New RTPOs for Mid-Wall Thickness Bumper Fascias

摘要

Since the late 1980s, reactor grade TPOs (RTPOs) have gained wide acceptance in the automotive fascia market segment as reliable and cost effective contributors to the overall bumper system. As demands have changed over the years, so have RTPOs. This paper describes the evolution of RTPO grades from conventional, ～7 dg/min melt flow rate (MFR), medium flexural modulus (500 MPa) resins, to ～20 MFR, 950 MPa flexural modulus grades. The newer, high flow grades exhibit excellent moldfilling characteristics, a very favorable impact/stiffness balance, and very good low temperature ductility. Additionally, they demonstrate exceptional paintability as evidenced by very well balanced paint adhesion, durability, and ductility. Based on their desirable property profiles and excellent processing characteristics, these new RTPOs become ideal candidates for lightweight, mid-wall (～2.8 mm) bumper fascia applications.