extruding room-temperature glue from a toy printer I'm designing

I'm designing a toy printer that has normal XYZ axes but a motor-driven syringe for the extruder. It needs to extrude room-temperature glue or glue-like stuff. I'm having trouble finding a glue that dries fast and hard but would not clog up the syringe. Everything needs to be room temperature for kid's safety. Does anyone have any idea what I could use?

BTW, it can also dispense stuff like icing for cookies but my main goal is to build a benchy, albeit a rather crappy benchy. It is a toy after all.

... look into dispensers and paste-extruders -- there were several developments ... and another 3D-printer, started at the same time as RepRap was the "fab@home"-printer with motorized syringes instead of FDM-extruders ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

I just did a quick wikipedia look at fab@home. Fascinating. It was interesting that it mentioned printing play-doh. Hasboro has a hand-held dispenser for kids to draw 3D objects. It doesn't use the same play-doh, but a more liquid version. It is called dohvinci.

I wonder if I could use dohvinci play-doh. I don't see how kids buying that product and putting it in the 3D syringe would be any kind of copyright or other trade issue.

Paste also looks interesting. I would have to find somewhat thin paste, or maybe not.

I've considered model cement but I don't think it has any solids in it. Just chemicals.

Thanks for the suggestions.

UV curing glue seems to be the hot item these days. Obviously the syringe needs to be made UV proof. Then have UV light directed at the print. Print on to tape though as your print will get stuck to the bed.

... this UV-glues are pretty toxic, before cured!! - so not good for toys or children ...

I'm using UV-cured pastes and glues with high-power 405nm-LED's to cure ... but again - neither the glues/pastes, nor the 405nm LED's schould be left alone to children!

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Yeah, unfortunately UV light is bad for you. That would be a great idea for an adult product. I wonder if there is anything else that could be cured right after printing.

... I have some samples from dyed "air-drying" sanitaire silicone -- if you insert a pause to let the actual slice dry, this would be the easiest way ... but it's something "smelly"

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Thanks again. I will try the sanitaire silicone. I was expecting to pause between layers no matter what material I use. They would have to dry. Smelly is no problem, as long as it isn't toxic.

I googled "fast drying glue" and found fast-drying tacky glue. I'm hoping tacky glue will allow stacking without too my drying, since it is tacky. It may be hard to dispense.

So far I am going to try fast-drying tacky glue, dohvinci play-doh, and this sanitaire silicone.

... maybe "Elmers glue" with some dust infill could be a DIY solution?

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

I've done research on the UV solution. There is glue that is non-smelly according to the product feature list and reviews. Also I've found that UV lights are safe. They are used for psychadelic lighting, nail polish drying, and curing resin of course.

The UV that is dangerous if the far-UV that is used to disinfect a room. They are being used for covid. You must leave the room after tuning on and not doing so will cook your eyeballs, A fashion show once used them for their cool color and everyone who attended went to the ER.

So I'm adding UV to my list to try. It is getting to be a long list, which is good, but a lot of work:-(

Dust (or other filler) is a good thing to try for all of the glues I'm trying. Thanks for the idea.

... 405nm UV may be harmless for skin an nails, but it's wrecking the retina!! -- and "not smelly" is one thing ... but, all the resins are toxic, carcinogenic and mutagenic, until complete cured!! ... otherwise they won't start the polymerisation at UV exposure ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

I guess you might be right. I saw shields for the fumes, and glasses for the UV, for sale. :-)

Damn. I was looking at specs for silicone glue and it said "keep away from children". So now my list is down to just tacky glue, whatever that is, and dohvinci play-doh.

... you can search for some English infos to "plaast polymorph" - [www.bengs-modellbau.de]

Maybe an interesting material too ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Thanks. Unfortunately plaast polymorph requires heating, which would add too much expense.