Common Packaging Materials
Bottles and jars may look similar, but the materials used to manufacture them can be very different.
Packaging materials influence a container's appearance, flexibility, weight, performance, and suitability for different products.
In this lesson, we'll introduce commonly used plastic resins and glass packaging.
A resin is a raw material used to manufacture plastic packaging. Different resins have different properties that influence how a container looks and performs.
Many packaging resins are identified by abbreviations such as PET, HDPE, LDPE, and PP.
Learning these abbreviations is a useful first step toward understanding plastic packaging options.
Five Common Plastic Resins
These materials are used across a variety of consumer, industrial, healthcare, and specialty packaging applications.
PET
Polyethylene TerephthalateAppearance: Commonly clear, although colored and opaque versions are available.
Characteristics: Lightweight, relatively rigid, and capable of excellent clarity.
Applications: Beverages, personal care, household products, and other selected liquid packaging.
Remember: PET is often considered when a clear, glass-like appearance is desired.
HDPE
High-Density PolyethyleneAppearance: Often natural translucent or opaque, and available in various colors.
Characteristics: Durable, lightweight, and commonly used for blow-molded bottles.
Applications: Detergents, household cleaners, automotive fluids, personal care, and industrial products.
Remember: HDPE is widely used in rigid plastic bottles.
LDPE
Low-Density PolyethyleneAppearance: Often translucent or opaque.
Characteristics: Generally more flexible and squeezable than HDPE.
Applications: Squeeze bottles, dispensing containers, and flexible packaging components.
Remember: LDPE is useful to recognize when discussing squeezable packaging.
PP
PolypropyleneAppearance: Available in translucent or opaque forms and various colors.
Characteristics: Lightweight and commonly selected for molded packaging components.
Applications: Caps, closures, jars, dispensing components, and certain bottles.
Remember: PP is especially common in closures and jars.
PVC
Polyvinyl ChlorideAppearance: Can be clear or colored.
Characteristics: Can be formulated as a rigid plastic material.
Applications: Selected specialty containers and specific rigid packaging designs.
Remember: PVC may be found in some existing bottle designs, but its suitability and end-of-life considerations require evaluation.
A clear bottle is not automatically PET. An opaque bottle is not automatically HDPE.
Color and appearance alone are not reliable ways to determine material. Always check the packaging specifications or confirm the material with the manufacturer.
Some packaging uses post-consumer recycled (PCR) material.
We'll explain PCR, resin identification codes, and other sustainability concepts in Lesson 7.
Understanding Glass Packaging
Not all rigid packaging is plastic. Glass is another commonly used container material.
Appearance
Glass can provide a clear, premium appearance and is also available in colors such as amber and green.
Characteristics
Glass is rigid, typically heavier than plastic, and generally offers strong barrier properties.
It is also breakable, so handling and transportation matter.
Applications
Glass is used for fragrances, cosmetics, essential oils, pharmaceuticals, food products, and other selected applications.
Neither material is automatically the right choice for every product.
A customer may prefer glass for its appearance or barrier characteristics, while plastic may offer advantages in package weight, impact resistance, or design flexibility.
Selection depends on the specific product and packaging requirements.
Comparing Common Packaging Materials
Use this chart as a starting point for recognizing general material characteristics.
| Material | Common Characteristic | Typical Packaging Examples |
|---|---|---|
| PET | Often clear and relatively rigid | Clear bottles and consumer packaging |
| HDPE | Durable, lightweight, often opaque | Detergent and industrial bottles |
| LDPE | Flexible and squeezable | Squeeze bottles and dispensers |
| PP | Common in molded components | Caps, closures, jars and bottles |
| PVC | Can be made into rigid containers | Selected specialty bottles |
| Glass | Rigid, often clear, breakable | Fragrance, cosmetic and specialty containers |
These are general material descriptions, not compatibility approvals.
Properties vary by resin grade, bottle design, additives, manufacturing process, and other factors.
How Do You Choose a Packaging Material?
The right material depends on what the package needs to accomplish.
Five Important Questions
- What is the product? The contents and formulation influence material selection.
- What appearance is desired? Does the customer prefer clear, natural, opaque, or colored packaging?
- How will the package be used? Does it need to be squeezed, sprayed, poured, or pumped?
- How will the package be filled? Filling temperature, equipment, and process requirements can affect material selection.
- What other requirements apply? Consider storage, transportation, sustainability, and applicable regulatory needs.
Real-World Example: A Household Cleaner
Imagine a customer requests a new bottle for a household cleaning product.
HDPE may be one material worth considering because it is commonly used for household products.
However, the cleaner's actual ingredients, concentration, storage conditions, dispensing system, and intended use must be evaluated.
The takeaway: A material commonly used in an industry is not automatically compatible with every product in that industry.
When a customer asks for a specific resin, find out why they need that material.
They may be trying to meet a performance requirement, achieve a certain look, match existing packaging, or satisfy a sustainability goal.
Understanding the reason helps determine what should be evaluated.
What You've Learned
Knowing the names and general characteristics of common packaging materials helps you participate in packaging discussions with greater confidence.
Six Things to Remember
- PET is often selected when clarity is important.
- HDPE is widely used for household, industrial, and personal care bottles.
- LDPE is generally more flexible and squeezable.
- PP is common in closures, jars, and other packaging components.
- PVC and glass are additional materials found in selected rigid packaging applications.
- Material selection must be based on actual product requirements and compatibility evaluation.
In Lesson 7, we'll introduce post-consumer recycled (PCR) materials, resin identification codes, lightweighting, and other packaging sustainability concepts.
You'll also learn why a recycling code does not guarantee a package will be accepted by every recycling program.