Some mills survive by shipping their waste water to a large wood pulp mill nearby, others have to close down. There is a clear shift in capacity towards countries that do not as yet take environmental problems very seriously. One reason for the high price of hemp pulp is the inefficient pulping processes used. Most mills predominantly process the long hemp bast fibres, which arrive as bales of cleaned ribbon from preprocessing plants located near the cultivation areas. The bales are opened and fed into a spherical tank, called a digester.
Most mills use sodium hydroxide and sulphur cocktails.
After cooking, the cooking chemicals and the extracted binding components are separated from the fibres by washing with excess water. This is where most of the polluting waste emerges from the process. Often wastes are discharged as such into the local surface water. The remaining clean fibres are then fed into a Hollander beater, which is best compared to an industrial size bathtub, with a large wheel revolving around a horizontal axis at one point in the tub. The wheel pumps the pulp round and round, and meanwhile cuts the fibres to the right length, and also gives the fibres the required surface roughness for better bonding capacity.