About FO bonding with wax...

[PhoenixFyre]

I really did try to thoroughly look for the answer to this before asking, so forgive me if the answer is out there and I missed it.

 

If anyone has the time, could someone please explain to me the "scientific" happenings of fragrance oil bonding with wax? I have been trying to Google an answer for this, searched through the different candle groups I belong to, and haven't really been able to find a detailed explanation. The most I can find is that you shouldn't add fragrance oil to wax at too high a temp because it can burn off, but the wax still needs to be hot so it can "bond" or "bind" with the wax.

 

That's the bit I'm interested in...what is the science behind the bonding/binding?

 

I've found many sites that explain how a candle itself works...the wick acting as a capillary, the parts of the flame, the wax vapor, etc. But I'd like to try and wrap my brain around this "bonding" of wax and fragrance oil. Why hotter temperatures? Why does this help the fo and wax bond? Why not a lower temp? How does stirring play a role? (Is the jury still out on that one...whether you need to stir for a full two minutes, less time, or matter of preference?)

 

I hope this makes sense. If there was a post about this on here, then please feel free to just give me the link to save yourself the time of explaining it again. I appreciate your time, everyone!

[Guest OldGlory]

Phoenix, I can't offer an explanation about the 'bonding' or 'binding' of FO to wax, but I would suggest contacting a wax manufacturer. However, someone here might already know the answer and save you the trouble.

I have never stirred my wax/fo combo long, unless I see tiny pools of FO in the bottom of the pouring pitcher. Then, I might even heat the wax up a bit and stir longer. This has happened to me a few times with vanilla.

[Jcandleattic]

In layman's terms, if the wax is too low the FO will not mix (aka bond/bind) to the wax, because they are different substances, Thus they will leave FO sinking to the bottom and possibly become a fire hazard. Heavy fragrances such as vanillas and bakery scents can do this if the wax is not hot enough, or it can also happen if you use more FO than the wax can safely "absorb" (aka bond/bind with). As you are pouring out of your pour pot into your container/mold, you can actually see it at the bottom of the pour pot, so either use less (usually not the problem though), heat the wax a bit more, or stir a bit longer. (I prefer to heat the wax about 5-10 degrees hotter) I only stir until I can't see the FO in there. Never, not even my first time making candles 17+ years ago, did I ever stir for 2 full minutes. Maybe 30 seconds at the longest, maybe. 

 

As far as the wax being too hot and burning off FO - it may burn off a little bit of the FO but it will not effect the outcome in a huge way unless you leave the wax and FO combined at that high temp for very long periods of time (like 20+ minutes at a time) so I wouldn't worry too much about that. 

[kandlekrazy]

I couldn't find the post either but someone scientifically explained it at least once before.  I don't know what wax you use, but I use C3 soy wax and glass pour pots, so I can actually see the fo literally disappear into the wax.

I usually heat to between 170-180 as the mfg recommended.  I also only add the recommended 6%.

Vanillas or heavy I go up between 180-190 because I know they are more difficult to work with.  I like glass even though heavier because I can see what's happening.

[TallTayl]

I'm searching for an article from a wax manufacturer that visually explained it. Basically, wax molecules expand when heated. I think we have all seen how many types of wax shrink as they cool in the containers or molds we use.

Heating wax to the manufacturer's recommended temperature (not necessarily the retailer's/reseller's) expand the wax molecules to encapsulate fragrance molecules of different sizes into a structured matrix as the wax cools. This helps ensure the two substances are well mixed and should prevent the fragrance molecules from falling out of suspension, pooling, forming droplets, etc because the wax is holding the matrix well together.

[TallTayl]

This is not the article i was searching for, but it is pretty good (and oh so long, lol)

http://www.sasolwax.com/sasolwaxmedia/Downloads/Kerzendokumente/Sonstige/Temperature+_+A+Hot+Issue+Print+Version.pdf

[PhoenixFyre]

Awesome, everyone. I appreciate you all taking the time to help and to even find articles for me. This helped me a lot, and I'm going to tackle that article right now, TallTayl, lol. So in a nutshell it sounds like the wax needs to heat up so the molecules can expand and sort of trap the fragrance oil within them to later be released when the wax is again heated by the flame. And thank you for alleviating my fear of burn off. I was always fretful about letting the wax get too hot and the FO burning off (I guess just those jitters of being a beginner).

 

Thank you all so very much!!

[topofmurrayhill]

If anyone has the time, could someone please explain to me the "scientific" happenings of fragrance oil bonding with wax? I have been trying to Google an answer for this, searched through the different candle groups I belong to, and haven't really been able to find a detailed explanation. The most I can find is that you shouldn't add fragrance oil to wax at too high a temp because it can burn off, but the wax still needs to be hot so it can "bond" or "bind" with the wax.

 

That's the bit I'm interested in...what is the science behind the bonding/binding?

 

Scientifically there are two things going on in the candle world regarding FO binding with wax: (1) bullshitte, and (2) the polarity of liquids.

 

The BS part is the idea that something invisible is happening that might relate to fragrance retention or scent throw. Going years back there was talk of this "binding" needing to happen with every fragrance oil, and it was not necessarily something you could see. That part is fiction. If you put FO in the wax, give it a stir, and it disappears and everything is clear, that's as "bound" as it's ever going to get. It's just dissolving one thing in another, and you can see when something is dissolved. Most FOs will do that at more or less any temperature as long as the wax is melted.

 

When it comes to one thing dissolving in another, you mainly have "polar" water-loving stuff and "non-polar" oil-loving stuff. It has to do with how electrical charges are arranged on the molecules. Not something I know a lot about, but the simple part is that polar dissolves in polar, non-polar dissolves in non-polar. FOs presumably are mainly oil-loving or non-polar, so they dissolve in wax, which is also a non-polar liquid.

 

The binding thing could have got started with those vanilla and bakery scents, which seem to have one or more polar components that can be difficult to mix with paraffin. With my favorite vanilla, I heat on a hot plate and plop it in when the wax reaches 190. It's cloudy for a stir or two and then turns clear again. If the wax was too cool or maybe sitting on a cold surface, I'd have watery-looking bubbles of FO on the bottom that would thereafter be VERY stubborn about getting mixed in.

 

However, the issue with vanilla and bakery scents only applies to paraffin. Vegetable oil is a special case of something called "polar oils." It's still oil loving, but its molecular structure better dissolves a wider range of things. Soy wax is vegetable oil, so it will dissolve some substances that might not fully love paraffin, like those vanilla FO components. I'm not sure I've ever seen a fragrance that doesn't mix right into soy wax. It might not throw, but it dissolves a-okay.

 

So for you this should be a non-issue. As long as the wax is melted, you can add FO at any temperature. "Burning off" is another one of those kinda-BS things. It's not that easy to evaporate the FO away to any meaningful extent in candlemaking. Use whatever procedure you prefer and don't worry about it.

[PhoenixFyre]

Thanks, Topofmurrayhill. Your posts always give me more to think about and relax me, too, in a way.

 

I appreciate what both Jcandleattic and you confirmed...that it's not so easy to make the FO disappear to any meaningful degree, so I can delete this from my brain and make room for other things.

 

I had read a post in another group where someone brought up the idea of it not being necessary to add in FO to hot wax but rather to cooler wax. Their theory started going into covalent bonds and science-y talk. Their theory was that the wax is a carrier of the FO and that the FO needs to remain volatile in order to get maximum release from the melt pool, but that if the wax is heated too much it can ruin the volatility and thus make the scent throw weaker and they saw no "evidence" that thermal energy was needed in order to bond the FO to the wax.

 

I don't know if there is merit or not to the idea. I do know the people on this forum have been a wealth of info to me as a novice, so I wanted to see what people here thought before getting too carried away in my own brain. I'll probably test it out for fun to see what happens. I guess I was just more curious if this whole bonding thing was something I could control more.

 

All of you, as always, are terrific and thanks to you all again.