Enamel Mug Printing -Problem

[StellaD]

Hi All,

I have previously printed standard Durham mugs which have turned out perfectly, originally on a Ricoh/Sawgrass set up with Trupix paper. With these I dunked them in warm water to cool the mug and the paper fell easily away.

More recently I changed to an Epson with the inks and paper from CityInk Express. Again, the mugs have turned out perfectly but I let them cool naturally (no water).

The nice people at Listawood have sent me a single enamel mug to try and I followed the settings on the BMS site as their mug appears to be the same. This meant pressing at 180c instead of 170c for 140 seconds instead of 170 seconds.

I decided to "dunk" this one in water. The print has come out nicely but the paper had to be teased off in small strips and there are marks on the unprinted areas where the paper has been and also marks from the heat tape.

My first thought was maybe the different paper doesn't like being put in water but that doesn't explain the heat tape marks.

I really like the mugs but wonder if anyone has any comments/advice before I invest in a batch. I don't think they are saleable as they are.

TIA

Stella

[Listawood]

Hello Stella, For our Enamel mugs we would recommend cooking at 200c for 45-60 seconds (or 190c for 40 seconds if you have our Genie III Mug press). At the end of the cooking cycle remove the paper and cool in front of a desktop fan rather than dunking the mugs in to water. If you need another sample to test or if you require any further assistance then please do not hesitate to contact me on tradesupplies@listawood.com and we will be pleased to help you. Many thanks, Kris.

[Andrew]

When you find the paper starting to stick to a blank that is mostly to much heat getting to the coating. When this happens the coating softens and fibres of the paper start to bond into the coating and get stuck when cooled. As Kris mentioned, reduction on time is needed. Depends on your set-up it might take a bit of fiddling with settings. We tend to use 195 for around 70 secs. Metal conducts heat far quicker than ceramic so needs less.

[StellaD]

Thank you both for your replies - really useful and the paper eating into the coating seems to be exactly what has happened. Clearly I need to reduce times!

Kris - I am sending you a mail!

[UK Printed Mugs]

I certainly would question the temps and times from Listawood as we use their enamel mugs but find that they are only perfect at 170c and 180s (using Adkins Mug Press). Too much heat and the paper burns. We do use a desktop fan though and not water with these.

[GoonerGary]

Your ink paper set up will determine times, but my enamel mugs are 167c and 155s on a Magic Touch Arc press.

[Andrew]

As you can see above, you are probably going to need quite a few samples rather than 1 as you need to find what is right for your set-up. If you start off with less time but make sure the transfer is taped on very well, you can take a peak at the print after initial time to see if it looks like a good print then give it a bit more time if not. Certainly not a perfect way to get there but might not waste as many mugs and gives you a better idea for the second mug to trial.

[logobear]

we print enamel at same settings as regular mugs and seem fine.
We do need to bulk out the rest of the clamp thou.
The rim has to stick out the edge, so we use a second mug bottom in to keep the pressure even

[StellaD]

Thanks for the extra replies.

Listawood have been very helpful in explaining that their coating differs to that used by others so their pressing heats and times are different also. More mugs arrive tomorrow (Friday) so I will experiment, starting with their suggestions and go from there.

Will let you know the results soon!

[StellaD]

Problem sorted!

Listawood kindly sent me further samples and I went with their settings of 190c for 40 seconds and air cooled.

A perfect print with no paper delamination first time.

I accept that other people are using very different timings and getting what works for them but for Listawood enamels the much shorter time seems to be the answer.