Plastics Comparison Chart
The following chart compares characteristics for the most common types of resins used for plastic packaging. However, most data refers to tests done on sheets of resin (film) rather than rigid plastic bottles. For best results, Alpha Packaging recommends that our customers always test their product in actual bottles to ensure compatibility.
|Material||Clarity||MVTR*||O2**||CO2**||Impact Strength||Recycle Code|
|PET (Oriented or Stretch Blown Polyethylene Terephthalate)||Excellent||2.0||75||540||Good||1|
|HDPE (High Density Polyethylene)||Poor||0.5||4,000||18,000||Good||2|
|PVC (Polyvinyl Chloride)||Good||3.0||150||380||Fair||3|
|PLA (Polylactide – Oriented/Stretch Blown bottles)||Very Good||18-22||38-42||201||Good||7|
*MVTR stands for Moisture Vapor Transmission Rate in g-mil/100in. 2/24hr. MVTR is a measure of the passage of gaseous H2O through a barrier. The lower the rate, the longer the package protects its contents from moisture and ensures the moisture content of the product remains the same.
**O2 and CO2 stand for Oxygen Transmission Rate (OTR) and Carbon Dioxide Transmission Rate (COTR) in cm3-mil/m2/24hr. OTR and COTR are measures of the amount of gas that passes through a substance over a given period. The lower the readings, the more resistant the plastic is to letting gasses through.
Plastic Material Definitions
Polyethylene Terephthalate (PET)
Polyethylene Terephthalate is a strong, lightweight plastic resin and form of polyester that closely resembles glass in clarity and takes colorants well. PET is commonly used in food packaging due to its strong barrier properties against water vapor, dilute acids, gases, oils and alcohols. PET is also shatter-resistant, slightly flexible and easy to recycle.
High Density Polyethylene (HDPE)
High Density Polyethylene is a rigid, tough and strong resin of natural milky color. HDPE has very good stress crack resistance as well as high impact and melt strength. HDPE is appropriate for personal care, beverages, food and chemicals. It lends itself particularly well to blow molding.
Polyvinyl Chloride (PVC)
Polyvinyl Chloride is a widely-used plastic. PVC containers offer clarity, durability and chemical resistance. They are primarily used for household goods such as soaps and cleaners, chemicals and personal care items. The material is often used for pipelines in the water and sewer industries because of its inexpensive nature and flexibility.
Polypropylene is a thermoplastic polymer used in a wide variety of applications, including food packaging, textiles, laboratory equipment, automotive components, and polymer banknotes. It is unusually resistant to many chemical solvents, bases and acids. It is much less brittle than HDPE. Polypropylene has very good resistance to fatigue, so that most plastic living hinges, such as those on flip-top bottles (Tic Tacs), are made from this material.
Polystyrene comes in many shapes and forms, from foam egg cartons and meat trays, to soup bowls and salad boxes. It protects against moisture and maintains its strength and shape even after long periods of time.
Polylactide is a corn-based resin made by NatureWorks® PLA that requires significantly less energy to mold into plastic containers. It can be shaped into a variety of bottles, containers, trays, film and other packaging. The production of PLA uses 68 percent less fossil fuel resources than traditional plastics and it is the world's first greenhouse-gas-neutral polymer. The properties of PLA are well suited for the injection stretch blow molding process used to form bottles and jars. PLA is primarily suited for short-shelf-life applications that use cold-filling techniques. It is successful as a bottle resin because of its transparency and its fit with all landfill diversion options.