Study of Adhesion Force of Silicone Coated PA 6,6 Fabric

In this study, the adhesion mechanism of three commercial two-component room temperature vulcanizing silicone rubber samples to polyamide 6,6 airbag fabric is investigated and a test method is designed to evaluate the adhesion force. The results of this test reveal the separation resistance of the two surfaces by determining the force required to initiate the separation. Two components of the silicone samples were combined and the mixtures were coated on PA 6,6 fabric. Then the curing reactions have occurred at 160, 180 and 200 °C temperatures for 5, 7 and 10 minutes. In order to determine and compare the adhesion force of silicone samples to airbag fabric, a test method was designed to measure the force required to remove silicone coating from the surface of the fabric. To simulate the normal force mechanism applied to the inner coating layer of the airbag during inflation, the normal tensile force was applied by the CRE method to an element with a dimension of 5 × 20 mm. In addition, to evaluate thepeeling force, a T-Peel test according to ASTM D 1876 was performed. Both tests results revealed that by increasing the temperature and curing time parameters, this value increases. In addition, the results of the FTIR test and assignment of the observed peaks, reveal that the silicone sample in which Si-H groups are still available after curing reaction, has a higher adhesion force to PA 6,6 as this force could be caused by the interaction between the hydrogen-bonded silicon atom of silicone with the nitrogen of the amide group in polyamide 6,6. Therefore, the lower crosslink degree causes less silicone adhesion.