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An investigation into polymeric materials for the design of high performances shock tubes
Shock tube initiators are small-diameter hollow plastic tubing used in blasting systems to remotely convey an initiation signal in the form of shock wave to a detonating cap. Over the past years, few researchers have reported the development of various shock tube designs consisting of single, double, and triple polymeric layers. Despite the disclosure of the development of different shock tube designs, none of the researchers presented experimental data enabling one to predict how shock tubes' properties and performance could be affected by the number of polymeric layers and the nature of polymeric materials present in the shock tube. The aim of this investigation was, therefore, to experimentally determine to which extent changing the number of polymeric layers and the type of polymeric materials could vary the properties and performance of a multi-layered shock tube. The methodology used during the investigation involved the extrusion and testing of a standard three-layered shock tube similar to the commercially available high performance shock tube and samples of different recipes of two-layered shock tubes. The three-layered shock tube was made of high density polyethylene in the outer layer, ethylene based ionomer in the inner layer and ethylene acrylic acid copolymer in the intermediate layer. Samples of two-layered shock tubes were made of ethylene based ionomer in the inner layer and various blends of polyethylene/Adhesion promoter in the outer layer.