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Raw
material storage: More than clean environs
Proper
storage of raw material is no longer confined to good and clean
environment. It includes various related aspects like transportation
and handling of materials, building structures, lighting, atmosphere
amongst others, says R Kedareshwar
THE
process of manufacturing starts from inwarding of raw material from
approved vendors either from within the country or from outside
the country. Bulk raw materials like paracetamol, ibu, sulpha TMP
sugar etc. come in trucks in case of local sources and in containers
if they are imported. Local materials coming in the trucks are received
in the receiving bay consisting of covered area under which truck
is parked and the material is moved out either manually or with
a unloading conveyor of cantilever type with adjustable height,
from there it moves down to receiving bay.
In
the receiving bay either the containers are manually cleaned with
a vacuum cleaner or passed through the cleaning station with air
shower or connected a central vacuum cleaning system to remove the
external dust on the carton or pack.
Transportation
of materials
In
case of palletised material, it is picked by hydraulic pallet truck
or with forklift and lowered and moved to the receiving bay. Here
worth noting is Lilly’s driver-less train for transporting
material from receiving dock to staging bay. Further AGVs (automated
guided vehicles) are adopted to move the material from staging bay
to the designated shelf in the rack by programming in the computer.
These units operate without any driver, to avoid mistakes during
inwarding barcode or matrix code is adopted extensively to check
each container at entry and feed into computer.
As
the material is moved from the unloading point to receiving bay
to quarantine area, controlled environment starts thus necessitating
protections like rodent traps, air curtains and pesto-o-flash units
that are installed, monitored and maintained in this area. Entry
doors in these areas are either normal rolling shutters which are
opened and closed manually operating the with worm drive mechanism
or recent version of rolling shutters with minimum number of joints
and made out of pre-coated and pre-painted sheets. These new types
of shutters have facility for cordless remote control for opening
or closing down. A tubular rubber gasket at the bottom ensures gap-free
closure, thus restricting entry of rodents and crawling insects
especially during night times in the monsoon (when air curtains
are off).
Next
choice, now available is flexible PVC rapid auto roll doors with
full width clear vision panel available with various choices of
activation like push buttons, induction floor loops, radar motion
detectors, PE sensor, pull-cords and remote control. These modern
shutters does not need any lubrication in the guides unlike in conventional
ones (grease applied in the guides attracts lot dust and becomes
an eyesore at the point of material entry).
Clean
environment
Pesto-o-flash
units need to be located properly to attract and kill the flying
insects entering into the controlled area. These units need to be
regularly monitored for extent of insects being killed and for lamp
life as the life of the lamp is limited to six to eight thousand
hours of effective operation.
During
unloading rolling shutters are kept open, so it is preferable to
have flexible ribbed PVC curtains with proper overlap after rolling
shutters. It is always advisable to connect the receiving bay with
a telephone to main stores to avoid outside personnel like truck
driver’s entry into the controlled area. Installation of access
controls at all entries to store restricts the entry of unauthorised
personnel.
Its
very essential to have a bitumen road or cement concrete floor on
the land adjoining the unloading bay to control the dust level inside
the receiving bay. Inside the stores floor, area needs to be hard
faced either with ironite concrete or vacuum dewatered concrete
floor or concrete with floor hardeners to be employed to withstand
movement of forklifts with heavy loads. This avoids chipping of
floor otherwise, resulting in pits on constant usage further becoming
a source of dust.
Prefabricated
structures
Moving
on to walls and ceiling, usually the brick masonry walls with plastering
and painting to a smooth finish or prefabricated and pre-coated
steel sheets are available for walls and roof. This type of prefabricated
sheets and structures are very light thus facilitating very long
spans without any intermittent supports enabling effective usage
of available space.
One
should remember that this type of prefabricated material is light
so this cannot be employed if material is stacked against walls
further one needs to be cautious while selecting the roof with trusses
and purlins, as the space between these members and the roof sheet
is major concern, these spaces are difficult to access for cleaning
due to their location at high ceiling level and are vulnerable for
collection of cobwebs.
So
appropriate covers are to be provided for trusses and purlins which
should be easily cleanable. In spite of higher cost, for the shear
reason of difficulty in maintaining (where actives are stored),
a simple RCC roof with roof-to-wall coved joints should still be
a good consideration in our country. This also facilitates for construction
of first and higher floors in future.
Adequate
lighting
Lighting
in the storage areas should facilitate the operating staff to read
the labels on the container before moving for dispensing. Fluorescent
lamps (tube lights), MV lamps, metal halide luminaries can be considered.
Fluorescent lamps light reach is generally upto 12 ft. So, to fix
the fluorescent lamps at these levels, one needs to suspend the
laminar from the ceiling, which is the major concern for collection
of dust and accumulation of cobwebs.
Second
option of M V lamps, reach is high and can be fixed to ceiling without
suspending but during every power interruption, to switch back and
glow to normal level it takes minimum ten minutes. Next option is
low bay metal halide luminaries of indoor variety can be fixed to
ceiling. It has good reach up to 15 to 17 ft. and highly energy
efficient compared to M.V. lamp, but these fixtures also do not
switch on instantly in case of power interruption. So a combination
of fluorescent lamps and low bay metal halide fixture gives good
option ensuring minimum amount of lighting during power interruption
and very good lighting level.
The
writer R Kedareshwar is with Medreich Sterilab Ltd, Bangalore
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