Performance of Low Temperature Curing EPDM Extruded Profiles for Weatherstrip Applications
|Date Published||September 7, 2011|
This paper aims to demonstrate the feasibility and benefits of using rubber compounds that can be cured at lower temperatures than are currently used for EPDM extruded profiles for automotive weatherstrip. The basic cure properties of an LTC compound are compared with a conventionally cured control weatherstrip EPDM compound. The relative cure rate of the LTC compound is about 2 times faster than the control at 190ºC and this difference increases for lower cure temperatures to more than 300 times faster at 100ºC. The extrusion performance of an LTC compound was confirmed on an NFM Iddon High Intensity Mixing scroll extruder with a Garvey die where perfect profile shapes were obtained. Energy consumption comparisons were made with a conventional compound extruded at normal temperatures at different scroll speeds. When processed at low temperature the LTC compound gave similar energy consumption to the control with a 15% lower production rate. When processed at normal temperature the LTC compound required 20 – 26% less energy than the control with a 10% lower production rate. During the cure stage, because of the greater reactivity of the LTC compound, an energy saving on heating of 30% or more is shown to be feasible. Controlled cure of test sheets was achieved using the cure-control package CURIGHT, which uses a cure units approach to account for variations in temperature profile.