Water transfer printing activator ideas

[japcarmaniac]

hi, I am from scotland uk and have little chemistry knowledge so i hope I've posted in the right section to start lol.

as in the uk I am finding it difficult to get activator for water transfer printing. there a few formulas that can be mixed up by myself but id rather be able to understand why these chemicals are needed and perhaps be able to make my own. for those who are unaware water transfer printing is basicly a sheet of PVA with an image printed on one side. this film is placed in warm water and an ACTIVATOR is sprayed over it to dissolve the PVA and leave behind the ink and its adhesive so that an object can be placed into it and coated in the image.

so at a glance i need to be able to dissolve the PVA. I've looked at many formulas and the most popular chemicals i can see in them are

xylene
isobutanol
mek
ethyl acetate
butoxyethanol

what i do know is that my chemicals would need to be non soluble in water. I've seen the msds iof an activator sold in aerosol form and its 70% butoxyethanol. i have no idea what the other 30% could be.

any help would be most appreciated and i hope to learn a thing or two.

thanks in advance

derek

 

[chemisttree]

hi, I am from scotland uk and have little chemistry knowledge so i hope I've posted in the right section to start lol.

as in the uk I am finding it difficult to get activator for water transfer printing. there a few formulas that can be mixed up by myself but id rather be able to understand why these chemicals are needed and perhaps be able to make my own. for those who are unaware water transfer printing is basicly a sheet of PVA with an image printed on one side. this film is placed in warm water and an ACTIVATOR is sprayed over it to dissolve the PVA and leave behind the ink and its adhesive so that an object can be placed into it and coated in the image.

so at a glance i need to be able to dissolve the PVA. I've looked at many formulas and the most popular chemicals i can see in them are

xylene
isobutanol
mek
ethyl acetate
butoxyethanol

what i do know is that my chemicals would need to be non soluble in water. I've seen the msds iof an activator sold in aerosol form and its 70% butoxyethanol. i have no idea what the other 30% could be.

any help would be most appreciated and i hope to learn a thing or two.

thanks in advance

derek

Derek,

You have it backwards a bit. The print on the PVA sheet is placed PVA side down in hot water. The hot water dissolves the PVA leaving the ink layer behind. The hydrophobic ink floats on the hot water and the part is pushed through the thin film. The water pressure adheres the ink layer onto the irregular surface of the part. In the old days, this ink layer was thermally bonded to the part in a subsequent step but the newest version of the process uses an "activator" to soften the ink layer, allowing it to bond to the part. The "activator" is acutally a plasticizer dissolved in a volatile solvent that is sprayed onto the ink layer while it floats on the surface of the hot water. Hot water speeds up the solvent evaporation (xylene, MEK, butoxyethanol for example) and also speeds up the plasticizer's softening of the ink layer. The plasticizer also softens the primer which has been applied to the part and helps to create a strong bond.

In latex type paints, these plasticizers are referred to as coalescing agents and could probably be used in your process. Search for coalescing agents (Texanol for example) that have limited water solubility and you are likely on the right track. I've seen dimethyl- and diethyl phthalate used in water transfer printing as an "activator" but I think something like Texanol is a bit safer.

Hope it's helpful.

 

[japcarmaniac]

dimethyl- and diethyl phthalate are extremely hard to find here in the uk. if a plasticiser needed the arent those other formulas I've been looking at useless? here is one

xylene 50%
isobutanol 9%
mek 12%
ethylacetate 29%

 

[chemisttree]

I don't know enough about the polymers used in the dye to tell you. You've listed some solvents with varying volatility. The boiling points are:

xylene 140C
isobutanol 108C
mek 80C
ethylacetate 77C

The boiling points of the plasticizers I mentioned are:

Dimethylphthalate 284C
Diethylphthalate 298C
Texanol 254C

Notice anything different about them? The water transfer is performed a elevated temperature, not high enough to boil away these solvents but I'm sure they evaporate pretty quickly. The plasticizers stick around for a lot longer and are likely much more effecient at softening or tackifying the dye layer.

If you can't get the phalates, perhaps you should try Texanol. You CAN get that in the UK.

 

[japcarmaniac]

hi, first off thanks for the help i really appreciate it. I've found a company who can supply the texanol here in the uk.

am i right in assuming that if the solvent has a higher boiling point then it will hang around longer than one with a shorter boiling point and with texanol added that should give a longer window of time for dipping and also more 'pliability'.

all i need to do now is experiment with mixtures and i don't think ill need as my chemicals as i first thought although i did here that the reason all those solvents are used is to make it more universal to different grades of pva film.

here is another formula i have

65% ethyl acetate
15% butoxyethanol
20% BBzP. <-- possibly replace with texanol? i can get bbzp but its £150 a litre:(

 

[chemisttree]

am i right in assuming that if the solvent has a higher boiling point then it will hang around longer than one with a shorter boiling point and with texanol added that should give a longer window of time for dipping and also more 'pliability'.

I think the solvent is around so that you can evenly apply small amounts of the plasticizer using simple equipment like an aerosol can. The solvent dilutes it and allows it to be sprayed evenly. Use too much and the ink will be soft for a long time and might need extended heat treatment for it to firm up on the part. The Texanol or plasticizer or coalescing agent helps to soften the polymer matrix of the ink and to bond it to the primer on the part. My point about the boiling point was to show you that the solvents are made to go away and leave the plasticizer behind. The plasticizer has a much lower volatility so it sticks around to do it's thing.

all i need to do now is experiment with mixtures and i don't think ill need as my chemicals as i first thought although i did here that the reason all those solvents are used is to make it more universal to different grades of pva film.

Very likely. Since I only have what you write here to judge your understanding of the process I'll make the following observation. It might be common practice to refer to the design on a PVA film as a "PVA film" but I doubt the ink layer is itself composed of PVA. The PVA layer is there to provide support for the otherwise gossamer ink layer and allow it's manipulation without damaging it. Once it is placed, PVA side down, on the surface of the water the PVA dissolves away into the water. I suppose they could have about as easily used rice paper rather than PVA. The activator spray acts on the ink layer only, not the PVA layer. It would be more correct to say that those different solvent recipes are used to make it more universal to different ink layer compositions. It may sound like I'm nitpicking but I'm only doing it to ensure that you have the right info and don't go off trying to test solvents with different samples of polyvinylalcohol rather than different brands of ink designs.

here is another formula i have

65% ethyl acetate
15% butoxyethanol
20% BBzP. <-- possibly replace with texanol? i can get bbzp but its £150 a litre:(

That formula looks good to me. I wonder if BBzP is butylbenzylphthalate? That would be a reasonable choice, IMO.

Here is a http://www.specialchem4coatings.com/product-directory/film-forming-coalescing-agents_0_12425/index.aspx?did=0 that helps you choose a coalescing agent (which I believe is the same thing as an 'activator' in the water transfer process). You can see on this website that not only do you need to choose a range of solvents but perhaps also the appropriate 'activator' as well. Also note that in some cases the solvent can be a coalescing agent.

 

[japcarmaniac]

thanks again for your help. ill let you know how i get on and what was successful and what was not.

 

[trdaytona]

Hi, just a not that might help you with the activator, I have been printing for some now and like you had trouble obtaining the activator, the formula i have is as follows

Xylene = Dimethybenzene 42%

Iso-butanol = isobutyl alcohol = methyl propanol 5%

Butyl = butyl acetate = butyl ethanoate 17%

B-butanone = methyl isobutyl ketone = MEK 8%

Methyl =methyl acetate = acetic acid methyl ester =

methyl ethanoate 28%

As you can see some of the chemicals all have different names ( trade names from manufactures) all the same chemical though.

The formula that i have been using is as follows,

Xylene 60%

n-Butyl acetate 25%

n-Butanol 10%

Cyclohexanone 5%

The problem you will have is obtaining these chemicals in small quainties and the cost plus storage they are quite danderous to have sitting around as you can see some you need very little of but you have to buy large amounts.

My background is spray painting and panel repaires so i was quite suprised when using the activator the smell was quite familair eg: thinners to be precise 2pak thinners not acrylic thinners so i tried it and the result is ammazing exactly the same have been useing it for some time now easy to obtain cheap to buy in quaintities from 500 mil to 25 litres from any automotive paint suppies store.

Buy a small amount =500 mil and try it, rememmber ( 2 pac thinners only) hope this is of some help to you as people try to keep this prosses a secet.
Cheers, Don.

 

[japcarmaniac]

Hi don, that's great advice thank you. Do you have a preferred brand as there's lots on the market and some are universal? Thanks again.

 

[trdaytona]

Hi, I just use any universal 2pak thinners' when you go to purchase it you should ask if they have the MSDS ( Material Data Safety sheet ) for the one that you purchase , it will list all the chemical formula and ratio's. When I tried to get the activator made here the first thing that alerted me to this was they asked me why I wanted to mix my own thinners as this was a basic formula for thinners.

I did a test using first the activator on some front computer panels and the the same using the thinners, the results where pretty much the same, the trick is your water temp, the spread you allow the film to have afer activation and the pressure at which you apply the activator.

If you need any info on abtaining the film and not paying though the nose I can give you all the info that I use to deal direct with the manufacturers as it saves you a small fortune.

You can contact me at visualtransformers@hotmail.com if you wish for mor info.

Cheers, Don.