First of all, are you using a 510 or 306 style atty? It does make a difference since the 306 style puts the drip tube a lot closer to the heat source, and these will melt with heavy
vaping because they are mostly made of acrylic which really sucks in environments that are exposed to heat and chemicals.
Delrin is a very good plastic when it comes to heat and chemical resistance. Delrin is a thermoplastic with a melting point of around 350 degrees. In simple terms, that means that the plastic could melt, but should solidify when it cools. There is another term that polymer engineers (I used to be one in a previous life) use called heat deflection point which is around 250, if my memory serves me right, but that is important in applications where is plastic is mechanically stressed as in a gear. Your tip is not in a situation where it is under a lot of stress.
I doubt that your atty tube gets that hot in a 510, but it is possible but not probable that it gets that hot with a 306, or hot enough to melt acrylic.
If it stays sticky after it cools down, there is some sort of chemical reaction going on.
My first conclusion is that the material is not Delrin, but acrylic. It would not surprise me to see manufacturers trying to save a few cents by substituting a cheaper plastic. Under most circumstances, the consumer would never know the difference. Although not foolproof by any means, one easy way to see if the material is not Delrin is if the drip tip allows light to pass. Delrin is neither translucent nor transparent. Again, I will repeat the caveat since they could throw enough filler in there to prevent the passage of light.
Don't mean to scare you, but stop using the drip tip immediately and order some new ones from a reputable supplier like Super T, or go to a stainless or glass drip tip.
