How are acrylic protractors printed?
How are acrylic protractors printed?
(OP)
I have a design for a measuring device that I may want to have manufactured that is similar to a clear acrylic protractor. The protractors I've handled have slightly raised print or paint on one side that doesn't scratch off easily. What process creates this result? Here is a picture of what I'm referring to.
Thanks!
Link
Thanks!
Link






RE: How are acrylic protractors printed?
RE: How are acrylic protractors printed?
The protractor I'm holding now has no raised areas, just the paint that you can sort of feel by running a fingernail over it. That's what I'm going for.
RE: How are acrylic protractors printed?
I have a protractor almost exactly like the one in the photo. Mine is at least 55 years old. The blue cast suggests polycarbonate, which is often blued slightly to offset a normal yellow cast, but I don't think PC was common that long ago, so I'm guessing a polystyrene alloy.
Polystyrene is cheap, clear and colorless, but brittle. You may remember it from the transparencies in plastic model kits. Nowadays, except for plastic models, you'll probably find styrene alloyed with acrylonitrile (vinyl cyanide) as SAN, or acrylonitrile and butadiene as ABS, or a thousand other things sold under a million names. ... well, almost.
Polysulfone is a little more yellow than polycarbonate, less subject to environmental stress cracking, more temperature resistant, similarly tough and similarly priced.
You might want to visit your local plastic sheet seller to buy a few sheets of various thicknesses and compositions, to get a feel for how stiff you want your product and how difficult it will be to fabricate it from sheet.
I'm guessing your protractor was screen printed (in two steps, one for each color), which requires some care to get good registration. Your screen printer may not like it, but you can specify epoxy ink for durability. Start with whatever ink the printer suggests, and test a few samples yourself.
Mike Halloran
Pembroke Pines, FL, USA
RE: How are acrylic protractors printed?
Mike Halloran
Pembroke Pines, FL, USA
RE: How are acrylic protractors printed?
RE: How are acrylic protractors printed?
RE: How are acrylic protractors printed?
If you're working with sheet, you can wet sand the surface before screening.
You may be able to cover the finished part with a clear semigloss spray, but do some testing to make sure the overcoat doesn't dissolve the screened image or attack the plastic.
Mike Halloran
Pembroke Pines, FL, USA
RE: How are acrylic protractors printed?
RE: How are acrylic protractors printed?
RE: How are acrylic protractors printed?
Cheapo plastic rules, set squares, protractors etc, were made from crystal styrene (transparent) or HIPS (not transparent) which were silk screen printed with a UV-cured ink ( <1 second to cure).
Rules classed as "shatterproof" (rather than unbreakable) were made from K Resin*
Cheers
H
*K Resin is a trade name for styrene butadiene co-polymer (SBC) - other equivalents are available.
www.tynevalleyplastics.co.uk
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RE: How are acrylic protractors printed?
RE: How are acrylic protractors printed?
Keith Cress
kcress - http://www.flaminsystems.com
RE: How are acrylic protractors printed?