A method of preparing a hot melt adhesive composition, comprising (A) feeding a polymer blend into an extruder; wherein the polymer blend comprises (a) a first propylene-based polymer, wherein the first propylene-based polymer is a homopolymer of propylene or a copolymer of propylene and ethylene or a C.sub.4-C.sub.10 alpha-olefin; and (b) a second propylene-based polymer, wherein the second propylene-based polymer is a homopolymer of propylene or a copolymer of propylene and ethylene or a C.sub.4-C.sub.10 alpha-olefin; wherein the second propylene-based polymer is different than the first propylene-based polymer and wherein the polymer blend has a melt viscosity of 1,000 cP to 20,000 cP at 190 C.; (B) feeding one or more adhesive components, selected from at least one of a tackifier, wax, antioxidant, functionalized polyolefin, oil, and combinations thereof, into the extruder; and (C) recovering an extrudate from the extruder, wherein the extrudate is a hot melt adhesive composition.

A twin-screw extruder comprises: a barrel having a space formed therein; a left screw and a right screw received in the space; and a drive mechanism for rotating the left screw and right screw, wherein the left screw comprises a left fiberization screw, the right screw comprises a right fiberization screw, wherein a compression space is formed between the left fiberization screw and the right fiberization screw in which the powder is compressed, wherein each of the left fiberization screw and the right fiberization screw includes: a hollow portion connected to a shaft; and a screw portion formed on an outer circumference of the hollow portion, and wherein the screw portion has a flight groove recessed therein through which the powder passes axially.