Plastic Technologies Launches Free App to Calculate Intrinsic Viscosity for PET Blends

Holland, Ohio (November 8, 2011) —Plastic Technologies, Inc. (PTI) has launched a new free app which calculates the intrinsic viscosity (IV) of polyethylene terephthalate (PET) resin blends via a two-step process.  Called the PET Blend Calculator, the app is available on iPhone/iPad and Android platforms.

“Virgin and recycled PET (rPET) have different IVs. As the use of rPET for packaging containers continues to grow, the need for a quick way to calculate the blend’s IV is also increasing. We created this calculator app so that processors can easily get to the correct IV number via a hand-held device,” said Scott Steele, vice president international operations, PTI.

The first screen asks the user to plug in the volume percentage and IV for each of the two resins. By tapping the screen’s “submit” button, the new IV—as well as the molecular weight for each of the resins and the final blend—is displayed.

Once that calculation is complete, the user is directed to a second screen (a PET Hydrolytic Degradation Nomograph) to input moisture information (percentage of moisture/parts per million).

The blend IV number has been transferred over from the first screen and is plotted on a vertical column on the left.  The user inputs moisture percentage by sliding a plot point on a vertical scale on the right to the appropriate value.  (The two plot points are tethered by a moveable line.)   The intersection of that line, on a third vertical plane located in the middle of the two, is the blended material’s final IV.

“We wanted to create a tool that was free, portable and easy-to-use.  PTI’s PET Blend Calculator computes the final IV in a couple of seconds.  The visual reference points are easy to plot and read.  It has the potential to save companies significant money by removing the guesswork out of determining the correct final IV.  In turn, this minimizes the chance of producing underperforming preforms, bottles and thermoforms,” Steele said.

The PET Blend Calculator is an ideal tool for plastic processors, resin producers, lab techs, plant production, equipment manufacturers and others involved in the PET process.  It can be quickly located in the iTunes App Store or the Android Market by searching for “PET Blend Calculator.”

This release follows the app PTI launched earlier in the year—a standalone PET Hydrolytic Degradation Nomograph.

About Plastic Technologies

Plastic Technologies, Inc. (PTI) is recognized worldwide as the preferred source for preform and package design, package development, rapid prototyping, pre-production prototyping, and material evaluation engineering for the plastic packaging industry. For more info: