Polymer mugs decide to melt!!!!

[JMugs]

Don't print them often, but have the times and temps in my little black book. So print first one 190 degrees 90 secs lovely. Fire up the other presses and off we go....they melt on the edges!!!! 4 wasted as I run 4 presses. Much fannying about and 4 more gash mugs and I end up with good prints at 170 degrees and 120 secs. I only wanted 12!!!

So this raises the question of what times do others use for polymer mugs?

Customer gives me about £300 of business a month every month so a Saturday night call for Sunday 8am is worth it as he normally wants things next weekend.

[ArferMo]

140 seconds at 180ºC

[pisquee]

my little black book... and off we go...fanny ... gash

something on your mind?!

[rossdv8]

300F 330F 120s

Obviously my press uses dwell, hence the 3 settings.

I print mostly polymer mugs and have the best results with that setting. But don't make the pressure really tight like you would for a ceramic mug or you lose definition.
If you don;t have a profile for polysub mugs, the one for white t-shits probably works as well, although I suspect you have a profile for just about everything

[JMugs]

Strange old world then
So my old figure was 190 degrees
Arfermo 180 degrees
My new figure 170 degrees
Rossdv8 165 degrees

Time wise 90 seconds to 140 seconds.....pick the bones out of that lot!

[ArferMo]

Just goes to show how inaccurate thermostats are and also the power of the heat element in getting the article up to temp.

[rossdv8]

And a good reason to test print occasionally.

The instructions with the press I'm using now say something like 40 seconds!

I was using an expensive mug press but was getting fading at the bottom of ceramic mugs. So I got a cheap Chinese press to preheat the mugs. Turned out the cheapo gave me brilliant results as long as I didn;t use ebay mugs. But something as simple as changing the hunting elephant means the temp can change by up to 5 degrees Fahrandwide. I don;t notice a big change with temp variations of up to 5 deg Celsius or 10 degrees F on Poly, but I do on Ceramic.

So now the expensive press is relegated to pre-warming ceramic mugs Just enough that they can still be handled comfortably with bears hands.

I test print occasionally and update my settings if there's a major change. They are written on card and taped to the presses. Pressure is controlled by aluminium shims. There are images on DSF somewhere. Just a piece of thin aluminium with a 'U' at each end. The end for Poly Mugs is wider than the end for Ceramic. The thing sits over the thred where the adjusting knob turns into the steel tube. So a mug swap means just flipping the shim and adjusting the knob until it just touches.

BUT. There's always my but. When I've got ceramic mugs from a different supplier, I sometimes had to make a new shim. So I get a feel for the pressure on the old mug, then put the new one in and try for the same feel. Press a few and adjust if I need to. This might seem off topic, but I'm back on when I add that I recently got some Poly Mugs that I didn;t import from Sun Fly. And they were a different diameter! Only slightly, but different enough to measure with a Vernier caliper. Add different enough that the first mug was banding. So I had to make a shim just a tiny bit different in width.

[Quinsfan]

But something as simple as changing the hunting elephant means the temp can change by up to 5 degrees Fahrandwide.

I am guessing the Fahrandwide is Fahrenheit but what is " hunting elephant"? :biggrin:

[rossdv8]

Sorry, my warped humour has been absent from the forum for too long. "Heating Element"

That reminds me that I still haven't posted the promised pics of using my balls to hold teflon sheets on my flat presses.
I can't find the thread about using teflon sheets on presses so I'll post it here anyway.
I don;t use my balls any more. I got some thin neodymium strip magnets. The neodymium balls were just the only strong magnets I had back then.
The strips work better on my big INSTA press.

Just saves putting a teflon sheet in place each time. On the bottom platen I just wrap the teflon under the rubber mat. Except the INSTA, where I keep it in place with drawing pins thorugh the sides of the mat.

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Ok, so back on MUGS !

I do the same on my mug presses. Instead of using a piece of paper to prevent bleed through to the element, I use magnets to hold a teflon sheet in place. Easily removed for occasional cleaning, but never seems to need it.

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[JMugs]

Magnets are a nice simple idea.