Blow Molding

Question 1

plastic bottles are generally made using a process called

Answer 1

blow molding

Question 2

2 types of blow molding

Answer 2

extrusion blow molding
injection blow molding

Question 3

in ________, the die bends downward in preparation for the blow molding

Answer 3

extrusion blow molding

Question 4

a hollow tube acting as a preform of the bottle before it is blown into its final shape

Answer 4

parison

Question 5

a cavity or form (usually made of metal) used for shaping a fluid or plastic substance

Answer 5

mold

Question 6

excess plastic and is cut off or trimmed from the bottles

Answer 6

regrind

Question 7

most plastics undergo _____ providing they can have enough strength in the melt form or they have a low melt flow rate

Answer 7

extrusion blow molding

Question 8

common examples of plastic that can undergo extrusion blow molding

Answer 8

PE, PP, & PVC

Question 9

most extrusion blow molding mols are made of

Answer 9

aluminum or beryllium copper

Question 10

is the most common machine configuration wherein two sets of blow molds are used

Answer 10

“shuttle” blow molder

Question 11

clear or translucent stripe that allows consumers to see the content level

Answer 11

viewing stripe

Question 12

the main difference between extrusion blow molding and injection blow molding

Answer 12

an additional step - injection molding

Question 13

in this process, a rod is used to mechanically stretch the parison before air is blown to form the bottle

Answer 13

injection stretch blow molding

Question 14

why is injection blow molding favored in making PET bottles for carbonated beverages

Answer 14

the mechanical stretching orients the polymer molecules, thus increasing stiffness and barrier

Question 15

one drawback of conventional injection stretch blow molding bottles is…

Answer 15

their tendency to shrink when hot filled

Question 16

EBM vs IBM in molds

Answer 16

EBM requires single mold while IBM requires two molds

Question 17

EBM vs IBM in handleware

Answer 17

EBM is readily produced; IBM is difficult

Question 18

EBM vs IBM in multilayers

Answer 18

EBM coextruded & multilayer bottles readily produced; IBM multilayers difficult

Question 19

EBM vs IBM in regrind

Answer 19

EBM produces trim regrind; IBM no regrind or other secondary operations

Question 20

EBM vs IBM in container size

Answer 20

EBM large containers possible; IBM limited size containers

Question 21

EBM vs IBM in precision

Answer 21

EBM not so precise or accurate; IBM high-precision dimensions

Question 22

EBM vs IBM in no. of cavities

Answer 22

EBM limited no. of cavities; IBM more cavities possible

Question 23

EBM vs IBM in wide mouth jars

Answer 23

EBM wide mouth jars awkward; IBM wide mouth jars easy to make

Question 24

EBM vs IBM in material distribution

Answer 24

EBM material distribution needs adjustments to be consistent; IBM better material distribution

Question 25

how to identify EBM products?

Answer 25

there is a mold pinch-off in EBM products; parting line across the bottom where the mold halves come together

Question 26

how to identify IBM products?

Answer 26

IBM products have a circular bull's eye pattern on the container bottom

Question 27

EBM processes are based on a common underlying sequence

Answer 27

1. parison ready 2. mold closes over parison 3. mold moves to one side. parison inflated to fill mold. extruder forming new parison. 4. mold opens, bottle removed and trimmed

Question 28

injection blow molding combines

Answer 28

injection molding and blow molding

Question 29

two molds for injection blow molding

Answer 29

1. the injection mold(s) to produce the preform 2. the companion blow mold(s) to blow the container

Question 30

a variation of IBM uses a rod to stretch the preform during blowing

Answer 30

injection-stretch blow molding

Question 31

a major application for injection-stretch blow molding is the manufacture of

Answer 31

PET carbonated beverage bottles

Question 32

is the main difference between EBM and IBM

Answer 32

injection molding step

Question 33

T or F. the die in IBM bends upward.

Answer 33

False. Melt is injected directly into the mold

Question 34

The parison in IBM is shaped similar to that of a ____

Answer 34

Plastic tube

Question 35

T or F. in IBM the parison is transferred to the blow molding machine and heated first before being blow molded like that of EBM

Answer 35

True

Question 36

____ refers to a process that uses a rod to mechanically stretch the parison before air is blown to form the bottle

Answer 36

Injection stretching blow molding

Question 37

T or F. the mechanical stretching orients the polymer molecules, thus decreasing stiffness and barrier.

Answer 37

False, increases

Question 38

T or F. Injection blow molding is a process favored in making PET bottles for carbonated beverages

Answer 38

True

Question 39

One draw back of conventional ISBM bottles is their tendency to ____

Answer 39

Shrink when filled with hot substance

Question 40

T or F. mold pinch offs appear in EBM products

Answer 40

True

Question 41

T or F. Bulls eye patters appear on IBM

Answer 41

True