AL disks, are all coated with a thin film of polyester which has its own unique properties. At about 380?F the polyester will open up (release its surface tension) and start to expand. This now produces space from the very tight bonds of the cool polyester.
What happens then with the use of the heated press is that the expanding gas from the dye has nowhere to go but into the opening/expansion of the polyester. The gas dye then fills the voids of the expanding polyester. The pressure is what keeps the gas in the direction of the expanding polyester. The gas dye then attaches itself to the polyester and fills the voids produced by the heated and expanding polyester. This takes approximately 30 seconds up to 20 minutes depending on the substrate. Not to confuse you more, but for example, felt book markers take only about 30 seconds to complete the process because the felt is very loose material to start with, whereas, a ceramic mug which is much thicker and denser requires about 5:30 to complete in a mug press. In a convection oven with a pressure band can take up to 20 minutes. So depending on the method used, the time varies. I have a mug press which concentrates the heat in a small area and applies the presser directly to the mug much better than the convection oven/pressure band system does. But I also have dog dishes which will not fit in the specialized mug press so the convection oven and pressure band is the only way to complete the transfer. But I digress...
To answer the question of the paper, yes the paper is held in place by special heat tape. It is aligned with the edges of the base plate (MDF in the suppliers special made template/holder). The whole assembly with the taped down transfer paper is then put in to the press and the process begins.
Your Question:
In your image, you show the 0.030" disks sitting above the 0.010" plate (similar to the image for the FRP). Aren't the disks supposed to be down in the holes in the plate?
A: Yes the AL disks are about .020" above the .010 plate. Sorry the drawing was not that clear. The bottom of the AL disk and the plate all rest on the same surface which would be zero. Then the .010 plate would cover 1/3 of the .030 disk allowing the upper 2/3 of the disk to be exposed so the transfer paper sits on top of the disks. The .020 space is used to help prevent heat transfer and heat loss from the .010 plate, to make the transfer complete correctly.
Q: You asked for holes in the plate that are 1.010" diameter. Would it matter if the holes were square rather than round, so long as they held the disk in a fixed location?
A: No it does not matter at all. The purpose of the tray/holder is just to hold the disks in place while the process is completed. Does not matter the shape as long as the disk is held to very small tolerance to minimize movement.
Q: The 0.010" thickness would pretty much eliminate anything other than metal - Al, Brass, or steel - for the alignment plate as designed.
A: That is what I think too..but you present an interesting thought...
Q: But could you instead use a 1" Fostner bit to cut a 0.010" or so deep round impression into a thicker piece of high temp fiberglass (or maybe a plate of your FRP) as the register?
A: The FRP is very unstable when heated and after going through a heat cycle or two I think the FRP would warp too much to be of any use. Additionally the FRP, from my supplier, in a maximum of 1/8". Way too thin to be used as a base for any length of time.
Q: Maybe put a smaller hole (1/4"?) through the center of the impression so you can poke the disks out after the ink has set?
A: GREAT idea !!
Q: You didn't give center-to-center dimensions on the 1" holes. How accurate must those dimension be held?
A: The drawing is what I would like to do. I can make my printing template to match what the end result of the jig is if needed. Make the small corrections in the printing template once the jig if finalized and use the adjusted printing template from that point on. The spacing between centers would be 1.135". 1.01 for the hole and .125 for spacing between holes, right?
Q: Would the Fostner bit in FRP work for alignment? Can you live with the manual alignment possible by the 1st method?
A: A Fostner bit in some high heat resistant wood could work. But the FRP would not. Absorbes heat too much and would warp after only a couple uses. That is why I am looking at metal. I think it would withstand the heat better.
And now you have me thinking another direction too...Find someone that can take a piece of .030 metal, and cut out .010 from the metal as I need to put the disks in to. But then back to finding a good metal worker too.
I am leaving my house now, and not sure when you will get this but if you would like to talk via phone, to help understand what I am missing that would be fine with me. My number is: 510.701.3311 -Scott
