A plastic’s gas barrier or WVTR (water vapor transmission rate) is measured in g-mil/100in 2/24hr, indicating the penetration of vaporized H2) through the plastic barrier. PET plastics have a WVTR of 2.0 2hile HDPE plastics have a WVTR of 0.5. When you have a lower WVTR that means the packaging type will protect its contents against moisture exposure for a longer period.
When needing to ship hazardous goods that require a hazmat box and accurate labeling, ensure your plastic packaging choice complies with the necessary WVTR for barrier performance.
Even though both PET and HDPE are recyclable plastics they need to be separated before recycling because they require different processes that breakdown their contents.
When you look at the base of each type of plastic, there will be a triangular label with a number inside of it. This number shows you the recycle rating. PET has a recycle rating of 1, while HDPE has a recycle rating of 2.
Plastics with a 1 rating are intended for a single use only, as heating and reusing these items can cause antimony to leech from the plastic. They are accepted by most U.S. jurisdictions and are easily recycled by shredding them into pallets.
Plastics with a 2 rating have a high strength-to-density ration meaning they are suitable for reuse and recycling. HDPE plastics can be recycled up to 10 times before disposal. Plastics with a 2 rating are often re-molded into pipes, lumber, toys, and floor tiles.