Understanding Types of Plastic

Thursday, March 26, 2015


"BRI"ef: 109 - Packaging Options Direct’s Guide to Understanding Plastic Packaging

Plastic bottles and plastic jars are great for a wide range of products. The convenience, flexibility, safety, and sustainability make the economical containers a smart choice for products ranging from shampoos and weed killers. The added benefits of lightweight portability and being able to recycle most plastic containers makes them a definite packaging contender in the great packaging battle of glass versus plastic. In fact, here are a couple of quick statistics that might blow your mind.

  • 20 billion plastic bottles are produced every year.
  • Plastic bottles generally cost less to ship than glass bottles.

But how do you know which plastic containers are right for your product? With so many types of plastic on the market it can get quite over whelming.  In this “BRI”ef, I am going to give you a quick breakdown on the primary types of plastic, their resin identification, and the primary benefits of each type.

PETE - Polyethylene Terephthalate

Polyethylene Terephthalate – The most useful and widely used plastic and is generally used for cosmetics, pharmaceuticals, carbonated beverages, mouthwashes, and liquors.  PET is often rigid and transparent (or even crystal clear), and has very good oil barrier properties, good alcohol and solvent barrier, and a fair water barrier. PET containers have a 176° Fahrenheit max temperature (204° F for short periods) and a -58° Fahrenheit minimum temperature. Though PET containers are not recommended for autoclave or dry heat sterilization, you can sterilize them with gas, gamma irradiation, or chemical disinfectant sterilization processes.

HDPE - High Density Polyethylene

High Density Polyethylene – Depending on the density of this plastic, it is often more rigid than LDPE, or MDPE plastics; making it most commonly used for detergents, bleaches, syrups, industrial cleaning products, cosmetics, and oils (both industrial and edible).  Milky in color (known in the container industry as “Natural”) HDPE plastics have a higher opacity than LDPE plastics. They are also known to have good impact strength, as well as a good environmental stress crack resistance, and better barrier properties than LDPE plastics.  HDPE bottles have a 230° Fahrenheit max temperature (248° F for short periods) and a -148° Fahrenheit minimum temperature. Though HDPE containers are not recommended for autoclave or dry heat sterilization, you can sterilize them with gas, gamma irradiation, or chemical disinfectant sterilization processes.

V - Polyvinylchloride

Polyvinylchloride – Bottles and jars made of PVC are often hard and rigid; and are transparent but have a blue hue to them. Most commonly they are used for automotive chemicals, cosmetics, personal care products, household chemicals, edible oils, and vinegars. They have a very good resistance to oils and a low permeability to gases. These are not recommended for temperatures in excess of 158° Fahrenheit, but have a low temperature threshold of -13° Fahrenheit. Recommended sterilization processes would be gas or chemical disinfectant. 

Medium Density Polyethylene

Medium Density Polyethylene – Great for squeeze applications, this type of plastic provides intermediate properties between low and high density polyethylene, as it is more rigid than LDPE, but less rigid than HDPE. These bottles are usually milky in color.

LDPE - Low Density Polyethylene

Low Density Polyethylene – Generally used for cosmetics, pharmaceuticals, and personal care products this is the most highly used plastic. LDPE is flexible and milky in color. LDPE containers have high impact strength, so high in fact they are virtually unbreakable.  They have excellent environmental stress crack resistance; and are resistant to many chemicals. The down side to LDPE plastic is that it has a low water and alcohol permeability; so they can be slowly attacked by strong oxidizing agents or solvents which will eventually cause softening or swelling.  LDPE bottles have a 176° Fahrenheit max temperature (204° F for short periods) and a -58° Fahrenheit minimum temperature. Though LDPE containers are not recommended for autoclave or dry heat sterilization, you can sterilize them with gas, gamma irradiation, or chemical disinfectant sterilization processes.

PP - Polypropylene

Polypropylene – More rigid than HDPE plastics, bottles made of PP tend to naturally be more yellowish or gray in color; but can be translucent or even clear depending on exactly how they are made. Most commonly used for pharmaceuticals, cosmetics, syrups, juices, shampoos and more. They have an excellent environmental stress crack resistance, and though properties are generally equal to those of HDPE plastics, PP plastics are also resistant to most chemicals. A major advantage to PP containers is that they have a higher temperature resistance than HDPE containers, a max temperature of 275° Fahrenheit, and a 32° Fahrenheit minimum temperature.  The containers can be sterilized by autoclave, gas, or chemical disinfectant.

PS - Polystyrene

Polystyrene – A hard, rigid, transparent plastic with good dimensional stability makes this plastic great for dry pharmaceuticals, jellies, vitamins, and spices. PS has a good chemical resistance to many aqueous solutions but is soluble in many aromatic or halogenated solvents and could become brittle at lower temperatures. Though the plastic is okay at temperatures of 158° Fahrenheit for short times, it is not generally recommend that they are keep in temperatures in excess of 140° Fahrenheit ; and should not be kept at temperatures below -40° Fahrenheit. Gas sterilization or gamma irradiation sterilization processes are most recommended for containers made of PS plastic.

Check out and download our Plastic Comparison Chart below to easily compare types of plastics; and read some of my previous “BRI”efs for more helpful information on choosing your packaging. I hope you join me next time, and as always, I am happy to help any time our valued customers have questions. Please feel free to email us, or call us at (855) 754-3728 if you should ever need assistance with choosing the correct product for your specific needs. Should you have any questions about this blog, or ideas for future please email me at brianne.livas@packagingoptionsdirect.com, and type BLOG TOPIC in the subject line.

Click Here to Download the Plastic Comparison Chart

 

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Comments

  • Sara

    3/27/2015 1:25 PM
    This is super helpful information, I get questions all the time about these, and now I have a place to direct them. Thanks!

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