Abstract: An assembly comprising: a tube made of resilient material, at least a portion of the tube forming a circumferential boundary of a chamber; first and second end cap assemblies supporting the tube at opposite ends thereof and forming respective end boundaries of the chamber, the chamber being filled with pressurized fluid; a hard roller that forms a nip with the tube; a fixed structure that supports the first and second end cap assemblies and the hard roller, the first and second end cap assemblies and the hard roller being respectively pivotably coupled to the fixed structure, and the fixed structure comprising a passageway that is in fluid communication with the chamber; and a slider-zipper-film assembly that is passed through the nip. The tube is deformed radially inward to allow passage of slider through the nip.