CPT Quality Control & Testing 3 — Questions and Answers
Question 1: Which instrument measures the coefficient of friction (COF) between packaging film surfaces?
- Tensile tester with COF sled (Correct answer)
- Shore durometer
- Elmendorf tear tester
- Gurley densometer
Correct answer: Tensile tester with COF sled
A tensile tester fitted with a COF sled drags one film surface across another to measure static and kinetic friction.
Question 2: What does MVTR stand for in packaging testing?
- Moisture Vapor Transmission Rate (Correct answer)
- Material Volume Transfer Ratio
- Minimum Viable Tensile Resistance
- Maximum Vacuum Test Reading
Correct answer: Moisture Vapor Transmission Rate
MVTR (Moisture Vapor Transmission Rate) measures how much water vapor passes through a packaging material over time.
Question 3: A six-sigma process has a defect rate of approximately:
- 1,000 PPM
- 66,807 PPM
- 3.4 PPM (Correct answer)
- 233 PPM
Correct answer: 3.4 PPM
A true six-sigma process produces only 3.4 defects per million opportunities, accounting for a 1.5-sigma shift.
Question 4: Which test evaluates a bottle's resistance to internal pressure bursting?
- Top load test
- Hydrostatic burst test (Correct answer)
- Vacuum leak test
- Drop impact test
Correct answer: Hydrostatic burst test
The hydrostatic burst test pressurizes containers with water until failure, measuring the burst pressure.
Question 5: In packaging quality, a 'critical defect' is best described as:
- A cosmetic blemish affecting appearance only
- A defect likely to cause product loss or customer dissatisfaction
- A defect rendering the unit completely unusable or causing safety hazard (Correct answer)
- A minor dimensional deviation within specification
Correct answer: A defect rendering the unit completely unusable or causing safety hazard
Critical defects are those that may cause safety hazards or complete unit failure, requiring zero acceptance in sampling plans.
Question 6: What does the Elmendorf tear tester measure?
- Seal strength of laminated films
- Force required to propagate a tear in flexible materials (Correct answer)
- Coefficient of friction between layers
- Oxygen transmission rate
Correct answer: Force required to propagate a tear in flexible materials
The Elmendorf tear tester measures the energy required to continue a tear through a pre-cut film or paper specimen.
Question 7: Which quality tool is used to identify the vital few causes responsible for most defects?
- Histogram
- Pareto chart (Correct answer)
- Scatter diagram
- Run chart
Correct answer: Pareto chart
A Pareto chart ranks causes by frequency to identify the vital few (typically 20%) responsible for the majority (80%) of defects.
CPT Quality Control & Testing 3
Which instrument measures the coefficient of friction (COF) between packaging film surfaces?