Experimental and modelling study of superficial elastomer vulcanization by short wave infrared radiation

During the manufacturing of car body joints, many thermal processes are usually used to obtain the end product. Among these processes, infrared technology is widely employed, notably at the extruder outlet in order to quickly vulcanize superficially the elastomer. The extruded profile is next totally vulcanized during the process continuation. This superficial treatment is a major process step because it fixes the extruded product section and prevents thus shape deformations. A perfect knowledge of the infrared impact is necessary to provide a good quality of the end product. This paper deals with the study of superficial vulcanization of an EPDM-based rubber by infrared radiation. Thermo-physical properties and reaction kinetics were estimated by experimental measurements. A numerical model was developed to predict temperature and vulcanization profiles in the material thickness. In parallel, vulcanization tests were carried out on instrumented samples. The simulated temperature profiles were compared and validated with experimental ones and a new experimental methodology was implemented to determine and to validate the vulcanization profile in the sample thickness.