Jacob John, Andrew J. Ortquist, Mats Thunwall, Patrik A. Roseen
Papers # 2018 Las-Vegas
This study investigates production of crosslinked polyethylene (PEX) pipes using a resin obtained from a renewable resource via twin-screw extruder technology. PEX pipes were extruded using petroleum-based and renewable high-density polyethylene (HDPE) for comparison. Testing using relevant ASTM standards on the new pipes indicates that the PEX pipes meets or exceeds the vigorous requirements described in the standards such as excessive hot/cold pressure tests and Environmental Stress Crack Resistance (ESCR). The study shows that the renewable resin shows potential as a starting material for PEX pipes.
In recent years, innovation has progressed at an unprecedented pace where new technologies demand the use of plastics derived from sustainable resources across various industrial manufacturing processes. Though research in bioplastics and sustainable polymers is making great strides, their growth in the plastics industry is still slower than expected. Crosslinked polyethylene (PEX) pipes continue to gain popularity in plumbing and indoor climate applications around the globe. An approach to increasing the sustainability of PEX pipes is to produce them using high-density polyethylene derived from sustainable resources. In this paper, a method for producing a strong and flexible PEX pipe obtained from resin derived from renewable plant resources is described.
The new resin characteristics and pipe properties were compared to resins derived from petroleum resources. The observed difference in crosslink density was found to correlate with the difference in melt flow index between the resins tested.
Production of sustainable PEX pipes was accomplished via twin-screw extruder technology using UV energy as a method for crosslinking. Testing performed on the new pipes indicates that the pipes produced meet or exceed the requirements set by the vigorous industrial requirements outlined in ASTM standards, such as excessive hot/cold pressure requirements and ESCR tests. Comparison of sustainable PEX pipe performance relative to pipe made with petroleum-derived resources are included in this evaluation.