In agriculture, a pulper
is a machine designed to remove pulp i.e. the soft flesh from agricultural
produce. For example, in coffee
growing the ripe, red cherries
are picked from the coffee bushes and prior to fermentation
and later drying the soft pulp needs to be removed (otherwise a potentially uncontrollable fermentation/rot will occur). In the case of coffee the pulping is normally done in a pulper that is either hand-cranked or engine-driven; the beans are emptied into an elevated hopper
and then dropped through a narrow slot within which they come into contact with a rotating spiked drum that removes the pulp or flesh. Again in the case of coffee, the sticky beans that result from this process then have to be washed, fermented, washed again and dried prior to further processing (milling to remove the parchment
) and then roasting.
In the wood-processing industry connected to paper-making, a pulper is a machine that mechanically and chemically processes the fibers of wood chips, or artificial non-woven fibers, to reduce them to pulp.
Post-consumer waste is re-pulped, in one of the processes involved in recycling it.