Plastic is a very important material in the packaging industry, and it comes in a variety of types. In fact, plastics are said to have so many types that it is said to be more than a thousand types.
But despite the numerous types of plastics out there, they are generally classified into 7 categories; 6 for different specific plastics, and one to include all other types.
These are:
Polyethylene Terephthalate - PET or PETE
High-Density Polyethylene - HDPE or PE-HD
Polyvinyl Chloride - PVC or V
Low-Density Polyethylene - LDPE or PE-LD
Polypropylene - PP
Polystyrene - PS
Other or O
Now, let's break down all 7 types of plastic resins.
What is PET plastic – Polyethylene Terephthalate?
Also called PETE plastic, it is a type of plastic that is well loved and used in the packaging world. It is identified by Resin Identification Code 1. It is referred to as Polyester when used for fibers or fabrics; otherwise, it is known as PET or PETE.
Properties of Polyethylene Terephthalate
Polyethylene Terephthalate has several features and mentioning all of them is pretty difficult. Those features include the following:
It is a semi-crystalline plastic
It is colorless
It is resistant to water
It is a thermoplastic, but some variants are thermoset.
It is lightweight
It is a strong plastic resin
It resistants acid chemicals
It is transparent
It is resistant to creep
It is impermeable to CO2
It is shatterproof
It is resistant to cold
It possesses a high strength-to-weight ratio
It has a good adhesion ability
It has a good wielding ability
It has low sliding friction and sliding wear
It has high rigidity and hardness
It is resistant to moisture
It is cheap and readily available
It is malleable
It is an inert material that doesn’t react with food products
It resists attack by micro-organisms
It has good electrical insulation
Uses of PET plastic in packaging
PET is applied in packaging products in several ways; these include:
Water bottles
Soft drink bottles
Bakery trays
Fruit juice containers
Cookie trays
Cooking oil bottles
Butter containers
Vegetable oil bottles
Sports drinks bottles
Honey jars
Ice cube trays
Salad dressings packaging
Liquid hand soap bottle
Mouthwash bottles
Mineral water bottles
Personal care items packaging
Special-Grade PET plastic used for take-out containers
Special-Grade PET plastic used food trays that can be warmed in the oven or microwave
Household cleaners packaging
Soda bottles
Jelly containers
Peanut butter jars
Pickles jars
Is PET plastic safe?
Yes. It has been declared safe for food contact by FDA. But there is some concern among some scientists that when exposed to high temperatures, it may leak low concentrations of a chemical known as Antimony.
Recyclability of PET plastic
Irrespective of what you might have heard, PET is actually very recyclable. In fact, it is currently the most recycled plastic resin.
What is HDPE or PE-HD plastic – High-Density Polyethylene:
This is a tough, but lightweight plastic used to produce several important products that we use daily. It is identified by Resin Identification Code 2.
Properties of HDPE plastic
This plastic resin comes incredibly loaded with features; some of those include:
It is strong
It is lightweight
It resists impact
It lasts really long
It has resistance to weather
It has low transparency
It has little UV resistance
It is susceptible to mold shrinking
It has good electrical insulation
It is malleable
It is mold resistant
It is insect resistant
It is resistant to rot
It is a thermoplastic
It is a semi-crystalline plastic
It is susceptible to stress cracking
Uses of HDPE plastic in packaging
HDPE is widely used in packaging various products; some of those are:
Food
Beverages
Personal care products
Household products
Shampoo
Bread
Grocery
Laundry detergent
Milk
Water
Juice
Margarine
Cottage cheese
Cereal box Liners
Vinegar
Icecream
Cleaning agents
Bleaching agents
Washing and shower soaps
Is HDPE plastic safe?
It is approved as safe by FDA. But there is some concern that under certain conditions, it may release low levels of nonylphenol which may raise estrogen levels.
Recyclability of HDPE plastic
HDPE is a plastic resin that is easily recyclable.
What is PVC or V plastic – Polyvinyl chloride?
This is another widely used plastic, and it is identified by Resin Identification Code 3. It is likely known by many as the plastic pipe that brings in water to houses.
Properties of PVC
PVC has many properties; these include:
It is versatile
It is resistant to abrasion
It is strong
It is resistant to moisture
It does not corrode
It can be easily cleaned
It is resistant to environmental stress
It is resistant to water
It is durable
It has flame resistance due to the abundance of chlorine
Rigid PVC has an outstanding tensile strength
It is very dense
It is cheap
It is readily available.
It is resistant to chemicals
It has poor heat stability which is then countered by adding stabilizers during production.
It emits toxic fumes when it is being melted by fire.
It has excellent organoleptic properties
It has good electrical insulation
It has oxygen barrier properties
It has water barrier properties
It is a thermoplastic material
Uses of PVC in packaging
PVC has many applications in the packaging industry; some of those uses are:
It is used to make shrink wrap
It is used in blister packaging
It is used to package over-the-counter medications
Personal care products packaging
Medicine packaging
Household goods packaging
It is used to make a rigid film
It is used to make cling film
It is used to make plastic closures
Used for packaging disposable syringes
It is used to package medical devices
Batteries packaging
Packaging of electronic parts and accessories
Packaging of Tools
Toys packaging
It is used to package foodstuffs
Toiletries packaging
It is used to make bottle sleeves
It is used to make trays for sweets
Fruit packaging
It is used to make bubble foils
It is used to make food foils
Is PVC plastic safe?
It has been declared safe for food contact by FDA. But there is some concern that in certain conditions, it may leach some dangerous chemicals; hence, it is not the most preferred plastic resin for packaging food.
Recyclability of PVC plastic
PVC is well known to be recyclable.
What is LDPE or PE-LD plastic – Low-Density Polyethylene?
LDPE, also called PE-LD, is a lightweight plastic commonly used in the production of several products. It is identified by Resin Identification Code 4.
Properties of LDPE plastic
Like other plastic resins discussed so far, LDPE is also loaded with features. Some of these features include:
It is strong
It is waterproof
It is chemically resistant
It is tough
It is soft
It has resistance to corrosion
It is compatible with low-temperature.
It is tear resistant
It is transparent
It is thin
It is clear
It is impact resistant
It has poor resistance to halogenated hydrocarbons
It has a weak resistance to mineral oils and oxidizing agents
It has good electrical insulation
It is not useful in extremely high or low temperatures
It has little UV resistance
Uses of LDPE plastic in packaging
LDPE is used in packaging products in a variety of ways; these include:
It is used to make stretch films
It is used to make shrink wraps
Squeezable bottles
Thin container lids
Fruit bags
Frozen food packaging
Grocery bags
Coating for paper milk cartons
Bread bags
Fresh produce bags
Newspaper bags
Plastic bags
Is LDPE plastic safe?
Yes. It has been declared safe for food contact by FDA.
Recyclability of LDPE plastic
LDPE plastics are recyclable, but recycling companies tend to prefer the rigid form of LDPE. The flexible form of LDPE can be complex to recycle.
What is Polypropylene - PP plastic?
Also referred to as PP, this incredibly useful and versatile plastic is said to be like a superhero among other plastic resins. It is identified by Resin Identification Code 5.
Properties of Polypropylene
Polypropylene is incredibly versatile; that can only be possible if it has several useful features that manufacturers are looking for. Some of its features include:
It is translucent
It is cheap
It is elastic
It is tough
It is chemically resistant
It is fatigue resistant
It is a very good insulator
It is normally opaque, but can also be made to be transparent
It doesn't react with water
It doesn’t react with acids
It doesn't react with detergents
It is crack resistant
It has good electrical insulation
It is stress resistant
It withstands wear and tear
It has a relatively slippery surface
It is susceptible to UV degradation
It is difficult to paint due to its poor bonding properties
It is highly flammable
It has poor resistance to chlorinated solvents and aromatics
Uses of Polypropylene in packaging
Polypropylene is incredibly useful in packaging various products. Some of the products that it is used to package are:
Yogurt
Baby food
Medicine
Maple syrup
Cream cheese
Chips
Salad dressing
Margarine
Is Polypropylene safe?
Referred to as superhero plastic, it has been declared safe for food contact by FDA.
Recyclability of Polypropylene
What is the purpose of being a superhero plastic without the ability to be recycled? So of course, Polypropylene is recyclable.
What is Polystyrene - PS plastic?
Also referred to as PS plastic, Polystyrene is a very useful plastic resin used to make a wide variety of products. It is identified by resin identification code 6.
Properties of Polystyrene
Like others, Polystyrene will not allow itself to be outdone by its close family of plastic resins. Some of its features are:
It is clear
It is rigid
It is brittle
It has low heat resistance
It has good electrical insulation
It is inert
It is flammable
It is soluble in chlorine and aromatic solvents
It has good dimensional stability
It has good dielectric strength
It is amorphous in nature
It is malleable
Uses of Polystyrene in packaging
Polystyrene is also widely used in packaging. Some of its applications in packaging are:
TV packaging
CD packaging
Egg cartons
Disposable coffee cups
Bakery trays
Meat packaging
Take-out containers
Styrofoam packing peanuts for shipping
Cosmetic bags
Refrigerator trays
Is Polystyrene safe?
It is approved by FDA by food contact, but there is concern that it can leach low levels of Styrene after a long period of time. The levels released though are very minute and fall way below the FDA-approved limit.
Recyclability of Polystyrene
It is recyclable, but it is not a preferred option for recycling; hence, most recycling centers don’t accept it.
What are Other or O plastics?
This refers to all other plastic resins after the 6 described resins. They are identified by Resin Identification Code 7.
These may include plastics such as:
Polycarbonate PC - 7
Polyamide Nylon
Acrylonitrile Butadiene Styrene ABS
Polyoxymethylene POM
Polyetherimide PEI
Fiberglass
Acrylic
Polylactic Acid - PLA plastic
Melamine
Features of Other or O plastics?
These plastics have varying features, so you will have to identify which one you need to understand its features.
Uses of Other or O plastics in packaging
These plastics all have their own varying applications.
Are Other or O plastics safe?
They are generally approved by FDA; but, you will have to be careful with this category since you don’t know what plastic was used. Some are less toxic than others, while others can be toxic. The ambiguity is what makes this category unwelcome amongst many.
Recyclability of Other or O plastics?
Some of them are recyclable, while some are not. You have to check the recyclability of the specific resin that you need.
Similarities of the plastic resins:
All packaging materials (glass, plastic, metal, paper, etc) contain substances that can leach in tiny amounts into food or beverages.
All plastic resins 1-6 are thermoplastics.
All plastic resins 1-6 are malleable (except the solid form of Polystyrene which is a hard and solid plastic).
All plastic resins 1-6 are relatively cheap compared to other packaging materials.
All plastic resins 1-6 are chemically inert.
All plastic resins 1-6 are good insulators.