CPE Packaging Materials & Components 2 — Questions and Answers
Question 1: Which property of a packaging material is measured by the Gurley Hill method?
- Tensile strength
- Air permeability (Correct answer)
- Moisture vapor transmission rate
- Burst strength
Correct answer: Air permeability
The Gurley Hill method measures air permeability by timing how long it takes a fixed volume of air to pass through a material sample.
Question 2: What is the primary function of an ethylene vinyl alcohol (EVOH) layer in multilayer flexible packaging?
- Moisture barrier
- Oxygen barrier (Correct answer)
- UV light barrier
- Mechanical strength
Correct answer: Oxygen barrier
EVOH provides excellent oxygen barrier properties in multilayer structures, extending shelf life of oxygen-sensitive products.
Question 3: In corrugated board construction, what does 'C-flute' refer to compared to 'B-flute'?
- C-flute has higher flute count per foot
- C-flute is thicker with lower flute count per foot (Correct answer)
- C-flute has the same thickness but different caliper
- C-flute is used only for inner liners
Correct answer: C-flute is thicker with lower flute count per foot
C-flute is thicker (~4.8mm) and has fewer flutes per foot than B-flute, providing greater stacking strength.
Question 4: Which type of closure is most appropriate for a child-resistant pharmaceutical package under 16 CFR 1700?
- Press-and-turn cap (Correct answer)
- Snap cap
- Flip-top dispensing closure
- Standard screw cap
Correct answer: Press-and-turn cap
Press-and-turn caps are the most common child-resistant closure meeting CPSC requirements under 16 CFR 1700.
Question 5: What is the key difference between low-density polyethylene (LDPE) and high-density polyethylene (HDPE) in packaging applications?
- LDPE is more rigid; HDPE is more flexible
- HDPE has higher crystallinity and stiffness; LDPE is more flexible (Correct answer)
- LDPE has better oxygen barrier; HDPE has better moisture barrier
- HDPE is transparent; LDPE is opaque
Correct answer: HDPE has higher crystallinity and stiffness; LDPE is more flexible
HDPE has higher crystallinity, resulting in greater stiffness and chemical resistance, while LDPE's branched structure makes it more flexible.
Question 6: Which paperboard grade is most commonly used for folding cartons in food packaging?
- Solid bleached sulfate (SBS) (Correct answer)
- Unbleached kraft board
- Chipboard
- Corrugated medium
Correct answer: Solid bleached sulfate (SBS)
Solid bleached sulfate (SBS) is preferred for food folding cartons due to its brightness, cleanliness, and FDA compliance for food contact.
Question 7: What does the term 'caliper' refer to when measuring packaging materials?
- The weight per unit area
- The thickness of the material (Correct answer)
- The tensile strength at break
- The surface roughness
Correct answer: The thickness of the material
Caliper refers to the thickness of a packaging material, typically measured in points (0.001 inch) or millimeters.
CPE Packaging Materials & Components 2
Which property of a packaging material is measured by the Gurley Hill method?