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Questions and Answers
Which of the following is a property of EVOH (ethylene vinyl alcohol)?
Which of the following is a property of EVOH (ethylene vinyl alcohol)?
PVC (polyvinyl chloride) is primarily used for transparent films and containers.
PVC (polyvinyl chloride) is primarily used for transparent films and containers.
True
What type of packaging product is typically made from nylon (polyamide)?
What type of packaging product is typically made from nylon (polyamide)?
Pouches or thermoplastics
___ is a commercial name for polyvinylidene chloride.
___ is a commercial name for polyvinylidene chloride.
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Match the following materials to their common uses:
Match the following materials to their common uses:
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Which polymer is characterized by good tensile strength and impact strength?
Which polymer is characterized by good tensile strength and impact strength?
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LLDPE is noted for its high melting point and is often used in soft drink bottles.
LLDPE is noted for its high melting point and is often used in soft drink bottles.
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___ is blended with gas to achieve low density and opaque labels.
___ is blended with gas to achieve low density and opaque labels.
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Which type of polyethylene is solid at ambient temperatures?
Which type of polyethylene is solid at ambient temperatures?
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LDPE has a higher impact and puncture resistance than LLDPE.
LDPE has a higher impact and puncture resistance than LLDPE.
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What are two characteristics that can be modified in LLDPE?
What are two characteristics that can be modified in LLDPE?
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PP stands for ______.
PP stands for ______.
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Match the following materials with their properties:
Match the following materials with their properties:
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Which trade name is associated with Polymethyl pentene?
Which trade name is associated with Polymethyl pentene?
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High nitrile polymers (HNP) are known for their excellent flavor and aroma protection due to their nitrogen content.
High nitrile polymers (HNP) are known for their excellent flavor and aroma protection due to their nitrogen content.
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What is the primary use of Polymethyl pentene?
What is the primary use of Polymethyl pentene?
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Fluoropolymers are also known as __________.
Fluoropolymers are also known as __________.
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Match the following polymers with their characteristics:
Match the following polymers with their characteristics:
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What is a key feature of polyethylene naphthalene dicarboxylate (PEN) compared to PET?
What is a key feature of polyethylene naphthalene dicarboxylate (PEN) compared to PET?
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Polytetrafluoroethylene (PTFE) has a low melting point, making it unsuitable for high-temperature applications.
Polytetrafluoroethylene (PTFE) has a low melting point, making it unsuitable for high-temperature applications.
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What are two common uses for Barex?
What are two common uses for Barex?
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What is the primary trade name for polyvinylidene chloride?
What is the primary trade name for polyvinylidene chloride?
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PVDC films are often used alone without additional layers for packaging.
PVDC films are often used alone without additional layers for packaging.
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What is a common use of plasticized PVC films?
What is a common use of plasticized PVC films?
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What is the primary advantage of using ethylene vinyl alcohol copolymer (EVOH) in packaging?
What is the primary advantage of using ethylene vinyl alcohol copolymer (EVOH) in packaging?
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Polystyrene has excellent clarity but a low gas barrier.
Polystyrene has excellent clarity but a low gas barrier.
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PVDC is known for its excellent __________ and moisture barriers.
PVDC is known for its excellent __________ and moisture barriers.
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What is the melting temperature of polypropylene?
What is the melting temperature of polypropylene?
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Expanded polystyrene (EPS) is used to make ______ containers for food.
Expanded polystyrene (EPS) is used to make ______ containers for food.
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Which material is considered the most expensive of all commonly used packaging polymers?
Which material is considered the most expensive of all commonly used packaging polymers?
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Match the types of plastics with their characteristics:
Match the types of plastics with their characteristics:
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What significant feature allows ionomers to have faster packaging line speeds?
What significant feature allows ionomers to have faster packaging line speeds?
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Which characteristic does high impact polystyrene (HIPS) exhibit compared to standard polystyrene?
Which characteristic does high impact polystyrene (HIPS) exhibit compared to standard polystyrene?
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Polypropylene is less suitable for hot filling applications than polyethylene.
Polypropylene is less suitable for hot filling applications than polyethylene.
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EVA stands for __________ vinyl acetate.
EVA stands for __________ vinyl acetate.
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What is a major concern associated with the use of expanded polystyrene (EPS)?
What is a major concern associated with the use of expanded polystyrene (EPS)?
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Which of the following is a common use for EVA-based hot-melts?
Which of the following is a common use for EVA-based hot-melts?
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Nylon 6 is synthesized using adipic acid and hexamethylene diamine.
Nylon 6 is synthesized using adipic acid and hexamethylene diamine.
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What are the two most common types of Nylon mentioned?
What are the two most common types of Nylon mentioned?
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Polycarbonate can withstand temperatures above _____ degrees Celsius.
Polycarbonate can withstand temperatures above _____ degrees Celsius.
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Which material is suspected to be an endocrine disruptor?
Which material is suspected to be an endocrine disruptor?
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Styrene butadiene co-polymer has high permeability to water vapor and gases.
Styrene butadiene co-polymer has high permeability to water vapor and gases.
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What does SB stand for in the context of polymers?
What does SB stand for in the context of polymers?
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Study Notes
Packaging Materials
- Diverse materials used in packaging, each with unique properties.
- Key properties of paper and paperboard: Low-density materials, poor barriers to light (unless coated), poor barriers to liquids, gases and vapors, grease resistant, good stiffness, crease/fold/glue ability, tear easily, not brittle, excellent substrates for inexpensive printing.
- Key properties of plastics: Wide range of barrier properties, permeable to varying degrees of gases and vapors, low density materials, variable tensile and tear strengths, functional over a wide range of temperatures, low stiffness, flexible.
- Plastic packaging: Thermoplastic, i.e. reversibly fluid at high temperatures. Characteristics modified by co-polymerization, blending, additives, alloying, surface treatment.
Paper Packaging
- Cellulose fibers: strength and mechanical properties vary depending on the fiber sources and processing treatment; additives, surface coatings, and laminations used to modify properties.
- Primary or secondary packaging: includes paperboard folding cartons, composite paperboard cans (laminated paperboard), distribution cases.
Plastic Packaging Types
- LDPE (low-density polyethylene): slightly cloudy, high tensile strength, good moisture barrier properties, high gas permeability. Used for shrink and stretch bundling, pallet wrapping, packaging of bread, fresh vegetables, fruit, and stable food products.
- LLDPE (linear low-density polyethylene): higher tensile and elongation at break; higher heat-seal temperature; higher impact and puncture resistance than LDPE; similar moisture and gas-barrier properties to LDPE as LDPE.
- HDPE (high-density polyethylene): more translucent, stiffer, higher gas and moisture permeability than LDPE; high melting point. Used for bottles.
- PP (polypropylene): excellent water vapor barrier, medium gas barrier, excellent clarity; good heat-seal properties; often oriented – improved heat resistance and other physical properties. Heat-set (packaging bakery products, pouches); non-heat-set (transparent, moisture barrier enhancing aesthetic appeal); coating, vacuum metallization.
- PVC (polyvinyl chloride): transparent, soft, high gas permeation, low water vapor transmission. Used for packaging fresh red meat, poultry, and vegetables. Plasticized PVC films are limp, tacky (slightly sticky), stretchable.
Other Packaging Materials
- Cellophane: transparent, protection against oxygen and aroma, wrinkle resistance, stiff. Coated to be moisture proof.
- PET (polyethylene terephthalate): Good gas and water vapor properties, very high tensile and impact strengths. Properties improved with coating or metallization. Used in soft drink bottles and vacuum-metallized films.
- Nylon (polyamide): Good oxygen barrier, tough, thermoformable; fair moisture barrier; high melting point; chemical resistance. Lamination with other materials can improve properties.
- Polystyrene (PS): Amorphous polymer with excellent clarity. Used as films (windows in paperboard boxes), solid PS (clear, low gas barrier, hard, low impact strength); expanded polystyrene (EPS) for cups, bowls, plates, meat trays, clamshell containers, egg cartons.
- High Impact Polystyrene (HIPS): An immiscible blend of polystyrene, polybutadiene, and grafted polystyrene-polybutadiene copolymer. More resilient and impact resistant than standard PS.
- Polyvinylidene chloride (PVDC): Trade name Saran, copolymer of vinylidene chloride and vinyl chloride; excellent oxygen and moisture barriers; used in films, containers, coatings; monolayer (household wraps); multilayer films (packaging food that requires good oxygen barrier); used co-extruded with polyolefins in shrinkable films; for tight closure of meat and cheese products.
- Ethylene vinyl alcohol copolymer (EVOH): Crystalline copolymer of ethylene and vinyl alcohol; exceptional high oxygen barrier in multilayer structures; laminated or coextruded with other polymer layers to form barrier layers; more expensive among packaging polymers.
- Ionomer: Trade name Surlyn, contains small but significant portion of ionic units; chemical structure: nonpolar ethylene groups, polar methacrylic acid group, carboxylate ionic pairs; good sealing performance, formability, clarity, and oil/grease resistance. The ionic crosslinks reversibly diminish with heating, enabling the polymer chains to move.
- Ethylene vinyl acetate (EVA): High versatility in hot-melt formulations used for packaging, bookbinding, label sticking, glue sticks; EVA resins for packaging film, heavy duty bags, extrusion coating, wire and cable jacketing; hot melt adhesives; cross-linked foam; and as a lidding sealing layer, used in applications with PE, PP, PET, and PS.
- Polyamides (Nylons): amide groups (-CO-NH-) in the backbone chain. Common types: nylon 6,6 and nylon 6. Nylon 6 synthesized using monomer caprolactam; Nylon 6,6 synthesized using adipic acid and hexamethylene diamine. Nylon has good gas barrier, puncture resistance, and heat resistance.
- Polycarbonate (PC): Amorphous thermoplastics; injection, blow-molded, thermoformed; Good replacement of glass (clear & tough, but lighter); withstands temperatures above 200 °C; used in 5-gallon reusable water bottles.
- Styrene butadiene (SB): Co-polymer; tough, transparent, high-gloss surface finish; relatively low density; high permeability to water vapor and gases, ideal for fresh produce packaging; used in blow-molded food and confectionery containers.
- Acrylonitrile butadiene styrene (ABS): Copolymer of acrylonitrile, butadiene, and styrene; varied properties by altering the monomers' proportions; tough, good impact strength; good tensile strength; flexing properties, can be either translucent or opaque; thermoformable; and can be molded. In large shipping and storage containers, and thin-walled margarine tubs and lids.
- Polymethyl pentene (PMP): Co-polymer methyl pentene; Low density; clear; heat resistant up to 200°C; excellent transparency and gloss; used as trays, extrusion coating on paperboard, in baking applications.
- High nitrile polymers (HNP): Co-polymers acrylonitrile, good gas and odor barrier properties; good flavor protection; chemical resistance; clear, tough, rigid; used as inner layer in blow-molded bottles with HDPE; can be film/sheet/laminated with PE, PP, and foil for flexible packaging.
- Fluoropolymers: related to ethylene; High performance, highest water vapor barrier, highest gas barrier; high resistance to chemicals at low temperatures; transparent, heat sealable, can be laminated, thermoformed, metalized, and sterilized; used for blister packs, laminated with PVC; expensive.
- Polyethylene naphthalene dicarboxylate (PEN): Relatively new condensation polymer; higher gas and water vapor barrier and strength compared to PET; UV resistant and has higher temperature resistance; used in one-trip beer/soft drink bottles, returnable/refillable beer/mineral bottles.
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Description
Test your knowledge on the properties and uses of various polymers such as EVOH, PVC, and nylon. This quiz covers key characteristics, applications, and trade names associated with different types of plastics. Ideal for students studying materials science or related fields.
