packaging Flashcards
main purpose of packaging
protection
the passive role of packaging
protecting and marketing the product
active role of packaging
[processing, preservation, retaining safety and quality
primary function of packaging
minimise the transfer of heat and light
prevent gas transfer
prevent the physical damage
secondary function of packaging
facilitate distribution
other functions of packaging
communication
dispersing and dispensing
unitisation
packaging design considerations
functionality
energy/production efficiency
image
display
environment
cost
what is bulk density
amount of powder by weight that is present in a defined volume
filling, sealing and coding considerations
fillling
orientation
state
fragility
temperature
sealing
lid or seal
tamper-proofing, coding and labelling
secondary and tertiary packaging considerations
units/pack
diensions
loading effciency
closure
cost
strength
distribution methods
storage
environmental impact
type 1 plastic
PET
type II plastic
HDPE
type 3 plastic
PVC
type 4 plastic
LDPE
type 5 palstic
PP
polypropylene
type 6 plastic
PS
polystyrene
or
EPS
expanded polystyrene
type 7 plastic
other
what plastics can be recycled in NZ
1, 2, 5
what does packaging limit or control
light and heat
movement of substances
what is the barrier property measured by
permeability co-efficient- Pb
-measure of the packaging materials resistance to a permeant
degree of protection depends on…
chemical and physical properties of the packaging material
5 steps of mass transport
collision
adsorption
dissolves into polymer
diffusion
desorption
describe the 5 steps of mass transport
collision: contact of permeant with packaging
adsorption: attachment of product to packaging
dissolving: moves into the packaging
diffuse: moves out of the packaging
desorption: unattachment
factors affecting permeation
polarity
concentration or partial pressure
the thickness of the packaging material barrier
molecular packing
the surface area of the barrier
temperature and humidity
how does polarity affect permeability
the greater the difference in polarity the slower the rate of disolving will be
how does molecular packing affect permeability
orientation and amount of crystallinity can make it easier/harder for permeant to get through
the permeability of a polymer is influenced by
chemical composition
chemical structure
characteristics of HDPE
linear, crystalline structure
characteristics of LDPE
branched, less crystalline structure
characteristics of LLDPE
linear with many very short side chains
semi-crystalline
least permeable of LDPE, HDPE, LLDPE
LDPE
units of measurements for gas and water transmission rates
g m-2 d-1
what are gas/water transmissions rates used for
to calculate how many days before a product becomes unacceptable