Mug Help - Ghosting Black Text on Polymer Mugs

[liannef]

Hi
I am having problems with black text keep ghosting on polymer mugs. I've done the same design on ceramic with no problems and have done other polymer mugs with no problems and saying that actually some had black names on! I've tried reducing pressure, increasing pressure and taping really tight and I tape down the sides of the handle anyway and don't know what I'm doing wrong. I take the puck out and take the paper off really quickly but still does it and it's only the black text on one side of the mug, the other side has a graphic and is fine. I have an adkins press and haven't used it that much but haven't had any real problems till now. Any ideas?
Thanks
Lianne

[FutureProject]

do you dunk in water? it sounds like what I get when using crisp black text on the ceramic mugs I get which is stopped by dunking / reducing the temperature quicker after pressing.

[rossdv8]

Poly Mugs don;t need to be dunked. They cool much faster than ceramic. Ghosting might be just too much pressure in the press. Poly Mugs don;t need a lot of pressure. Too much and the colours ghost. Too little and they are not vibrant. Once I find the sweet spot for a new brand of mugs I make a pressure shim.

[liannef]

Hi, I'm having problems again with the polymer mugs, they still seem to ghost on the side closest to me in the press so tried reducing the press a lot thinking that maybe it was moving the paper when closing, also tried increasing it a lot and neither makes any real difference. Full bleed designs seem to work ok or maybe the ghosting isn't as noticeable? it's the designs with a lot of white space around them that are worse and especially ones with more black. Anyone else do polymer mugs and have an adkins press? I'm doing 190 for 90 secs and have tried 190 for 85 secs. Ceramic mugs seem to work fine so don't understand why I'm having such a hard time with the plastic ones. Any ideas would be much appreciated. Thanks Lianne

[rossdv8]

Hi llannef,

I've not done any poly mugs with large solid black text, so I have no idea if big black letters would be ghosting on my jobs.

But my small black and solid blues are ok I think. I use a cheap Chinese press for the polymer mugs. The ones you see all over ebay with the horizontal heating element and the handle like the handle of a garden spade. I use the cheap Chinese mugs because we didn;t have a distributor with stocks of poly mugs in this country when I started doing them.

I can;t help with the Adkins But for what its worth this is from the cheapo press. The Adkins will have completely different settings.

So what I've given you is my settings for Ceramic and Polymer on the off chance you might find a similar difference between the two on the Adkins.
I can say however that the settings on the instruction sheet forthe press were way, way off and I ruined a heap of mugs trying to press to them.

My press has settings for a a Dwell temperature, a Temperature to Press at, and a Timer. It is in FAHRENHEIT.

My Ceramic mugs are pressed at: Dwell - 230 Press - 345 Time - 140

The mugs in the pics were pressed at: Dwell - 300 deg Press - 330 deg Time - 120 sec

The thing that took me longest to work out was ghosting images. IU ended up using a much lighter pressure than I stared with.
Before pressing there is 15mm of the puck sticking out the top of the mug
The mug will deform a little, due to heat and pressure.

After pressing, and once the mug is COLD, if I slip the puck in, using its own weight to slide in until it stops, there is 34mm between the top of the mug and the end of the puck.

I hope that makes sense. I can't think of any other way to gauge the amount of pressure. It might give you some ideas to play with.


The images are not as good as I hoped. Zooming in with a cheap camera But the edges of the text in reality are pretty crisp. The blue has no fading and is consistent across the whole text. The black is 'very' black.

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300 330 120

[liannef]

Hi Rossdv8, thanks for your help, I've reduced the temp a lot and that seems to have sorted the ghosting but it's now not a solid colour, it looks like someone has dabbed it and removed ink or looks cloudy. Any ideas if this is to do with pressure or is the temp too low now do you think? Thanks Lianne

[rossdv8]

Hi Lianne. I think perhaps you might need to play with the pressure and time. There's really not much you can do once you get the temperature right, other than adjust the pressure and time.

As I mentioned I found the instructions with the press were so far out of reality it too ages to work out where I was going wrong. I am lucky. I started this as a hobby initially, so I expected to 'spend' a considerable amount of money, just as I would if I was doing any other kind of non profit hobby or sport. Once I more or less perfected the technique, and all my friends were happily drinking out of, or wearing, my rejects, I started making some of my stuff available for sale.

Doing it as a hobby until you get it perfected is the only way I can see for justifying wasting materials on failures. But I'm sure, like me, you will be able to offload the slightly imperfect mugs onto people around you.

Try putting a poly mug in the press cold, with a couple of pieces of paper wrapped around it to simulate the print and the protective wrap, then do up the adjustment until it is only just too tight to turn the mug using the handle. Start with that, then do one set for the time and temp you got nice blacks, then another for maybe 20 seconds longer. Then let everything cool again and put the mug back in the cool press and tighten it a bit more, so you can;t move turn the mug, but not tight enough to squash it.

Then do the same temperature and time as you did to get good blacks, and again for 20 sec longer.

And if you are still getting blotchy solids, try reducing the time by 10 seconds LESS than what gave you a good black, again at both pressures.

[rossdv8]

Hi Lianne. I think perhaps you might need to play with the pressure and time. There's really not much you can do once you get the temperature right, other than adjust the pressure and time.

As I mentioned I found the instructions with the press were so far out of reality it too ages to work out where I was going wrong. I am lucky. I started this as a hobby initially, so I expected to 'spend' a considerable amount of money, just as I would if I was doing any other kind of non profit hobby or sport. Once I more or less perfected the technique, and all my friends were happily drinking out of, or wearing, my rejects, I started making some of my stuff available for sale.

Doing it as a hobby until you get it perfected is the only way I can see for justifying wasting materials on failures. But I'm sure, like me, you will be able to offload the slightly imperfect mugs onto people around you.

Try putting a poly mug in the press cold, with a couple of pieces of paper wrapped around it to simulate the print and the protective wrap, then do up the adjustment until it is only just too tight to turn the mug using the handle. Start with that, then do one set for the time and temp you got nice blacks, then another for maybe 20 seconds longer. Then let everything cool again and put the mug back in the cool press and tighten it a bit more, so you can;t move turn the mug, but not tight enough to squash it.

Then do the same temperature and time as you did to get good blacks, and again for 20 sec longer.

And if you are still getting blotchy solids, try reducing the time by 10 seconds LESS than what gave you a good black, again at both pressures.

Some other people might be able to give you better advice. I've only been doing polymer mugs since about 2012 or 2013, so I am still not an expert