CPT Packaging Materials & Processes 2

Question 1

Which polymer property is most critical when selecting a film for retort packaging that must withstand 121°C sterilization?

Accepted Answer

High heat deflection temperature

Answer

High heat deflection temperature ensures the film maintains structural integrity during high-temperature retort sterilization cycles.

Question 2

In blown film extrusion, the blow-up ratio (BUR) primarily affects which film property?

Accepted Answer

Transverse direction tensile strength

Answer

A higher blow-up ratio stretches the film in the transverse direction, increasing molecular orientation and tensile strength in that direction.

Question 3

What is the primary function of an ethylene vinyl alcohol (EVOH) layer in a multilayer flexible packaging structure?

Accepted Answer

Oxygen barrier

Answer

EVOH provides exceptional oxygen barrier properties, preventing oxidation of oxygen-sensitive products like meat and snack foods.

Question 4

Which corrugated board flute size offers the best cushioning for heavy industrial products?

Accepted Answer

A-flute

Answer

A-flute has the tallest flute height (~4.8mm), providing maximum cushioning and stacking strength for heavy industrial goods.

Question 5

During thermoforming, what defect occurs when the heated sheet contacts the cold mold too quickly before fully stretching?

Accepted Answer

Webbing

Answer

Webbing occurs when excess material folds onto itself between the mold cavities because the sheet is not stretched uniformly before forming.

(CPT) Certified Packaging Technologist Practice Test