The CPRR staff hypothesized that the addition of PS to the NJCT mixture, which is largely PE, would enhance the mechanical properties of the post-consumer commingled plastics.
In some of the experiments, the CPRR combined repelletized PS foam plant regrind with the NJCT mixtures.
To study the properties and processing of commingled plastic waste, the CPRR obtained a low-pressure molding unit, the ET/1 extrusion molding machine, from Advanced Recycling Technology, Ltd.
s expanded PS recycling (regrind) operation and densified prior to shipping to the CPRR.
Thus, the CPRR decided that to directly compare feedstock variations only, it would use only samples obtained from the center regions of the profile for property measurements.
The CPRR performed compression tests on an MTS model 810 mechanical tester.
The CPRR determined each sample's compressive modulus from the slope of the best-fit straight line through the first few points of the stress-strain diagrams.
The CPRR found that the addition of PS to the NJCT mixture dramatically increased the mechanical properties of the commingled product.
The CPRR plans to examine the 25%-to-50% range of PS composition in future research.