The same inspection procedure must be carried out as
for bagged coffee (see topic 05.02.04): a container is either suitable or it is
not.
The liner
itself
This is best described as an oblong sack or envelope
whose size is equivalent to the inner space of a 20 foot container (TEU). It is
attached to hooks in the upper corners after which loose coffee is blown in,
gradually filling the entire container with coffee. Container liners are used in
the containerized bulk shipment of dry free-flowing cargo such as coffee. They
are quick and simple to install and enable bulk cargo to be shipped door to door
with a minimum of handling, thereby minimizing cargo spillage and waste.
Liners are usually made from virgin polyethylene
(film or woven polyolefins), allowing coffee to be transported safely in an
enclosed chamber, thus avoiding contamination from pollutants and salt sea air.
The liner therefore protects the coffee from external influences such as
moisture and, in case of condensation occurring on the container's inside walls,
it ensures that this does not affect the coffee.
Once full the liner is sealed and not opened again
until discharge at destination, either into the reception system of a roasting
plant, or into a silo storage system, for example in a port. Bulk shipping means
no export bags are required anymore whereas more coffee fits into the container
(variable but generally about three tonnes more), thus saving on transport
costs. Bulk coffee is discharged mechanically at the receiving end, thus
avoiding the use of expensive manual labour. In Western Europe the disposal of
empty coffee bags costs money as well. Because the United States mostly works on
the ex dock sale system it seems relatively little coffee goes there in bulk.
But today's large European roasters receive as much as 90% in bulk. Being able
to supply coffee in bulk is a definite advantage therefore, with cost savings
for both shipper and receiver.
Fixing the
liner
The inner polypropylene liner must fit snugly
against the walls, roof and floor when full - improper placing of the inlet
could cause tearing - and the load must be as evenly leveled as possible. The
liner's roof must not sag but must be tight so at no time will the inlet or roof
rest on the coffee after loading. Ideally, built-in reinforced straps in the
liner's front panel (bulkhead) will prevent bulging when the container is full,
thus allowing for easy closing of the doors. (Strapping ropes can also be used.)
There should not be any pressure on the doors when closed after loading. The
liner must be properly fastened to the container's interior, also at the far
end: at the point of discharge the container is tilted to enable the coffee to
slide out of the liner, rather than the filled liner sliding out of the
container.
Filling the
container
Containers can be filled in two ways. One method is
to take the coffee from the silo with the aid of a blower, or to empty
individual bags into the blower's reception hopper. Blowing air into the liner
makes it align itself with the walls, roof and floor of the container. Once the
liner fits correctly inside the container, the blower then spews the coffee into
the now fully lined container. During this process the displaced air must be
able to escape.
Do not blow a heap into the centre, leaving space at
the rear and the doors, but fill the liner evenly. To ensure the coffee stays
away from the hot container roof, avoid as much as possible contact between the
stow and the liner's roof panel, preferably by a margin of about 70 cm. Some
receivers stipulate that there must be
space between the liner's roof panel and the top of the coffee load.
Another way is to fill the container using a
telescopic conveyor belt that extends into the lined box. This eliminates the
need for air pressure and therefore the risk of damage to the beans.
See topic 05.02.09 to view
a lined bulk container.