Following are Cited from http://www.traegergrills.com
"Only the finest hardwood raw materials are sourced from all over the country. The pure, raw material (sawdust) is then pulverized with hammer mills and dried. The dried material is then processed under heat and pressure. Lignin, which is the natural glue which holds plant fiber together, softens above 100 degrees Celsius, permitting the material to change shape. The hot lignin then acts like a glue to bond the pellet together. Pelleting employs a hard steel die which rotates against rollers forcing the material through the die with pressures of over 10,000 PSI. As the pellet is forced through the die it is sheared off at the specified length, cooled, screened, and bagged.
General specifications for wood barbecue pellets are:
100% hardwood "
My burner BURNS wood pellet.
A normal wood pellet is made from "100% hardwood"
a "100% hardwood " will burnt to ASH, not any clanker,
If a pellet becomes "very resinous and sticky" and "gummed up ", it must not be 100% Wood pellet. Usually it must have much more additive.