Stoppers
Stoppers, also known as bungs, are used to give an airtight seal to laboratory flasks and test tubes by fitting tightly inside the neck of the container and preventing material from spilling. Stoppers can be made of glass, cork, rubber, or silicone. They are typically designed with a conical shape, but straight, flanged, and tapered options are also available.
Stoppers are the preferred choice for many applications requiring a tighter seal or a greater degree of chemical resistance. They also provide a good seal when a solution needs to be shaken or mixed without spilling. Stoppers are generally cylindrical in shape and have a tapered bottom end. They may be marked with a stopper number or size on the top and bottom diameters of the stopper. Sizing can vary among manufacturers.
Stoppers are available in a solid design or with holes known as positions placed in the top. Positions allow easy access to the material contained in the sealed vessel by pipettes, tubing, or other equipment without full removal of the stopper.
What Types of Stoppers Are Available?
• Turnover stoppers have external serrations to create an excellent internal seal combined with a flexible turnover sleeve that folds down over the container’s neck to create a double seal
• Serum bottle or vial stoppers have two or three legs with external serrations or straight sides and a flanged top to create an airtight seal
• Straight bromobutyl plug-type stoppers provide a maximum seal for vials and serum bottles with a straight-wall glass finish
• Ultra-pure, straight bromobutyl plug-type stoppers provide high chemical purity and low gas permeability. They offer excellent performance during freeze drying processes such as lyophilization, where stoppers must remain stable during transfer and sublimination phases
• Silicone recessed septa stoppers are non-toxic and have external serrations to create an effective internal seal
Chemglass Life Sciences 45/50 Stopper, Hollow
45/50 Stopper, Hollow. PTFE stopper has a Polypropylene extraction nut permitting easy removal of the stopper from the glass outer joint. The 14/20 and 19/22 are solid, while the larger sizes are hollow.
Chemglass Life Sciences Stopper, Pennyhead, Hollow, 10/18
Stopper, Pennyhead, Hollow, 10/18. Hollow stopper with closed bottom.
Chemglass Life Sciences Septum Stopper, Sleeve Type, for 8mm OD Standard Wall or 9mm OD Medium Wall, Red
Septum Stopper, Sleeve Type, for 8mm OD Standard Wall or 9mm OD Medium Wall, Red. Sleeve type stoppers with a hollow plugs and sleeve extensions that folds down over the neck of a vessel, tubing, etc. The diaphragm can be punctured with a syringe needle, re-sealing after the needle is withdrawn.
Chemglass Life Sciences Stopper, PTFE, Hollow, 19/22
Stopper, PTFE, Hollow, 19/22. Hollow PTFE stopper.
Chemglass Life Sciences Stopper #22, Pennyhead, Flask Length, Solid
Stopper #22, Pennyhead, Flask Length, Solid. All sizes are solid with the exception of the #38 (CG-3018-08) which is hollow.
Chemglass Life Sciences Septum Stopper, Sleeve Type, For 19/22-19/38 Outer Joints, Red
Septum Stopper, Sleeve Type, For 19/22-19/38 Outer Joints, Red. Sleeve type stoppers with a hollow plugs and sleeve extensions that folds down over the neck of a vessel, tubing, etc. The diaphragm can be punctured with a syringe needle, re-sealing after the needle is withdrawn.
Chemglass Life Sciences Stopper, Hex Head, Hollow, 24/40
Stopper, Hex Head, Hollow, 24/40. Hexagonal shaped head of stopper prevents it from rolling off of the bench top. Flat surface will also permit stopper to be inverted and placed on end, thereby preventing possible contamination of ground surface.
Chemglass Life Sciences Septum Stopper, Sleeve Type, For 29/26-29/42 Outer Joints, White
Septum Stopper, Sleeve Type, For 29/26-29/42 Outer Joints, White. Sleeve type stoppers with a hollow plugs and sleeve extensions that folds down over the neck of a vessel, tubing, etc. The diaphragm can be punctured with a syringe needle, re-sealing after the needle is withdrawn.
Foxx Life Sciences Borosil® Solid Penny Head Glass Stopper with Interchangeable Ground Joint 7/16, 20/CS
Borosil® Solid Penny Head Glass Stoppers are with Interchangeable Ground Joint and can be used with Volumetric Flask of 5645, 5647 families or for other suitable joints. Manufactured with low extractable quality grade USP Type I, 3.3 Borosilicate Glass confirming to ASTM E438 Class A requirements. Available in sizes of 7/16 to 55/54. In collaboration with Borosil Glass Works, Foxx Life Sciences is proud to bring the outstanding quality of Borosil® Type 3.3 Borosilicate glassware to North America for the first time. Manufactured from the same USP Type I, Borosilicate glass that North American scientists have come to trust, Borosil® Laboratory Glassware offers unparalleled mechanical strength, clarity, and reliability at competitive prices. And thanks to a unique annealing process, Borosil® Glassware is stress-free and incredibly resistant to thermal shock.