Figure 3.12
 
64
Bacterial Cellulose
(a)
(d)
(b)
(e)
(c)
(f )
Figure 3.12
ning.of.BNC.generation,.b).completed.BNC.fleece,.c).start.of.continuous.harvesting.and.generation.of.new.BNC.at.the.vacant.surface.of.cultivation.medium,.d).growing.of.the.BNC.fleece.
during.continuous.transportation,.e).harvesting.via.belt.conveyor,.f).continuous.cleaning.
The.BNC.generation.process.within.this.pilot.plant.can.be.subdivided.into.
the.following.stages.(see.Figure 3.12).(Kralisch.et.al..2011).
. 1..After. inoculation. of. the. culture. medium,. the. BNC. generation.
becomes.visible.in.the.form.of.a.mechanically.unstable.prepolymer.
with.a.wide.meshed.fiber.network.
. 2..A. plane. BNC. material. with. a. uniform. surface. is. generated. with. a.
growth.thickness.of.the.material.of.0.5–1.5.mm/day.after.the.surface.
of.the.prepolymer.is.completely.closed..Depleted.culture.medium.is.
led.out..The.initial.fed-batch.cultivation.is.switched.to.a.slow-moving.cultivation.and.continuous.harvesting.between.day.7.and.10.
. 3.. At.the.vacant.surface.of.the.cultivation.medium,.new.BNC.is.generated.
. 4..During. its. growth,. the. BNC. fleece. is. continuously. transported.
through. the.bioreactor..The.sizes. of.the.fleeces. can.be. adjusted. by.
the.speed.of.transportation.
. 5..The.material.is.harvested.via.several.belt.conveyors.
. 6.. The.material.is.then.treated.in.cleaning.baths,.integrated.in.the.process.