Packaging Materials & Processes Flashcards
7 cards from real CPT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Packaging Materials & Processes flashcards as text
What is the primary mechanism by which active packaging with oxygen scavengers extends the shelf life of red meat?
Answer: Chemically absorbing residual oxygen in the headspace
Iron-based oxygen scavengers chemically react with and remove residual oxygen from the package headspace, preventing oxidative rancidity and aerobic microbial spoilage.
In HDPE blow molding for bottles, 'parison programming' is used to:
Answer: Vary the parison wall thickness to achieve uniform bottle wall thickness
Parison programming varies the die gap during extrusion to compensate for differential stretching, resulting in more uniform wall thickness in the finished bottle.
Which paper property, measured in grams per square meter (GSM or g/m²), describes the mass per unit area of the sheet?
Answer: Basis weight (grammage)
Grammage (basis weight in metric) is the mass per unit area expressed in g/m², a fundamental specification for all paper and paperboard grades.
What type of label construction is used in 'shrink sleeve' labeling, and what property enables it to conform to container contours?
Answer: Biaxially oriented film with tension-applied heat shrinkage
Shrink sleeve labels are made from biaxially oriented films (typically PETG or OPS) that shrink primarily in the machine direction when heat is applied, conforming to complex shapes.
Which packaging process joins two webs of film by applying heat and pressure along a continuous seam to form pouches or bags?
Answer: Lap sealing on a HFFS machine
Horizontal form-fill-seal (HFFS) machines use heated sealing bars or bands to lap-seal continuous film webs, forming the bottom and side seals of pouches.
What is the primary reason polypropylene (PP) is preferred over polyethylene (PE) for hot-fill packaging applications?
Answer: PP has a higher melting point and heat deflection temperature
PP's higher melting point (~165°C) and heat deflection temperature allow it to withstand the 85-95°C filling temperatures used in hot-fill processes without deforming.
In environmental stress crack resistance (ESCR) testing of HDPE containers, what combination of conditions is being evaluated?
Answer: Simultaneous exposure to a chemical agent and tensile stress
ESCR testing exposes HDPE specimens to a surfactant or chemical agent while under tensile stress, simulating real-world cracking that occurs when detergent bottles contact their contents.