Mechanical pulping
Mechanical pulping means a pulping process that only uses mechanical and thermo-mechanical processes to reduce wood to a fibrous mass. The mechanical pulping processes include, but are not limited to, stone groundwood, pressurized groundwood, refiner mechanical, thermal refiner mechanical, thermo-mechanical, and tandem thermo-mechanical.
Source
40 CFR § 63.441
Scoping language
All terms used in this subpart shall have the meaning given them in the CAA, in subpart A of this part, and in this section as follows: