I came across a method that appears to meet all my needs. The "startup" costs for the starter kit of supplies and the machinery may be a bit high if I had only one item to mark, but if I consider it amortized across all the places where I have lettering needs, the 'per task' price becomes bearable. Further, it allows for text and images at the sizes I want, with solid, un-pixellated lines, in the appropriate colors. It is a system called Decal Pro FX. You can read more about it on the Decal Pro Fx web site Two bits of 'magic' enable this solution - use of mylar film over laser toner images and differential adhesive strength for the transfer paper.
After creating the text or images on a computer, an ordinary laser printer is used on their plastic film paper. Those images and letters are pixellated and not fully saturated/opaque, but are only used to form mylar which is heat-applied over the toner. The result is the letters and images built of mylar with pure solid color. These images are stuck to a transfer paper with just enough force (mainly electrostatic) to keep them in place until they are dry transferred via rubbing to the target surface. A stronger spray adhesive is applied to the bottom of the mylar decal which is what holds it on the final surface.
I ordered the supplies while on a trip and had it all in hand by the time I returned. So far, I have run two tests of the process. It is very promising initially, producing a very high quality solid coloring as the color mylar film is bonded to the laserjet toner ink. That converts the black and uneven texture of the toner image into an absolutely uniform, saturated surface in the exact shape of all the black areas on the paper.
Technique is very important with this method - as many users have posted as they fought their way up the learning curve - and I am still learning how to make this work. Each of the two tests failed in similar ways.
My first problem is in the first pass thru the laminator of my mylar foil and printed paper sandwich, which is mounted on a fiberglas carrier. The foil is folded over the front edge of the fiberglas carrier, it is fed to the laminator rollers, and I am supposed to use my fingers to maintain drag to keep the film from wrinkling. Easier said than done, because it is not a one dimensional tension that is needed. I have to pull back on the foil but also stretch it side to side, letting the rollers pull it from me. I just don't have the finger magic yet, but it will come with time.
Clearly, if the colored foil is not touching the toner ink due to a wrinkle, it won't fuse to that ink - game over for that portion of the image. This bites me again in a later step, when the foil is peeled from the paper leaving the paper with its image now formed of the mylar rather than black toner. Now that the image is on the surface of the paper, we need to transfer it to a clear mylar sheet, to make this into a decal. The clear sheet is folded over the image and this new sandwich goes through the laminator. Wrinkles again.
My second problem is that I am not getting the clear mylar to bond to the mylarized paper image - this is accomplished by an electrostatic bond that is set by the heat of the laminator. The instructions say to rub the mylar briskly to set up the charge, but I am clearly not rubbing it enough or doing something else wrong. The second sandwich comes out of the laminator seemingly good, but when I proceed to remove the paper backing, it all goes awry.
The new sandwich has the mylar images stuck to one side of the mylar film. This has to be a weak adhesion if they are going to rub off cleanly onto the final target location, but mine is too weak. To remove the paper, this sandwich is dunked into water, which causes the paper and mylar film to separate after 1-2 minutes. The lack of sufficient adhesion means that bits of the mylarized image float away, rather than sticking to the clear mylar film. If it had stuck sufficiently, that bit of mylar with the images on one side is my dry transfer decal.
All that needs to be done to complete the process is to dab it dry and apply a careful amount of spray on adhesive to the side with the image. That decal can be put onto some surface - pretty much any kind of material - and rubbed which glues the image to the new surface. Since the spray adhesive is stronger than the electrostatic bond, the clear mylar film will peal away leaving my image stuck where I want it. Or, that is the theory, since I haven't gotten to this point yet. I have no reason to doubt that it works, given all the hobbyists who are using the system successfully.
It just takes an exacting set of steps with technique that is partly learned only by repeated practice. I am going to work on this through the week, up until I leave on another business trip Friday. Once I have good results, I will post some images and go into more detail of how this will be used on one of the more complex fabrication tasks - the plexiglas panel that displays the status of the machine with more than 100 lamps lighting behind it. It has various colored sections as well as clear openings in the shape of the various numerals or characters that each light represents.
1130 Plexiglas status panel |
No comments:
Post a Comment