Mug Printing problem - image fading

[Justin]

OK, raised temp to 205c and time to 195 secs. Printed another 6 mugs and they look fine. Next mug out has similar problem but you can actually see the shape of the element in the photograph! I guess this could be an element problem. Very bad timing, why is it always when you have a decent size order that has to be out quickly?!

[Justin]

Another kick in the teeth. A friend lent me a brand new 4 in 1 press to help get the mug order out.....it has 2 mug elements, one for an 11oz mug and the other for much smaller....neither will work with my 10oz mugs!
Never been a fan of these presses but was looking forward to having a go.

[bms]

neither will work with my 10oz mugs

Don't follow why this would be the case - both 11oz mugs and 10oz mugs, normally, are 80mm in diameter so an "11oz" blanket (which is another name for the standard mug blanket) will print a variety of mugs which are around 80mm in diameter.

How are you pressing the mugs Justin - putting a mug in when the display is reading 180 degrees, or whatever you have the heat set to (after taking out a printed mug)? If some are printing fine and then you get a rogue one then this is strange, especially with the lines showing as per the image. Do you have a sheet of the silicon wrap available - the red rubberised material? You could wrap the mug with this before putting it into the press and this will help to spread the heat more evenly over the mug surface.

[Justin]

The combo press doesn't adjust enough to be suffucuently tight for 10oz mugs.

I wait for the press to reach full temp beforte putting mugs in. All mugs are coming out the same now with the lines. Don't have any silicon wrap or I could use it in the combo press.

Just reduced the pressure down a fair bit and tried another, print came out ok but definate element shape lines showing.

[bms]

wait for the press to reach full temp beforte putting mugs in

When heating up any mug press that goes all the way to 180-200 degrees you really ought to put a mug in the press (one which you re-use continuously for this purpose). This ensures the blanket doesn't get overly hot during the warm up process (and potentially burn out). Once the press has reached 180 degrees with the mug in place then remove it and put in your mug for printing - the temp will drop and then gradually heat up again.

The original mug should be put back in the press during cool down as well as warm up. Doesn't help solve this problem necessarily but helps to prolong the life of a blanket.

The element in a the mug press is a continuous loop - the power leads go in and come out at the same point, so the blanket should work (through a continuous feed of heating element - a bit like a warming blanket for beds, but much more tightly woven) or not work at all if the element is broken. Do you have an infra red thermometer to test the temp of the blanket at different points?

[Justin]

Yes, I always put a plain mug in during warm up and inbetween presses, sorry I must have missunderstood your question.

I tested it last week with a therm. And it was fine, will have to try it again.

[Justin]

The element's definitely working but I'll check the temp. all round. As I mentioned, the outline of the element is imprinting onto the image similar to an old kettle element shape so it's certainly working!

[Justin]

Quick update on this problem.

Temp. checked on heat blanket, all seemed pretty much ok. New blanket fitted anyway, made no difference. Tried 2 different brands of paper, different temps/pressures/height in the press/time and so on. Nothing stopped the problem. Tried a different mug supplier and hey presto, the problem dissapears, 36 mugs printed perfectly. Went back to other suppliers mugs and problem immediately transpires. Went back and forth just to make sure.

Been in touch with supplier regarding what I assume must be faulty mugs or at least a fault in the coating. I've had to send them printed and unprinted mugs form the same batch along with printed/unprinted papers from 2 suppliers. They're now carrying out their own tests!

Will update when I hear back from them.

[Andrew]

That's a strange problem to figure out on the mugs. If they do print but show the heat element lines and the others print fine then it sounds like heat dispersal problem or the coating scorching slightly under direst heat. Sounds a fun problem for someone to work out.

[Justin]

Fun problem that's cost me a fair whack in wasted time and materials! lol.