mdf cutting

hey guys, i am cutting .74" mdf at the following parameters, cut depth .3", feed rate 4"ips, 14000rpm...and i am noticing that there is a brownish gum stuck to my .25" down spiral bit. any ideas on what this may be and why it is happening?

I think the 14k is a bit too fast. I have had success at 11 to 12 k as it keeps the bit cooler. The other necessity is to start with a sharp and clean bit so there is again less heat and nowhere for the gunk to easily stick. If its the cheap quality mdf it's hard to know, the door quality stuff cuts better for me. FYI wear a mask even if you think your dust pickup is working, it's nasty stuff to breath

8k is plenty and unless you have a small machine full depth pass is fine. I use two a climb cut then then a cleanup pass full depth.

I cut it at 5ips 12500 rpm full depth

thanks guys, clearly i my rpm is to fast...