Download Plastics Technology: Migration, Coextrusion, Blow Molding, and Foams and more Quizzes Production and Operations Management in PDF only on Docsity!
migration
transfer of migrants (monomers, solvent residual catalyst additives) from the packaging material into the packaging product TERM 2
global migration
DEFINITION 2 the quantity of migration TERM 3
specific migration
DEFINITION 3 transfer of certain substances that have transferred. TERM 4
shelf life is affected with migration
DEFINITION 4 sensory quality adhesive, ink, pigments, printing solvents examples - milk cream printing solventsdesired migration substances such as antioxidants like vitamin E TERM 5
migration depends on
DEFINITION 5 initial amount of the migrantequilibrium partition coefficient b/t the plastic and the fund
other parameter used to express barrier
properties
permeance (R) gas transmission rate (GTR) water vapor transmission rate TERM 7
gas transmission
rate
DEFINITION 7 quantity of permeant flowing per unit area per unit timefor water = water vapor transmission rate (WVTR) TERM 8
factors affecting permeability
DEFINITION 8 chemical structure of there polymerchemical structure of the permeant moleculehumiditytemperaturephysical properties of the polymerpermeant concentration TERM 9
mass transfer coecfficients P=D*S
DEFINITION 9 D = diffusion coefficient - measure of how fast a penetrant will have within a polymerS = solubility coefficient - gives the amount of penetrant sorbed by the polymer from the contracting phaseP = permeability coefficient - shows the barrier characteristics of a polymer TERM 10
P=DS=(ql)/(Atchangep)
DEFINITION 10 p = permeability coefficient (low p=good barrier)D = diffusion coefficient - measure of how fast a penetrant will have within a polymerS = solubility coefficient - gives the amount of penetrant sorbed by the polymer from the contracting phaseq = amount of permeant transferred through the plastic filmA = area of the plastic filml = thickness of the filmt = timechange p = pressure difference
diameter of the parison
usually nearly the same as the diameter of the container finishcontainer with offset neck/handle require a wider parisonrecommended 4 to 1 container diameter to praise die TERM 17
steps
DEFINITION 17 extrusion of a hollow plastic tube or parison in downward directionclosing the 2 halves of the mold around the tubeinsert blow pinblow airexpansioncool down of mold with waterejecttrim flashmelt strength * dimesnions/ratio TERM 18
new technology
DEFINITION 18 thermoforming bottles made of sheet - multilayers not worried about melt strength TERM 19
blow molding
DEFINITION 19 process in which air pressure is used to shape the inside of the object while the mold shapes outside TERM 20
blow molding for bottles jars and drums
DEFINITION 20 cannot be produced by injection blow molding
types of blow
molding
injection blow moldingextrusion blow molding TERM 22
extrusion blow
molding
DEFINITION 22 process by which combines the extrusion of a parison with blow molding of the finished container TERM 23
characteristics of extrusion blow
molding
DEFINITION 23 more expensive than injectionmost economical process for making plastic bottles except really small bottles (<200 ml)accurate control of of container wall thickness as not as good as it is for IBM
- starting point the same (preform)capable if producing a very wide variety of shapes - offset necks and handlesconsiderable scrap production - usually reacheduse resin with sufficient melt strengthdon't use PETE TERM 24
stretch blow molding
DEFINITION 24 production of preform by injection molding or extrusion blow moldingpreform conditioned just above the Tg of the material bottle Finnish maintained coolpreform placed in the moldblow moldingbiaxial strength of the materialTb/Tg and Tm TERM 25
hot fill bottles
DEFINITION 25 minimize4 bacterial loadfilling T = 82-95 deg cel
final product will depend on beads
desired final shapeblock of materialthere final product depends on the slit and diean annular die TERM 32
extruded polystyrene foam
DEFINITION 32 foam produced by extrusionPS resin plus blowing agent + nucleator blended in an extruderblowing agent which produces bubbles and afterwards it vaporizes it forming cellsquantity determines density of the foam
